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Biomedical subjects

S Schwartz

Publications and source records attributed to S Schwartz.

At least 253 records · Page 14Linked to original sources
PubMed1996

PTSD symptoms and comorbid mental disorders in Israeli war veterans.

BACKGROUND: The purpose of this study was to investigate patterns of mental disorders co-morbid with PTSD symptoms in young Israeli men exposed to combat. METHOD: Six hundred and seventeen subjects were selected via a general population sample and evaluated in a two-phase case-identification procedure, culminating in a modified SADS-L interview, administered by psychiatrists. RESULTS: Major depressive disorder (OR = 3.2), substance use disorders (OR = 1.9) and personality disorders (OR = 3.0) occurred more frequently in men reporting symptoms of PTSD than in men who had been under fire who did not report symptoms. With the possible exception of personality disorders, comorbid disorders did not constitute risk factors for PTSD. Comorbid PTSD and RDC disorders were associated with increased help-seeking. CONCLUSIONS: The results suggest similar rates and types of PTSD comorbidity in Israeli war veterans as in veterans in the US assessed in general population studies, and are consistent with shared risk factors for PTSD and comorbid disorders.

Adult↗
PubMed1996

Comparison of the effects of estrogen alone and estrogen plus androgen on biochemical markers of bone formation and resorption in postmenopausal women.

The present study was undertaken to determine whether the addition of an androgen to estrogen therapy in postmenopausal women would alter the skeletal response as determined by measurements of markers of bone formation and resorption. Postmenopausal women were treated for 9 weeks with either a combination of 1.25 mg esterified estrogen and 2.5 mg methyltestosterone (E+A) or 1.25 mg conjugated equine estrogen (CEE). Both groups showed a similar decrease in urinary excretion of the bone resorption markers, deoxypyridinoline, pyridinoline, and hydroxyproline. Patients treated with CEE showed decreases in the serum markers of bone formation, bone-specific alkaline phosphatase, osteocalcin, and C-terminal procollagen peptide. In contrast, subjects treated with E+A showed increases in these markers of bone formation. CEE increased, and E+A decreased serum levels of sex hormone-binding globulin as well as triglycerides and high density lipoprotein levels. Only CEE significantly reduced low density lipoproteins. Both regimens were effective in reducing postmenopausal somatic symptoms, but only E+A had a significant effect on psychological symptoms. We conclude that short term administration of androgen with estrogen may reverse the inhibitory effects of estrogen on bone formation. Long term studies are needed to determine the relative benefits and risks of the combination of estrogen and androgen and whether this results in greater increases in bone mass and strength.

Aged↗
PubMed1996

Molecular definition of breakpoints associated with human Xq isochromosomes: implications for mechanisms of formation.

To test the centromere misdivision model of isochromosome formation, we have defined the breakpoints of cytogenetically monocentric and dicentric Xq isochromosomes (i(Xq)) from Turner syndrome probands, using FISH with cosmids and YACs derived from a contig spanning proximal Xp. Seven different pericentromeric breakpoints were identified, with 10 of 11 of the i(Xq)s containing varying amounts of material from Xp. Only one of the eight cytogenetically monocentric i(Xq)s demonstrated a single alpha-satellite (DXZ1) signal, consistent with classical models involving centromere misdivision. The remaining seven were inconsistent with such a model and had breakpoints that spanned proximal Xp11.21: one was between DXZ1 and the most proximal marker, ZXDA; one occurred between the duplicated genes, ZXDA and ZXDB; two were approximately 2 Mb from DXZ1; two were adjacent to ALAS2 located 3.5 Mb from DXZ1; and the largest had a breakpoint just distal to DXS1013E, indicating the inclusion of 8 Mb of Xp DNA between centromeres. The three cytologically dicentric i(Xq)s had breakpoints distal to DXS423E in Xp11.22 and therefore contained > or = 12 Mb of DNA between centromeres. These data demonstrate that the majority of breakpoints resulting in i(Xq) formation are in band Xp11.2 and not in the centromere itself. Therefore, we hypothesize that the predominant mechanism of i(Xq) formation involves sequences in the proximal short arm that are prone to breakage and reunion events between sister chromatids or homologous X chromosomes.

Cell Line↗
PubMed1996

Evidence for structural heterogeneity from molecular cytogenetic analysis of dicentric Robertsonian translocations.

Most Robertsonian translocations are dicentric, suggesting that the location of chromosomal breaks leading to their formation occur in the acrocentric short arm. Previous cytogenetic and molecular cytogenetic studies have shown that few Robertsonian translocations retain ribosomal genes or beta-satellite DNA. Breakpoints in satellite III DNA, specifically between two chromosome 14-specific subfamilies, pTRS-47 and pTRS-63, have been indicated for most of the dicentric 14q21q and 13q14q translocations that have been studied. We have analyzed the structure of 36 dicentric translocations, using several repetitive DNA probes that localize to the acrocentric short arm. The majority of the translocations retained satellite III DNA, while others proved variable in structure. Of 10 14q21q translocations analyzed, satellite III DNA was undetected in 1; 6 retained one satellite III DNA subfamily, pTRS-47; and 3 appeared to contain two 14-specific satellite III DNA sub-families, pTRS-47 and pTRS-63. In 10/11 translocations involving chromosome 15, the presence of satellite III DNA was observed. Our results show that various regions of the acrocentric short arm, and, particularly, satellite III DNA sequences, are involved in the formation of Robertsonian translocations.

Centromere↗
PubMed1996

Origins of heterogeneous ovarian carcinomas. A molecular cytogenetic analysis of histologically benign, low malignant potential, and fully malignant components.

It is unclear whether ovarian carcinomas develop from malignant transformation of benign precursors or whether they arise de novo. Thus, histologically benign or low malignant potential components found in heterogeneous ovarian carcinomas may be remnants of pre-existing lesions that progressed to malignancy or, alternatively, elements that arose independently (de novo). In a third possible interpretation, they represent areas of malignant epithelium that matured. We evaluated clonal relationships of histological components in 10 heterogeneous ovarian carcinomas using fluorescence in situ hybridization and confocal microscopy. Detailed analysis of aneuploidy for chromosomes 8, 12, and 17 on intact paraffin sections revealed that two tumors were aneuploid in all components, two lacked abnormalities in benign-appearing components, and one lacked aneuploidy in both histologically benign and low malignant potential components. Histological appearance was significantly related to aneuploidy (P < 0.05). The distribution of aneuploidy among tumor components strongly supports the tumor progression theory and demonstrates that the de novo hypothesis is highly unlikely (P < 0.001). Results also indicate that benign-appearing components in heterogeneous ovarian carcinomas do not represent maturation of malignant tissue and suggest that some benign tumors that become cancerous may have genetic aberrations that predispose them to malignant transformation.

Aneuploidy↗
PubMed1995

Human papillomavirus type 16 capsid proteins produced from recombinant Semliki Forest virus assemble into virus-like particles.

Several neutralizing sites of the human papillomavirus (HPV) capsid are known to be critically dependent on the conformation of the capsid. However, efficient production of HPV16 capsids in mammalian cells has been difficult, possibly because the HPV genome contains negative regulatory elements. To circumvent these problems, we cloned the HPV16 L1 and L2 genes from a healthy HPV16-infected woman into a Semliki Forest virus based expression vector (P. Liljeström and H. Garoff, Biotechnology 9, 1356-1361, 1991). Recombinant HPV16 L1- or L2-producing Semliki Forest virus was generated and used for infection of mammalian cells. The HPV16 L1 and L2 proteins were efficiently expressed and the majority of the L1 protein self assembled into virus-like particles (VLPs). Coexpression of L1 and L2 resulted in incorporation of L2 into the VLPs. The particles had a density of approximately 1.3 g/ml as determined by density gradient centrifugation. Transmission electron microscopy revealed that the particles had a morphology similar to native virions. The HPV16 VLPs produced by the Semliki Forest virus expression system may be useful as a conformationally correctly assembled target for studies of HPV attachment, assembly, serology, or vaccination.

Animals↗
PubMed1995

Application of FISH to complex chromosomal rearrangements associated with chronic myelogenous leukemia.

Identification of complex chromosomal rearrangements can be difficult, due either to the limited number and sometimes poor quality of metaphases in bone marrow preparations or to the nature of the rearrangements. Fluorescence in situ hybridization (FISH) using chromosome-specific DNA libraries in conjunction with a cosmid probe for the c-ABL oncogene was performed to substantiate the preliminary G-banded karyotypes of six patients with chronic myelogenous leukemia (CML). Our results indicate that FISH is sufficiently sensitive to detect complex and subtle rearrangements, even in bone marrow preparations with suboptimal metaphases, and can provide valuable corroborative information.

Bone Marrow↗
PubMed1995

Uniparental isodisomy 13 in a normal female due to transmission of a maternal t(13q13q).

Chromosomes from a normal 23-year-old, primigravid woman were examined at 10 weeks of gestation because of her mother's history: 8 miscarriages and two liveborn infants (the proposita and a brother who died at 3 days with multiple anomalies). Karyotypes of the proposita and her normal mother were 45,XX,t(13q13q). No evidence of mosaicism was encountered. When the proposita inherited the t(13q13q), she received two copies of 13q from her mother. Moreover, she and her mother shared the same homozygous pattern of alleles from 7 highly polymorphic microsatellite repeats localized along 13q. No evidence of paternal markers from 13 was detected, although biparental inheritance was demonstrated with DNA markers from chromosomes 2 and 17. Cytogenetic and molecular findings indicated that the proposita's chromosomal complement included mUPD 13q. The proposita's normal phenotype suggested that no maternally imprinted genes map to 13q.

Abortion, Habitual↗
PubMed1995

Parental origin of De Novo chromosome 9 deletions in del(9p) syndrome.

Parental origin of de novo deletions in the short arm of chromosome 9 in patients with a clinical diagnosis of del(9p) syndrome was assessed in 13 patients using polymerase chain reaction (PCR) analysis of highly polymorphic dinucleotide repeat microsatellite markers located in the putative deleted region. The deletion was found to be of paternal origin in 9 cases and of maternal origin in the remaining 4 cases, suggesting that the molecular event resulting in the deletion occurs in both male and female gametogenesis and that genomic imprinting does not appear to play a role in the pathogenesis of del(9p) syndrome.

Child↗
PubMed1995

Overexpression of human immunodeficiency virus type 1 protease increases intracellular cleavage of Gag and reduces virus infectivity.

Here we have investigated if human immunodeficiency virus type 1 (HIV-1) protease expressed in trans can interfere with production of infectious HIV-1 particles. Protease produced from a Tat and Rev inducible expression plasmid specifically cleaved HIV-1 p55Gag in a dose-dependent manner. Coexpression of protease and an infectious HIV-1 proviral clone resulted in increased intracellular cleavage of p55Gag. As a consequence, virus production and virus infectivity was significantly reduced. These results suggest that overexpression of HIV-1 protease in HIV-1-infected cells is a powerful way to inhibit production of infectious virions.

Base Sequence↗
PubMed1995

Enhancement of HIV-1 proteinase activity by HIV-1 reverse transcriptase.

HIV-1 reverse transcriptase (RT) was found to increase the activity of HIV-1 proteinase in vitro and in eukaryotic cells. The effect of RT on proteinase activity was dose-dependent and independent of pH or salt concentration. The cleavage of sequences corresponding to all the naturally occurring cleavage sites that could be tested in vitro was enhanced. The effect of RT on cleavage was greatest at the cleavage site between RT and integrase. The enhancement of viral proteinase activity by the virus RT may contribute to regulation of the order and/or efficiency of cleavage at different sites during virus replication and maturation.

Base Sequence↗
PubMed1995

Trisomy 7p resulting from isochromosome formation and whole-arm translocation.

A newborn boy with a large anterior fontanel, minor facial anomalies, postaxial polydactyly, patent ductus arteriosus, and developmental delay had trisomy of 7p due to an i(7p) and a concomitant t(2;7) (q37.3;q11.1). Significant enlargement of the fontanel is the most characteristic finding in most patients with duplications involving 7p15-pter. Asynchrony in fore- and hindbrain and hemisphere formation leading to brain asymmetry and various defects in the posterior fossa are typical of infants with duplications of 7p11-p12. A variety of heart defects has also been found in more than 50% of patients with duplication of 7p segments. Isochromosome formation accompanied by whole-arm translocation, resulting in uniparental isodisomy for the involved segment, is an extremely rare cause leading to partial trisomies. Although it is not clear whether isochromosome formation precedes the whole-arm translocation or follows it, the secondary rearrangement may have adaptive significance.

Abnormalities, Multiple↗