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Biomedical subjects

A Novick

Publications and source records attributed to A Novick.

68 records · Page 4Linked to original sources
PubMed1973

Organic solvents as probes for the structure and function of the bacterial membrane: effects of ethanol on the wild type and an ethanol-resistant mutant of Escherichia coli K-12.

The effects of ethanol on the growth of a wild-type Escherichia coli K-12 are described. These effects include a reduction of the steady-state growth rate and an interference with the division process. They appear as an immediate response to the addition of ethanol and are rapidly reversed by removal of ethanol. Mutants were selected that could grow at a concentration of ethanol that stopped wild-type growth. The growth of one of the mutants we studied (strain S9L100) is stimulated by the presence of ethanol, methanol, or dimethyl sulfoxide. This strain exhibits pleiotropic growth defects including abnormal cell division and morphology. It also appears to have an altered lac permease function which is not due to a mutation in the Y gene itself. We conclude that this mutant has an altered membrane and that the membrane defect may be the cause of the abnormal growth properties. The use of compounds which serve as general membrane perturbants and mutants resistant to these perturbants form a system accessible to both genetic and physical-biochemical techniques.

Bacterial Proteins↗
PubMedDate not supplied

Reliability of torque range of motion: a preliminary study.

The clinical reliability of torque range of motion (TROM) has not been tested. This preliminary review was performed to determine the intra- and interrater reliability of TROM. The proximal interphalangeal joints of the index and middle fingers of 14 normal subjects, 56 digits, were tested by applying extension forces of 200 g, 400 g, 600 g, and 800 g. Data were collected using both the hand-held Haldex orthotic gauge with the dial goniometer (manual) and the cantilever-beam force transducer and electrogoniometer (digital) as testing instruments. The testing order of digits, sides, and devices was randomized and tested separately by three different test teams. Results of the analysis of variance showed a significant difference of the means between raters at all force levels (p < 0.0001) and between instruments at 600-g and 800-g forces (p < 0.01). The Pearson product-moment correlation coefficient test, used to test the consistency, resulted in moderate consistency of measures of intrarater reliability between trials, and between instruments used (digital and manual). Intraclass correlation coefficients (ICCs) were calculated with results that were nearly identical to those of the Pearson. Intrarater reliability was in more consistent agreement at the 600-g and 800-g levels. There was significantly high agreement between the tests of tester B, compared with moderate correlations of the tests of testers A and C.

Adult↗
PubMedDate not supplied

Responses of the stenosed and contralateral kidneys to [Sar1, Thr8] AII in human renovascular hypertension.

To better define the intrarenal hemodynamic effects of angiotensin in human renovascular hypertension, 10 patients underwent renal hemodynamic and functional measurements before and during infusion of a competitive angiotensin analog, [Sar1, Thr8] AII. Eight had technically satisfactory split function studies. Despite a fall in mean arterial pressure (132 +/- 6 to 121 +/- 6 mm Hg, p less than 0.05) and humoral changes consistent with angiotensin-mediated hypertension, the intrarenal effects of this analog were commonly those of an angiotensin agonist, producing vasoconstriction and sodium retention. This was quantitatively greatest in the contralateral kidney, whose preinfusion sodium excretion (86 +/- 30 microEq/min vs 25 +/- 9 microEq/min, p less than 0.02) and glomerular filtration rate (76 +/- 7 ml/min vs 41 +/- 7 ml/min, p less than 0.01) were higher than the stenotic kidney. In some cases, an increase in renal blood flow and rise in sodium excretion were evident during angiotensin blockade, suggesting a tonic intrarenal action of angiotensin. Although renin vein renin values differed markedly between the stenotic and contralateral kidney (ratio = 2.05 +/- 0.30), relative changes in effective renal plasma flow were correlated (r = 0.84: p less than 0.01) during infusion of this analog. These results underscore the differences in sensitivities between vascular beds to the effects of angiotensin II and the major role of the contralateral kidney in renal function and sodium homeostasis in human renovascular hypertension.

Adult↗
PubMedDate not supplied

NMP22: a sensitive, cost-effective test in patients at risk for bladder cancer.

BACKGROUND: This study was designed to determine the clinical utility of NMP22 as a urinary marker for the early detection of transitional cell carcinoma (TCC) of the bladder in patients with hematuria or other indications for risk of malignancy. Its utility will be measured by sensitivity and specificity estimates as compared to cystoscopy. Since urine cytology is normally collected in this population of patients, it will also be analyzed and compared to cystoscopy. MATERIALS AND METHODS: Each patient submitted a single voided urine which was stabilized with the NMP22 urine collection kit or preserved in the appropriate cytology medium for cytopathologic testing. All patients provided the urine samples before cystoscopic exam. Of the 146 patients, there were 43 patients with microscopic hematuria and 13 with gross hematuria. Other indications for cystoscopy included unexplained or medically refractory voiding. There were 8 patients with biopsy confirmed bladder cancer and 138 patients with benign conditions of the bladder. RESULTS: The median NMP22 value for the bladder cancer malignancies was 27.8 U/mL (95% Confidence interval: 10.5-32.1 U/mL). The median NMP22 value for the benign conditions of the bladder was 3.25 U/mL (95% Confidence interval: 2.5-3.8 U/mL). The urinary NMP22 values from the bladder cancer group was statistically different (p < .000001 Mann-Whitney U test) than the NMP22 values in the benign conditions group. Using a reference value of 10.0 U/mL, the sensitivity of NMP22 was 100% with a specificity of 90%, while cytology had a sensitivity of 25% and a specificity of 100%. Due to its high negative predictive value, using NMP22 alone could have eliminated 124 cystoscopies with total savings ranging from $24,824 to $63,264 depending on the type of insurance carrier. CONCLUSIONS: This study indicates that urinary NMP22 is a useful, cost-effective marker for the early detection of bladder cancer.

Biomarkers, Tumor↗
PubMedDate not supplied

Standards of care.

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Acquired Immunodeficiency Syndrome↗