Localization of a 210-kDa microtubule-interacting protein in the yeast Saccharomyces cerevisiae. Using the monoclonal antibody MA-01, which recognizes a 210-kDa protein in cell-free extracts, spindle and cytoplasmic microtubules were visualized in budding yeast, Saccharomyces cerevisiae. In additional, a spot-like staining was found beneath the plasma membrane, revealing in part correlation with F-actin distribution. This pattern was common for cells of all cell-cycle stages. The interaction of the protein recognized by MA-01 with microtubules was confirmed in the double labeling with a polyclonal antitubulin antibody and by the sensitivity of intranuclear structures stained by MA-01 to the microtubule disrupting drug nocodazole.


Purification of an enterotoxin produced by Bacillus cereus by immunoaffinity chromatography using a monoclonal antibody. A murine monoclonal antibody (MAb) with high reactivity to an enterotoxin produced by Bacillus cereus was used to prepare an immunoadsorbent for purification of the enterotoxin. By immunoaffinity chromatography using the immunoadsorbent, approximately 25% of crude enterotoxin applied was recovered in the eluate. The purified enterotoxin was found to be electrophoretically and antigenically homogeneous. It also showed vascular permeability activity and mouse lethality, and caused fluid accumulation in mouse ligated intestinal loops, whereas it did not show any hemolytic and lecithinase activities. Thus, immunoaffinity chromatography proved useful in the purification of enterotoxin produced by B. cereus in terms of recovery, purity, and relative ease of performing the purification.


Competition among Rhizobium leguminosarum bv. phaseoli strains for nodulation of common bean. Six effective Rhizobium leguminosarum bv. phaseoli strains were examined for nodulation competitiveness on common bean (Phaseolus vulgaris L.), using all possible two-strain combinations of inoculum. Nodule occupancy was determined with strain-specific fluorescent antibodies. The strains were divided into three groups according to their overall competitive abilities on pole bean cv. Kentucky Wonder and bush bean cv. Bountiful. Strains TAL 182 and TAL 1472 were highly competitive (greater than 70% nodule occupancy); strains KIM-5, Viking 1, and CIAT 899 were moderately competitive (approximately 50% nodule occupancy); and strain CIAT 632 was poorly competitive (less than 5% nodule occupancy). The competitiveness of the six strains was similar on the two host cultivars. The proportion of competing strains in the inoculum influenced the nodule occupancy of the highly competitive and moderately competitive strains, but not that of the poorly competitive strain. Two outstanding strains (TAL 182 and TAL 1472) were identified as ideal model strains for molecular and genetic studies on nodulation competitiveness.


Plasmids in Listeria monocytogenes and other Listeria species. One hundred and twenty-two food, clinical, and veterinary strains of Listeria monocytogenes were examined for the presence of plasmids. Twenty-five (20%) contained plasmids, which varied from 1.3 to 66 MDa in size. Of 10 strains of other Listeria species (L. innocua, L. ivanovii, L. welshimeri, L. seeligeri, L. grayi, and L. murrayi) examined, seven (70%) contained plasmids, varying from 38 to 53 MDa. No strains with multiple plasmids were found. Plasmids of identical size were isolated from related strains in some, although not all, cases. The presence of a plasmid in a strain was not related to phenotypic characters of known extrachromosomal inheritance.


O-acetylated peptidoglycan: its occurrence, pathobiological significance, and biosynthesis. Bacterial cell walls and their structural units, particularly peptidoglycan, induce a vast variety of biological effects in host organisms. The pathobiological effects of peptidoglycan are greatly enhanced by various modifications and substitutions to its basic composition and structure. One such modification is the presence of acetyl moieties at the C-6 hydroxyl group of N-acetylmuramyl residues, and to date, 11 species of eubacteria, including some important human pathogens, such as Neisseria gonorrhoeae, Proteus mirabilis, and Staphylococcus aureus, are known to possess O-acetylated peptidoglycan. This review addresses the influence of O-acetylation of peptidoglycan on its resistance to degradation both in vitro and in vivo, the clinical importance of the modification, and the currently held views on the pathway for its biosynthesis.


Laboratory investigation of virulence among strains of Yersinia enterocolitica and related species isolated from pigs and pork products. Eighty strains of Yersinia enterocolitica and related species isolated from slaughtered pigs and pork products were tested for possession of virulence-associated phenotypes by employing 12 in vivo and in vitro assays. The isolates could be broadly divided into two groups: (i) strains belonging to pathogenic bioserotypes of Y. enterocolitica that displayed virulence-associated characteristics in most or all assays and (ii) strains belonging to Y. enterocolitica biotype 1A and to related species that were largely negative in these assays. No individual test was found as a single reliable measure of virulence. All strains belonging to Y. enterocolitica serotype O:1,2,3 were pyrazinamidase positive (indicates avirulence) and autoagglutination negative but were positive in all other virulence assays. Salt aggregation was found to be a better indicator of virulence than latex particle agglutination, both of which measure surface hydrophobicity. Overall, tissue culture cell invasion provided the best selection of a subpopulation of yersiniae that are potentially virulent. However, crystal violet and Congo red binding assays among others provided good prediction of virulence at the time of testing. Our results provide further evidence that swine may constitute an important reservoir of human pathogenic strains.


Growth morphology of Streptomyces akiyoshiensis in submerged culture: influence of pH, inoculum, and nutrients. Most media in which the growth of shaken submerged cultures of Streptomyces akiyoshiensis was examined did not support the formation of well-dispersed mycelial suspensions. Investigation of the culture conditions promoting dispersed growth showed the pH of the culture medium to be of critical importance; an initial value of 5.5 minimized aggregation of the mycelium while supporting adequate biomass production. In cultures started at this pH, spore inocula gave better mycelial dispersal than did vegetative inocula; with spore inocula, growth morphology was also less affected by inoculum size. The composition of the nutrient solution influenced the extent of mycelial dispersal; slow growth was often associated with clumping but no clear correlation was observed between pellet formation and the ability of carbon or nitrogen sources to support rapid growth. Increasing the phosphate concentration from 0.5 to 15 mM caused a modest decrease in mycelial aggregation. Conditions promoting a well-dispersed mycelium suitable for studying the physiological control of secondary metabolism also supported the formation of 5-hydroxy-4-oxonorvaline by S. akiyoshiensis.


Low-dose steroid therapy in cyclosporine-treated renal transplant recipients with well-functioning grafts. The Canadian Multicentre Transplant Study Group. Low-dose prednisone given on alternate days as a steroid adjunct to cyclosporine therapy was investigated primarily for its influence on kidney graft and patient survival and, secondarily, on renal function and complications. Multicentre randomized double-blind clinical trial. Fourteen Canadian transplant centres. A total of 523 patients with well-functioning renal transplants (cadaveric grafts or grafts from living related donors) and without active graft rejection reactions who were entered into the trial from 1982 to 1985. Patients were randomly assigned 90 days after transplantation to receive either placebo (260 patients) or low-dose prednisone (263 patients). Graft and patient survival. After at least 5 years of follow-up 50 patients assigned placebo had lost their graft and 17 had died; the corresponding figures for those assigned prednisone were 38 and 16. After an average interval of 1.4 years 143 patients in the placebo group and 123 patients in the prednisone group had stopped therapy with the test drug or had had their treatment group decoded or both. Patients were withdrawn from the study 2 years after stopping the test therapy. The actuarial 5-year graft survival rates were 73% and 85% in the placebo and prednisone groups respectively (p = 0.03), and the actuarial 5-year patient survival rates were 92% and 94% respectively (p = 0.6). This analysis included 43 and 29 graft losses and 14 and 12 deaths in the placebo and prednisone groups respectively. Weibull parametric modelling of graft survival identified the following variables as risk factors for graft loss: histocompatibility leukocyte antigen B (HLA-B) mismatching (p = 0.007), donor death from cerebrovascular accident (p = 0.01), increased donor age (p = 0.02) and being a male recipient (p = 0.05). When these factors were included in the Cox proportional hazards model, the influence of assigned treatment on graft survival was reduced to p = 0.1. Donor death from cerebrovascular accident (p = 0.002), diabetes mellitus in the recipient (p = 0.02) and increased recipient age (p = 0.05) were risk factors for patient death. Renal function and incidence of complications were similar in the treatment groups. Continued administration of low-dose prednisone on alternate days is advisable, particularly in patients with cadaveric grafts and those with previously failed transplants.


Effect of nonmedical factors on family physicians' decisions about referral for consultation. To identify nonmedical factors perceived by family physicians (FPs) and consultants as important influences on decisions about referral for consultation, to determine the relative frequency with which such factors are cited and to identify those factors ranked as most important by the FPs and consultants. Survey with semistructured interview between July 1989 and April 1990. A total of 41 FPs and 20 consultants who were practising or had practised previously in Nova Scotia. The questionnaire comprised 10 questions: 4 were nondirective "probes" designed to elicit responses without suggesting possible answers, 2 asked the participants to rank such responses in order of importance, and 4 were "prompts" that asked for comments about a list of factors based on a review of the literature. A total of 4845 discrete items were mentioned as being capable of influencing FPs' decisions about referral for consultation. Aggregation of related items resulted in a list of 35 nonmedical factors, of which 11 were identified by at least half the respondents and 14 by less than half but more than 10. These 25 factors fell into three categories: patient and family factors (e.g., patient's wishes), FP and consultant factors (e.g., FP's capabilities), and other influences (e.g., style of practice). On the basis of both frequency of identification and priority scores "patient's wishes" emerged as the most important factor. Two medical factors that were consistently cited--type of problem and age of patient--were thought to interact with the other factors. Certain nonmedical considerations may substantially affect physicians' referral practices.


Enhanced expression of stomach cancer antigen derived from malignantly transformed bloom syndrome cells previously labeled with bromodeoxyuridine. Bromodeoxyuridine (BrdU) greatly enhanced expression of stomach (ST) cancer antigen (CA) that originated from a malignantly transformed Bloom syndrome (BS) cell line (BS-SHI-4M), although the expression was suppressed with a decrease in sister chromatid exchange (SCE) in the presence of deoxythymidine (dT) or deoxycytidine (dC) and enhanced with an increase in SCE with deoxyguanosine (dG) or deoxyadenosine (dA). Although the exact mechanisms for enhancing CA by BrdU treatment are unknown, these findings appeared to be of special interest because of the parallelism of CA expression and SCE alterations. The finding that BrdU enhancement of the ST CA was effective not only in the immunofluorescence (IF) protocol but also in the band appearance of Western blotting would be worthwhile as a sensitive serodiagnosis of cancer. The 118-kd band obtained from proteins of ST CA cells previously labeled with BrdU was clearly more darkly stained than that from nonlabeled cells and enabled eight weak-positive ST CA to show strong-positive levels retaining complete negativity to nonmalignant sera. Some ST cancer sera (advanced cancer), which originally gave a negative reaction in the nonlabeled condition, still inhibited negative reaction even in BrdU-labeled ST CA cells, however. The inability to detect cancer antibody in our assay might be due to immunocomplexes. Acid dissociation and ultrafiltration of sera from six of seven advanced ST cancers (originally IF negative) have allowed detection of antibody responses to ST CA by Western blot assay with enhanced reactivity as compared with the negativity under native serum conditions. This technique provides a reasonable avenue for study of the mechanisms of CA expression and serodiagnosis.


Two karyotypically unrelated clones with the t(5;17) and deletion of 5q in myelodysplastic syndrome. We report a patient with primary myelodysplastic syndrome (MDS) and two coexisting karyotypically independent clones. Cytogenetic investigation of bone marrow (BM) cells at diagnosis showed, besides the cells with normal karyotype, a clone that manifests an interstitial deletion of the long arm of chromosome 5 and a second one with a t(5;17). The rarity of finding a BM mosaicism in myelodysplasia with 5q- in some cells and different chromosomal abnormalities in others may be considered to support the multistep theory of pathogenesis in MDS.


A case of lipoblastoma with t(3;8)(q12;q11.2). We studied a single case of lipoblastoma in a 4-year-old boy. Cytogenetic analysis of the tumor cells showed two abnormal clones: 47,XY,t(3;8)(q12;q11.2),+mar, and 46,XY,t(3;8)(q12;q11.2). To our knowledge, this is the second report of chromosome findings in this rare tumor. Although lipoblastomas are frequently confused with myxoid liposarcomas, breakpoints in our patient were different from those of myxoid liposarcoma.


The activated human c-Ha-ras-1 oncogene as a mutagen. The induction of gene mutations and chromosome aberrations by plasmid pEJ6.6 carrying the activated c-Ha-ras-1 oncogene from human bladder carcinoma was studied in cultured Chinese hamster cells. Both an increase in the frequency of hypoxanthine-phosphoribosyltransferase-deficient (HPRT-) mutants and chromosome aberrations was observed after pEJ6.6 transfection as compared to control series (pBR322). In order to define whether it is the oncogene which is responsible for the mutagenic effect of pEJ6.6, a derivative of c-Ha-ras-1 carrying a deletion in its coding region was constructed. As shown in all experiments, the frequency of HPRT- mutants after treatment with pEJ6.6 plasmid exceeded that in control dishes treated by pEJ6.6 plasmid with an inactivated oncogene. The effect was rather weak but statistically significant. Thus, the results of experiments carried out show that the mutagenic activity of pEJ6.6 plasmid is chiefly determined by its oncogene. The role of the mutagenic effects of activated oncogenes in malignant transformation is discussed.


Chromosome number correlates with survival in patients with malignant pleural mesothelioma. Modal (MO) and mean (ME) chromosome numbers determined by cytogenetic analysis were compared with survival in 34 patients with diffuse malignant pleural mesothelioma. The patients with normal chromosome number and no clonal abnormalities (MO = 46) survived longer (median survival 17 months) than patients with clonal abnormalities. MO greater than 46 correlated with shorter survival (median 12 months) (p = 0.0186). The correlation was more clear between mean chromosome number (ME) and survival: the median survival of patients with ME greater than 46 was 13 months whereas that of the patients with ME less than 46 was 26 months and ME = 46 (normal chromosome number and no clonal abnormalities) 31 months (p = 0.0007). Furthermore, there was a tendency of an association between ME = 46, ME less than 46 and epithelial subtype reported to be associated with a favorable prognosis in mesothelioma. The addition of chromosome material may present a mechanism to enhance expression of genes important in the pathogenesis of mesothelioma and lead to more aggressive behavior of the tumor.


Cytogenetic biclonality in malignant hematologic disorders. Generally, malignant hematologic disorders have been believed to be of monoclonal origin. However, cytogenetically unrelated clones have been reported in some disorders including one case of acute leukemia (AL), one of acute lymphoblastic leukemia (ALL), one of acute myeloblastic leukemia (AMMoL), and five of myelodysplastic syndromes (MDS). The most frequent chromosome abnormality was trisomy 8 (75%), followed by trisomy 21 (37.5%, including tetrasomy 21) and trisomy 11 (25%). Two patients showed both trisomy 8 and 11, one also had trisomy 21 (triclonal). One patient showed two cytogenetically distinctive clones in which one was 47,XY,+8, related to myeloid cells, and the other had a del(6q) and del(9p), suggesting lymphoid cells. One patient we report and 5 from the literature had two unrelated clones with trisomy 8 and deletion of the long arm of chromosome 5 (5q-); all had MDS. Review of our records showed that 11 patients with both trisomy 8 and 5q- in the same abnormal karyotype (not biclonal) had AL, i.e., 10 of acute nonlymphocytic leukemia (ANNL) and one of chronic myelogenous leukemia (CML) in blastic crisis. These findings suggest that cytogenetically unrelated clones may indicate hematopoietic biclonality.


Uterine leiomyoma cytogenetics. III. Interphase cytogenetic analysis of karyotypically normal uterine leiomyoma excludes possibility of undetected trisomy 12. Uterine leiomyoma, a benign tumor that histopathologically is rather homogeneous, was recently characterized cytogenetically. About 40% of the investigated tumors are associated with clonal chromosome abnormalities and five different subgroups have been identified, characterized by trisomy 12, t(12;14)(q14-15;q23-24), del(7q), t(1;2)(p36;p24), and 6p rearrangements. In our survey of 76 cases, trisomy 12 was observed in 10% of the abnormal cases. To exclude a possible underscoring of this abnormality, we reexamined 15 of the cases with normal karyotype by interphase cytogenetics using a chromosome 12 alphoid DNA probe.


Recurrent chromosome aberrations in abdominal smooth muscle tumors. Short-term cultures of four abdominal smooth muscle tumors, three leiomyosarcomas and one leiomyoma, were analyzed cytogenetically. A low-grade malignant, epithelioid leiomyosarcoma had a normal karyotype. The other two leiomyosarcomas had abnormal karyotypes; one was near-diploid, and the other was near-triploid. Structural rearrangements of the short arm of chromosome 16 and monosomies of chromosomes 14, 15, and 22 were observed in both tumors. When our cases and previously published abdominal leiomyosarcomas are viewed in conjunction, loss of chromosomes 14, 15, and 22 are the most frequent abnormalities. The leiomyoma, the second cytogenetically abnormal nonuterine leiomyoma reported to date, had a hyperdiploid karyotype with a chromosome number of 56 and structural rearrangements of chromosomes 9, 14, and 19. The only aberrations similar to those observed in the previously reported esophageal leiomyoma were trisomies of chromosomes 7 and 8.


Deletion 12p in de novo acute myeloid leukemia. An association with early progenitor cell. Deletion of the short arm of chromosome 12 as the sole karyotypic abnormality was found in three cases of acute myeloblastic leukemia (AML). In contrast to what has previously been reported in the literature, none of our cases had an antecedent history of myelodysplasia or toxic exposure, and basophilia was absent. Two cases were terminal deoxynucleotidyl transferase (TdT) positive, suggesting involvement of an early progenitor cell.


Ring chromosome in parosteal osteosarcoma. Clinical and diagnostic significance. In this study, two specimens of a parosteal osteosarcoma, a rare primary bone neoplasm comprising only 3-6% of all osteosarcomas, were cytogenetically analyzed utilizing standard techniques. In contrast to the complex karyotypes previously reported in osteosarcoma, this particular histologic subtype was characterized by a single chromosomal aberration, a ring chromosome. Ring chromosomes have been described as characteristic for two other low-grade malignant mesenchymal neoplasms, well-differentiated liposarcoma and dermatofibrosarcoma protuberans. We propose that the observation of a ring chromosome in osteosarcoma also correlates with a low-grade malignant potential.


Sister chromatid exchange and chromosome breakage in complete hydatidiform moles. Women with complete hydatidiform moles (CHM) are at a 10% risk for developing persistent trophoblastic disease or choriocarcinoma. We studied sister chromatid exchange (SCE) as a prognostic indicator for malignancy in peripheral blood lymphocytes (PBL) from women with CHM and their husbands, but found no differences from normal control couples. SCE levels in cultured tissue derived from 11 CHM (avg. 7.9) and 2 choriocarcinomas (avg. 6.8) were not significantly different from those of 8 normal skin fibroblast cultures (avg. 7.8). These same tissues were then examined for chromosome breakage which was significantly higher for CHM (0.48/cell) and choriocarcinoma (0.87/cell) than normal fibroblasts (0.33/cell). Chromosome breaks occurred at 50-60% known fragile sites and at 50-55% of cancer breakpoints. Whereas SCE was only associated with 13% of breaks in the three tissues, half of these were at known fragile sites. Our results suggest that SCE is not an indicator of malignancy in PBL or cultured cells from CHM or choriocarcinoma and that the level of SCE is not elevated in CHM or choriocarcinoma. However, our results confirm the increased breakage seen in the latter two tissues which may represent general DNA instability predisposing to choriocarcinoma and its accompanying chromosomal rearrangements.


Genetics and biology of human ovarian teratomas. III. Cytogenetics and origins of malignant ovarian germ cell tumors. This report presents cytogenetic data on three cases of malignant ovarian germ cell tumors. All were diagnosed as malignant teratoma; case 1 with yolk sac elements; case 2 with elements of endodermal sinus tumor, embryonal carcinoma, and choriocarcinoma; and case 3 with yolk sac elements and embryonal carcinoma. Metaphase cells from each tumor, and normal tissue from the host, were karyotyped and scored for centromeric heteromorphisms in an attempt to determine the mechanism of origin. The karyotypes were 79,XXX,+1,+3,-6,+8,+12,+14,-15,+17, +20,+21,+22;49,XX,+8,+12,+22; and 48,XX,+3,+14, respectively. The analysis of centromeric heteromorphisms and DNA fingerprints of host and teratoma using the M13 probe revealed that one case originated from a germ cell before the first meiotic division. Normal host tissue was not available in case 2, but several centromeric markers were heterozygous in the tumor, indicating either meiosis I error or complete failure of germ cell meiosis. In the third case the centromeric heteromorphisms that were heterozygous in the host appeared to be homozygous for certain chromosomes and heterozygous for others in the tumor. These results suggest that germ cell teratomas could arise by the fusion of two ova.


Cell-cycle progression rates and sister chromatid exchange frequencies in the bone marrow of patients with myelodysplastic syndrome and acute myeloid leukemia. The proliferation characteristics of leukemic cells may be a determining factor in disease course and response to therapy. The present study compares the rate of cell-cycle progression in the bone marrow of 16 hematologically normal subjects, 19 patients with acute myeloid leukemia (AML), and 23 patients with myelodysplastic syndrome (MDS). The frequency of sister chromatid exchanges (SCE) in bone marrow cells is also compared. MDS and AML patients showed a reduction in the rate of cell-cycle progression compared with normal subjects. Patients with 'high risk' MDS (RAEB/RAEB-t) did not differ significantly from patients with AML but had a significantly slower rate of cell-cycle progression than patients with 'low-risk' MDS (PASA/RA). There was no correlation between the rate of cell-cycle progression and clonal karyotype status or the percentage of blast cells in either MDS or AML. There were no significant differences in SCE frequency between normal subjects and MDS or AML patients.


Trisomy of chromosome 8 in myelodysplastic syndrome. Significance of the fluctuating trisomy 8 population. Chromosome analyses were performed in five patients with myelodysplastic syndrome (MDS) who showed trisomy of chromosome 8 during the course of their disease. Four of these patients showed trisomy 8 at the diagnosis of MDS, and the remaining one had trisomy 8 when the leukemia phase developed. The proportion of bone marrow (BM) cells with trisomy 8 in the four patients who showed trisomy 8 at MDS diagnosis fluctuated, and this fluctuation was not related to the percentage of blasts in the BM or to progression of the disease. However, in two patients, metaphase cells with trisomy 8 disappeared when their anemic state improved, although leuko-thrombocytopenia was still present, suggesting that the decrease in the number of BM cells with trisomy 8 reflects hematologic features in some MDS patients. These findings indicate that trisomy 8 in our MDS patients was possibly not the primary event in the genesis of the disease, and that there may have been competition between a normal karyotype clone and a trisomy-8-positive clone. Our results further suggest that the presence of a clone with trisomy 8 is not always a sign of disease progression or of poor prognosis in MDS patients.


Clinical significance of the del(20q) chromosome in hematologic disorders. Patients with hematologic neoplasias often have chromosomal aberrations in the cells of their bone marrow or unstimulated blood. One recurrent abnormality is a deletion of the long arm of chromosome 20, primarily described in polycythemia vera, but later seen in a range of hematologic disorders. We have studied 32 patients with del(20q) as the sole chromosomal aberration, investigating significance of this aberration for the clinical diagnoses, hematologic parameters, and prognoses within this patient group. According to our results, del(20q) is primarily associated with myeloid disorders, but it is not specific for any certain disease, nor does the proportion of cells with del(20q) correlate with prognosis.


Specific chromosomal aberrations correlated to transformation in Chinese hamster cells. Cytogenetic changes were investigated during the spontaneous progression of CHEF18 Chinese hamster cells towards tumorigenicity. We further report the chromosomal characterization of a series of spontaneous anchorage-independent clones, as well as of a series of tumor-derived cell lines resulting from injection of late passage cells in nude mice. The high karyotypic homogeneity (presence of four marker chromosomes strictly associated in all the metaphases analyzed) in all clones and tumor-derived cell lines prompted us to alter the specific pattern of chromosomal aberrations in order to identify which if any of the aberrations were more strictly related to transformation. For this purpose we treated a tumor-derived cell line with Colcemid and analyzed the reversion of anchorage-independent phenotype in the subclones showing an altered association of the four marker chromosomes. We conclude that two of four marker chromosomes contribute to anchorage independence.


Trisomy 4 in a case of acute lymphocytic leukemia (L1). Trisomy 4 has been identified previously as a chromosome abnormality associated with acute nonlymphocytic leukemia (ANLL) with myelomonocytic lineage and in myelodysplastic syndromes (MDS). We report a case of acute lymphocytic leukemia (ALL) (French-American-British, FAB L1) in a 42-year-old Japanese man, with trisomy 4 as the sole chromosomal anomaly. Immunophenotypically, the leukemic blasts demonstrated reactivity with CD2, CD5, and CD7 and indicated on early stage of T cell.


Differential expression of DNAseI-sensitive sites in metaphase chromosomes of T and B lymphocytes. Thirty-one recurrent DNAseI-sensitive sites were expressed in G-banded metaphases of cultured T and B lymphocytes. Approximately one-half of these sites were found in both T and B cells and the other half were differentially expressed in the two cell types. The DNAseI-sensitive sites showed a strong correlation with the chromosomal gene location of T-cell receptors, interleukins produced by lymphocytes, and mapped surface antigens involved in the activation/proliferation of lymphocytes. The findings suggest that the chromatin of these very active genes remain accessible to DNAseI during cell division, and may help determine their precise chromosomal location.


Trisomy 8 and 11 in refractory anemia with excess blasts in transformation (RAEB-T). There are no specific chromosomal abnormalities associated with refractory anemia with excess blasts in transformation [RAEB-T]. An 80-year-old white male with RAEB-T was found to have trisomies of chromosomes 8 and 11, i.e., 48,XY,+8,+11. To our knowledge, this chromosomal abnormality in RAEB-T has not been previously reported.


[An echographic study of left ventricular function in acute myocardial infarct undergoing thrombolysis]. To evaluate the changes of left ventricular diastolic and systolic function and the timing of these changes in the early stages of acute myocardial infarction, serial echocardiograms were performed in 10 male patients (mean age of 56 years) with acute myocardial infarction, undergoing reperfusion by thrombolysis (recombinant tissue plasminogen activator). Echocardiograms were performed before reperfusion and 3, 6, 12, 24, 48, 72 hours, 7 and 14 days after thrombolysis. Significant differences of heart rate, systolic and diastolic blood pressure, left ventricular end diastolic volume, end-systolic volume and ejection fraction were not found. The mean regional wall motion index improved from 1.02 +/- 0.50 to 0.89 +/- 0.51 (p less than 0.05) at 48 hours; to 0.79 +/- 0.46 (p less than 0.01) at 72 hours; to 0.69 +/- 0.43 (p less than 0.001) at 7 days and to 0.61 +/- 0.40 at 14 days (p less than 0.001). The deceleration time decreased from 223 +/- 33 to 169 +/- 30 ms (p less than 0.001) 24 hours after reperfusion without further improvement. E peak velocity and E/A ratio significantly increased at 72 hours, while A peak velocity was not statistically different. A slow and progressive recovery of left ventricular function occurred after thrombolysis in acute myocardial infarction. Left ventricular diastole improves earlier while regional systolic function improves slowly till the hospital discharge.


[Transcatheter radiofrequency modulation and ablation of the atrioventricular junction in supraventricular arrhythmias refractory to medical therapy]. In patients with supraventricular tachyarrhythmias refractory to medical therapy, transcatheter ablation (TA) is necessary. From January 1990, in 27 patients with nodal tachycardia and 6 with atrial fibrillation or flutter, referred to our institution for electrophysiologic evaluation, TA by radiofrequency (RF) was performed, respectively for atrioventricular (AV) junction modulation and total AV junction ablation. In all these cases, a total refractoriness to several antiarrhythmic drugs alone or in combination had been observed. The RF current, generated by the Osypka HAT 100 device, was administered through a tripolar USCI 7 F catheter. The ideal site for energy delivery was defined on the basis of a mapping, performed in the AV junction area to find out the most premature retrograde atrial activation. Local atrial activation time was evaluated during nodal tachycardia by delivering a premature ventricular extrastimulus to discover the atrial deflection from the ventricular one. In the selected area, 5 applications (range 1-12) of 20-25 W power RF energy for 5-30 s were delivered on average. A complete prevention of nodal tachycardia was achieved in 26/27 patients (96.2%). Only in 2 patients (7.4%) a total AV block was induced. The pre- and post-procedure values are as follows: AH = pre 71 +/- 18, post 113.2 +/- 53; HV = pre 46.4 +/- 8, post 48 +/- 7; anterograde Wenckebach point = pre 352 +/- 56, post 389 +/- 91; retrograde Wenckebach point = pre 338 +/- 75, post 419 +/- 61. In 13/27 cases the AH interval was normal after RF application. The retrograde conduction was worsened in all patients and totally abolished in 12/27.(ABSTRACT TRUNCATED AT 250 WORDS)


[Microcirculatory changes in mitral prolapse as an expression of a systemic change in the connective tissue]. Many authors hypothesize that mitral valve prolapse (MVP) can be, in most cases, only a clinical sign of a primitive and systemic disorder of the connective tissue, like in Marfan Syndrome (MS). In our previous works we supported the presence of morphological and functional alterations of the microcirculation in patients affected by MS. In order to characterize a possible common denominator between these pathologies we have studied the cutaneous microcirculation in a group of patients affected by MVP, divided into 2 groups: anatomic MVP (MVP) and MVP syndrome (MVPS). The morphologic parameters have been investigated by nailfold capillaroscopy while digital laser-Doppler was used to study skin flowmetry. The results have been compared with a control group. Capillaroscopic remarkers showed an architecturally disorganized microvasculature with aspects related to a reduced compactness of the microvasculature unit with a significatively higher score compared with controls (7.3 +/- 2.9 vs 3.6 +/- 1 p less than 0.0005). Laser-Doppler flowmetry showed a significatively reduced rest flow; ischemic test showed: spike time 48.9 +/- 36.9 vs 15.3 +/- 7.7 s (p less than 0.0005), hyperemic acme 6.6 +/- 2.7 vs 12.5 +/- 8.4 UP (p less than 0.002); % increase 32.1 +/- 20.2 vs 51.5 +/- 15.4 (p less than 0.002). Thermic test showed a significatively higher thermic acme 8.7 +/- 4.2 vs 12.6 +/- 9.11 UP (p less than 0.05). These results appeared to be correlated with stage pathology as it was observed a severe microvasculature disorders in MVPS. Therefore we suppose that a phenotypic continuum may exist between MS and MVP.


Transcatheter ablation of the accessory pathway in 2 patients with life-threatening tachyarrhythmias. Successful transcatheter ablation of an accessory pathway in 2 patients with life-threatening tachyarrhythmias is reported. In both cases, electrophysiological evaluation documented the posterior septal location of the anomalous atrioventricular connection. Radiofrequency current energy was delivered just below the coronary sinus orifice, and resulted in disappearance of preexcitation. During the follow-up, both patients remained free from tachyarrhythmias on no medication, and serial electrocardiographic recordings confirmed the persistent absence of preexcitation. It is concluded that ablation of accessory pathways can be accomplished easily and without risk by means of the radiofrequency catheter technique. This therapeutic modality requires a short hospitalization and can be recommended as the first option in patients with the Wolff-Parkinson-White syndrome.


[Accidental ventricular fibrillation during transesophageal atrial overdrive]. Transesophageal atrial overdrive stimulation is a widely used technique for the interruption of atrial flutter and supraventricular tachyarrhythmias. We describe a case of 60 year old man with a previous myocardial infarction, suffering from angina during effort after aortocoronary bypass who presented several episodes of atrial flutter treated with success by transesophageal atrial overdrive stimulation using swallowing electrodes. During the treatment of the last episode of atrial flutter, after a 5 s burst at 300 b/min ventricular fibrillation occurred and was promptly interrupted by DC shock. This is the first case in our experience and probably the first report of ventricular fibrillation induced by swallowing electrodes. Possible mechanisms as pharmacological interactions, accidental ventricular stimulation, etc, are discussed. In conclusion, even though the risk of dangerous arrhythmias is very low, transesophageal atrial overdrive stimulation should be performed by experts in an equipped room.


Effects of chewing gums sweetened with sorbitol or a sorbitol/xylitol mixture on the remineralisation of human enamel lesions in situ. Intra-oral remineralisation of experimental caries-like lesions in human enamel, as determined by polarised light microscopy and quantitative microradiography, was promoted to a similar extent (% fall in delta Z, 18.6 and 19.0) by chewing a sorbitol or sorbitol/xylitol (3:1)-sweetened gum for 20 min after each of three meals and two sugary snacks daily. The results suggest that reported differences in the properties of the two sweeteners do not affect their ability to enhance remineralisation due to salivary stimulation.


Purification, characterization and inhibition by fluoride of enolase from Streptococcus mutans DSM 320523. Enolase from Streptococcus mutans has been purified to homogeneity by a three-step procedure. As shown by analytical ultracentrifugation and polyacrylamide gel electrophoresis under denaturing conditions, the purified enzyme is an octamer with molecular weight Mr = 360 kDa, composed of eight identical subunits with Mr = 45 kDa. The kinetic parameters of S. mutans enolase in the presence of 1 mM Mg2+ are Aspec = 130 IU x mg-1 and KM = 0.44 mM as determined by steady-state experiments in the D-glycerate 2-phosphate to enolpyruvate phosphate reaction. Enzymatic activity is inhibited noncompetitively by fluoride in the range between 0 and 10 mM NaF yielding Ki = Kii = 1.39 mM, but inhibition characteristics become competitive when tested above 10 mM. In the presence of only small amounts of phosphate (0.5 mM) the inhibitory effect of fluoride is enhanced dramatically yielding Ki = 0.26 mM. Inhibition by NaPO3F is competitive with Ki = 0.9 mM, indicating that free fluoride ions in combination with phosphate are more effective in inhibiting S. mutans enolase. It can be concluded that inhibition of enolase by fluoride in combination with phosphate can influence glycolysis in S. mutans and so reduce acid production or even growth rate, thereby leading to potential anticariogenic effects.


Effects of tung oil on salivary viscosity and extent and incidence of dental caries in rats. Increased salivary viscosity may be associated with an increase in dental caries. In order to examine this relationship, the caries level in rats was monitored following gastric intubation with tung oil which has been shown to significantly increase salivary viscosity. Tung oil intubation over an 8-week period significantly increased the salivary viscosity in rats as compared with deoinized water and corn oil intubation. The total number of carious lesions was significantly increased (p less than 0.05) in the tung oil intubated rats as compared with the two other groups. This increase in carious lesions was primarily associated with the smooth surfaces of the teeth. There was also a significant increase (p less than 0.05) in the extent of enamel and dentin involvement of the tung oil intubated rats as compared with the other two groups. Histologic examination of the submandibular glands revealed an increase in the amount of glycoprotein material in the convoluted granular tubules of the tung oil intubated rats as compared with the deionized water and corn oil intubated animals. Collectively, these results suggest that tung oil intubation is correlated with both increased salivary viscosity and increased smooth-surface dental caries, suggesting that the viscosity may be related to dental caries progression.


Effects of hyposalivation on the oral microflora of rats fed sucrose or wheat flour diets. The effects of hyposalivation on the induction of dental caries and on the composition of the oral microflora were examined in specific pathogen-free Sprague-Dawley rats fed either a sucrose or a wheat flour diet with or without inoculation of Streptococcus mutans. Significant dental caries was induced in hyposalivated rats fed diet 2000 containing 56% sucrose, irrespective of infection by S. mutans. Diets containing 56% wheat flour did not induce dental caries in either hyposalivated or sham-operated rats, irrespective of infection by S. mutans. Bacteriological examinations at the end of the experiment demonstrated that the total numbers of lactobacilli and staphylococci increased in hyposalivated rats irrespective of the diet given, while the inoculated stain of S. mutans decreased significantly in hyposalivated rats. These findings suggest that some acidogenic microorganisms such as lactobacilli and staphylococci that can utilize sucrose or glucose but not wheat flour may also promote dental caries in hyposalivated rats.


An in vivo comparison of radiographic and directly assessed clinical caries status of posterior approximal surfaces in primary and permanent teeth. At general dental practices in Scotland 211 children between the ages of 5 and 15 years were examined by 1 observer. A comparison of the status of 1,468 permanent and 756 primary posterior approximal surfaces was made on the basis of their appearance on posterior bite-wing radiographs and the findings of a direct in vivo visual examination, made after temporary tooth separation had been achieved over 1 week using elastomeric separation. For permanent tooth surfaces, 0% of radiolucencies in the outer half of enamel, 10.5% in the inner half of enamel, 40.9% extending to the outer half of dentine, and 100% extending to the inner half of the dentine were found clinically to be cavitated. The analogous results for primary teeth were that 2.0, 2.9, 28.3, and 95.5%, respectively, of radiolucencies appeared to be cavitated. Although further research with larger numbers of permanent teeth is indicated, these results may contribute to a re-evaluation of the optimal threshold for restorative intervention at approximal sites. Greater numbers of approximal radiolucencies and carious lesions (p less than 0.001) were found in those surfaces which initially had a normal anatomical contact when compared to those which did not.


Hexahedrally based crystals in human tooth enamel. Mg-containing calcium phosphate crystals including pseudocuboidal, rhombohedral shapes and groupings of quadrangular blades cubically arranged were found in human tooth enamel by scanning electron microscopy and by electron probe microanalysis. In caries-free old enamel, these hexahedrally based crystals measuring 0.5-2.5 microns in length were observed in some crevices of tufts and lamellae. The crystals were rarely seen in the inner crevices of caries-free exfoliated deciduous enamel and none could be seen in sound young enamel. In brown-coloured old enamel possessing arrested caries with lamellae, some of the lamellae contained crystals measuring 0.1-1.5 mu in length adjacent to half-dissolved prisms. These crystals, identified as Mg-containing whitlockite, will grow during a long period after eruption of the tooth or during the enamel caries process.


The influence of various amphiphilic phosphates on in vitro caries lesion formation in human dental enamel. Some newly designed surface-active phosphates were investigated with respect to their capacity to inhibit caries lesion formation in vitro. On the labial or buccal surfaces of sound human third molars, windows were prepared for investigation. One half of each window was treated with the test compound at pH values of 7.5, 5.5, or 3.5. The other half served as a control. Both halves were demineralized and the generated caries lesions in both parts were compared by means of quantitative microradiography. Mono-, bis- and trisphosphates differed only marginally in their effect on the demineralization. The compounds diminished the demineralization down to 30% of that of untreated enamel. Per molecule at least one long alkyl chain (more than 12 C atoms) was required for achieving decreased demineralization, indicating the importance of a low surface tension. The results suggest that some of the tested compounds have promising properties for their use as anticaries agents, especially when applied in combination with fluoride.


An in vitro assessment of the extent of caries under small occlusal cavities. Many clinicians take for granted that occlusal caries which is just visible as a cavity is extended (deep) into the dentine. This study was aimed at quantifying this opinion. The study was carried out with 60 molars containing small but visible occlusal cavities. After taking bite-wing radiographs the crowns were separated from the roots and embedded. 700-microns sections were cut and glued on plastic sheets. X-ray pictures were taken of the sections which were scored by independent examiners. The bite-wings provided inaccurate estimates of the extent of caries. Radiographs of the sections revealed that about 25% of the molars had caries which reached just to the dentino-enamel junction, while the remaining 75% showed caries extending far into the dentine.


Determination of volumes of fluid in the mouth by fluoride dilution. A dilution technique, with fluoride as a marker, has been developed to measure the volume of saliva and other fluids in the mouth. Immediately after swallowing, a small amount of fluoride solution is placed in the mouth, mixed with the oral fluids, and expelled from the mouth. The fluoride concentration of the expelled oral fluid is measured and the volume of fluid in the mouth at the time of spitting calculated from the fluoride dilution. Mean values of 0.75 +/- (SD) 0.28 ml for males and 0.72 +/- (SD) 0.16 ml for females were recorded. The accuracy of the volume determination is about +/- 0.10 ml in vivo. This technique has provided a convenient and rapid means of determining saliva volumes. It could also be used to determine rates of secretion and may prove useful in the clinic for assessing a patient's salivary competence.


Limitations in the intraoral demineralization of bovine enamel. A model system was used to examine the relation between the duration of plaque pH fall and enamel demineralization following the intake of dietary carbohydrate in humans. Subjects wore palatal appliances containing blocks of bovine enamel covered with Streptococcus mutans IB 1600, and rinsed with 5 or 10% sucrose. Changes in iodide penetrability (delta Ip) of the enamel, and the pH and extracellular calcium and inorganic phosphate (Pi) concentrations of the streptococcal plaque were determined. Following rinses with 5% sucrose, delta Ip increased with time and reached a maximum (11.2 +/- 2.2 units) at 45-60 min although the S. mutans plaque remained acidic (pH = 4.8 +/- 0.6). After 10% sucrose, the maximum (14.7 +/- 3.1 units) was reached while the plaque pH was 4.0 +/- 0.3. Second rinses with sucrose increased delta Ip at most by 30%. Thus, demineralization did not persist throughout the period of low plaque pH, but occurred primarily during the early phase of plaque acidogenesis. Enamel demineralization appeared to be limited by factors other than the pH of the streptococcal plaque. Calcium concentrations in the S. mutans plaque rose to a maximum of 10.9 +/- 2.8 mEq/l at 30 min after the 5% sucrose rinses, then fell; Pi reached a stable level of 12.2 +/- 2.3 mEq/l by 60 min. Calculations showed that conditions approached saturation with respect to enamel and dicalcium phosphate dihydrate as demineralization reached a maximum. Demineralization appeared to be limited at low plaque pH, therefore, by the accumulation of high levels of mineral ions in the streptococcal plaque.(ABSTRACT TRUNCATED AT 250 WORDS)


Reliability of Doppler echocardiographic stroke volume measurement. To evaluate the accuracy and utility of the echocardiographic Doppler method of determining the stroke volume, the stroke volume was measured in 64 instances in 15 patients and compared to the simultaneous thermodilution stroke volume determinations. Stroke volume, varied by atrial pacing at various heart rates, was calculated noninvasively by the product of the cross-sectional area of the aortic orifice determined by echocardiography and the flow velocity integral measured by continuous wave Doppler. While the cardiac output was increased moderately by atrial pacing, the stroke volume was decreased in relation to the increase in the heart rate. The stroke volume calculated by the echo-Doppler method exhibited a significant linear relationship to the stroke volume determined by thermodilution (r = 0.84) and to the cardiac output (r = 0.75, p less than 0.01). Inter-observer and intra-observer variability was 7 +/- 4% and 5 +/- 4%, respectively. The noninvasive echo-Doppler method of estimating the stroke volume is concluded to be accurate, specifically, to be comparable to the values obtained by thermodilution and with a low inter- and intra-observer variability.


Alterations in nuclear envelope invaginations in axotomized fetal and early postnatal hamster facial motoneurons. In this study, changes in the amount of nuclear envelope invaginations (NEI) were morphometrically assessed after axotomy during late fetal and early postnatal developmental stages in hamster facial motoneurons. These changes were expressed as boundary density or BA (length of nuclear envelope per unit area of nucleus). Axotomy-induced changes in nuclear area and perimeter were also quantitatively determined. At 17 h after axotomy in the fetal operative series, no changes in any of the parameters were seen. At 1 day postoperative (dpo) in newborn, 2 and 4 postnatal day animals, the boundary densities of the total and invaginated portion of the nuclear envelope increased significantly. No corresponding qualitative changes were observed. At 2 dpo in 4 and 7 postnatal day animals, there were significant increases in the boundary densities of both invaginated and total nuclear envelope and a decrease in nuclear area. These changes were not seen at 2 dpo in the 9-day operative series. At 4 dpo in 7 and 9 postnatal day animals, scalloping of the normally smooth nuclear profile, as well as a flattening and elongation in nuclear shape, occurred. These qualitative changes in the 7 and 9 day operated groups were also accompanied by significant changes in all the measured parameters. The boundary density of the invaginated, non-invaginated and total nuclear envelope increased; whereas, nuclear area and perimeter decreased. These results argue against the generally held hypothesis that an increase in nuclear envelope invaginations is indicative of an allied increase in cellular metabolism.(ABSTRACT TRUNCATED AT 250 WORDS)


Expression of lectin binding in the superficial dorsal horn of the rat spinal cord during pre- and postnatal development. The plant lectin Bandeiraea simplicifolia I-B4 binds to the soma and central terminals of a subpopulation of unmyelinated primary sensory neurones in the adult rat. The binding site of this lectin is thought to be the terminal alpha-D-galactose residue of a membrane associated glycoconjugate which may be involved in the development of specific connections between small diameter primary sensory neurones and second order neurones in the superficial dorsal horn of the spinal cord. To begin to investigate this possibility we have examined the development of lectin binding in the dorsal horn of pre- and postnatal rats. Lectin binding first appeared on axon profiles in the superficial dorsal horn of the spinal cord at embryonic days 18/19. Previous studies in the rat have revealed that the central processes of small diameter primary sensory neurones enter the dorsal horn at embryonic days 18/19. Our findings suggest that the glycoconjugate to which this lectin binds, is expressed by the central processes of small diameter primary sensory neurones as they grow into the spinal cord. It is therefore possible that this glycoconjugate is involved in the development of topographically ordered neural connections within the dorsal horn of the spinal cord.


Differential distribution of two microtubule-associated proteins, MAP2 and MAP5, during chick dorsal root ganglion development in situ and in culture. Microtubule-associated proteins (MAPs) are essential components necessary for the early growth process of axons and dendrites, and for the structural organization within cells. Both MAP2 and MAP5 are involved in these events, MAP2 occupying a role predominantly in dendrites, and MAP5 being involved in both axonal and dendritic growth. In the chick dorsal root ganglia, pseudo-unipolar sensory neurons have a T-shaped axon and are devoid of any dendrites. Therefore, they offer an ideal model to study the differential expression of MAPs during DRG development, specifically during axonal growth. In this study we have analyzed the expression and localization of MAP2 and MAP5 isoforms during chick dorsal root ganglia development in vivo, and in cell culture. In DRG, both MAPs appeared as early as E5. MAP2 consists of the 3 isoforms MAP2a, b and c. On blots, no MAP2a could be found at any stage. MAP2b increased between E6 and E10 and thereafter diminished slowly in concentration, while MAP2c was found between stages E6 and E10 in DRG. By immunocytochemistry, MAP2 isoforms were mainly located in the neuronal perikarya and in the proximal portion of axons, but could not be localized to distal axonal segments, nor in sciatic nerve at any developmental stage. On blots, MAP5 was present in two isoforms, MAP5a and MAP5b. The concentration of MAP5a was highest at E6 and then decreased to a low level at E18. In contrast, MAP5b increased between E6 and E10, and rapidly decreased after E14. Only MAP5a was present in sciatic nerve up to E14. Immunocytochemistry revealed that MAP5 was localized mainly in axons, although neuronal perikarya exhibited a faint immunostaining. Strong staining of axons was observed between E10 and E14, at a time coincidental to a period of intense axonal outgrowth. After E14 immunolabeling of MAP5 decreased abruptly. In DRG culture, MAP2 was found exclusively in the neuronal perikarya and the most proximal neurite segment. In contrast, MAP5 was detected in the neuronal cell bodies and all along their neurites. In conclusion, MAP2 seems involved in the early establishment of the cytoarchitecture of cell bodies and the proximal axon segment of somatosensory neurons, while MAP5 is clearly related to axonal growth.


Effects of prenatal morphine on adult sexual behavior and brain catecholamines in rats. Female rats exposed to morphine in utero (5-10 mg/kg twice a day on days 11-18 of gestation) were significantly inhibited in their sexual behavior when compared to saline-exposed controls. In contrast, males exposed prenatally to morphine had shorter post-ejaculatory intromission latencies and, after the first test, exhibited increased mounting and intromitting activity relative to controls. Examination of the brain catecholamine content revealed that morphine in utero may permanently alter adult hypothalamic norepinephrine levels in male and female rats. The morphine-induced alterations in hypothalamic norepinephrine levels were sexually dimorphic. In the hypothalamus of male rats, norepinephrine content was increased 95%, whereas in the hypothalamus of female rats it was decreased 57% relative to controls. These results suggest that prenatal morphine exposure, which differentially affects adult male and female sexual behavior, also alters hypothalamic norepinephrine content in a sexually dimorphic fashion.


Postnatal administration of dihydrotestosterone to the male rat abolishes sexual dimorphism in the accessory olfactory bulb: a volumetric study. The regulatory action of the non-aromatizable androgen dihydrotestosterone (DHT) on sexual differentiation of the volume of the rat accessory olfactory bulb (AOB) was studied. Postnatal treatment with DHT (180 micrograms/day) carried out daily between days 6 and 20 produced a drastic reduction in overall AOB size and that of its constituent neural layers in genetic males with respect to intact and control males. The volumetric measures found in DHT-treated males did not differ from those shown by the intact females. These results, which indicate a demasculinization and a feminization of the AOB volume in gonadally intact male rats induced by DHT, are discussed in relation to the presumably regulatory role of DHT on neuron populations during the sexual organizational process of the brain.


Developmental changes in brain kynurenic acid concentrations. The cerebral distribution and regulation of excitatory amino acid levels may play a crucial role in neuronal development. In the present study we examined concentrations of the endogenous excitatory amino acid antagonist kynurenic acid and related substances during development in fetal and neonatal rat brain and fetal non-human primate cerebral cortex. Kynurenic acid concentrations in rat fetal whole brain were significantly increased 4-5 fold prenatally, then declined rapidly at 1 day after birth, and reached adult concentrations at 7 days after birth. L-Kynurenine concentrations were also markedly increased prior to birth and then declined to adult concentrations at 1 day after birth. L-Tryptophan was increased 3 fold before birth, and decreased to adult concentrations 1 day after birth. In contrast concentrations of dopamine, norepinephrine, 3,4-dihydroxyphenylacetic acid and homovanillic acid increased 1 day prior to birth and continued to increase following birth. Fetal baboon cerebral cortex showed significant increases in kynurenic acid concentrations both pre-term and near-term as compared with adult concentrations. These results show that marked changes in kynurenic acid concentrations occur prior to and following birth. It is possible that high levels of kynurenic acid prior to birth inhibit neurite branching and development of excitatory synapses, which then develop rapidly in parallel with the decrease in kynurenic acid levels.


Kindling in developing animals: interactions between ipsilateral foci. In adult rats, concurrent kindling of two limbic sites, alternating stimulation to each site, often results in the retarding of kindling at one or both sites. This inhibitory interaction between two limbic kindling foci is termed kindling antagonism and occurs irrespective of whether the sites are contralateral or ipsilateral. We have previously shown that kindling antagonism does not occur when 16- to 17-day-old rat pups are concurrently kindled in the hippocampus and contralateral amygdala or between the two amygdalae. In this study, adult and 16- to 17-day-old rats were concurrently kindled in the hippocampus and ipsilateral amygdala to determine if the local intrahemispheric mechanisms suppressing multiple kindled foci are age-dependent. Kindling antagonism occurred in 7 out of 10 adult rats. In contrast, in rat pups, kindling development was not suppressed. Concurrent kindling of the two limbic sites enhanced the development of severe seizures. Two 16- to 17-day-old rats receiving alternating stimulations exhibited spontaneous seizures. The age-specific failure of both inter- and intrahemispheric mechanisms to suppress the development of multiple kindling foci may explain the high incidence of multifocal seizures in the immature CNS.


Laminin--developmental expression and role in axonal outgrowth in the peripheral nervous system of the chick. The possible role of laminin on axon outgrowth and guidance in vivo was examined by: (1) determining its developmental expression, and relationship to outgrowth of sensory, motor and sympathetic axons in the chick embryo; and (2) evaluating the changes in the pattern of sympathetic preganglionic projections subsequent to injections of laminin, antilaminin and other laminin function blockers (JG22, INO) into their pathways during axon outgrowth. Double immunofluorescent staining for laminin and neurofilaments in peripheral nerves prior to and during initial outgrowth showed no obvious relationship between laminin and potential nerve pathways. Even though weak laminin immunostaining is apparent throughout the mesenchyme through which axons grow, the most prominent laminin immunostaining is on basement membranes of the neural tube, notochord and dermamyotome. However, as peripheral nerves mature, laminin becomes localized to nerve fascicles throughout the peripheral nervous system, beginning with the dorsal and ventral roots, and progressing later to more distal spinal nerves. Microinjections of antilaminin, JG22 (a monoclonal antibody against laminin/fibronectin receptors) and INO (a monoclonal antibody against a laminin-heparan sulfate proteoglycan complex) into the pathway of sympathetic preganglionic axons prior to and during outgrowth had no effect on the spatio-temporal patterns of sympathetic preganglionic projections. An alternate laminin-rich pathway produced by injecting laminin into the region of the sympathetic trunk immediately adjacent but caudal to the T1 spinal level also did not alter the projection of T1 preganglionic axons. These results suggest that laminin may not be crucial to the initial of peripheral axons. The localization of laminin in nerve fascicles in later stages of development suggests instead that laminin may be important in the maintenance of these structures.


Behavioral effects of continuous hippocampal stimulation in the developing rat. There is controversy as to whether prolonged seizures are more detrimental to the immature than the mature brain. To evaluate this question continuous hippocampal stimulation was used to induce prolonged limbic seizures in 20-, 30- and 60-day-old rats. The long-term effects on learning and activity level were then studied at age 80 days using the Morris water maze, a test of spatial learning and memory, and the open field test, a test of an animal's reaction to a novel environment. Limbic status epilepticus in 60-day-old but not 20- and 30-day-old rats caused long-term impairment of learning in the Morris water maze. No differences were noted between the control and the experimental animals in the open field test. These results suggest that the age of seizure onset is an important determinant of long-term cognitive sequelae.


Platelet-derived growth factor B-chain-like immunoreactivity in the developing and adult rat brain. Platelet-derived growth factors (PDGFs) are growth-regulatory molecules that stimulate chemotaxis, proliferation and increased metabolism, primarily of connective tissue cells. In our previous paper, we have demonstrated the ubiquitous localization of PDGF B-chain-containing proteins in neurons and expression of transcripts for PDGF A-chain, B-chain and the two forms of the PDGF receptor in the brains of non-human primates. In the present study, the cellular localization of PDGF B-chain in developing and adult rat brains was analyzed using immunocytochemistry with a PDGF B-chain-specific monoclonal antibody. Intense PDGF B-chain immunoreactivity (PDGFB-I) was distributed around the continuously regenerating primary olfactory neurons at all stages of development from embryo to adult. The major part of PDGFB-I associated with neurons appeared some time after birth and increased with age. PDGFB-I appeared in several nerve fiber systems during earlier stages of development and gradually decreased with age. In conjunction with other data showing the existence of functional PDGF receptor beta-subunits in the neurons, these data suggest a possible role for PDGF B-chain as a neurotrophic or neuroregulatory factor in both developing and mature brains.


The mas proto-oncogene is developmentally regulated in the rat central nervous system. The mas proto-oncogene encodes a protein with a predicted structure similar to members of the family of seven transmembrane domain spanning receptors. These receptors are thought to transduce extracellular signals to G-proteins. Angiotensin II and III have been reported to be the functional ligands for the mas oncogene-encoded receptor (Jackson et al., 1988). We show here using in situ hybridization histochemistry and RNase protection assays that mas mRNA is expressed in a subpopulation of neurons in both the adult and developing rat CNS. In the adult CNS, mas mRNA is most abundant in hippocampal pyramidal neurons and dentate granule cells; mas transcripts are also present at low levels in the cortex and thalamus. mas is first expressed in the developing rat CNS at postnatal day 1 (P1). Even at this early stage in CNS development the pattern of mas expression is similar to that seen in the adult. Although at P1 most neurons of the dentate gyrus are not yet generated and cells of the hippocampal CA fields are undergoing migration and synaptogenesis (Bayer 1980; Altman and Bayer, 1990a, 1990b, 1990c), mas is specifically expressed in these cell populations. This extremely restricted pattern of expression suggests that mas may function in determining the morphology and connections of specific cell types in the hippocampus. This function may in part be carried out by the ability of mas to link external cues to intracellular processes.


Transient c-fos expression accompanies naturally occurring cell death in the developing interhemispheric cortex of the rat. We have searched for the possible correlation of naturally occurring cell death with spontaneously enhanced c-fos expression in the developing cerebral cortex of normal Wistar albino rats. During the late prenatal and early postnatal period, cells with irregular contours and intracytoplasmic electron-dense granules (granule-containing cells) were apparent in the interhemispheric cortex, including the anterior cingulate and the retrosplenial cortices. These cells were loosely packed within the cortical layers derived from the cortical plate. Having excluded the possibility that these cells could be phagocytes by immunocytochemical experiments, we propose that they are cells in different phases of a process of autophagic degeneration and death. Images of extreme nuclear pyknosis were also apparent in identical locations. Cells showing immunoreactivity for c-Fos protein appeared in the same cortical areas. The immunoreactive cells were very abundant in the retrosplenial cortex, but were also present in the anterior cingulate cortex. These cells showed markedly irregular contours and large, densely immunoreactive intracytoplasmic inclusions; these images were similar to those of granule-containing cells revealed by conventional stains. The immunoreactivity for c-Fos protein was ephemeral, occurring exclusively during embryonic days 20 and 21, but granule-containing cells were observed for a longer period. The present results provide evidence, albeit indirect, that c-fos expression may occur in certain neural cells at the onset of a process of death by autophagia, and suggest a possible involvement of the proto-oncogene c-fos in certain forms of naturally occurring neuronal death.


Neurogenesis of the amygdaloid nuclear complex in the rhesus monkey. The time course of neurogenesis for neurons which comprise the amygdaloid complex in Rhesus monkeys was determined using tritiated thymidine autoradiography. Fourteen pregnant monkeys received injections of tritiated thymidine between embryonic days 27 (E27) and 56 of their 165 day gestation and offspring were sacrificed during the early postnatal period. The first neurons destined for the amygdaloid complex were generated at E33 making them among the earliest postmitotic neurons in the telencephalon. Neurogenesis peaked within all nuclei of the amygdaloid complex between E38 and E48 and had ceased between E50 and E56. While amygdaloid neurogenesis in postnatally sacrificed monkeys displayed a dorsal-to-ventral gradient of radiolabeled neurons, the considerable rotation of the temporal lobe during the latter stages of primate development indicates that neurogenesis in the embryo, during the first third of gestation, actually occurs across a medial-to-lateral gradient. This medial-to-lateral gradient occurs as a smooth wave across the amygdaloid nuclei and does not respect neuroanatomical subdivisions or patterns of connectivity of the amygdaloid nuclei in the Rhesus monkey.


Hydra head activator peptide has trophic activity for eukaryotic neurons. The synthetic undecameric peptide, pGlu-Pro-Pro-Gly-Gly-Ser-Lys-Val-Ile-Leu-Phe, known as the hydra head activator peptide, present in high concentrations in mammalian hypothalamus and intestine, was tested for neurotrophic activity in a survival assay using cultured chick embryonic sympathetic and dorsal root ganglion cells, and for morphological differentiation activity on neuroblastoma cells. Hydra head activator peptide supported neuron survival. The optimal active concentration, 1 pM, was very similar to the concentration that causes bud and head formation in hydra. Maximal neuron survival obtained with hydra head activator peptide was close to that obtained with nerve growth factor: both substances enhanced survival up to 3 times that of control cultures. Bradykinin, which has some amino acid sequence homology with hydra head activator, was inactive as a neurotrophic factor. Hydra head activator induced rapid morphological differentiation of the mouse neuroblastoma cell line Neuro-2A. Neuro-2A responded to the peptide by process extension, 4 h after its addition to the culture medium. Neurotrophic factors isolated to date have been characterized by their ability to maintain cell viability and enhance neurite outgrowth. Hydra head activator peptide met these two criteria when tested in 3 different neuron culture systems. Our results suggest that the head activator peptide may act as a neurotrophic factor for neurons in other species, including mammals.


Generation of analytic plasma lipoprotein profiles using two prepacked superose 6B columns. A simple, low-priced chromatographic system to generate plasma lipoprotein profiles from total human plasma was tested with plasma from normolipidemic subjects and patients with heterozygous familial hypercholesterolemia, hyper-alpha-lipoproteinemia, lipoprotein lipase deficiency, familial dysbetalipoproteinemia and familial lecithin-cholesterol-acyl-transferase deficiency. The system appears to be a good alternative to more expensive high-pressure liquid chromatography systems, notably in lipoprotein laboratories already provided with equipment for column chromatography. If a microplate photometer and a computer is available in the laboratory, the measurement of various lipids in 70-80 eluant fractions from the columns can be simplified.


Homocarnosinosis patients and great apes have a serum protein that cross-reacts with human serum carnosinase. A specific polyclonal antiserum to human serum carnosinase was raised in rabbits and was used to prepare an agarose-protein A-antibody matrix. An antigen capture procedure showed that sera from homocarnosinosis patients, which lack carnosinase activity, contain an immunoreactive protein (M(r) 75,000) indistinguishable from the carnosinase band from normal serum. Other higher primates have active serum carnosinase and a similar immunoreactive M(r) 75,000 protein. The immunoaffinity matrix was used in a facile procedure to isolate pure carnosinase from human plasma with a yield of 69%. The antiserum inhibited human serum carnosinase strongly, but the maximum inhibition attained averaged only 71%. The antiserum inhibited human and chimpanzee serum carnosinases more effectively than gorilla or other higher primate serum carnosinases.


High-performance liquid chromatographic determination of free polyamines in human seminal plasma. Putrescine, spermidine and spermine were determined quantitatively in 192 ultrafiltered samples of human seminal plasma with a precision of +/- 1.9% by pre-column derivatization with benzoyl chloride and reversed-phase chromatography. The concentrations of free putrescine, spermidine and spermine ranged from 0 to 1.96 mmol/l (mean = 0.10), 0.017-0.96 mmol/l (mean = 0.16) and 0.13 to 20.80 mmol/l (mean = 2.43), respectively. A significant correlation between the amounts of spermidine and spermine was found (r2 = 0.806, P less than 0.0005). Otherwise, no significant correlations between free-polyamine levels and routine spermiogram parameters such as volume, sperm count, motility, vitality and morphology were obtained.


Mechanized assay of serum cholinesterase by specific colorimetric detection of released acid. An automated assay method has been developed for the measurement of serum cholinesterase activity. The samples were prepared by an automated liquid handling unit and incubated for 9.7 min at 30 degrees C, followed by automatic injection into a colorimetric flow injection determination system for acetic acid liberated from acetylcholine by cholinesterase catalytic activity. The coloration reaction employed is based upon the formation of 2-nitrophenylhydrazide utilizing a water-soluble carbodiimide and has a high selectivity for carboxylic acids. The coefficients of variation of the proposed method were 2.4% for within-run analysis (n = 14) and 2.6% for between-run analysis (n = 6). Sera of 55 hospitalized patients were analyzed and the values obtained correlated well with an automated differential pH method (gamma = 0.989).


Discriminant analysis of urinary calculi by near-infrared reflectance spectroscopy. Near-infrared reflectance analysis has been used to determine the qualitative and semi-quantitative composition of urinary calculi. This simple method requires calibration of the most common urinary calculi. Analysis time is short (less than 1 min) and only very small amounts of calculus in powder form (less than 100 micrograms) are required without the use of any reagent. Moreover, when compared to infrared spectroscopy, this method provides sufficient accuracy to identify mixed calculi containing two or three components, and permits semi-quantitative determinations. The speed and simplicity of this technique makes it a powerful method for the routine analysis of urinary calculi in clinical laboratories.


Tubular secretion of Tamm-Horsfall protein in type 1 (insulin-dependent) diabetes mellitus using a simplified enzyme linked immunoassay. The relationship between glomerular and tubular dysfunction and metabolic control in type 1 diabetes was studied. To that end the urinary excretion rates of albumin and Tamm-Horsfall protein as well as HbA1c levels were measured in 58 patients with different degrees of diabetic nephropathy and in 76 apparently healthy subjects matched for sex and age. The urinary Tamm-Horsfall protein levels were measured by a simplified enzyme linked immunoassay. The intra- and interassay variations were 8.9% and 13.6%, respectively. The intraindividual variation was 41% and the sensitivity of the assay was 4 micrograms/l. The Tamm-Horsfall protein excretion rate was 42.1 x/2.0 micrograms/min (geometric mean x/tolerance factor) in the diabetic patients compared to 34 x/1.9 micrograms/min in the control subjects (NS). The diabetic patients had higher albumin excretion rate (38.5 x/7.3 micrograms/min) than the control subjects (4.7 x/2.3 micrograms/min; P less than 0.001). By using multivariate analysis of variance, HbA1c level was found to be the only independent variable associated with Tamm-Horsfall protein excretion rate in diabetic patients (r = -0.28; P = 0.04), while no relationship was found between Tamm-Horsfall protein excretion rate and age, age at onset and duration of diabetes, gender, serum creatinine, diuresis, urinary albumin excretion rate, systolic and diastolic blood pressure levels and antihypertensive treatment. The urinary albumin excretion rate was associated with diastolic blood pressure (r = 0.34; P = 0.02) but not with HbA1c levels when testing the above variables by multivariate analysis of variance. In conclusion, these results may indicate a lack of relationship between glomerular and tubular dysfunction. The former was influenced only by diastolic blood pressure levels and the latter only by the degree of metabolic control. However, the correlations were weak and do not provide any insight into what is actually responsible for glomerular and tubular dysfunction.


Influences of diet and surgical trauma on serum alkaline DNase activity levels. Changes in serum alkaline DNase activities might predict the therapeutic response in various malignant diseases. A decrease in serum alkaline DNase activity within days from the onset of therapy has been related to tumour necrosis and may be a possible sign of clinical response to effective treatment. To study if changes in serum alkaline DNase activity could be induced by non-tumour related tissue destruction, sera were collected on several occasions perioperatively in 18 patients undergoing surgery for benign gynaecological disease. Thirty apparently healthy women served as the control group. A significant decrease (P less than 0.001) in serum alkaline DNase activity was observed after an overnight fast in both groups of women. In contrast to the control women, the operated patients showed a significant decrease (P less than 0.001) in serum alkaline DNase activity throughout the operative period and 1 week postoperatively. We conclude that serum alkaline DNase activity is influenced by dietary factors as well as surgical trauma. These factors may limit the clinical usefulness of SADA in patients with cancer.


Limitations of the triolein breath test. Patients being investigated for intestinal absorptive capacity were classified as normals or malabsorbers on the basis of three fat absorption tests. Malabsorbers were further classified as mild, moderate, severe or gross according to severity of malabsorption. Using this classification system the triolein breath test was evaluated in 53 patients. Seventeen patients were excluded because their graph of percentage breath [14C]carbon dioxide versus time was exponential indicating that the peak [14C]-carbon dioxide may be occurring later than the six hour duration of the test. The sensitivity and specificity of the triolein breath test were found to be 100% and 96%, respectively and moderate correlations with the individual fat absorption tests were found. However, the breath test was limited in its capacity to predict the severity of malabsorption. Carbon dioxide output was also measured in order to determine the applicability of using an assumed value. The respiratory quotient and variability of results were high in nineteen patients indicating possible hyperventilation. In 32 patients with reproducible results and normal respiratory quotients the average carbon dioxide output was 8.66 mmol/kg per hour with a wide range of 5-12.4 mmol/kg per hour. Consequently the use of an assumed carbon dioxide output can introduce considerable errors in the triolein breath test. This study highlights drawbacks of the triolein breath test, particularly problems in using an assumed carbon dioxide output for its calculation, its inability to predict the severity of malabsorption and the nature of the dietary load used.


An enzyme-linked immunosorbent assay for heparin cofactor II (HCII). Application to the measurement of HCII in clinical materials. Heparin cofactor II (HCII) is a thrombin inhibitor in human plasma, the activity of which is enhanced by heparin and dermatan sulfate. To measure the plasma antigen concentration of HCII, an enzyme-linked immunosorbent assay (ELISA) has been developed, and this is based on the use of polyclonal anti-HCII IgG, both as the antigen-capturing antibody and as the labelled antibody. The intra- and inter-assay reproducibilities have been calculated to be less than 6%. HCII antigen concentrations evaluated with this ELISA technique in clinical plasma samples correlated well with those determined by electroimmunodiffusion and with HCII activities evaluated using a functional assay (r = 0.909 and r = 0.930, P less than 0.0001). Since the correlation between HCII deficiency and thrombosis is still a controversial issue, the ELISA technique described in this report could be a useful tool for the large-scale studies needed to determine the prevalence of HCII deficiency in healthy individuals and in patients with a history of thrombosis.


Selenium and glutathione peroxidase variations induced by polyunsaturated fatty acids oral supplementation in humans. Serum and erythrocyte selenium, erythrocyte and platelet glutathione-peroxidase (GSH-Px) activities, and erythrocyte reduced glutathione (GSH) content were measured in 25 healthy adult individuals before and after daily supplementation with 20 ml of fish oil for 10 weeks. Serum-Se decreased from 0.83 +/- 0.01 mumol/l to 0.75 +/- 0.02 mumol/l (mean +/- S.E.M.) (P less than 0.01); erythrocyte-Se decreased from 4.39 +/- 0.17 nmol/g hemoglobin (Hb) to 2.83 +/- 0.15 nmol/g (P less than 0.001). GSH-Px activities increased both in erythrocytes (6.93 +/- 0.24 iu/g vs 8.18 +/- 0.27 iu/g Hb, P less than 0.01) and in platelets (69.2 +/- 2.8 iu/g vs 90.9 +/- 3.6 iu/g protein, P less than 0.001). The concentration of GSH in erythrocytes fell from 9.56 +/- 0.29 mumol/g Hb to 5.90 +/- 0.30 mumol/g Hb (P less than 0.001). The effects on plasma lipids were evident only for triglycerides (before 1.96 +/- 0.16 mmol/l, after 1.75 +/- 0.14 mmol/l, P less than 0.001). We hypothesise the enrichment of erythrocyte and platelet membranes with polyunsaturated fatty acids (PUFAs), following fish oil intake, can generate increased amounts of lipid peroxides and thus allosterically activate GSH-Px: with time this is harmful for the integrity of the enzyme molecule and Se release may result. We suggest that the Se status of individuals given PUFAs is assessed before and during intake; Se supplements should only be given when serum and/or erythrocyte Se are reduced.


Characterization of 6-hexadecanoylamino-4-methylumbelliferyl-beta-D- galactopyranoside as fluorogenic substrate of galactocerebrosidase for the diagnosis of Krabbe disease. 6-Hexadecanoylamino-4-methylumbelliferyl-beta-D-galactopyranoside (HMGal) has been shown to be a specific fluorogenic substrate of galactocerebrosidase and to facilitate the simple enzymatic diagnosis of Krabbe disease in human patients and in twitcher mice. HMGal hydrolysis at pH 4.5 is optimally stimulated by sodium taurocholate (0.25%) and oleic acid (0.05%) with a Km of 0.150, 0.04 and 0.03 mM, respectively for control mouse kidney, human fibroblasts and leukocytes. In control samples, the specific activity (nmol/mg prot./h) for HMGal is higher than for the natural substrate, galactocerebroside, and is severely deficient in the twitcher mouse and in patients with Krabbe disease. Comparative investigation of galactocerebrosidase activity in fibroblasts, leukocytes and brain with radioactive and fluorogenic substrates reveals a good agreement between the results of the two methods. Galactocerebroside (Gal-Cer) is a competitive inhibitor of HMGal hydrolysis in mouse kidney homogenates while GM1-ganglioside has no inhibitory effect in the same assay system. The sensitivity and specificity of this fluorogenic substrate for galactocerebrosidase provides a simple and rapid method for the diagnosis of Krabbe disease, and for the purification of this enzyme from normal tissues.


Effects of unsaturated and saturated dietary plant sterols on their serum contents. Rapeseed oil fed to 24 hypercholesterolemic patients (50 g/day) reduced serum cholesterol (-8.5%) and cholestanol concentrations but increased those of campesterol and sitosterol. Continuation of rapeseed oil alone or with added sitosterol (625 mg/day) or sitostanol (630 mg/day) had no further effect on serum cholesterol. Rapeseed oil with sitosterol increased further its own proportion to cholesterol in serum but reduced that of campesterol while rapeseed oil with sitostanol reduced the proportions of both sitosterol and campesterol proportionately to the pretreatment values. The changes in the campesterol and sitosterol proportions were negatively and positively related to each other during the sitosterol and sitostanol additions, respectively. Thus, concentrations of unsaturated plant sterols in serum reflect their dietary intakes, saturated plant sterols are virtually not absorbed, plant sterols interfere with absorption of unsaturated structurally different plant sterols and cholestanol, and plant sterol-induced reduction of sterol absorption may be positively related to absorption efficiency of sterols.


Gastroparesis: diagnostic and therapeutic strategies. Impairment of gastrointestinal motility is common among patients with chronic dyspepsia. Gastroparesis can lead to devastating clinical consequences including malnutrition, weight loss, metabolic acidosis and psychological dysfunction. In this article, the current concepts of gastric motor function are reviewed and the diagnostic and treatment modalities of gastroparesis are discussed in detail.


Infantile hypertrophic pyloric stenosis. This is a world-wide disease, more common in Caucasians and probably on the increase. The aetiology remains very poorly understood. Presentation is between 2 and 8 weeks with vomiting, classically projectile, in an otherwise well hungry child. The diagnosis can confidently be made in most cases by a careful test feed; ultrasound and barium meal examinations are only required for difficult cases. Intravenous fluid replacement is essential prior to surgery and 24 h or longer may be required to correct acid base disturbances and enable safe general anaesthesia. Pyloromyotomy (Ramstedt's operation) remains the only satisfactory treatment, our mortality rate for this is 0.4%. Occasional vomits occur postoperatively in over half of patients but we are sceptical of the value of graded postoperative feeding regimens. There are no known long-term sequelae to surgery and this remains a most rewarding paediatric surgical condition to treat.


Polyps of the stomach and duodenum: significance and management. Gastric and duodenal polypoid lesions are almost always diagnosed incidentally and constitute a clinical problem for treatment and follow-up. The histologic types of polypoid lesions in stomach and duodenum are described, as well as the clinical setting in which they are found. Endoscopy and directed biopsies, but particularly diathermic snare polypectomy, are essential to establish a certain histologic diagnosis. Guidelines are given for treatment and follow-up.


Raised liver enzymes in asymptomatic patients: investigation and outcome. Asymptomatic patients with raised liver enzymes are frequently encountered in clinical practice. The commonest lesion in such patients appears to be fatty liver, which may be found in those only modestly overweight. Proven treatments other than abstention from alcohol and weight loss are available for approximately 20% of asymptomatic people with abnormal liver enzymes. However, if experimental therapies are taken into account this would rise to over 50%, making an early accurate diagnosis important. Most conditions can be diagnosed non-invasively, especially in those people with markedly abnormal transaminases. The recent introduction of new non-invasive tests decreases the need for liver biopsy for diagnostic purposes, however liver biopsy retains an important role in establishing patient prognosis and response to treatment.


Lactic acid bacteria in the gut in normal and disordered states. The human gut flora is a complex and finely balanced ecosystem which plays an important protective role in humans. Although relatively stable, its composition may be altered in various disease states and by the administration of antimicrobial agents. Preparations containing viable lactic acid bacteria of human origin appear to have value in restoring normal microbial function and alleviating symptoms in some patients with gastrointestinal infection and other conditions.


Insulin-like growth factor 1 and growth hormone in chronic liver disease. Somatomedins or insulin-like growth factors (IGF) are peptides synthesized in the liver. IGFs have different anabolic and metabolic actions and are important in normal growth and development. The concentration of insulin-like growth factor 1 (IGF-1) is low in patients with chronic liver disease mainly due to the decreased liver function. Low levels of somatomedins are also seen in patients with growth hormone (GH) insufficiency, renal impairment, and malnutrition. GH stimulates the production of IGF-1, and both are part of a negative feedback system acting on hepatic, pituitary, and hypothalamic levels. The basal and stimulated GH concentration is pathologically elevated in patients with chronic liver disease and may be due to a disturbed regulation. Alterations in liver IGF receptors in patients with chronic liver disease still require investigation as they may be important for the liver function.


Fish oil feeding selectively attenuates contractile responses to noradrenaline and electrical stimulation in the perfused mesenteric resistance vessels of spontaneously hypertensive rats. 1. The mechanism of the antihypertensive effects of n-3 fatty acids were examined in spontaneously hypertensive rats (SHR) by feeding 'Max EPA' fish oil or hydrogenated coconut oil and determining the responses of perfused mesenteric resistance vessels to various contractile agents and peri-arterial nerve stimulation. 2. Fish oil feeding for 4 weeks caused a decrease in the responses to exogenous noradrenaline and electrical nerve stimulations but had no significant effect on vasopressin and KCl (80 mmol/L) induced contractions. 3. These results provide direct evidence for specific attenuation of vascular responses to sympatho-adrenal stimulation in resistance vessels following fish oil feeding and may account for the antihypertensive effects seen in humans and in some forms of hypertension in rats.


Propofol anaesthesia in malignant hyperpyrexia susceptible swine. 1. Malignant hyperpyrexia (MH) is an inherited muscle abnormality that presents clinically as a syndrome of life-threatening complications during general anaesthesia. 2. Propofol is a new sedative hypnotic used for the induction and maintenance of anaesthesia. 3. Propofol did not induce MH in five susceptible pigs. Propofol did not induce contracture in isolated MH susceptible muscle but did modify halothane, caffeine and KCl contractures.


Cardiovascular habituation to emotional stress in Lyon hypertensive rats. 1. Intra-aortic blood pressure was recorded continuously in freely moving genetically hypertensive (LH), normotensive (LN) and low blood pressure (LL) rats of the Lyon strain during two 11 h periods (08:00-19:00 h). During the first period (control), the animals were left undisturbed and during the second period (stress), a jet of air was applied for 20 min every hour. Urine was collected simultaneously and analysed for its content in norepinephrine and epinephrine. 2. The first exposure to the stressor induced larger increases in blood pressure and heart rate in LH than in LN and LL rats. However blood pressure and heart rate responses to the 10 following stressors decreased in LH rats while they remained stable in LN and LL animals. 3. Repeated stress exposure induced significant increases in epinephrine excretion in both LN and LL but not in LH rats. 4. It is concluded that LH rats exhibit marked cardiovascular habituation to repeated stress. Taken together with the lack of stress-induced sympathoadrenal activation, this suggests a reduced level of emotional responsiveness in Lyon hypertensive rats.


Renal handling of endogenous lithium in experimental diabetes mellitus in the rat. 1. The usefulness of determining the renal handling of endogenous lithium as a marker of proximal tubular sodium reabsorption was assessed in streptozotocin induced diabetes mellitus in the Sprague-Dawley rat. 2. The clearance and fractional excretion of lithium were determined before and following the development of diabetes mellitus, and compared with measurements of proximal tubular reabsorption made directly using micropuncture techniques. Endogenous lithium was measured in order to avoid the toxic tubular effects of exogenously administered lithium salts. 3. Although a trend existed for a reduction in the fractional excretion of lithium in diabetic animals (1.8 +/- 0.3 vs 2.4 +/- 0.5%; P greater than 0.20), this did not reach statistical significance and did not accurately reflect the change in directly measured tubular Na reabsorption. 4. The decrease in proximal tubular Na reabsorption demonstrated in diabetic animals treated with phlorizin was not significantly reflected in the fractional lithium excretion, although again a corresponding trend was evident (1.9 +/- 0.8 vs 0.6 +/- 0.2%; P greater than 0.10. 5. In summary, the significant alterations in tubular Na handling in diabetes mellitus, previously demonstrated directly using micropuncture techniques, are not reflected in the renal handling of endogenous lithium. This indirect method is inadequate to assess proximal tubular Na transport in experimental diabetes mellitus.


Enalapril decreases plasma noradrenaline levels during the cold pressor test in human hypertensives. 1. The effects of the angiotensin-converting enzyme (ACE) inhibitor enalapril on the responses of blood pressure and plasma catecholamine levels to the cold pressor test in human hypertensives were examined. 2. Systolic and diastolic blood pressure decreased significantly after treatment with enalapril (5 mg/day for 4 weeks) as did the resting level of plasma noradrenaline. 3. The cold pressor test induced a rise in blood pressure and plasma noradrenaline levels. After 2 and 4 weeks enalapril treatment, the rises in the plasma noradrenaline level and systolic and diastolic pressure due to cold pressor test were reduced significantly. 4. These results suggest that ACE inhibition has a sympatho-inhibitory effect. One possible explanation is that enalapril reduces angiotensin II formation thus decreasing the activation of release-enhancing angiotensin II receptors on postganglionic sympathetic nerve endings.


Effects of repeated doses of pseudoephedrine on blood pressure and plasma catecholamines in normal subjects and in patients with phaeochromocytoma. 1. Increases in blood pressure (BP) and in plasma noradrenaline concentration (NA) were observed after two doses of a non-prescription decongestant containing pseudoephedrine (PE) in two of three patients with phaeochromocytoma, before but not after removal of the tumour. The pressor response was terminated by oral phenoxybenzamine, and modified by prior exposure to this drug. 2. In eight normal subjects administration of the same two doses prevented falls in BP and in NA usually seen with prolonged recumbency, but neither BP nor NA increased. However, a pressor response was observed in a normal subject with a strong family history of hypertension. 3. Exposure to PE in non-prescription decongestants is not without risk in hypertension.


Is isolated systolic hypertension a 'white coat' phenomenon in the elderly? 1. Repeated clinic blood pressure measurement was compared with non-invasive ambulatory blood pressure (ABP) monitoring in 10 elderly subjects with isolated systolic hypertension (ISH) and 11 normotensive controls (NT). 2. Subjects were assessed on four occasions at weekly intervals. None was receiving antihypertensive or vasoactive medication. 3. Mean clinic blood pressure was consistently higher than mean daytime ABP in both clinical groups. This effect was greater for systolic (SBP) than diastolic blood pressure (DBP) and in the ISH group compared with the NT group. The reproducibility of the clinic minus ABP difference was high in both groups; the mean +/- s.d. of the differences was 26 +/- 15/9 +/- 2 mmHg in the ISH group and 7 +/- 18/8 +/- 9 mmHg in the controls. 4. ABP readings were normally distributed for both SBP and DBP in both groups. In the ISH group, the frequency distribution of SBP readings was shifted to the right whilst the distribution of DBP readings overlapped that of the NT subjects. 5. These results suggest a pressor response may largely account for the elevated SBP seen in elderly subjects with sustained ISH based on casual readings.


Sample size requirements for clinical trials of isolated systolic hypertension. 1. This study investigated components of blood pressure variability in elderly subjects with isolated systolic hypertension (ISH) using both ambulatory blood pressure monitoring (ABPM) and casual clinic blood pressure measurement. These were then used to determine sample size requirements for clinical trials of different designs. 2. Eleven elderly subjects not receiving antihypertensive medication were seen on four occasions at weekly intervals. On each occasion blood pressure was measured in the clinic and then for 24 h using a non-invasive ABPM device. Nested analysis of variance was used to calculate the 'between subject' and 'between subject within occasion' components of blood pressure variability. 3. Increasing the number of readings or occasions where measurement was performed in a parallel group trial only reduced the variability substantially when the number of subjects involved was less than 50. Use of a cross-over design substantially reduced the sample size required. 4. ABPM appears most useful as a strategy for reducing sample size in parallel group trials in ISH involving small numbers of subjects measured on one occasion.


Concurrence of primary aldosteronism and renal artery stenosis. 1. An unusual clinical case is described in which renal artery stenosis (RAS) was found to coexist with adrenocortical hyperplasia, resulting in hypertension. 2. Partial relief of the hypertension was achieved by correction of RAS, and then further relief by extirpation of one adrenal gland affected by unilateral hyperplasia, in interventions 8 months apart. 3. Biochemical features typical of primary hyperaldosteronism were observed both before and after RAS repair but were not present after unilateral adrenalectomy. 4. The association of these two lesions could have occurred by chance, through genetic linkage, or by progression from RAS to tertiary aldosteronism.