Molecular genetic study of the frequency of monosomy 22q11 in DiGeorge syndrome. It is well established that DiGeorge syndrome (DGS) may be associated with monosomy of 22q11-pter. More recently, DNA probes have been used to detect hemizygosity for this region in patients with no visible karyotypic abnormality. However, DGS has also been described in cases where the cytogenetic abnormality does not involve 22q11; for instance, four cases of 10p- have been reported. In this study we have prospectively analyzed patients, by using DNA markers from 22q11, to assess the frequency of 22q11 rearrangements in DGS. Twenty-one of 22 cases had demonstrable hemizygosity for 22q11. Cytogenetic analysis had identified interstitial deletion in 6 of 16 cases tested; in 6 other cases no karyotype was available. When these results are combined with those from our previous studies, 33 of 35 DGS patients had chromosome 22q11 deletions detectable by DNA probes.


Evidence for increased prevalence of SRY mutations in XY females with complete rather than partial gonadal dysgenesis. The Y chromosome gene SRY (sex-determining region, Y gene) has been equated with the mammalian testis-determining factor. The SRY gene of five subjects with 46,XY complete gonadal dysgenesis (46,XY karyotype, completely female external genitalia, normal Müllerian ducts, and streak gonads) was evaluated for possible mutations in the coding region by using both single-strand conformation polymorphism (SSCP) assay and DNA sequencing. Mutations were identified in three subjects, of which two gave altered SSCP patterns. Two of them were point mutations causing amino acid substitutions, and the third was a single-base deletion causing a frameshift. All three mutations caused alterations in the putative DNA-binding region of the SRY protein. Genomic DNA was obtained from the fathers of two of the three mutant patients: one mutation was demonstrated to be de novo, and the other was inherited. The presence of SRY mutations in three of five patients suggests that the frequency of SRY mutations in XY females is higher than current estimates.


A new source of polymorphic DNA markers for sperm typing: analysis of microsatellite repeats in single cells. We show that dinucleotide and tetranucleotide repeat polymorphisms can be analyzed in single cells without using radioactivity or denaturing gels. This provides a rich new source of DNA polymorphisms for genetic mapping by sperm typing. The recombination fraction between two CA repeat polymorphisms was determined after whole genome amplification of single sperm, followed by typing of two different aliquots, one aliquot for each polymorphic locus. Single-cell analysis of microsatellites may also be valuable both for preimplantation genetic disease diagnosis based on single-blastomere or polar-body analysis and for the typing of forensic or ancient DNA samples containing very small amounts of nucleic acid.


Independence of VNTR alleles defined as floating bins. Data bases of VNTR fragments determined for Caucasians and blacks by Cellmark Diagnostics and Lifecodes Corporation are analyzed for independence of variants within and between loci. Floating bins are constructed around specific fragment lengths and are used to define discrete genotypes. Simple chi 2 test statistics for independence of bins within and between loci are described and applied to large sets of randomly generated four-locus profiles. The proportions of significant test statistics were about as expected under the hypotheses of independence, suggesting the absence of both Hardy-Weinberg and linkage disequilibrium. In any particular forensic application, however, these tests need to be performed on the fragments in question.


Linkage and mutational analysis of familial Alzheimer disease kindreds for the APP gene region. A large number of familial Alzheimer disease (FAD) kindreds were examined to determine whether mutations in the amyloid precursor protein (APP) gene could be responsible for the disease. Previous studies have identified three mutations at APP codon 717 which are pathogenic for Alzheimer disease (AD). Samples from affected subjects were examined for mutations in exons 16 and 17 of the APP gene. A combination of direct sequencing and single-strand conformational polymorphism analysis was used. Sporadic AD and normal controls were also examined by the same methods. Five sequence variants were identified. One variant at APP codon 693 resulted in a Glu-->Gly change. This is the same codon as the hereditary cerebral hemorrhage with amyloidosis-Dutch type Glu-->Gln mutation. Another single-base change at APP codon 708 did not alter the amino acid encoded at this site. Two point mutations and a 6-bp deletion were identified in the intronic sequences surrounding exon 17. None of the variants could be unambiguously determined to be responsible for FAD. The larger families were also analyzed by testing for linkage of FAD to a highly polymorphic short tandem repeat marker (D21S210) that is tightly linked to APP. Highly negative LOD scores were obtained for the family groups tested, and linkage was formally excluded beyond theta = .10 for the Volga German kindreds, theta = .20 for early-onset non-Volga Germans, and theta = .10 for late-onset families. LOD scores for linkage of FAD to markers centromeric to APP (D21S1/S11, D21S13, and D21S215) were also negative in the three family groups. These studies show that APP mutations account for AD in only a small fraction of FAD kindreds.


Organic solvent encephalopathy: an old hazard revisited. This report describes neurologic and respiratory symptoms among 26 engineers and contract laborers who used organic solvents and detergents to remove polychlorinated biphenyl contamination from a poorly ventilated factory basement. Neurologic symptoms included persistent central nervous system deficits; these developed in one worker after only 3 days. Respiratory symptoms included cough that persisted for more than 2 years. Laborers were more likely to report symptoms than were engineers. Appropriate ventilation or respirator use might have prevented the workers' morbidity. This incident serves as a reminder that organic solvent-related occupational illness continues to occur despite worker-health regulations and knowledge of preventive measures.


Further scientific issues in determining an occupational standard for cadmium. This contribution responds to the recent paper of Thun et al. (American Journal of Industrial Medicine 20:629-642, 1991) on an occupational standard for cadmium. The contribution of non-invasive in situ measurements of cadmium in liver and in kidney to the study of cadmium industrial toxicology is particularly reviewed. It is contended that clear scientific grounds do not exist for recommending cadmium in air occupational standard below 10 micrograms m-3, and that other arguments would need to be adduced to support a recommendation for a lower level. Last, a number of unanswered questions are identified and the need for further work is highlighted.


Health physics: its development, successes, failures, and eccentricities. Health Physics began at the University of Chicago as a science and profession during the early World War II years. It was initiated by Drs. A.H. Compton and R.S. Stone, director and associate director, respectively, of the early Plutonium Project cryptically called the Metallurgical Laboratory. It was to be a science and a profession to protect radiation workers and members of the public from exposure to ionizing radiation. It succeeded to some extent in this objective but during the past decade in the United States, it has reverted into an organization primarily to protect the nuclear industry from liability resulting from radiation exposure.


Disease clusters in occupational medicine: a protocol for their investigation in the workplace. Disease clusters have been an important source of epidemiologic and medical information in the history of occupational medicine. Many accepted disease-exposure linkages were first observed and investigated as disease clusters in the workplace setting. Recent interest in disease cluster methodology has focused on traditional environmental settings. There has been very little work on a similar methodology for the investigation of disease clusters in the workplace, despite the many advantages of workplace cluster investigations for recognizing new etiologic associations. In this paper, a protocol is proposed and discussed which can be implemented in both acute and chronic disease cluster outbreaks in the workplace, where no obvious previously recognized cause is identified. A standardized approach to occupational disease cluster investigation will lead to increased efficiency, decreased social-political tensions, and a greater yield of scientific information.


Lung function and exposure to asbestos among vehicle mechanics. Vehicle mechanics (n = 99) exposed to asbestos (annual median value 0.08 f/ml), and local controls (n = 83) not occupationally exposed to asbestos were studied with regard to symptoms and pulmonary function. The inclusion criteria to participate in this study was an age of at least 40 years with no known exposure to lung irritating agents, and for the exposed subjects, more than 15 years occupational exposure to asbestos with at least 20 years from the first exposure. The subjects were studied during identical conditions by means of dynamic and static spirometry, single breath wash-out with nitrogen (N2) and carbon monoxide (CO). The median for cumulative exposure of asbestos during the entire work life among the studied mechanics was 2.3 f*y/ml. The mechanics had reduced transfer factor (TLCO), after adjustment for age, height, and smoking category. A significant dose-response relationship was noted between the cumulative exposure of asbestos and CV%. The findings suggest a slight influence of small airways and alveoli. The evaluation of the prognostic significance of this requires a longitudinal study.


General mortality and respiratory cancer among a cohort of male chemical workers in California. Cohort mortality and nested case-control studies were conducted involving 2,901 men employed 1 year or more between 1940 and 1986 at any of four California facilities of a major chemical company. Employees experienced fewer deaths from each of the major causes than were expected based on U.S., California, and local county mortality rates. Respiratory cancer was significantly elevated in one socioeconomic category comprised of operators (SMR = 157, 95% CI = 109-220). The 34 cases who died from respiratory cancer and 136 matched controls, all of whom were operators, were included in a nested case-control study. Departments in which subjects had worked were grouped into 13 work assignment or product categories by an industrial hygienist without knowledge of case-control status. Smoking habits and other occupational exposures were ascertained by telephone interview from subjects or surrogate-responders. As expected, current cigarette smoking was strongly related to respiratory cancer. After adjustment for smoking, cases were significantly more likely than controls to have ever worked in one of the 13 work areas (supervision, services, and business support). However, no dose-response relationship was evident with duration of employment in this work area and the departments involved were associated with plant security and not chemical production. Results were similar when a 15-year latency period was assumed. These findings suggest that the excess of respiratory cancer mortality among operators was most likely due to differences in cigarette smoking or other factors not ascertained, rather than to a specific occupational exposure.


Assessment of exposure to carbon disulfide in viscose production workers from urinary 2-thiothiazolidine-4-carboxylic acid determinations. The follow-up of environmental carbon disulfide (CS2) exposure and urinary excretion of 2-thiothiazolidine-4-carboxylic acid (TTCA) among 20 operatives over a 4-day working week in two viscose producing factories confirmed earlier observations that TTCA is a sensitive and reliable indicator of exposure to CS2. Exposure to as low as 0.5-1.0 ppm (1.6-3.2 mg/m3) of CS2 (8-hour time-weighted average [TWA]) was associated with detectable amounts of TTCA in end-of-shift urine. Moreover, the excretion of TTCA, relative to estimated CS2 uptake, appeared surprisingly constant in the studied work force. Approximately 3% (range 2-6.5%) of absorbed CS2 was detected in urine as TTCA. The proportional TTCA excretion did not show dose dependency in the estimated CS2 dose range which varied by about 20-fold. TTCA elimination exhibited both a fast (T 1/2 6 hour) and a slow (T 1/2 68 hour) phase. The slow elimination is compatible with a high lipid solubility and reversible protein binding of CS2. Consequently, urinary excretion of TTCA, relative to CS2 exposure, increased by about a third during the workweek. Urinary TTCA concentration of 4.5 mmol/mol creatinine in a postshift sample corresponded to a TWA exposure to 10 ppm CS2 towards the end of the working week.


Hormone status in occupational toluene exposure. Twenty toluene-exposed rotogravure printers, without signs of solvent-induced toxic encephalopathy, had lower median plasma levels of follicle stimulating hormone (FSH) (3.2 vs. 4.9 IU/L; p = .02) and luteinizing hormone (LH) (6.4 vs. 7.2 IU/L; p = .05) and also lower serum levels of free testosterone (7.8 vs. 86.8 pmol/L; p = .05), respectively, than 44 unexposed referents. The individual time-weighted toluene levels in air were 36 (median; range 8-111) ppm. The printers' median toluene levels in blood were 1.7 (1.0-6.6) mumol/l, and in subcutaneous adipose tissue 5.7 (2.5-21) mg/kg fat. There was a negative association between blood toluene and plasma levels of prolactin. In eight printers, the levels of FSH and LH increased during a 4 week vacation, while the levels of thyroid stimulating hormone, free triiodothyronine, and free thyroxine decreased during the same period. The results indicate a slight, reversible effect of toluene on the cortical level or on the hypothalamic-pituitary axis at exposures well below the permissible levels, possibly mediated through an effect on catecholamine neurotransmission.


Reevaluation of silicosis and lung cancer in North Carolina dusty trades workers. We previously reported on the lung cancer mortality through 1983 of 760 males who were diagnosed with silicosis during 1930-1983 by the State of North Carolina's medical examination program for dusty trades workers. The lung cancer SMR (95% confidence interval) was 2.6 (1.8-3.6) among 655 white members of this group. In this paper, we report the results of a reanalysis of mortality among a subgroup for whom chest radiographs were currently available for rereading. Technically acceptable radiographs were available for 306 white males and were independently reclassified for pneumoconiosis by 3 "B" readers using the 1980 ILO Classification. Lung cancer SMRs were 1.7 (0.8-3.1) for the entire group of 306 white males, 2.5 (1.1-4.9) for 143 subjects reclassified as simple silicosis, and 1.0 (0.1-3.5) for 96 subjects whose radiographs were reclassified as ILO category 0. There were no lung cancer deaths among 67 subjects whose radiographs were reclassified as progressive massive fibrosis. Corresponding lung cancer SMRs for subjects who had never been employed in a job with exposure to known occupational carcinogens were 1.2 (0.2-4.4) for those reclassified as category 0, and 2.4 (1.0-5.0) for those reclassified as having simple silicosis. The age-adjusted lung cancer rate ratio among subjects with simple silicosis compared to those with category 0 was 1.5 (0.4-5.8). Our findings from this reanalysis, which effectively controls for misclassification of silicosis due to errors in radiograph interpretation by North Carolina program readers, offer additional evidence consistent with the hypothesis of an association between silicosis and lung cancer in this study group.


Respiratory disorders and atopy in cotton, wool, and other textile mill workers in Denmark. A cross-sectional study of respiratory disorders and atopy in Danish textile industry workers was conducted to survey respiratory symptoms throughout the textile industry, to estimate the association of these disorders with atopy, and to study dose-response relationships within the cotton industry. Workers at cotton mills, a wool mill, and a man-made fiber (MMF) mill were examined. Four hundred nine (90%) of the 445 workers participated in this survey, i.e., 253, 62, and 94 workers at the cotton mills, the wool mill, and the MMF mill, respectively. An interview designed to assess the prevalence of common respiratory and allergic symptoms was given to all workers willing to participate, and blood samples were drawn. Lung function measurements determined a baseline FEV1, FVC and the change in FEV1 and FVC during work hours on a Monday. The working environment was examined for dust, bacteria, endotoxins, and molds, and the exposure was estimated for each participant. The mean personal samples of airborne respirable dust and respirable endotoxin were highest in the cotton industry, i.e., 0.17-0.50 mg/m3 and 9.0-126 ng/m3 respectively, whereas mold spores were found in the highest concentrations in the wool mill: 280-791 colony-forming units (cfu)/m3. Only small concentrations of microorganisms were found in the MMF mill. The mean change in FEV1% and FVC% was greatest among atopic individuals in both cotton and wool industry and other textile industries although the differences were not significant. FEV1% and FVC% in the cotton workers were significantly associated with the cumulative exposure to respirable endotoxin. Byssinosis was diagnosed only in the cotton industry. We found a dose-response relationship between endotoxin exposure and byssinosis, and a significant association between A-1-A serum concentrations less than or equal to 35 mumol/liter and byssinosis, a finding we are further evaluating in subsequent studies.


Localized pleural plaques and lung cancer. In a mass chest radiography survey conducted in 1971 for 7,986 residents of three Finnish communities, 604 subjects (7.6%) with pleural plaques but not other asbestos-related radiographic signs were identified. The same number of referents, each individually matched to each plaque carrier on sex, birth year, and community, was selected from among persons in the same source population with no pleural plaques. The two groups were followed for investigation of incidence of lung cancer during 1972-1989. Twenty-eight of those with plaques and 25 referents contracted lung cancer (crude conditional RR = 1.1; CL95 = 0.7, 1.9). The application of the proportional hazards model, with adjustment for sex, age, and residence, resulted in a hazard ratio of 1.1 (CL = 0.6, 1.8). The risk ratio estimate may be biased; hence, the result is inconclusive in regard to the predictive assessment of lung cancer risk among carriers of pleural plaques.


Asbestos fiber analysis in 27 malignant mesothelioma cases. The asbestos body counts per 5 gm wet lung tissue in 27 (23 pleural and 4 peritoneal) malignant mesothelioma cases derived from 19 autopsy and 8 surgical cases were, according to our own criteria, low level exposure in 13 cases (48.2%), moderate level exposure in 2 cases (7.4%), and high level exposure in 12 cases (44.4%). In our previous study on 235 consecutive autopsy cases, the low level exposure was considered to be environmental, the moderate level was secondary or blue collar, and the high level was occupational. In the present study, about half of the cases examined (44.4%, high level exposure) are closely related to some occupational asbestos exposure and the other half (48.2%) to environmental exposure. The type and size of asbestos fibers from the 12 cases of high level exposure were analyzed and the characteristics were compared with those of cases of low level exposure without lung cancer or mesothelioma. Most fibers analyzed (98%) were longer than 5 microns and thicker than 0.10 micron by our counting rules. In the control group, predominant fibers were tremolite or actinolite. In all the 11 pleural mesothelioma cases, the content of amosite fibers was significantly higher than in the controls. In one case of peritoneal mesothelioma, incipient asbestosis was found and the predominant fibers were crocidolite. It is suggested that the presence of amosite and crocidolite is linked to mesothelioma. The mean lengths of amosite and crocidolite, as detected by our resolution capabilities, were 36.0 and 20.9 microns, and the mean diameters were 0.51 and 0.27 micron, respectively. Both amosite and crocidolite fibers had high aspect ratios (94.2 and 115.4).


A retrospective mortality study within operating segments of a petroleum company. This retrospective mortality study was conducted among 34,597 oil industry workers in diverse operating segments. Employees were traced through Statistics Canada, and overall mortality (SMR = 0.85) was lower than general population rates and similar to other petrochemical cohorts. The most notable finding was a significant excess of malignant melanoma [observed deaths (N) = 16, SMR = 1.87, 95% CI = 1.07, 3.04], which concentrated among upstream workers (N = 6, SMR = 6.00, 95% CI = 2.19, 13.06), and was directly related to employment duration and latency. Specific substances or hydrocarbon (HC) streams could not be implicated, although possible explanations include dermal HC exposure, ultraviolet light exposure, or a synergistic effect between these two factors. Marketing/transportation workers showed a non-significant excess of multiple myeloma (SMR = 1.81), which was also related to employment duration, latency, and commencement of employment before 1950. Lymphatic cancer, skin cancer, and kidney cancer mortality was not elevated in refinery workers, a finding at odds with some previous refinery worker studies. Although the malignant melanoma and possibly the multiple myeloma mortality patterns are consistent with an occupational link, further studies are needed to investigate the relationship of these diseases with particular exposures.


An automated method for the determination of acetyl and pseudo cholinesterase in hemolyzed whole blood. The aim of the present study was to develop a method which allows determination of pseudo (PsChE) and acetyl cholinesterase (AChE) activities in single hemolyzed blood samples of workers exposed to cholinesterase-inhibiting compounds, avoiding the time-consuming and laborious separation of plasma and erythrocytes. Two methods based on Ellman's colorimetric determination of cholinesterase activity were compared, and three different substrates were tested. The best results were obtained with the substrates butyrylthiocholine and acetyl(beta-methyl)thiocholine, both showing a substrate specificity of more than 97% with respect to PsChE and AChE, respectively. The method showed sensitivity to detect low levels of inhibition of AChE and PsChE in blood. The between-day precision was less than 4% for both cholinesterase activities. It was demonstrated with this method that hemolyzed blood can be stored at -20 degrees C at least 18 months without loss of cholinesterase activity. The method has been used for 18 months in a monitoring program for laboratory employees working with various cholinesterase-inhibiting compounds. The average co-efficients of intraindividual variation amounted to 6.8% (range 2.2-9.6%; 90 percentile, 8%) and 6.6% (range 2.9-9.9%; 90 percentile, 7.9%) for PsChE and AChE, respectively. In a group of non-exposed workers the average intraindividual variations were 4.0% (range 1.5-7.7%; 90 percentile, 7.6%) and 3.6% (range 0.6-6.6%; 90 percentile, 5.3%), respectively. Using the value of 4.0%, it appears possible to detect an individual decrease in cholinesterase activity of more than 8% below a baseline based on three determinations. The method can thus be used to detect relatively low levels of cholinesterase inhibition.


Biological monitoring of three 60Co radiation incident victims. Radiation-induced structural chromosomal aberrations were the only adverse effects found in three workers overexposed to 60Co gamma-radiation. Chromosomal analyses were performed on the 5th and 75th days after exposure. Hematologic follow-up was carried out on the 5th, 12th, 16th, and 75th days after exposure. Hematologic findings did not differ over time in any of the three exposed workers. In two workers, we found dicentric chromosomes, which are conventional indicators for exposure to ionizing radiation.


Medical management of three workers following a radiation exposure incident. The medical management of three individuals involved in an exposure incident to whole-body radiation at a nuclear generating plant of a Canadian electrical utility is described. The exposure incident resulted in the two highest whole-body radiation doses ever received in a single event by workers in a Canadian nuclear power plant. The individual whole-body doses (127.4 mSv, 92.0 mSv, 22.4 mSv) were below the threshold for acute radiation sickness but the exposures still presented medical management problems related to assessment and counseling. Serial blood counting and lymphocyte cytogenetic analysis to corroborate the physical dosimetry were performed. All three employees experienced somatic symptoms due to stress and one employee developed post-traumatic stress disorder. This incident indicates that there is a need in such radiation exposure accidents for early and continued counseling of exposed employees to minimize the risk of development of stress-related symptoms.


Cancer risk in patients with cold thyroid nodules: relevance of iodine intake, sex, age, and multinodularity. We evaluated the frequency of thyroid cancer in patients with cold thyroid nodules in relation to iodine intake, sex, age, and multinodularity in a consecutive series of patients with nodular thyroid diseases. In the period from 1980 to 1990, 5,637 patients were studied: 4,176 patients were from an iodine-sufficient area (ISA) and 1,461 from an adjacent iodine-deficient area (IDA). Surgery was performed in 792 patients on the basis of a suspicious or malignant finding at fine-needle aspiration biopsy. The overall thyroid cancer frequency was 4.6% (259 patients had cancer). Iodine intake affected the cancer rate in patients with cold nodules. The frequency of cancer in patients with cold thyroid nodules was 5.3% in the ISA and 2.7% in the IDA. This difference, however, was significant only in females. Sex had a major influence on the malignant rate of cold nodules; although female patients were more frequently observed (n = 5,028) than male patients (n = 609), the frequency of cancer was significantly lower in female patients with cold nodules (4.2%) than in males (8.2%). Age was an important factor in both sexes. The proportion of nodules that were malignant was smallest in patients of the 4th decade and was greatest in patients younger than 30 years or older than 60 years. Multivariate analysis showed that sex and age interact in determining the cancer risk in patients with thyroid nodules. Finally, the frequency of thyroid cancer in patients with a solitary nodule was not different from the frequency in patients with multiple nodules. Our study indicates that thyroid cancer risk in a patient with a nodular goiter varies markedly according to iodine intake, sex, and age but not in relation to multinodularity, as assessed by clinical examination. The knowledge of these epidemiologic aspects of thyroid cancer may increase the accuracy of the preoperative selection of patients with cold nodules of the thyroid.


Human immunodeficiency virus infection in intravenous drug users: a model for primary care. Intravenous drug users (IVDUs) often encounter barriers to primary care. To improve access, we developed a primary care clinic--Central Medical Unit (CMU)--for substance abusers in drug treatment. We report outcomes for services offered to IVDUs with human immunodeficiency virus (HIV) infection. During 1990, 24% (120 of 509) of IVDUs eligible for CMU were HIV positive. Diagnostic therapeutic and preventive goals for IVDUs with HIV infection were evaluated for acceptance and compliance by chart review for these 120 patients. On admission, 65% (78 of 120) of patients reported having no source of primary care, 64% (77 of 120) were male, and 77% (92 of 120) were in methadone maintenance. All were screened for tuberculosis, syphilis, and hepatitis; 94% (15 of 16) of eligible patients accepted tuberculosis prophylaxis and 83% (5 of 6) accepted syphilis treatment, but only 36% (5 of 14) accepted hepatitis B vaccine. Of those who accepted therapy, 87% (13 of 15) were compliant with tuberculosis prophylaxis, and 100% (5 of 5) were compliant with syphilis treatment. Influenza vaccine was accepted by 49% (59 of 120) and pneumococcal vaccine by 81% (97 of 120). Ninety-eight percent (118 of 120) accepted T-cell testing: 61% had T-helper counts less than 500/mm3 and 25% were less than 200/mm3. Of those eligible, 89% (70 of 79) accepted antiretroviral therapy, and 100% (35 of 35) accepted Pneumocystis carinii pneumonia prophylaxis. Six-month compliance rates for these therapies were 84% (59 of 70) and 77% (27 of 35), respectively. By offering primary care services with drug treatment, the CMU model may be an effective way of providing access to primary care for HIV-infected IVDUs and for facilitating compliance.


Causes of death in persons with human immunodeficiency virus infection. Pneumocystis carinii pneumonia (PCP) was reported to be the predominant cause of human immunodeficiency virus (HIV)-related deaths prior to 1988, the year that effective prophylaxis against PCP entered routine use. Our study was performed to study the causes of HIV-related death since January 1988 in a region where patient tracking is virtually complete. We surveyed physicians associated with the Brown University Acquired Immunodeficiency Syndrome (AIDS) Program who cared for greater than 95% of known HIV-positive patients in Rhode Island. These physicians identified all those HIV-infected persons who had died under their care between January 1988 and July 1990, and determined these patients' causes of death by chart review. For comparison, death certificates of identified persons were also reviewed at the Rhode Island Department of Vital Statistics. Among 126 deaths since January 1988, bacterial infections were the most common cause of death (30%), whereas PCP was responsible for only 16% of deaths. Persons not receiving any form of PCP prophylaxis were more likely to die from PCP than were those who received prophylaxis (26% versus 11% [p = 0.04]). Cause of death as recorded on actual death certificates was imprecise, although bacterial infections were again the most common cause indicated. Only one death occurred in a patient with a CD4 count greater than 200/mL, and this was not HIV-related. PCP has not been the leading cause of death in our region since January 1988. Bacterial infections contribute substantially to mortality, and this may influence future prophylactic regimens. HIV-related deaths in patients with CD4 counts greater than 200/mL are unusual.


Idiopathic intracranial hypertension: report of seven cases. We describe seven patients with idiopathic intracranial hypertension (IIH), a disorder, mostly in young women, characterized by papilledema, elevated cerebrospinal fluid (CSF) pressure, normal CSF composition, and normal neuroradiologic studies. Obesity, the most consistent etiologic association, was present in two of our patients. Hypothalamic compression in IIH may induce increased appetite and result in weight gain. Use of trimethoprim/sulfamethoxazole has been reported to be associated with IIH and was seen in one of our patients. IIH is an important diagnostic consideration in the differential diagnosis for a patient with headache, visual disturbances, and papilledema.


Interaction of cyclosporine A and nonsteroidal anti-inflammatory drugs on renal function in patients with rheumatoid arthritis. To determine the additive renal effects of nonsteroidal anti-inflammatory drugs (NSAIDs) and cyclosporine A (CYA) in patients with rheumatoid arthritis (RA) and to determine the effects of CYA on active RA. Eleven patients with RA refractory to other agents were treated separately for 2-week periods with an NSAID (sulindac or naproxen), CYA (5 mg/kg/d), and NSAID plus CYA in combination (NSAID/CYA). The NSAID/CYA combination was continued for an additional 20 weeks. Clinical parameters of RA, electrolytes, renal function, and the renin-aldosterone system were evaluated at each interval to determine the potential interaction of these two agents. Combined therapy was effective in suppressing many measures of active RA in 9 of the 11 patients. Adverse drug reactions were common, but withdrawals were limited to hirsutism (one) and peripheral neuropathy (one). In about half of the patients, CYA or NSAID resulted in a decrease in the glomerular filtration rate (GFR) and effective renal plasma flow (ERPF), with a mild reduction in the filtration fraction. With NSAID or CYA, early morning renin-aldosterone system values were mildly suppressed, and their response to ambulation/intravenous (IV) furosemide was not blunted. When combined, NSAID/CYA caused more marked reductions of GFR and ERPF at 2 weeks, and this persisted at 20 weeks. The morning renin-aldosterone system values during administration of NSAID/CYA were suppressed, with an added blunted response to ambulation/IV furosemide. As previously suspected, the impairment of renal function when CYA and NSAID are combined is greater than that obtained with either agent alone. This hemodynamic effect was reversible and appeared to be, at least in part, due to renal vasoconstriction.


Prevention of anticardiolipin antibody-related pregnancy losses with prednisone and aspirin. Prevention and treatment of pregnancy loss associated with the antiphospholipid syndrome (APS) are controversial. Successful pregnancies have been reported with prednisone and low-dose aspirin in patients with lupus anticoagulant and anticardiolipin antibodies (aCL), but failure has also been reported. The purpose of this prospective study was to define the efficacy of such combination therapy in the prevention of pregnancy loss related to aCL. Consecutive pregnant patients with a minimum of one pregnancy loss and at least two positive aCL determinations more than 3 months apart, and in whom other causes of pregnancy loss were ruled out, were included in the study. aCL concentrations were determined by enzyme-linked immunosorbent assay before and during therapy. Patients received prednisone, at a dosage of 40 mg/d, for 4 weeks. The dose was then tapered down 10 mg every 4 weeks, and then to a maintenance dose of 5 mg/d. They also received aspirin, 81 mg/d, throughout the pregnancy. Babies were evaluated during the pregnancy by measurement of fetal heart rate and ultrasonography, and after the delivery by measurement of weight and Apgar scores, and, in some cases, by arterial gasometry. Eleven patients with a mean (+/- SD) age of 33.2 +/- 5.01 years were included. Prior to therapy, the rate of live-born babies was 15.6% (32 previous fetal losses and 5 live-born babies), and, after therapy, it was 100% (12 pregnancies and 12 live-born babies). There were no significant adverse effects to either mothers or babies. All the patients had positive aCL determinations. Nine patients had positive IgG aCL. The levels of the antibodies decreased during treatment in these nine patients. IgM aCL determinations were positive in nine patients. The levels of this isotype decreased in eight patients (90%) during treatment. Treatment with prednisone and aspirin appears to be efficacious, safe, and economic in the prevention of pregnancy loss and fetal growth retardation in patients with aCL.


Implementation of capillary blood glucose monitoring in a teaching hospital and determination of program requirements to maintain quality testing. To study the implementation of bedside capillary glucose monitoring using a hospital-wide quality control (QC) program. A prospective study of QC performance in 7 outpatient and 39 inpatient treatment units was performed in a large teaching hospital over a 2-year period. Approximately 800 nurses were trained to perform bedside capillary glucose monitoring (Accu-Chek II, Boehringer-Mannheim, Indianapolis, IN). An eight-point QC program was instituted including proficiency testing, instrument maintenance, performance of daily controls, storage of reagent strips and supplies, instrument calibration, and documentation procedures. Comparison of laboratory and bedside test results (split-sample proficiency testing) revealed Y = 1.004X + 7.26, r = 0.95, with a mean percent difference of -4.2% (p < 0.001). Less than 7% of results fell outside +/- 20% of the laboratory results. QC scores (0 = worst to 4 = best), based on adherence to the QC program, improved from 0 on the first inspection to 3.7 +/- 0.17 by the 11th inspection. The most common QC deficiencies were failure to perform split-sample testing (41.4%) and failure to perform instrument maintenance (30.2%). Significant differences were noted in the QC performance of different types of medical services. During the 2-year study period, the total number of glucose assays performed in the clinical laboratories decreased by 22.2% concurrent with initiation of bedside testing. The number of instruments in the hospital increased from 10 to 46. Bedside capillary glucose assays can be widely implemented in large hospitals with an acceptable degree of accuracy. QC programs with frequent inspections are necessary to identify units that function inadequately, and a formal disciplinary policy is required to ensure compliance with the program.


Epidemiologic features and clinical presentation of acute Q fever in hospitalized patients: 323 French cases. To contribute to the knowledge of epidemiologic and clinical features of patients hospitalized with Q fever in France. We conducted a retrospective analysis of 22,496 sera submitted between 1982 and 1990 to the French National Reference Center for Rickettsial Diseases (NRC). The diagnosis of acute Q fever was based on an IgG titer greater than or equal to 1:200 and an IgM titer greater than or equal to 1:25 against phase II Coxiella burnetii antigen on an indirect immunofluorescence test (IFA). Fifteen cases prior to 1985 were diagnosed on the basis of a complement fixation titer greater than or equal to 1:8. A serosurvey of blood donors from Marseille was also conducted in 1988 on 924 sera, using IFA with a cutoff titer of 1:25. The serosurvey conducted in 1988 showed a seroprevalence of 4.03%, without age or sex prediction. The incidence rate of acute Q fever detection at the NRC was 0.58 per 100,000 inhabitants over the 9-year period. Three hundred twenty-three clinical cases were diagnosed, rising from 1 in 1982 to 107 in 1990. In patients hospitalized for acute Q fever, there was a significantly higher sex ratio of males to females (2.3), which, coupled with the age distribution, indicated that elder males, who are overrepresented due to our recruitment bias, are more susceptible to C. burnetii infections. The mean age of the patients was 45.5 years, while the risk was increased in the 30 to 39 age group as well as in the 60 to 69 age group. Usual epidemiologic risk factors were found in 20.1% of the cases. Hepatitis (61.9%) was a more common clinical presentation in our patients with Q fever than pneumonia (45.8%). This might reflect differences in strains of C. burnetii or the biology of the host. However, French farmers and stock breeders commonly drink unpasteurized raw milk from their cattle, which might indicate a relationship between hepatitis and infection via the digestive tract. Our results indicate that many cases of acute Q fever are undiagnosed. A greater awareness of the disease and more extensive serologic testing of patients with symptoms compatible with Q fever may improve the situation.


Splenectomy in advanced chronic lymphocytic leukemia: a single institution experience with 50 patients. To assess the efficacy of splenectomy in the treatment of refractory cytopenias associated with advanced chronic lymphocytic leukemia (CLL). The histories of 57 patients with CLL who underwent splenectomy at the Mayo Clinic between 1975 and 1991 were retrospectively reviewed. Of the 57 patients, 50 underwent splenectomy for reasons directly related to their disease process such as cytopenias or symptomatic splenomegaly. The histories from these 50 patients were studied to assess the response to splenectomy and the operative morbidity and mortality. Ninety-four percent of patients were in Rai stage III or IV with extensive marrow infiltration, massive splenomegaly, and cytopenias refractory to chemotherapy. A positive response to splenectomy was defined at 3 months of follow-up as: (1) a hemoglobin level of 11 g/dL or greater in a patient with a preoperative value less than 11 g/dL; or (2) a platelet count of 100 x 10(3)/mm3 or greater in a patient with a preoperative value less than 100 x 10(3)/mm3. A positive response was achieved in 77% of patients with anemia, 70% of patients with thrombocytopenia, and 64% of patients with both anemia and thrombocytopenia. The response was sustained at 1 year of follow-up in 86%, 84%, and 85% of the patients, respectively. Postoperative transfusion requirements decreased correspondingly. The operative morbidity was 26%, and the operative mortality was 4%. The mean duration of hospitalization was 9.8 days (median: 9 days; range: 5 to 24 days). The actuarial median survival after splenectomy was 41 months in responders and 14 months in nonresponders. We found no preoperative parameters that were clearly predictive of a poor hematologic response. In particular, outcome was not affected by preoperative spleen size or the degree of marrow infiltration by CLL. All patients with symptomatic splenomegaly had an improved sense of well-being. In this, the largest single institution study to date, we found splenectomy to be efficacious in providing durable remissions of refractory cytopenias and in relieving symptomatic splenomegaly in the majority of patients with CLL. The procedure is associated with a low perioperative mortality. Although the impact on survival is uncertain, the improved peripheral blood counts may allow the administration of adequate doses of myelosuppressive chemotherapy.


Multiple myeloma and chronic lymphocytic leukemia: parallels and contrasts. Multiple myeloma (MM) and chronic lymphocytic leukemia (CLL) are closely related B-cell cancers. Parallel and divergent features of these diseases are reviewed. In MM, expression of multiple hemopoietic lineage-associated antigens on the malignant cells and the substantial likelihood of progression to acute myelogenous leukemia suggest transformation of a pluripotent stem cell. In CLL, transformation more likely involves a committed B-cell progenitor. Another difference is that clonal evolution with associated cytogenetic progression is common in MM but not CLL. Other data, including studies of proto-oncogenes and tumor suppressor genes, suggest that MM results both from increased proliferation and accumulation of tumor cells, whereas tumor cell accumulation is the predominant feature of CLL. These differences may be reflected in the seemingly greater role of cytokine abnormalities in MM progression. For example, osteoclast-activating properties of some cytokines account for bone involvement in MM but not in CLL. MM and CLL share common features such as stage-dependent anemia and immune deficiency. Both diseases respond to alkylating agents but vary markedly in their sensitivity to fludarabine (CLL greater than MM) and glucocorticoids (MM greater than CLL). Differences between these diseases in progression-free interval and survival may reflect different definitions of premalignant and malignant phases rather than biologic differences. Detailed comparisons between MM and CLL may provide additional insights into these and related B-cell cancers.


T-cell receptor alpha/beta chain-CD3 protein complex defect in systemic lupus erythematosus: T-cell function. We describe the first case of systemic lupus erythematosus (SLE) in which peripheral blood T cells were deficient in cell surface expression of T-cell receptor alpha/beta chain (TcR alpha beta) and the CD3 protein. Because of the uncommon phenotype and because of the notion that coexpression of TcR alpha beta and CD3 is essential for antigen-specific T-cell function, in vitro functional assays were performed, showing a highly decreased proliferative response to anti-CD3 antibody and other T-cell mitogens, deficient interleukin-2 (IL-2) secretion, and impaired function to respond in autologous and allogeneic mixed lymphocyte reactions. However, the helper-inducer function of T cells was unaffected by deficient expression of the TcR alpha beta/CD3 protein complex. The relative increase of CD4+ CDw29+ helper-inducer subsets in T cells accounted for elevated secretion of two terminal B-cell stimulating factors, B-cell growth factor (BCGF) and B-cell differentiation factor (BCDF). Hence, our results suggest that the regulation of secretion of lymphokines, IL-2, and BCGF and BCDF is independently controlled in T cells, and this case illustrates the pathologic sequelae of a unique defect in T cells characteristic of SLE.


Skin necrosis and protein C deficiency associated with vitamin K depletion in a patient with renal failure. Skin necrosis similar to that induced by warfarin was seen in a patient who had never received the drug but who was vitamin K-deficient due to malnutrition and prolonged treatment with broad-spectrum antibiotics. He also had end-stage renal failure and was receiving prophylactic subcutaneous heparin therapy because of immobilization. His plasma protein C antigen level and, disproportionately, his plasma protein C functional activity were decreased. Both protein C values improved after vitamin K therapy, discontinuation of heparin, and initiation of hemodialysis. We surmise that skin necrosis occurred as a result of protein C deficiency caused by vitamin K depletion. Production of abnormal (descarboxy) protein C/protein S due to vitamin K deficiency and increased protein C inhibitory activity associated with renal failure and/or heparin administration may have contributed to the clinical picture. This rare but serious complication of a relatively common disorder, viz., vitamin K deficiency, reinforces the importance of vitamin K supplementation in malnourished patients who receive long-term antibiotic maintenance therapy.


Relationship between insulin sensitivity and degree of obesity in mild hypertension. Eighteen patients with mild hypertension (diastolic blood pressure > or = 90 and < 104 mm Hg) and 15 normotensive control subjects were studied. Insulin tolerance tests (ITT) and fasting plasma insulin (FPI) level measurements were performed to evaluate insulin sensitivity. Insulin sensitivity, as measured with the ITT, showed a strong correlation with body mass index (BMI) in the hypertensive and control groups (r = -0.68, p < 0.01 and r = -0.61, p < 0.01, respectively). The fasting insulin levels also correlated significantly with BMI in both groups (r = 0.55, p < 0.05 in the hypertensive and r = 0.76, p < 0.01 in the control group). Insulin sensitivity in the hypertensive subjects whose BMI was < or = 27.0 kg/m2 (nonobese), as measured with the ITT and FPI, was not different from the nonobese normal controls (K(itt), 5.36 +/- 1.74% min-1 versus 5.61 +/- 1.66% min-1, respectively, p > 0.2; FPI, 5.8 +/- 3.4 microU/ml versus 7.1 +/- 2.5 microU/ml, respectively, p > 0.2). Also, insulin sensitivity, as measured with the ITT, was not statistically significantly different between hypertensive and normotensive obese subjects (K(itt), 2.82 +/- 1.55% versus 3.90 +/- 0.67% min-1, respectively, p > 0.1). When fasting plasma insulin levels were compared, a higher level was observed in the obese normotensive subjects than in the obese hypertensive group (FPI, 19.8 +/- 10.0 microU/ml and 11.5 +/- 4.9 microU/ml, p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)


Cloning and expression of a human endothelin receptor: subtype A. The polymerase chain reaction, employing degenerate primers specific for the intramembrane domains III and VI of G-coupled receptors, was used to generate partial clones encoding those receptors carried by cultured rat aorta smooth muscle cells. One clone, spanning the intramembrane domains IV-VI of a receptor specific for endothelin-1 (ET-R[A]), was used as a probe to screen a human placental cDNA library. The clone pL4-3, encoding a selective type of human endothelin receptor (ET-R[A]), has an open reading frame encoding a protein 427 amino acids in length, with a relative molecular weight of 48,625 daltons. The sequence analysis suggests the presence of a signal peptide, two potential sites for glycosylation in the N terminal extracellular domain, the seven transmembrane domains typical of G-protein receptors, and several potential sites for phosphorylation in the C terminal cytoplasmic domain. At the amino acid level, the human ET-R(A) shows 91% and 94% identity with the rat and bovine ET-R(A)s, respectively, and 59% similarity with the human ET-R(B). Xenopus laevis oocytes injected with the cloned cDNA express binding sites specific for endothelin-1. Expression of the message in COS 7 cells gave a membrane-bound product to which binding of the [125I]-ET-1 was inhibited by peptide analogues specific for ET-R(A).


Comparison of four methods for assessing airway bacteriology in intubated, mechanically ventilated patients. A prospective evaluation of lower airway bacteriology from intubated, mechanically ventilated patients was performed by comparing the qualitative and quantitative recovery of bacteria using four different techniques. Twelve intubated, mechanically ventilated patients who satisfied accepted clinical criteria for the suspicion of ventilator-associated pneumonia were studied. Airway secretions were obtained from each patient by: (1) blind endotracheal aspiration (ET); (2) Accu-cath pulmonary culture catheter (Accu); (3) bronchoscopic protected specimen brush (BPSB); and (4) bronchoalveolar lavage (BAL). ET specimens were cultured semi-quantitatively (1+ to 4+) aerobically, and all other specimens were cultured quantitatively both aerobically and anaerobically. The BPSB recovered 9 organisms in > or = 10(3) colony forming units/ml, a standard number often used to indicate significant growth. Of these 9 organisms, 7 were recovered at > or = 10(3) cfu/ml by Accu, and 6 were recovered at > or = 10(4) cfu/ml by BAL. All 8 aerobic isolates recovered in > or = 10(3) cfu/ml by BPSB also were recovered by ET aspirate. Five of these were recovered in > or = 3+ semi-quantitative growth by ET aspirate. Of 30 organisms recovered in < 3+ semi-quantitative growth by ET aspirate, 28 were recovered in < 10(3) cfu/ml by BPSB, indicating a negative predictive value of 93%. Thus, it appears that these four methods provide reasonably similar qualitative and quantitative recovery of bacteria from the lower airways of intubated, mechanically ventilated patients. In addition, routine Gram's stain and semi-quantitative aerobic culture of endotracheal aspirate may provide useful information in patients with suspected ventilator-associated pneumonia.


Surfactant protein-A inhibits lavage-induced surfactant secretion in newborn rabbits. In vitro experiments with granular pneumocytes suggest that surfactant protein-A (SP-A) inhibits secretion of pulmonary surfactant. We examined whether SP-A inhibits surfactant secretion induced by lung distention during lung lavage. Human SP-A was obtained by lung lavage in a patient with pulmonary alveolar proteinosis. After centrifugation of the lavagate, the pellet was repeatedly washed with saline and then extracted with chloroform:methanol. The methanol:saline phase was separated and lyophilized to yield the SP-A product. SDS-PAGE and immunoblot analysis indicated that our preparation of SP-A had only minor contamination with human plasma proteins. To examine secretion, we used freshly killed newborn rabbit pups of 29.5 days gestation and lavaged the lungs by 10 sequential, fresh saline washes. Littermate neighbor pairs were lavaged with SP-A or human plasma protein at concentrations of 1, 6, 10, and 50 micrograms/ml, and disaturated phosphatidylcholine (DSPC) was analyzed as a marker for surfactant. The inhibition of surfactant secretion was maximal at a concentration of 10 micrograms/ml; the average yield by the last two pairs of washes, an index of surfactant secretion, was 286 +/- 41 micrograms/g dry lung weight for SP-A, compared to 405 +/- 37 micrograms/g dry lung weight for controls, an inhibition of 30% (p < 0.005). There were no changes in the volumes of returned lavage or in the concentrations of lactate dehydrogenase or DNA. To test whether SP-A increased cellular uptake of DSPC in the lungs, we prepared radioactive exogenous surfactant, lavaged it into the lungs, and monitored recovery of radioactivity by continued lavage. Recovery was the same in treated and control lungs.(ABSTRACT TRUNCATED AT 250 WORDS)


Case report: lymphadenopathy, perinodal granulomatosis, and immunologic aberrations. The authors report on a patient with an undescribed constellation of lymph nodal plasmacytosis, perinodal epithelioid cell granulomas and fibrosis as well as anti-Sm and anti-phospholipid antibodies. The illness does not meet the criteria of well-known nosologic entities, but it is thought to represent an unrecognized nosological entity within the group of undifferentiated immune disorders.


Case report: stimulation of severe hypertension as a means of malingering. Severe hypertension frequently requires hospitalization. Although hospital admission is undesirable for most patients, others are motivated to achieve hospitalization status for secondary gain. The authors present a case of a prison inmate who simulated severe hypertension with a combination of Valsalva's maneuver and arm flexion, on the background of preexisting essential hypertension and mitral valve prolapse. His secondary intent--to avoid his prison duties--classifies him as a malingerer. The differences between this malingering and the psychiatric diagnosis of Munchausen syndrome are discussed. The contributions of essential hypertension and mitral valve prolapse to the self-induced blood pressure elevations also are considered.


Loxoscelism.

Loxoscelism. Loxoscelism, or envenomation by the brown recluse spider, may result in necrotic lesions and systemic reactions, including hemolytic anemia. Histologically, it resembles a cutaneous Arthus reaction. The reaction mechanism involves interactions between complement, neutrophils, and the clotting system. It is best treated with analgesics, avoidance of early surgical debridement, and oral dapsone.


Five years experience of predictive testing for myotonic dystrophy using linked DNA markers. We report on a 5 year experience in providing presymptomatic and prenatal molecular diagnostic services for myotonic dystrophy, using closely linked markers, representing 235 completed results in 161 families. Only 10 analyses (4.3%) proved uninformative, but a further 5 requests (1.9%) could not be reported because of uncertainty in clinical status. Seven of 81 (8.6%) patients considered to be at low risk on clinical grounds were found to be at high risk of carrying the gene. The importance of interpreting molecular results in conjunction with clinical findings is emphasised by the illustrative examples provided. Careful clinical examination and appropriate investigation remain a cornerstone of diagnosis in myotonic dystrophy and are crucial if errors in assigning genotype status by molecular means are to be minimised.


X inactivation and dystrophin studies in a t(X;12) female: evidence for biochemical normalization in Duchenne muscular dystrophy carriers. A 4-year-old girl was identified with high creatine kinase (CK) values, and mild muscle weakness in a limb-girdle distribution. Results of dystrophin analysis of the muscle biopsy were consistent with a manifesting heterozygote for Duchenne muscular dystrophy. In peripheral lymphocytes she had a t(X;12) (p21.2;q24.33). Late DNA replication studies demonstrated inactivation of the normal X chromosome in 99.4% of cells. Dystrophin immunofluorescence showed 64% dystrophin-negative muscle fibers. Dystrophin content of muscle by immunoblot was approximately 5% of normal. The discordance between the percent of normal X inactivation and percent of dystrophin-negative cells may be explained by compensatory protection of dystrophin by rare nuclei with the normal X active in multi-nucleated muscle fibers with shared cytoplasm.


Can maternal risk factors influence the presence of major birth defects in infants with Down syndrome? Although the manifestations of Down syndrome (DS) are well known, certain major birth defects such as duodenal atresia and endocardial cushion defects are present in some infants but not others, suggesting the possible role of other genetic or environmental factors interacting with the trisomy genotype. To explore the possible role of maternal factors in the presence of major defects among DS infants, we examined data from an epidemiologic study of DS conducted in metropolitan Atlanta. Of 219 DS infants born between 1968 and 1980, 50 had recorded cardiac defects, 9 had selected gastrointestinal atresias and 4 had oral clefts. We evaluated the association of these defects with several maternal factors including age, race, first trimester cigarette smoking, alcohol use, and fever. We found that different maternal factors were associated with several defects: (1) mother's race with cardiac defects (40% in blacks vs. 17% in whites, P less than 0.01), (2) mother's age with oral clefts (6% for less than 25 years, 1% for 25-34, and 0% for greater than 34, P less than 0.05), and (3) maternal first trimester fever with gastrointestinal defects (15% in infants with history of fever and 3% in infants without a history of fever, P less than 0.01). We also observed an inverse relationship between maternal alcohol use and the presence of ventricular septal defect. These findings suggest that maternal risk factors may influence the clinical manifestations of DS. In addition to searching for a genetic basis for the DS phenotype, we suggest that the role of environmental factors and maternal exposures be specifically explored in clarifying the genesis of various birth defects in Down syndrome.


Detection of the heteromorphic spectrum of heterochromatin in the human genome by in situ digestion using restriction endonuclease AluI. A battery of selective banding techniques has been utilized to identify the heteromorphic markers in the human genome. The recent addition of the AluI/Giemsa (G)-technique has helped not only in identifying the variable sites, but in characterizing their heteromorphic spectra. In the present investigation, we classified the pericentromeric heterochromatin by the AluI/G-technique by its size and position using 50 normal individuals and suggested the potential uses of this banding technique over earlier methods.


Microcephaly, lymphedema, and chorioretinal dysplasia: a distinct syndrome? We report on 2 unrelated patients with microcephaly, lymphedema, and chorioretinal changes. They are compared with previously reported patients with microcephaly and lymphedema and microcephaly with chorioretinal changes. The question is raised whether all of these patients represent one entity or are separate syndromes. Until more data are available we propose that our patients represent a single entity.


VACTERL with hydrocephalus: one end of the Fanconi anemia spectrum of anomalies? Two cases of Fanconi anemia presenting as hydrocephalus are discussed. Both infants had initially been considered to have features of VACTERL. Chromosomal breakage studies should be performed in all cases of VACTERL with hydrocephalus so that Fanconi anemia may be excluded.


VACTERL or MURCS association in a girl with neurenteric cyst and identical thoracic malformations in the father: a case of gonosomal mosaicism? We report on a female infant with lethal congenital malformations including extreme hydrocephalus due to aqueductal stenosis, vertebral segmentation anomalies, fused costae, anal atresia, renal dysplasia, and bicornuate uterus with a double blind vagina. The VACTERL and the MURCS associations are possible diagnoses. Her father had a neurenteric cyst in infancy. He has identical vertebral and costal malformations as his daughter but is otherwise healthy. The possibility of dominant inheritance with gonosomal mosaicism in the father is discussed.


Tightly linked polymorphic markers for fragile X syndrome and prenatal cytogenetic diagnostic experience. Linkage analysis using the polymorphic loci DXS369, DXS296, DXS297 and DXS306 was carried out on a cohort of 17 families segregating for fragile X syndrome. The observed recombination fractions at: DXS369 (Zmax = 3.02; theta = 0.06), DXS297 (Zmax = 2.92; theta = 0.0), DXS296 (Zmax = 3.82; theta = 0.0), DXA306 (Zmax = 4.55; theta = 0.05) confirm that these loci are tightly linked to FRAXA. Our experience in the cytogenetic analysis of 58 at risk pregnancies by chorionic villus or fetal blood sample examination documents a false negative rate in obligate carrier male pregnancies for CVS of 11% and for FBS of 3%.


Delayed replication of Xq27 in individuals with the fragile X syndrome. The timing of late replicating bands on the X chromosome has been studied in individuals with the fragile X [fra(X)] syndrome. Compared to controls both affected individuals and symptomless carriers of the syndrome show delayed replication of the Xq27 region as shown by 2 different methods. The implications of this finding are discussed in relation to the proposal [Laird et al., 1987] that the fraX syndrome is associated with a failure to reactivate the Xq27 band correctly after it has been inactivated in a female.


Oculoauriculovertebral anomaly: segregation analysis. Seventy-four families of probands with oculoauriculovertebral anomaly were evaluated, including 116 parents and 195 offspring. Relatives were examined to identify ear malformations, mandibular anomalies, and other craniofacial abnormalities. For segregation analysis using POINTER, selection of the sample was consistent with single ascertainment. Different population liabilities were used for probands and relatives, because affection was narrowly defined for probands and broadly defined for relatives. The hypothesis of no genetic transmission was rejected. The evidence favored autosomal dominant inheritance; recessive and polygenic models were not distinguishable.


CNS midline anomalies in the Opitz G/BBB syndrome: report on 12 Brazilian patients. We report on 12 Brazilian boys with the Optiz G/BBB syndrome associated with CNS midline anomalies, namely, Dandy-Walker anomaly (two patients), enlarged cisterna magna (four patients), enlarged 4th ventricle (four patients), and callosal a/hypoplasia (two patients). These signs clearly show the involvement of the CNS midline in the Opitz G/BBB syndrome.


Callosal agenesis, iris coloboma, and megacolon in a Brazilian boy with Rubinstein-Taybi syndrome. We report on a Brazilian boy with Rubinstein-Taybi syndrome (RTS) with callosal agenesis, iris coloboma, and megacolon. To our knowledge, callosal agenesis, iris coloboma, and megacolon are unusual signs within the clinical spectrum of RTS, and the present association is apparently underscribed.


Lacrimo-auriculo-dento-digital syndrome: evidence for lower limb involvement and severe congenital renal anomalies. We describe a 3-generation family with lacrimo-auriculo-dento-digital syndrome (LADD). In addition to the well described abnormalities of ears, teeth, lacrimal apparatus and digits, the patients exhibit several previously undescribed anomalies, including minor facial anomalies (broad forehead, telecanthus, bulbous nasal tip, full jaw, ptosis and flared nostrils), involvement of the first and second toes, and congenital renal disease causing death in the neonatal period in 2 cases.


Acrocallosal syndrome: report of a Brazilian girl. We report on a Brazilian girl born to nonconsanguineous parents and presenting with frontonasal dysostosis, callosal agenesis, abnormal upper lids, cleft lip/palate, redundant skin in the neck, grooved chin, and bifid thumbs. Major diagnostic criteria present in this patient are related to the acrocallosal syndrome. The clinical and major nosologic aspects of this condition are discussed.


Ophthalmological, skeletal, and cardiac abnormalities in sibs born to consanguineous parents: a new syndrome? We report on a sibship from a consanguineous couple consisting of one boy with anophthalmia, one boy with buphthalmos and multiple congenital skeletal, muscle, and cardiac abnormalities, and a stillborn girl with anophthalmia and cardiac and skeletal abnormalities. A possible new syndrome of autosomal recessive inheritance and variable expressivity is discussed, comparing this report with others.


Overlap between Majewski and hydrolethalus syndromes: a report of two cases. We present 2 unrelated fetuses with manifestations of both the hydrolethalus syndrome and the short rib-polydactyly syndrome, type Majewski. It is proposed that cases of hydrolethalus syndrome with short limbs constitute a separate type of lethal osteochondrodysplasia mimicking short rib-polydactyly syndromes.


King syndrome: a genetically heterogenous phenotype due to congenital myopathies. We report on a patient with myopathy, kyphoscoliosis, joint contractures, and a facial appearance consistent with King syndrome. Unlike other reported cases, our patient had hyperextensible joints, normal stature, and pectus excavatum. The cardiac ventricles, aorta, and pulmonary artery were dilated. Malignant hyperthermia did not occur under anaesthesia although there was a transient increase in CK levels. Muscle bulk and tone were significantly decreased but collagen and elastin fibres were normal. The variable clinical presentation of King syndrome suggests that the manifestations are caused by different congenital myopathies and in all cases there is probably an increased risk of malignant hyperthermia.


Clinical variability and genetic heterogeneity within the Acadian Usher population. A number of Usher syndrome (USH) families are found among the French-Acadians living in southwestern Louisiana. These families are descended from a few common ancestors, suggesting that USH may be homogeneous within this ethnic group. However, we report distinct phenotypic variability. Based on differences in psychomotor development and tests of auditory and vestibular function, Acadian individuals with both USH Type 1 and Type 2 can be identified. One additional family, with unusual findings, represents a third clinical phenotype. Linkage data strongly support these clinical observations.


Branchio-oto-renal syndrome: further delineation of an underdiagnosed syndrome. We report on a woman who was diagnosed with branchio-oto-renal (BOR) syndrome after 2 pregnancies complicated by oligohydramnios due to renal hypoplasia and agenesis. Both babies died neonatally of pulmonary hypoplasia. Histopathology of the temporal bones of the second child showed marked immaturity of the middle ear cleft, ossicles, facial nerve and canal, and cochlear nerve. Maternal renal ultrasound study was normal although intravenous pyelography indicated renal hypoplasia. The frequency of BOR syndrome among cases of recurrent fetal renal hypoplasia/dysplasia or agenesis is unknown, and parental renal ultrasonography may not identify a heritable renal defect. Investigations should include a family history, and examination of relatives to look for preauricular pits, lacrimal duct stenosis, and branchial fistulae and/or cysts. Hearing studies and IVP may be indicated.


New autosomal recessive syndrome of sparse hair, osteopenia, and mental retardation in Mennonite sisters. We report on 2 Mennonite sisters with a syndrome of sparse hair, osteopenia, mental retardation, minor facial abnormalities, joint laxity, and hypotonia. Their asymptomatic consanguineous parents (inbreeding coefficient F = 1/64) have 6 other offspring, 3 of whom died in infancy of type II osteogenesis imperfecta (OI), and 3 of whom are normal. We analyzed collagens synthesized by cultured fibroblasts from these 2 sisters and their parents and detected no major abnormalities. Results of chromosomal and metabolic evaluations including amino acid analysis of plasma, urine, and hair were unremarkable. A literature search and survey of a computerized syndrome identification database did not disclose an identical phenotype. The sisters bear superficial resemblance to several known syndromes which we excluded on clinical and/or biochemical grounds. We conclude that they represent a new autosomal recessive syndrome, distinct from type II OI and perhaps unique to the Mennonite population or to this particular family.


Weissenbacher-Zweymüller syndrome: a distinct autosomal recessive skeletal dysplasia. The Weissenbacher-Zweymüller syndrome (WZS) is defined as congenital neonatal rhizomelic dwarfism with metaphyseal widening of the long bones and vertebral coronal clefts. Catch-up growth after 2-3 years is one of the striking manifestations. It is generally thought that WZS is a neonatal expression of the Stickler syndrome, even though in the latter, myopia, retinal detachment and a progressive metaphyseal dysplasia are characteristics that are not found in WZS. A critical analysis of all published patients with WZS in addition to 5 patients in 3 new families, shows that the WZS is a distinct syndrome of delayed skeletal maturation, different from the Stickler syndrome, and inherited as an autosomal recessive trait. The recognition of its unique characteristics has important implications in genetic counseling.


Ullrich-Turner syndrome with a small ring X chromosome and presence of mental retardation. Since some patients with Ullrich-Turner syndrome (UTS) have mental retardation, we reviewed our experience to look for a high-risk subgroup. Among 190 UTS and gonadal dysgenesis patients with X chromosome abnormalities, 12 had mental retardation. All of the six (100%) with a small ring X were educable (EMI) or trainable mentally impaired (TMI) with more severe delay than expected in UTS. Among the 184 with other X abnormalities, only 6 had similar delays (2 from postnatal catastrophes), for a frequency of 3.3% mental retardation among those without a small ring X; only 2.2% of these had unexplained mental retardation. Polymerase chain reaction studies showed no Y-derived material in the 2 patients who were evaluated, and in situ hybridization confirmed X origin of the ring in the 6 subjects who were evaluated. We describe the phenotype of the 6 individuals with a small ring X, and an additional 2 patients with a small ring X who were identified outside the survey. The subjects with a small ring X comprised a clinically distinct subgroup which had EMI/TMI and shorter stature than expected in UTS. Seizures and a head circumference less than 10th centile were observed in half of the patients with a small ring X, and strabismus, epicanthus, and single palmar creases were present in more than half. A "triangular" face in childhood, pigmentary dysplasia, sacral dimple, and heart defects were also common. Neck webbing appeared to be less frequent than in 45,X. We hypothesize that the high risk of mental retardation in this form of the UTS results from lack of lyonization of the ring X due to loss of the X inactivation center. Excluding those with a small ring X, mental retardation is not significantly increased in patients with UTS.


Unrecognized pseudohyperkalemia as a cause of elevated potassium in patients with renal disease. Pseudohyperkalemia, defined as serum to plasma potassium difference of more than 0.4 mmol/l, occurs when platelets, leukocytes or erythrocytes release intracellular potassium in vitro, leading to falsely elevated serum values. Pseudohyperkalemia has been observed in myeloproliferative disorders [1], including leukemia [2] and infectious mononucleosis [3] as well as in rheumatoid arthritis [4]. We present 2 patients with renal disease and thrombocytosis in whom pseudohyperkalemia was recognized only after common therapeutic measures and/or dialysis failed to effect a decrease in serum potassium. In patients with renal disease and thrombocytosis, plasma as well as serum potassium should be routinely measured prior to instituting aggressive therapy or altering dialysis prescription in order to avoid potentially dangerous overtreatment with resulting hypokalemia.


Development of systemic lupus erythematosus in a patient on hemodialysis. A case of systemic lupus erythematosus (SLE) that developed 2 years after beginning hemodialysis is reported. The patient had not been given any drug implicated in the production of SLE. She had been treated with deferoxamine, an in vitro inhibitory of DNA synthesis. The difficulty of the diagnosis is emphasized. Clinical improvement after prednisone treatment was impressive. SLE may appear even in patients receiving hemodialysis, despite immunological depression derived from chronic uremia.


Compression of the left brachiocephalic vein by the innominate artery resulting in massive arm edema in a hemodialysis patient. We report case of extrinsic compression of the left brachiocephalic vein by the innominate resulting in massive edema of the arm in a patient with hemodialysis Gore-Tex graft. To our knowledge, such phenomenon has not been previously reported.


Successful resection of pheochromocytoma in a hemodialysis patient. A 45-year-old woman with a pheochromocytoma who had been on regular hemodialysis for 4 years and underwent successful surgery is described. Careful preoperative management, including the use of prazosin and weight control, was carried out to prevent severe intraoperative and postoperative cardiovascular complications. Prazosin was given at an initial dose of 0.5 mg/day, and the dosage was increased to 20 mg/day prior to surgery. The increase in intravascular volume led to a gain of 3 kg in body weight. No deterioration of the cardiovascular or respiratory function was caused by these maneuvers, and surgery was performed without significant complications except for a rapid rise of blood pressure during tumor resection. To our knowledge, only one similar case report could be found in the English literature.


Comparison between acetate and bicarbonate dialysis for the treatment of lithium intoxication. Lithium is used to treat manic-depressive disorders, but toxic side effects commonly occur. The preferred treatment of severe lithium intoxication is hemodialysis. No data, however, exist comparing the effectiveness of acetate to bicarbonate dialysis for the removal of lithium. We present a case of lithium intoxication treated with both. During acetate dialysis, lithium removal occurred exclusively from the extracellular fluid space, while during bicarbonate dialysis, lithium removal occurred equally from both the extracellular and intracellular fluid spaces. We hypothesize that acetate but not bicarbonate activates the sodium-hydrogen antiporter on cell membranes, and that lithium, substituting for sodium, is driven into cells. This may explain the rebound in lithium levels commonly noted after conventional dialysis. We recommend bicarbonate hemodialysis as the therapy of choice for severe lithium intoxication.


Immunoglobulin A nephropathy in a renal allograft of a black transplant recipient. Although IgA nephropathy (IgA N) is reportedly the most common form of primary glomerulonephritis worldwide, there is a very low incidence of IgA N in Black Americans, and IgA N in Black patients with renal allografts has not been reported. In this report, we present the case of a Black patient with endstage renal disease presumed secondary to hypertensive nephrosclerosis who developed nephrotic range proteinuria due to IgA N in a cadaveric renal allograft 2 years following transplantation. Biopsy of the allograft in the immediate post-transplantation period had revealed no evidence of IgA N. Chronic active hepatitis related to hepatitis C preceded the development of proteinuria by approximately 1 year, raising the possibility that IgA N in the renal allograft was secondary to the liver disease. The clinical and histological features of primary IgA N and IgA N secondary to liver diseases are discussed.


Whole blood serotonin levels are markedly elevated in patients on dialytic therapy. The normal range for whole blood serotonin levels in chronic renal failure patients has not been defined. As serotonin may be implicated in platelet abnormalities, hypo- and hypertension and itch in dialysis patients, serotonin whole blood levels were measured in a group of patients with chronic renal failure and/or who were dialysis dependent. The levels were elevated in 12 patients with moderate (mean serum creatinine 335 +/- 54 mumol/l) chronic renal failure (270 +/- 46 micrograms/l) compared to 11 normals (163 +/- 17 micrograms/l, p less than 0.05; quoted normal range less than 300 micrograms/l) but did not correlate with serum creatinine levels. There was a marked elevation in serotonin levels in dialyzed patients, including those on hemodialysis (polysulfone, n = 6, 747 +/- 234 micrograms/l; cuprophane membranes, n = 6, 708 +/- 198 micrograms/l), hemodiafiltration (n = 12, 695 +/- 130 micrograms/l) and especially peritoneal dialysis (n = 6, 1,148 +/- 162 micrograms/l). All results were significant (p less than 0.01) compared to normals and compared to the nondialyzed group (p less than 0.05). The level of serotonin decreased during hemodialysis regardless of the membrane used. There was no positive correlation of serotonin levels with pruritus or hypertension, although there was a negative correlation with systolic blood pressure. The reference range for serotonin whole blood levels needs to be broadened when considering dialyzed patients.


Early diagnosis of gram-negative peritonitis in continuous ambulatory peritoneal dialysis patients with the Lymulus amebocyte lysate assay. The treatment of peritonitis in continuous ambulatory peritoneal dialysis patients is empiric until the bacteriological results are available. The Lymulus amebocyte lysate assay (LAL) is a very sensitive method for the detection of endotoxin, a structural component of gram-negative bacteria. We performed the LAL assay in a prospective study in 36 consecutive episodes of peritonitis. The LAL assay was positive in all 10 episodes of gram-negative peritonitis (100% specificity). Treatment directed specifically against gram-negative or -positive infection was started based on the LAL assay result. In 26 episodes with LAL-negative test, a gram-positive bacterium was cultured in 23 episodes, in 1 there was fungal infection and 2 were sterile. In summary: the LAL assay is a rapid (1 h) and sensitive method for the differentiation of gram-positive or -negative peritonitis and enables starting an immediate and more appropriate antibiotic therapy.


Comparative study of IgA nephropathy with acute and insidious onset. Clinical, laboratory and pathological findings. In order to clarify the difference of clinical and pathological features between the IgA nephropathy patients with acute and insidious onset, 427 patients were examined in this study. Seventy-eight patients with acute onset (group 1) were often associated with mucosal system infections at the abrupt onset. This group revealed macroscopic hematuria, more severe microscopic hematuria (more than 20/hpf), higher glomerular filtration rate (p less than 0.01) and lower serum levels of C3 (p less than 0.01). It had also a significantly higher incidence of exudative lesions (p less than 0.001). On the other hand, the onset of 349 patients (group 2) was noticed to be insidious without preceding infections. This group showed a more severe increase in mesangial cells (p less than 0.01) and a significantly higher incidence of adhesion, arterial sclerosis and tubulointerstitial changes. Deposition of Clq, C4 and IgM and detachment of visceral epithelium from the basement membrane were more frequently seen in group 2. Twenty-seven of 345 patients followed for at least 1 year after the biopsy were on maintenance hemodialysis: 1 patient was in group 1 and 26 were in group 2. These results clarified that there was a difference in clinical, laboratory and histopathological findings between the patients with IgA nephropathy with acute and insidious onset.


Effect of dialyzer reprocessing with Renalin on serum beta-2-microglobulin and complement activation in hemodialysis patients. The peracetic acid-based sterilant Renalin is increasingly being used for reprocessing hemodialyzers. In order to evaluate the effects of reprocessing on beta 2-microglobulin (beta 2M) kinetics and complement activation in chronic hemodialysis patients, we compared 4 dialyzer membranes on 1st, 2nd and 4th use of the membrane. Dialysis with new cuprammonium rayon dialyzers (0.8 m2) for 4 h resulted in a nonsignificant increase in serum beta 2M concentrations of 10.7% (corrected for changes in extracellular volume) and significant generation of the complement component C3a des Arg. On reuse, minimal changes in serum beta 2M levels were noted and complement activation was absent. Dialysis with new cellulose acetate (CA, 1.5 m2), polyacrylonitrile (AN69 HF, 1.6 m2) or polymethylmethacrylate (PMMA, 1.6 m2) membranes resulted in significant decreases in serum beta 2M levels (19.5, 31.7 and 50.8%, respectively). Reprocessing had negligible effects on the removal of beta 2M by CA and AN69, but by the 4th use halved the effectiveness of PMMA. Reprocessing reduced the significant generation of C3a des Arg observed with new CA and PMMA membranes. We conclude that, except for PMMA, Renalin reprocessing has minor effects on the ability of the membranes to remove beta 2M and improves the biocompatibility of all membranes studied.


Effect of erythrocyte deformability on renal hemodynamics and plasma renin activity. Increased blood viscosity has been previously noted in a subgroup of patients with essential hypertension with concomitant high plasma renin activity (PRA). It has been suggested that the cause of hyperviscosity in hypertensives is the presence of circulating red blood cells (RBCs) that were rendered less deformable by significant alterations in their cationic milieu, namely an increase in intracellular concentration of calcium and sodium. The relation between RBC deformability and PRA however is not clear. Our study was conducted to examine this issue. RBC deformability was reduced experimentally, and its effects on renal blood flow, renal artery resistance, glomerular filtration rate and PRA were investigated in experimental (n = 8) and control (n = 4) groups of dogs. Blood was collected from the animals before the experiments and incubated with 0.025% glutaraldehyde. These hardened RBCs were administered to the animals through exchange transfusions. Following the exchange transfusion with the hardened RBCs, there were no changes in renal blood flow, renal artery resistance, and the creatinine clearance. The only change observed was an increase in PRA. In the control group, all parameters that were determined remained unchanged. The data are consistent with the notion that the presence of circulating hardened RBCs may by itself increase PRA, and this effect can be important in some types of hypertension and some other disorders in which impaired deformability of RBCs have been reported.


Volumetric analysis of urinary erythrocytes: a standardized methodology to localize the source of haematuria. Volumetric analysis of urinary red blood cells (RBCs) was performed in two groups of patients: (a) 91 with glomerulonephritis (GN), 158 with non-glomerular diseases (non-GN) and 53 controls without haematuria; (b) 97 with GN and 41 with non-GN diagnoses and greater than or equal to 2+ haematuria, analysed after modified sample preparation (isotonic dilution and haemolysis to eliminate non-RBC debris). In group A, diagnostic ranges were established for modal, mean and differential (urinary-peripheral blood modal) RBC volumes to differentiate GN from non-GN sources of blood loss according to RBC size. 54% (135/249) of modal volumes and 68% (124/183) with greater than or equal to 2+ haematuria were within a diagnostic range of values, i.e. 40-180 fl (sensitivity), and the source of haematuria was correctly identified in 85% (115/135) and 87% (108/124) of these, respectively (specificity). Of the remainder, with modal volumes less than 40 or greater than 180 fl, 45% (51/114) were from GN and 55% (63/114) from non-GN specimens, along with 94% (48/53) controls without haematuria (non-diagnostic analyses). In contrast, whilst 90% (74/82) of mean volumes greater than or equal to 110 fl and 94% (62/66) of differential volumes greater than or equal to 0 fl were from non-GN specimens, values below these were common to both diagnostic groups so that diagnostic sensitivities were reduced to 38% (82/219) and 34% (66/193), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)


Fractional excretion of urea as a guide to renal dysfunction. The use of fractional excretion of sodium as a guide to renal perfusion is hampered by the prior use of natriuretic agents. The fractional excretion of urea (FEUr) has been shown to be affected by volume status. We, therefore, determined the value of the FEUr as a guide to renal perfusion. In 6 patients evaluated prospectively and in 87 patients evaluated retrospectively, a low FEUr (less than or equal to 35%) was found to be a sensitive index to renal perfusion, despite the prior administration of furosemide.


Once weekly versus twice weekly subcutaneous administration of recombinant human erythropoietin in haemodialysis patients. Optimal route and frequency of administration of recombinant human erythropoietin (rHuEPO) have not yet been determined. There is some evidence to suggest that subcutaneous administration of rHuEPO may be more effective than the intravenous route in reversing renal anemia. It is also unclear whether rHuEPO is more effective when given by a large intermittent dose or by more frequent multiple divided doses. We have compared the effect of twice weekly versus once weekly subcutaneous administration of rHuEPO in two groups of haemodialysis patients. At the end of 12 weeks of treatment with rHuEPO, the mean haemoglobin levels had risen from 6.9 +/- (SD) 0.7 to 8.9 +/- 1.3 g/dl in the once weekly group and from 7.2 +/- 1.0 to 9.3 +/- 1.6 g/dl in the twice weekly group. The average doses of rHuEPO used during the study were 127 +/- 6 and 115 +/- 18 U/kg body weight/week for the once weekly and twice weekly groups, respectively. Subcutaneous administration of low-dose rHuEPO is effective in reversing renal anaemia. Similar responses were obtained with once weekly and twice weekly regimens.


Effect of amino acid based dialysis solution on peritoneal permeability and prostanoid generation in patients undergoing continuous ambulatory peritoneal dialysis. The acute effect of amino acid based dialysis solution on peritoneal kinetics of amino acids and plasma proteins in comparison to conventional glucose-based dialysate was studied in 9 patients with end-stage renal failure on continuous ambulatory peritoneal dialysis. Instillation of 2.6% amino acid solution resulted in raised plasma concentrations of all essential amino acids included in the dialysis fluid (p less than 0.005). The amino acid solution induced an augmented leakage of plasma proteins into the dialysate at all dwell times investigated (1-8 h). After a dwell time at 8 h, the dialysate total protein increased from 2.62 +/- 0.45 g with glucose dialysate to 3.85 +/- 0.42 g with amino acid solution (p less than 0.05). Corresponding results were obtained for beta 2-microglobulin, albumin, transferrin, IgG, and for the non-essential amino acids alanine, citrulline, and glutamine (p less than 0.025) not included in the initial amino acid composition of the dialysis fluid. During the use of amino acid based dialysis fluid, the effluent prostaglandin E2 concentration increased by more than 80% in comparison to glucose dialysate (p less than 0.025). The augmented loss of proteins induced by the amino acid solution was positively correlated with increased dialysate prostaglandin E2 (r = 0.8894; p less than 0.001). Peritoneal ultrafiltration was not affected by the use of amino acid based dialysate fluid. The present results indicate that amino acid based dialysis fluid enhances the peritoneal permeability for plasma proteins and amino acids, probably mediated by locally generated prostanoids.


Pain at the injection site of subcutaneously administered erythropoietin in maintenance hemodialysis patients: a comparison of two brands of erythropoietin. Local pain due to subcutaneous erythropoietin (EPO) injection into the thigh was studied using a verbal score ranging from 0 to 4. Equivoluminous doses of epoetin-alpha (Cilag) and epoetin-beta (Boehringer) were compared in 2 controlled single-blind experiments: 10 dialysis patients were treated at random for 4 weeks at consecutive sessions with both brands of EPO, and 40 patients were treated in 1 session only with the 2 brands simultaneously. Pain scores were 1.12 +/- 0.28 versus 0.15 +/- 0.06 (p less than 0.05) and 1.75 +/- 0.19 versus 0.08 +/- 0.04 for epoetin-alpha and epoetin-beta, respectively (p less than 0.001). Treatment acceptance was 48% for epoetin-alpha versus 83% for epoetin-beta (p less than 0.05).


Abnormalities of thirst regulation in patients with chronic renal failure on hemodialysis. To determine whether thirst mechanisms are altered in nondiabetic patients with chronic renal failure on hemodialysis, 4 patients with an average weight gain between dialysis sessions of more than 5% of dry body weight (group I), 5 patients with less than 3% weight gain (group II), and a group of 6 healthy subjects (group III) were submitted to infusion of hypertonic saline. After infusion the subjects had free access to water. Thirst was evaluated by visual analogue rating scales. Despite similar increments of effective plasma osmolality during saline infusion, patients of group I were thirstier than groups II and III (p less than 0.005 and p less than 0.01, respectively). Changes in thirst ratings were similar in groups II and III. Osmotic thresholds for thirst onset were similar in groups II and III (288.9 +/- 8.5 and 289.8 +/- 3.4 mosm/kg, respectively), but lower in group I (277.6 +/- 7.6 mosm/kg). Nevertheless, great variations were observed in the latter group. Thus, 2 patients showed thresholds for thirst within the normal range, whereas the others had low osmolar thresholds for thirst and baseline plasma osmolalities and high basal thirst scores. During the drinking period, the patients of group I drank more (14.2 +/- 2.8 ml/kg) than those of groups II (5.3 +/- 1.6 ml/kg; p less than 0.02) and III (10.2 +/- 1.6 ml/kg; n.s.) The plasma levels of angiotensin II in uremic patients were higher than in healthy subjects, although there were no differences between groups I and II and no correlation between basal angiotensin II levels and the interdialytic weight gain.(ABSTRACT TRUNCATED AT 250 WORDS)


Inhibition of cytokine synthesis by peritoneal dialysate persists throughout the CAPD cycle. The current study focused on the effect of continuous ambulatory peritoneal dialysis (CAPD) dialysate obtained following different intraperitoneal dwell periods on the release of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF alpha) from mononuclear leukocytes (PBMC). Aliquots of 5 x 10(6)/ml healthy peripheral PBMC were exposed to fresh or spent CAPD dialysate (10-240 min of intra-peritoneal dwell) and stimulated with Escherichia coli endotoxin (10 micrograms/ml, 2h). IL-6 and TNF alpha in cell supernatants were determined by specific enzyme immunoassays. Control PBMC in physiological buffer released 361 +/- 70 pg/ml IL-6 and 717 +/- 147 pg/ml TNF alpha (mean +/- SEM, n = 8), whereas exposure to fresh dialysis fluids severely suppressed cytokine release from PBMC (less than 30 pg/ml IL-6 and less than 15 pg/ml TNF alpha). A significant inhibition of IL-6 and TNF alpha release was also observed in PBMC exposed to spent dialysate. The inhibitory capacity of the spent fluids was pronounced with increasing intra-peritoneal dwell time (10 min: 183 +/- 45 pg/ml IL-6 and 538 +/- 109 pg/ml TNF alpha; 240 min: 26 +/- 5 pg/ml IL-6 and 105 +/- 30 pg/ml TNF alpha; mean +/- SEM, n = 16). These data indicate that the impairment of cell responsiveness following exposure of PBMC to peritoneal dialysate is not restricted to the unused fluids, but is also observed following intra-peritoneal equilibration. Moreover, our findings suggest the presence of cytokine inhibitory factors in the peritoneal dialysate of CAPD patients which appear to accumulate in the peritoneal effluent during the CAPD cycle.


Effect of hypercalcemia on renal sympathetic nervous system activity. Since calcium plays a modulatory role in the activity of the sympathetic nervous system (SNS), in these studies, we have tested the hypothesis that hypercalcemia may alter renal SNS activity, and, consequently, renal function. Acute hypercalcemia was induced in Sprague-Dawley rats by infusion of calcium 30 mg/kg/2 h in 0.45% saline. A control group of rats received only 0.45% saline. Two more groups of rats received either calcium or 0.45% saline 7-10 days after total renal denervation. Calcium infusion increased serum calcium by 1.8 +/- 0.23 mg/dl in rats with intact renal nerves and by 2.7 +/- 0.48 mg/dl in renal denervated rats. Mean arterial pressure and inulin clearance did not change during calcium or 0.45% saline in rats with intact renal nerves. Renal sympathetic nerve activity (RSNA) decreased by 44% in rats infused with calcium, but it did not change in control animals. Calcium caused a significantly greater rise in urine volume, sodium excretion and fractional excretion of sodium than the infusion of 0.45% saline. Rats with renal denervation manifested greater baseline urine volume, sodium excretion and fractional excretion of sodium than rats with intact renal nerves. Infusion of calcium, however, caused no further rise in urine sodium excretion in these animals. alpha-Methyltyrosine, an inhibitor of norepinephrine (NE) synthesis, also increased natriuresis in rats. Calcium reduced by 27% the NE content in the kidney but not in the heart. Methyltyrosine, on the other hand, reduced NE content in both the heart and the kidney.(ABSTRACT TRUNCATED AT 250 WORDS)


Uremic inhibitors of erythropoiesis: a study during treatment with recombinant human erythropoietin. The effects of increasing amounts of uremic sera (US) on the growth of erythroid progenitor cells [burst-forming unit erythroid (BFU-E)] collected from peripheral blood of normal subjects were evaluated to assess the potential role of uremic inhibitors of erythropoiesis during a treatment with recombinant human erythropoietin (r-HuEpo). US were collected from 8 patients on regular dialysis with marked anemia (Hb 6 +/- 0.5 g%) before and after a treatment with high doses of r-HuEpo (from 300 to 525 U/kg/week). Standard cultures for BFU-E were performed in alpha-metylcellulose with fetal calf serum (FCS) and 4 U/ml of r-HuEpo (Cilag, Ortho). In successive cultures, US were added at increasing amounts to the standard culture in order to assess a possible inhibitory effect on BFU-E growth. Finally, in order to assess a possible lack of stimulatory factors, we partially substituted FCS with US. The addition of US collected either before or after therapy with r-HuEpo to the standard culture had no effect on the growth of BFU-E. Vice versa, the number of cultured BFU-E decreased when FCS was partially substituted with US collected before r-HuEpo. This effect was not evident when FCS was partially substituted with US collected after r-HuEpo. No significant differences were recorded in the tested sera collected before and after therapy considering erythropoietin levels and amino acid levels. We hypothesized that some other factors with erythropoietic stimulatory activity (burst-promoting activity?) may be deficient in uremic patients with marked anemia and can be induced during therapy with r-HuEpo.


Long-term immunogenicity and efficacy of hepatitis B vaccine in hemodialysis patients. Although the efficacy of hepatitis B vaccines in patients under chronic hemodialysis treatment has been well documented, the persistence of immunity in this population remains largely unknown. In this study we have followed 60 hemodialysis patients up to 3 years after primary hepatitis B vaccination (four doses of recombinant hepatitis B vaccine; Engerix B, 20 mg/dose) to evaluate the persistence of immunity (as indicated by serum levels of antibody to hepatitis B surface antigen-anti-HBs-higher than or equal to 10 mIU/ml). Fourty-four (73%) patients developed anti-HBs levels above 10 mIU/ml after vaccination; the remaining 16 (27%) vaccinees were considered nonresponders and were given a booster dose that again failed to elicit an immunoresponse. After 3 years of follow-up, 18 out of 44 (41%) responders had no detectable anti-HBs levels in the serum (antibody loss occurring within 8 and 12 months in 3 cases, within 1 and 2 years in 13, and within 2 and 3 years in 2 other cases). When compared with the responders that lost their antibodies during the follow-up period, those who remained immunoreactive 3 years after vaccination was initiated were younger and had higher anti-HBs levels at 8 months of follow-up. Two hepatitis B virus infections were detected among nonresponders during the follow-up period. Based on these data, we conclude that patients undergoing chronic hemodialysis therapy not only have lower response rates to hepatitis B vaccination than healthy adults, but also that these are frequently transient.(ABSTRACT TRUNCATED AT 250 WORDS)