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Biomedical subjects

S Katz

Publications and source records attributed to S Katz.

At least 217 records · Page 12Linked to original sources
PubMed1991

Liver bacterial clearance following hepatic artery ligation and portacaval shunt.

The reticuloendothelial system (RES) plays an important role in removing bacteria, endotoxins, and immune complexes from the circulation. Hepatic phagocytosis accounts for more than 80% of RES function. The dual hepatic blood supply (hepatic artery/portal vein) may be altered by pathologic states and surgical procedures. This study evaluates and compares the effect of hepatic artery ligation and portacaval shunt on hepatic trapping of viable Escherichia coli. Thirty rats were placed in three groups: Group I was composed of sham operated controls; Group II underwent end-to-side portacaval shunt (PCS); and in Group III, hepatic artery ligation (HAL) was performed. At 2 weeks following the operation 10(9) 35S-radiolabeled viable E. coli were injected via the tail vein. At 10 min, bacterial distribution in the different organs was determined. Tissue samples were processed for liquid scintillation counting. The final distribution of bacteria was calculated from the input specific activity (dpm/bacteria) and expressed as the mean percentage of injected viable E. coli per gram of tissue and per organ weight. There was a significant decrease of bacterial trapping by the liver in rats following PCS (Group II), 45.0 +/- 10.4% vs controls 77.1 +/- 3.73% (P less than 0.005). This was partially compensated for by a significant increase of bacterial trapping by the lung. The decreased clearance in PCS rats is due to a reduction in liver mass compared to that in controls. Bacterial localization in HAL (Group III) rats was similar to that in controls. These data show that PCS decreases hepatic clearance and increases pulmonary localization of viable E. coli. This phagocytic dysfunction may contribute to increased susceptibility to infection following portacaval shunt.

Animals↗
PubMed1991

Calcium transport activity of rat cardiac sarcoplasmic reticulum isolated in the presence of dithiothreitol.

We examined the effect of dithiothreitol (DTT) on the isolation and calcium transport properties of rat cardiac sarcoplasmic reticulum (SR). DTT at a concentration of 4 mM was included in the homogenization/initial isolation and the high-salt (KCl) buffers used in the preparation of the SR fraction. The inclusion of DTT in the SR isolation media did not affect the total amount of SR protein isolated from ventricular tissue. However, SR isolated in the presence of DTT exhibited a significantly increased (p less than 0.05) rate of calcium transport at free calcium concentrations ranging from 0.1 microM up to 2.0 microM, and a 26% increase in the apparent affinity of the SR calcium transport system for CA2+. DTT included in the calcium-transport reaction medium did not significantly alter the rate of SR calcium transport in SR preparations isolated in the absence or presence of DTT. These results demonstrate that functionally important sulfhydryl groups of the SR calcium transport pump may be oxidized during the isolation of the membrane fraction and that such oxidation can be reduced by including DTT in the isolation buffers.

Animals↗
PubMed1991

Purification and analysis of erythrocyte membrane Ca(2+)-ATPase from small samples of patient blood: application to cystic fibrosis.

A method is presented for the micro-scale isolation and characterization of erythrocyte membrane Ca(2+)-ATPase from small samples (7 mL) of whole human blood. Ca(2+)-ATPase isolated by this technique was more than 92% pure and showed calcium-activation characteristics similar to enzyme purified by standard macroscale procedures--viz maximal velocity of activation (VCA2+) = 15.5 +/- 1.2 mumol ATP hydrolysed/mg/min, and reciprocal of apparent affinity (KCa2+) = 0.73 +/- 0.15 microM free calcium (mean +/- SEM; n = 9). Using the isolation procedure described, purified Ca(2+)-ATPase could be prepared and assayed in a single working day. When the calcium-activation kinetics of cystic fibrosis erythrocyte membrane Ca(2+)-ATPase were reassessed using enzyme purified by this technique, VCa2+ and KCa2+ were not significantly different from normal values.

Adult↗
PubMed1991

Prostaglandin release by normal and osteomyelitic human bones.

The release of prostaglandin E (PGE) and prostacyclin (as 6-keto PGF1 alpha) by human osteomyelitic bone, compared with normal (control) bone, incubated in vitro was evaluated. Prostacyclin was the main arachidonic acid metabolite released by normal human bone, and similar quantities were released by osteomyelitic bone. However, PGE production was 5-30-fold higher in osteomyelitic bone, compared with control, thus becoming the major prostanoid in this disease. It is concluded that PGE production is probably involved in the inflammatory and/or bone resorption processes that occur in osteomyelitis.

6-Ketoprostaglandin F1 alpha↗
PubMed1991

Active life expectancy for 10,000 Caucasian men and women in three communities.

Active life expectancies (ALEs) were calculated using increment-decrement life table techniques for 10,000 Caucasian men and women from three geographic areas. This technique is more appropriate than the single decrement model originally used, and resulting ALE was substantially greater among initially independent men and women aged 65 years: from 9.3 for men and 10.6 for women to 11.3 to 13.0 for men and 15.5 to 17.1 for women. These increases may be attributable to factors other than the change of method, however, including the change in time from 1975 to 1982 and the change from one state to three communities. The sex differences suggest that the added years of life that women have enjoyed over men are neither solely added years of vigor nor solely added years of disability, but added years with the same mix of independence/dependence that the shorter-lived males experience. The age patterns suggest that at any age the future presents a relatively constant expectation of the total duration of dependency, and concordantly, as one ages, there is a relatively uniform decrease in the proportion of active life to remaining years.

Activities of Daily Living↗
PubMed1991

Early childhood and maternal antecedents to drug use.

In a longitudinal study, the substance use/abuse histories were obtained on a community sample of 640, (mean age of 24.9 years) randomly selected from the 8,000 Philadelphia black subjects who had been studied comprehensively from birth to seven years of age in the National Collaborative Perinatal Project (NCPP). Among other conclusions, it is postulated from some of the many significant associations found between early life variables and substance use/abuse in early adulthood, that an infant is at risk who has the following combination of characteristics and family situation: outgoing, responsive, assertive or impulsive, or willful, and who is in an unfavorable family environment, with a mother who is generally negative toward the infant, has a larger number of small children and has had more fetal deaths, in a generally poor social environment.

Adult↗
PubMed1991

Pancreatic pseudocyst: successful treatment by percutaneous external catheter drainage.

A pseudocyst of the pancreas in a 6-year-old girl persisted for 2 months despite bowel rest and nutritional support. Following percutaneous introduction of a catheter into the cyst under ultrasound guidance and external catheter drainage for 11 days, the pseudocyst resolved completely and permanently. Nonoperative percutaneous techniques for drainage of pancreatic pseudocysts in children may be an effective alternative to surgical intervention.

Catheters, Indwelling↗
PubMed1990

A non-specific Ca2+ (or Mg2+)-stimulated ATPase in rat heart sarcoplasmic reticulum.

ATPase activity in rat heart sarcoplasmic reticulum was stimulated in a concentration-dependent manner by both Ca2+ and Mg2+ in the complete absence of the other cation. Increasing concentrations of Mg2+ produced an apparent inhibition of the Ca2(+)-dependent ATP hydrolysis. CDTA (trans-1,2-diaminocyclo-hexane-N,N,N',N'-tetraacetate) had no effect on these responses. The results indicate the presence of a low affinity non-specific divalent cation-stimulated ATPase in rat heart sarcoplasmic reticulum. However, sarcoplasmic reticulum vesicles transported Ca2+ with a high affinity (K0.5 Ca2+ = 0.41 microM) suggesting the presence of a high affinity Ca2(+)-transporting ATPase. Calmodulin did not stimulate rat heart sarcoplasmic reticulum ATPase activity over a range of Ca2+ and Mg2+ concentrations and failed to stimulate membrane phosphorylation and Ca2+ transport into sarcoplasmic reticulum vesicles. Calmodulin antagonists trifluoperazine and compound 48/80 did not affect the ATPase activity. Catalytic subunit of cAMP-dependent protein kinase was also ineffective in stimulating the ATPase activity. These results suggest the presence of an ATPase activity in rat heart sarcoplasmic reticulum with different properties from the high affinity Ca2(+)-pumping ATPase previously characterized in dog heart and other species.

Animals↗
PubMed1990

Improved resolution of the initial fast phase of heavy sarcoplasmic reticulum Ca2+ uptake by Ca2+:antipyrylazo III dual-wavelength spectroscopy.

The effect of ATP upon difference absorbance due to Ca2+ and Mg2+ complexation with the metallochromic dye, Antipyrylazo III (AP III), was investigated. At divalent cation concentrations appropriate for Sarcoplasmic Reticulum Ca2+ transport, wavelengths (greater than 670 nm) were found whereupon the addition of up to 1mM nucleotide did not alter divalent cation:AP III difference absorbance. At these sample wavelengths an initial rapid uptake of Ca2+ by Heavy SR (HSR) was clearly resolved by dual wavelength spectroscopy of Ca2+:dye difference absorbance. Elimination of ATP interference of Ca2+:AP III absorbance by Mg2+ elevation (3-10mM) was shown to be an inappropriate general strategy for AP III spectroscopic studies of HSR Ca2+ transport due to Mg2+ inhibition of ryanodine receptor mediated Ca2+ release.

Adenosine Triphosphate↗
PubMed1990

Thoraco-abdominal enteric duplication with meningocele, skeletal anomalies and dextrocardia.

We describe an infant with an enteric thoraco-abdominal duplication arising in the proximal jejunum and associated with a dorsal meningocele, dextrocardia, agenesis of ribs and hypoplasia of the left arm. Diagnosis was reached post-operatively and the infant died of cytomegalovirus pneumonitis. Results of the postmortem examination are presented. Awareness of this rare malformation is required in order to reach a timely diagnosis and to plan a suitable operative approach.

Abnormalities, Multiple↗
PubMed1990

Acetaminophen hepatotoxicity: is there a role for prostaglandin synthesis?

The hepatotoxicity of acetaminophen (APAP) overdose depends on metabolic activation to a toxic reactive metabolite via hepatic mixed function oxidase. In vitro studies have indicated that APAP may also be cooxidized by prostaglandin H synthetase. The present experiments were designed to assess the possible contribution of hepatic prostaglandin synthesis to APAP toxicity. Adult fed male mice were overdosed with 400 mg APAP/kg. Liver toxicity was estimated by measurement of serum transaminases. Hypertonic xylitol or sodium chloride (2250 mOsm/l), administered intragastrically to stimulate prostaglandin synthesis, increased APAP toxicity. By contrast, the cyclooxygenase inhibiting drugs aspirin (at 25 mg/kg) and indomethacin (at 10 mg/kg) protected against APAP-induced toxicity. APAP kinetics were not affected by hypertonic xylitol or indomethacin, nor were hepatic glutathione levels in overdosed mice. Imidazole, a nonspecific thromboxane synthetase inhibitor, also protected overdosed mice. This drug prolonged hexobarbital sleeping time and prevented the depletion of hepatic glutathione that followed APAP intoxication. Thus, the data support the conclusion that APAP-induced hepatoxicity may be modulated not only by inhibition of cytochrome P450 mediated oxidation, but also by controlling hepatic cyclooxygenase activity.

Acetaminophen↗
PubMed1990

Familial Hirschsprung's disease--a report of 22 affected siblings in four families.

Twenty-two infants, belonging to four families from Gaza, presenting with typical features of Hirschsprung's disease are reported. Eight patients died at home shortly after birth, prior to 1974, due to low intestinal obstruction. Fourteen patients were referred to Hadassah University Hospital after 1974 and diagnosed, by rectal biopsy, as having Hirschsprung's disease. Thirteen underwent laparotomy and multiple intestinal biopsies. Ten had total intestinal aganglionosis, two had total or near total aganglionosis, and in only one patient was the common rectosigmoid aganglionosis found. One patient died prior to surgery. This unusual familial disease, involving very long aganglionic segments, raises the possibility that these infants suffered from a unique variant of Hirschsprung's disease.

Family↗
PubMed1990

Omega-3 fatty acid treatment fails to alter alpha 1-adrenergic receptor mediated phosphoinositide turnover in streptozotocin-induced diabetic rats.

1. The effect of omega-3 fatty acid supplementation on alpha 1-adrenergic receptor-mediated phosphoinositide turnover in the hearts of 6-week streptozotocin diabetic rats was studied. 2. The diabetic state was characterized by decreased body weight gain, hypoinsulinemia and hyperglycemia. Omega-3 fatty acid treatment did not have any significant effects on the above parameters. 3. Plasma triglyceride and cholesterol levels were significantly higher in diabetic rats compared with controls. 4. Omega-3 fatty acid treatment reduced the plasma triglyceride levels in the diabetic rats, whereas plasma cholesterol levels remained unaffected. 5. Norepinephrine (10 and 100 microM) stimulated inositol monophosphate (IP1) formation was significantly decreased in the diabetic rat heart compared with controls. Omega-3 fatty acid treatment had no significant effect on the norepinephrine-mediated IP1 formation in these rats. 6. Inositol bisphosphate (IP2) formation in response to 100 microM of norepinephrine was significantly lower in the diabetic rat heart; which was also not affected by omega-3 fatty acid treatment.

Animals↗
PubMed1990

Designing the national resident assessment instrument for nursing homes.

In response to the Omnibus Reconciliation Act of 1987 mandate for the development of a national resident assessment system for nursing facilities, a consortium of professionals developed the first major component of this system, the Minimum Data Set (MDS) for Resident Assessment and Care Screening. A two-state field trial tested the reliability of individual assessment items, the overall performance of the instrument, and the time involved in its application. The trial demonstrated reasonable reliability for 55% of the items and pinpointed redundancy of items and initial design of scales. On the basis of these analyses and clinical input, 40% of the original items were kept, 20% dropped, and 40% altered. The MDS provides a structure and language in which to understand long-term care, design care plans, evaluate quality, and describe the nursing facility population for planning and policy efforts.

Centers for Medicare and Medicaid Services, U.S.↗
PubMed1990

Genetic analysis of anthropometric measures in 11-year-old twins: the Medical College of Virginia Twin Study.

We have conducted a cross-sectional analysis of the genetic and environmental contributions to the variance of anthropometric measurements in children during early adolescence. Univariate path analysis was used to estimate the relative contributions of genes, individual environment, and family environment to measures of childhood obesity in 259 11-y-old Caucasian twin pairs. Triceps, subcapular, and suprailiac skinfold thicknesses, as well as waist circumferences, ht, and wt were measured in a standardized protocol. In this sample, a parsimonious model that included only additive genetic effects and environmental factors unique to the individual provided an adequate explanation for the variation in ht, wt, quetelet index, and subscapular and triceps skinfolds. In this largely preadolescent population, different magnitudes of genetic effects were seen in males and females for waist circumference, biiliac diameter, and suprailiac skinfold.

Anthropometry↗