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Biomedical subjects

S Katz

Publications and source records attributed to S Katz.

At least 73 records · Page 4Linked to original sources
PubMed1999

Pancreatitis associated with Crohn's disease: a premalignant state for cystadenocarcinoma of pancreas?

We report a 74-yr-old woman with Crohn's disease and acute pancreatitis who, 3 yr after resolution of the latter, developed cystadenocarcinoma of the pancreas. No drug, toxin, or other etiologies including contiguous duodenal involvement were identified as responsible for the pancreatitis, suggesting that pancreatitis was an extraintestinal manifestation of her Crohn's disease. Could Crohn's-associated pancreatitis be a premalignant state for cystadenocarcinoma of the pancreas?

Acute Disease↗
PubMed1999

Update in medical therapy in inflammatory bowel disease: a clinician's view.

Recent advances in the therapy of inflammatory bowel disease specifically directed against the inflammatory and immune mechanisms include an impressive and often overwhelming cornucopia of anti-inflammatory agents, immunomodulators, antibiotics, biologicals, topical therapies, nicotine, heparin, and nutritional supplements. The interface of one drug regimen into another may lead to confounding and often confusing programs of treatment. This review will attempt to offer a perspective of care and an update of specific remedies, but the aim is practicality and usefulness, not encyclopedic detail.

Adjuvants, Immunologic↗
PubMed1999

Tonsillectomy and adenotomy as a one day procedure?

With special reference to the postoperative hemorrhage rate and its subsequent course, we retrospectively evaluated the outcome of 2,363 tonsillectomies and 3,295 adenotomies performed over the last 11 years at our department. The postadenotomy major bleeding frequency was 0.2%. After tonsillectomy the immediate postoperative major bleeding frequency was 2.6% and 3.0%, respectively in children and adults. Secondary bleeding after tonsillectomy occurred in 0.3% of the children and 0.5% of the adults. In contrast to adenotomy, which can be considered as a safe one day procedure, based on our results we propose to perform tonsillectomy as a more prolonged, one night stay procedure.

Adenoids↗
PubMed1999

Ischemia induced activation of heat shock protein 27 kinases and casein kinase 2 in the preconditioned rabbit heart.

Protein kinase C (PKC), p38 MAP kinase, and mitogen-activated protein kinase-activated kinases 2 and 3 (MAPKAPK2 and MAPKAPK3) have been implicated in ischemic preconditioning (PC) of the heart to reduce damage following a myocardial infarct. This study examined whether extracellular signal-regulated kinase (Erk) 1, p70 ribosomal S6 kinase (p70 S6K), casein kinase 2 (CK2), and other hsp27 kinases are also activated by PC, and if they are required for protection in rabbit hearts. CK2 and hsp27 kinase activities declined during global ischemia in control hearts, whereas PC with 5 min ischemia and 10 min reperfusion increased their activities during global ischemia. Resource Q chromatography resolved two distinct peaks of hsp27 phosphotransferase activities; the first peak (at 0.36 M NaCl) appeared to correspond to the 55-kDa MAPKAPK2. Erk1 activity was elevated in both control and PC hearts after post-ischemic reperfusion, but no change was observed in p70 S6K activity. Infarct size (measured by triphenyltetrazolium staining) in isolated rabbit hearts subjected to 30 min regional ischemia and 2 h reperfusion was 31.0+/-2.6% of the risk zone in controls and was 10.3+/-2.2% in PC hearts (p<0.001). Neither the CK2 inhibitor 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole (DRB) nor the Mek1/2 inhibitor PD98059 infused during ischemia blocked protection by PC. The activation of CK2 and Erk1 in ischemic preconditioned hearts appear to be epiphenomena and not required for the reduction of infarction from myocardial ischemia.

Animals↗
PubMed1999

[Symptom severity among chronic schizophrenics in hospital and in the community].

We compared severity of symptoms of chronic schizophrenics in a psychiatric hospital with those treated in its outpatient clinics. The Positive and Negative Syndrome Scale and the Mini-Mental State examination were used to assess the schizophrenic symptoms and cognitive performance, respectively, of 25 chronic schizophrenic inpatients matched for gender, age and education with 25 chronic schizophrenic outpatients. The Global Assessment Scale and the Clinical Global Impression Scale were used to test global functioning. Assessment included psychiatric and medical history and treatment and demographic characteristics. In-patients had significantly more positive, negative and general psychiatric symptoms. Their cognitive and general functioning were impaired. Most in-patients also had medical problems. Age of onset of schizophrenia among the in-patients was younger. Results show a marked difference in severity of symptoms and level of functioning between chronic schizophrenic in-patients and out-patients. These differences should be considered in the planning of discharge of chronic in-patients from psychiatric hospitals into the community.

Humans↗
PubMed1998

Comparison between enzyme-linked immunosorbent assay and cytotoxic cross-match procedures for detecting IgG anti-donor antibodies.

BACKGROUND: Disadvantages inherent to complement-dependent cytotoxicity cross-match (CDC XM) methods are the requirements for complement and viable target cells, detection of antibodies (Abs) against non-HLA antigens, and subjective scoring. Cross-Stat (SangStat Medical Corp., Menlo Park, CA), a recently developed enzyme-linked immunosorbent assay XM procedure for the detection of IgG anti-donor HLA Abs, is theoretically devoid of these flaws. METHODS: We compared results of Cross-Stat and our standard anti-human globulin (AHG)-enhanced CDC XM procedure on 524 sera from 230 transplant candidates, which were evaluated against 51 cadaveric donors. RESULTS: There was a significant correlation between AHG-CDC IgG XM and Cross-Stat results (P<0.001). For false negative sera, repeat AHG-CDC IgG XMs were still positive after platelet absorption, indicating that the Abs present were either non-HLA Abs or anti-HLA class II. Flow cytometry testing of false positive sera usually (42/62) substantiated Cross-Stat results, indicating that the discrepancy with AHG-CDC IgG XM is caused by greater sensitivity of Cross-Stat. Relative to the AHG-CDC XM, the sensitivity of Cross-Stat was 100%, the specificity was 93%, the positive predictive value was 73%, and the negative predictive value was 100%. A technical shortcoming of the Cross-Stat assay is that the frequency of indeterminate samples in the assays was 15%. Among 49 Cross-Stat negative vs. 13 Cross-Stat positive primary cadaveric renal allograft recipients (all AHG-CDC IgG-XM negative), there was no statistical difference in overall graft survival. CONCLUSION: Given the important theoretical advantages of enzyme-linked immunosorbent assay-based XM methods over the CDC XM, however, further testing of the clinical relevance of the Cross-Stat is warranted.

Enzyme-Linked Immunosorbent Assay↗
PubMed1998

Can an immunologically, nonreactive potential allograft recipient undergo transplantation without a donor-specific crossmatch?

Performance of the pretransplant crossmatch requires 4 or more hours . Delays in the crossmatch might alter operating room availability and thereby increase donor organ cold ischemia time that might then result in increased risk of delayed graft function. To avoid these problems, recipients could be identified who would be expected to display negative donor crossmatches and who could be transplanted with a concurrent or retrospective rather than a pretransplant crossmatch. We, therefore, evaluated the percent reactive antibodies and donor IgG-antihuman globulin (AHG) crossmatch results of 1165 sera from 220 potential allograft recipients. Twenty-five (11%) of 220 recipients consistently displayed a 0% PRA and, with only one exception, their sera (n= 156) tested IgG-AHG crossmatch-negative against potential cadaveric donors (a 0.6% IgG-AHG positive crossmatch risk). These data suggest that the timing of the pretransplant serum crossmatch could be altered for a highly selected group of immunologically nonreactive recipients.

Female↗
PubMed1998

[Bowel-lengthening in a newborn with short bowel syndrome].

Advances in parenteral nutrition and supportive therapy have led to improvement in survival of babies with short-bowel syndrome. Those whose intestinal mass is very unlikely to be adequate should have surgical therapy as soon as possible, before they develop the complications of long-term parenteral nutrition or significant enteritis. We present a newborn with short-bowel syndrome due to prenatal midgut volvulus. At operation the remaining viable jejunum, 15 cm long, was anastomosed to the cecum. All feeding attempts failed, and the infant suffered from malabsorption. Calories and proteins had to be supplied by intravenous total parenteral nutrition. At 3 months of age there was significant widening of the remaining bowel and Bianchi's bowel-lengthening procedure was performed. The postoperative course was uneventful and there was gradual improvement in intestinal absorptive capacity. The patient was weaned from parenteral nutrition at 3 years of age. Now, 2 years later, she eats a normal diet.

Anastomosis, Surgical↗
PubMed1998

Insulin-regulated protein kinases during postnatal development of rat heart.

The control of glucose uptake and glycogen metabolism by insulin in target organs is in part mediated through the regulation of protein-serine/threonine kinases. In this study, the expression and phosphotransferase activity levels of some of these kinases in rat heart ventricle were measured to investigate whether they might mediate the shift in the energy dependency of the developing heart from glycogen to fatty acids. Following tail-vein injection of overnight fasted adult rats with 2 U of insulin per kg body weight, protein kinase B (PKB), the 70-kDa ribosomal S6 kinase (S6K), and casein kinase 2 (CK2) were activated (30-600%), whereas the MAP/extracellular regulated kinases (ERK)1 and ERK2 were not stimulated under these conditions. When the expression levels of the insulin-activated kinases were probed with specific antibodies in ventricular extracts from 1-, 10-, 20-, 50-, and 365-day-old rats, phosphatidylinositol 3-kinase (PI3K), PKB, S6K, and CK2 were downregulated (40-60%) with age. By contrast, ventricular glycogen synthase kinase-3beta (GSK3beta) protein levels were maintained during postnatal development. Similar findings were obtained when the expression of these kinases was investigated in freshly isolated ventricular myocytes, where they were detected predominantly in the cytosolic fraction of the myocytes. Compared to other adult rat tissues such as brain and liver, the levels of PI3K, PKB, S6K, and GSK3beta were relatively low in the heart. Even though CK2 protein and activity levels were reduced by approximately 60% in 365 day as compared to 1-day-old rats, expression of CK2 in the adult heart was as high as detected in any of the other rat tissues. The high basal activities of CK2 in early neonatal heart may be associated with the proliferating state of myocytes.

Amino Acid Sequence↗
PubMed1998

Expression of mitogen-activated protein kinase pathways during postnatal development of rat heart.

The loss of ability to proliferate (terminal differentiation) and reduction in capability to resist ischemia are key phenomena observed during postnatal development of the heart. Mitogen-activated protein kinases (MAPKs) mediate signaling pathways for cell proliferation/differentiation and stress responses such as ischemia. In this study, the expression of these kinases and their associated kinases were investigated in rat heart ventricle. Extracts of 1-, 10-, 20-, 50-, and 365-day-old rat heart ventricles were probed with specific antibodies and their immunoreactivities were quantified by densitometry. Most of the mitogenic protein kinases including Raf1, RafB, Mek1, Erk2, and Rsk1 were significantly down-regulated, whereas the stress signaling kinases, such as Mlk3, Mekkl, Sekl, Mkk3, and Mapkapk2 were up-regulated in expression during postnatal development. Most MAP kinases including Erk1, JNKs, p38 Hog, as well as Rsk2, however, did not exhibit postnatal changes in expression. The proto-oncogene-encoded kinases Mos and Cot/Tpl 2 were up-regulated up to two- and four-fold, respectively, during development. Pakl, which may be involved in the regulation of cytoskeleton as well as in stress signaling, was downregulated with age, but the Pak2 isoform increased only after 50 days. All of these proteins, except RafB, were also detected in the isolated adult ventricular myocytes at comparable levels to those found in adult ventricle. Tissue distribution studies revealed that most of the protein kinases that were up-regulated during heart development tended to be preferentially expressed in heart, whereas the downregulated protein kinases were generally expressed in heart at relatively lesser amounts than in most of other tissues.

Amino Acid Sequence↗
PubMed1998

The ras recruitment system, a novel approach to the study of protein-protein interactions.

The yeast two-hybrid system represents one of the most efficient approaches currently available for identifying and characterizing protein-protein interactions [1-4]. Although very powerful, this procedure exhibits several problems and inherent limitations [5]. A new system, the Sos recruitment system (SRS), was developed recently [6] based on a different readout from that of the two-hybrid system [6-8]. SRS overcomes several of the limitations of the two-hybrid system and thus serves as an attractive alternative for studying protein-protein interactions between known and novel proteins. Nevertheless, we encountered a number of problems using SRS and so have developed an improved protein recruitment system, designated the Ras recruitment system (RRS), based on the absolute requirement that Ras be localized to the plasma membrane for its function [9-10]. Ras membrane localization and activation can be achieved through interaction between two hybrid proteins. We have demonstrated the effectiveness of the novel RRS system using five different known protein-protein interactions and have identified two previously unknown protein-protein interactions through a library screening protocol. The first interaction (detailed here) is between JDP2, a member of the basic leucine zipper (bZIP) family, and C/EBPgamma, a member of the CCAAT/enhancer-binding protein (C/EBP) family. The second interaction is between the p21-activated protein kinase Pak65 and a small G protein (described in the accompanying paper by Aronheim et al. [11]). The RRS system significantly extends the usefulness of the previously described SRS system and overcomes several of its limitations.

CCAAT-Enhancer-Binding Proteins↗
PubMed1998

Randomized, placebo-controlled trial of platelet glycoprotein IIb/IIIa blockade with primary angioplasty for acute myocardial infarction. ReoPro and Primary PTCA Organization and Randomized Trial (RAPPORT) Investigators.

BACKGROUND: The benefit of catheter-based reperfusion for acute myocardial infarction (MI) is limited by a 5% to 15% incidence of in-hospital major ischemic events, usually caused by infarct artery reocclusion, and a 20% to 40% need for repeat percutaneous or surgical revascularization. Platelets play a key role in the process of early infarct artery reocclusion, but inhibition of aggregation via the glycoprotein IIb/IIIa receptor has not been prospectively evaluated in the setting of acute MI. METHODS AND RESULTS: Patients with acute MI of <12 hours' duration were randomized, on a double-blind basis, to placebo or abciximab if they were deemed candidates for primary PTCA. The primary efficacy end point was death, reinfarction, or any (urgent or elective) target vessel revascularization (TVR) at 6 months by intention-to-treat (ITT) analysis. Other key prespecified end points were early (7 and 30 days) death, reinfarction, or urgent TVR. The baseline clinical and angiographic variables of the 483 (242 placebo and 241 abciximab) patients were balanced. There was no difference in the incidence of the primary 6-month end point (ITT analysis) in the 2 groups (28.1% and 28.2%, P=0.97, of the placebo and abciximab patients, respectively). However, abciximab significantly reduced the incidence of death, reinfarction, or urgent TVR at all time points assessed (9.9% versus 3.3%, P=0.003, at 7 days; 11.2% versus 5.8%, P=0.03, at 30 days; and 17.8% versus 11.6%, P=0.05, at 6 months). Analysis by actual treatment with PTCA and study drug demonstrated a considerable effect of abciximab with respect to death or reinfarction: 4.7% versus 1.4%, P=0.047, at 7 days; 5.8% versus 3.2%, P=0.20, at 30 days; and 12.0% versus 6.9%, P=0.07, at 6 months. The need for unplanned, "bail-out" stenting was reduced by 42% in the abciximab group (20.4% versus 11.9%, P=0.008). Major bleeding occurred significantly more frequently in the abciximab group (16.6% versus 9.5%, P=0.02), mostly at the arterial access site. There was no intracranial hemorrhage in either group. CONCLUSIONS: Aggressive platelet inhibition with abciximab during primary PTCA for acute MI yielded a substantial reduction in the acute (30-day) phase for death, reinfarction, and urgent target vessel revascularization. However, the bleeding rates were excessive, and the 6-month primary end point, which included elective revascularization, was not favorably affected.

Abciximab↗
PubMed1998

Expression of second messenger- and cyclin-dependent protein kinases during postnatal development of rat heart.

During early postnatal development, cardiomyocytes, which comprise about 80% of ventricular mass and volume, become phenotypically developed to facilitate their contractile functions and terminally differentiated to grow only in size but not in cell number. These changes are due to the expression of contractile proteins as well as the regulation of intracellular signal transduction proteins. In this study, the expression patterns of several protein kinases involved in various cardiac functions and cell-cycle control were analyzed by Western blotting of ventricular extracts from 1-, 10-, 20-, 50-, and 365-day-old rats. The expression level of cAMP-dependent protein kinase was slightly decreased (20%) over the first year, whereas no change was detected in cGMP-dependent protein kinase I. Calmodulin-dependent protein kinase II, which is involved in Ca2+ uptake into the sarcoplasmic reticulum, was increased as much as ten-fold. To the contrary, the expressions of protein kinase C-alpha and iota declined 77% with age. Cyclin-dependent protein kinases (CDKs) such as CDK1, CDK2, CDK4, and CDK5, which are required for cell-cycle progression, abruptly declined to almost undetectable levels after 10-20 days of age. In contrast, other CDK-related kinases, such as CDK8 or Kkialre, did not change significantly or increased up to 50% with age, respectively. Protein kinases implicated in CDK regulation such as CDK7 and Wee1 were either slightly increased in expression or did not change significantly. All of the proteins that were detected in ventricular extracts were also identified in isolated cardiac myocytes in equivalent amounts and analyzed for their relative expression in ten other adult rat tissues.

Aging↗
PubMed1998

[Enhancing cultural sensitivity of psychiatrists emigrating from Russia to Israel].

The importance of understanding the local culture and enhancing cultural sensitivity became evident during supervision of immigrant psychiatrists from the former Soviet Union. The aim of the present study was to describe enhancement of this cultural sensitivity in the supervision of 2 immigrant psychiatrists. In the first, understanding the patient's cultural world helped the immigrant psychiatrist form the therapeutic alliance. In the second, the immigrant psychiatrist's understanding of the patient's cultural background led him to change both diagnosis and treatment. In both cases, development of cultural sensitivity through supervision enabled successful treatment. Enhancement of cultural sensitivity may accelerate absorption of the immigrant psychiatrists themselves. Discussing cultural issues during work may accelerate the absorption of all immigrant physicians.

Adult↗
PubMed1998

Congenital short-bowel syndrome: prenatal sonographic findings of a fatal anomaly.

The sonographic findings in a fatal case of congenital short-bowel syndrome are reported. Sonography at 11 weeks of gestation showed a 11 x 6 mm hyperechoic mass interpreted to be a midgut umbilical hernia. A repeat scan 2 weeks later showed an intact anterior abdominal wall, no umbilical herniation, and appropriate fetal growth. Forty-eight hours after full-term, vaginal delivery, the infant began vomiting bile and passing blood rectally. Imaging studies showed distended bowel loops without air-fluid levels and incomplete bowel obstruction. Laparotomy showed malrotation and short small bowel without volvulus. The infant died at 9 weeks of age. When delayed return of the midgut to the abdominal cavity is noted on prenatal sonograms, follow-up sonograms should be done throughout the second trimester, especially in patients with a family history of short-bowel syndrome, to search for dilated short bowel loops. If such loops are found, patients should be given options for pregnancy termination.

Fatal Outcome↗
PubMed1998

Idiopathic non-obstructive hypertrophic cardiomyopathy, vitamin B12 deficiency and gastric adenocarcinoma: an unreported association in a teenager.

UNLABELLED: A 14-year-old boy presented with anorexia and weakness whereon the diagnosis of dimorphic anaemia was made. An excellent response to iron and vitamin B12 was observed. In addition, the patient had non-obstructive hypertrophic cardiomyopathy. At endoscopy 2.5 years later, an adenocarcinoma was diagnosed and the patient underwent a high subtotal gastrectomy. To the best of our knowledge, this rare association has never been reported in children. CONCLUSION: We report a youngster with pernicious anaemia, associated with nonobstructive hypertrophic cardiomyopathy in whom gastric adenocarcinoma was found. Patients with pernicious anaemia are at greater risk of developing gastric carcinoma than the general population, therefore we recommend routine periodic gastroscopic surveillance in the paediatric population with pernicious anaemia.

Adenocarcinoma↗