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Biomedical subjects

M Shapira

Publications and source records attributed to M Shapira.

At least 55 records · Page 3Linked to original sources
PubMed1993

Intergenic sequences from the heat-shock protein 83-encoding gene cluster in Leishmania mexicana amazonensis promote and regulate reporter gene expression in transfected parasites.

Regulation of expression from hsp83 gene cluster encoding heat-shock protein (HSP) 83 of the protozoan parasite Leishmania mexicana amazonensis (L.m.a) was examined. The first gene from this cluster, along with 8 kb of flanking sequences, was cloned, and intergenic region (IR) sequences were found upstream from the cluster. L.m.a. parasites were electroporated with a plasmid (pICI) in which the chloramphenicol acetyltransferase (CAT)-encoding gene (cat) was cloned between two IRs derived from an internal repeat unit of the hsp83 cluster, resulting in CAT activity at 26 degrees C. Exposure of cells transfected with this plasmid to a 35 degrees C heat shock led to an increase in CAT activity, within a range similar to that observed for the accumulation of hsp83 steady-state mRNA at 35 degrees C. S1 analysis of the hsp83 mRNA showed that the major part of the IR was transcribed and mostly present as 3' non-translated extensions. Deletion analysis of the flanking regions indicated that the presence of IR sequences, both upstream and downstream from cat, was critical to its expression. Partial deletions that removed the original AG splice acceptor site (leaving 289 bp upstream) and downstream IR sequences (leaving 200 bp) did not eliminate CAT activity. However, this combined deletion altered the effect of temperature on cat expression in transfected cells, as compared with the activity measured in cells transfected with the original plasmid.

Amino Acid Sequence↗
PubMed1993

[Changes in diagnosis and treatment of breast pathology at a specialized breast clinic].

The following results highlight the changes that occur when breast pathology is diagnosed and treated at a centralized breast clinic. 2 periods of 1 year each were compared. During the first year breast problems were treated in a general surgical clinic. During the second year all breast problems were diagnosed and treated in a specialized breast clinic, in which a surgeon, radiologist, pathologist and oncologist participated as a team. During the second year 81 patients were operated for breast cancer compared to 56 in the first year and to a mean of 41 in previous years. The rate of lumpectomies in the second year was 60% compared to 45% in the first. A similar number of patients with palpable findings presented in both years and there were 295 fine needle aspirations in the first year vs 290 in the second. Fewer biopsies were done for benign palpable lesions in the second year (28 vs 79) due to better interpretation of benign cytological and mammographic findings. Since diagnosis of the tumor prior to surgery was more accurate in the second year, a more specific consultation with the patient was possible. Treatment options were discussed in greater detail and the patient could therefore participate in the treatment process. The number of fine needle localization biopsies (FNLB) done during the second period was 46, compared to 15 in the first period. Good collaboration between surgeon and radiologist explains the increase in the rates of malignancies found in FNLB in the second period (50% vs 33%).(ABSTRACT TRUNCATED AT 250 WORDS)

Ambulatory Care Facilities↗
PubMed1993

Leishmania mexicana amazonensis: effect of heat shock on the spliced leader RNA and its ribonucleoprotein particle SL RNP.

Trypanosomatid parasites of the genus Leishmania experience a temperature shift from 22-38 degrees C to 33-37 degrees C while being transmitted from the invertebrate vector to the mammalian host. Expression of many protein-coding genes in protozoan parasites that cycle between two hosts have been shown to be thermosensitive, and temperature changes most probably serve as a major regulatory factor during stage differentiation. We present here our studies on effects of physiological temperature shift on the steady-state and nascent synthesis of the spliced leader SL RNA, as well as on its small RNP particle, SL RNP. Northern blot analysis showed no significant changes in the steady-state level of SL RNA at elevated temperatures. Neither were any alterations detected at the two different temperatures in nascent transcription of the SL RNA gene, examined in cells made permeable by treatment with lysolecithin. Fractionation of cell extracts on Cs2SO4 gradients indicated that temperature elevation led to changes in SL RNP particles. Alterations in these particles upon heat shock were also observed by separation on polyacrylamide gels, but only in the presence of urea, indicating that the differences caused by elevation of temperature were revealed exclusively under stringent fractionation conditions.

Animals↗
PubMed1993

Peptic ulcer on a Kibbutz in Israel: 1930-1990.

In the last 30 years, many changes have occurred in the epidemiology and natural history of peptic ulcer disease. During the 60 years since Kibbutz Afikim's beginning, 94 members have been diagnosed with duodenal or gastric ulcer. Seventy-one percent were males, 29% died. Ninety-four percent of the patients were diagnosed by barium meal only. Six patients had a gastric ulcer. The incidence rate among adults was 0.6% through the mid-1940s; the rate decreased to 0.3% by the end of the 1970s and to 0.1% in the 1980s. The decrease was noted for both sexes. The prevalence rate among adults since the 1970s has been 7%. In one-fourth of the patients, an ulcer was diagnosed before age 30 and in another fourth after age 50. An average of 3.1 upper gastrointestinal radiographs were done per patient. There was no temporal relationship between the incidence and the stressful effects of arrival in Israel or at the Kibbutz. Twenty-four patients underwent surgery: In the last decade there seemed to be a slight decrease in elective surgery.

Adult↗
PubMed1993

Direct in-vivo detection of atypical hormonal expression of a Sertoli-Leydig cell tumour following stimulation with human chorionic gonadotrophin.

A 60-year-old woman presented with progressive hirsutism and elevated serum testosterone levels. Selective bilateral ovarian and adrenal vein catheterization demonstrated mild elevated testosterone and androstenedione levels in the right ovarian vein, which increased considerably 15 minutes following intravenous injection of 5000 IU human chorionic gonadotrophin. Androgen levels decreased remarkably after administration of gonadotrophin hormone releasing hormone-agonist (GnRH-a). On histological examination, diffuse stromal hyperplasia of both ovaries was noted, with a small Sertoli-Leydig cell tumour in the right ovary. This is the first report of preoperative, direct selective diagnosis of a small Sertoli-Leydig cell tumour with such a hormonal expression. Ovarian Sertoli-Leydig cell tumours are rare sex cord stromal tumours that exhibit testicular-like structure and differentiation. These tumours are potentially malignant, can cause progressive virilization (Young & Scully, 1985), and are often clinically manifested as palpable pelvic masses and virilization (Meldrum & Abraham, 1979; Friedman et al., 1985). We describe a patient with postmenopausal virilization due to Sertoli-Leydig cell tumour, in whom a remarkable increase in androgens was detected following intravenous human chorionic gonadotrophin injection, during adrenal and ovarian selective vein blood sampling. A remarkable decrease in the serum androgen level was noticed following an injection of gonadotrophin hormone releasing hormone-agonist (GnRH-a).

Androgens↗
PubMed1993

Developmental disabilities among children between birth and 3 years old in the Haifa district: a population study.

The incidence of major neurodevelopmental deficits among children between birth and 3 years of age in the Haifa district was evaluated. Routine standardized developmental screening at the well-baby clinics was employed. The records of all children referred to the only two child developmental centers in the district during a period of 4 years were analyzed. The overall incidence was 31 per 1000 and was lower than expected. The age at diagnosis and associated disorders are discussed. In 30% of the cohort the diagnosis was inaccurate, and a 22% false positive referral rate was noted. A more thorough training in the early diagnosis of psychomotor developmental problems in childhood in the well-baby clinics is indicated.

Child Behavior Disorders↗
PubMed1992

Crohn's disease and the Jews.

Several epidemiologic studies of Crohn's Disease (CD) from the northern hemisphere show high rates of the disease among Jews. Israel has absorbed many Jews from those countries and the rates of CD in Israel are lower than in their place of birth. Important, too, among immigrants from the middle east Mediterranean countries, the rates appear to be higher than those in their countries of origin, where the disease is rare. CD has a genetic predisposition, but we physicians cannot ignore the environmental factors.

Crohn Disease↗
PubMed1991

Usefulness of severity of myocardial ischemia on exercise testing in predicting the severity of myocardial ischemia during daily activities.

To determine the relation between myocardial ischemic indexes on exercise testing and on ambulatory Holter recording, 60 patients with stable coronary artery disease who exhibited an ischemic response to both testing procedures were studied. All patients performed a Bruce protocol exercise test and underwent 24-hour Holter recording within 2 weeks without antianginal medications. Mean exercise duration was 7.4 +/- 2.8 minutes, mean heart rate at 1-mm ST depression was 118 +/- 20 beats/min and mean maximal ST depression during exercise was 2.2 +/- 1 mm. During Holter recording the average number of ischemic episodes was 4.7 +/- 2.6 per patient, mean duration of daily ischemia was 62 +/- 54 minutes, mean maximal ST depression was 3.2 +/- 1.3 mm and average heart rate at 1-mm ST depression was 93 +/- 17 beats/min. Overall, the correlations between ischemic indexes on both testing procedures were very weak (mean r2 = 0.054). The only exercise variable that had a significant correlation (p less than 0.05) with all Holter variables was heart rate at 1-mm ST depression, yet it correlated very weakly (0.064 less than or equal to r2 less than or equal to 0.125) with most Holter covariates and had a better correlation (r2 = 0.256) only with average heart rate at 1-mm ST depression during Holter. Thus, ischemic indexes on exercise testing cannot accurately predict ischemic indexes on ambulatory Holter recording in patients with stable coronary artery disease who exhibit ischemic changes on both tests.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Disease↗
PubMed1990

Temperature-induced expression of proteins in Leishmania mexicana amazonensis. A 22-kDa protein is possibly localized in the mitochondrion.

Temperature increase is an integral part of Leishmania life cycle, and plays a major role in stage transformation. Analysis of the temperature-dependent pattern of protein synthesis on two-dimensional gel electrophoresis shows that, in addition to the conserved heat-shock type of response in which expression of the major 70-kDa and 83-kDa heat-shock proteins is observed, a group of low-molecular-mass (17-40 kDa) proteins is induced in promastigotes of Leishmania mexicana amazonensis at elevated temperatures. Immuno-gold labelling with antibodies raised against the heat-induced 22-kDa proteins was localized mainly in the mitochondrion of Leishmania parasites, though labelling was observed also in the nucleus. The correlation of this finding with various reports on induction of mitochondrial enzymes in response to temperature stress in other organisms is discussed.

Animals↗
PubMed1990

[Multiple enteral fistulas in peritoneal tuberculosis].

A 40-year-old Ethiopian man had abdominal pain for a year and a half, diarrhea and weight loss. Multiple enteral fistulas were diagnosed by X-ray and colonoscopy. During investigation, the differential diagnosis was between Crohn's disease, intestinal lymphoma and intestinal tuberculosis. Therapeutic trial with corticosteroids was unsuccessful. At operation peritoneal tuberculosis was diagnosed and several entero-enteric fistulas were found, but there were no other intestinal lesions nor other foci of tuberculosis. Intestinal fistulas complicating peritoneal tuberculosis are rare in comparison with enteral tuberculosis, lymphoma or Crohn's disease. After the fistulas were closed surgically and antitubercular treatment given, the patient recovered, returned to his normal weight, and had no complaints.

Adult↗
PubMed1989

Heat-shock protein 83 of Leishmania mexicana amazonensis is an abundant cytoplasmic protein with a tandemly repeated genomic arrangement.

The 83-kDa heat-shock protein HSP83 is a highly abundant protein in Leishmania amastigotes and promastigotes exposed to elevated temperature. Antibodies against this protein were obtained by immunization with a synthetic peptide derived from a conserved region. These antibodies recognized both the denatured and the native form of the molecule and were used for immunofluorescence analysis. These experiments, together with analysis by cell fractionation, show that HSP83 is distributed in the cytoplasm of Leishmania parasites. The gene for HSP83 in Leishmania mexicana amazonensis has been cloned from a genomic library, and molecular characterization shows it is present in several copies of 4-kb repeats arranged in tandem.

Animals↗
PubMed1988

Temperature effects on molecular processes which lead to stage differentiation in Leishmania.

We have studied the effects of growth phase and temperature on the morphological and molecular processes that occur during stage differentiation of Leishmania. Parasites which differ in their ability to transform axenically were compared. A typical heat shock response is observed in strains that transform axenically. Heat shock proteins (HSPs) of 70 and 83 kd are transcribed and synthesized along with a decrease in cellular protein synthesis, including tubulin. Changes in the transcription of the tubulin gene are also noted. In strains which do not transform in culture HSPs are induced, but cellular protein synthesis is unaffected and no differences are observed in tubulin transcription and expression. HSPs 70 and 83 remain constitutively expressed in amastigotes. HSP 83 transcription increases along the promastigote growth curve. beta-Tubulin transcription is also affected by growth phase and temperature increase, though alpha-tubulin remains unaltered. An amastigote-like hybridization pattern is induced in heat-shocked promastigotes, in which a larger transcript for beta-tubulin (2.8 kb) becomes dominant and the promastigote transcript (2.4 kb) decreases. Tubulin expression is susceptible to temperature control in Leishmania mexicana amazonensis, though direct correlation to HSP expression was not demonstrated.

Animals↗
PubMed1987

Regulation of the herpes simplex virus type 1 late (gamma 2) glycoprotein C gene: sequences between base pairs -34 to +29 control transient expression and responsiveness to transactivation by the products of the immediate early (alpha) 4 and 0 genes.

The glycoprotein C (gC) gene of herpes simplex virus type 1 is a true late gene, in that its expression occurs late in infection with a strict requirement for viral DNA replication. Recently, we reported on gC expression during infection with mutant viruses carrying deletions in the gC gene promoter. Analysis of RNA extracted from cells infected with individual mutants showed that the DNA sequences required for regulated expression of this late gene lie within bases -34 to +124 relative to the 5' end of the mRNA. In the present study, the deleted gC promoter sequences were fused to the bacterial chlorampheniol acetyltransferase (CAT) gene and expression was measured in short-term transfection assays after transactivation by infection with HSV or cotransfection with a second plasmid carrying the immediate early genes of HSV-1. The 63 base pair sequence located between -34 to +29 on the gC promoter was sufficient to give induction of CAT activity following infection and on cotransfection with plasmids which code for the immediate early gene products ICP4 and ICPO. This 63 base pair region contains the TATA homology and the transcriptional start site of the gC gene, and apparently contains specific promoter elements not found in a similar region of the HSV TK promoter. This was shown by removing the distal upstream region of the TK promoter, 5' to -37, and found that the TK gene was no longer activated by infection or cotransfection with an alpha 4-alpha 0 gene containing plasmid.

Animals↗
PubMed1987

Hepatic ascaridiasis.

Adult Ascaris, which are usually found in the intestine, can enter the ampulla of Vater if the sphincter of Oddi is not efficient. This situation seems common in children; in adults it occurs after endoscopic or surgical sphincterotomy. The worms can then migrate up into the intrahepatic bile ducts and provoke biliary stasis which may become infected and complicated by abscesses. It is inside such abscesses that we may find fragments of adult Ascaris. In the 4 cases reported in the literature during the last 20 years, we note in particular that the clinical signs vary considerably, according to the age of the patient. In children, the parasitic infestation is often massive and the clinical features are extremely serious, namely shock and acute abdominal pain, which lead to a laparotomy being done. In adults, the clinical feature is that of a biliary infection. Here we describe a fifth case of hepatic ascaridiasis which differs from the others in that the diagnosis was established by ERCP and CT scan and that treatment was medical.

Aged↗
PubMed1985

Specificity and cross-reactivity of synthetic peptides derived from a major antigenic site of influenza hemagglutinin.

A synthetic peptide corresponding to sequence 138-164 of influenza hemagglutinin elicited in rabbits antibodies that recognized different parts of the peptide, namely the loop region (139-146) and the rest of the peptide, region 147-164. This was shown both by direct binding and by competitive-inhibition experiments. Individual antisera differed in their specificity. The contribution of the Asp residue at position 144 to the antigenic specificity was shown in various inhibition assays. These data are in accordance with the reported effect of the exchange Gly----Asp on the serological specificity of influenza virus.

Animals↗
PubMed1985

A synthetic vaccine against influenza with built-in adjuvanticity.

In a previous publication we demonstrated that an anti-viral response against influenza can be achieved by immunization with a conjugate of the synthetic peptide corresponding to the sequence 91-108 of the hemagglutinin, when administered in complete Freund's adjuvant. In the present study we compare the adjuvant activity of the synthetic MDP with that of CFA and alum, in the above mentioned immunological system. The level of anti-peptide antibodies raised by the three adjuvants was similar, with only slight variations, yet, only CFA led to significant cross reaction with the virus. Nevertheless, MDP, when linked covalently to the conjugate (91-108)-TT was an efficient substitute for CFA in inducing anti viral protection against in vivo challenge infection. The administration of free MDP in a mixture with the peptide-toxoid conjugate did not lead to a significant protection.

Acetylmuramyl-Alanyl-Isoglutamine↗