Biomedical subjects
J Bernstein
Publications and source records attributed to J Bernstein.
[Urethral stenosis following cardiac surgery].
87 cases of urethral stenosis were treated over a two year period. This study was motivated by the high incidence of urethral stenosis after cardiac surgery. The patients were classified into four groups; urological surgery, cardiovascular surgery, medicine and other surgical specialties. The mean age was 60. It is easy to explain the development of urethral stenosis following endoscopic urological surgery, but rather more difficult, following cardiac surgery. The patients undergoing cardiac surgery were compared with those having a transurethral resection of the prostate. Neither traumatic catheterisation, urinary infection, prolonged catheterisation nor any factors specific to cardiac surgery could be implicated. The number of stenoses of the penile urethra was similar to the number of stenoses in the bulbar urethra. The critical period is within the first three months following surgery. Two hypotheses have been proposed to explain the pathogenesis of urethral stenosis after cardiac surgery: a hypersensitivity of the urethral mucosa combined, perhaps, with episodes of ischaemia. In order to verify the first hypothesis, the authors undertook a prospective study. Two groups of patients were chosen at random: 45 had a urethral catheter, 28 had a cystocatheter; 4 cases of urethral stenosis developed after the urethral catheter and there were no cases with the cystocatheter.
Estimating health risks a plus.
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Synergistic toxicity of carbon tetrachloride and several aromatic organohalide compounds.
Subacute (20 days) oral administration of hexachlorobenzene (HCB) or the organohalide mixtures polybrominated biphenyls (PBB) or polychlorinated biphenyls (PCB) greatly increased th susceptibility of male rats to the toxic effects of carbon tetrachloride (CCl4). CCl4-induced acute growth retardation, renal tubular functional impairment and hepatocellular necrosis were quantitatively greater in rats pretreated with the aromatic organohalides than in naive rats. Pretreatment with HCB, PBB or PCB also reduced survival after i.p. administration of CCl4 and increased the severity of morphological liver injury. Despite functional impairment, only minor histological alterations attributable to CCl4 were detected in the kidney. CCl4 as well as HCB, PBB or PCB increased the lipid content of the liver, but not the kidney. CCl4 administration depressed energy-dependent accumulation of organic ions by renal cortical slices in vitro in a dose-dependent manner and increased the basal rate of respiration of renal cortical tissue in vitro. It is concluded from these results that exposure to certain commercial aromatic organohalides can greatly alter organ response to toxicants such as CCl4.
Steroid-dependent nephrotic syndrome.
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Cystic kidneys in a patient with oral-facial-digital syndrome type I.
A cystic renal lesion is described in a girl with oral-facial-digital syndrome, type I. Excretory urography was normal at 1 yr of age; however, flank masses, hypertension, and renal failure were discovered at 11 yr of age. Bilateral nephrectomies were performed prior to renal transplantation. The renal cortex was replaced by large cysts. The cysts were lined by flattened nondescript epithelium and many contained glomerular tufts. Twenty renal cysts were aspirated, and the cyst fluid analyzed for sodium, potassium, creatinine, and osmolality. The concentration of solutes in the cyst fluid was comparable to plasma values. The pathologic features and pattern of cyst solute concentration appear to distinguish the cystic renal lesion in oral-facial-digital syndrome from the more common adult-type polycystic kidney disease.
Who leaves--who stays: residency policy in housing for the elderly.
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Determining the phoM map location in Escherichia coli K-12 by using a nearby transposon Tn10 insertion.
A phoR strain was constructed with transposon Tn10 inserted near the phoM+ locus. This was done without any prior knowledge of the phoM map location. Subsequently, we defined the phoM map position by screening tetracycline-sensitive (Tcs) derivatives for mutants which were both alkaline phosphatase negative (ther phoR phoM double mutant phenotype) and auxotrophic simultaneously. Some of these mutants were Thr-. Bacteriophage P1-mediated transductions were used to confirm that phoM and its nearby Tn10 insertion were closely linked to thr. Unexpectedly, 7 of 10 mutants analyzed also had mutations unlinked to the phoM-thr-Tn10 region. These may represent a new type of Tn10-promoted molecular event which is caused by transposition of a Tn10 end (IS10).
Minimal change nephrotic syndrome. Histopathology and steroid-responsiveness.
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Comparison of the composition of faecal fluid in Crohn's disease and ulcerative colitis.
We determined the ionic composition of faecal fluid from 13 patients with Crohn's disease limited to the colon, 10 with diffuse ulcerative colitis, and eight with ulcerative proctitis. The Crohn's and colitis groups had similar proportions of colon surface involved radiographically and similar 24 hour faecal weights. However, Crohn's patients' faecal fluid had arithmetically lower mean sodium and statistically lower mean chloride (34.8 mmol/l +/- 16.2 SD vs. 53.1 mmol/l +/- 23.1 SD) and higher potassium (49.2 mmol/l +/- 20.2 SD vs. 33.0 mmol/l +/- 13.8 SD) concentrations (p less than 0.05 for each) and much higher osmolality (487.1 mOsmol/kg +/- 87.1 SD vs. 341.1 mOsmol/kg +/- 88.9 SD, p less than 0.001). Separation of these patients using the faecal osmotic gap agreed with the clinical classification in 86% of cases. The diarrhoea of proctitis patients had a nearly normal ionic composition which was clearly distinguishable from that of diffuse colitis. These results suggest differences in the composition and perhaps the pathogenesis of the diarrhoea of Crohn's and ulcerative colitis. The composition of fluid may prove a useful, non-invasive method for classifying patients with inflammatory bowel disease and, in ulcerative colitis, determining the extent of the inflammatory process.
The potential for bacterial growth with dextran.
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Death and disability agreements. How to preplan to protect your interests.
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The role of the lung in the metabolism of ethanol.
Rat lung slices incubated in a Krebs ringer bicarbonate buffer were able to metabolize ethanol at rates which are dependent on the concentration of ethanol used. This metabolic system showed an apparent Km for ethanol of the order of 12 mM and a Vmax of 450 mumoles/g lung x hr. At 10 mM ethanol, lung slices metabolized 232.74 +/- 31.67 mumoles/g lung x hr whereas liver slices showed rates of metabolism which were ten times lower. The ability of the lung to metabolize ethanol was not observed in the absence of oxygen. Calculations indicate that the lungs could account for about 30% to 40% of the in vivo rates of ethanol metabolism.
Leydig-Sertoli cell tumour in the postmenopausal female. A case report.
A patient with a Leydig-Sertoli cell tumour of the ovary is described. This rare lesion coexisted with three other primary neoplastic lesions, namely an adenocarcinoma of the colon, an ovarian fibroma, and leiomyomas of the uterus. A discussion of the unusual ovarian lesion and a short review of the literature are presented.
Disaccharidase-deficient animals have normal ultrastructure of intestinal brush border membranes.
The intestinal disaccharidases, lactase, sucrase-isomaltase complex, and glucoamylase are proteins intimately associated with the brush-border membrane of the epithelial cell. These three enzyme activities are found in the intestine of the adult rat; lactase and glucoamylase activities are primarily associated with the intestine of the infant rat. Only glucoamylase and isomaltase activities are detected in the intestine of the California sea lion, Zalophus californianus. The activities of these enzymes are detected only in villus cells, and not in crypt cells. We have carried out electron microscopic studies of negatively stained brush-border preparations of intestinal crypt and villus cells; from the intestine of the 10-day-old rat and from that of the California sea lion. The density of the knob-like structures protruding from the brush-border membranes was not significantly different in any of these preparations. The diameter of the knobs on the preparations from crypt cells was smaller than the diameters of the knobs found on membranes prepared from the other sources. These data are discussed in terms of the relationship between the presence of knob structures and disaccharides activities associated with the brush-border membranes.
Induction of drug-metabolizing enzymes and toxicity of trans-stilbene oxide in rat liver and kidney.
The effect of trans-stilbene oxide (TSO) on organ function and morphology and on drug-metabolizing enzymes was determined in male Sprague-Dawley rats. TSO (300 or 600 mg/kg) was administered i.p., once daily for 5 consecutive days. At a dose of 3400 mg/kg, TSO did no alter body weight, but increased liver weight. The higher dose (600 mg/kg) markedly decreased body weight. TSO treatment (300 mg/kg) induced several drug-metabolizing enzymes. Epoxide hydrolase activity was enhanced in the liver, kidney and lung. In contrast, arylhydrocarbon hydroxylase activity was not significantly altered. Glutathione S-transferase activity, with 1-chloro-2,4-dinitrobenzene as substrate, and uridine diphosphoglucuronyl transferase activity, with p-nitrophenol as substrate, were also increased in the liver and kidney after TSO treatment. It appears that TSO induces hepatic and renal enzyme activities in a similar manner. Treatment with the higher dose of TSO depressed accumulation of p-amino-hippurate by renal cortical slices and increased blood urea nitrogen concentration. Histological examination of kidney sections after treatment with TSO revealed no abnormality. The lower dose led to negligible alteration in liver and the higher dose resulted in mild to moderate hepatic cellular.
Alterations in glomerular RNA in diabetic rats: roles of glucagon and insulin.
Incorporation in vivo of labeled orotate into RNA and total nucleotides was measured in isolated glomeruli and whole renal cortex. In 2-day diabetic animals, glomerular RNA was increased, and there was greater incorporation of orotate into total nucleotides and RNA as compared with controls. Insulin reversed the exaggerated incorporation at infusion rates that corrected hyperglucagonemia without reducing plasma glucose and with only minimal changes in insulin concentrations. The addition of glucagon to insulin infusions reproduced the increased incorporation observed in untreated diabetics. Similar changes occurred in renal cortex, where differences in orotate incorporation into nucleotide precursors seemed to be the main cause for alterations in RNA labeling. Isotope incorporation in glomeruli correlated positively with plasma glucagon, but not with insulin or glucose concentrations. Although in 7-month diabetic animals orotate incorporation into RNA was less than in controls, probably as a consequence of renal disease, 24-hour insulin infusion decreased it further. Our results confirm that in the diabetic kidney, abnormal uracil nucleotide metabolism and increased cellular content of RNA are demonstrable in glomeruli as in the renal cortex. These changes appear to be related directly to hyperglucagonemia.
Formant-based representation of auditory similarity among vowel-like sounds.
Can the acoustic properties of vowels, in particular, formant frequencies, and formant amplitudes, be scaled so that the auditory relations among vowels are representable by their positions in a formant frequency space? Experiments are described in which carefully selected sets of five-formant vowel-like sounds were presented to listeners. Auditory judgements were elicited sufficient to evaluate the conformity of steady state vowel perception with various algebraic forms. Test results demonstrate that if intervowel distances are organized on a formant-by-formant basis, as for example in the commonly used Euclidean distance metric, no scaling of listeners' responses using a formant-based distance, two factors are required for each formant: Scaled formant amplitude levels must be included in the representation, and the difference of the scaled formant frequencies must be weighted by the formant amplitude levels.