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Biomedical subjects

A Perez

Publications and source records attributed to A Perez.

At least 181 records · Page 10Linked to original sources
PubMed1985

Incidence of involvement of the B and T lymphocyte lineages in chronic myelogenous leukemia.

Peripheral blood specimens were obtained from 22 patients with Philadelphia chromosome (Ph1) positive chronic myelogenous leukemia (CML) (16 in chronic phase, 2 in an accelerated phase, and 4 in blast crisis). Studies were performed to determine the frequency of the presence of the Ph1 chromosome in cells of lymphoid lineages. Rosetted (E+) lymphocytes (T lymphocytes) from nine patients in chronic phase and one patient in blast crisis were stimulated with T cell growth factor interleukin 2 (IL-2) and/or phytohemagglutinin (PHA). All ten patients had sufficient T lymphocyte metaphases for analysis and of a total of 461 metaphases examined, only one contained the Ph1 chromosome. Nucleated cells of density less than 1.077 g/mL were infected with Epstein-Barr virus (EBV). Following infection, cell lines were established from individual colonies attached to egg albumin-coated Lab-Tek slide chambers (clonal cell lines) or from suspension culture in 96-well tissue culture cluster dishes (nonclonal cell lines). Cell surface and intracellular marker analysis confirmed the B lymphocyte phenotype of all the cell lines examined. B lymphoblastoid cell lines were established from 16 of the 22 patients. All lines from 12 patients were Ph1-negative. From two chronic phase patients, both Ph1-positive and Ph1-negative lines were established. From one patient in an accelerated phase, only Ph1-positive lines were established. From another patient in blast crisis (of myeloblastic phenotype), only Ph1-positive lines were established initially; however, five months later, after the patient had been treated with mitoxantrone, only Ph1-negative lines were derived from this patient. Based on these results, it appears that most B cells and mature T cells in most CML patients are Ph1-negative, but that about 25% of patients have predominantly Ph1-positive B cells or a mixture of Ph1-positive and Ph1-negative B cells that are capable of growing as established cell lines after transformation with EBV.

Adolescent↗
PubMed1982

Effects of Hoechst 33342 on survival and growth of two tumor cell lines and on hematopoietically normal bone marrow cells.

Our objective in this investigation was to determine whether Hoechst 33342, which is widely recognized as a DNA specific fluorochrome for living cells, is in fact nontoxic and kinetically nonperturbing at dye concentrations required to achieve acceptable DNA distributions. Three cell types were tested: HeLa S-3; SK-DHL2, a human lymphoma cell line; and hematopoietically normal human bone marrow cells. In the third system, only the cloning efficiencies were determined. Results differed considerably for the different cell types. While HeLa cells yielded excellent DNA distributions and were almost completely resistant to the cytotoxic and cytokinetic effects of the dye, SK-DHL2 cells were highly sensitive to the fluorochrome even at dye concentrations which produced very poor DNA distributions. Human bone marrow cells were intermediate in their stainability and toxicity response, and acceptable DNA distributions could be obtained at the nontoxic dye concentration of 2.5 muM. Clearly, different cell types differ considerably with respect to their cytotoxic and kinetic responses to Hoechst 33342. In some cases it may not be possible to ensure adequate staining of the cells for flow cytometry without significantly altering their viability and/or proliferative behavior.

Benzimidazoles↗
PubMed1982

Mortality and morbidity in infants less than 1,001 grams birth weight.

A prospective study of 54 infants with birth weights of 1,000 gm or less was conducted over a period of two years. Of the 26 infants who survived, 24 weighed between 750 and 1,000 gm; two infants died after discharge and one was lost to follow-up, leaving 23 in whom serial observations were made over 18 months to 3 years of age. The incidence of neurologic deficit in these infants was 17% and of intellectual deficit, 13%. Of the four who were abnormal neurologically, two had spastic quadriparesis, one static encephalopathy, and one hydrocephalus secondary to intraventricular hemorrhage. The three with intellectual deficit had a developmental quotient less than 85. Of the perinatal factors examined, only birth asphyxia correlated significantly with both neonatal mortality and subsequent morbidity. Six (26%) of the surviving infants had mild, nonblinding retrolental fibroplasia; only one of them had a significant refractive error that required corrective lenses for vision. Sepsis was a significant contributor to neonatal mortality in ten of 28 infants who died, but was detected in only one survivor. Although the prognosis for the infant weighing 1,000 gm or less at delivery has improved significantly, there is promise for still further improvement by reducing perinatal asphyxia.

Asphyxia Neonatorum↗
PubMed1977

Treatment of intestinal amoebiasis and vaginal trichomoniasis with panidazole and its comparison with metronidazole.

A dose range study in 18 patients suffering from intestinal amoebiasis and treated with doses of panidazole between 1.0 and 2.0 g per day for six days revealed that the best therapeutic results were obtained with the higher dose. This dose was then compared with metronidazole, at the same dose, in a clinical trial in 100 patients with intestinal amoebiasis. Cure rates were 68% and 80% for the two drugs respectively. In 100 cases of vaginal trichomoniasis treated with panidazole at the dose of 1.0 g per day for seven days in half of the patients and for 10 days in the other half, we obtained 50% and 60% cure rates. The results of our studies with both amoebiasis and trichomoniasis were not superior to those obtained with metronidazole and other nitroimidazole derivatives. Side effects were found in 74% of the patients treated for amoebiasis and in 46% of the cases treated for trichomoniasis. No toxic effects were revealed by haematological, biochemical and renal function tests nor by cardiovascular studies.

Adult↗
PubMed1976

Significance of the secretion of human prolactin and gonadotropin for puerperal lactational infertility.

The causes of puerperal infertility in lactating women are poorly understood. The controlling centres may be either the hypothalamic-pituitary axis or the ovary (or both). We studied the secretory dynamics of prolactin and gonadotropins in healthy, normal, lactating and non-lactating women after administering either gonadoliberin to assess pituitary responsiveness or human menopausal gonadotropins to assess ovarian responsiveness during the puerperium. A reciprocal relationship was observed between the secretion of gonadotropins and the secretion of prolactin after the nipples of mothers who were breast-feeding had been stimulated for 30 min. The absence of a short-loop negative feedback control by prolactin for gonadotropin secretion was not confirmed because cyclic secretion of gonadotropin was not necessarily impaired by hyperprolactinaemia. Hyperprolactinaemia did, however, appear to impair the function of the corpus luteum in women suffering from non-puerperal galactorrhoea. We postulate a multifactorial mechanism for puerperal infertility based initially on the peripheral concentration of prolactin and gonadotropins and, in some poorly defined way, on the cerebral concentration of catecholamines.

Amenorrhea↗
PubMed1976

Cell kill kinetics with hydroxyurea.

The effects of various concentrations of hydroxyurea (HU) on a human lymphoid cell line in exponential growth phase have been studied using a combination of methods, including determination of the total and viable cell counts; the cells relative DNA content, measured in a flow microfluorimeter after staining with a fluorescent Feulgen technique; the mitotic index; and the percentage of cells incorporating thymidine-3H (TdR-3H) during brief and continuous exposure to the isotope both in the presence and absence of colcemid. A significant redistribution of the cells in the various phases of the cell cycle occurred during the first 24 hr of continuous treatment with 10(-3) M and 10(-2) M HU as follows: (1) division of cells in G2; (2) depletion of mid and late S phase cells due to early cell death; (3) movement of most G1 cells at a normal rate into early S phase where they accumulate; and (4) arrest of the remaining cells in G1, which represented the surviving population after treatment for 96 hr or longer. After removal of the drug, the cell fraction blocked in early S phase progressed semisynchronously through S, but many of the cells were unable to complete division. Their capacity to recover depended on the drug concentration and duration of exposure, but in general the cellular injury caused by HU was more reversible than that caused by "equivalent" concentrations of arabinosylcytosine.

Cell Count↗
PubMed1976

Human lactational response to oral thyrotropin releasing hormone.

Several studies were designed to evaluate the effect of oral TRH on prolactin (PRL) secretion and mammary function in nursing women. Initially, efficacy was studied in nursing women following 5 mg TRH. PRL levels rose to a mean maximum of 46.3 ng/ml above baseline at 60 min. Plasma TSH also incresed from a mean baseline of 2.6 to 17.6 muU/ml at 180 min. No changes were observed following placebo. In order to observe the long term effects of oral TRH, two groups of women in full nursing were studied. Beginning on day 29 postpartum, either 5 mg TRH or placebo were taken twice daily for four weeks. No chronic elevations were observed in maternal PRL and TSH or in infant TSH before or after one month of either regimen. Milk composition expressed in terms of per cent protein and per cent fat did not differ between the groups. Weekly gonadotropin levels were also similar as were infant weight gain and growth. In a group of women with lactational insufficiency receiving 5-20 mg TRH twice daily for five days, basal PRL concentrations markedly increased. While changes in milk composition were not significant, fat percentages increased slightly and protein percentages declined. Breast engorgement and milk letdown increased and full nursing was restored. While the oral TRH used in fully nursing women had no demonstrable effect on mammary function, it may prove useful in those women with lactational insufficiency. Because two women developed iatrogenic hyperthyroidism following 40 mg oral TRH twice daily, care must be exercised in determining the dosage to be employed.

Adolescent↗
PubMed1976

Cri du chat syndrome and translocation t(5p--;18p+).

Two new cases of "cri du chat" syndrome are reported in sisters aged 2 years and one month, respectively. These cases allowed us to detect a translocation t(5p--;18p+) in the mother and to study the familial segregation of this structural chromosome anomaly. At the same time, results from the dermatoglyphic analysis of the propositi as well as those of the carriers of the translocation are also reported.

Child, Preschool↗