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Biomedical subjects

S Katz

Publications and source records attributed to S Katz.

At least 37 records · Page 2Linked to original sources
PubMed2001

Abdominal injuries caused by bicycle handlebars.

OBJECTIVE: To find out whether the increase in the number of children admitted with injuries from mountain bicycle handlebars is attributed to recent changes in the design of children's bicycles. DESIGN: Retrospective study. SETTING: Teaching general hospital, Israel. SUBJECTS: 76 children who presented with abdominal injuries caused by bicycle handlebars. RESULTS: In 12 of the 76 children, there was an imprint of the handlebar edge on the hypochondrium. The most common injuries were isolated ruptures of spleen or liver, (14 and 11 patients, respectively). Five of the 25 patients were operated on and the rest treated conservatively. CONCLUSIONS: Children with an imprint or bruise made by the handlebar edge on the abdominal wall, or who give a clear history of injuries by a bicycle handlebar should be treated with great care. BMX handlebars are relatively high (for young riders) and wide; they also turn freely and are therefore in direct line with the upper abdomen. Prohibiting the use of bicycles with unpadded handlebars may prevent some of these intra-abdominal injuries.

Abdominal Injuries↗
PubMed2001

Pseudotumor of the bladder as a manifestation of uncomplicated appendicitis.

We report the case of a 67-year-old woman who presented with an apparent bladder tumor and complaints of increased urinary frequency and postvoiding pain. Her diagnostic work-up revealed conflicting findings regarding the source of her bladder disease, and laparoscopy was required to make the final diagnosis of appendicitis. The presentation of appendicitis can be disguised and is often a difficult diagnosis.

Aged↗
PubMed2001

The IBD1 locus for susceptibility to Crohn's disease has a greater impact in Ashkenazi Jews with early onset disease.

OBJECTIVE: Recent studies have suggested that a susceptibility gene located on chromosome 16 and designated IBD1 may contribute to the development of Crohn's disease (CD). However, these findings were observed in predominantly non-Jewish populations; in the three studies where Ashkenazi Jews were included for analysis, the results have been widely divergent. Because Ashkenazi Jews are known to have a higher incidence of the disease than non-Jews, we sought to determine whether this previously reported linkage could be extended to the Ashkenazi population. In addition, we examined whether Ashkenazi Jewish patients with an early age of onset (< or = 21 yr) showed greater evidence of linkage to this locus. METHODS: Linkage analysis for the IBD1 region was performed on 123 Ashkenazi Jewish CD patients distributed among 53 families. Only patients with four Jewish grandparents were considered to be Jewish. Of the 123 Ashkenazi Jewish patients, 75 (61%) had an age of onset < or = 21 yr. RESULTS: Ashkenazi Jews showed only modest evidence of linkage (nonparametric linkage 1.63, p = 0.05) to the IBD1 locus. However, when the Ashkenazi population was subdivided on the basis of age of onset, there was a striking increase in linkage in families where affected individuals had an age of onset < or = 21 yr (nonparametric linkage 3.02, p = 0.002). In contrast, there was no evidence of linkage in the Jewish families where all affected individuals had an age of onset > 21 yr. CONCLUSIONS: The IBD1 gene plays a greater role in conferring susceptibility to CD in Jews with early onset disease than in Jews with late onset disease.

Adult↗
PubMed2001

Psychological distress, social support, and disease activity in patients with inflammatory bowel disease.

OBJECTIVES: The objectives of this study were to compare the psychological status of patients in active and inactive disease states, to assess social support, and to identify correlates of psychological distress in patients with inflammatory bowel disease (IBD). METHODS: This cross-sectional study was conducted in 200 patients (mean age 36.7 yr [SD = 14.8], 119 [59.5%] female) with long-standing IBD who were seen in tertiary care. Psychosocial assessments included psychological distress (Symptom Checklist-90R), social support (Social Support Questionnaire-6), perceived stress (Perceived Stress Scale-10), and recent minor stressful events (Weekly Stress Inventory). Disease activity was assessed with the Harvey Bradshaw Index. RESULTS: Patients reported higher levels of satisfaction with social support and smaller network sizes compared with normative values. Using multiple linear regression, the independent correlates of psychological distress (p = 0.0001; adjusted R2 = 0.62) were as follows: active disease (p = 0.0234), less time since diagnosis (p = 0.0012), and greater number (p = 0.0001) and impact of stressful events (p = 0.0003). A statistically significant interaction term (p = 0.0171) revealed that the relationship between psychological distress and perceived stress changes depending on the level of satisfaction with social support. For patients with low levels of perceived stress, satisfaction with social support did not affect levels of psychological distress. However, for patients who experienced moderate to high levels of perceived stress, high satisfaction with social support decreased the level of psychological distress. CONCLUSIONS: These findings suggest that strategies aimed at improving social support can have a favorable impact on psychological distress and, ultimately, can improve health outcomes in patients with IBD.

Adult↗
PubMed2001

Kaposi's sarcoma and cytomegaloviral ileocolitis complicating long-standing Crohn's disease in an HIV-negative patient.

A 67-yr-old woman with a 25-yr history of Crohn's disease, maintained on near-continuous corticosteroids (prednisone 10 mg daily) over a 6-yr period, underwent ileocolic resection for obstruction. Pathology revealed Crohn's disease, multiple nodules of Kaposi's sarcoma, and cytomegalic inclusion bodies with confirmation of cytomegalovirus by shell vial immunofluorescence. Testing for HIV serum antibody has been repeatedly negative. Crohn's disease, Kaposi's sarcoma, and cytomegalovirus have been clinically in remission for 5 yr.

Aged↗
PubMed2001

AP-1 repressor protein JDP-2: inhibition of UV-mediated apoptosis through p53 down-regulation.

Members of the AP-1 transcription factor family, especially c-Jun and c-Fos, have long been known to mediate critical steps in the cellular response to ultraviolet (UV) irradiation. We sought to examine whether two newly discovered members of the AP-1 family, JDP-1 and JDP-2, also participate in the mammalian UV response. Here we report that JDP-2, but not JDP-1, is transiently induced upon UV challenge and that elevated levels of JDP-2 increase cell survival following UV exposure. This protective function of JDP-2 appears to be mediated through repression of p53 expression at the transcriptional level, via a conserved atypical AP-1 site in the p53 promoter.

3T3 Cells↗
PubMed2001

Intra-operative quality assessment of coronary artery bypass grafts.

Early coronary artery bypass graft (CABG) failure is a troubling complication that may result in a wide range of problems, including refractory angina, myocardial infarction, low cardiac output, arrhythmia, and fatal heart failure. Early graft failures are related to poor quality and size of the distal native vascular bed, coagulation abnormalities, or technical problems involving the graft conduits and anastomoses. Unfortunately, graft failure is difficult to detect during surgery by visual assessment, palpation, or conventional monitoring. We evaluated the accuracy and utility of a transit-time, ultrasonic flow measurement system for measurement of CABGs. There were no differences between transit-time measurements and volumetric-time collected samples in an in vitro circuit over a range of flows from 10 to 100ml/min (Bland and Altman Plot, 1.96 SD). Two hundred and ninety-eight CABGs were examined in 125 patients. Graft flow rate was proportional to the target vessel diameter. Nine technical errors were detected and corrected. Flow waveform morphology provided valuable information related to the quality of the anastamosis, which led to the immediate correction of technical problems at the time of surgery.

Anastomosis, Surgical↗
PubMed2001

Intermittent, luteal phase nefazodone treatment of premenstrual dysphoric disorder.

Three outpatients who fulfilled full DSM-IV diagnostic criteria for premenstrual dysphoric disorder (PDD) were successfully treated with intermittent (luteal phase) nefazodone. They received the medication at low doses of up to 100 mg/day (50 mg b.i.d.), for 2 weeks through the luteal phase of the menstrual cycle only. All the patients reported a marked symptomatic improvement, including full remission of their emotional symptoms, and two achieved in addition full remission of their somatic symptoms. Side-effects reported during the treatment were mild. The use of luteal phase nefazodone seems to be a promising treatment strategy for the management of PDD. It offers advantages over daily dosing throughout the menstrual cycle, such as reduced incidence and severity of side-effects, and avoids the stigma that may accompany the continuous use of psychopharmacological treatment, with the advantage that compliance may be improved.

Adult↗
PubMed2000

Initial results of solitary pancreas transplants performed without regard to donor/recipient HLA mismatching.

BACKGROUND: We hypothesized that solitary pancreas transplants could be performed successfully even in the presence of poor HLA matching if an aggressive approach were taken with regard to immunosuppressive protocol and the performance of allograft biopsy. METHODS: Seven pancreas-after-kidney transplants and seven pancreas transplants alone were performed without consideration given to the degree of HLA mismatching (MM) using tacrolimus (FK506)/mycophenolate mofetil (MMF)/prednisone maintenance therapy. Mean (+/-SD) total HLA MM was 4.8+/-1.2. All patients were followed for at least 6 months. The first four cases were induced with ATGAM for 7 to 10 days. In the remaining 10 cases, an ultrasound-guided percutaneous needle biopsy was attempted on a protocol basis 10 days after completing induction with OKT3 for 7 (n=2) or 14 (n=8) days. RESULTS: Overall patient survival, graft survival, and incidence of acute rejection requiring treatment were 86, 79, and 50%, respectively. Two patients receiving ATGAM developed grade III-IV rejection at 3 weeks. Both patients receiving OKT3 for 7 days developed early grade III rejection. However, only three of eight patients receiving OKT3 for 14 days developed rejection requiring treatment. Protocol biopsy was successfully performed in six of seven patients and uncovered three cases of otherwise undetectable grade III-IV rejection. CONCLUSIONS: Although based on a small number of cases, our results suggest that solitary pancreas transplants with a poor HLA match can be performed with an acceptable rejection incidence and graft survival rate using an OKT3/FK506/MMF/prednisone regimen with protocol biopsy.

Adolescent↗
PubMed2000

Ingested interferon-alpha prevents allograft islet transplant rejection.

BACKGROUND: Ingested interferon (IFN)-alpha is a biological response modifier in experimental autoimmune encephalomyelitis and multiple sclerosis, and prevents type 1 diabetes in nonobese diabetic mice. Islet transplantation possesses significant potential advantages over whole-gland transplantation because it is simple, may achieve insulin independence, and has clear advantages over exogenous insulin therapy. Therefore, we examined whether ingested IFN-alpha, administered to islet allograft recipients, could prevent islet allograft rejection. METHODS: Recipient C3H mice (H2k) were made diabetic and either untreated or treated with 10-1000 international units (IU) of ingested murine IFN-alpha daily from day -7 through day +14 after transplantation for a total of 21 days. Seven days after diabetes induction, recipients received allograft islets isolated from C57BL.10 donors (H2b) under the kidney capsule and were followed for overt diabetes via elevated blood glucose. RESULTS: Control recipients and recipients fed 1000 IU all became diabetic by day 13, whereas mice ingesting IFN-alpha had delayed rejection for up to 27 (10 IU) to 29 days (100 IU) after islet transplantation. Treatment of recipients of islet allografts with ingested IFN-alpha doubles the time period before rejection compared with control mice. The feeding period with daily IFN-alpha was doubled from 21 days to 42 days in total, 7 days before transplantation and 35 days after transplantation. CONCLUSION: Treatment of recipients of islet allografts with prolonged ingested IFN-alpha prevents rejection in a subset of recipients. Ingested IFN-alpha may prevent rejection if given continuously after transplantation.

Administration, Oral↗
PubMed2000

Stimulation of 90- and 70-kDa ribosomal protein S6 kinases by arginine vasopressin and lysophosphatidic acid in rat cardiomyocytes.

Arginine vasopressin (AVP) and lysophosphatidic acid (LPA) have been shown to stimulate protein kinase C (PKC) and mitogen-activated protein (MAP) kinases and the proliferation of vascular smooth muscle cells. However, the actions of these two agents in cardiomyocytes are less well understood. To investigate the signal transduction pathways of AVP and LPA, freshly isolated adult rat cardiomyocytes were examined. Both AVP and LPA induced concentration- and time-dependent stimulation of the phosphotransferase activities of p90 ribosomal S6 kinases (RSK) and their upstream activators, extracellularly regulated kinases (ERK) 1 and 2. The activation of ERK1 and ERK2 by LPA was PKC- and phosphatidylinositol 3-kinase (PI 3-kinase)-dependent. However, AVP-induced activation of RSK2, a downstream substrate of ERK1 and ERK2, was PKC-dependent and PI 3-kinase-independent. AVP and LPA were also observed to increase the phosphotransferase activity of p70 ribosomal protein S6 kinase (p70 S6K) in a time- and concentration-dependent manner. The activation of p70 S6K by LPA and AVP was PI 3-kinase-dependent. PKC was necessary in AVP- but not in LPA-induced activation of p70 S6K. Since RSK and p70 S6K have been implicated in the regulation of translational control of protein synthesis, we concluded that AVP and LPA may stimulate the growth of cardiomyocytes through these two protein kinase cascades.

Animals↗
PubMed2000

Cyclic GMP-dependent and -independent regulation of MAP kinases by sodium nitroprusside in isolated cardiomyocytes.

Sodium nitroprusside (SNP) elicits various physiological effects, in part through generation of the membrane permeable mediator nitric oxide (NO). In the heart, besides its role in regulating contractility, NO is involved in both protection from and induction of cellular damage. The present study investigated the role of SNP in the regulation of the mitogen-activated protein kinases (MAPKs) in isolated adult rat cardiomyocytes. SNP maximally activated Erk1, Erk2, p38 MAPK and MAPKAPK2 in 5-10 min. The activation of MAPKAPK2 by SNP was blocked by the soluble guanylyl cyclase inhibitor, 1H-[1, 2,4]oxadiazolol[4,3-a]quinoxalin-1-one (ODQ) and the p38 MAPK inhibitor, SB203580. The activation of Erk1 was insensitive to ODQ but completely blocked by the Mek1 inhibitor PD98059. The membrane-permeable homologue of cGMP, 8-Br-cGMP, also activated p38 MAPK (A(0.5) approximately 50 microM) but not Erk1 and Erk2. These results indicate that p38 MAPK and MAPKAPK2 are activated by SNP in cGMP-dependent pathways, while the Erk1 activation by SNP is independent of cGMP levels.

Animals↗
PubMed2000

The protein Hrb57A of Drosophila melanogaster closely related to hnRNP K from vertebrates is present at sites active in transcription and coprecipitates with four RNA-binding proteins.

The hnRNP K protein is among the major hnRNA-binding proteins with a strong preference for cytidine-rich sequences. We have cloned a Drosophila hnRNP protein closely related to this vertebrate protein. The protein first identified by the monoclonal antibody Q18 is encoded by a gene located in 57A on polytene chromosomes and has been consequently named Hrb57A. The amino acid sequence of the Hrb57A KH domains and their overall organisation in the protein are remarkably similar to the vertebrate proteins. As the hnRNP K in vertebrates the M(r) 55 000 Drosophila Hrb57A/Q18 protein strongly binds to poly(C) in vitro and is ubiquitously present in nuclei active in transcription. On polytene chromosomes it is found in many puffs and minipuffs. Hrb57A/Q18 specifically coprecipitates four other proteins: Hrb87F/P11 a Drosophila hnRNP A1 homologue, the hnRNA-binding protein S5, the RNA recognition motif-containing protein NonA and the RNA-binding zinc finger-containing protein on ecdysone puffs PEP/X4.

Amino Acid Sequence↗
PubMed2000

Calreticulin and calsequestrin are differentially distributed in canine heart.

Cardiac sarcoplasmic reticulum (SR) consists of three continuous yet distinct regions: longitudinal, corbular, and junctional. Ca(2+)uptake, catalyzed by the Ca(2+)-dependent ATPase, is thought to occur throughout the SR whereas Ca(2+)release occurs in the region of the junctional SR. In the SR, Ca(2+)is stored in a complex with Ca(2+)-binding proteins such as calsequestrin. In the present study, the distribution of the high-affinity calcium-binding protein, calreticulin, in canine cardiac SR was determined and compared with the distribution of other SR proteins. Three types of distribution were observed. Many proteins, including the Ca(2+)-ATPase and two mannose-containing glycoproteins (52 and 131 kDa), were present in all subfractions. These proteins were absent or depleted from the sarcolemma-enriched fraction. The ryanodine receptor/Ca(2+)release channel and calsequestrin were localized to the junctional SR. Calreticulin immunoreactivity was detected in fractions containing longitudinal SR but not in fractions enriched in sarcolemma or junctional SR. Hence calreticulin is present in a unique vesicular fraction and the Ca(2+)-binding proteins calreticulin and calsequestrin display different patterns of distribution in canine heart.

Animals↗
PubMed2000

Large bowel obstruction: an unusual presentation of salmonella enterocolitis in infancy.

An infant with a large-bowel obstruction due to Salmonella B enterocolitis is presented. The clinical and radiologic findings were suggestive of Hirschsprung's disease with total colonic aganglionosis. Due to further deterioration, an ileostomy was performed. Pathologic examination disclosed ganglia in the colon. At laparatomy, 1 month later the colon, which was almost completely obliterated, was resected and an ileorectal anastomosis carried out. The patient remained a carrier of a multiple antibiotic-resistant group B Salmonella strain, and 2 months later died as a result of severe gastroenteritis.

Carrier State↗
PubMed2000

Nonrandomized comparison between stent deployment and percutaneous transluminal coronary angioplasty in acute myocardial infarction.

BACKGROUND: Compared with angioplasty, elective stent implantation has improved short-term and long-term outcome with a decrease in abrupt closure and a reduced 6-month restenosis rate. Although primary angioplasty during acute myocardial infarction has improved outcome, recurrent ischemic events and restenosis are still a problem. METHODS: Outcomes for 166 consecutively treated patients who underwent stent insertion procedures within 24 hours after the onset of acute myocardial infarction were compared with those for a similar group of patients (n = 212) who underwent consecutive balloon angioplasty procedures at one tertiary care institution. The objective of this study was to examine in-hospital and late clinical outcomes for the 2 groups. RESULTS: The procedural success rate for stenting in acute myocardial infarction was 100%; that for angioplasty was 98%. Mortality rates during hospitalization were similar for the stent group and the angioplasty group (4.0% vs 2.0%). The rate of in-hospital acute reocclusion necessitating urgent percutaneous reintervention was significantly lower for the stent group (0% vs 3%, P =.02). Six months after the procedure, the stent group had a significantly lower need for revascularization of the infarct-related artery (8% vs 20%, P =.001) and a significantly lower incidence of combined serious clinical events (death, acute occlusion, emergency bypass, target vessel revascularization, and nonfatal myocardial infarction; 12% vs 30%, P =.00003). CONCLUSION: Compared with balloon angioplasty, stent deployment in the setting of acute myocardial infarction was associated with significantly lower frequency of in-hospital acute occlusion and significantly less need for target-vessel revascularization 6 months after myocardial infarction.

Angioplasty, Balloon, Coronary↗
PubMed2000

Prediction of postdischarge complications by predischarge event recordings in infants with apnea of prematurity.

OBJECTIVE: To determine whether predischarge event recording (PDER) can accurately identify preterm infants with resolving apnea of prematurity (AOP) at risk for postdischarge complications. DESIGN: PDER was performed on infants with resolving AOP on caffeine, ready for discharge. The outcome of infants with normal recordings was compared with that of infants with abnormal recordings. Follow-up data were obtained for outcome. RESULTS: Of the 106 infants, 74 had a normal PDER and 32 had an abnormal PDER (apneas lasting for > 20 seconds and/or a heart rate of < 80 beats per minute for > 5 seconds). Birth weight, gestational age at birth, length of stay, discharge weight, and duration of caffeine treatment after discharge were no different between groups. None of the normal PDER infants (0 of 74) had postdischarge complications, whereas 4 of 32 infants with an abnormal PDER had complications (p < 0.05, power = 0.7). The positive predictive value of a normal PDER and no postdischarge complications was 100%. The positive predictive value of an abnormal PDER and an adverse outcome was 12.5%. CONCLUSION: Normal PDER accurately identifies infants at low risk for an adverse outcome.

Apnea↗