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Biomedical subjects

R Zamir

Publications and source records attributed to R Zamir.

At least 19 recordsLinked to original sources
PubMed1998

Changes in physical and chemical constituents of crab meat during storage at refrigerator temperature (7+/-2 degrees C).

The present study was initiated to determine the deteriorative changes occurred in the nutritive quality of crabmeat during storage at refrigerator temperature (7+/-2) for the period of one week. The parameters studied for the assessment of quality are pH, water, total protein and salt soluble protein, TMA-N, TVB-N content. The results indicate a significant increase (p < or = 0.001) in pH, water, TMA. TVB while total protein salt soluble protein, and total lipid contents were significantly decreased (p < or = 0.001) as compared to fresh tissue. Our finding recommended that the quality of crabmeat is acceptable upto one day of storage at refrigerator temperature after that it becomes deteriorated.

Journal Article↗
PubMed1995

Heterosexual and homosexual coercion, sexual orientation and sexual roles in medical students.

Rape has been conceptualized on a dimension of normal male behavior. The Koss and Oros (1982) study used a questionnaire that allowed men to respond only as sexual aggressors of women, and women only as victims of men. Medical students' responses to a modified questionnaire, in which both sexes reported being aggressors and/or victims, revealed that relatively comparable proportions of men and women were victims of coercive experiences: 35% of women and 30% of men experiencing constant physical attempts to have sexual activity. Forms of coercion not involving threat or use of force were more common, more exclusively heterosexual, and carried out by more equivalent percentages of men and women. 15% of women and 12% of men felt initially coerced into sexual activity but then enjoyed it. Threat or use of force to attempt to or to obtain intercourse were employed by 4% of men and 2% of women and experienced by 5% of both sexes. Half the male victims and female aggressors and a quarter of the male aggressors and female victims who reported such coercion stated it was homosexual. The ratio of homosexual/heterosexual feelings reported by male, but not female, students correlated with the degree of the homosexual coercion they both carried out and experienced. The degree of sexual coercion carried out by men and women correlated with their masculine sex role scores, suggesting, if the dimensional concept of rape is valid, that rape is on a continuum with masculine rather than male behaviors.

Adult↗
PubMed1995

Fluorescent in-situ hybridization (FISH) as an aid to marker chromosome identification in prenatal diagnosis.

Five cases of supernumerary marker chromosomes were identified in prenatal diagnosis as derived from chromosomes 18, X, and Y. One unexpected finding was in a case where the PCR was positive for the SRY gene while fluorescence in situ hybridization was positive for two X centromeres. In another case with an X derived supernumerary marker the newborn was phenotypically normal. Two women with fetal mar(18) and mar(Xp) decided to terminate the pregnancy. The fifth pregnancy had a karyotype of 46,XX,-15,+der(15)t(Y:15)(q11,23;p13). A phenotypically normal girl was born at term.

Adult↗
PubMed1995

Sissiness, tomboyism, sex-role, sex identity and orientation.

Masculinity and femininity have been studied by self-ratings in independent areas of research: one investigating personality traits considered masculine (M) or feminine (F); the other, behaviours statistically more common in one than in the other sex (sex-linked behaviours). The two approaches were compared for the first time in the present study of 66 male and 51 female medical students. Consistent with previous findings using the second approach, male but not female subjects' opposite sex-linked "sissy" and "tomboyish" behaviours correlated significantly with their reported ratio of homosexual to heterosexual feelings (Ho/Het). Ho/Het did not correlate with either sex's M and F scores, but high M scores in women correlated strongly with several "tomboyish" behaviours. As "tomboyish" behaviours are shown more strongly by women exposed prenatally to increased levels of opposite sex hormones compared to controls, the findings have implications for the biological theory attributing Ho/Het to such prenatal hormonal exposure.

Adolescent↗
PubMed1993

Development of a scale for measuring impaired control over alcohol consumption: a preliminary report.

Impaired control over drinking has occupied a central place in explanations of alcohol dependence since the late 18th century. Despite this key theoretical role, no instrument has been developed to directly assess the construct. This article describes the development of a three-part Impaired Control Scale (ICS), in which Part 1 measures the degree to which a subject has attempted to exercise control over drinking in the past 6 months; Part 2 measures the degree of success in controlling drinking over the past 6 months; and Part 3 measures the subject's belief in his or her ability to control drinking if it were attempted. Psychometric analysis showed that, despite difficulties reported in the literature, impaired control could be measured in a reliable fashion, with satisfactory discriminant and concurrent validity. Preliminary investigation of the relationship between the ICS and elements of the alcohol dependence syndrome suggests that the construct of impaired control is related to, but may be distinguished from, a general factor of alcohol dependence. While more research is needed to replicate these findings and to examine interrelationships among the various parts of the ICS, the scale may have both theoretical and practical value in research and treatment for alcohol dependence and its related problems.

Adult↗
PubMed1993

Non-sexist Sexual Experiences Survey and Scale of Attraction to Sexual Aggression.

Sixty-six male and 51 female second year medical students anonymously completed the Sexual Experiences Survey (SES) and the Attraction to Sexual Aggression (ASA) Scale, both modified so that women could report behaviours in which they were aggressors, and men, behaviours in which they were victims. Men's aggression scores on the two scales were significantly correlated. As expected, more men than women reported both the likelihood and the experience of being sexual aggressors, although 6% of women reported being so aroused they couldn't stop when their partner didn't want intercourse and 13% of men reported having intercourse against their will. In men sexually coercive behaviours correlated positively with the masculinity scale of the Bem Sex Role Inventory. Fewer female medical students reported experiencing sexually aggressive behaviours compared to US or New Zealand university students; however, the percentage of male students who reported using or threatening to use physical force was in the same range as that of US students. Significant attention to the issue of sexual coercion would appear necessary in the education of medical students.

Adult↗
PubMed1991

Chorionic villus cDNA library displays expression of butyrylcholinesterase: putative genetic disposition for ecological danger.

Gene expression in chorionic villi may be particularly vulnerable to environmental exposure to poisonous substances. To reveal villus gene products which are thus subject to poisoning, molecular cloning was employed. A single sample of apparently normal chorionic villi (approximately 40 mg, from 9 weeks' gestation) was microscopically dissected to ensure purity of fetal tissue. Total RNA was extracted by isothiocyanate and directly employed for reverse transcription. A chorionic villus cDNA library was constructed from this preparation in the phage vector lambda gt10 and contained 60,000 independent recombinants. In the present study, this cDNA library was screened with labelled cDNA probes encoding human butyrylcholinesterase (BCHE) and acetylcholinesterase (ACHE). Nine BCHEcDNA clones were isolated out of 1.6 x 10(6) phages (5.7 x 10(-6) of screened recombinants) and exhibited similar restriction patterns to those observed for BCHEcDNA from other human tissues. In contrast, no ACHEcDNA clones could be found in 4.0 x 10(6) screened phages (less than 2.5 x 10(-6) of recombinants). These findings demonstrate efficient transcription (similar to fetal brain levels) from the BCHE gene but not from the ACHE gene in chorionic villi, and support the notion that BCHE is involved in chorionic villus growth and development.

Acetylcholinesterase↗
PubMed1991

Human acetylcholinesterase and butyrylcholinesterase are encoded by two distinct genes.

1. Various hybridization approaches were employed to investigate structural and chromosomal interrelationships between the human cholinesterase genes CHE and ACHE encoding the polymorphic, closely related, and coordinately regulated enzymes having butyrylcholinesterase (BuChE) and acetylcholinesterase (AChE) activities. 2. Homologous cosmid recombination with a 190-base pair 5' fragment from BuChEcDNA resulted in the isolation of four overlapping cosmid clones, apparently derived from a single gene with several introns. The Cosmid CHEDNA included a 700-base pair fragment known to be expressed at the 3' end of BuChEcDNA from nervous system tumors and which has been mapped by in situ hybridization to the unique 3q26-ter position. In contrast, cosmid CHEDNA did not hybridize with full-length AChEcDNA, proving that the complete CHE gene does not include AChE-encoding sequences either in exons or in its introns. 3. The chromosomal origin of BuChE-encoding sequences was further examined by two unrelated gene mapping approaches. Filter hybridization with DNA from human/hamster hybrid cell lines revealed BuChEcDNA-hybridizing sequences only in cell lines including human chromosome 3. However, three BuChEcDNA-homologous sequences were observed at chromosomal positions 3q21, 3q26-ter, and 16q21 by a highly stringent in situ hybridization protocol, including washes at high temperature and low salt. 4. These findings stress the selectivity of cosmid recombination and chromosome blots, raise the possibility of individual differences in BuChEcDNA-hybridizing sequences, and present an example for a family highly similar proteins encoded by distinct, nonhomologous genes.

Acetylcholinesterase↗
PubMed1990

Expression of alternatively terminated unusual human butyrylcholinesterase messenger RNA transcripts, mapping to chromosome 3q26-ter, in nervous system tumors.

To study the molecular origin of the altered regulation of butyrylcholinesterase (BuChE) in nervous system tumors, BuChE complementary DNA (cDNA) sequences from human glioblastoma and neuroblastoma cDNA libraries were compared with BuChE cDNAs from normal fetal and adult tissues. A single 2.6-kilobase BuChE cDNA sequence was found in all normal tissues, whereas an additional alternatively terminated BuChE cDNA clone was found in both tumor libraries. The tumor-specific cDNA contained a 3',0.7-kilobase nontranslatable extension, as well as several nucleotide alterations in the normal polyadenylation site. Single-base mutations in the coding region of this unusual BuChE cDNA infer two amino acid substitutions: Asp70----Gly and Ser425----Pro. The Asp70----Gly change has recently been implicated with "atypical" BuChE, which is deficient in its capacity to hydrolyze succinylcholine. The 3.6-kilobase mRNA was less abundant in RNA blot hybridization than the 2.6-kilobase mRNA, which is in agreement with the low ratios between the 3.6- and 2.6-kilobase BuChE cDNA clones in glioblastoma and neuroblastoma libraries. Furthermore, size fractionation and microinjection of glioblastoma polyadenylated RNA, followed by enzyme activity and selective inhibition measurements, demonstrated two peaks of functional BuChE mRNA, the heavier one probably reflecting the longer transcripts. Chromosomal mapping of the 0.7-kilobase 3' fragment by in situ hybridization localized it to a unique 3q26-ter position, where we recently found an inheritably amplified "silent" defective CHE gene in a family exposed to the cholinesterase inhibitor methyl parathion. Our findings confirm previous genetic linkage mapping of the functional CHE gene to the 3q26-ter position and demonstrate that extended functional mRNA transcripts encoding a BuChE form with two modified amino acids are produced from this gene in glioblastoma and neuroblastoma cells.

Base Sequence↗
PubMed1990

The expression of HLA class I antigens in germ cell testicular cancer.

The expression of HLA class I antigens in testicular germ cell tumors (TGCTs) was studied by the immunoperoxidase technique. In the normal testicle, the interstitial cells of Leydig as well as most of the germ cells were significantly stained. In typical seminoma, 75% of the tumor cells in stage I and 30% in stage II were stained. In embryonal cell carcinoma, 25% of the cases in stage I and less than 10% of those in stage II were stained. Mature teratoma was stained in most of the cases, whereas in malignant teratoma only 35% of the cases showed some staining of the tumor cells. In mixed tumors each component displayed its characteristic staining pattern. The expression of class I antigens on tumor cells is required for immune recognition and lysis of the tumor by cytotoxic T-cells. The reduced expression of class I antigens that was related to histologic characteristics and stage suggests that some testicular tumors may escape immune surveillance and become biologically more aggressive.

Dysgerminoma↗
PubMed1990

Familial pemphigus vulgaris.

Familial pemphigus vulgaris was found in a Jewish woman and her son who developed the disease within a period of 18 months from one another. HLA typing was performed in the mother and son as well as in the unaffected father and sister. Examination of the HLA antigens in this family indicates that there may be different variants of DR4, DQw3 and that one of them carried by the mother and son as part of the haplotype A30, B18, DR4, DQw3 is associated with pemphigus vulgaris. Our findings are in favor of the concept that particular polymorphic residues of class II major histocompatibility molecules are correlated with disease susceptibility.

Adult↗
PubMed1989

[In-situ hybridization on chorionic villi chromosomes].

Novel techniques for the prenatal diagnosis of inherited defects are currently being developed. The long-range aim is to be able to predict precisely, at an early stage of fetal development, the tendency of the fetus to develop multiple genetic, congenital or acquired diseases. We adapted the technique of gene mapping by in-situ hybridization for use with chromosomes from fetal chorionic villi sampling (CVS). Refined mapping of the genes coding for cholinesterase (CHE) in comparison with the haptoglobin and the transferrin receptor genes on CVS chromosomes Nos. 3 and 16 revealed 3 CHE genes in positions 3q21, 3q26, and 16q12. In view of genetic linkage data, at least 2 of these appear to be potentially active. These findings demonstrate that genes, for which molecularly cloned DNA probes are available, may be localized on CVS chromosomes by comparing their localization with that of known genes after in-situ hybridization. The implications for prenatal diagnosis are promising.

Cholinesterases↗
PubMed1989

De novo amplification within a "silent" human cholinesterase gene in a family subjected to prolonged exposure to organophosphorous insecticides.

A 100-fold DNA amplification in the CHE gene, coding for serum butyrylcholinesterase (BtChoEase), was found in a farmer expressing the "silent" CHE phenotype. Individuals homozygous for this gene display a defective serum BtChoEase and are particularly vulnerable to poisoning by agricultural organophosphorous insecticides, to which all members of this family had long been exposed. DNA blot hybridization with regional BtChoEase cDNA probes suggested that the amplification was most intense in regions encoding central sequences within BtChoEase cDNA, whereas distal sequences were amplified to a much lower extent. This is in agreement with the "onion skin" model, based on amplification of genes in cultured cells and primary tumors. The amplification was absent in the grandparents but present at the same extent in one of their sons and in a grandson, with similar DNA blot hybridization patterns. In situ hybridization experiments localized the amplified sequences to the long arm of chromosome 3, close to the site where we previously mapped the CHE gene. Altogether, these observations suggest that the initial amplification event occurred early in embryogenesis, spermatogenesis, or oogenesis, where the CHE gene is intensely active and where cholinergic functioning was indicated to be physiologically necessary. Our findings demonstrate a de novo amplification in apparently healthy individuals within an autosomal gene producing a target protein to an inhibitor. Its occurrence in two generations from a family under prolonged exposure to parathion indicates that organophosphorous poisons may be implicated in previously unforeseen long-term ecological effects.

Butyrylcholinesterase↗
PubMed1989

Gene mapping on chorionic villi chromosomes by hybridization in situ: localization of cholinesterase cDNA binding sites to chromosomes 3q21, 3q26-ter and 16q21.

To adapt the in-situ hybridization approach for use in very early fetal development, comparative in-situ hybridization was initiated on chromosomes from chorionic villus sampling (CVS). An additional aim was to refine the localization of the chromosomal sites binding butyrylcholinesterase (BuChE) cDNA by mapping them in parallel to previously mapped genes of close locations. BuChEcDNA was previously found to bind to the long arms of lymphocyte chromosomes 3 and 16, with a wide distribution of grains suggesting two separate sites on chromosome 3. When labelled with 35S and hybridized with CVS chromosomes, BuChEcDNA was bound to three distinct sites, designated CHEL1, CHEL2 and CHEL3. These peaked at 3q21, 3q26-ter and 16q21 respectively. Parallel hybridization with the cDNA encoding transferrin receptor (TFRC) refined its localization to 3q29, in agreement with previously published results and in a distal position to CHEL2, whereas haptoglobin cDNA (HPcDNA) was correctly mapped at 16q24, distal to CHEL3. In view of the published genetic linkage between the CHEL1 locus and the transferrin TF gene on 3q25, this study suggests that one of the three sites carrying BuChE-coding sequences, namely CHEL2, harbours the functional CHEL1 gene. Thus, in-situ hybridization provides a rapid and precise method for the localization of genes on CVS chromosomes, in comparison with known DNA markers.

Binding Sites↗
PubMed1989

Chorionic villi sampling for early prenatal diagnosis: an option for the Jewish orthodox community.

The Jewish religion permits abortion up to 40 days after conception. To accommodate the Jewish orthodox community, prenatal diagnosis in the eighth gestational week may be a feasible goal with clear benefits. We present our experience with chorionic villus sampling (CVS), wherein out of 144 patients requesting CVS, 125 were found to be suitable for the procedure. Excluding patients with fundal placenta and cervical or uterine myoma, chorionic sampling was successfully performed on 102 out of 106 patients (96.2%) and a chromosome result was available for 98 of those patients (96%). Fetal losses, within 14 days following procedure, were 2 out of 125 (1.6%). No complications were encountered following the procedure. The cytogenetic analysis was improved by culturing CVS fragments for 48 h, after which clearer banding patterns could be observed. One of the CVS preparations, from a 7.2/7-week-old embryo was successfully examined. Short-term (6 days) cultures were used as an additional method for chromosome analysis, to extend and confirm results obtained by the direct method.

Abortion, Spontaneous↗