PubMed Health⌕ Search

Biomedical subjects

O Zamir

Publications and source records attributed to O Zamir.

At least 19 recordsLinked to original sources
PubMed1996

Laparoscopic-modified Nissen fundoplication in children with familial dysautonomia.

Children with familial dysautonomia (FD) often require an antireflux operation and gastrostomy to prevent the detrimental effects of aspirated gastric juice on the lungs and to facilitate liquid feeding. The aim of this study was to examine whether a laparoscopic procedure in such patients is as safe and effective as the traditional open technique. The data for all pediatric patients who underwent a laparoscopic antireflux procedure for familial dysautonomia were reviewed and compared with those the last pediatric patients with FD who were operated upon using the open technique, before the introduction of the laparoscopic procedure. Of the 61 children who underwent an antireflux procedure for FD (1978-1996), 13 were operated on laparoscopically. The authors found that the postoperative course of these patients was less complicated than that of patients who had the traditional laparotomy procedure. There was no need for mechanical ventilation during the postoperative course, and there were no respiratory complications. The mean hospitalization period was significantly shorter (7.9 days v 13.2 days). There were no complications attributable to laparoscopy, and the antireflux procedure has been effective in all patients (short-term follow-up). The authors conclude that laparoscopic procedures that include a modified Nissen fundoplication, gastrostomy, and appendectomy are feasible and as safe as conventional surgery for the treatment of FD in children. It appears that this approach has fewer complications than laparotomy, might reduce the need for postoperative mechanical ventilation, and is associated with a shorter postoperative stay.

Adolescent↗
PubMed1996

Laparoscopic splenectomy for immune thrombocytopenic purpura.

Splenectomy is an effective treatment for immune thrombocytopenic purpura (ITP). The recent advances in laparoscopic technique and technology have made laparoscopic splenectomy a viable option. Over 36 months we performed a total of 17 laparoscopic splenectomies, 15 of them for ITP and 2 for familial spherocytosis. We present our initial experience with laparoscopic splenectomy in 15 patients (age 16-71 years) with ITP. Operations were performed 2-24 months after the establishment of the diagnosis and initiation of appropriate therapy. Technically, the splenic artery was clipped first; the lower pole of the spleen and its posterolateral attachments were dissected using endoclips and electrocautery; the hilum and short gastric vessels were separated using an endostapler; the spleen was placed in a plastic bag, its opening pulled out through the umbilical incision, and the spleen fragmented and aspirated out of the bag. Operations lasted 100-300 min (mean 170 min). No patient required blood transfusion. The postoperative course was uneventful in all patients with minimal requirement of analgesia and early return to normal activity. Platelet counts returned to normal in all patients in a follow-up period of 2-36 months. Laparoscopic splenectomy is safe and effective for patients with ITP because of reduced operative trauma, less postoperative pain, cosmetic advantage, and possibly less postoperative complications.

Adolescent↗
PubMed1996

Thrombin stimulates atrial natriuretic peptide secretion from rat cardiac atrium.

Atrial natriuretic peptide (ANP) is a hormone secreted predominantly by atrial myocytes. Although atrial distension is the primary stimulus of ANP secretion, several hormones have also been implicated in the regulation of ANP secretion. alpha-Thrombin, a serine protease participating in the blood coagulation system, has additional hormone-like effects in several cell types, apparently via interaction with specific cell surface receptors. Here we report that alpha-thrombin enhanced ANP secretion from isolated rat atrium within 10 min, in a concentration-dependent manner. The protease also significantly increased ANP release from cultured atrial myocytes, in a concentration-dependent manner. The alpha-thrombin-induced release of ANP from cultured atrial myocytes was completely abolished by hirudin, a specific alpha-thrombin protease inhibitor. Furthermore, synthetic peptides, identical in their amino acid sequence to the N-terminal segment of the proteolytically cleaved thrombin receptor, enhanced ANP release from adult rat cultured atrial myocytes. Our data suggest that thrombin may regulate ANP release from the cardiac atrium. This action involves activation of thrombin receptors in atrial myocytes.

Animals↗
PubMed1996

Erythropoietin stimulates atrial natriuretic peptide secretion from adult rat cardiac atrium.

Hypoxia is a powerful stimulus for erythropoietin (EPO) secretion from the kidney and for atrial natriuretic peptide (ANP) secretion from atrial myocytes. EPO is involved in the long term defense mechanism against hypoxia via stimulation of erythropoiesis. ANP is involved in the short-term defense mechanism against hypoxia via improved pulmonary and heart functions. We investigated a possible interaction between these two hormones. We tested the hypothesis that EPO may stimulate ANP secretion from the cardiac atrium. This hypothesis was tested in two in vitro models; isolated rate atrium and cultured adult atria rat myocytes. Recombinant human EPO (5-10 units/ml) enhanced ANP secretion from the isolated atrium (by approximately 2-fold) within 10 min in a concentration-dependent manner. To define whether the action of EPO on ANP secretion is direct, we examined the effect of EPO on ANP release from adult rat cultured atrial myocytes. EPO failed to stimulate ANP secretion from cultured atrial myocytes, suggesting that EPO-induced ANP secretion is an indirect effect. Cyclooxygenase products (e.g.,prostaglandins) and endothelin 1 were shown to be potent secretagogues of ANP from cardiac atrium. To test whether EPO-induced ANP secretion from isolated perfused atrium is mediated by cyclooxygenase products and/or endothelin, we used inhibitors of the enzyme cyclooxygenase (indomethacin or aspirin) and the endothelin receptor ETA subtype antagonist BQ123. EPO-stimulated ANP secretion was not affected by indomethacin (10(-4) M) or aspirin (10(-4) M), whereas BQ123 (10(-6) M) completely abolished EPO-stimulated ANP secretion from cardiac atrium. Our results expand our knowledge on the interaction between EPO and ANP hormonal systems and the possible role in the acute defense mechanism against hypoxia.

Animals↗
PubMed1995

Spread of lumpy skin disease in Israeli dairy herds.

Fourteen of the 17 dairy herds in Peduyim, an Israeli village, became infected with lumpy skin disease during a period of 37 days in August and September 1989. One cow in one neighbouring village and four cows in another neighbouring village also became infected, probably through being treated by a veterinarian who treated cows in Peduyim. Circumstantial evidence suggests that the original infection was brought to Peduyim and spread by stable flies (Stomoxys calcitrans) carried by the wind from foci of the disease at El Arish in northern Sinai, or at Ismailiya and the Nile delta in Egypt. All the cattle and the small flocks of sheep and goats in the village were slaughtered.

Animals↗
PubMed1995

[Laparoscopic colonic resection].

We present our initial experience with laparoscopic colonic resection in 15 patients: adenocarcinoma of the colon, 10 cases, giant villous adenoma (2), arteriovenous malformation (2), and a case of benign stricture. Mean operating time was 190 minutes and there were no intraoperative complications. The margins of resection and number of resected lymph nodes in patients with malignancy were comparable to those in the conventionally operated. Mean postoperative hospital stay was 6.1 days. During a maximum follow-up of 15 months there were no wound or trocar-site recurrences. We conclude that laparoscopic colonic resection is technically feasible and safe. However, its use for treating malignant diseases of the colon needs further study.

Adenocarcinoma↗
PubMed1995

[Laparoscopic splenectomy for immune thrombocytopenic purpura].

Splenectomy is effective in treating immune thrombocytopenic purpura (ITP). Recent advances in laparoscopic technique and technology have made laparoscopic splenectomy feasible. We performed it in 8 cases of ITP (16-34 years old, and 2-24 months after the diagnosis was made and appropriate treatment started). Indications for splenectomy were no response to corticosteroid therapy (2 patients), decrease in platelet count when attempting to taper off therapy (3), or severe side-effects of the treatment (3). 4-5 ports were used. The splenic artery was first double-clipped through an opening in the gastrocolic ligament and then the lower splenic pole and the posterolateral attachments were dissected using endoclips and electrocautery. The hilum and short gastric vessels were separated using an endostapler. The spleen was placed in a plastic bag whose open end was pulled out through an umbilical incision and the spleen fragmented and aspirated out of the bag, while it was still inside the abdomen. Blood or platelet transfusions were not needed and the postoperative course was uneventful in all, with early return to full normal activity. Postoperatively, platelets increased to more than 150,000/mm3 in all patients, and there was no further need for corticosteroids during a follow-up of 2-12 months. We recommend laparoscopic splenectomy for ITP because of the reduced operative trauma, better recovery and rehabilitation, less postoperative pain, cosmetic advantage, and possibly fewer postoperative complications.

Adolescent↗
PubMed1995

[Laparoscopic cholecystectomy in high risk patients].

Of approximately 600 laparoscopic cholecystectomies performed between October 1991-April 1994, 21 were in patients categorized as "high operative risks." The indications for operation were: symptomatic gallstones, 9 patients, state after acute cholecystitis treated medically (8), state after acute cholecystitis treated by cholecystostomy (3), and 1 patient with acute cholecystitis unresponsive to medical treatment. Operative risk according to ASA grading was II-III in 7 patients, III in 10, III-IV in 2 and IV in 2 (group average ASA III). They were prepared for operation by optimizing their various medical conditions. 4 with severe cardiac disease (ASA III-IV and IV) underwent laparoscopic cholecystectomy with close monitoring of hemodynamic status via radial artery and pulmonary artery catheters. Following surgery, they were monitored in the surgical intensive care unit for 12-24 hours. There were no complications during or following operation. The mean postoperative stay in hospital was 1.9 days (range 1-3). All patients were able to return to their preoperative life styles and activities. High operative risk is not a contraindication to laparoscopic cholecystectomy.

Cholecystectomy, Laparoscopic↗
PubMed1995

Comparative evaluation of microagglutination test and serum agglutination test as supplementary diagnostic methods for brucellosis.

The diagnosis of brucellosis in cattle and small ruminants requires the use of more than one serological test. The complement fixation test (CFT), the rose bengal test (RBT), and the serum agglutination test (SAT) are among the most useful tests for routine diagnosis. The microagglutination test (MAT) was developed as a simpler and more efficient test than the SAT. The relative efficacy of this test compared with that of the SAT was evaluated by using brucella-free sheep and goats prior to and after vaccination treatment. The specificities of the MAT and the SAT were 100%. Of the ewes and goats with a vaccination history, one ewe, expectedly a negative responder, had reactions in the MAT, the complement fixation test, and the rose bengal test but not in the SAT, suggesting a lower sensitivity of the SAT in this case. The calculated sensitivities of the MAT and the SAT were 93.9%. The agreement between MAT and SAT results from nonresponders was examined by using sera from unvaccinated lambs and kids (95.2% agreement), unvaccinated ewes and goats (84.4%), and ewes and goats with a vaccination history (43.9%). For the latter group higher levels of agglutination units were observed by the MAT than by the SAT in 51.5% of the samples. In testing sera from positive reactors after vaccination neither method was superior (MAT values were greater than SAT values for 23.5% of the samples, and MAT values were less than SAT values for 21.9% of the samples). Comparison of the methods on the individual sample level revealed a significant correlation between the MAT and the SAT (r = 0.96 +/- 0.005; P < 0.001). Since the MAT is simpler to perform than the SAT and can potentially be automated, the inclusion of the MAT as a supplementary test in brucellosis control programs is recommended.

Agglutination Tests↗
PubMed1995

Effects of ANP receptor antagonists on ANP secretion from adult rat cultured atrial myocytes.

Atrial natriuretic peptide (ANP) is a hormone-secreted predominantly by atrial myocytes. ANP exerts many of its actions via activation of the particulate guanylyl cyclase receptor ANPR-A and the formation of guanosine 3',5'-cyclic monophosphate (cGMP), which serves as a second messenger in the target cells. Using membrane-permeable cGMP analogues (8-bromo-cGMP and dibutyryl- cGMP), we first tested the hypothesis that ANP secretion by adult rat cultured atrial myocytes can be modulated through the second messenger cGMP. Second, we examined the effects of two competitive ANPR-A receptor antagonists, namely HS-142-1 and anantin, on cGMP formation and ANP secretion from cultured atrial myocytes. Cultured atrial myocytes secreted large quantities of immunoreactive (ir) ANP under basal conditions. We found that cGMP analogues inhibited basal irANP secretion from cultured atrial myocytes, whereas HS-142-1 and anantin had stimulating effects. HS-142-1 and anantin reduced cGMP formation in cultured atrial myocytes at basal conditions. These results suggest an autoregulatory mechanism of ANP secretion by atrial myocytes in an autocrine/paracrine fashion.

Animals↗
PubMed1995

[Laparoscopic surgery in children and adolescents].

Laparoscopic surgery is a rapidly developing field in general surgery. The advantages of laparoscopic procedures are short postoperative courses, fewer wound-related complications, possible reduction in rate of late postoperative adhesions and better cosmetic results. Laparoscopic procedures are indicated in well-defined clinical settings, after enough experience has been acquired and technical problems solved. Children and adolescents may also benefit from laparoscopic procedures. The technique is suitable for cholecystectomies, appendectomies in selected cases, splenectomies, anti-reflux procedures, bowel resections, and diagnostic procedures, among others. In the past 3 years we have performed 65 laparoscopic procedures in patients younger than 17 years, including 10 cholecystectomies, 31 appendectomies and 7 Nissen fundoplications.

Adolescent↗
PubMed1994

Adverse reactions in cattle to a capripox vaccine.

Capripox vaccine (strain 0240) caused severe generalised skin reactions in vaccinated dairy cattle in two herds, whereas beef cattle did not develop reactions. All the reacting animals developed lumpy skin disease-like lesions. The incidence of skin lesions in first-lactation cows in herd A was 22.9 per cent and in herd B 29.3 per cent, mainly in the post-calving period. In older cows, the incidence was 10 per cent in herd A and 12.4 per cent in herd B. In herd B the high-yielding lactating cows were the most severely affected. There was a decrease of 3.5 per cent in milk production in each herd over a period of 12 days, and six first calving animals (3.5 per cent) and six cows (1.5 per cent) were slaughtered. A capripox virus was isolated from the animals with severe lesions, and was also demonstrated by electron microscopy. The histopathological lesions were similar to those of lumpy skin disease. The extent of the lesions appeared to be stress-related and, to a lesser degree, correlated with age and breed.

Animals↗
PubMed1994

Reduced muscle protein breakdown in septic rats following treatment with interleukin-1 receptor antagonist.

1. The role of interleukin-1 (IL-1) in sepsis-induced muscle proteolysis was assessed by treating septic rats with recombinant IL-1 receptor antagonist (rIL-1ra). 2. In initial experiments, we tested the effectiveness of IL-1ra in preventing muscle proteolysis induced by administration of IL-1. 3. When normal rats were treated with rIL-1 alpha (three intraperitoneal doses of 100 micrograms/kg body weight each over 16 hr), total and myofibrillar muscle protein breakdown rates, measured as release of tyrosine and 3-methylhistidine, respectively, by incubated extensor digitorum longus muscles, were significantly increased. 4. This metabolic response to IL-1 alpha was completely abolished by rIL-1ra, administered as three intraperitoneal doses of 3 mg/kg body weight each over 16 hr. 5. In subsequent experiments, sepsis was induced in rats by cecal ligation and puncture (CLP); non-septic rats were sham-operated. 6. Treatment of septic rats over 16 hr with a total dose of 25 mg/kg body weight of rIL-1ra reduced, but did not normalize, the increased muscle protein breakdown rates seen during sepsis. 7. When the dose of rIL-1ra was more than doubled and given as a constant infusion at a rate of 4.2 mg/kg body weight/hr for 16 hr, the increased rate of muscle proteolysis in septic rats was normalized. 8. The present study offers the first direct evidence that IL-1 is involved in the regulation of muscle proteolysis during sepsis.

Animals↗
PubMed1993

In vivo administration of interleukin-1 alpha induces muscle proteolysis in normal and adrenalectomized rats.

The effect on muscle protein turnover of recombinant interleukin-1 alpha (rIL-1 alpha), 300 micrograms/kg body weight (BW) administered intraperitoneally (IP) in three divided doses over 18 hours, was studied in rats. Protein synthesis rate was determined by measuring incorporation of 14C-phenylalanine into protein, and total and myofibrillar protein breakdown rates were determined by measuring release of tyrosine and 3-methylhistidine, respectively, in incubated extensor digitorum longus muscles. To assess the role of glucocorticoids in rIL-1 alpha-related metabolic alterations, plasma levels of corticosterone following rIL-1 alpha injection and the effect of rIL-1 alpha on muscle protein breakdown in adrenalectomized and sham-adrenalectomized rats were determined. Total and myofibrillar protein breakdown rates were increased by 45% and 167%, respectively, following treatment of normal rats with rIL-1 alpha; muscle protein synthesis was not altered by the cytokine. Plasma corticosterone levels were markedly elevated following rIL-1 alpha injection, with a maximal level occurring at 30 minutes. However, administration of rIL-1 alpha resulted in increased total and myofibrillar protein breakdown rates in both adrenalectomized and sham-adrenalectomized rats. The results suggest that increased muscle proteolysis following administration of rIL-1 alpha is independent of glucocorticoids.

Adrenal Glands↗
PubMed1993

Evidence that inhibition of muscle amino acid uptake during endotoxemia is not mediated by glucocorticoids.

Sepsis and endotoxemia are associated with increased muscle protein breakdown and inhibited amino acid uptake. Glucocorticoids are important for the regulation of muscle protein breakdown in catabolic conditions; in contrast, the role of glucocorticoids in the regulation of muscle amino acid transport during sepsis or endotoxemia is not known. The present study was designed to test the role of glucocorticoids in the regulation of muscle amino acid uptake during endotoxemia. Amino acid transport, determined as uptake of 3H-alpha-aminoisobutyric acid (AIB) by incubated soleus muscles in vitro, was reduced by approximately 40% 2 hours after intraperitoneal (IP) injection of 10 micrograms/kg endotoxin in rats. Administration of 5 mg/kg of the glucocorticoid receptor antagonist RU 38486 2 hours before endotoxin injection did not affect the inhibition of amino acid uptake. In vitro addition of plasma from endotoxemic rats to incubated rat soleus muscles inhibited amino acid uptake by approximately 30%. This effect of endotoxic plasma also was noted when muscles were from rats that had been treated with RU 38486 and when RU 38486 was present in the incubation medium. Results confirm previous reports of reduced muscle amino acid transport during endotoxemia and of the presence of a circulating factor that inhibits muscle amino acid uptake in this condition. Data suggest that inhibited muscle amino acid transport during endotoxemia is not regulated by glucocorticoids.

Aminoisobutyric Acids↗
PubMed1993

Effect of tumor necrosis factor or interleukin-1 on muscle amino acid uptake and the role of glucocorticoids.

Muscle amino acid uptake is inhibited during sepsis and endotoxemia. Cytokines, in particular tumor necrosis factor (TNF) and interleukin-1 (IL-1), have been implicated as mediators of metabolic alterations in sepsis and other critical illness. In this study, we examined the effect of TNF and IL-1 on muscle amino acid uptake and tested the hypothesis that cytokine-induced changes in muscle amino acid uptake are mediated by glucocorticoids. Intraperitoneal injection in rats of 100 micrograms per kilogram body weight of human recombinant TNF alpha (rTNF alpha) or rIL-1 alpha resulted, two hours later, in 36 and 24 percent reduction, respectively, of amino acid transport in incubated soleus muscles, determined as intracellular uptake of alpha-aminoisobutyric acid. When rats were treated with the glucocorticoid receptor antagonist RU 38486 (5 milligrams per kilogram of body weight) two hours before cytokine injection, the inhibitory effect on muscle amino acid transport of TNF was blocked, whereas that of IL-1 was unaffected. The present results suggest that TNF and IL-1 may regulate amino acid transport in skeletal muscle and that the effect of TNF, but not that of IL-1, is at least partly mediated by glucocorticoids.

Amino Acids↗
PubMed1992

Increased intestinal protein synthesis during sepsis and following the administration of tumour necrosis factor alpha or interleukin-1 alpha.

The influence of sepsis on intestinal protein synthesis was studied in rats. Sepsis was induced by caecal ligation and puncture (CLP); control rats were sham-operated. Protein synthesis was measured in vivo in the jejunum and ileum following a flooding dose of [14C]leucine. At 8 h after CLP the protein synthesis rate was increased by approx. 15% in jejunal mucosa, and at 16 h after CLP, the protein synthesis rate was increased by 50-60% in the mucosa and seromuscular layer of both jejunum and ileum. In a second series of experiments, rats were treated with recombinant tumour necrosis factor alpha (rTNF alpha) or recombinant interleukin-1 alpha (rIL-1 alpha) administered at a total dose of 300 micrograms/kg body weight over 16 h. Control rats received corresponding volumes of solvent. Treatment with rTNF alpha resulted in an approx. 25% increase in mucosal protein synthesis in jejunum. Following treatment with rIL-1 alpha, protein synthesis increased by 25% in jejunal mucosa and almost doubled in ileal mucosa. The results suggest that sepsis stimulates intestinal protein synthesis and that this response may, at least in part, be mediated by TNF and/or IL-1.

Animals↗