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Biomedical subjects

A Aviram

Publications and source records attributed to A Aviram.

At least 19 recordsLinked to original sources

From aviation to medicine: applying concepts of aviation safety to risk management in ambulatory care.

The development of a medical risk management programme based on the aviation safety approach and its implementation in a large ambulatory healthcare organisation is described. The following key safety principles were applied: (1). errors inevitably occur and usually derive from faulty system design, not from negligence; (2). accident prevention should be an ongoing process based on open and full reporting; (3). major accidents are only the "tip of the iceberg" of processes that indicate possibilities for organisational learning. Reporting physicians were granted immunity, which encouraged open reporting of errors. A telephone "hotline" served the medical staff for direct reporting and receipt of emotional support and medical guidance. Any adverse event which had learning potential was debriefed, while focusing on the human cause of error within a systemic context. Specific recommendations were formulated to rectify processes conducive to error when failures were identified. During the first 5 years of implementation, the aviation safety concept and tools were successfully adapted to ambulatory care, fostering a culture of greater concern for patient safety through risk management while providing support to the medical staff.

Ambulatory Care↗

Karyotype of the abortus in recurrent miscarriage.

OBJECTIVE: To assess the chromosomal aberrations in the abortus in recurrent miscarriage and the live birth rate after a euploid or aneuploid miscarriage. DESIGN: Retrospective analysis. SETTING: Tertiary referral unit in university hospital. PATIENT(S): One hundred sixty-seven patients with 3 to 16 miscarriages before 20 weeks. INTERVENTION(S): Material collected at curettage from 167 abortuses was analyzed by standard G-banding techniques. MAIN OUTCOME MEASURE(S): The incidence of aberrations and the outcome of the subsequent pregnancy were assessed according to the embryonic karyotype. RESULT(S): In this study 125 specimens were successfully karyotyped. Of these, 29% (36 of 125) had chromosome aberrations; 94% of the aberrations were aneuploidy, and 6% were structural. The most prevalent anomalies were chromosome 16, 18, and 21 trisomies, triploidy, and monosomy X. After an aneuploid miscarriage, there was a 68% subsequent live birth rate (13 of 19) compared to the 41% (16 of 39) rate after a euploid abortion. CONCLUSION(S): The low (29%) incidence of aberrations indicates that alternative mechanisms may be responsible for the majority of recurrent miscarriages. These figures provide a basis for assessing the efficacy of therapy for recurrent miscarriage. If further studies confirm that patients with karyotypically abnormal fetuses have a good prognosis, an informed decision can be made as to whether further investigations and treatment should be undertaken.

Abortion, Habitual↗

Doxorubicin and a butyric acid derivative effectively reduce levels of BCL-2 protein in the cells of chronic lymphocytic leukemia patient.

B-chronic lymphocytic leukemia (B-CLL) is a disease caused primarily by defects in the apoptosis mechanism. AN-9, a butyric acid (BA) derivative, is a potent differentiating and an anti-cancer drug that induces apoptosis in HL-60 cells. Herein we show the affect of AN-9, alone and in combination with doxorubicin, on cell cultures from B-CLL patients. Cells from 17 patients were cultured and tested for viability, apoptosis, bcl-2 and bax protein expression. Exposure of B-CLL cell cultures to AN-9 was accompanied by apoptosis and a marked viability loss (up to 46%, p=0.0017). AN-9 reduced up to 51% (p=0.0017) the levels of bcl-2 in 57% of the cultures that express bcl-2. The combination of low concentrations of AN-9 and doxorubicin more than additively enhanced apoptosis and reduced bcl-2 levels in B-CLL cultures which were resistant to AN-9. AN-9 enhanced bax expression up to 58%(p=0.008) in cultures from 53% of the patients, but had no effect on bax levels when combined with doxorubicin. In conclusion, AN-9 alone reduced bcl-2 and enhanced bax expression in cultures from B-CLL patients, and the reduction of bcl-2 levels in combination with doxorubicin was greater than additive. These results may be beneficial in possible future combination therapy with AN-9 in B-CLL.

Antineoplastic Combined Chemotherapy Protocols↗

Febrile convulsions, ataxia, developmental delay, and obesity: a new syndrome?

We describe the association of recurrent complicated febrile convulsions, developmental delay, ataxia, and obesity in three unrelated girls. The three girls, aged 3 to 4 years, were all born to healthy, nonconsanguineous parents and have normal siblings. Their birth weight was appropriate for gestational age. They are not dysmorphic and have normal head circumference. Development is delayed; they all walked with an ataxic gait after the age of 2 years and started speaking at 3 years. Their growth charts are remarkably alike: they initially had a normal growth curve and around 24 months of age started to gain weight excessively. They all continue to suffer from complicated febrile seizures, which started before 12 months of age, and are resistant to prophylactic anticonvulsants. Metabolic evaluation is normal. They have normal magnetic resonance images and electroencephalograms. Fragile X and Prader-Willi syndromes were ruled out. We suggest that this is a new mental retardation syndrome that should be considered in children with recurrent febrile convulsions, developmental delay, and obesity. In a recent study, mutations in the beta4 calcium channel were identified in the mutant epileptic mouse that presents with epilepsy, mental retardation, and ataxia. We hypothesize that a calcium channel gene may be involved in this syndrome.

Child, Preschool↗

The association between sporadic somatic parental aneuploidy and chromosomally abnormal placentae in habitual abortions.

To determine whether there is a correlation between the proportion of aneuploid cells in peripheral lymphocytes and the karyotype of the abortus in recurrent miscarriage. 40 couples with recurrent miscarriage and their abortuses were cytogenetically analyzed according to the analysis of 60 cells per proband. Women were divided into two groups according to the proportion of chromosomally abnormal cells in the abortus. Chromosomal analysis was performed using G-banding with trypsin-Giemsa in parental peripheral blood and in the abortus. 20 of the 40 abortuses had a chromosomally abberant karyotype. 65% of parents aborting an embryo with with an increased proportion of chromosomally aberrant cells, had more than 10% aneuploid cells in their peripheral lymphocytes. However, only 12.5% of couples aborting an embryo with chromosomally normal cells had increased rates of aneuploidy. An increased proportion of aneuploid cells was found in the lymphocytes of recurrently aborting couples who repeatedly abort chromosomally abnormal fetuses. Mitotic instability in the lymphocytes may indicate a predisposition to instability at meiosis leading to a chromosomal abberations in the embryo and its subsequent abortion.

Abortion, Habitual↗

Electronics using hybrid-molecular and mono-molecular devices.

The semiconductor industry has seen a remarkable miniaturization trend, driven by many scientific and technological innovations. But if this trend is to continue, and provide ever faster and cheaper computers, the size of microelectronic circuit components will soon need to reach the scale of atoms or molecules--a goal that will require conceptually new device structures. The idea that a few molecules, or even a single molecule, could be embedded between electrodes and perform the basic functions of digital electronics--rectification, amplification and storage--was first put forward in the mid-1970s. The concept is now realized for individual components, but the economic fabrication of complete circuits at the molecular level remains challenging because of the difficulty of connecting molecules to one another. A possible solution to this problem is 'mono-molecular' electronics, in which a single molecule will integrate the elementary functions and interconnections required for computation.

Journal Article↗

Uptake of pivaloyloxymethyl butyrate into leukemic cells and its intracellular esterase-catalyzed hydrolysis.

UNLABELLED: Pivaloyloxymethyl butyrate (AN-9), a butyric acid (BA) prodrug, exhibited low toxicity and significant anticancer activity in vitro and in vivo. The purpose of this study was to elucidate the basis for AN-9 increased anticancer activity compared to BA, by studying the uptake of BA and AN-9 into the cells. METHODS: The uptake rate and level of [14C]-AN-9 and [14C]-BA, labeled on the carboxylic moiety of BA, into HL-60 and MEL leukemic cell lines was measured. The cells were filtered and the retained radioactivity was determined. The dependence of the uptake on the activity of cellular esterases and membrane fluidity was investigated. RESULTS: The uptake level in cells incubated with [14C]-AN-9 increased rapidly, peaked after 30 min in MEL and 1 h in HL-60 cells, and declined thereafter. This decline could be attributed to the hydrolysis of AN-9 by cellular esterases and catabolism of the released BA to CO2. In cells pretreated with an esterase inhibitor and incubated with [14C]-AN-9, the reduction of radioactivity was less precipitous. In cells exposed to [14C]-BA, the intracellular radioactivity level was low and unaffected by treatment with an esterase inhibitor. The uptake of [14C]-AN-9 decreased significantly at 4 degrees C compared to that at 37 degrees C. CONCLUSION: The higher potency of AN-9 compared to BA could be at least partially attributed to the more rapid uptake of the lipophilic AN-9 and the release of BA in the cells.

Animals↗

Comparative genomic hybridization in inherited and sporadic ovarian tumors in Israel.

To gain an understanding of the molecular mechanisms of ovarian cancer, we analyzed 16 ovarian tumors from Jewish Israeli patients by comparative genomic hybridization: 12 invasive epithelial tumors (including three BRCA1 and one BRCA2 mutation carriers), 2 primary peritoneal carcinomatosis, 1 pseudomyxoma peritoneii tumor, and 1 sertoli cell tumor. We similarly analyzed 1 normal ovary from a BRCA1 mutation carrier, and 3 metastases. The most common abnormalities in epithelial tumors were amplification of 8q22.1-ter (8/12, 66.6%), 1q22-32.1 (5/12, 41.6%), 3q, 10p (4/12, 33.3% for each), and deletions of 9q (5/12, 41.6%) and 16q21-24 (4/12, 33.3%). All 3 BRCA1 mutation carriers and 2 of 8 sporadic cases displayed 9q deletion, and 2 of 3 BRCA1 mutation carriers, but none of the sporadic cases, had deletion of chromosome 19. The range of genetic changes in primary peritoneal tumors and epithelial ovarian cancers was similar, though the mean number of alterations in the former was less (3.5/tumor versus 8/tumor). Our preliminary results may indicate that inherited predisposition to ovarian cancer possibly entails preferential somatic deletions of chromosomes 9 and 19.

Aged↗

Expression of bcl-2 and bax in cells isolated from B-chronic lymphocytic leukemia patients at different stages of the disease.

B-Chronic lymphocytic leukemia (B-CLL) is an example of a human malignancy caused by alterations in the pathways of programmed cell death. In this disease the anti-apoptotic protein, bcl-2, is overexpressed and may lead to the prolonged survival of a malignant CLL clone. In the present study we examined the expression of bcl-2 and bax, which has an antagonistic role against the function of bcl-2, in cells from CLL patients at different stages of the disease, by immunoblot analysis. A direct association between the stage of the disease and the level of bcl-2 in the patients' cells was observed. At stages A and B, 33% and 29% of patients, respectively, expressed high levels of bcl-2, as opposed to 80% of patients at stage C (p= 0.019). Bax level was not significantly associated with the stage of the disease, although patients at stage C had higher levels of bax. In this study we found a trend of association between bcl-2 and bax levels. Analysis including all patients revealed that 65% of the patients who expressed high levels of bcl-2 had high levels of bax (p = 0.058). Of patients in stage C, 45% expressed high levels of both bcl-2 and bax while 50% and 42% of patients at stages A and B had low levels of both proteins.

Adult↗

Significance of BCR-ABL transcripts in bone marrow aspirates of Philadelphia-negative essential thrombocythemia patients.

Philadelphia-negative (Ph-neg) essential thrombocythemia (ET), polycythemia vera (PV) and idiopathic myelofibrosis (IMF) form a syndrome of related chronic myeloproliferative disorders (MPD) characterized by expansion of one or more of the hematopoietic progenitors. Based on our previous finding of BCR-ABL transcripts in bone marrow aspirates of 12/25 Ph-neg ET patients, we have expanded our study up to 40 patients. Here we describe the rational for performing this study and report 19 of 40 patients who have BCR-ABL transcripts in their BM, 11 of them carry b3a2 and 8 carry b2a2. The two groups, BCR-ABL positive and negative, were completely identical with regard to clinical characteristics and laboratory data. We also report preliminary results of our attempt to examine concordance or discordance of BCR-ABL expression in the peripheral blood and bone marrow of Ph-neg ET patients.

Adult↗

Concurrent use of flow cytometry and fluorescence in-situ hybridization techniques for detecting faulty meiosis in a human sperm sample.

Routine semen analysis in an infertile patient revealed severe teratospermia associated with malformation of head and tail in 100% of the sperm cells. Flow cytometry and fluorescence in-situ hybridization (FISH) were shown to supplement routine semen analysis by providing information on the sperm chromatin. Using flow cytometry, propidium iodide-stained spermatozoa from the same sperm sample were compared with a normal reference pool, and with human lymphocytes. The results point to a population of diploid sperm cells rather than to mature haploid spermatozoa. Numerical chromosomal abnormalities of the spermatozoa were subsequently evaluated using FISH. A total of 1000 sperm cells were scored for X and Y chromosomes, and an additional 1128 sperm cells for chromosome 18. Aneuploidy of chromosomes X and Y was revealed in 96.9% of the cells and of chromosome 18 in 90.3% of the cells. Non-disjunction of chromosome X and Y in meiosis I and II occurred in 54.8 and 2.7% of the sperm cells respectively. Non-disjunction in both meiosis I and II occurred in 39.4% of the sperm cells. A normal haploid pattern for chromosomes X and Y was observed in only 3.1%, and for chromosome 18 in 9.7%, of the cells. Using three colour FISH for the sex chromosomes and for chromosome 18, diploidy was demonstrated in 19.4% of 500 sperm cells and aneuploidy in virtually all sperm cells (99.2%). The use of flow cytometry and FISH in cases where genetic and developmental chromatin abnormalities are suspected is a valuable adjunct to other available techniques, and can guide the clinicians to decide which samples are unsuitable for intracytoplasmic injection.

Adult↗

Comparative genomic hybridization analysis of nonfunctioning pituitary tumors.

Clinically nonfunctioning pituitary adenomas constitute about one third of pituitary neoplasms and are considered monoclonal tumors. The molecular mechanisms of tumorigenesis in these neoplasms are poorly understood, as evidenced by the paucity of reported somatic genetic alterations. Furthermore, the somatic mutations detected to date were primarily ascribed to candidate genes or chromosomal regions: gsp, ras, p53 mutations, and allelic losses of 11q and 13q. To gain insight into which chromosomal regions bear genes involved in nonfunctioning pituitary tumorigenesis, we examined 23 such tumors by comparative genomic hybridization. Four tumors showed no genetic abnormality, and the rest (17 of 23, 74%) exhibited at least one chromosomal region of abnormality. Gains and losses affected all chromosomes (except for chromosome 14). Notably, 8 of 23 tumors (34.7%) displayed sex chromosome and chromosome 18 aberrations (amplifications or deletions). Nonrandom DNA amplification of sub-chromosomal regions on 4q, 5q (5q13-->5q23), 9p (9p21-->9pter), 13q (13q21-->13q32), and 17q were detected in 10-30% of the tumors. Noteworthy, no tumor displayed deletion of 11q, the MEN1 gene locus. These findings suggest that genes localized to previously undescribed chromosomal regions play a role in the tumorigenesis of nonfunctioning pituitary adenomas.

Adenoma↗

Velocardiofacial manifestations and microdeletions in schizophrenic inpatients.

Velocardiofacial syndrome (VCFS) is associated with an increased frequency of schizophrenia and other types of psychiatric morbidity. In this study, we tried to identify a subgroup of schizophrenic patients with deletions in the VCFS region of the long arm of chromosome 22. For that purpose, we screened the records of two major general hospitals for patients with abnormalities characteristic of VCFS, such as cardiac anomalies and cleft palate, and cross-checked the data with the register of psychiatric hospitalizations in four psychiatric hospitals. Of the 24 patients that qualified, only seven patients could be studied. An additional eight schizophrenic inpatients were ascertained clinically, based on a working VCFS Clinical Scale. FISH studies and molecular analyses, using polymorphic markers from the VCFS region, documented hemizygosity of 22q11 in three out of 15 patients (20.0%). Increased awareness of psychiatrists to signs of VCFS among patients with psychiatric illnesses is encouraged, in order to direct molecular studies effectively. In order to cut down the cost of testing, we suggest screening suspected patients with a single marker, such as D22S941, and to study further only those who have a single electrophoretic band.

Abnormalities, Multiple↗

BCR-ABL transcripts in bone marrow aspirates of Philadelphia-negative essential thrombocytopenia patients: clinical presentation.

One of the diagnostic criteria of essential thrombocythemia (ET) is the absence of the Philadelphia chromosome (Ph-neg). On the molecular level, Ph-neg ET patients may carry BCR-ABL transcript. The natural history of BCR-ABL positive Ph-neg ET patients is undetermined. We examined the BCR-ABL status by reverse transcriptase two-step nested polymerase chain reaction in bone marrow aspirates of 25 Ph-neg ET patients. We found 12 BCR-ABL positive and 13 BCR-ABL negative patients in the study group. The comparison showed that the two groups had similar clinical and laboratory characteristics, except for a significant increased patients' age and decreased polymorphonuclear cell count in the BCR-ABL positive group. During a median follow-up of 20 and 22.5 months for the BCR-ABL negative and positive groups, respectively, there was neither blastic transformation nor unrelated death in both groups. We conclude that it is important to look for BCR-ABL transcript in Ph-neg ET patients and to follow them closely to investigate the nature of this translocation in this group of patients.

Adult↗

Effect of the cytostatic butyric acid pro-drug, pivaloyloxymethyl butyrate, on the tumorigenicity of cancer cells.

Previously we have shown that pivaloyloxymethyl butyrate (AN-9), a pro-drug of butyric acid (BA), is a differentiation-inducing agent in a variety of cells. In this report, we demonstrate that AN-9 is a cytostatic but not cytotoxic agent in a myelomonocytic cell line (WEHI); thus, the cells were growth-arrested and differentiated. These late changes in the cells were preceded by changes in the expression of the early regulatory genes, c-myc and c-jun. Although initiation of all these events had already occurred after 1 h exposure to AN-9, the tumorigenicity of these cells tested in Balb/c mice was not affected. A marked reduction in the tumorigenicity of AN-9-treated cells was observed after 4 h of exposure. Exposure of the highly metastatic subclone of Lewis lung carcinoma (3LLD122) to AN-9 resulted in a very pronounced effect on the tumorigenicity of these cells tested in C57BL mice. Unlike WEHI cells, the tumorigenicity of 3LLD122 was almost completely diminished after 1 h of exposure. In both cell types a 10-fold higher concentration of BA did not affect the tumorigenicity of the cells as did AN-9.

Animals↗

Inositol treatment of autism.

Recent studies suggest that serotonin reuptake inhibitors are helpful in at least some symptoms of autism. Inositol is a precursor of the second messenger for some serotonin receptors, and has been reported effective in depression, panic disorder and obsessive-compulsive disorder. However a controlled double-blind crossover trial of inositol 200 mg/kg per day showed no benefit on 9 children with autism. Since biochemical studies could evaluate inositol in children already receiving serotonin reuptake inhibitors.

Autistic Disorder↗

Comparison between the effect of butyric acid and its prodrug pivaloyloxymethylbutyrate on histones hyperacetylation in an HL-60 leukemic cell line.

A butyric acid pro-drug, pivaloyloxymethyl butyrate, AN-9, developed in our laboratory, was previously shown to act as a differentiation-inducing and an anti-cancer agent. In this study we have shown that both AN-9 and butyric acid caused a transient hyperacetylation of histones, which returned to basal levels after 6 and 12 hr, respectively. This activity precedes the induction of differentiation elicited by both agents. AN-9 induced acetylation of histones at a concentration one order of magnitude lower than butyric acid. Pre-treatment of the cells with esterase(s) inhibitors diminished the ability of AN-9 to inhibit proliferation and induce differentiation. The above suggests that the intracellular release of butyric acid fragment, from the pro-drug, is catalyzed by cellular esterase(s).

Acetylation↗

Novel anticancer prodrugs of butyric acid. 2.

The antitumor activity of novel prodrugs butyric acid was examined. The in vitro effect of the compounds on induction of cytodifferentiation and on inhibition of proliferation and clonogenicity showed that (pivaloyloxy)methyl butyrate (1a) (labeled AN-9) was the most active agent. SAR's suggested that its activity stemmed from hydrolytically released butyric acid. In vivo, 1a displayed antitumor activity in B16F0 melanoma primary cancer model, manifested by a significant increase in the life span of the treated animals. Murine lung tumor burden, induced by injection of the highly metastatic melanoma cells (B16F10.9), was decreased by 1a. It also displayed a significant therapeutic activity against spontaneous metastases which were induced by 3LL Lewis lung carcinoma cells. Moreover, 1a has the advantage of low toxicity, with an acute LD50 = 1.36 +/- 0.1 g/kg (n = 5). These results suggest that 1a is a potential antineoplastic agent.

Animals↗