Search PubMed⌕ Search

Biomedical subjects

S Katz

Publications and source records attributed to S Katz.

At least 289 records · Page 16Linked to original sources
PubMed1986

Babies born with AIDS.

Explore the source record for details and available documents.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Fluorometric determination of nanogram quantities of protein in small samples: application to calcium-transport adenosine triphosphatase.

A fluorometric micro protein assay based on fluorescamine-labelling of homogeneous proteins in solution has been developed which is capable of accurately quantitating as little as 25 ng protein at a concentration of 1.25 micrograms/ml. This micro assay uses a flow-through HPLC fluorescence detector. Typical micro assays measuring bovine serum albumin standards (0-25 mg/l) yielded linear regression coefficients of r = 0.999. Assays of purified Ca2+-ATPase solutions determined by the micro fluorescamine procedure correlated well with measurements made using the deoxycholate-TCA-precipitation modification of the Lowry assay: 1.0 microgram ATPase by Lowry method = 1.1 microgram protein by fluorescamine microassay (when both procedures were standardized with bovine serum albumin) (r = 0.995). The assay proposed offers a 100-fold increase in sensitivity, compared to the Lowry procedure.

Calcium-Transporting ATPases↗
PubMed1986

Semipermeable occlusive dressings. Effects on growth of pathogenic bacteria and reepithelialization of superficial wounds.

Six commercially available semiocclusive dressings were tested for their effect on the growth of resident and pathogenic bacteria and the reepithelialization of experimentally induced wounds in human volunteers. Scarification and abrasion-type wounds inoculated with Staphylococcus epidermidis, Staphylococcus aureus, Streptococcus pyogenes, and Pseudomonas aeruginosa were quantitatively cultured at different times after being covered with the dressings. Reepithelialization was assessed by serial stereomicrographs. None of the dressings was able to prevent clinical infection. All dressings provided microenvironments that were conducive to the growth of resident and pathogenic bacteria. There was no difference in the rates of reepithelialization.

Adult↗
PubMed1986

Varicocele in children: "to treat or not to treat"--venographic and manometric studies.

The management of varicocele is still controversial in spite of its high incidence (15%) in prepubertal boys and young adults and although it is believed to represent a major contributing factor to male subfertility. Fifty boys between 6 and 14 years of age were operated on for left varicocele, and a long segment of the left internal spermatic vein was excised. Thirty-four of them underwent preoperative retrograde left renal venography and pressure readings in both renal veins and inferior vena cava. In all 50 patients, intraoperative antegrade (via internal spermatic vein) left renal venography was performed. This examination revealed impaired renal venous drainage in 38 patients (group A) and normal venous return through the left renal vein in 12 patients (group B). In all 34 patients (from both groups) on whom retrograde venography was performed, there was marked renospermatic reflux. The pressure readings in the left renal vein were significantly increased in group A only. Our data strongly suggest that left varicocele is caused by renospermatic venous reflux and that this condition is probably irreversible. The reflux in group A is explained by the impaired venous drainage through the left renal vein. In group B, it is our impression that the reflux is a result of a congenitally valveless left internal spermatic vein. If varicocele is indeed a major cause for infertility, then our data logically point toward surgery.

Adolescent↗
PubMed1986

Methylmethacrylate upper ureteral obstruction.

A case of upper ureteral obstruction caused by methylmethacrylate cement after fixation of an L2-L3 vertebral fracture is reported. The probable mechanism, radiographic findings, and management of this complication are reviewed.

Female↗
PubMed1986

Investigation of (Ca2+ + Mg2+)-ATPase phosphoprotein formation in erythrocyte membranes of patients with cystic fibrosis.

The (Ca2+ + Mg2+)-ATPase present per mg of protein in erythrocyte membranes of controls and patients with cystic fibrosis (CF) was determined by estimation of the levels of its phosphoprotein. In the presence of 10 mM free Ca2+, which inhibits phosphoprotein decomposition, significantly less phosphoprotein intermediate, ECaP, was found in erythrocyte membranes from CF patients than in age- and sex-matched controls; this correlated with a significant decrease in (Ca2+ + Mg2+)-ATPase activity. These observations indicate a decrease in the number of functional (Ca2+ + Mg2+)-ATPase molecules in erythrocyte membranes from CF patients or an alteration in either the structure of the pump protein or the composition of its environment.

Ca(2+) Mg(2+)-ATPase↗
PubMed1986

Non-iatrogenic deep vein thrombosis of lower extremities in children.

Non-iatrogenic ileo-femoral vein thrombosis is rarely encountered in childhood. Six children with postphlebitic leg following venous thrombosis are presented. Venous thrombosis occurred following peritonitis, osteomyelitis and scarlet fever. None of the patients had history of trauma or intravenous treatment. Based on world literature and our experience, the main clinical and radiological manifestations of this rare entity are summarised. Early detection and aggressive anti-coagulant therapy of deep vein thrombosis may probably prevent post-thrombotic syndrome--a major disabling condition in children.

Adolescent↗
PubMed1986

Treatment of colorectal hepatic metastases by intrahepatic chemotherapy alone or as an adjuvant to complete or partial removal of metastatic disease.

Because of the wide variation in reported benefits from the use of intrahepatic chemotherapy for colorectal hepatic metastases, the authors performed their own phase II studies comparing the use of intrahepatic chemotherapy alone and intrahepatic chemotherapy as an adjuvant to complete or partial removal of metastatic colorectal cancer to the liver. Techniques for partial removal included unilateral and bilateral wedge resection, peripheral presinusoidal embolization of the liver, and portal vein branch ligation. Patients were staged using the per cent hepatic replacement method of Pettavel and Taylor, and patients with bilateral metastases were included in the study. Twenty-seven patients, mean age 60.3 years, were examined. There were 19 males, mean age 60.4 years, and eight females, mean age 60 years. The patients were divided into four groups. Group A had an implantable pump only; Group B had an implantable pump and resection; Group C had an implantable pump and arterial embolization and portal vein branch ligation; and Group D had an implantable pump, partial resection, arterial embolization, and portal vein branch ligation. Kaplan-Meyer survival curves were calculated for all of these groups. A separate analysis was carried out for each of the stages, and a comparison was made. The study indicated that the overall median survival time was 18 months and that the more radical the treatment in addition to chemotherapy, the better the results. Such results were not totally dependent on the staging of the tumor volume but were dependent on the degree of extirpation of the tumor. In Group C, consisting primarily of Stage IIa, IIIa, and IV patients (i.e., unresectable patients), a doubling of expected median survival to 12 months could be achieved, compared to those in Group A, which achieved a median survival of only 6 months.

Adult↗
PubMed1986

Thyroidectomy of SHR: effects on ventricular relaxation and on SR calcium uptake activity.

Ventricular hypertrophy and hypothyroidism are each characterized by impaired cardiac muscle relaxation and sarcoplasmic reticulum (SR) calcium uptake activity. A previous report also showed that hypothyroidism does not reverse ventricular hypertrophy (left-to-right ventricular weight ratios) of spontaneously hypertensive rats (SHR). We characterized the effects of thyroidectomy of 8 wk duration on relaxation of ejecting hearts and on SR calcium uptake activity from SHR and nonhypertrophic Wistar-Kyoto rat (WKY) controls. Relaxation was quantified by plotting maximum left ventricular pulse pressure (Pmax) vs. the area under the falling phase of the left ventricular pressure wave at three different pressure loads. Ventricles of euthyroid SHR were characterized by impaired relaxation and depressed SR calcium uptake activity compared with those of euthyroid WKY, confirming earlier studies. Thyroidectomy reduced ventricular relaxation and SR calcium uptake activities to about the same extent in SHR and WKY strains so that these measurements were most depressed in the SHR hypothyroid group. When all groups were considered, the extent of mechanical relaxation ex vivo and the rate of SR calcium uptake in vitro were well correlated.

Animals↗
PubMed1986

Isolation and characterization of erythrocyte membrane Ca2+-ATPase in cystic fibrosis.

Ca2+-ATPase was purified from erythrocyte membranes prepared from cystic fibrosis (CF) blood samples (n = 10) and from age/sex-matched control blood samples (n = 10). The kinetics of calcium activation of the purified enzyme was investigated in the presence of asolectin phospholipids and found to be virtually identical for both CF and control preparations: VCa2+ = 3.01 +/- 0.24 mumol ATP hydrolyzed/mg pure enzyme/min (mean +/- SE) and 3.09 +/- 0.20 for CF and control Ca2+-ATPase, respectively; KCa2+ = 0.328 +/- 0.046 mu molar free calcium and 0.333 +/- 0.040 for CF and control enzyme, respectively. The preparative procedure used (one-step purification by calmodulin-affinity chromatography) allowed quantitative recovery of essentially 100% of the Ca2+-ATPase present in detergent-solubilized erythrocyte membranes, enabling expression of the yield of purified enzyme in terms of the quantity of starting membrane protein: 0.127% +/- 0.006% (w/w) and 0.140% +/- 0.007% for CF and control enzyme preparations, respectively. None of the parameters evaluated showed a statistically significant difference (p less than 0.05) between the CF and control groups. Furthermore, when CF and control purified Ca2+-ATPase samples were analyzed by high-resolution gradient SDS-polyacrylamide gel electrophoresis, no differences in mobility were observed (mol wt = 128 kdaltons). Thus, Ca2+-ATPase purified from CF erythrocyte membranes and assayed in the presence of asolectin appears to be quantitatively similar to control purified enzyme in amount, molecular weight, and kinetics of activation by calcium. These data suggest that Ca2+-ATPase may not be the defective gene product in CF.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗