Ethical issues and controversies in assisted reproductive technologies. The current ethical issues and controversies concerning in vitro fertilization revolve around micromanipulation of the gametes, cryopreservation of the fertilized ova, selective termination in multiple pregnancies, surrogacy, and gamete donation. At the basis of these ethical issues is the philosophic question of personhood, or the term "human person," and the consideration given to the normal weight that is ascribed to the various forms of living matter that are found in the process of development after human spermatozoa have been placed together with harvested oocytes in the petri dish. The papers of very special importance and special importance written during the past year on these ethical problems are listed and classified. The summaries of their arguments and positions on these problems are enumerated.


Short-term hospital care for psychiatric illness among seniors. This study focuses on recent changes in hospital use by seniors (aged 65 or over) who have been treated as inpatients in general and psychiatric hospitals for less than one year with functional psychoses and clinical disorders. The data analyzed are hospital separations for the age groups 65 to 74, 75 to 84, and 85 and over, for the period 1980-89. The data are derived from hospital morbidity statistics submitted annually to Statistics Canada by the provincial ministries of health. Age-specific separation rates for the age groups 75 to 84, and 85 and over increased during 1980-89. However, for the age group 65-74, the rates were fairly stable and in some instances decreased. These increases in short-term hospitalization of the seniors 75 and over are evidence of the appreciation of their treatability and of the improved recognition of these disorders in this age group. Adverse reactions to prescription drugs resulting in psychiatric symptoms may also be a factor in the increasing hospitalization rates. The largest increases in age-specific rates and bed days were for the age group 85 and over. For this age group, the separation rates were higher for men than women. In this age group in 1986, a higher proportion of women than men lived in institutions. For seniors living outside institutions, a larger percentage of men than women lived alone. This situation likely promotes more social isolation for men than women, and may be an important factor in the higher hospitalization rates among men.


Place of birth and ethnic status: factors associated with smoking prevalence among Canadians. The prevalence of smoking is lower among foreign-born (16%) than among native-born Canadians (25%). In addition, foreign-born smokers smoke fewer cigarettes a day than the native-born. Foreign-born Canadians also tend to smoke cigarettes with a lower tar yield. The differences in the smoking behaviour of foreign-born and native-born Canadians suggest that the foreign-born may be at lower risk from smoking related morbidity and mortality. National smoking rates conceal wide variations in smoking prevalence by ethnic group. The highest smoking rates in Canada are found among Canadian Aboriginals. About 59% of Aboriginal Canadians smoke on a regular basis. In contrast, only 11% of Asian Canadians smoke regularly. These marked differences in smoking rates among ethnic groups are an argument for addressing the unique behaviour of each ethnic group within existing health promotion programs. Four out of ten smokers (42%) attempts to quit smoking during the course of a year. This percentage does not vary much by gender or by foreign-born/native-born status. The high percentage of smokers who attempt to quit during a year probably reflects the combined impacts of smoking prevention programs, increased taxation on cigarettes, and smoking restrictions on smoking in the workplace and in public settings.


Expression and secretion of an assembled tetrameric CH2-deleted antibody in E. coli. We have expressed in E. coli a functional assembled antibody variant that is secreted into the media. The antibody variant is a CH2-deleted chimeric antibody 14.18, which was previously shown to be a potentially useful reagent for radioimmunodetection of human tumors. The bacterial expression vector contains a dicistronic unit comprised of a L-chain cDNA and a CH2-deleted H-chain cDNA. For translocation across the bacterial membranes, we have replaced the natural signal peptides of the H and L chains with the signal peptide of the bacterial protein pectate lyase B. When expressed in the JM105 host under the control of the trp-lac promoter, the products were secreted into the M9 growth media to about 350 micrograms/L. The secreted antibody, which can be readily purified from the media without any denaturation or renaturation steps, retains antigen-binding activity. SDS-PAGE and nondenaturing size exclusion high-pressure liquid chromatography showed that it is a mixture of assembled HL and fully assembled H2L2. In H2L2, inter-H chain disulfide bonds are not formed, and the two HL half-molecules are likely held together by the trans interaction between the two CH3 domains.


Stable expression of cloned human antibody genes in murine myeloma cells. Human monoclonal antibodies (MAbs) offer potential advantages over murine MAbs for therapy because they are not likely to elicit immune responses and are expected to interact more efficiently with the human immune system to activate therapeutically useful functions. Traditional methods for obtaining human MAbs (i.e., immortalization of B cells by cell fusion or transformation) can result in low and unstable antibody secretion. Recently, methods have been devised for direct cloning of human variable region genes via polymerase chain reaction and phage combinatorial libraries. Both types of human MAb production can benefit from expression systems that support the stable, high-level antibody secretion required for therapeutic use. Using an existing human-derived hybridoma that secretes a human IgM antibody as a convenient source of antibody genes, we have demonstrated that cloned human antibody genes can be efficiently expressed in murine myeloma cells and that cell lines with properties suitable for large-scale economical production can be obtained. We were unable to detect any differences between the antibodies produced by the original hybridoma and the engineered cell line. In addition, we were able to express an IgG form of the antibody, showing that expression of a recombinant human antibody need not be limited to the original antibody class.


Preparation of genetically engineered monoclonal antibodies for human immunotherapy. Production of human monoclonal antibodies (MAbs) of predefined specificity using conventional hybridoma technology has proved to be difficult. Immunotherapeutic intervention in humans with rodent MAbs, however, is disadvantageous because of the antigenicity of these proteins and may result in human antibody responses against this foreign agent. To circumvent this problem, recombinant DNA techniques have been developed to transplant the specificity of a rodent MAb into a human antibody. Two basic approaches are being employed: first, combining rodent MAb variable regions with human constant regions; and more recently, "reshaping" human MAbs by grafting complementarity-determining regions (CDR) into the human antibody framework. These humanized MAbs can now be used to study human Fc-dependent effector mechanisms in detail, which seems essential to optimize potential in vivo application.


Rescue and expression of human immunoglobulin genes to generate functional human monoclonal antibodies. Human monoclonal antibody production has been hampered for many years by the instability of cell lines and low levels of expression of the antibodies. We describe here the rescue of human immunoglobulin genes utilizing micro-mRNA preparation from a small number of human hybridoma cells and conventional cDNA cloning. This allows cloning and immediate high-level expression from full-length human heavy and light chain cDNA molecules and provides a mechanism to rescue whole human monoclonal antibodies of proven efficacy.


Variable region differences affect antibody binding to immobilized but not soluble antigen. We have examined the antigen binding characteristics of two chimeric IgG1 antibodies that differ only in the heavy chain variable region. Antibodies 10B and B11 were expressed from two different anti-(Tyr,Glu)-Ala-Lys murine VH genes joined to human IgG1 constant region genes in a murine anti-(Tyr,Glu)-Ala-Lys heavy chain loss variant hybridoma. The binding characteristics of the antibodies to (Tyr,Glu)-Ala-Lys and to a peptide conjugate, CYYYEEEEY:BSA, were measured in solution and solid phase assays. The antibodies exhibited similar affinities and binding characteristics when assayed in solution assays. However, when we measured binding of antibodies to immobilized antigens, we found that antibody affinity depended on the epitope density in the immobilized immune complexes. The binding of antibody 10B and of B11 to immobilized (Tyr,Glu)-Ala-Lys and to CYYYEEEEY:BSA were similar at high antigen density, but antibody B11 bound less well at lower antigen density. Fab fragments of 10B bound to immobilized (Tyr,Glu)-Ala-Lys and CYYYEEEEY:BSA, but Fab fragments of B11 did not bind to (Tyr,Glu)-Ala-Lys and bound less well to CYYYEEEEY:BSA than 10B Fabs.


Nutritional patterns and weight change in Alzheimer patients. A nutritional study of 100 patients enrolled in an active geriatric outpatient teaching program was conducted to document the clinical impression of weight loss in Alzheimer's disease. All new patients were asked to complete a questionnaire on nutrition. Patients were evaluated by a geriatrician, then categorized using DSM-III and NINCDS-ADRDA criteria. There were 34 Alzheimer patients and 60 nondemented patients with an average weight of 56.2 kgs and 66.1 kgs, respectively (p less than .002). Of the Alzheimer group, 44% reported weight loss in the past five years compared with 37% of the nondemented group, despite a concomitant increase in food intake in 35% versus 7%, respectively. On a one-year follow-up, 92% of Alzheimer patients lost weight, whereas 57% of the nondemented patients actually gained weight. The increase in reported food intake, with a significant concomitant weight loss, raises some challenging questions as to the existence of a hypermetabolic state in Alzheimer's disease.


Memory improvements and pharmacological treatment: a method to distinguish direct effects on memory from secondary effects due to attention improvement. Chronic cerebrovascular disturbances of the aged are characterized by a decline of attention. When these patients undergo pharmacological treatment, it is very difficult to distinguish between a direct benefit and/or a secondary effect on memory resulting from attention improvement. In our study we have proposed and evaluated a new method for identifying the different components of therapeutic efficacy on memory and attention in chronic cerebrovascular patients. This method is based on the use of the Randt Memory Test, traditional scores of memory efficiency (Acquisition, Recall, and a combined index), and the RMT three-factor scores derived from a structural model of memory functioning. The three scores have been called Encoding and Organization, Cognitive Efficiency, and Attention Efficiency. Participants were 96 selected chronic cerebrovascular patients treated in a double-blind study for 12 weeks with dihydroergocristine versus placebo. While changes in both acquisition and recall scores were related to the treatment, only changes of the Encoding and Organization factor scores were systematically related to therapy. Changes in Attention Efficiency were positively related to therapy only in proportion to the degree of cerebrovascular impairment.


Applying cognitive-behavioral psychotherapy to the chronically ill elderly: treatment issues and case illustration. A large percentage of older adults must endure at least one chronic medical illness. Clinically significant depression and anxiety are common among these patients. Specific psychotherapy approaches as well as adaptations required to address the unique issues of this population have not been delineated in the literature. We outline a cognitive-behavioral therapy approach and discuss five treatment issues we have found to be important for this population. These issues include: (1) resolving practical barriers to participation; (2) accepting depression as a separate and reversible problem; (3) limiting excess disability; (4) counteracting the loss of important social roles and autonomy; and (5) challenging the perception of being a "burden." A case study of a chronic obstructive pulmonary disease (COPD) patient with depression is presented and recommendations for future research are suggested.


Geriatric psychopathology: an American perspective on a selected agenda for research. The authors present an overview of research questions related to psychopathology in elderly patients. Specific research questions in the areas of organic mental disorders, affective disorders, personality disorders, anxiety disorders, psychotic disorders, and substance abuse are presented. Clinical investigators are encouraged to pursue some of these specific questions in order to facilitate diagnosis and to develop specific effective treatment strategies for psychopathology in older patients.


Moving from the question of efficacy to the question of therapeutic relevance: an exploratory reanalysis of a controlled clinical study of 130 inpatients with dementia syndrome taking piracetam. The authors reanalyzed previously published data from a prospectively randomized, placebo-controlled, double-blind phase-III study of 130 inpatients with dementia syndrome. The patients in the study had been diagnosed as having suffered from organic brain syndrome (ICD 290), which is the core syndrome of dementia (so-called dementia syndrome) for at least two years. They were treated with piracetam for three months at a dose level of 4,800 mg/d. These data were reexamined in order both to survey the extent of drug-related improvement and response rates when assessed at different levels and to investigate the comparability of efficacy in subgroups suffering from either senile dementia of the Alzheimer type or multi-infarct dementia. Three scales were used for the assessment of efficacy. They were the CGI, or Clinical Global Impression, completed by the physicians; the SCAG, or Sandoz Clinical Assessment Geriatric, used by clinical psychologists; and the BGP, or Beurteilungsskala für Geriatrische Patienten (Evaluation Scale for Geriatric Patients), employed by the nursing staff. The Syndrome-Kurztest (SKT) and Benton tests served to measure performance. The items and subscores of the SCAG and the SKT were highly intercorrelated at baseline, forming a common factor fairly independent of the information gained by BGP. This suggests that merely using different kinds of information-gathering methods, i.e., clinical scales and performance tests, completed by different groups of observers, does not automatically result in nonredundant comprehensive information. When using the most conservative response criterion of individual improvement, i.e., at least one baseline standard deviation, treatment with piracetam showed statistically significant (pe less than .001) explorative response rates of 50% and above in three out of four target variables, as compared to the 0 to 6% obtained with placebo. CGI was used as descriptive variable. Again, using this response criterion from a separate analysis of diagnostic subgroups, as matched by the median of the patients' Hachinski Ischemic Scale scores, it does not appear that piracetam's efficacy for patients with senile dementia of the Alzheimer type (SDAT) varies with its efficacy for patients with multi-infarct dementia (MID).


A double-blind comparison of the effects of temazepam and triazolam on residual, daytime performance in elderly insomniacs. Benzodiazepine hypnotic medications are widely prescribed for elderly patients, but there is a paucity of information available concerning the residual cognitive and psychomotor (the morning-after) effects of these drugs. We compared two commonly used hypnotics--temazepam and triazolam--in a double-blind, placebo-controlled, single-dose study with community-dwelling healthy elderly with a DSM-III-R diagnosis of primary insomnia. Forty-five subjects over the age of 65 (mean age 72.23, SD = 4.44) qualified for the study. Subjects were randomly assigned to one of five treatment groups (placebo, triazolam 0.125 mg., triazolam 0.25 mg., temazepam 15 mg., and temazepam 30 mg.). Neuropsychological testing was completed at baseline and 12-14 hours after the dosing. Patients were evaluated with a variety of tests that measured attention, concentration, motor speed, immediate memory, and learning of new information. Separate repeated measured analyses of variance were performed to assess the significant changes among the five treatment groups. We found improved performance or no change in all the measures for all medication groups except for impairment of performance on a serial learning task for both high-dose medication groups. The significance of these results and the need for further research in elderly insomniacs is discussed.


Assessing Alzheimer severity with a global clinical scale. Diagnosis of dementia needs to be complemented by precise determination of disease severity across the broad spectrum of disease progression. The Mini-Mental State Exam (MMS), the Activities-of-Daily-Living assessment (ADL) and the Clinical Dementia Rating scale (CDR) were modified for direct comparability and administered to 112 outpatients and 45 nursing home residents with a range of dementia severity from mild to profound. The scales showed the highest correlations for the probable Alzheimer's disease patient group (62) (Global Assessment of Dementia; GAD vs. ADL: r = 0.91; Extended Mini-Mental Assessment; EMA vs. GAD: r = 0.91; ADL vs. EMA: r = 0.86). For these patients, scores on the individual scales tended to be similar. Disparity among the three scores for individual cases was associated with the presence of comorbidities. The high correlations and correspondence among these scales demonstrate their reliability, validity, and utility in the assessment of dementia severity. The use of an average of these measures, with their increased precision, may give a more accurate indication of dementia severity over a broader range of impairment.


Relationships among the symptoms of the elderly as revealed by multivariate analysis: a preliminary study. One hundred and sixty-eight elderly subjects in a geriatric hospital and the adjoining nursing home were examined in a study of relationships among the items of Hasegawa's dementia scale. A three-dimensional model using multivariate analysis demonstrated the relationships among items. The results led to the identification of six clinical groups determined by the presence of stroke and the score on the dementia scale. Nonstroke subjects of middle intellectual level had disturbances of memory and orientation. This group fell into two categories during the course of a five-year follow-up study: severe dementia and intellectual deterioration. Retrospective multivariate analysis results suggested that features characteristic of the severe intellectual deterioration group were earlier disturbances of orientation and distant memory. This statistical method uses only objective clinical data in order to avoid subjective and, often, biased judgments.


Longitudinal changes in computerized EEG and mental function of the aged: a nine-year follow-up study. Computer-analyzed EEG data and mental functions of the healthy aged (28 survivors and 20 nonsurvivors) were followed for nine years in a study of their relationship with age and longevity. The study revealed that decrease in fast waves occurred from early senescence. The slowing of EEG, the increase in theta waves, and the decrease in alpha frequency became obvious in late senescence, after the late 70s or beyond 80 years. The amount of alpha waves was maintained until the early 80s. The decline of mental functions occurred with the slowing of EEG in late senescence. The slowing of EEG and the lowered scores of psychometrics were closely related to the longevity of life, comparing the survivors and nonsurvivors in retrospect.


Usefulness of the Neurobehavioral Cognitive Status Examination in the hospitalized elderly. A prospective pilot study compared the Neurobehavioral Cognitive Status Examination (NCSE) to the Folstein Mini-Mental State Examination (MMSE) to determine the usefulness of the NCSE as a cognitive screen in a geriatric inpatient population. All patients directly admitted to the geriatric evaluation and treatment unit (GETU) of a university teaching hospital over a two-and-a-half-month period were eligible for the study, in which 42% participated. Within 72 hours of admission, patients were given the MMSE and the NCSE in a nonrandom order by a trained psychologist and a structured interview by a psychiatrist. The ability of the NCSE to detect global cognitive impairment was compared to the MMSE and psychiatrist's assessment. Differences in sensitivity were examined by discordant pair analysis. The psychiatrist's determination of the presence of cognitive impairment was used as the criterion standard. Comparisons of the MMSE and NCSE, respectively, revealed the following: sensitivity 83% versus 100%; specificity 78% versus 11%; positive predictive value 83% versus 43%; and negative predictive value 78% versus 100%. Seven patients who were cognitively impaired by the NCSE were not impaired by the MMSE (p less than 0.05 by discordant pair analysis). The time of administration for the two tests was significantly shorter for the MMSE (14.75 +/- 5.7 minutes) than for the NCSE (38.9 +/- 12.9 minutes). The NCSE was found to be more sensitive than the MMSE in detecting cognitive impairment among geriatric inpatients, but its specificity and positive predictive values were lower. Beyond this pilot study, additional work examining the utility of the NCSE in other geriatric settings and for different purposes (e.g., as part of comprehensive assessment) needs to be performed.


Prediction of the volume of distribution of 7-hydroxycoumarin in man from in vitro and ex vivo data obtained in rat. The essential parameter to estimate the first dose size of a drug in man is the volume of distribution. For a drug that has never been used in man before, estimates of the volume of distribution can only be obtained from animals and in vitro data. The purpose of this study was to compare various approaches presented in the literature for predicting the volume of distribution at steady state (VSS) and the terminal phase volume of distribution (Vd beta) in man. A lipophilic active metabolite of coumarin, 7-hydroxycoumarin (7OHC), was selected for this investigation. This compound is extensively metabolized in both the central and peripheral compartments. Of the six methods evaluated, only an empirical allometric approach yielded a reasonable estimate of VSS. All methods underestimated VSS and none of the applicable methods were able to predict Vd beta. The reason for this discrepancy may be due to the fact that the calculation of VSS in man was done assuming elimination from the central compartment.


Influence of probenecid and paracetamol (acetaminophen) on zidovudine glucuronidation in human liver in vitro. The effects of probenecid and paracetamol on zidovudine glucuronidation were investigated, in vitro, using human liver microsomal preparations. The presence of probenecid in the incubation medium significantly reduced the maximum reaction velocity for zidovudine glucuronide formation by more than 60 per cent, and the Km was reduced by 47 per cent, suggesting an uncompetitive inhibition of zidovudine glucuronidation. In contrast, paracetamol had no significant effect on zidovudine glucuronidation. The maximum reaction velocity for zidovudine glucuronide formation and the Km were unchanged when paracetamol (5 mM) was present in the incubation medium. The effects of probenecid and paracetamol on zidovudine metabolism in vitro correlates closely with those observed in vivo. The in vitro system of human liver microsomes may have a useful role in predicting the possible interaction of other drugs with zidovudine metabolism.


Distribution of carbamazepine and its epoxide in blood compartments in adolescent and adult epileptic patients. Carbamazepine (CBZ) used in the treatment of epilepsy, is metabolized in man to an active metabolite: carbamazepine 10-11 epoxide (CBZ-E). CBZ and CBZ-E concentrations in the different blood compartments (plasma ultrafiltrate, plasma proteins, and red blood cells (RBC)) of epileptic patients on CBZ monotherapy were assessed using HPLC. The highest CBZ and CBZ-E level to dose ratios were observed in the RBC. For CBZ and CBZ-E significant correlations were found between some blood compartments particularly between RBC and plasma ultrafiltrate. The measurement of CBZ and CBZ-E in all blood compartments may be interesting in uncontrolled patients and in patients presenting side-effects which cannot be explained by total plasma concentration values.


Studies on the intravenous pharmacokinetics in rabbit and in vitro protein binding of two new salts of erythromycin: erythromycin maltobionate and erythromycin fumarate. Pharmacokinetics in rabbits following intravenous administration and in vitro protein binding were studied for two new salts of erythromycin (erythromycin maltobionate and erythromycin fumarate). Serum erythromycin levels following intravenous injection were described by two compartment model kinetics, and values for the distribution volume of the central compartment, the peripheral compartment and overall distribution volume were calculated. The elimination half-lives of erythromycins in serum were 83 min, 168 min, and 103 min for erythromycin maltobionate, erythromycin fumarate, and erythromycin lactobionate (reference standard), respectively. The erythromycin salts were highly (c. 90 per cent) protein bound, but the binding was found to be reversible. Differences in the pharmacokinetic parameters after administration of equivalent doses of the salts, indicate possible variation in efficacies of different salts.


Pharmacokinetics and metabolism of codeine in humans. Codeine (30 mg phosphate) was metabolized by eight human volunteers to the following six metabolites: codeine-6-glucuronide 81.0 +/- 9.3 per cent, norcodeine 2.16 +/- 1.44 per cent, morphine 0.56 +/- 0.39 per cent, morphine-3-glucuronide 2.10 +/- 1.24 per cent, morphine-6-glucuronide 0.80 +/- 0.63 per cent, and normorphine 2.44 +/- 2.42 per cent. Two out of eight volunteers were unable to O-dealkylate codeine into morphine and lack therefore the cytochrome P450 IID6 isoenzyme. The half-life of codeine was 1.47 +/- 0.32 h, that of codeine-6-glucuronide 2.75 +/- 0.79 h, and that of morphine-3-glucuronide 1.71 +/- 0.51 h. The systemic clearance of codeine was 2280 +/- 840 ml min-1, the renal clearance of codeine was 93.8 +/- 29.8 ml min-1, and that of codeine-6-glucuronide was 122 +/- 39.2 ml min-1. The plasma AUC of codeine-6-glucuronide is approximately 10 times higher than that of codeine. Protein binding of codeine and codeine-6-glucuronide in vivo was 56.1 +/- 2.5 per cent and 34.0 +/- 3.6 per cent, respectively. The in vitro protein binding of norcodeine was 23.5 +/- 2.9 per cent; of morphine, 46.5 +/- 2.4 per cent; of normorphine, 23.5 +/- 3.5 per cent; of morphine-3-glucuronide, 27.0 +/- 0.8 per cent; and of morphine-6-glucuronide, 36.7 +/- 3.8 per cent.


Extended least squares curve fitting: a comparison of SIPHAR and MKMODEL. SIPHAR and MKMODEL in their extended least squares modes have been compared when fitting a triexponential declining function to simulated data. The data were simulated on SAS incorporating normally distributed random error, having coefficients of variation (CV) of 5, 10, 15, and 25 per cent. At each error level 100 data sets, consisting of 21 data pairs, were simulated. Non-parametric tests were used to compare the accuracy and precision of the estimates produced by the packages. The comparison was repeated with two different sets of exponent values incorporating error at the 15 per cent level. MKMODEL was also compared to ELSFIT and ELSMOS at the same error level. SIPHAR was consistently less accurate and less precise than MKMODEL in estimating the structural model parameters. SIPHAR was also sensitive to the concentration units used for the input data. Estimates of the variance model power produced by SIPHAR were very variable while those from MKMODEL covered a much tighter range. For both packages there was generally a linear increase in the CV on each mean parameter estimate with increase in the CV on the error model. Good agreement was observed between MKMODEL, ELSFIT, and ELSMOS. The presence of an additive constant in the variance model used in SIPHAR was shown to be responsible for its poorer accuracy and precision.


6-Dimethyl amino purine and 2-amino purine inhibit the induction of expression of milk protein genes by prolactin. Two protein kinase-inhibitors, 6-dimethyl amino purine and 2-amino purine inhibited induction of beta-casein synthesis by prolactin when added to the culture medium of rabbit mammary explant and cells. The accumulation of the mRNA for alpha s1- and beta-caseins and for whey acidic protein did not take place in the presence of the inhibitors whereas beta-actin mRNA concentration was not altered. In the same experimental conditions, H7, an inhibitor of protein kinase C and, to a lower extent, of protein kinase A did not prevent prolactin from acting. These data suggest for the first time that specific protein kinases are involved in the transduction of the prolactin signal to milk protein genes.


Seasonal commitment of HMGCoA reductase activity to vitellogenin production. In female frogs (Rana Esculenta) during gametogenesis the cholesterol synthesized in the liver by 3-hydroxy-3-methylglutaryl coenzyme A reductase is mostly exported into the blood and taken up by the oocytes. In order to understand the fate of the neosynthesized cholesterol, female and male frogs and estrogenized male controls were injected with the labelled precursor 14C mevalonate. In females and in estrogenized controls, mevalonate-derived radioactivity is found in a plasmatic lipoprotein that has been identified as vitellogenin by immunological detection. The increased 3-hydroxy-3-methylglutaryl coenzyme A reductase activity present in females in Fall is likely to be committed to provide cholesterol for the lipidation of this cholesterol-rich protein.


Changes in membrane permeability during Semliki Forest virus induced cell fusion. The infection of Aedes albopictus cells by Semliki Forest virus (SFV) is a non lytic event. Exposure of infected cells to mildly acidic pH (less than 6.2) leads to syncytium formation. This polykaryon formation is accompanied by an influx of protons into the cells (Kempf et al. Biosci. Rep. 7, 761-769, 1987). We have further investigated this permeability change using various fluorescent or radiolabeled compounds. A significant, pH dependent increase of the membrane permeability to low molecular weight compounds (M(r) less than 1000) was observed when infected cells were exposed to a pH less than 6.2. The pH dependence of the permeability change was very similar to the pH dependence of cell-cell fusion. The permeability change was sensitive to divalent cations, protons and anionic antiviral drugs such as trypan blue. The nature of this virus induced, pH dependent permeability change is discussed.


The definitions of metabolic control analysis revisited. Various definitions of coefficients in metabolic control analysis are examined with respect to their theoretical consistency and practical applicability. We suggest agreement upon a definition for control coefficients which is clearly distinct from that for response coefficients, in such a way that the former describe inherent properties of the metabolic system while the latter refer to the influence of special parameters. Advantages and drawbacks of using normalized or non-normalized control coefficients are studied. It is shown that normalized control coefficients have the advantage of being invariant to a different rescaling of the particular fluxes. We demonstrate that some problems are easier to tackle if the consistency of time-independent control coefficients with their time-dependent counterparts is taken into account. It is shown that the matrix of flux control coefficients is an indempotent matrix. This allows an interpretation in terms of the transduction of the effect of parameter perturbations. Several aspects of the experimental measurement of control coefficients are discussed, with special reference to the different definitions.


The cell division cycle: a physiologically plausible dynamic model can exhibit chaotic solutions. A mitotic oscillator with one slowly increasing variable (tau L of the order of hours) and one rapidly increasing variable (tau R of the order of minutes) modulated by a timer (ultradian clock) gives an auto-oscillating solution: cells divide when this relaxation oscillator reaches a critical threshold to initiate a rapid phase of the limit cycle. Increasing values of the velocity constant in the slow equation give quasi-periodic, chaotic and periodic solutions. Thus dispersed and quantized cell cycle times are consequences of a chaotic trajectory and have a purely deterministic basis. This model of the dispersion of cell cycle times contrasts with many previous ones in which cell cycle variability is a consequence of stochastic properties inherent in a sequence of many thousands of reactions or the random nature of a key transition step.


Effects of afterhyperpolarization on neuronal firing. Stein's model for a neuron is studied. This model is modified to take into account the effects of afterhyperpolarization on the neuronal firing. The relative refractory phase, following the absolute one, is modelled by a time-increasing amplitude of postsynaptic potentials and it is also incorporated into the model. Besides the simulation of the model, some theoretical results and approximation methods are derived. Afterhyperpolarization tends to preserve the linearity of the frequency transfer characteristic and it has a limited effect on the moments of the interspike intervals in general. The main effects are seen at high firing rates and in the removal of short intervals in the interspike interval histogram.


Biodiversity: molecular biological domains, symbiosis and kingdom origins. The number of extant species of organisms is estimated to be from fewer than 3 to more than 30 x 10(6) (May, 1992). Molecular biology, comparative genetics and ultrastructural analyses provide new insights into evolutionary relationships between these species, including increasingly precise ideas of how species and higher taxa have evolved from common ancestors. Accumulation of random mutations and large macromolecular sequence change in all organisms since the Proterozoic Eon has been importantly supplemented by acquisition of inherited genomes ('symbiogenesis'). Karyotypic alterations (polyploidization and karyotypic fissioning) have been added to these other mechanisms of species origin in plants and animals during the Phanerozoic Eon. The new evolution concepts (coupled with current rapid rates of species extinction and ignorance of the extent of biodiversity) prompted this analysis of the field of systematic biology and its role in the reorganization of extant species into higher taxa. Two superkingdoms (= Domains: Prokaryotae and Eukaryotae) and five kingdoms (Monera = Procaryotae or Bacteria; Protoctista: algae, amoebae, ciliates, foraminifera, oomycetes, slime molds, etc.; Mychota: 'true' fungi; Plantae: one phylum (division) of bryophytes and nine phyla of tracheophytes; and Animalia) are recognized. Two subkingdoms comprise the monera: the great diverse lineages are Archaebacteria and Eubacteria. The criteria for classification using molecular, ultrastructural and genetic data for this scheme are mentioned. For the first time since the nineteenth century, logical, technical definitions for each group are given with their time of appearance as inferred from the fossil record in the primary scientific literature. This classification scheme, which most closely reflects the evolutionary history, molecular biology, genetics and ultrastructure of extant life, requires changes in social organization of biologists, many of whom as botanists and zoologists, still behave as if there were only two important kingdoms (plants and animals).


Phylogenetic consequences of symbioses: Eukarya and Eubacteria are not monophyletic taxa. In the past systematists have not been concerned with distinguishing the different phylogenetic histories for symbiont taxa that have merged within a composite taxon, or holobiont. I suggest that symbionts can retain their status as discrete taxa and that their independent histories can be included in phylogenetic analyses intending to discover monophyletic groups. Use of reticulate branches to include independent histories for different symbionts, incorporates our improving understanding of evolution and provides greater accuracy in denoting monophyletic groups. In an expanded view, a monophyletic group includes only and all the descendants of the merged-symbionts' common ancestor. Holobiont taxa will have constituent symbionts included in different monophyletic groups and there will be a reduction in the number of monophyletic groups recognized, particularly at higher taxonomic levels. As a consequence of considering symbioses in phylogenetic analyses, the proposed taxa Eubacteria and Eukarya are seen to be non-monophyletic, and, thus, poor indicators of evolutionary history.


DMBA-induced intestinal tumors in the Japanese house musk shrew, Suncus murinus (Insectivora). Intestinal tumors were induced in the Japanese house musk shrew, Suncus murinus (Family: Soricidae, Order: Insectivora) with 7,12-dimethylbenz(a)anthracene (DMBA). The animals were divided into 10 groups: groups 1-4 received gastric intubation of DMBA, groups 5-8 received intraperitoneal (i.p.) injections of this agent, and groups 9 (female) and 10 (male) were untreated and served as controls. Group 1 (females) and group 2 (males) received 10 mg DMBA at 50 days of age; group 3 (females) and group 4 (males) received 2 x 10 mg doses at 50 and 55 days of age; groups 5 and 6 (females) received weekly i.p. administration of 1.25 mg (group 5) and 2.5 mg (group 6) for 4 weeks; and groups 7 and 8 (females) received weekly i.p. administration of 1.25 mg (group 7) and 2.5 mg (group 8) for 8 weeks from 8 weeks of age. Intestinal tumors developed in 3/8 (38%) animals in group 1, 2/6 (33%) in group 2, 5/11 (45%) in group 3, 5/10 (50%) in group 4, 3/6 (50%) in group 5, 2/4 (50%) in group 6, 5/8 (63%) in group 7, and 5/6 (83%) in group 8, but not in untreated shrews up to 50 weeks of age. The induced tumors, which began to appear by 15 weeks after the initial treatment, were randomly distributed throughout the intestine. Histologically, the lesions were classified as adenocarcinomas similar to those found in humans. BrdU immunohistochemistry indicated an extension of the proliferative zone and labeling of many neoplastic cells. Local invasion was seen but no metastasis was observed.(ABSTRACT TRUNCATED AT 250 WORDS)


Effects of postpubertal treatment with progesterone on protein expression in the vagina and uterus of mice exposed neonatally to diethylstilbestrol. Postpubertal progesterone injections slightly inhibited the proliferation and cornification of the vaginal epithelium induced by neonatal injections of diethylstilbestrol (DES). In vaginae of neonatally DES-exposed mice (DES mice), 9 protein expressions (PEX) appeared newly; 13 PEX decreased; 5 PEX increased compared to those in the controls. In vaginae of DES mice, PEX were altered by postpubertal injections of progesterone (DES-P); 3 PEX disappeared; 11 PEX were reversed to those in the controls. Progesterone injections impaired the proliferation of the vaginal epithelium, reversing 11 PEX compared to those in DES mice. In uteri of DES-P mice, 3 PEX increased, 2 PEX decreased, 2 PEX appeared and 1 PEX disappeared compared to those in DES mice. In conclusion, it was shown that postpubertal injections of progesterone alter the protein expression in the vagina and uterus of DES mice.


Effects of postpubertal treatment with diethylstilbestrol and tamoxifen on protein expression in the vagina and uterus of neonatally diethylstilbestrol-exposed mice. Postpubertal injections of a synthetic estrogen, diethylstilbestrol (-DES), and an anti-estrogen, tamoxifen (-Tx), stimulate proliferation of vaginal and uterine epithelial cells of ovariectomized (OVX) adult mice. In vaginae of two groups of OVX mice treated neonatally with DES (DES-) and oil vehicle alone (Oil-), postpubertal injections of DES altered all and 25 out of 37 protein expressions examined, except for keratin polypeptides, respectively. Twenty-one of the DES- and Tx-altered protein expressions showed the same behavior, suggesting that Tx acts as an estrogen agonist on these proteins. Both neonatally Oil- and DES-treated OVX mice given postpubertal injections of DES (Oil-DES and DES-DES) and Tx (Oil-Tx and DES-Tx) showed similar histological changes in the vagina. Epithelial proliferation and superficial cornification were observed in vaginae of five groups of Oil-DES, Oil-Tx, DES-DES, DES-Tx and DES-Oil (given oil postpubertally) OVX mice. In these groups, 13 proteins showed the same behavior, implying that these proteins are related to proliferation and cornification of mouse vagina. The histology of the uterus in DES-Oil OVX mice closely resembled that in Oil-Oil OVX mice; in protein expressions of the uterus, 5 proteins in DES-DES and 7 proteins in DES-Tx OVX mice were different from those in Oil-DES and Oil-Tx OVX mice, respectively. These findings indicate that neonatal DES treatment alters the behavior of the vagina and uterus in response to postpubertally administered DES and Tx.


Inhibitory effects of biochanin A on benzo(a)pyrene induced carcinogenesis in mice. Biochanin A was studied for its capacity to inhibit benzo(a)pyrene (BP) induced neoplasia in female Swiss Webster mice. To investigate the effect of biochanin A on the initiation step, biochanin A (500 mg/kg) was administered orally 48 hours prior to BP (3 mg/mouse), which was also given orally. This sequence of biochanin A and BP administration was repeated once a week for a total of 4 weeks. At 26 weeks after the last treatment, all the mice were sacrificed. To investigate the effect of biochanin A on the promotion step, a single subcutaneous injection of 0.5 mg of BP was given within 24 hours after birth, and biochanin A (0.125 mg/mouse) was injected intraperitoneally 3 times a week for 6 weeks after weaning. In the initiation protocol, the concomitant administration of biochanin A showed significant inhibition of the mean number of lung tumors (P less than 0.001) and the incidence of carcinoma of the forestomach (P less than 0.02). In the promotion protocol, biochanin A significantly inhibited the incidence (P less than 0.01) and the multiplicity (P less than 0.001) of pulmonary adenoma, compared with the group treated with BP alone. These results suggest that biochanin A inhibitory potential in the initiation, as well as in the promotion step of BP carcinogenesis in female Swiss-Webster mice.


Vascular access: concepts for the 1990s. Modern hemodialysis requires repeated reliable access to blood vessels capable of providing rapid extracorporeal blood flow. This necessity for reliable access to the circulation is the Achilles' heel of modern hemodialysis. Native and synthetic arteriovenous fistulas remain the preferred method of maintaining long-term hemodialysis access. Vascular access dysfunctions (thrombosis and infection) are the most common complications encountered in the care of end-stage renal disease patients. This article focuses on the mechanisms by which permanent vascular access for hemodialysis is obtained and deals with the common complications that result. This review will evaluate these common complications and outline new methods for improving vascular access patency. New concepts focusing on the prospective detection and correction of venous stenoses as well as on the prevention of other factors that predispose to access failure are explored.


Modification of the percutaneous approach to peritoneal dialysis catheter placement under peritoneoscopic visualization: clinical results in 78 patients. The placement of percutaneous peritoneal dialysis catheters under direct peritoneoscopic visualization is a relatively new technique for establishing peritoneal dialysis access. In this study, in which a modification of the Seldinger technique was used to facilitate the placement of the peritoneoscope, the experience with 82 consecutive catheterization procedures in 78 patients is reported. In 2 (2.4%) of 82 catheterization procedures, we were unable to enter the peritoneal cavity but experienced no other complications unique to the percutaneous approach. Of the 80 successful catheterization procedures, 76 represented first-time catheter placement and constituted a population subjected to life-table analysis examining catheter survival rates, the time to first cutaneous exit site or s.c. tunnel infection, and the time to first episode of peritonitis. After a follow-up period of 50.1 patient yr, 11 catheters were lost because of catheter dysfunction. Other clinical complications included peritoneal fluid leaks at the cutaneous exit site in 11 instances (0.22/patient yr), cutaneous exit site infection in 7 instances (0.14/patient yr), s.c. tunnel infection in 2 instances (0.04/patient yr), and 34 episodes of peritonitis (0.68/patient yr). The results of this study demonstrate that the suggested modification of the percutaneous placement of peritoneal dialysis catheters, under peritoneoscopic visualization, is a viable method for establishing peritoneal access.


Expression of epidermal growth factor, transforming growth factor-alpha and epidermal growth factor receptor in thyroid tumors. Immunohistochemical study of epidermal growth factor (EGF), epidermal growth factor receptor (EGFR) and transforming growth factor-alpha (TGF-alpha) expression was performed on paraffin-embedded tissue specimens of 12 follicular carcinomas, 15 papillary carcinomas and 15 adenomas of the thyroid gland. The tumors were placed in one of the following eight groups, according to the results of EGF, TGF-alpha and EGFR expression: group 1: none, group 2: only EGFR, group 3: EGFR and TGF-alpha, group 4: EGFR and EGF, group 5: TGF-alpha, and EGF, group 6: all three, group 7: only TFG-alpha and, finally, group 8: only EGF. Statistical analysis of the results revealed that the ratio of thyroid carcinomas with lymph node metastasis was significantly higher in groups 3 and 6 for follicular carcinomas (P less than 0.01) and in groups 4, 5 and 6 for papillary carcinomas (P less than 0.01). These results suggest that thyroid carcinomas expressing the systems EGF/EGFR, TGF-alpha/EGFR or TGF-alpha/EGF/EGFR display pathologic features of more aggressive disease. Furthermore, the synchronous expression of EGF, TGF-alpha and EGFR indicates that these carcinomas may regulate their growth by an autocrine and/or paracrine mechanism.


Simultaneous measurements of glomerular filtration rate by two radioisotopic methods in patients without renal impairment. Isotopic clearance techniques have been widely used to measure GFR but may give variable results depending on the level of renal function and the technique used. GFR, measured by the technique of plasma disappearance of 99mTc-labeled diethylenetriaminopentacetic acid ([99mTc]DTPA) was compared with simultaneously obtained urinary clearance of [99mTc]DTPA. GFR was also measured by concurrent 24-h clearance of creatinine. Forty-six measurements of GFR were obtained in 12 patients who had no evidence of renal disease. Plasma disappearance was measured from three timed plasma samples collected 60 to 180 min after the bolus injection of 200 microCi of [99mTc]DTPA and was calculated as the product of the volume of distribution (milliliters) at time zero and the clearance rate (per minute) as determined by the regression of the monoexponential plot. Urinary clearance was measured as the average of 3 1-h urinary clearances collected after a water diuresis was established. GFR measured by plasma disappearance was significantly greater (P less than 0.001) than GFR measured simultaneously by urinary clearance. There was a linear correlation between GFR measured by urinary clearance and that measured by plasma clearance (r = 0.994). Plasma clearance exceeded urinary clearance by a constant factor of 1.3 over the range studied (urinary clearance range, 49 to 94 mL/min/1.73 m2). It was concluded that at relatively a normal GFR, the plasma clearance of [99mTc]DTPA consistently overestimates the urinary clearance of [99mTc]DTPA.


Diagnostic accuracy of ultrasound, computed tomography and endoscopic retrograde cholangiopancreatography in the detection of pancreatic cancer in patients with jaundice or cholestasis. A prospective study of jaundiced and/or cholestatic patients (N = 220) was carried out to evaluate the diagnostic accuracy of ultrasound (US), computed tomography (CT) and endoscopic retrograde cholangiopancreatography (ERCP) in the detection of pancreatic cancer. Thirty-one patients had the final diagnosis of pancreatic cancer and two patients had a cancer of the papilla of Vater. The sensitivities of US, CT and ERCP were 60%, 97%, 89% and specificities were 92%, 92%, 94%, respectively. The differences in sensitivity between US and other methods were statistically significant (US vs. CT p less than 0.01, US vs. ERCP p less than 0.05). In US studies, most false negative results were caused by unsatisfying visualization. On the basis of this study, we recommend CT as a diagnostic test of pancreatic cancer, if pancreatic cancer is suspected as a cause of jaundice and/or cholestasis.


1H-NMR spectroscopy of serum in SHN mice with and without spontaneous mammary tumours. Proton nuclear magnetic resonance (1H-NMR) spectra of serum were studied before and after the appearance of spontaneous mammary tumours in intact and anterior pituitary grafted SHN mice. In the sera of non-tumourous animals, the lipid CH2 and CH3 resonances at 1.31 and 0.88 ppm, possibly the peaks of very low density lipoprotein (VLDL), were unclear; however, such resonances were apparently observed in the sera of mammary tumour bearing mice. On the contrary, alanine, beta-hydroxybutyrate, valine and leucine, which peaked clearly in non-tumourous mice, declined greatly in tumourous mice. Livers of tumourous mice were heavier than those of non-tumourous animals. Quite similar trends in serum spectra and liver weight were observed in mice grafted with two anterior pituitaries. These findings indicate that tumour absorption of VLDL increases and other metabolic pathways are largely altered in association with mammary tumour progression. Prolactin, which is essential for mammary tumour development, had little effect on serum spectra of mice either with or without mammary tumours.


Regulation of solute and water balance and cell volume in the central nervous system. The mammalian brain is composed of four distinct fluid compartments: blood, cerebral spinal fluid, interstitial fluid surrounding glial cells and neurons, and intracellular fluid. Maintenance of the ionic and osmotic composition and volume of these fluids is crucial for the normal functioning of the brain. Small changes in intracellular or extracellular solute composition can dramatically alter neuronal signaling and information processing. Because of the rigid confines of the skull and complex brain architecture, changes in total brain volume can cause devastating neurological damage. As a result, it is not surprising to find that the composition and volume of brain intracellular and extracellular fluids are controlled tightly under both normal conditions and in various disease states. Osmotic and ionic balance in the central nervous system is regulated by solute and water transport across the blood-brain barrier, the choroid plexus, and the plasma membrane of glial cells and neurons. Despite its clinical and physiological significance, however, little is known about the underlying cellular and molecular mechanisms by which the central nervous system's osmotic and ionic balance is maintained. In this review, the current understanding of osmoregulation in the mammalian brain and its role in various disease processes such as hyponatremia, renal failure, and hypernatremia will be summarized. A detailed understanding of brain osmoregulatory processes represents a fundamental physiological problem and is required for the treatment of numerous disease states, particularly those encountered in the practice of nephrology.


Thrombotic microangiopathy: a case report and review of the literature. Thrombotic microangiopathy most likely represents a spectrum of diseases consisting of multiple etiologies that has a final common pathway of multiorgan microvascular thrombosis. The variable responses to several different modes of therapy would suggest that more than one pathogenetic mechanism is involved. Untreated, it has been associated with very high morbidity and mortality rates. A poor understanding of the basic disease process has prevented specific treatment modalities, although early diagnosis and availability of dialysis and blood product transfusion services remain crucial. Several modes of therapy have been used to date, with plasma exchange being the most effective method studied and shown to improve survival. On the basis of current knowledge, this form of treatment should be instituted promptly in severe cases. Anecdotal reports of recovery with vincristine or IgG alone or with the use of IgG after the apparent failure of plasma therapy appear promising and deserve further investigation as initial therapeutic measures used in thrombotic microangiopathy. Although the majority of patients recover with normal renal function, those with severe thrombotic microangiopathy may heal through sclerosis with residual hypertension and chronic renal impairment requiring continual medical therapy.


Cell proliferation of the normal esophagus of mice harbouring a squamous cell neoplasia in the uterine cervix. Some human tumors have been found to induce proliferative lesions in the squamous epithelium in organs remote from the primary tumor. This phenomenon was explored in the present animal model. After a single injection of 3H-thymidine, the proportion of DNA synthesizing basal and parabasal esophageal cells as well as the pace of intraepithelial cell migration was assessed in 124 C57Bl mice. The uterine cervix of 57 animals had been painted topically with 3,4 benzo(a)pyrene for 5 months, or with the vehicle acetone (44 animals), while 23 animals remained untreated. Groups of animals were killed from 8 hours to 10 days following a single pulse labelling. The proportion of DNA synthesizing basal and parabasal esophageal cells and of their daughter cells (as deduced by observations at various time intervals) was similar in animals harbouring neoplasias of the uterine cervix, in those treated with benzo(a)pyrene but having histologically normal cervical epithelium, in acetone treated as well as in untreated controls. Thus, in the model used herein, we failed to demonstrate increased cell proliferation in the esophageal mucosa of animals having a squamous cell neoplasia in the uterine cervix. The method appears, however, sensitive enough to register ongoing cell proliferation patterns and will be applied to the study of other experimentally induced tumors.


Diminished acetylcholine-induced vasodilation in renal microvessels of cyclosporine-treated rats. The mechanisms mediating cyclosporin A (CsA)-induced nephrotoxicity have not been established, but damage to endothelial cells by CsA has been proposed as an important factor. In the study presented here, whether endothelial cell function is impaired in the renal vasculature of CsA-treated rats is investigated. The vasodilatory effects of acetylcholine (ACH) on norepinephrine (NE)-induced microvascular constriction in isolated perfused hydronephrotic rat kidneys pretreated with CsA were therefore examined. Hydronephrosis was established to permit direct visualization of renal microvessels. Nephrotoxicity was induced by s.c. injection of CsA (60 mg/kg/day for 5 days). NE (0.3 microM)-induced afferent arteriolar (AA) constriction was exaggerated in CsA rats as compared with that in vehicle (olive oil)-treated control rats. (reduction in diameter of -34 +/- 3 (SE) versus -26 +/- 2%; P less than 0.05). Similarly, efferent arteriolar (EA) constriction by NE in CsA rats exceeded that of controls (-34 +/- 2 versus -22 +/- 3%; P less than 0.01). The vasodilatory responses evoked by ACH were blunted in CsA rats. The AA response to ACH in CsA rats was significantly decreased (P less than 0.005) at ACH concentrations from 1 nM to 1 microM. Similarly, ACH (1 nM to 100 nM) induced less EA vasodilation in CsA rats (P less than 0.025). In control and CsA rats, the addition of nitro-L-arginine abolished AA and EA vasodilation induced by ACH, suggesting that the sustained vasodilatory responses of AA and EA to ACH are mainly dependent on nitric oxide synthesis.(ABSTRACT TRUNCATED AT 250 WORDS)


Effect of cyclosporine on endothelial albumin leakage in rats. Short-term treatment of rats with cyclosporine (cyclosporine A [CsA]; Sandimmune) results in a marked reduction in intravascular plasma volume, a factor that might contribute to the renal dysfunction associated with this potent immunosuppressant. To examine the role of plasma extravasation in CsA-induced hypovolemia, intravascular plasma volumes (PV), blood volumes, [125I]albumin disappearance, and changes in hematocrit (Hct) were measured in Inactin-anesthetized rats subjected to minimal surgery. The rats were treated for 3 wk with either 25 mg/kg/day of CsA s.c. or vehicle. Plasma creatinine and urea were significantly elevated, and magnesium was reduced in the CsA group (N = 6) as compared with controls (CON) (N = 6). CsA treatment had no effect on urinary protein and albumin excretion. Blood volume was significantly lower in CsA than in CON (8.4 +/- 0.5 versus 10.6 +/- 0.3 mL/100 g body wt) as was PV (4.3 +/- 0.2 versus 5.5 +/- 0.2 mL/100 g body wt). Two hours after injection, plasma [125I]albumin concentration had fallen by 41 +/- 4% in CsA versus 23 +/- 5% in CON. Because Hct, and, hence PV, was unchanged in both groups during these 2 h, these data indicate enhanced endothelial albumin leakage in the CsA group. In two additional groups of six rats each, acute volume expansion with fresh whole blood (2 mL/100 g body wt) resulted in extravasation of plasma. Hct rose by 8.0 +/- 0.2% in CsA versus 3.8 +/- 0.2% in CON after 150 min, corresponding to 27 +/- 3 and 15 +/- 2% decreases in total PV, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)


Radiocontrast agents induce endothelin release in vivo and in vitro. The intravascular administration of the ionic radiocontrast agent sodium iothalamate (2.9 g of iodine/kg body wt) to rats induced an increase in plasma concentration of immunoreactive endothelin from 21.3 +/- 1.2 to 36 +/- 3 fmol/mL, preceded by a transient rise in the plasma level of atrial natriuretic peptide and associated with a fall in RBF. Equi-iodine amounts of the nonionic agents ioxaglate and iohexol elicited similar or more marked changes in plasma endothelin, but hypertonic solutions of NaCl, mannitol, or glucose did not. Comparable levels of endothelin produced by infusions of endothelin-1 induced a reduction of up to 29% in RBF. Iothalamate and iohexol stimulated endothelin release from cultured bovine endothelial cells, suggesting a direct effect of ionic and nonionic agents on vascular endothelium. The data invite speculation that under some circumstances endothelin release might play a role in the circulatory changes caused by these compounds and in the pathogenesis of radiocontrast nephropathy.


Genetic heterogeneity and differences in glomerular hemodynamics between inbred colonies of Munich-Wistar rats. DNA fingerprint analysis and renal micropuncture studies were performed in Munich-Wistar rats purchased from Harlan Industries and Simonsen Laboratories to determine whether these rats are genetically heterogeneous and exhibit differences in glomerular hemodynamics. RBF and GFR were similar in rats from both colonies. Glomerular capillary pressure was lower in rats from the Harlan colony (46 +/- 2 mm Hg) than in those from the Simonsen colony (56 +/- 2 mm Hg). The low glomerular capillary pressure in the Harlan rats was primarily due to a lower postglomerular vascular resistance. The estimated whole-kidney ultrafiltration coefficient (Kf) was significantly greater in the rats obtained from the Harlan colony than in those obtained from the Simonsen colony (0.12 +/- 0.03 versus 0.05 +/- 0.01 mL/min/g kidney wt/mm Hg). The DNA fingerprints of the Simonsen rats were different from those of the Harlan rats. These results provide evidence of physiologic and genetic heterogeneity between commercially available inbred strains of Munich-Wistar rats in the United States and suggest that comparison of results with Munich-Wistar rats from different sources may be more difficult than previously recognized.


Captopril and tubuloglomerular feedback in remnant kidneys of prehypertensive rats. The activity and characteristics of tubuloglomerular feedback (TGF) are altered subsequent to reductions in renal mass or blockade of the renin-angiotensin system. This study assessed the combined effects of renal ablation and captopril on TGF. Renal mass was reduced in male Sprague-Dawley rats by the surgical removal of 1 1/2 kidneys. At 2 and 8 wk postsurgery, TGF was studied by micropuncture before and after the administration of captopril (0.5 mg/kg i.v.) Before captopril, TGF in remnant kidneys (NX) was characterized by a higher tubular perfusion rate required for a 50% maximal response (TGF turning point) as compared with intact kidneys of controls (CNT) at both 2 (NX, 35 +/- 3; CNT, = 19 +/- 1 nL/min; P less than 0.05) and 8 wk (NX, 54 +/- 5; CNT, 20 +/- 1 nL/min; P less than 0.05). Captopril significantly increased the turning point in both intact and remnant kidneys at both 2 (NX, 43 +/- 2; CNT, 25 +/- 2 nL/min) and 8 wk (NX, 61 +/- 5; CNT, 28 +/- 2 nL/min) postsurgery. Captopril also significantly reduced the maximal TGF response in both intact and remnant kidneys at 2 (NX from 13 +/- 3 to 7 +/- 1 mm Hg; CNT from 10 +/- 1 to 5 +/- 1 mm Hg) and 8 wk (NX from 15 +/- 1 to 9 +/- 2 mm Hg; CNT from 13 +/- 1 to 7 +/- 1 mm Hg).(ABSTRACT TRUNCATED AT 250 WORDS)


Saccular intracranial aneurysms in autosomal dominant polycystic kidney disease. The literature on the association of intracranial aneurysms in autosomal dominant polycystic kidney disease (ADPKD) consists mainly of case reports and small series of patients. To provide a more-detailed description of this association and its frequency, the records of all ADPKD patients with saccular intracranial aneurysms, all ADPKD autopsy cases including brain examination, and sex- and age-matched autopsy cases without ADPKD seen at the Mayo Clinic between 1950 and 1989 and of all Rochester residents with a diagnosis of subarachnoid hemorrhage or ADPKD between 1945 and 1984 were reviewed. The presentation of the 41 patients (22 men and 19 women; mean age, 46.4 yr) with this association was subarachnoid hemorrhage in 33, transient ischemic attacks in 2, incidental angiographic or autopsy finding in 5, and discovery during angiographic screening in 1. Thirty-one, seven, and three patients harbored one, two, and three aneurysms, respectively, arising from the middle cerebral artery (N = 23), anterior communicating artery (N = 16), internal carotid artery (N = 11), and vertebral or basilar artery (N = 4). A family history of intracranial aneurysm, subarachnoid hemorrhage, or intracranial hemorrhage at an early age was present in 22% of the patients. Small aneurysms (less than 5 mm) were less likely to have ruptured or caused symptoms (P less than 0.04). There was a trend for hypertension to be associated with the severity of the subarachnoid hemorrhage. Aneurysmal rupture occurred before age 50 in 64% of patients. Of the 89 ADPKD autopsy cases with brain examination, 22.5% had intracranial aneurysms.(ABSTRACT TRUNCATED AT 250 WORDS)


Calcium acetate as a phosphorus binder in hemodialysis patients. Much interest is currently centered on the use of calcium acetate as a phosphorus binder in patients with renal failure. Therefore, this compound in subjects previously stable on calcium carbonate and undergoing high-efficiency hemodialysis with a dialysate calcium of 2.5 mEq/L was evaluated. Twenty subjects were switched from generic calcium carbonate to a single calcium carbonate preparation for a period of 2 months. This was followed by a phase (1 month) in which calcium acetate was substituted for calcium carbonate at a dose containing half the amount of elemental calcium. Subjects then continued calcium acetate for 6 months. It was found that calcium acetate allowed comparable control of immunoreactive parathyroid hormone, calcium, and phosphorus levels compared with calcium carbonate. This occurred with half the amount of elemental calcium ingested in the form of calcium acetate (349 +/- 25 versus 699 +/- 75 mmol/day; P less than 0.001). With this lower dose, the overall incidence of hypercalcemia was the same with each formulation. In the eight subjects concurrently receiving i.v. calcitriol, the incidence of hypercalcemia was significantly higher during the first month of calcium acetate compared with that in those not receiving this compound (P less than 0.05). Of those four subjects receiving the high dose of calcitriol (2 micrograms thrice weekly), all required either reduction in the dose or discontinuation of the drug. Thus, mineral metabolism could be controlled adequately with calcium acetate despite using half as much elemental calcium compared with calcium carbonate. This, however, did not result in a lower incidence of hypercalcemia, particularly in those receiving i.v. calcitriol.


How tonicity regulates gene expression.

How tonicity regulates gene expression. The expression of a number of different mammalian genes is directly affected by hypertonicity. At present, the list of their products includes aldose reductase, heat shock proteins, early response factors, and transporters for betaine, inositol, and taurine. Hypertonicity increases the abundance of the mRNAs for all of them. Aldose reductase mRNA levels increase because of increased transcription with little change in the stability of its mRNA. Transcription of the betaine transporter also increases. The mechanisms by which hypertonicity increases the transcription of these mammalian genes remain speculative. However, the consideration of transcriptional control of betaine transport in bacteria and of heat shock proteins in many organisms provides interesting insight into this question.


Phospholipase A2 and signal transduction. Phospholipases A2 (PLA2) comprise a family of enzymes that hydrolyze the acyl bond at the sn-2 position of phospholipids to generate free fatty acids and lysophospholipids. Different forms of PLA2 are involved in digestion, inflammation, and intercellular and intracellular signal transduction. The sn-2 position of phospholipids in mammalian cells is enriched in arachidonic acid, the precursor of eicosanoids, which have diverse physiologic and pathophysiologic effects on the kidney and other organs. Thus, the regulation of PLA2 activity has important implications for kidney function. PLA2 regulation involves: calcium, pH, protein kinases, GTP-binding proteins, inhibitory and activating proteins, metabolic product inhibition, and transcriptional control. The various roles of arachidonic acid and cyclooxygenase, lipoxygenase, and cytochrome P450 mono-oxygenase products of arachidonic acid metabolism, as intracellular messengers, in the regulation of membrane channel activities, intracellular enzyme activities, cellular calcium homeostasis, mitogenesis, differentiation, cytokine and early response gene expression are discussed.


Growth hormone and the kidney: a case presentation and review of the literature. Hypersomatotropism is accompanied by a significant increase in GFR and RPF. A case of a patient with acromegaly and supranormal renal function as measured by inulin and p-aminohippurate clearances is reported. The literature regarding the effects of growth hormone on renal function is reviewed, and the potential mechanisms of action and therapeutic implications of these effects are discussed.


Effect of erythropoietin on hematocrit and blood pressure in normotensive and hypertensive rats. Treatment with recombinant human erythropoietin (rHuEPO) successfully reverses anemia in uremic patients. Of major concern, however, are blood pressure (BP) increases during rHuEPO therapy, observed particularly in persons with a history of hypertension. To determine whether preexisting hypertension enhances BP increases to rHuEPO, BP responses to 2 wk of rHuEPO or placebo were observed in spontaneously hypertensive rats (SHR) and their normotensive genetic controls (Wistar-Kyoto [WKY] rats. In addition, the role of endothelial-released nitric oxide (NO) in BP alterations caused by rHuEPO through i.v. infusions of endothelium-dependent and independent vasoactive agents were indirectly examined. At trial completion, rHuEPO elevated hematocrit, hemoglobin, and mean cell volume more in SHR than in WKY rats (P less than 0.001). Despite the considerable increase in hematocrit, rHuEPO did not alter BP in either strain. An infusion of NG-monomethyl-L-arginine (L-NMMA), a specific inhibitor of NO formation, elevated BP more in rHuEPO-treated SHR than in identically treated WKY rats (P less than 0.05). Further, the administration of L-arginine caused a greater decrease in blood pressure in SHR than in WKY rats, independent of treatment condition (P less than 0.01). Because changes in BP with endothelium-independent agents were similar across groups, responses to L-NMMA and L-arginine were specific to the endothelium and probably independent of basal BP. Thus, rHuEPO provoked greater erythropoiesis in SHR than in WKY rats but did not elevate BP. L-NMMA stimulated higher BP in SHR treated with rHuEPO, suggesting a compensatory increase in vasodilatory NO synthesis to protect against a hypertensive effect of the drug in SHR.(ABSTRACT TRUNCATED AT 250 WORDS)


Effect of dietary potassium chloride in borderline hypertensive rats. The borderline hypertensive rat is the first filial offspring of the spontaneously hypertensive rat and the Wistar-Kyoto rat. With increased dietary sodium chloride intake, the borderline hypertensive rat develops hypertension and exaggerated cardiovascular and renal responses to acute environmental stress, similar to those observed in the hypertensive spontaneously hypertensive rat parent. In other models of sodium chloride-sensitive hypertension with different genetic background (Dahl rat), dietary potassium chloride supplementation protects against the development of hypertension, increased sympathetic nervous system activity, and exaggerated responses to acute environmental stress. This investigation sought to determine whether the dietary sodium chloride-induced development of both the hypertension and the exaggerated responses to acute environmental stress could be reversed or prevented by increased dietary potassium chloride intake. Dietary potassium chloride intake was increased with a 1% potassium chloride drinking solution either after 12 wk of 8% sodium chloride intake (reversal) or concomitant with the onset of 12 wk of 8% sodium chloride intake (prevention). An increase in dietary potassium chloride intake did not reverse or prevent the development of either the hypertension or the exaggerated cardiovascular and renal responses to acute environmental stress in borderline hypertensive rats fed 8% sodium chloride. It is concluded that the difference in genetic background between borderline hypertensive rats and other models of sodium chloride-sensitive hypertension is an important determinant of the protective effect of dietary potassium chloride supplementation.


Endothelin in a model of acute ischemic renal dysfunction: modulating action of atrial natriuretic factor. This study was undertaken to investigate circulating endothelin (ET) and associated renal hemodynamics in the acute ischemic renal dysfunction associated with suprarenal aortic cross-clamping (ACC) in the presence and absence of prostaglandin inhibition in the anesthetized dog. Second, the modulating action of exogenous atrial natriuretic factor (ANF) was also investigated. In Group I (ACC; N = 6), ACC was performed in the absence of prostaglandin inhibition. No change in mean arterial pressure, GFR, RBF, renal vascular resistance, or ET was noted 2 h after reperfusion when compared with baseline values. In the presence of prostaglandin inhibition with indomethacin (10 mg/kg iv) (Group II, ACC + INDO; N = 10), an increase in plasma ET was first noted to be elevated above baseline ET in Group I as well as during and 2 h after ACC in association with a reduction in GFR, marked renal vasoconstriction, and a sustained increase in arterial pressure. To evaluate the role of the kidney in this increase in ET, another group (Group III, ACC + INDO + NEPH; N = 6) was investigated in the presence of prostaglandin inhibition, and bilateral renal artery clamping was performed 30 min before ACC and maintained throughout the protocol to simulate nephrectomy. In this group, plasma ET concentrations did not increase during ACC. Because ANF may antagonize the renal actions of ET in vivo and may suppress ET release in vitro, the action of ANF upon GFR and plasma ET was evaluated in Group IV (ACC + INDO + ANF; N = 6).(ABSTRACT TRUNCATED AT 250 WORDS)


Interleukin-1-induced alterations in glomerular proteoglycans: biochemical and tissue autoradiographic aspects. The effect of interleukin-1 alpha (IL-1) on the synthesis of glomerular basement membrane heparan sulfate-proteoglycan (HS-PG) was investigated. An ex vivo recirculating organ perfusion system was used. Kidneys were perfused with a medium containing (35S) sulfate and IL-1 (0.625 to 6.25 ng/mL). After radiolabeling was performed, a small cortical piece was saved for tissue autoradiography; the remaining kidney and perfusion medium were used for biochemical studies. Renal cortices were dissected out, and glomeruli were isolated; the PG were extracted and characterized. With exposure to IL-1 (5 ng/mL), an approximately twofold increase of the radioactivity in the glomerular fraction was noted. The increase was unaffected by indomethacin treatment. By Sepharose CL-6B chromatography, a single peak of radioactivity with Kav = 0.25 (macromolecular form of PG) was observed in the control group. The IL-treated group had two peaks of radioactivity with Kav = 0.25 and 0.45: the first peak contained PG, and the second peak consisted of free glycosaminoglycan (GAG) chains. Elution profiles of hydrolyzed tissue GAG chains were similar. No change in the ratio of chondroitin to heparan sulfate was observed. By DEAE-Sephacel chromatography, the glomerular PG/GAG of the IL-treated group eluted at a relatively lower salt concentration, suggesting a change in the charge density characteristics. No differences in the elution profiles of media PG/GAG were observed. (35S)methionine labeling of proteins showed no significant increase of the total radioincorporation in the IL-treated group. Immunoprecipitation studies revealed an approximately 88% increase in the de novo synthesis of PG. Tissue autoradiography revealed an approximately twofold increase of (35S) sulfate radioactivity over the glomerular mesangium, epithelium, and basement membranes. These results indicate that IL-1 enhances the synthesis of the macromolecular form of PG and the generation of free chains. Conceivably, such alterations may lead to defective macromolecular interactions among various components of the glomerular basement membrane and compromise the integrity of the ultrafiltration unit of the glomerulus.


Large glomerular size in Pima Indians: lack of change with diabetic nephropathy. The mean glomerular volume, glomerular fraction of cortical volume, and percentage of obsolescent glomeruli were calculated in kidney specimens from autopsies on 34 Pima Indians, of whom 15 had non-insulin dependent diabetes mellitus and kidney disease of diabetes mellitus. These values were compared with those of black, white, and non-Pima native American individuals without diabetes mellitus. Glomerular volume in the Pima Indians was similar in the diabetic and nondiabetic subjects and significantly greater than in the white subjects. Black and non-Pima native American individuals had glomerular volumes intermediate between white individuals and Pima Indians. The mean glomerular volume was not affected by the number of obsolescent glomeruli in diabetic Pima Indians. The glomerular volume fraction was greater in the Pimas than in the other groups. These data showed that glomerular volume in the Pima Indians was significantly greater than that in white subjects. There was no difference between diabetic and nondiabetics Pimas, and glomerular size was not correlated with the presence or degree of glomerulosclerosis in this population.


Severe hypercholesterolemia inhibits cyclosporin A efficacy in a dose-dependent manner in children with nephrotic syndrome. In order to identify possible markers of cyclosporin A (CSA) efficacy, the use of CSA (6 mg/kg) in 47 children with refractory nephrotic syndrome was reviewed. Response was defined as remission of proteinuria within 2 months. Before CSA administration, nonresponders (N = 13) were found to have more proteinuria (6 versus 3 g/24 h; P less than 0.03) and higher serum creatinine levels (0.9 versus 0.6 mg/dL; P less than 0.03) compared with responders (N = 34). Also, a markedly elevated serum cholesterol level (545 versus 312 mg/dL; P less than 0.001) was noted among nonresponders. Logistic regression analysis of all three parameters isolated serum cholesterol (P less than 0.01) as the only significant predictor of CSA nonresponsiveness. Discriminate analysis identified serum cholesterol to predict 97% of responders and 77% of nonresponders (P less than 0.0005) to conventional CSA doses. The CSA whole-blood trough HPLC levels were subtherapeutic among nonresponders (71 ng/mL) compared with responders (162 ng/mL) (P less than 0.001). Thus, a high serum cholesterol level may prevent the achievement of therapeutic CSA blood levels with conventional doses. On the basis of this, seven of the nonresponders were re-treated by titration of the CSA dose (10 to 14 mg/kg) with their serum cholesterol level. Their mean highest trough CSA level was 286 ng/mL. Five patients responded within 2 months. No elevation in serum creatinine or evidence of nephrotoxicity on repeat biopsy was seen after 2 months of therapy in all seven patients. It was concluded that severe hypercholesterolemia in nephrotic syndrome patients necessitates the titration of the CSA dose with the serum cholesterol level to achieve remission.


Congenital nephrotic syndrome: preemptive bilateral nephrectomy and dialysis before renal transplantation. Congenital nephrotic syndrome (CNS) is a rare and uniformly fatal disease if it is not treated. Although renal transplantation has been a successful treatment, there remains a high mortality rate during the first year of life before transplantation. From 1979 to 1987, four patients with CNS, all of whom died before they could undergo renal transplantation were treated. On the basis of this clinical experience, early elective bilateral nephrectomy and dialysis for infants with CNS were initiated to improve overall outcome. From 1987 to 1989, this protocol has been used on four consecutive patients with CNS. In these patients, bilateral nephrectomy was performed only after patients suffered a serious CNS-related complication that occurred between 4 and 6 months of age. Despite nephrectomy and the need for chronic dialysis, all patients grew at normal or accelerated rates. By 16 months of age, all patients underwent successful renal transplantation.


Absence of H(+)-ATPase in cortical collecting tubules of a patient with Sjogren's syndrome and distal renal tubular acidosis. Distal urinary acidification abnormalities may arise from transepithelial voltage defects, permeability defects, or proton-secretory defects, but tests to determine the cellular mechanisms underlying secretory abnormalities have not previously been reported. A patient with Sjogren's syndrome and distal renal tubular acidosis due to a secretory defect is described, whose kidney biopsy was examined by fluorescent immunocytochemistry with an antibody to the M(r) 31,000 subunit of the mammalian kidney vacuolar H(+)-ATPase and was compared with normal human kidney. Staining with the anti-H(+)-ATPase antibody in normal human kidney was detected in the brush border microvilli and subvillar invaginations of the proximal tubule and in intercalated cells in the collecting duct. A biopsy sample from the patient was devoid of any anti-H+-ATPase staining in the intercalated cells. Staining was also absent from the proximal tubule brush border microvilli but was present in the subvillar invaginations. Although autoantibodies to normal human kidney membrane proteins were detected in the serum by immunoblot analysis, no immunocytochemical evidence for anti-intercalated cell autoantibodies was observed in the patient's serum. This report demonstrates that the basis for the proton secretory defect in some patients with distal renal tubular acidosis is likely the absence of H(+)-ATPase in the intercalated cells. It also illustrates the potential diagnostic utility of anti-H(+)-ATPase antibodies in the classification of distal renal tubular acidoses.


Effects of alpha 1 and beta-adrenergic antagonists and 5-hydroxytryptamine receptor antagonist on portal-systemic collateral vascular resistance in conscious rats with portal hypertension. In order to study the acute effects of pharmacological agents on the vascular resistance of portal-systemic collaterals, a model of total portal vein occlusion with 100% portal-systemic shunts was developed in the conscious rat. The haemodynamic effects of several vaso-active substances were evaluated in this model and compared with those obtained after saline administration. Prazosin (0.5 mg), an alpha 1-adrenergic antagonist, significantly reduced mean arterial pressure by 29%, portal pressure from 13.8 +/- 1.0(mean +/- s.e.m.) to 10.1 +/- 0.4 mmHg and portal tributary blood flow (radioactive microspheres) from 13.6 +/- 2.1 to 11.7 +/- 1.2 mL/min. It also decreased portal-systemic vascular resistance from 95 +/- 16 to 73 +/- 9 dyn s/cm5 x 10(3). Propranolol (4 mg), a beta-adrenergic antagonist, significantly reduced mean arterial pressure by 12% and portal pressure from 15.5 +/- 1.2 to 13.3 +/- 0.9 mmHg while reducing portal tributary blood flow from 14.6 +/- 1.5 to 11.0 +/- 1.7 mL/min and increasing portal systemic collateral vascular resistance from 88 +/- 7 to 103 +/- 8 dyn s/cm5 x 10(3). Ketanserin (0.25 mg/kg), a 5-hydroxytryptamine receptor antagonist, reduced portal pressure from 15.8 +/- 1.0 to 13.3 +/- 0.7 mmHg at a dose that did not alter mean arterial pressure or portal tributary blood flow. It achieved this by reducing portal-systemic collateral vascular resistance from 90 +/- 14 to 74 +/- 13 dyn s/cm5 x 10(3). Saline had no significant effect on systemic and splanchnic haemodynamics. This study shows that ketanserin decreases vascular resistance of portal-systemic collaterals while propranolol increases it. Thus, it is suggested that collateral vascular resistance is accessible to pharmacological manipulation.


Hypoechoic lesions in the 'bright liver': a reliable indicator of fatty change. A prospective study. The accuracy of ultrasonographic diagnosis of hypoechoic focal fatty change in the 'bright liver' was evaluated in 40 lesions found in 35 patients followed up for a mean period of 37.8 months. Patients with ultrasound and laboratory findings suggesting liver cirrhosis were excluded from the study. All patients underwent a blind liver biopsy in order to verify the diagnosis of diffuse disease suggested by the finding of 'bright liver'. No guided biopsy was performed on the focal lesions in order to establish the accuracy of ultrasound alone in recognizing focal fatty change. Clinical, haematologic and echographic follow-up confirmed the diagnosis in all cases. All histological specimens revealed liver steatosis, indicating a 100% sensitivity of ultrasonography in identifying non-cirrhotic fatty liver with an accompanying focal change. Increased echogenicity and hypoechoic focal changes are reliable indicators of fatty infiltration, making ultrasonography an acceptable, non-invasive method for the diagnosis of liver steatosis.


Mutation of the core region of HBV-DNA and submassive hepatic necrosis in patients with anti-HBe-positive chronic hepatitis B. Three patients with submassive hepatic necrosis developed acute liver failure during the severe reactivation of chronic hepatitis B. The activity of hepatitis B virus (HBV) DNA polymerase increased in all three patients immediately before the onset of hepatic failure. Liver biopsy specimens obtained before and after the episode of submassive hepatic necrosis showed progression to advanced liver cirrhosis. The nucleotide sequences of the precore and core regions of HBV-DNA were investigated in two of the three patients and in another two patients with piecemeal and bridging necrosis. The nucleotide and amino acid sequences of the HBV-DNA core region changed after reactivation in the the two patients with submassive hepatic necrosis, while the sequences in the other two patients with piecemeal necrosis remained unchanged before and after reactivation. These results suggest that the antigenicity of the HBV-DNA core region may have been changed before and after severe reactivation. Due to mutation at the core region, a different type of epitope would be expressed on the hepatocytes after submassive hepatic necrosis, which would not be a target for the cytotoxic T cell. This was evident by the continuation of the normal serum GPT for 5 and 9 years, respectively.


Role of endogenous platelet-activating factor (PAF) in endotoxin-induced portal hypertension in rats. To determine the role of platelet-activating factor (PAF) in endotoxin-induced portal hypertension, we performed continuous recording of both blood pressure (BP) and portal venous pressure (PVP) in rats following the administration of intravenous PAF (25 ng/kg), intraportal PAF (25 ng/kg), intraportal endotoxin (2 mg/kg), and intraportal endotoxin (2 mg/kg) for 1 min subsequent to pretreatment with a specific PAF-antagonist (CV-6209, 1 mg/kg, i.v.). Basal resting values of both BP (102.3 +/- 9.3 mmHg) and PVP (7.7 +/- 1.2 mmHg) fell rapidly after intravenous infusion of PAF (BP: 36.7 +/- 5.8 mmHg; PVP: 5.7 +/- 0.8 mmHg) and followed by gradual return. Intraportal PAF infusion elicited a rapid but less severe depression of BP (57.2 +/- 9.4 mmHg) as compared with intravenous PAF infusion, whereas PVP was increased transiently around 4 min after treatment (11.0 +/- 5.3 mmHg). A similar degree of PVP elevation (10.7 +/- 2.0 mmHg) was observed between 8 and 20 min after intraportal administration of endotoxin. Depression of BP was initiated 12 min after endotoxin administration but was not severe (76.6 +/- 12.8 mmHg). CV-6209 significantly alleviated the endotoxin-induced elevation of PVP and completely inhibited the hypotension. These observations suggest that: (i) PAF-induced elevation of PVP is a direct response of the liver to PAF; and (ii) endogenous PAF plays an important role in the endotoxin-induced portal hypertension.


Three-dimensional ultrastructure of normal rat hepatocytes by quick-freezing and deep-etching method. The three-dimensional ultrastructure of nuclei and cell organelles including rough-surfaced endoplasmic reticulum (RER), mitochondria, and cytoskeleton were studied in normal rat hepatocytes by the quick-freezing and deep-etching method. Peroxisomes and mitochondria were observed as spherical structures with granular matrices. Peroxisomes were identified by their size and matrices, which were more condensed than those of mitochondria. Ribosomes were identified as granular structures and were attached to the surface of endoplasmic reticulum. Cytoskeletal filaments were identified by their differences in diameter on the replica membranes, as well as in conventional ultrathin sections. Microfilaments were mainly localized around the bile canaliculi and adjacent to sinusoids. Intermediate filaments were observed around the bile canalicular microfilaments. Only a few filaments were observed near the lateral plasma membranes. Cross-bridges measuring 5-7 nm in diameter were localized between the lamellae of RER and the surface of mitochondria. The quick-freezing and deep-etching method could be used to clarify the three-dimensional association between the cytoskeleton and membrane-bound organelles in hepatocytes.


Effect of naloxone on the haemodynamics and the outcome of experimental acute pancreatitis in dogs. Endogenous opioid peptides may play a role in the genesis of pancreatic damage in acute pancreatitis. The effects of naloxone on the haemodynamic changes in acute pancreatitis were investigated by inducing it in dogs with pancreatic ductal injection of fresh trypsin-bile mixture. In the control group (n = 8), acute pancreatitis was characterized haemodynamically by falls in the maximum positive and negative dP/dt (+/- dP/dt), cardiac output (CO) and cardiac index (CI), and increases in the pulmonary vascular resistance (PVR) and systemic vascular resistance (SVR) as well as an early reduction of pancreatic blood flow (PBF). In another set of eight dogs (naloxone group), naloxone was given intravenously 10 min after the induction of acute pancreatitis (80 micrograms/kg as a bolus + 80 micrograms/kg/h for 3 h). Compared with untreated dogs, naloxone significantly increased PBF and the +/- dP/dtmax; prevented the significant decreases in CO and CI and increases in PVR and SVR, and reduced significantly the severity of pancreatitis, as assessed by both the histological staging and the mortality rate. These results suggest that naloxone limits the progression of acute pancreatitis from oedematous to haemorrhagic form. It is proposed that endogenous opioid peptides may play a role in the pathophysiology of acute pancreatitis.


Protective effect of SR 27417, a novel PAF antagonist, on PAF- or endotoxin-induced hypotension in the rat and the guinea-pig. SR 27417, the first member of a newly-developed PAF antagonist series, inhibited in a dose-dependent manner the hypotensive effect of PAF in rats. It protected rats with an ED50 = 6 micrograms/kg, when given i.v., 1 min before PAF or p.o. (ED50 = 170 micrograms/kg) 1 h before PAF administration. After i.v. or oral administration, SR 27417 (1 and 3 mg/kg, respectively) exhibited extended duration of action (between 48 and 72 h). Similarly, i.v. administration of 1 to 6 mg/kg of SR 27417 afforded complete protection of guinea-pigs against endotoxin-induced hypotension but also totally reversed established endotoxin-induced hypotension. These results therefore confirm that PAF plays a major role in septic shock and that SR 27417 may be an effective prophylactic as well as a potent curative drug.


Production and characterization of antibodies to platelet-activating factor. Antibodies directed against platelet-activating factor (PAF) have been raised in rabbits immunized with a novel platelet-activating factor analogue-conjugate. An analogue of PAF with a carbon double bond at the terminal end of the alkyl chain was subjected to ozonolysis and converted to the aldehyde. The aldehyde was coupled to thyroglobulin by reductive alkylation and rabbits were immunized via either intramuscular or intradermal routes in complete Freund's adjuvant. The antibodies are specific for PAF with a preference for the optically active (R)-enantiomer. There appears to be a requirement for antibody binding of an alkyl chain of up to 18 Carbon atoms at C1, and an acetyl group in the C2 position. The ability of a number of structural analogues to inhibit binding of tracer to the antibody is related to the biological activity of the analogue, and therefore may reflect the structural domains that are critical for PAF to interact with its receptor.


Perforated peptic ulcer in Hong Kong and New South Wales. Direct comparisons of ulcer perforation rates and trends between countries have not been made in the past. Data on hospital admissions for perforated peptic ulcer during 1 January 1979 to 31 December 1985 were collected in Hong Kong (5868 perforations) and New South Wales, Australia (1669 perforations). Age and sex specific rates per 100,000 population were calculated. In Hong Kong, annual duodenal ulcer and gastric ulcer perforation rates were 13-16 and under two per 100,000 population respectively. In New South Wales, the corresponding rates were between three and four and under two per 100,000 population, respectively. The male:female ratios for duodenal ulcer perforation were consistently about 5:1 in Hong Kong and 2:1 in New South Wales, and for gastric ulcer perforation about 2:1 and 1:1, respectively. The incidence of perforation increased with age, and there was a statistically significant rise, over time, in duodenal but not gastric ulcer perforation rates in persons aged over 60 years in New South Wales; similar trends were seen in Hong Kong. Thus duodenal ulcer perforation occurs five times more commonly in Hong Kong than in New South Wales and this is largely accountable for by the higher rates of duodenal ulcer perforation in Chinese than in Australian males. Such geographical differences can best be explained by the occurrence of multiple aetiological mechanisms in ulcer perforation. Furthermore, there appears to be an increased susceptibility and an appreciable rising trend for duodenal ulcer perforation to occur in the elderly.


Long-term follow-up of dilatation treatment of oesophageal strictures. A review of the endoscopy records of 100 consecutive patients with oesophageal strictures was undertaken to determine the effectiveness of endoscopic dilatation therapy. The follow-up period from presentation ranged from 6 to 72 (mean 39 months) and the symptom-free period after the last dilatation ranged from 3 to 66 months (mean 29 months). Three hundred and fifty procedures were performed with no perforations and minimal morbidity. Eighty-one patients who had been followed for at least 12 months since their last dilatation were free of significant dysphagia. Of these 81 patients, 77% became symptom-free within 1 year, and 88% within 2 years. Only 35 patients required more than three dilatations; 30 patients required one dilatation and 35 required two to three dilatations. Age, sex, the presence of Barrett's oesophagus, or the oesophageal lumen diameter at presentation was not significantly correlated with outcome.


Correlation between CA19-9 production in vitro and histological grades of differentiation in vivo in clones isolated from a human pancreatic cancer cell line (SUIT-2). The production of carcino-embryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) were investigated in 28 clones isolated from a human pancreatic cancer cell line (SUIT-2) and related to in vitro morphology of the clones and in vivo tumorigenicity. Clones of fusiform and polygonal cells could be morphologically distinguished in confluent cultures. There was no significant difference in CEA production between fusiform-cell clones (2.10 +/- 2.70 ng/L x 10(6) per 24 h) and polygonal-cell clones (6.01 +/- 7.30 ng/L x 10(6) per 24 h), but polygonal-cell clones had higher production of CA19-9 (1176.1 +/- 1628.4 U/L x 10(6) per 24 h) than fusiform (6.0 +/- 7.3 U/L x 10(6) per 24 h; P < 0.01). Production of CA19-9 in vitro correlated with the histological grade of differentiation in vivo in nude mice (r = 0.73, P < 0.001), but CEA production did not. The polygonal-cell clones developed well-differentiated carcinomas in vivo and produced significantly more CA19-9 (P < 0.001) than fusiform-cell clones, which generally developed into poorly differentiated tubular adenocarcinomas in vivo. This cell line may provide an appropriate system for further studies of the biology and therapy of pancreatic cancer.


Binding of platelet-activating factor to oviductal membranes during early pregnancy in the rabbit. The present study explores the ability of rabbit oviductal membranes to bind tritiated platelet-activating factor [3H]PAF on days 3 and 6 of pregnancy. Under optimal conditions (25 degrees C, 120 min) equilibrium saturation analysis revealed only one class of binding sites, characterized by Kd s(nM), 80.03 +/- 11.60 and 11.17 +/- 7.09 and Bmaxs, (pmol/mg protein), 5.25 +/- 2.23 and 1.08 +/- 0.22 (N = 3, mean +/- SEM) for ampullar membranes on days 3 and 6, respectively. The corresponding values for isthmic membranes were Kds, 86.56 +/- 12.01 and 52.43 +/- 30.49 and Bmaxs, 9.41 +/- 0.67 and 2.88 +/- 1.96 for days 3 and 6, respectively. Significant differences between days 3 and 6 were observed only in the binding affinities for the ampullar membranes and the binding capacities for the isthmic binding sites. [3H]PAF binding was inhibited in the following order of decreasing potency: lyso-PAF greater than PAF C18:0 greater than U66985 greater than PAF C16:0 for day 3 ampullar membranes; and lyso-PAF C16:0 greater than PAF C18:0 greater than U66985 greater than PAF C16:0 for day 6 ampullar membranes. These studies show the existence of specific oviductal membrane PAF binding sites, the binding parameters of which may be related to the stage of pregnancy, rather than to the spatial location along the oviduct. The relative proportion of endosalpinx to myosalpinx between the ampulla and isthmus may have masked inherent differences and account for the relatively low affinity binding. The physiological significance of oviductal membrane PAF binding is yet to be established.