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Biomedical subjects

M Kotler

Publications and source records attributed to M Kotler.

At least 145 records · Page 8Linked to original sources
PubMed1987

Genetic alterations of integrated avian sarcoma virus DNA sequences in transformed rat cells.

Clones and subclones of Schmidt-Ruppin-RSV-D-(SRD-) infected rat cells that were isolated in soft agar have shown differences in their morphology. Some of the subclones were round or spindle-shaped cells with lower anchorage dependence and high growth rate, while others were more fibroblast-like and failed to overgrow one another. In correlation to their morphology, subclones with high degree of phenotypic transformation contained amplified amounts of full length proviral DNA or proviral fragments. The amplification affected the proviral DNA elements together with host cellular DNA sequences. We have also shown a relationship between the copy number of the proviruses in the cells, the level of expression of viral RNA, and between those two parameters and the various degrees of phenotypic transformation.

Animals↗
PubMed1987

Posttraumatic stress disorder in Israeli combat veterans. Effect of phenelzine treatment.

Twenty-five Israeli combat veterans fulfilling DSM-III criteria for posttraumatic stress disorder (PTSD) participated in an open, prospective trial of phenelzine sulfate administration (median daily dose, 60 mg; range, 30 to 90 mg); three patients withdrew early due to side effects. Treatment was continued for at least four weeks in 22 cases and thereafter for as long as it was felt to be of benefit. Therapeutic efficacy was rated using a new PTSD scale, the Hamilton Depression Scale, and the Hamilton Anxiety Scale administered at four weekly intervals. Six patients completed four to eight weeks of phenelzine treatment; seven patients, nine to 13 weeks; and nine patients, 14 to 18 weeks. Comparison of mean prediscontinuation scores with pretreatment ratings showed, at best, only small (23% to 38%) differences (on the PTSD and Hamilton Anxiety scales) in the group treated for nine to 13 weeks. Two patients with a concurrent diagnosis of panic disorder and two with a concurrent diagnosis of dysthymic disorder were the most improved symptomatically but fell short of clinically significant remission. Although statistically significant improvement was observed on seven of the 12 items of the PTSD scale, sleep disturbance was the only symptom showing a clinically impressive change. These results only partially support previous positive reports of phenelzine treatment of PTSD.

Adult↗
PubMed1987

A two year follow-up of somatic complaints among Israeli combat stress reaction casualties.

The relationships of somatic complaints and health related habits to combat stress reaction and post-traumatic stress disorder were assessed one and two years after the 1982 Lebanon War. The sample consisted of 285 combat stress reaction Israeli casualties and 198 comparable controls. Results showed that higher rates of somatic complaints were reported by both combat stress reaction and post-traumatic stress disorder casualties at the two points in time. Theoretical and methodological implications were discussed.

Adolescent↗
PubMed1986

[The post-traumatic syndrome: 6 months after the trauma].

In 61 persons examined six months after their evacuation for an acute combat syndrome, the clinical wide range of which is well known, the presence of a clear psychiatric anamnesis (only noticed in the fourth part of the cases) or of a significant immediate psychic reaction, had no influence on the clinical picture of the post-traumatic syndrome. The depressive affect emerged from unvarying current features. Three quarters of the patients still offered such a very homogeneous "block". This short duration study only concerned people who went on living in a familial or social environment, but whose problem of disablement had not yet been settled, consequently excluding the most serious and mildest cases. However, concerning combat stress or traumas in civil surroundings, the data gathered show the necessity of an early and active therapeutic approach.

Adult↗
PubMed1985

Newly developed microcarrier culturing systems--an overview.

Microcarrier (MC) culturing systems are widely employed for the production of biological products required for human and veterinary uses and serve as a tool for basic research in cell biology. Three types of MCs were developed by our group: cellulose, polyacrylamide and polystyrene based MCs. These newly developed MCs were used for the propagation of primary cells, cells from a human diploid cell strain and cells from established cell lines, for the production of biological products (various viruses, mouse interferon and carcinoembryonic antigen) as well as for studying cell differentiation. Basic questions regarding the effect of the chemical nature of MCs on cell attachment, spreading and growth were investigated throughout the development of these MCs.

Acrylic Resins↗
PubMed1985

Ion exchange capacity of DEAE microcarriers determined the growth pattern of cells in culture.

Transformed embryonic avian and mammalian cells, as well as cells from established cell lines grow as a monolayer on DEAE-cellulose based microcarriers (MC): the DE-52 and DE-53 MC. Normal, non-transformed, embryonic avian and mammalian cells do not grow on DE-52 MC (having an exchange capacity of 1 meq/g dry material) but grow well on DE-53 MC (having an exchange capacity of 2 meq/g dry material). On DE-53 MC embryonic non-transformed cells grow in multilayers, while embryonic viral-transformed cells and cells from established cell lines grow in a monolayer form. Possible explanations for the differences in cell growth on various MC and variation in the mode of growth in monolayer vs multilayer are discussed. These differences may serve as a valuable tool for separation and distinction between normal and transformed cells. In addition, the described novel MC culturing system provides a support for tridimensional growth on which cell growth mimics the in vivo growth conditions. Therefore, this system is suitable for the study of cell recognition, cell to cell connection and cell orientation.

Animals↗
PubMed1984

High- and low-leukemogenic variants of the radiation leukemia virus (RadLV): immunogenic, suppressive and genetic properties in relation to leukemogenic activity.

C57BL/6 (B6) mice inoculated with the highly leukemogenic variant of the radiation leukemia virus (A-RadLV) develop suppressor cells capable of abrogating potential anti-tumor immunity in vitro and in vivo. Inoculation of B6 animals with the low-leukemogenic D-RadLV variant does not result in suppressor cell generation but induces antitumor reactive lymphocytes. A-RadLV and D-RadLV are not leukemogenic in BALB/c or (B6 X BALB/c)F1(F1) mice, and reactive but not suppressor lymphocytes could be demonstrated in F1 animals inoculated with either virus. Infectivity assays and fingerprint analysis revealed that A-RadLV and D-RadLV contain viruses with N and B tropism. In addition, thymoma cells induced by A-RadLV produced another virus with a fingerprint pattern containing X-MuLV elements. The possible implications of the different virus types on the immunogenic and leukemogenic properties of the RadLV variants are discussed.

Animals↗
PubMed1984

RNAase-sensitive DNA-dependent DNA polymerase from rat cells transformed by avian sarcoma virus.

An RNAase-sensitive DNA polymerase from rat cells transformed by avian sarcoma virus has been characterized. The enzyme requires RNA for its activity, as shown by its sensitivity to RNAase with endogenous as well as exogenous DNA templates. This sensitivity is maintained after its purification by sucrose gradients and ion exchange columns. A molecular weight of about 100 000 has been estimated. This DNA polymerase requires high salt concentration for its activity, is resistant to high concentrations of phosphonoacetic acid (400 micrograms/ml), is partially inhibited by 5 mM N-ethylmaleimide, and is completely inhibited by 0.3 mM parahydroxymercuribenzoate.

Animals↗
PubMed1984

Acquisition of host cell genetic information by avian sarcoma virus rescued from rat cells transformed by B77 virus.

The properties of avian sarcoma virus B77 grown in chick cells were compared with those of virus obtained by fusion of rat cells transformed by B77 virus ( RB77 cells) with chick cells ( FB77 virus). Differences in the B77 and FB77 viral genomes were demonstrated by the fingerprint technique. The rescued FB77 virus contained sequences homologous to the normal cell genome. These results suggest that the rescued FB77 virus is a recombinant between B77 virus and rat genomic elements. The RNAs from B77 and FB77 viruses were found to have similar molecular weights. The migration rates of the structural proteins and the large glycoprotein (gp 85) in polyacrylamide gels were the same for the B77 and FB77 viruses, but the small glycoprotein (gp) of the FB77 virus was found to be slightly larger than the gp37 of the B77 virus.

Animals↗
PubMed1984

Demonstration and characterization of virus released by murine B cell leukemia cells (BCL1).

LPS-stimulated leukemia cells derived from BALB/c mice bearing transplantable B-lymphocytic leukemia (BCL1) which arose spontaneously in a female BALB/c mouse, contained viral particles as suggested by electron microscopy as well as by tissue cultures using the XC assay. Some cell free extracts prepared from BCL1 cells were capable of transforming normal B-lymphocytes when inoculated into untreated syngeneic recipients. Cytogenetic analysis of spleen cells obtained from a splenomegalic male mouse neonatally inoculated with cell-free extract indicated that the tumor cells had a male karyotype with 42 chromosomes as compared to 37 chromosomes and a female karyotype in original BCL1 cells, thus excluding the possibility of tumor propagation by transplantation of intact BCL1 cells. These findings suggest viral involvement in the etiology of BCL1.

Animals↗
PubMed1984

Role of substrata in determining the growth topology of transformed and nontransformed cells in culture.

Cylindrical DEAE cellulose anion exchangers (DE-53), generally used for chromatography, were found suitable as a substratum for cultivating cells. Embryonic avian and mammalian cells cultured on DE-53 microcarriers (MC) grow in multilayers, while the same embryonic cells when transformed by avian sarcoma virus (ASV) grow in monolayers. These patterns of cell growth differ from those of normal and transformed cells grown on conventional glass or plastic Petri dishes, or on beaded MC. Cells derived from established cell lines such as BHK, HeLa, L-929, MDCK, and VERO grow in monolayer on these MC. A human adenocarcinoma cell line is the only exception growing in a multilayer form. These results indicate that the ability of cultured cells to grow in multilayers, is determined not only by their state of transformation but also by the properties of the support on which they are cultured.

Adenocarcinoma↗
PubMed1984

Persistent and acute central nervous system infections are caused by Theiler's murine encephalomyelitis viruses which differ in RNA composition but code for only slightly different proteins.

The RNA and proteins for four representatives of the two subgroups of Theiler's murine encephalomyelitis viruses were studied. The large RNase T1-resistant oligonucleotides, when mapped along the RNA molecules, were found to be differently distributed in the two subgroups. Replicative form RNAs of two representatives were partially denatured, and the denaturation maps obtained were found to be similar but not identical. In addition, the analysis of the tryptic maps of the capsid proteins of all four isolates revealed that only small differences in the peptide map patterns exist among these viruses. The correlation of these findings with the pathogenicity of Theiler's viruses is discussed.

Animals↗
PubMed1983

Synaptogenesis and myelination in dissociated cerebral microcarrier cell cultures.

A new approach for cultivating dissociated cerebral neurons is described. It is based on a rapid attachment of neurons to the DEAE-cellulose cylindrical MC and their subsequent interconnection to form cell-MC conglomerates. Intensive fiber growth followed by synaptogenesis and progressive myelin formation are indicative of optimal conditions of nutrition and oxygenation.

Acetylcholinesterase↗
PubMed1983

GDVII and DA isolates of Theiler's virus: proteins attached to the 5' end of the RNA are bound covalently to the same nucleotides.

GDVII and DA picornaviruses, which represent two biologically distinct subgroups of Theiler's murine encephalomyelitis viruses, were analyzed to detect the presence of a RNA-linked protein, VPg. It was found that the single-stranded RNA genomes isolated from the virions of both viruses contain a protein of approximately 7,000 daltons, which is covalently linked to the 5' end of the RNA. Like in other picornaviruses (e.g., poliovirus and encephalomyocarditis virus), the terminal nucleotide adjacent to the protein was found to be pUp. The possibility that differently charged VPg species exist is also mentioned.

Base Sequence↗
PubMed1983

Mammalian cell propagation on derivatized polyacrylamide microcarriers.

A working system for studying the effects of factors involved in the chemical nature of microcarrier on cell attachment, spreading and growth, was established. The system is based on polyacrylamide beads, prepared by the emulsion polymerization technique. Sieved beads of desirable mean diameter were derivatized to generate controlled amounts of primary and tertiary amino groups. These microcarriers were used for propagation of vive different cell strains: BHK, MDCK, CEF, MRC-5 and FS. It was found that BHK cells attach and spread significantly faster on primary amino derivatized beads than those with tertiary amino groups, and at a lower degree of charging. As a result of introducing hydrophobicity to the side chain carrying the primary amino group, higher kinetic rates of BHK cell attachment were obtained. Optimal cell growth of all the tested cells was recorded for the butyl and the hexyl side chains. On the other hand the introduction of hydrophobicity into the polymeric backbone of the microcarrier led to lower cell yields. Primary amino derivatized MCs with an optimal degree of hydrophobicity city exhibit a higher cell yield of MDCK cells (with pronounced epithelial morphology), as compared to the tertiary amino derivatized MCs. CEF and FS cells (with pronounced fibroblast morphology) attained cell yields comparable to those obtained with the tertiary amino derivatized MCs. The diaminohexane derivatized polyacrylamide microcarriers seem to be a potential alternative for the commonly used tertiary amino derivatized micro-carriers.

Acrylic Resins↗