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Biomedical subjects

R D Levin

Publications and source records attributed to R D Levin.

9 recordsLinked to original sources
PubMed1991

Phase I clinical trial with floxuridine and high-dose continuous infusion of leucovorin calcium.

Sixty-two patients with metastatic disease were treated with continuous infusion folinic acid (leucovorin calcium; Lv) and 2-deoxy-5-fluorouridine (floxuridine; FUDR). Lv was given by constant intravenous (IV) infusion at 500 mg/m2/d, days 1 to 6, while FUDR was given by IV push, days 2 to 6, at 3:00 PM daily with doses ranging from 294 to 1,214 mg/m2/d. This program was well tolerated with dose-limiting toxicities of diarrhea and stomatitis, while hematologic toxicity was minimal. Eighty-two percent of the assessable patients (46 of 56) had failed at least one chemotherapy regimen. One complete remission lasting 9 months and 10 partial remissions ranging from 5 to 10 months were observed in this heavily pretreated patient population for an overall response rate of 20%. These data suggest that the combination therapy with Lv and FUDR may have clinical use. Because of differing patient sensitivity to this drug combination, the recommended dose of FUDR for the initial therapy cycle is 500 mg/m2/d, days 2 to 6, with subsequent escalation to 900 mg/m2/d in those patients without extreme sensitivity. Phase II studies are now in progress with these doses.

Adult↗
PubMed1991

[Intracavernous pharmacotherapy for treatment and evaluation of impotence].

Impotence affects about 10% of all men. During the past decade it has been treated with self-injection of vasoactive drugs into the erectile tissue. In 1982 Virag reported experience with intracavernous injection of papaverine. Since then other vasoactive drugs, such as prostaglandin E1 (PGE1), have been used successfully, and self-injection has been advised. Between 1987-1989 we evaluated 550 patients with erectile dysfunction and 95 aged 21-79, mean 53.7, were found suitable for this treatment, of whom 80 were entered into an autoinjection protocol, of 74 were treated with a mixture of papaverine and regitine and 6 with PGE1. The volume of the injections ranged from 0.1 to 1.0 ml, and erections lasted from 15 minutes to 8 hours. 72% of the patients continued autoinjection during a mean follow-up of 9.9 months and were satisfied with the results. There were 5 cases of corporal fibrosis, and 3 cases had prolonged erections, usually after the papaverine test. The method is simple and inexpensive, and allows many impotent men to resume sexual life. It is a good alternative to the insertion of a penile prosthesis.

Adult↗
PubMed1986

Relative efficacy and toxicity of netilmicin and tobramycin in oncology patients.

We prospectively compared the efficacy and safety of netilmicin sulfate or tobramycin sulfate in conjunction with piperacillin sodium in 118 immunocompromised patients with presumed severe infections. The two treatment regimens were equally efficacious. Nephrotoxicity occurred in a similar proportion in patients treated with netilmicin and tobramycin (17% vs 11%). Ototoxicity occurred in four (9.5%) of 42 netilmicin and piperacillin and in 12 (22%) of 54 tobramycin and piperacillin-treated patients. Of those evaluated with posttherapy audiograms, three of four netilmicin and piperacillin-treated patients had auditory thresholds return to baseline compared with one of nine tobramycin and piperacillin-treated patients. The number of greater than or equal to 15-dB increases in auditory threshold as a proportion of total greater than or equal to 15-dB changes (increases and decreases) was significantly lower in netilmicin and piperacillin- vs tobramycin and piperacillin-treated patients (18 of 78 vs 67 of 115). We conclude that aminoglycoside-associated ototoxicity was less severe and more often reversible with netilmicin than with tobramycin.

Adult↗
PubMed1985

Suppression of B-lymphocyte function by T-lymphocytes in patients with advanced lung cancer.

The ability of B-lymphocytes to produce immunoglobulins in response to pokeweek mitogen stimulation was studied in 21 untreated stage III lung cancer patients by culture of their mononuclear cells in vitro. The number of immunoglobulin-producing cells was significantly lower in 20 of the 21 patients when compared to responses shown by normal control subjects. In contrast, the proliferative responses of many of the patients were within the normal range. When the T-lymphocytes of these patients were irradiated with 1,250 rad to eliminate the suppressor T-cell activity and then cultured with autologous B-cells, the number of immunoglobulin-producing cells was enhanced to the normal range in 7 of the 18 patients. These results indicate that B-cell function is impaired in most patients with advanced lung cancer. They also suggest that, in addition to suppression by radiosensitive suppressor T-cells, other mechanisms are involved in the observed B-cell functional abnormality.

Adult↗
PubMed1979

Fibrinolysis in familial pulmonary hypertension.

Although an autosomal dominant mode of inheritance has been documented for many cases of primary pulmonary hypertension, the pathogenesis of the disease remains unclear. A report of abnormal fibrinolysis in familial pulmonary hypertension has raised the possibility that the pathogenesis may be related to an impaired ability to lyse recurrent pulmonary microemboli. Primary pulmonary hypertension was diagnosed in three of ten members of a kindred. The pattern of inheritance was compatible with an autosomal dominant gene. Eight members of the kindred were available for study, one of whom has primary pulmonary hypertension. The results of coagulation studies, caseinolytic determinations of plasminogen and antiplasmin, and fibrinolytic titers of antiurokinase did not differ significantly from those of the control group. These findings suggest that a deficient fibrinolytic system is not the cause of primary pulmonary hypertension, although differences in methodology may explain our inability to demonstrate abnormal circulating fibrinolysis in this kindred.

Blood Coagulation↗
PubMed1978

Changes in platelet function during hemodialysis.

Platelet function was studied in 34 patients during 74 hemodialyses by means of a Cordis-Dow hollow fiber hemodialyzer (CDAK-4) with anticoagulation by porcine mucosal heparin. The mean arterial platelet levels fell 11% from predialysis values and remained stable throughout a 5 hr hemodialysis session. After 30 min of dialysis, the platelet concentration in afferent and efferent limbs of the dialyzer were similar, although retention of leukocytes was apparent. As measured by platelet aggregometry, heparin was clearly shown to potentiate the extent of aggregation induced by low concentrations of ADP. Platelets of the dialyzer afferent limb were less aggregable than normal and resistant to aggregation induced by submaximal concentrations of ADP or epinephrine. Platelets of the dialyzer efferent limb were aggregable only after excessive stimuli of 50 micrometer ADP or 10 micrometer epinephrine. These findings suggest that direct contact between dialyzer fibers and platelets or rheological effects led to impaired platelet function but that most platelets are not irreversibly injured.

Blood Cell Count↗
PubMed1977

Return of function in the thrombosed kidney after transplantation.

The incidence of intraglomerular thrombi in renal allografts and factors regulating their resolution were studied. A case report is presented in which resolution of intraglomerular thrombi is documented. In addition, 17 transplanted patients with renal biopsies were serially studied. Intraglomerular thrombi were found in 4 of 8 specimens taken 1 h after reanastamosis, all from donors with a terminal course involving prolonged hypotension. Glomerular fibrinolytic activity was markedly diminished in 4 of 11 patients' subsequent biopsy specimens; all taken during acute rejection. Resolution of thrombi was documented when signs of rejection were absent.

Adult↗