Biomedical subjects

R F Branda

Publications and source records attributed to R F Branda.

At least 37 records · Page 2Linked to original sources

PubMed1991

Factors influencing mutation at the hprt locus in T-lymphocytes: women treated for breast cancer.

Forty-nine women with breast cancer were enrolled in a prospective, longitudinal study of the genetic damage caused by treatment. Assays of mutant frequency at the hprt locus in peripheral blood lymphocytes were performed at approximately 6-month intervals for 2 years. Treatment consisted of surgery alone or additional tamoxifen, radiotherapy, or chemotherapy in various combinations. At 6 months, there was an elevation of mean mutant frequency compared to initial values (P = 0.004) which persisted for as many as 2 years. A significant elevation at 6 months occurred only in the group of women who received combination chemotherapy (P = 0.005). Within this group, 5 of 15 patients had striking elevations of mutant frequency following chemotherapy (greater than 3 SD). Three of these 5 women had serum folate levels in the deficient range, while only one of 9 patients with lesser responses to chemotherapy were folate deficient. The change in mutant frequency after chemotherapy was inversely related to serum folate levels (P = 0.05) and to the number of years of smoking cigarettes (P = 0.01). We conclude that of the various modalities used to treat breast cancer, only chemotherapy was accompanied by a high risk of somatic mutation. A subset of patients manifested substantial increases in mutant frequency, often in association with low serum folate levels.

Antineoplastic Agents↗

PubMed1991

A case of acquired factor X deficiency with in vivo and in vitro evidence of inhibitor activity directed against factor X.

A 67-year-old woman had symptoms of an upper respiratory tract infection for which she received a five-day course of erythromycin. Epistaxis and gross hematuria subsequently developed, and the patient was found to have a selective Factor X deficiency. She received supportive therapy and prothrombin complex concentrates (Factors II, VII, IX, and X), with subsequent resolution of her transient Factor X deficiency. Her hospital course, however, was complicated by the development of multiple cerebral infarctions. This is the tenth reported case of transient Factor X deficiency not associated with amyloidosis. In seven of the previous cases, as in this patient, the deficiency was associated with a preceding upper respiratory infection. This is the only case, however, with evidence of inhibitory activity in the plasma that was directed toward Factor X.

Aged↗

PubMed1990

Effects of nutritional folate deficiency on the adhesive properties of murine melanoma cells.

Folate deficient murine B16 melanoma cells adhered more rapidly and in higher percentages to plastic plates or dishes coated with laminin or fibronectin than folate replete cells. These changes in the adhesive properties of murine melanoma cells induced by nutritional folate deficiency were not mediated by changes in cell size, proliferative capacity or cell cycle distribution. While melanoma cells served as a suitable surface for prothrombinase complex formation, folate deficiency did not alter this membrane function, suggesting that the membrane changes associated with folate deficiency are relatively specific.

Animals↗

PubMed1990

Phase I trial of intraperitoneal recombinant interleukin-2/lymphokine-activated killer cells in patients with ovarian cancer.

Ten patients with ovarian cancer refractory to conventional therapy were treated with intraperitoneal (i.p.) recombinant interleukin-2 (rIL-2) and lymphokine-activated killer cells (LAK). The 28-day protocol consisted of 6 priming i.p. rIL-2 infusions on days 0, 4, 6, 8, 10, and 12. Leukapheresis was performed for mononuclear cell collection on days 15, 16, 17, and 18 and lymphokine-activated killer cells were given i.p. with the rIL-2 on days 19 and 21. Three additional i.p. rIL-2 infusions were given on days 23, 25, and 27. Three dose levels of rIL-2 were tested: 5 X 10(5), 2 X 10(6), and 8 X 10(6) units/m2 body surface area. The dose-limiting toxicity was abdominal pain secondary to ascites accumulation with significant weight gain. Other toxic effects included decreased performance status, fever, nausea and vomiting, diarrhea, and anemia. Peripheral lymphocytosis and eosinophilia were seen at all dose levels. The maximum tolerated dose is 8 X 10(6) units/m2/dose. Peripheral and peritoneal IL-2 levels were measured with a bioassay using an IL-2-dependent cell line. At the highest dose level, serum IL-2 was greater than 10 units/ml for 18 h. After the first infusion, a 2-log dilution of the i.p. IL-2 was measured in the serum. In the postleukapheresis i.p. IL-2-dosing period less IL-2 was detected in the serum than in the earlier i.p. IL-2-priming period. The induction and persistence of LAK activity were studied. Peritoneal LAK activity was detected as early as 4 days after the first i.p. infusion, by day 11 in all evaluable patients, and persisted for the 6-day interval between priming IL-2 and LAK/IL-2 infusion. Peritoneal lytic activity persisted until day 28 in 5 tested patients. These peritoneal cells retained lytic activity 48 h in culture medium without rIL-2 present. Peritoneal LAK activity correlated with the percentage of mononuclear cells and the percentage of CD56-positive mononuclear cells in the peritoneum. The yield of peripheral lymphocytes after the six i.p. priming doses of rIL-2 correlated with the dose level of rIL-2 infused. Peripheral blood LAK activity showed a minimal, however progressive, increase during the treatment protocol. LAK activity could be enhanced if rIL-2 was present during the 4-h assay. These studies indicate that i.p. rIL-2 infusion induced durable regional LAK activity and primes peripheral blood cells for LAK activity if exposed briefly to additional IL-2.

Adult↗

PubMed1990

Acute pancreatitis complicating therapy of Hodgkin disease: a case report.

Acute pancreatitis developed in a young woman with disseminated Hodgkin disease coincident with cytotoxic treatment. Despite concerns about possible drug-related causes, chemotherapy was continued without further gastrointestinal consequences. This case indicates that pancreatitis need not necessarily alter therapeutic plans for Hodgkin disease. Causes of pancreatitis in the setting of malignancy are reviewed.

Adult↗

PubMed1990

Nutritional folate-deficiency in Chinese hamster ovary cells. Chromosomal abnormalities associated with perturbations in nucleic acid precursors.

Folate deficiency is known to induce chromosomal abnormalities. We used a nutritionally folate-deficient Chinese hamster ovary (CHO) cell culture system to examine modulation of chromosome damage by purine or pyrimidine supplementation. The cells were cultured in folate-deficient (Fol-) medium or Fol- medium supplemented with thymidine (dT) or hypoxanthine (Hx) until population growth arrest. The cultures were then switched to complete medium, permitting the cells to begin cell division. Cell-cycle progression was followed by flow cytometry to identify the first mitosis, when samples for analysis were collected. The mitotic index, frequency of chromosomal aberrations in mitotic cells, and relative distribution of different types of aberrations were determined. Cells grown in Fol- medium supplemented with Hx entered the G2/M phase of the cell cycle at 14 hours after media change as compared with 16 hours for Fol- cultures or 24 hours for Fol- cultures supplemented with dT. Cells cultured in Fol- medium alone or supplemented with dT showed similar frequencies of damage, averaging 20-22%, as compared with 2% for control cultures. In contrast, cells grown in Hx-supplemented medium exhibited a lower frequency of damaged mitoses (15%), as well as a reduction in certain types of abnormalities. This latter finding is surprising in light of our previous work showing that the presence of Hx during folate deficiency produced a more severe perturbation of phenotype (cellular enlargement) and growth control (S-phase delay and cell killing) than did dT supplementation or the absence of both nucleotide precursors.

Animals↗

PubMed1989

Immunosuppressive properties of chloroquinoxaline sulfonamide.

Chloroquinoxaline sulfonamide (CQS), a sulfanilamide derivative with antitumor activity, was found to be toxic to lymphoid tissue during preclinical studies. The mechanism of this toxicity appears to involve profound inhibition of lymphocyte activation. Incubation of human peripheral blood mononuclear cells (PBMNCs) with CQS decreased cellular incorporation of thymidine and deoxyuridine in a dose-dependent manner. Analysis of cell cycle distribution by flow cytometry indicated that CQS blocked movement out of the G0/G1 phase. Drug-treated cells were smaller and expressed fewer receptors for interleukin-2 (IL-2) and transferrin than untreated mitogen-stimulated lymphocytes. These observations support the notion that CQS has cell cycle specificity in regulating lymphocyte proliferation. As little as 10 microM CQS markedly inhibited both human lymphocyte and murine CTLL cell replication in response to IL-2 containing growth factors. However, CQS did not block secretion of IL-2 into culture supernatant fractions by human PBMNCs. Finally, CQS inhibited in vitro production of immunoglobulins G and M by mitogen-stimulated lymphocytes, primarily by causing cytotoxicity. In all of these drug effects, CQS was approximately one to two logs more potent than the parent compound, sulfaquinoxaline (SQ). These studies indicate that CQS inhibits essential basic processes in human lymphocytes. This agent may find use as an immunosuppressive drug.

Animals↗

PubMed1989

Nutritional folate deficiency in Chinese hamster ovary cells. I. Characterization of the pleiotropic response and its modulation by nucleic acid precursors.

Nutritional folate deficiency in Chinese hamster ovary (CHO)-K1 cells inhibited population growth rate and caused growth arrest within 3 days of culture in Fol- medium [without folate, hypoxanthine (Hx), and thymidine (TdR)]. Coincident with impaired population growth was a transient delay in cell cycle progression through S phase and an increase in cell size. The growth-arrested population of predominantly G1 phase cells exhibited an increased adhesion to the culture substratum. There was a time-dependent loss of cell reproductive capacity. All these various perturbations of cellular phenotype induced by folate deficiency were prevented by the addition of folate or a combination of TdR and Hx to the Fol- medium. However, the singular presence of each nucleotide precursor differentially affected the pleiotropic response. The addition of Hx to Fol- medium exacerbated the aforementioned abnormalities, producing a threefold increase in mean cell volume, a 72 hr accumulation of cells in the S phase of the cell cycle, and a rapid demise in cell clonogenicity. Unexpectedly, we found reduced cell adhesion in these cultures. In contrast, folate-deficient cells supplemented with TdR exhibited a general amelioration of cell perturbations with respect to cell size, cell cycle distribution, and reproductive viability. Notably, such populations were not released from growth inhibition or subsequent growth arrest, and the cells became elongated and highly adherent with time. When cell populations from each of the three conditions of folate-deficient culture were released from growth arrest by addition of complete medium, the respective profiles of synchronous cell cycle progression were distinctive.

Animals↗

PubMed1988

Cellular pharmacology of chloroquinoxaline sulfonamide and a related compound in murine B16 melanoma cells.

Chloroquinoxaline sulfonamide (CQS), a chlorinated derivative of sulfaquinoxaline (SQ), inhibited proliferation of murine B16 melanoma cells, but only when relatively high drug concentrations (1 mM) were used. The inhibition of cell growth by CQS was at least partially reversible by incubation in drug-free medium. Incubation of melanoma cells with CQS was associated with an arrest of the cell cycle in G0/G1 as measured by flow cytometry. The drug slightly decreased uptake of radiolabeled deoxyuridine and thymidine after 24- and 48-hr incubation periods but increased nucleoside incorporation at 72 hr. No evidence of intercalation with DNA was found. Because SQ previously was reported to inhibit an aspect of folate metabolism, we investigated the possibility that CQS limits tumor cell growth by altering folate homeostasis. This appears unlikely, however, in view of the following observations: (1) the cytotoxic effects of CQS could not be reversed by folinic acid; (2) deoxyuridine suppression of thymidine incorporation was not affected by CQS treatment; (3) CQS did not inhibit dihydrofolate reductase from mammalian or bacterial sources; and (4) CQS toxicity in mice was not reduced by folinic acid. Experiments performed with analogues modified in the quinoxaline and para-amino phenyl functions indicated that tumor cell inhibition did not require preservation of the conventional sulfonamide structure.

Animals↗

PubMed1988

Effects of folate deficiency on the metastatic potential of murine melanoma cells.

Experiments were designed to measure the effect of folic acid deficiency on a major determinant of cancer lethality, the propensity to form metastases. Murine B16 melanoma cells (F10 strain) were grown in folate-deficient and -supplemented media. After 3 days, cells in the deficient medium had restricted proliferative capacity, low folate levels by bioassay, increased cell volume, abnormal deoxyuridine suppression tests, accumulation of cells in S phase by flow cytometry, and increased numbers of DNA strand breaks. These folate-deficient cells consistently initiated more pulmonary metastases than control cells when injected into host mice. Cell size did not appear to be a major factor in pulmonary metastasis formation. In vitro growth rates and cloning efficiencies were comparable for cells in both types of medium as was subcutaneous growth of tumors. We conclude that folate deficiency increases the metastatic potential of cultured melanoma cells.

Animals↗

PubMed1988

Copper deficiency and sideroblastic anemia associated with zinc ingestion.

Anemia and neutropenia developed in a man who took pharmacologic doses of supplemental zinc. Laboratory investigation showed high zinc level, hypocupremia, low ceruloplasmin level, and ringed sideroblasts. All resolved after withdrawal of zinc. Self-administered zinc appears to have caused severe copper deficiency, with secondary anemia and neutropenia. Physicians should be aware of this deleterious and completely reversible effect of megadose mineral therapy. Zinc ingestion or exposure should be considered in the differential diagnosis of unexplained anemia, leukopenia, or sideroblastic anemia.

Adult↗

PubMed1987

Inhibition of lymphocyte nucleic acid metabolism and antibody production by trimetrexate.

Trimetrexate is a lipid soluble dihydrofolate reductase inhibitor which, unlike methotrexate, does not depend upon the membrane folate transport system for cell entry. We investigated the possibility that trimetrexate (but not methotrexate) might permeate intermitotic lymphocytes and, following stimulation, impair only the responding cells, rather than all dividing cells, as is the case with methotrexate. Peripheral blood mononuclear cells from normal individuals were incubated for 1 hr in three moderate to high concentrations (1, 10 and 100 microM) of methotrexate or trimetrexate, washed, and incubated with phytohemagglutinin. Intracellular folate activity, as assessed by the deoxyuridine suppression test, was abnormal at all three concentrations of trimetrexate but only at the highest concentration of methotrexate. Similarly, incorporation of [3H]deoxyuridine was depressed profoundly in trimetrexate-treated cells (2% of control) but unaffected by methotrexate. Analysis of cell cycle distribution by flow cytometry confirmed G0 + G1 arrest in trimetrexate but not methotrexate-treated cells. Neither drug altered morphologic transformation, Tac antigen expression, or incorporation of [3H]thymidine by the "salvage" pathway. Therefore, brief exposure to methotrexate has little effect on intermitotic lymphocytes, whereas trimetrexate very specifically inhibits the conversion of deoxyuridine to thymidine in these cells and leads to the arrest of DNA synthesis in the G0 + G1 phase. This metabolic abnormality markedly reduces in vitro antibody synthesis: a 1-hr treatment of lymphocytes with 10 or 100 microM trimetrexate prior to incubation with pokeweed mitogen on four occasions completely inhibited both IgG and IgM secretion. Similar treatment with methotrexate had no effect until the highest concentration (100 microM) was used. We conclude that brief exposure of peripheral blood mononuclear cells to the nonclassical dihydrofolate reductase inhibitor, trimetrexate, results in inhibition of nucleic acid synthesis and impairment of antibody production. This drug effect may permit more incisive modulation of immune responses.

Antibody Formation↗

PubMed1986

Further characterization of the in vitro tumoricidal activity of staphylococcal protein A.

Treatment of plasma or serum from leukemic patients with solid phase staphylococcal Protein A induced leukemic blast cell lysis in vitro, but this effect was relatively independent of the amount of immunoglobulin G (IgG) removed. Samples with approximately equal cytotoxic activity contained markedly different IgG levels, while samples with similar IgG levels had a wide range of tumoricidal activity. Assays of plasma samples collected during a perfusion of one plasma volume through a Protein A-Sepharose column indicated that the duration of the procedure had a greater effect on cytotoxic activity than did the amount of IgG removed. Neither added leukemic nor normal IgG significantly improved blast cell viability in treated serum. Cytotoxic activity was not dialyzable and concentrated in the Mr less than 100,000 fraction of samples separated by filtration. Treated cytotoxic serum samples did not have important Clq binding activity. These results suggest that the in vitro tumoricidal activity of solid phase Protein A is probably due to a toxic substance added to serum during immunoadsorption rather than to its immunoadsorptive capacity.

Antigen-Antibody Complex↗

PubMed1985

Horner's syndrome: an unusual presentation of Hodgkin's disease.

Horner's Syndrome (ptosis, anisocoria, and anhydrosis) developed in a 22-year-old woman. A mediastinal mass was noted on chest x-ray. Further evaluation led to a diagnosis of Hodgkin's disease, nodular sclerosis type. Horner's syndrome is an unusual initial manifestation of Hodgkin's disease, and, in this case, it was due to oculosympathetic damage from mediastinal compression. Because the potential for cure is high in Hodgkin's disease, this diagnosis should be considered in patients presenting with Horner's syndrome.

Adult↗

PubMed1985

Effects of plasma treatment with purified protein A and Staphylococcus aureus Cowan I on spontaneous animal neoplasms.

Eleven dogs with spontaneous neoplasms were intensively treated with an immunoadsorption system consisting of a continuous flow centrifuge, Protein A-Sepharose columns, and a semi-automatic elution system. Despite consistent and substantial lowering of immunoglobulin G levels, tumor regression was noted in only one of 11 dogs. In contrast, infusion of small volumes of plasma after incubation with heat and formalin-treated Staphylococcus aureus Cowan I resulted in a tumoricidal response in five of six animals. These results suggest that tumor necrosis is probably not induced by Protein A-mediated removal of humoral "blocking" factors.

Animals↗

PubMed1984

Folate metabolism and chromosomal stability in the fragile X syndrome.

Folate metabolism and the effects of folic acid on chromosome stability were studied in four related patients with the fragile X syndrome. In three adults, uptake and subsequent utilization of folate compounds for conversion of deoxyuridylate to thymidylate by marrow cells and stimulated lymphocytes, and the affinity and maximal transport velocity of erythrocyte membrane carriers, were normal. Numbers of sister chromatid exchanges and double-stranded DNA breaks were comparable in cells from patients and control subjects, but both were increased after incubation in folate-deficient media. In vitro expression of the fragile site was strikingly reduced by oral folate therapy. It is concluded that the folate-sensitive chromosomal defect in this syndrome is limited to a specific site, Xq28, and there is no generalized tendency to frequent DNA breaks or recombination. Although expression was modified by folic acid treatment in the patients, no consistent abnormality of folate metabolism could be identified.

Adult↗

PubMed1984

In vitro tumoricidal activity of immunoadsorbed leukemic serum.

We studied the ability of untreated or immunoadsorbed acute myelogenous leukemia (AML) sera to kill AML blasts. Culture of blasts with sera adsorbed to protein A-bearing Staphylococcus aureus Cowan I (SAC), resulted in a marked loss of blast viability (42.7% of control). Immunoadsorption against non-protein A-bearing Wood 46 strain of S. aureus did not induce serum cytotoxic activity (94.8% viable cells). Sera adsorbed to Sepharose-bound protein A also killed blasts in vitro (64.3% viable cells). The addition of untreated sera to SAC-treated cultures partly abrogated the effect, suggesting a blocking substance in untreated serum. Cytotoxicity was not complement-dependent nor did it appear to be cell mediated. It was, however, eliminated by trypsin treatment of SAC-treated sera. These studies suggest that SAC-treated AML serum contains a protein that is cytotoxic to AML blasts, and that this protein is partly inactivated by untreated AML serum, possibly through interaction with immunoglobulins. The mechanism described here may be one of several mechanisms leading to tumor necrosis in tumor-bearing hosts treated with SAC-immunoadsorbed plasma.

Cells, Cultured↗

PubMed1983

Antithymocyte globulin treatment of severe aplastic anaemia.

Nineteen patients with severe aplastic anaemia were treated with antithymocyte globulin. Ten patients obtained remissions (transfusion independent, at least 45000 platelets and 2000 PMN/mm3) within 2-3 months and continue in remission 5-35 months after antithymocyte globulin. Ages of responders ranged from 17 to 71. Complications of antithymocyte globulin included arthralgias, rash, serum sickness, angioedema and fever. Two patients died during, two shortly after, and one 10 months after therapy. One patient with a previous remission following antithymocyte globulin relapsed and achieved a second remission with retreatment. Previous androgen therapy did not affect outcome since two of four patients with and eight of 15 patients without previous androgen therapy achieved remission with ATG. Treatment with antithymocyte globulin is a promising alternative to bone marrow transplantation in the treatment of severe aplastic anaemia.

Adolescent↗