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Biomedical subjects

A Segal

Publications and source records attributed to A Segal.

At least 37 records · Page 2Linked to original sources
PubMed1999

Reconstitution of GTPgammaS-induced NADPH oxidase activity in streptolysin-O-permeabilized neutrophils by specific cytosol fractions.

GTPgammaS activates the NADPH oxidase and this activity declines rapidly with time after preexposure to streptolysin O. This was not due to loss of p47(phox), p67(phox), or Rac. To identify the component(s) leaking out of the permeabilized cell responsible for loss of activity, a GTPgammaS-dependent reconstitution assay was established. Neutrophil cytosol was subjected to chromatographic fractionation steps for purification of the minimum fraction required to restore activity. The reconstitution of the GTPgammaS-stimulated activity was dependent on ATP. The inhibitors staurosporine and calphostin C greatly reduced the activity in the reconstitution assay, implicating the involvement of a protein kinase C (PKC) pathway. PKC isoforms beta and delta were eliminated as the active factors in the most pure reconstitution fraction. With this novel cell-based reconstitution assay, we have identified the requirement for a protein kinase, or its substrate, for the restoration of GTPgammaS activation of the NADPH oxidase.

Bacterial Proteins↗
PubMed1999

Expression and localization of cyclo-oxygenase isoforms in non-small cell lung cancer.

The beneficial effects of cyclo-oxygenase (COX) inhibitors in both colon cancer and adenomatous polyps suggest a role for the prostanoid pathway in epithelial malignancy. Although variable prostanoid synthesis in non-small cell lung cancer (NSCLC) has been demonstrated in freshly obtained tissue, COX messenger ribonucleic acid (mRNA) and protein localization in such tumours had not been investigated ex vivo. Thirty-four cases of primary NSCLC were examined for both constitutive (COX-1) and inducible COX (COX-2) by means of in situ hybridization and immunohistochemistry. COX-1 mRNA expression was absent or below the level of detection via in situ hybridization. COX-1 immunohistochemistry demonstrated uniform faint cytoplasmic staining in tumour cells and stromal inflammatory cells. Semiquantitative analysis of COX-2 expression in NSCLC demonstrated the highest levels of both mRNA and protein in adenocarcinoma cells (n=10, p<0.005 compared with large cell and squamous cell carcinoma), intermediate and variable expression in large cell carcinoma (n=11) and low or absent expression in squamous cell tumours (n=13). Levels of COX-2 expression in infiltrating inflammatory cells was the same in all tumour types. In conclusion, tumour cell cyclo-oxygenase-2 rather than cyclo-oxygenase-1 expression may account for the variable prostanoid production seen in non-small cell lung cancer, and primary lung adenocarcinoma expresses the highest levels of cyclooxygenase-2. Assessment of cyclo-oxygenase-2 expression ex vivo should be performed in studies examining the potential therapeutic effects of cyclo-oxygenase inhibitors in non-small cell lung cancer.

Carcinoma, Non-Small-Cell Lung↗
PubMed1999

Results of gastrointestinal evaluation in 90 hospitalized iron deficiency anemia patients.

BACKGROUND: Chronic occult blood loss from the gastrointestinal tract is widely accepted as a major cause of iron deficiency anemia. OBJECTIVES: To evaluate the diagnostic yield of gastroscopy, colonoscopy and fecal occult blood testing of hospitalized IDA patients, plus follow-up. METHODS: IDA was defined as hemoglobin < 12.5 g/dl (men) and 11 g/dl (women), and serum iron < 50 g/dl. The study group comprised 90 patients (42% male) with a mean age of 65 +/- 15 years and mean Hb 8.1 g/dl. RESULTS: Gastroscopy and colonoscopy revealed a bleeding source in 28.8% and 14.4% respectively. Gastrointestinal symptoms were found in 23% of patients with diseases of the upper gastrointestinal tract and in 15.3% of the lower. The sensitivity of fecal occult blood tests in detecting lesions in the lower and upper GI tracts was 100% and 30.7% respectively. Forty-four patients (48.9%) were discharged from the hospital with IDA of unknown origin. Over the following year, 20 of the 44 patients required further hospitalization, and of these, 13 were found to have anemia. Of the remaining 24 patients who were not hospitalized again, 15 had anemia. Four patients (9%) had significant gastrointestinal lesions and two died during the follow-up. CONCLUSIONS: Fecal occult blood is a sensitive examination for lower but not for upper GI tract lesions.

Adult↗
PubMed1999

[The tribulations of the mysterious Dr. B...., precursors of the endoscopy].

The author is an experienced student of the origins and development of endoscopy from its beginnings with the speculum. Among the various contributors in this field in the medical literature of the 19th century appear the mysterious doctors B.....I. These names were the result of alterations, modifications and misspellings of the same name. Such entries became so ingrained in the literature they were hardly contested. One of the essential tasks of the historian is to verify and criticize even primary sources (Marc Bloch). This is especially true of early documents, no matter how surprising and enthusiastic they may be.

Endoscopy↗
PubMed1998

Granulomatous glomerulonephritis in intravenous drug users: a report of three cases in oxycodone addicts.

Various well-documented renal lesions are associated with intravenous drug use; however, intraglomerular mesangial granulomas have not been previously described. We report three patients who developed an unusual granulomatous glomerulonephritis and interstitial nephritis after intravenous injection of oxycodone, derived from suppositories. Granulomas were seen in an intraglomerular mesangial and also interstitial location. In both sites, the granulomas were associated with filamentous material, presumably derived from a component of the suppositories. This material was periodic acid-Schiff-positive, but negative with Congo red and silver stains. Ultrastructurally, the filamentous material was seen within the mesangial granulomas and also in a subendothelial location, suggesting derivation from the circulation with subsequent transport across the basement membrane and accumulation in the mesangium, where a granulomatous reaction was elicited. All patients developed a degree of renal failure; two of the patients require hemodialysis 20 and 30 months after presentation.

Adult↗
PubMed1998

Helicobacter pylori and peptic ulcer disease therapies: a survey of gastroenterologists in Israel.

BACKGROUND: Eradication of Helicobacter pylori has become a therapeutic option in the treatment of patients with peptic ulcer disease. The aim of this study was to evaluate the current management strategies of Israeli gastroenterologists in the diagnosis and treatment of H. pylori-related peptic ulcer disease, 14 years after the discovery of H. pylori. MATERIALS AND METHODS: A questionnaire was mailed to all specialists in gastroenterology, members of the Israel Gastroenterological Association (IGA). Replies were received from 60% of Israel Board-certified gastroenterology specialists. RESULTS: Over 89% of the gastroenterologists (89.1%) noted that they recommend anti-H. pylori treatment. 94.5% said that they treat duodenal ulcer in the first presentation with anti-H. pylori medication and 75% said that they do so in cases of recurrent duodenal ulcer. According to the replies received, there is a strong consensus towards triple treatment as the favored anti-H. pylori treatment; no one noted the use of dual treatment. Seven-day triple treatment was prescribed by 83.6% of the gastroenterologists who responded. Of these, the great majority, 89.1%, stated that they use proton pump inhibitors (PPI) in combination with any two of the following antibiotics: metronidazole (47.3%), tinidazole (29.1%), clarithromycin (61.8%), and amoxicillin (40%). CONCLUSION: At the time of the survey, most Israel Board-certified gastroenterology specialists prescribed triple anti-H. pylori treatment of one-week's duration.

Amoxicillin↗
PubMed1998

[Eugene de Séré (1828-1870), inventor of the electric lancet].

The authors relate chiefly medical-officer Eugene de Sere's military career, particuliarly some parts of his work: the invention of a galvano-cautery, an electric cutter including a scale which allows to change current strength whether it is needing to cut flesh or to coagulate blood. That instrument is the forerunner of every modern one.

Electricity↗
PubMed1998

[Paleopathology of the relics of Saint Albert of Louvain].

The author recounts St. Albert of Lowen's story who was slaughtered in Reims in 1192 and after buried inside the cathedral's nave. During 1612, at request of the Archduke and Archduchess of Brabant, the King of France and the Reims Archbishop conceded the translation of the relics to Brussels. However an error on the burial place was revealed more ever by the consequences of the Great War. Indeed, the architect Henri Deneux found the genuine tomb of Albert of Lowen. The Belgian people had received the mortal remains of Archbishop Odalric about who skull examination indicated also a traumatic lesion but the death circumstances are ignored. The error of the Reims Cathedral's Canons may be explained by various modifications and above the later transformation, particularly those of the rood-screen.

Belgium↗
PubMed1997

The two common mutations causing factor XI deficiency in Jews stem from distinct founders: one of ancient Middle Eastern origin and another of more recent European origin.

Previous studies showed that factor XI (FXI) deficiency commonly observed in Ashkenazi Jews is caused by two similarly frequent mutations, type II (Glu117stop) and type III (Phe283Leu) with allele frequencies of 0.0217 and 0.0254, respectively. In Iraqi Jews, who represent the ancient gene pool of Jews, only the type II mutation was observed with an allele frequency of 0.0167. In this study we sought founder effects for each mutation by examination of four FXI gene polymorphisms enabling haplotype analysis in affected Jewish patients of Ashkenazi, Iraqi, and other origins and in Arab patients. Initial population surveys of 387 Middle Eastern Jews (excluding Iraqi Jews), 560 North African/Sephardic Jews, and 382 Arabs revealed allele frequencies for the type II mutation of 0.0026, 0.0027, and 0.0065, respectively. In contrast, the type III mutation was not detected in any of these populations. All 60 independent chromosomes bearing the type III mutation were solely observed in Ashkenazi Jewish patients and were characterized by a relatively rare haplotype. All 103 independent chromosomes bearing the type II mutation in patients of Ashkenazi, Iraqi, Yemenite, Syrian, and Moroccan Jewish origin and of Arab origin were characterized by another distinct haplotype that was rare among normal Ashkenazi Jewish, Iraqi Jewish, and Arab chromosomes. These findings constitute the first example of a mutation common to Ashkenazi Jews, non-Ashkenazi Jews, and Arabs and are consistent with the origin of type II mutation in a founder before the divergence of the major segments of Jews. Our findings also indicate that the type III mutation arose more recently in an Ashkenazi Jewish individual.

Africa, Northern↗
PubMed1997

Naturally occurring mutations in the human 5-lipoxygenase gene promoter that modify transcription factor binding and reporter gene transcription.

Five lipoxygenase (5-LO) is the first committed enzyme in the metabolic pathway leading to the synthesis of the leukotrienes. We examined genomic DNA isolated from 25 normal subjects and 31 patients with asthma (6 of whom had aspirin-sensitive asthma) for mutations in the known transcription factor binding regions and the protein encoding region of the 5-LO gene. A family of mutations in the G + C-rich transcription factor binding region was identified consisting of the deletion of one, deletion of two, or addition of one zinc finger (Sp1/Egr-1) binding sites in the region 176 to 147 bp upstream from the ATG translation start site where there are normally 5 Sp1 binding motifs in tandem. Reporter gene activity directed by any of the mutant forms of the transcription factor binding region was significantly (P < 0.05) less effective than the activity driven by the wild type transcription factor binding region. Electrophoretic mobility shift assays (EMSAs) demonstrated the capacity of wild type and mutant transcription factor binding regions to bind nuclear extracts from human umbilical vein endothelial cells (HUVECs). These data are consistent with a family of mutations in the 5-LO gene that can modify reporter gene transcription possibly through differences in Sp1 and Egr-1 transactivation.

Alleles↗
PubMed1997

Glycogenosis type II: a juvenile-specific mutation with an unusual splicing pattern and a shared mutation in African Americans.

The recessively inherited deficiency of acid alpha-glucosidase (GAA) called Glycogenosis Type II is expressed as three different phenotypes: infantile, juvenile, and adult. At the molecular level, infantile and adult forms of the disease have been extensively studied, but little is known regarding the genetic defects associated with the juvenile form. We describe a novel mutation that defines the intermediate juvenile phenotype in a compound heterozygous patient. A transversion of t to g in intron 6 at position -22 creates a cryptic acceptor site and results in unusual splicing abnormality: insertion of 21 nucleotides of the intronic sequence into mRNA and removal of exon 6 without disruption of the reading frame. The second mutation, Arg854Stop in exon 18, had been previously identified in another African-American patient (Hermans et al., 1993a). Family study indicates that a silent allele harboring the Arg854Stop mutation in our patient is inherited from the patient's father, who is also African-American, thus suggesting a common mutation in this population.

Base Sequence↗
PubMed1997

A radiation hybrid map of human chromosome 5 with integration of cytogenetic, genetic, and transcript maps.

One of the major goals of the human genome project is to establish a physical map of each human chromosome with a density of sequence-tagged site (STS) markers exceeding one every 100 kb. We report here the generation of a human chromosome 5-specific radiation hybrid (RH) map that includes 556 markers. Of these markers, 132 loci are ordered with a maximum likelihood ratio of >1000:1 compared with the next most likely order. An additional 113 loci were ordered relative to these backbone markers with a maximum likelihood ratio of >10:1 but <1000:1. Together, these 245 loci form an ordered framework map for the chromosome. Using this framework, >300 more markers were localized based on two-point analysis with the ordered set. On average, there are 50 markers in common with the RH map presented here and other chromosome 5 maps included in the current whole genome cytogenetic, genetic, and physical maps. The accuracy of all the maps is evident in that there are no more than two discrepancies between any one of them and these data. All of the maps encompassing chromosome 5 complement each other providing excellent STS coverage with >2200 loci combined. The chromosome 5-specific RH map contains 20% of these independent loci. In addition, our RH map contains STSs derived from clones suitable for fluorescent in situ hybridization, allowing alignment to the cytogenetic map. Together, these maps will assist in the assembly of sequence-ready contigs and will aid in the identification of disease loci on chromosome 5 by positional cloning and positional candidate approaches.

Centromere↗
PubMed1997

Common variable immunodeficiency associated with myelocathexis and altered membrane sodium-proton antiport.

Alterations in protein kinase C (PKC) activity have been implied in the pathogenesis of common variable immunodeficiency (CVID). We analyzed amiloride-sensitive red blood cell Na+/H+ exchange (sodium-proton antiport, SPA) and its response to protein kinase stimulation in a patient with CVID. Compared with healthy subjects or patients with sepsis, a unique pattern of SPA activation has been shown. The patient's SPA was decreased and unresponsive to PKC stimulation, whereas stimulation by insulin, a tyrosine kinase activator, restored SPA activity. An alteration of serine-threonine phosphorylation is suggested as a possible mechanism for the immune failure.

Adult↗
PubMed1996

Psychological adjustment among Soviet immigrant physicians: distress and self-assessments of its sources.

The purpose of this study is to examine the psychological distress of Soviet immigrant physicians in Israel and their self-assessed sources of this distress. The subject of this study included 385 (152 men and 233 women) Soviet immigrant physicians who had participated in preparatory licensing courses. The investigation shows that women have higher scores of distress than men in Global Stress Index of the Brief Symptom Inventory and its subscales which reflect anxiety. A comparison of Global Stress Index of the subjects of this study with U.S. and British published non-patient norms shows a significantly higher distress level among the immigrant physicians. Most of the respondents evaluated their psychologic state before immigration to Israel as better (303 or 78.7%). These assessments are found to be directly dependent on the stress load of the respondents at the time of the interview. Perception of the sources of absorption difficulties and distress scores are also found to be in close dependence. The results of the multiple regression analysis indicate that both sex and distress are statistically significant predictors of immigrants' estimation of their difficulties. However, it is the level of distress that has the greatest influence on the assessments of the respondents.

Adaptation, Psychological↗
PubMed1995

Central neurocytoma. A clinicopathological, immunohistochemical and ultrastructural study of 7 cases.

Characterised by distinctive clinicopathological features, the central neurocytoma (CN) is an uncommon and possibly under-recognised primary cerebral neuronal neoplasm. We present clinical and pathological details of seven patients with CN. Histological examination revealed a greater diversity of morphological appearances than is typically described in CN. No anaplastic features were identified. Cellular areas resembling both oligodendroglioma and ependymoma were present in all cases, but each tumour also contained stroma rich areas with hyalinised or aneurysmal vessels. Synaptophysin was expressed by all tumours and probably represents the immunohistochemical marker of choice for identifying CN. Distinguishing ultrastructural features included rounded cell bodies separated by numerous cell processes containing microtubules, pleomorphic neurosecretory granules and occasional synapses. Ki-67 immunostaining revealed a low cell proliferation index in each case. The distinction of CN from other pathological mimics can be reliably made using this multiparametric approach to diagnosis. The generally benign behaviour of CN is confirmed, though there was one patient death in the follow-up period of 10-122 months. Aggressive behaviour in this case was not associated with anaplastic histological features.

Adult↗