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Biomedical subjects

R Fenstermaker

Publications and source records attributed to R Fenstermaker.

4 recordsLinked to original sources
PubMed1998

Severe cerebellar swelling and thrombotic thrombocytopenic purpura associated with FK506.

Two patients with CsA-associated neurotoxicity developed severe cerebellar swelling and thrombotic thrombocytopenic purpura after switching to FK506 and high-dose corticosteroids. The prodrome of CsA-associated neurotoxicity, TTP and hypertension while receiving FK506, and high-dose corticosteroids could all be implicated in the development of this syndrome. Close monitoring of patients receiving FK506 and high-dose corticosteroids, for the development of TTP is warranted. Early radiological examination should also be considered in such patients to allow early surgical intervention.

Adult↗
PubMed1997

Phenotypic and functional analysis of Fas (CD95) expression in primary central nervous system lymphoma of patients with acquired immunodeficiency syndrome.

The poor prognosis associated with patients afflicted with the acquired immunodeficiency syndrome and primary central nervous system lymphoma (AIDS-PCNSL) is due in part to the intrinsic resistance of this Epstein-Barr virus (EBV)-associated tumor to conventional antineoplastic therapy. Fas (CD95) is a transmembrane protein receptor that transmits an intracellular signal leading to rapid programmed cell death following ligation with its natural ligand or anti-Fas antibodies. Fas expression and function were assessed in AIDS-PCNSL biopsy samples and in EBV+ human B-cell tumors that spontaneously developed in severe combined immune deficient (SCID) mice engrafted with human lymphocytes (hu-PBL-SCID mice). All tumors samples showed high-density surface expression of Fas by flow cytometry or immunohistochemical staining. Cells from two AIDS-PCNSL biopsy samples that did not express pan B-cell markers did not express Fas antigen. All tumors examined were susceptible to Fas-mediated apoptosis, as measured by standard assays for endonucleolytic cleavage of DNA. The response to Fas-mediated apoptosis was dependent on log-fold increases in the concentration of immobilized anti-Fas antibody, but could also be induced with a mobilized anti-Fas antibody. No evidence for intrinsic resistance to Fas-mediated apoptosis (ie, secreted or truncated forms of Fas) could be shown. Radiation-induced apoptosis of neoplastic EBV+ B cells was enhanced by activation of Fas, and prolonged exposure to interleukin-2 increased both Fas expression and Fas-induced apoptosis. As the normal brain parenchyma appears to have either low-density or absent expression of Fas, and antineoplastic therapy can be selectively delivered to the CNS with little systemic toxicity, local delivery of Fas-activating molecules could prove to be a useful component in the multimodal treatment of AIDS-PCNSL.

Animals↗
PubMed1987

Value of growth hormone dynamics and somatomedin C (insulin-like growth factor I) levels in predicting the long-term benefit after transsphenoidal surgery for acromegaly.

Transsphenoidal microsurgery has been shown to be effective in the management of human growth hormone (hGH)-secreting pituitary adenomas. We have previously demonstrated the usefulness of hGH dynamic testing (oral glucose tolerance, insulin hypoglycemia, and thyrotropin-releasing hormone stimulation test) in evaluating the completeness of removal of the adenomas. In patients with acromegaly, serum insulin-like growth factor I (IGF-I) levels are known to correlate with the activity of the disease. We studied the dynamics of hGH secretion in 43 patients with hGH-secreting adenomas 2 to 3 months after surgery. In addition, serum IGF-I levels were recently measured in frozen sera obtained from these patients at the time of dynamic testing. Of the 43 patients undergoing surgery, 19 had normal basal hGH levels as well as dynamics (group I). Two additional patients had low or undetectable hGH levels and were hypopituitary (group II). These 21 patients were considered cured and had no evidence for recurrence of their disease during a mean follow-up period of 97 months. Serum IGF-I levels were normal in 19 (group I) and low in the remaining two patients (group II). Nine additional patients had normal basal hGH levels but abnormal dynamics of secretion (group III). Serum IGF-I levels were normal postoperatively in seven of eight patients tested in this group. During the follow-up period in these nine patients (group III), biochemical and clinical recurrence of acromegaly developed in five. The remaining 13 patients had persistent elevation of basal hGH levels, and all samples tested (n = 8) had elevated IGF-I levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Acromegaly↗