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Biomedical subjects

S Tucker

Publications and source records attributed to S Tucker.

At least 73 records · Page 4Linked to original sources
PubMed1988

Effective salvage therapy for lymphoma with cisplatin in combination with high-dose Ara-C and dexamethasone (DHAP).

Ninety patients with progressive recurrent lymphoma were treated with a combination of cisplatin 100 mg/m2 intravenously (IV) by continuous infusion over 24 hours, followed by cytosine arabinoside in two pulses each at a dose of 2 g/m2 given 12 hours apart. Dexamethasone, 40 mg orally or IV, was given on days 1 through 4. Vigorous hydration was reinforced by routine use of mannitol. Treatments were repeated at 3- to 4-week intervals for six to ten courses. Most patients had not achieved complete remission (CR) with prior therapies, which included Adriamycin (all patients) and methotrexate and VP-16 (58 patients). Median patient age was 55 years. Intermediate-grade lymphoma was the most frequent pathologic diagnosis. Seven patients died within two weeks of therapy; of the remaining 83 patients, 28 (34%) or 31% if all patients are considered, achieved CR, and 22 (26.5%) achieved partial remission (PR). Response was evident after the first two cycles of chemotherapy and appeared to be independent of the histopathologic type of lymphoma. To date, only eight of the complete responders have relapsed at a median follow-up of 11 months. The overall 2-year survival in 25%. Further analysis showed that patients with low tumor burden and normal lactic acid dehydrogenase (LDH) had a high CR response rate (67%) and a survival rate of 61% at 2 years. In contrast, patients with both high tumor burden and elevated serum LDH levels had a negligible CR rate, and only 5% are surviving at 1 year. Patients with either high tumor burden with normal LDH or low tumor burden with elevated LDH had an intermediate survival. Myelosuppression-related infection was the most frequent serious complication of this regimen (31%) and the cause of death of ten patients. Acute lysis syndrome was also observed in five patients with high tumor burden and was the cause of death in three of these patients. DHAP has proven to be an effective non-crossresistant regimen for patients with relapsing or refractory lymphoma, particularly for patients who have favorable prognostic characteristics.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1986

Interferon therapy for condylomata acuminata.

Current therapy for condylomata acuminata (genital warts) is not consistently effective. Therefore, we conducted a randomized, double-blind trial to compare interferon alpha-2b with placebo in the treatment of this disorder. Our rationale was that interferon has both antiproliferative and antiviral properties. The placebo or interferon (1 X 10(6) IU) was injected directly into one to three warts three times weekly for three weeks. The injections were well tolerated by both groups of patients. The side effects of fever, chills, myalgia, headache, fatigue, and leukopenia occurred more commonly in the interferon group than in the placebo group, but such effects rarely disrupted daily routines. Only 13 of 296 patients (4 percent) discontinued therapy because of side effects (11 in the interferon group and 2 in the placebo group). Twenty-six other patients were excluded from analysis because of a loss to follow-up or other deviations from protocol, thus leaving 257 patients in the final evaluation. At one week after the completion of therapy, interferon had produced a large and significantly greater reduction in mean wart area (a 62.4 percent decrease), as compared with placebo (a 1.2 percent increase in mean area) (P less than 0.001). At the conclusion of the study (13 weeks after the completion of therapy), the mean wart area was still decreased 39.9 percent below the initial size in the interferon group, whereas it had increased by 46 percent over base-line measurements in the placebo group (P less than 0.001). At the same time, all treated warts had completely cleared in 36 percent of the interferon recipients and in 17 percent of the placebo recipients (P less than 0.001), whereas treated warts progressed in 13 percent of the interferon recipients and in 50 percent of the placebo recipients (P less than 0.001). We conclude that injection of interferon alpha-2b directly into genital warts appears to be an effective and fairly well-tolerated form of therapy.

Adolescent↗
PubMed1986

Endotoxin-induced changes in pulmonary hemodynamics and respiratory mechanics. Role of lipoxygenase and cyclooxygenase products.

We investigated the role of leukotrienes and cyclooxygenase products in endotoxin-induced pulmonary vascular and airway changes. In 11 conscious sheep, measurements of pulmonary vascular resistance (PVR), lung resistance (RL), arterial PO2, leukocyte count (WBC), and plasma thromboxane B2 (TxB2), 6-keto-PgF1 alpha and PgF2 alpha were obtained, before and at predetermined intervals after a 10-min infusion of E. coli endotoxin (0.3 microgram/kg). On a separate occasion, 5 sheep received an infusion of the leukotriene end-organ receptor antagonist FPL-57231 (0.7 to 1 mg/kg/min), before and for as long as 4 h after endotoxin infusion; and 6 sheep received a single injection of the cyclooxygenase inhibitor indomethacin (2 mg/kg) 1 h before endotoxin infusion. Endotoxin caused a biphasic response with an increase in mean PVR and RL to 441 and 353% of baseline, respectively, during the early phase (0 to 1 hr), and lesser increases to 168 and 195% of baseline during the late phase (1.5 to 4 h). These changes were associated with mild hypoxemia, marked leukopenia, and marked increases in plasma TxB2, 6-keto-PgF1 alpha and PgF2 alpha. The FPL-57231 completely blocked the endotoxin-induced changes in PVR, RL, and PaO2 during both phases without preventing the increases in TxB2; however, it partly attenuated the increases in 6-keto-PgF1 alpha and enhanced the generation of PgF2 alpha. Indomethacin, which blocked the endotoxin-induced increases in TxB2, 6-keto-PgF1 alpha, PgF2 alpha, and RL, only partly blocked the increase in PVR during the early phase, followed by an exaggerated increase of PVR during the late phase.(ABSTRACT TRUNCATED AT 250 WORDS)

6-Ketoprostaglandin F1 alpha↗
PubMed1985

Cholinergic agents: antinociception without morphine type dependence in rats.

We have confirmed the work of others showing that loss in body weight is a predictable and consistent sign of opiate withdrawal in rats. Rats that were treated chronically with either oxotremorine or physostigmine displayed no weight loss or other signs of opiate-like withdrawal when the drugs were withdrawn. Furthermore, there was no difference in weight loss between morphine dependent rats substituted with saline and those substituted with either cholinergic drug. However, we did observe an increased mortality among rats substituted with a cholinergic agent compared with saline. Rats infused with a mixture of morphine plus oxotremorine or morphine plus physostigmine showed less weight loss, but not fewer behavioral signs, after the end of the infusion than rats treated only with morphine. It is concluded that the cholinergic agents did not cause a morphine-like physical dependence themselves, but appeared to antagonize to some extent the development or manifestation of opiate dependence.

Analgesics↗
PubMed1985

Methylphenidate in hyperactive children: differential effects of dose on academic, learning, and social behavior.

Methylphenidate (Ritalin) has been shown to have differential effects on hyperactive children's behavior as a function of dose level. In the present investigation, a triple-blind, placebo-control, within-subject (crossover) experimental design was employed in which 12 hyperactive boys between 6 and 10 years received three different dosages of methylphenidate (5, 10, and 15 mg) in a randomly assigned sequence. Dosage effects were assessed on clinic-(PAL--Paired Associates Learning test) and school-(percent on task, teacher ratings, work completion rates, and accuracy) related behaviors. For 10 of the children, classified as responders to medication by the PAL using the criteria of Swanson, Kinsbourne, and colleagues, a series of ANCOVAs with repeated measures showed significant dosage effects on teacher ratings (p less than .01), percent on task (p less than .01), academic accuracy (p less than .05), and assignment completion rates (p less than .05). PAL performance was also significantly enhanced (p less than .01) after optimal dose levels were considered. Subsequent trend analysis showed a significant positive linear relationship between dose and each of the dependent variables. A comparison of fixed-dose and miligram-per-kilogram plots showed that children's performance across the different dosages were clearly individualistic and task-specific, even when similar body weights were compared. The implications of using clinic-based testing to determine optimal medication responsivity were discussed.

Achievement↗
PubMed1985

Remission in skin infiltrate of a patient with mycosis fungoides treated with cyclosporine.

A 57-year-old woman with mycosis fungoides that had failed to respond to cytotoxic chemotherapy was treated with cyclosporine. Mycosis fungoides and Sézary syndrome are disorders of helper T cells. Cyclosporine is a fungal endecapeptide of novel chemical structure that causes preferential inhibition of T helper cells. Because of this in vitro inhibition of T helper cells, we used cyclosporine to treat a patient who had mycosis fungoides that was refractory to cytotoxic combination chemotherapy. With cyclosporine administered initially as an intravenous infusion and orally after 10 days, there was immediate improvement in the patient's symptoms. This subjective improvement was accompanied by a decrease in her skin infiltration, noted on physical examination and microscopically. Despite continued administration of the cyclosporine, symptoms recurred after 3 1/2 months of therapy.

Cyclosporins↗
PubMed1985

Detection of Mycoplasma pneumoniae adhesin (P1) in the nonhemadsorbing population of virulent Mycoplasma pneumoniae.

Mycoplasma pneumoniae organisms possessing a hemadsorbing-negative (HA-) phenotype comprise more than 50% of the population of virulent M. pneumoniae cultures. Monoclonal antibody to P1, the major adhesin of M. pneumoniae reacts with this HA- mycoplasma fraction based upon radioimmunoprecipitation and immunoblotting. Demonstration of P1 in the entire mycoplasma population suggests that topological organization of this adhesin in the membrane or the physiological state of the mycoplasmas may determine hemadsorbing capabilities.

Adhesins, Bacterial↗
PubMed1985

Detection of the major adhesin P1 in triton shells of virulent Mycoplasma pneumoniae.

Filamentous structures designated Triton shells were obtained from virulent Mycoplasma pneumoniae by treatment with Triton X-100. Monoclonal antibodies directed against M. pneumoniae were used in conjunction with radioimmunoprecipitation and Western blotting to detect immunologically reactive polypeptides in Triton shells. The major adhesin, protein P1, was associated with these structures.

Adhesins, Bacterial↗
PubMed1984

Spontaneous remission of multi-system histiocytosis X.

Two infants presented with biopsy-proven histiocytosis X affecting multiple sites. Since neither showed evidence of organ failure or of constitutional upset, no specific therapy was given. In each case there was long-lasting spontaneous regression of disease. Analysis of blood mononuclear cells revealed a raised T4:T8 (helper:suppressor T lymphocyte) ratio at diagnosis but a normal ratio during remission. These observations support the argument that multi-system histiocytosis X, even in infants (Letterer-Siwe disease), is not a malignancy and that an "expectant" treatment policy may be indicated in selected patients.

Biopsy↗
PubMed1983

Leukemic cell colony formation in soft agar by bone marrow cells and peripheral blood cells from untreated acute leukemia patients.

An in vitro culture technique for colony formation of marrow cells and peripheral blood cells from untreated acute leukemia patients and from patients in relapse is described. The colonies from bone marrow cells of an untreated acute myelogenous leukemia (AML) patient were demonstrated to be of leukemic origin by cytogenetic analysis. Cells obtained from colonies of leukemic origin contained the human malignancy-associated nucleolar antigen (HMNA) as detected by indirect immunofluorescence. This nucleolar antigen was not present in marrow or peripheral blood cells or cells from colonies of marrow from hematologically normal individuals. Colonies could be grown from over 70% of the marrow and peripheral blood samples from untreated acute leukemia patients. The median number of colonies obtained was 75 per 10(5) marrow cells from patients with AML. In 1/3 of the cases an increased number of colonies could be grown from marrow cell suspensions kept in liquid culture for 5 days. This is indicative of the proliferative capacity of the colony forming cell population. This assay may be useful for detection of residual clonogenic leukemic cells in marrow and peripheral blood cell suspensions.

Adult↗