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Biomedical subjects

A Borenstein

Publications and source records attributed to A Borenstein.

27 records · Page 2Linked to original sources
PubMed1989

[Resection of invasive orbital tumors and reconstruction with temporalis muscle flap].

3 patients with invasive basal cell carcinoma of the skin which necessitated orbital exenteration are reported. In all 3 treatment was delayed, primary therapy was inadequate and the tumor had reached massive size. Excision of the orbital contents is a radical, mutilating procedure, but in advanced cases of malignant orbital tumors it offers the only chance for survival. The temporalis muscle flap is adaptable, well supplied with blood, and contains a large mass of tissue. Its utilization provides a simple, uncomplicated and effective technique for orbital reconstruction following massive resection. It gives a relatively effective result which is usually acceptable to the patient.

Aged↗
PubMed1989

[Sex reassignment surgery in a trans-sexual].

Trans-sexualism is a psychiatric disorder characterized by the conviction that one's gender identity does not conform to one's biological sex. The current Diagnostic and Statistical Manual of Mental Disorders gives 5 diagnostic criteria for trans-sexualism which most health care professionals accept. Although many trans-sexuals derive some gratification from assuming roles appropriate to their desired gender, a substantial number are convinced that only sexual transformation can bring meaningful relief of their feelings of despair. Approximately 2/3 of trans-sexuals who undergo sex reassignment procedures are improved at follow-up. A relatively advanced age and secondary trans-sexualism (transvestites and effeminate homosexuals) are risk factors for poor prognosis in those requesting sex reassignment. In recent decades the demand for sex reassignment has increased, as have the number and variety of psychological, hormonal and surgical treatments proposed. The operative procedures currently employed for sex reassignment give reasonably good esthetic and functional results, and in 1986 the Israel Ministry of Health permitted its government hospitals to perform them. A 23-year-old male trans-sexual is reported who underwent successful surgery for sex change and now, 1 year later, is satisfied with the result.

Adult↗
PubMed1986

Pre-CFU-f: young-type stromal stem cells in murine bone marrow following administration of DNA inhibitors.

Occurrence of young-type stromal stem cells (defined here as "pre-CFU-f") in murine bone marrow is reported in this study. Two consecutive intraperitoneal (i.p.) cytosine arabinoside (ara-C) injections were administered to C57B1 mice (2 X 200 mg/kg at 6-h intervals). Two days later the bone marrow was collected and assayed for colony-forming units-fibroblastoid (defined here as "CFU-f"). In additional experiments, ara-C-treated marrow was exposed in vitro to hydroxyurea (HU; "hydroxyurea killing test"), prior to plating, to establish the cycling state of stromal stem cells. In separate cultures of ara-C-treated marrow, replating of adherent cells was carried out up to quaternary sub-cultures. The results indicate ara-C-treated marrow produces approximately 20% "huge" fibroblastoid colonies (approximately 5 mm diameter versus 0.5-2 mm normal size); most stromal stem cells producing huge colonies are cycling cells; and adherent cells from primary ara-C-treated marrow cultures replated to secondary cultures produce adherent layers with double the number of cells than in the control secondary cultures. We conclude that the ara-C-treated murine bone marrow contains certain young-type cycling stromal stem cells which we refer to as pre-CFU-f. These stem cells produce huge fibroblastoid colonies in culture, indicating that they probably go through more cell cycles than CFU-f during the culture period. Alternatively, pre-CFU-f may have a higher self-replicative capacity than CFU-f.

Animals↗
PubMed1985

Effects of chemotherapy on bone marrow stroma in mice with acute myelogenous leukemia. Correlation with CFU-C and CFU-D.

This study describes changes in bone marrow stroma in murine acute myelogenous leukemia (AML). The AML was induced in C57B1 mice by intravenous (i.v.) transfusion of C4198 myelogenous leukemic cells. In untreated leukemic mice, the colony-forming unit fibroblasts (CFU-F) were severely inhibited. In leukemic mice treated by three chemotherapy protocols of cytosine-arabinoside (Ara-C) and adriamycin there was a 200% increase in the life span as compared to untreated leukemic animals and marked reduction of marrow leukemic load. In these mice the stromal inhibition was temporarily relieved, expressed by peaks of CFU-F2-3 days following each protocol. In between the peaks, CFU-F decreased to subnormal levels, remaining low to the end of the disease. In normal mice administered a similar chemotherapy regimen, there were peaks of CFU-F activation after each protocol and normal levels in between the peaks. Granulocyte/macrophage progenitors (CFU-C) of leukemic-treated and normal-treated mice showed increased levels following each chemotherapy protocol. Whereas CFU-C decreased below normal levels in leukemic mice towards the end of the disease, the level of these progenitors remained high in normal mice receiving Ara-C and adriamycin. Colony-forming units in diffusion chamber (CFU-D) showed mild fluctuations in both leukemic and normal mice receiving three protocols of Ara-C and adriamycin. It is possible that despite treatment, the bone marrow stroma in leukemia becomes irreversibly deficient towards the end of the disease and cannot support the residual normal hematopoiesis.

Animals↗
PubMed1984

Bone marrow stromal deficiency in acute myeloid leukemia in mice.

A study of bone marrow stroma in acute myeloid leukemia (AML) in mice was carried out. AML was induced in C57B1 mice by i.v. inoculation of the C1498 cell line. There was a direct correlation between the marrow leukemic load and the degree of marrow stromal deficiency. This was expressed by reduced in vitro fibroblastoid colony formation. In co-cultures of normal mouse bone marrow and leukemic cells, and also in cultures of normal marrow with added conditioned medium (CM) of leukemic cells, marked inhibition of fibroblast-colony-forming units (CFU-F) from normal marrow was observed. In additional experiments, leukemic mice were treated with two consecutive injections of cytosine arabinoside (Ara-C) (2 X 200mg/kg) and sacrificed 48 h later. Bone marrow samples of treated animals formed in vitro an increased number of fibroblastoid colonies despite relatively high levels of marrow leukemia. It is concluded that: (a) there is a direct correlation between the incidence of marrow leukemic cells and the degree of stromal deficiency; (b) leukemic cells produce in vitro--and probably in vivo CFU-F inhibitory factors and (c) administration of restricted doses of cytosine arabinoside to leukemic mice reduces the marrow leukemic cell content to some extent and increases the capacity of CFU-F to form fibroblastoid colonies in vitro.

Animals↗
PubMed1983

Incidence and characteristics of colony-forming units fibroblasts (CFU-F) in the bone marrow of weanling mice treated with cytosine arabinoside and phenylhydrazine: correlation with CFU-S, progenitors of diffusion-chamber colonies (CFU-D), and CFU-C.

A study of murine adherent marrow cells (AMC) under conditions of high and low concentrations of hematopoietic stem cells and progenitors was carried out. In one group of weanling mice, decreased marrow cellularity and increased concentrations of CFU-S, CFU-D, and CFU-C were observed two days after administration of two consecutive intraperitoneal (i.p.) cytosine arabinoside (Ara-C) injections (2 x 200 ng/kg, at 6 h interval). Fibroblast colony-forming units (CFU-F) of this marrow were studied. In a second group of mice, which were given three i.p. phenylhydrazine (PHZ) injections (3 x 60 mg/kg on days 0, 1, and 3), CFU-S and CFU-C levels were unchanged or lowered 6 days after the start of PHZ administration. In these animals, however, the number of CFU-D was four times higher than in controls. The study of CFU-F in experiments of groups 1 and 2 indicated a high concentration of these progenitors in group 1 and lower concentration in group 2. Furthermore, fibroblastoid colonies produced in vitro by CFU-F of Ara-C-treated marrow were significantly larger than colonies from control marrow, and they markedly inhibited G/M colonies in split-phase agar cultures. By contrast, fibroblastoid colonies produced by PHZ-treated marrow were of regular size and did not inhibit G/M colonies from test bone marrow.

Animals↗