The acidosis of cholera. Contributions of hyperproteinemia, lactic acidemia, and hyperphosphatemia to an increased serum anion gap

To study the metabolic acidosis that occurs during the diarrhea of cholera, we examined the serum anion gap in 21 patients with hypovolemic shock due to Vibrio cholerae infection. Measurements of serum electrolytes, as well as divalent cations and the anionic contributions of serum proteins, lactate, phosphate, and serum creatinine, were made at the time of admission, after rehydration, and during convalescence. At the time of admission, the mean serum concentration of sodium was 134.8 mmol (meq) per liter, that of chloride was 103.2 mmol per liter, and that of bicarbonate was 11.4 mmol per liter; the mean anion gap was 20.2 mmol per liter. The mean serum creatinine concentration was 2.48 mg per deciliter. The low serum bicarbonate level and the high serum anion gap were corrected by rehydration. The increased serum anion gap was caused by hyperproteinemia, lactic acidemia, and hyperphosphatemia, with anionic contributions to the rise in anion gap estimated as protein, 5.5 meq per liter; lactate, 2.5 meq per liter; and phosphate, 2.5 meq per liter. The hyperproteinemia was attributed to dehydration, the lactic acidemia to shock, and the hyperphosphatemia to acidosis and transient renal failure. The mean concentrations of serum calcium and magnesium were slightly elevated but did not affect the increased anion gap. These results indicate that severe cholera causes acidosis with relatively little change in serum chloride but an increased serum anion gap. The acidosis is more profound than would be expected on the basis of stool losses of bicarbonate, because of superimposed lactic acidemia and renal failure.     

Ultrastructural features of diethylnitrosamine-induced lesions in the mouse liver

Mice were given a single dose of diethylnitrosamine (DEN). After 12 and 15 months, the ultrastructural features of simple hepatic nodules and defined hepatocellular carcinomas were compared. The main difference between these two lesions is the presence of highly convoluted membranes in the hepatocytes of the carcinomas. A third population of nodules was also found which could not be easily classified at the light microscope level into either simple hepatic nodules or carcinomas. Ultrastructural examination of these lesions showed them to have areas resembling both simple hepatic nodules and carcinomas. Within both these areas hepatocytes with convoluted plasma membranes were observed. Changes in membrane pattern may be indicative of an altered cell growth pattern and the acquisition of invasive or metastatic properties. This provides further evidence suggesting that a sub-population of cells can be identified which has the potential to develop into overt carcinoma.     

Automated DNA fingerprinting analysis of Mycobacterium tuberculosis using fluorescent detection of PCR products.

DNA fingerprints of Mycobacterium tuberculosis are produced by restriction fragment length polymorphism analysis of the insertion element IS6110. We modified a PCR-based subtyping method, mixed-linker PCR with fluorescent-labeled IS6110-specific oligonucleotides, to demonstrate rapid, automated, and unattended electrophoretic analysis. Variation in band sizing (normally occurring with fragment mobility), an artifact of lane-to-lane and gel-to-gel differences, was controlled with an internal lane standard, resulting in accurate and precise DNA sizing. By using this method, fingerprint analysis can be performed using actual fragment length rather than estimated position analysis.     

Comparison of isolation of Haemophilus vaginalis (Corynebacterium vaginale) from peptone-starch-dextrose agar and Columbia colistin-nalidoxic acid agar.

A total of 447 cervical or vaginal specimens were inoculated in parallel onto peptone-starch-dextrose (PSD) and Columbia colistin (10 mg/ml)-nalidixic acid (15 mug/ml) (CNA) agar and were incubated for 48 h at 35 degrees C in an atmosphere with 2 to 10% CO2. One hundred (22.4%) of the cultures were positive for Haemophilus vaginalis. Forty-eight of the isolates were recovered from both PSD and Columbia CNA agar, five from PSD only, and 47 from Columbia CNA agar only (P less than 0.001). On Columbia CNA agar, 76 of the isolates were detected after 24 h of incubation, and the remainder were detected within 4 days of incubation.     

Lung injury induced by antibody fragments to angiotensin-converting enzyme.

Rabbits given goat anti-rabbit angiotensin-converting enzyme antibodies or derived antibody fragments develop rapidly fatal pulmonary edema. Endothelial cell injury is manifested by bleb formation and the disintegration of cell membranes. Platelets are found along the injured endothelium and leukocytes block capillary lumens. The pathologic features are similar when immune IgG, F(ab')2, or Fab are given. In vitro studies of complement activation show that solubilized, purified angiotensin-converting enzyme alone activates C1, with consumption of C4 and C3. Addition of immune IgG plus converting enzyme enhances this activation. F(ab')2 plus enzyme enhances only C3 consumption, while Fab with enzyme produces no additional complement utilization. Thus, while complement activation may be involved in the pathogenesis of injury induced by IgG or F(ab')2, the mechanism of Fab-induced endothelial injury remains unclear.     

Heterogeneity of hepatocyte antigen expression in rat liver carcinogenesis: concordance between neoplastic nodules and tumours.

Fischer F344 rats were given a cyclical diet of 0.06% 2-acetylaminofluorene (AAF), which progressively induced oval cell proliferation, cirrhosis and hyperplastic (or neoplastic) nodules. Primary liver tumours developed from 7 months after ceasing the diet. Liver samples taken during and after AAF administration and specimens of primary tumours were processed into frozen sections and examined microscopically for morphological changes in cell populations, stained histochemically for gamma-glutamyl transpeptidase (GGTase) and four phosphatases, and stained by the immunoperoxidase technique for the presence of antigens detected by seven anti-liver cell monoclonal antibodies and monoclonal antibodies to six oncoproteins. During and after AAF treatment several of the anti-liver antibodies revealed foci of aberrantly or heterogeneously-stained cells, although anti-oncoprotein antibodies showed no consistent changes. Foci of cells positive for GGTase and heterogeneous for adenosine triphosphatase (ATPase) were also seen. Nodules invariably showed heterogeneous antigenicity, raised GGTase and abnormal ATPase expression. Primary tumours exhibited varying degrees of positivity, negativity and heterogeneity with the anti-liver monoclonal antibodies, and all were positive for GGTase. Comparison between various parameters and different lesions showed the greatest concordance between nodules and tumours, suggesting that nodules are probably the precursors of malignant tumours in this system.     

Quality control in cervical cytology

From surveys conducted by the authors it is concluded that the best and most acceptable quality control methods in cytology are those from within the laboratory. Most of these have results which can be reported centrally. Where the overall control and codes of practice are high, there the results are the most reliable, as sources of error from whatever cause are quickly brought to light. These conclusions are illustrated by data from the five centres and correlated in the tables.     

Characterization of an SAV organism and proposal of Mycobacterium triplex sp. nov.

Polyphasic taxonomic methods were employed to characterize a new species of slowly growing, nonpigmented mycobacteria. We propose the name Mycobacterium triplex sp. nov. for this new taxon. Conventional identification testing demonstrated a group of similar organisms that were geographically widespread in the United States. Commercially available nucleic-acid probes specific for the Mycobacterium avium complex were unreactive for these strains. High-performance liquid chromatography analysis of the mycolic acids revealed mycolate profiles that closely resembled Mycobacterium simiae. Comparative 16S rRNA sequence data confirmed the phylogenetic relationship of the strains with the slowly growing mycobacteria. Representative-type strains have been deposited in the American Type Culture Collection as strain ATCC 700071 [corrected].     

Behavior in chimeric mice combining differently behaving strains

A/J and C57BL/6J mice behave differently in tests for alcohol preference, open-field activity, defecation in the open field, cricket attacking, and rope climbing. Chimeric mice, i.e., mice containing both A/J cells and C57BL/6J cells, were constructed and tested for these behaviors. Patterns of behavior among A/JC57BL/6J chimeras are such as to suggest that none of these behavior differences is controlled by a single cell or clone and that the same cell population that gives rise to the strain difference in alcohol preference also gives rise to the differences in open-field activity and defecation, while separate cell populations control cricket killing and rope climbing.This research was supported by Research Grants AA 00388 and HD 03015 to M. N. N. and MH 18996 to K. B. Computing assistance was obtained from the Health Sciences Computing Facility, UCLA, supported by NIH Special Research Resources Grant RR-3.