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Biomedical subjects

J Quesada

Publications and source records attributed to J Quesada.

At least 37 records · Page 2Linked to original sources
PubMed1985

Growth factor-mediated tumor cell proliferation in hairy cell leukemia.

Leukemic B cells from seven patients with hairy cell leukemia (HCL), six of which contained the Tac antigen, were assayed in vitro for growth factor-mediated cell proliferation. The HCL cells showed typical phenotypic profiles by monoclonal antibody analysis. The tumor cells, which do not grow spontaneously in vitro, were found to proliferate in all but one case in response to partially purified B cell growth factor (BCGF) without anti-mu or Sac activation. Recombinant interleukin 2 however produced only a marginal response and could not support leukemic cell growth in vitro. BCGF, however, did stimulate in vitro cell growth and supported the establishment of continuous (greater than 60 d in vitro) in four of the seven HCL cases.

Antigens, Neoplasm↗
PubMed1985

Effect of thyroid hormones on the glycolytic enzyme activity in brain areas of the rat.

The glycolytic metabolism through the key enzymes, hexokinase, phosphofructokinase, pyruvate kinase and lactate dehydrogenase, have been studied in the brain areas: anterior cortex, amygdala, hypothalamus, septum and hippocampus in adult rats with pharmacologically induced hyperthyroidism. The oxidative metabolism of glucose is accelerated in most brain areas by treatment with high doses of T3, as is shown by the increase in HK activity, approaching normality on reducing the dose. This decrease can also by observed in the PFK activity through the effect of assayed doses of thyroxine. The anterior cortex is the only brain area that does not show significant variations of PK activity through the effects of treatment with thyroid hormones. On the other hand, a general inhibition of the glycolytic anaerobic pathway by treatment with T3 was observed.

Amygdala↗
PubMed1985

Ultrastructure of the granulopoietic microenvironment in the tunica propria of the bursa of Fabricius of white Leghorn chicken embryo.

Granulopoietic areas of tunica propria of chicken embryo bursa (stage 38 to 45 H-H) were composed of fibroblasts, reticular cells with and without lipid droplets and macrophages within a network of collagen fibers. We suggest that the reticular cells with lipid droplets could have the same microenvironmental significance as adipocytes of other granulopoietic organs.

Animals↗
PubMed1984

Prognostic factors in hairy cell leukemia (leukemic reticuloendotheliosis).

Prognostic factors were examined in 31 patients with hairy cell leukemia seen at M. D. Anderson Hospital. Long survival from presentation was significantly associated with ease of aspiration of iliac crest bone marrow, absence of major infection, hemoglobin greater than 10 g/dl, and absence of a prior history of pneumonia. Long survival from splenectomy was associated most closely with absence of a prediagnosis history of pneumonia, suggesting that a long-standing host defense abnormality may exist that is not corrected by splenectomy. Generally, patients with sustained improvement in hematologic parameters postsplenectomy lived longest from splenectomy, although the results were not statistically significant.

Age Factors↗
PubMed1983

Antibodies to human leucocyte interferons in cancer patients.

During the course of clinical investigation of partly purified human leucocyte interferon (IFN) prepared at the Finnish Red Cross (PIF), neutralising IgG antibodies to human leucocyte IFN were detected in the sera of 3 patients with cancer. In 2 of these patients, the antibodies were detected in serum before treatment with PIF. In the third patient antibodies developed during the course of treatment. Antibody titres against six recombinant human leucocyte IFN sub-types and one recombinant hybrid human leucocyte IFN were different in the 3 patients.

Antibodies↗
PubMed1982

Antibody-dependent cell-mediated cytotoxicity in human cancer: characterization of patient leukocyte activity and treatment effects.

Antibody-dependent cell-mediated cytotoxicity (ADCC), medicated by peripheral blood Hypaque-Ficoll separated mononuclear cells, was studied in humans using chicken erythrocytes (CRBC) incubated in a 1:1200 dilution of rabbit anti-CRBC and human B erythrocytes (HRBC) incubation in a 1:20 dilution of isoantibody. At the optimal target effector ratio of 3:1, ADCC to both CRBC and HRBC was significantly higher than normal in 27 lung cancer, 18 malignant melanoma, and seven colon cancer patients, but not in 20 breast cancer patients. Chemotherapy (single-agent or combination) in 12 patients did not effect ADCC in vitro but significantly suppressed ADCC to both targets after only four or five days of therapy in vivo (ADCC to CRBC, 47.4 to 24.1% lysis: ADCC to HRBC, 48.1 to 16.3% lysis). Immunotherapy with intravenous (IV) corynebacterium parvum or IV methanol extraction residue of BCG (MER) boosted ADCC to both targets within four to seven days of the first dose. It was found that ADCC to HRBC but not to CRBC was completely absent in three cases of active hairy cell leukemia but was present in two cases in remission. The ADCC to HRBC showed an age-dependent increase in both the 51 normal subject and the cancer patients. This was not observed for ADCC to CRBC. The ADCC to CRBC was mediated mainly by an Fc-receptor-positive, nonadherent, small lymphocyte, and ADCC to HRBC was mediated entirely by an adherent monocyte. The ADCC did not correlate significantly with the H3 thymidine incorporation of peripheral blood mononuclear cells, cultured without stimulation for either one or seven days. It also did not correlate with the number of residual granulocytes in the mononuclear cell suspensions. Measurement of ADCC is a useful method of characterizing host defense in malignant disease and its modification by therapy.

Age Factors↗
PubMed1982

Recombinant leukocyte A interferon: pharmacokinetics, single-dose tolerance, and biologic effects in cancer patients.

Sixteen patients with advanced cancer were treated with recombinant-DNA-produced pure leukocyte A interferon (IFLrA) intramuscularly in doses ranging from 3 to 198 X 10(6) units. with interval periods of 72 to 96 hours between doses. At the two lowest doses of 3 and 9 million units, there was a cross-over evaluation between IFLrA and partially pure leukocyte interferon (IFN-C) produced from human cells. THe maximum observed serum concentration of IFLrA measured by enzyme immunoassay and bioassay increased with increasing doses. The mean serum concentrations of IFLrA and IFN-C were similar. Clinical effects produced by IFLrA and IFN-C were similar, including fever, chills, myalgias, headache fatigue, and reversible leukopenia and granulocytopenia. Eight patients had transient and mild numbness of the hands or feet, or both. Three patients developed low titers of antibody to IFLrA, Seven of 16 patients showed objective evidence of tumor regression during the study.

Adult↗
PubMed1975

Xerophthalmia and anterior-segment blindness among preschool-age children in El Salvador.

A countrywide prevalence survey of 9,508 children was conducted in El Salvador to determine the prevalence of anterior-segment abnormalities and magnitude of clinical vitamin A deficiency. Thirty-six children had corneal opacities, 56% of them secondary to trauma. Such traumatic corneal opacities were 19 times more frequent among urban than rural children, 57.6 vs. 3.1 per 1,000. Keratomalacia accounted for only 8% of all corneal opacities, and for one (and possibly two) of the five cases of bilateral anterior-segment blindness encountered. The prevalance of Bitot spots and vitamin-A-related corneal opacities was 5.3 and 3.2 per 10,000, respectively. There are an estimated 43 new surviving cases of vitamin-A-related corneal opacities in the country each year, one third of which result in bilateral blindness. Fifteen percent of all children examined had grossly purulent conjunctivitis.

Blindness↗
PubMed1975

Mass distribution of vitamin A and the prevention of keratomalacia.

A retrospective review of 3,490 adminissions to the major pediatric facility in El Salvador was undertaken to determine whether biannual administration of massive doses of vitamin A (200,000 international units) to all availabel 1- to 4-year-old children was effective in preventing keratomalacia. During the 12 months preceding and following initiation of the program, the number of children admitted with presumed vitamin-A-related corneal destruction (33 vs. 31) and proportion of all malnourished admissions with such destruction (26 vs. 25 per 1,000) were similar. The seasonal distribution of these cases remained unchanged, the usual summer peak closely following the first distribution. Unexpectedly, 48% of the children had been ineligible for participation in the program, the vast majority being under 1 year of age. Only 80% of eligible children had actually received the vitamin. Corneal destruction was invariably accompanied by severe, generalized malnutition. Mortality among girls with corneal destruction (28 per 1,000) was almost three times that of boys, or malnourished patients as a whole.

Age Factors↗
PubMedDate not supplied

[Positron emission tomography with F-18-FDG: a new tool in the evaluation of patients with head and neck tumors].

INTRODUCTION: Positron emission tomography using fluoro-deoxyglucose (PET-FDG) imaging has been shown to be effective in detecting and staging malignancies based on tumor glucose metabolism. The aim of the study was to evaluate the use of PET-FDG for the detection of metastatic lesions as well as early recurrence in patients with head and neck tumors. MATERIAL AND METHODS: Eleven patients were examined with PET-FDG to study the reliability of PET in assessing regional nodal status and in identifying distant metastasis (group I) and 37 patients who had previously received curative treatment and who presented differential diagnostic problems were imaged to differentiate between scar and residual or recurrent cancer (group II). PET-FDG studies were compared to results of computed tomography (CT) in 35 patients, magnetic resonance imaging (MRI) in 4 patients and both techniques in 6 patients. RESULTS: All PET-FDG studies were positive in group I, while CT failed to detect metastatic lesions in three patients. In group II PET-FDG accurately detected recurrent disease in 22/25 patients, while CT/MRI were negative in 4 cases and equivocal in 6 cases. However, there was a false positive PET study with equivocal CT in a patient with local infection. CONCLUSION: PET-FDG was highly effective in detecting metastatic cervical lymph nodes in head and neck tumours. It was most helpful in differentiating residual or recurrent tumour from scar sequelae and it enhanced the diagnostic accuracy when CT and MRI were equivocal due to anatomical distortions.

English Abstract↗