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Biomedical subjects

H Moreno

Publications and source records attributed to H Moreno.

At least 91 records · Page 5Linked to original sources
PubMed1979

Identification and management of psychosocial and environmental problems of children with cancer.

An occupational therapist working as a rehabilitation specialist on the hematology-oncology team for pediatric malignancy identified and sought solutions for problems encountered among 49 pediatric oncology patients and their families. The occupational therapist's role as "CARE (CAncer REhabilitation) counselor" involved working with the patient, family, and team members to meet needs and provide services other than direct medical treatment. A variety of environmental needs and psychosocial problems were identified and managed. Prospective interaction from the time of diagnosis, resulting in 63 percent solution of all problems, was more effective than intervention initiated at other stages of illness.

Adolescent↗
PubMed1978

Membrane-bound cooperative enzymes. Stokes' radii, Hill plots and membrane fluidity in the regulation of adenosinetriphosphatase from Escherichia coli.

The soluble Ca2+-ATPase from Escherichia coli had a distinctive behavior with respect to inhibition by Na+ measured at 36 degrees C and 19 degrees C. At the first temperature the Hill plots are linear and show a slope of 1.1 while at 19 degrees C the plots are biphasic, with slopes of 1.8 and 0.8 before and after the break, respectively. The break occurs at about 50 nM NaCl. Gel chromatography was performed in jacketed Sepharose 4B columns kept at 2 temperatures in the presence of different concentrations of NaCl. It was found that the Stokes' radius of the enzyme was dependent on the temperature and on the salt concentration. Equilibrium sucrose gradients run at 19 degrees C showed that the sedimentation constant of the enzyme remained constant irrespective of the NaCl concentration used. It is concluded that a "folding" of the enzyme takes place in the presence of NaCl, the process being complete at about 50 mM NaCl at 19 degrees C and at about 20 mM at 36 degrees C. The results are in excellent agreement with the kinetic data: the "folded" or "compact" configuration would show no cooperative response towards Na+ while the "expanded" conformer would present strong cooperativity. This is also in agreement with the results obtained with the enzyme embedded in the membrane: when the membrane is fluid a high n value (Hill coefficient) is found; when the membrane is more rigid the value of n falls. A model explaining all our results is proposed and discussed.

Adenosine Triphosphatases↗
PubMed1978

Membrane cooperative enzymes. High molecular specificity for blocking action of thyroxine on triiodothyronine effect in rat erythrocyte and Escherichia coli systems.

The molecular specificity for the blocking action of thyroxine on the triiodothyronine effect in the cooperativity of membrane-bound rat erythrocyte acetylcholinesterase and Escherichia coli Ca2+-ATPase was analyzed. Changes in the values of n (Hill coefficient) were obtained at strict physiological levels of these hormones. The structural requirements of the thyroid hormones to modify the membrane-bound systems were studied using various analogues of these hormones. In the erythrocyte system, a very high molecular specificity for triiodothyronine and thyroxine actions was found. The L-alanine side is essential to carry out both the allosteric desensitization and the blocking effects. The blocking ability of thyroxine is characterized by the presence of iodine in the 5' position. The bacterial system presented only specificity for the triiodothyronine allosteric desensitization. A system of membrane-bound enzymes for the study of the actions of thyroid hormones, is presented here.

Acetylcholinesterase↗
PubMed1978

Histologic grading of Wilms' tumor as potential prognostic factor: results of a retrospective study of 26 patients.

A histologic grading system based on tumor differentiation was applied in a retrospective study of 26 patients with Wilms' tumor to determine if it might provide an index to prognosis. The results were compared to those obtained by applying a histologic classification based on the presence or absence of individual histologic structures to the same tumors. Low grade tumors with predominance of differentiated structures--glomeruli and tubules--were associated with a better cure rate than high grade tumors composed mainly of undifferentiated spindle elements. The presence of undifferentiated large cells correlated with poor cure rate. The findings suggest that histologic grading may be valid as a prognostic factor in Wilms' tumor.

Adolescent↗
PubMed1978

Granulopoiesis in chronic myeloproliferative disorders in children.

Four children with chronic myeloproliferative disorders (three with Philadelphia [Ph1] chromosome-positive chronic myelogenous leukemia [CML] were studied with soft agar culture at diagnosis (before therapy) in an attempt to define abnormalities in granulopoiesis. The three patients with CML had elevated peripheral blood golony-forming cells (CFCs) and/or normal or decreased bone marrow CFCs (in those studied). Colony-stimulating activity (CSA) was markedly decreased or absent at diagnosis in all three. Maturation of myeloid cells eithin the colonies in agar was normal, indicating that no block in myeloid maturation was present. These findings are in general agreement with results previously reported in untreated adults with Ph1 chromosome-positive CML and further define the similarity with the adult form of the disease. One Ph1 chromosome-negative patient with a clinically similar chronic myeloproliferative disorder was studied and had similarly elevated peripheral blood CFCs. She had normal CSA with a similarly high WBC count. This finding was unexpected and suggests that, unlike the patients with CML, her monocytes were capable of elaboration CSA. This difference might prove helpful in the classification of this type of disorder in cases where the Ph1 chromosome abnormality is not present.

Adolescent↗
PubMed1978

Osteosarcoma: a review of 50 patients treated at the University of Alabama in Birmingham Medical Center between 1944 and 1975.

Only 12% of 50 patients lived 5 years or longer. Those who survived the longest were those with the tumor in the distal part of the lower extremity, with a well differentiated or chondroblastic tumor, or those who underwent radical surgery. Patients treated with surgery and chemotherapy lived about 1.5 months longer than those treated with sugery alone and about 1.2 months longer than those who had radiation included in the therapy. For a patient with a diagnosis of osteosarcoma, the prognosis was to be grave, no matter which methods of treatment were used.

Adolescent↗
PubMed1977

Cytosine arabinoside and 6-thioguanine in the treatment of childhood acute myeloblastic leukemia.

Twenty children with acute myeloblastic leukemia were given induction and maintenance regimens combining cytosine arabinoside (ARA-C) and 6-thioguanine (TG). Two died before completing induction therapy and were considered unevaluable. Of the 18 remaining patients, 3 died shortly after induction, 2 had no response, 1 had a partial response and 12 (66%) had a complete remission (CR) lasting 4 to 68 months. Six still survive: two in their initial CR and four who relapsed but were reinduced to CR. Although no prophylactic central nervous system (CNS) therapy was given, only one patient has developed CNS involvement after diagnosis. Two girls became pregnant while on maintenance therapy. One delivered a normal, full-term infant; both she and the child are well 24 months later.

Adolescent↗
PubMed1977

Isolation of the glucuronic acid conjugate of n-hydroxy-4-aminobiphenyl from dog urine and its mutagenic activity.

The glucuronic acid conjugate of N-hydroxy-4-aminobiphenyl (NOH-4-ABP) has been isolated in relatively pure form from the urine of dogs given 4-aminobiphenyl, utilizing molecular size, ion exchange, adsorption, and partition chromatography. This conjugate is an active mutagen in Salmonella typhimurium strains TA1538 and TA98 but not in TA1535 or TA1537. NOH-4-ABP and 4-nitrosobiphenyl are also highly active in TA1538 and TA98 and inactive in TA1535 and TA1537. These observations support the concept that this conjugate is the water-soluble carrier that delivers the active metabolite to the bladder. A substance of identical chromatographic and spectral properties to the conjugate isolated from dog urine has been synthesized in low yield by the direct condensation of NOH-4-ABP with glucuronic acid. This substance yields NOH-4-ABP on dilute acid hydrolysis. Sodium (N-4-biphenylhydroxylamino-beta-D-glucopyranosid) uronate, the N-O-C isomer, was also synthesized. It was found to have differing chromatographic and chemical properties to the natural conjugate. This evidence suggests that the urinary conjugate is the compound in which conjugation has occurred with the nitrogen atom of the hydroxylamine group rather than the oxygen atom.

Aminobiphenyl Compounds↗
PubMed1976

Neutrophil oxidative metabolism in sickle cell disease.

Bacterial infections are the most frequent cause of death and an important factor of morbidity in sickle cell disease. A defect in oxidative metabolism of neutrophils from these patients has been reported as a possible cause for these infections. Since normal neutrophil functions are essential in the defense against bacteria, it seemed important to reassess the capacity of neutrophils from patients with sickle cell disease to undergo the metabolic events associated with phagocytic bactericidal activity. Accordingly, neutrophils from patients and controls were compared for their ability to reduce nitroblue tetrazolium dye, to activate the hexose monophosphate shunt, and to generate superoxide anion, hydrogen peroxide, and chemiluminescence. Patients' cells performed normally in each of these assays and, in addition, killed Staphylococcus aureus as well as did cells from controls. Thus, an abnormality of neutrophil oxidative metabolism cannot explain the propensity to bacterial infections in sickle cell disease.

Adolescent↗
PubMed1968

Leukocyte degranulation and vacuole formation in patients with chronic granulomatous disease of childhood.

A cellular defect associated with decreased bactericidal activity of the polymorphonuclear leukocyte has been found in a 2(1/2) yr old Negro boy with the typical clinical and pathological findings of chronic granulomatous disease. Unlike previously described patients his polymorphonuclear leukocytes were shown to undergo apparently normal degranulation and vacuole formation after phagocytosis. Metabolic studies of the leukocytes indicated a failure to increase oxygen consumption with phagocytosis or to reduce Nitroblue tetrazolium dye. These metabolic abnormalities are identical with those previously reported in patients with chronic granulomatous disease. Two additional patients with chronic granulomatous disease have also been found to have apparently adequate degranulation of polymorphonuclear leukocytes after phagocytosis. Our studies suggest that failure of degranulation may not be a necessary part of this functional leukocyte abnormality.

Child, Preschool↗
PubMedDate not supplied

Chronic nitric oxide inhibition as a model of hypertensive heart muscle disease.

We have compared the myocardial alterations in rats made hypertensive by the chronic inhibition of nitric oxide biosynthesis with those having renal hypertension (two kidney-one clip model). Male Wistar rats were chronically administered the nitric oxide synthase inhibitor N omega-nitro-L-arginine methyl ester (L-NAME) for 2, 4 and 8 weeks. Both groups initially developed a similar increase in blood pressure but only the 2K-1C rats developed myocardial hypertrophy after 2-4 weeks. L-NAME-treated animals developed a similar degree of hypertrophy following 8 weeks of treatment. As observed by light microscopy, the myocardial alterations in the latter animals consisted of extensive areas of fibrosis and myocardial necrosis, especially in regions of the subendocardium. The histological alterations induced by L-NAME were not caused by the accompanying hypertension, since the 2K-1C animals had a similar increase in arterial blood pressure without any significant alterations in the heart morphology. 2K-1C rats treated chronically with L-NAME behaved in a manner similar to the L-NAME-treated animals with regard to both the blood pressure increases and cardiac morphological alterations. Animals which received the inactive enantiomer D-NAME did not develop hypertension nor did they have any morphological abnormalities. Both the coronary flow and the contractile capacity of hearts isolated from rats treated with L-NAME for 8 weeks were impaired compared to control animals. These results indicate that the chronic inhibition of NO biosynthesis causes cardiac ischemia associated with a mechanical dysfunction that is unrelated to cardiac hypertrophy which is similar to those seen in some patients suffering from chronic arterial hypertension.

Analysis of Variance↗