Search PubMed⌕ Search

Biomedical subjects

R Lopez

Publications and source records attributed to R Lopez.

At least 181 records · Page 10Linked to original sources
PubMed1981

High incidence and characterization of glucocorticoid receptors in human malignant melanoma.

The glucocorticoid receptor was characterized in biopsy samples from patients with recurrent malignant melanoma. Glucocorticoid receptors were measured by the charcoal-adsorption technique. Tumor cytosol from approximately 86% (25/29) of the patients contained large quantities of receptors (20-324 fmol/mg protein). The dissociation constant of this cytoplasmic receptor was determined to be 2-22 nM. This binding component sedimented at 7.1S on sucrose gradients of low ionic strength and dissociated into lower molecular weight components that sedimented at 4.4S on sucrose gradients of high ionic strength. Receptor binding was specific for glucocorticoids. Although progestins competed well for the binding that is typical for glycocorticoid receptor as reported in the literature, other steroids, e.g., 17 beta-estradiol and 5 alpha-dihydrotestosterone, were only weak competitors. These results demonstrated that this neoplasm contains large quantities of glucocorticoid receptors that are similar in their physicochemical characteristics to those found in normal tissues. This finding in human melanoma biopsy specimens may be of therapeutic value in the management of patients with malignant melanoma.

Adult↗
PubMed1980

The role of serum myoglobin in the detection and measurement of myocardial infarction.

The use of serum myoglobin determinations in the diagnosis and quantitation of acute myocardial infarction was studied in 53 patients. Serial blood samples collected for the first 72 h after pain were analysed for serum myoglobin using a radioimmunoassay procedure. Samples were also assayed for serum creatine kinase (CK) and its myocardial isoenzyme CK-MB, aspartate aminotransferase (AST) and alpha-hydroxybutyrate dehydrogenase (alpha HBDH). Analysis of first and second samples obtained at mean times of 7.6 and 10.7 h respectively after pain produced the following detection rate: serum myoglobin 85% and 98%; serum CK 71% and 85%; serum AST 58% and 81%; serum CK-MB 29% and 60%; serum alpha HBDH 23% and 33% respectively. Total CK-MB and myoglobin release from damaged myocardium were calculated using the method of Norris et al. [16]. A significant correlation was obtained between infarct size calculated from CK-MB and myoglobin in the whole group (n = 29, r = 0.71, p < 0.001). The correlation was even more significant for smaller infarcts with CK-MB release < 220 U/l (n = 13, r = 0.92, p < 0.001).

Adult↗
PubMed1980

Treatment of adult neuroblastoma.

Twelve patients, all over 17 years of age, with adult neuroblastomas, an entity recently described, were seen at Roswell Park Memorial Institute for the period from 1950 to 1977. Four of these patients who were treated by multimodality therapy constitute the bulk of this report. One patient had a complete response and showed no evidence of disease 23 months after treatment with surgery and combination chemotherapy (CYVADIC); she also had maturation of established metastases. Another patient remained stable for 22 months after treatment with combination chemotherapy. These results indicate that chemotherapy may be effective treating adult neuroblastoma patients as complete remissions are achieved and survival times prolonged.

Adolescent↗
PubMed1980

Intraarterial adriamycin in the treatment of soft tissue sarcomas.

Ten patients with extremity sarcomas adriamycin 60 mg/M2 into the artery supplying the area of tumor. There were minimal local side effects consisting of occasional local erythema or slight transitory pain. Nine of these patients had subsequent surgery, and an average 32.86% histologic tumor necrosis was recorded in the peripherally viable areas of seven patients with residual tumor, compared to a 5.71% necrosis recorded in the biopsy sections (P value less than 0.01).

Adult↗
PubMed1980

Riboflavin deficiency in an adolescent population in New York City.

An adolescent population ranging in age from 13 to 19 years and of a low socioeconomic status in New York City was surveyed for riboflavin deficiency. Deficiency was determined from estimation of erythrocyte glutathione reductase activity, an accurate reflector of riboflavin nutritional status. The overall prevalence of deficiency among those not on vitamin supplements was 26.6%. The prevalence did not depend on sex or age. There was a correlation between milk consumption and riboflavin nutritional status. The prevalence was highest among those consuming less than 1 cup/week and least among those taking 3 or more cups a day. The latter group was comparable in this respect to those receiving daily vitamin supplements. Adolescents are at a high risk for nutritional deficiencies because of their notoriously poor dietary habits, and the estimation of riboflavin deficiency may be an indicator of overall nutritional status.

Adolescent↗
PubMed1980

Heart rate and ectopic prematurity in relation to sustained ventricular arrhythmias.

Forty-four patients with acute myocardial infarction were studied using 24-hour electrocardiographic monitoring. A linear correlation has been shown to exist between heart rate preceding accelerated idioventricular rhythm and ventricular tachycardia and the rates of these. The prematurity index was found to be inversely related to the preceding heart rate and also to the rate of accelerated idioventricular rhythm or ventricular tachycardia. Faster heart rates preceded extrasystoles with shorter prematurity indices and a significant inverse correlation was observed between preceding heart rate and prematurity index. Patients developing ventricular tachycardia had more frequent isolated ventricular extrasystoles and faster heart rates preceding the episode as compared with patients not showing ventricular tachycardia. No association was observed between ventricular tachycardia and accelerated idioventricular rhythm. All four patients developing ventricular fibrillation showed preceding ventricular tachycardia, with three of these patients demonstrating faster rates of ventricular tachycardia (greater than 170/min) and shorter prematurity indices (less than 0.80) than patients without ventricular fibrillation. Heart rate may influence the severity of ventricular arrbythmia; the prematurity of an extrasystole is of importance in patients developing accelered idioventricular rhythm or ventricular tachycardia.

Arrhythmias, Cardiac↗
PubMed1980

Ultrasonic features and radionuclide correlation in liver cell adenoma and focal nodular hyperlasia.

Ultrasonic features of three cases of liver cell adenoma (LCA) and two cases of focal nodular hyperplasia (FNH) are presented. These tumors have similar sonographic appearances presenting either as solid masses or containing sonolucent areas due to hemorrhage or necrosis. Although these ultrasonic features in patients with an area of decreased activity on 99mTc-sulfur colloid (Tc-SC) liver scans are not specific for LCA or FNH, such findings in the appropriate clinical setting are suggestive of these lesions. The combination of a solid mass on ultrasonography and a normal Tc-SC radioisotope liver study may be relatively specific for uncomplicated FNH.

Adult↗
PubMed1979

Effect of atenolol on recovery of the electrocardiographic signs of myocardial infarction.

The most notable changes in the 35-lead precordial electrocardiogram in 22 subjects in the first 6--12 months after acute myocardial infarction were a reduction in the amplitude of Q waves and a significant increase in the amplitude of the R waves. Patients who, in a random trial, had been given 100 mg atenolol daily from admission showed a significantly greater recovery in R-wave amplitude and decrease in Q waves than patients given placebo. It is concluded that atenolol improves the recovery of the electrocardiographic signs of myocardial infarction.

Acute Disease↗
PubMed1979

Tumor cell karyotypes in malignant melanoma.

Fifteen malignant melanomas were subjected to chromosomal analysis, in order to determine whether the number of chromosomes in a tumor cell could be correlated to a clinical prognosis. The protocol involved a direct technique which utilized a Colcemid blockade of spindle formation in mitosis to allow study of metaphase chromosomes. The direct method was chosen to reveal chromosome changes in the tumor cell in situ rather than changes in the cultured cell. Two tumors yielded chromosome spreads which could be counted and correlated with a clinical prognosis. Failure to obtain other adequate chromosome spreads were accounted for by the presence of tissue necrosis and the absence of viable tumor cells.

Adult↗
PubMed1979

Extraosseous osteogenic sarcoma: case report.

Extraosseous osteogenic sarcoma is a highly malignant tumor, and in order to improve the chances of survival of those who have it, aggressive surgical treatment, including major amputations, should be performed. Based on the results obtained in the treatment of its osseous counterpart, the use of adjuvant chemotherapy is strongly recommended. Evaluation should not be done because it is usually followed by local recurrence.

Adult↗
PubMed1979

Orthostatic hypertension.

A 40 year old man was found to have marked hypertension when he was in the upright position with normal pressures when he was supine. Investigations disclosed normal catecholamine and renin levels. The baroreceptor reflex was somewhat depressed. The mechanism of this orthostatic hypertension is not known. The condition has not been reported previously.

Adult↗
PubMed1979

Technic of resection of mesenteric tumors.

In the resection of mesenteric tumors or primary malignant lesions of the small bowel, exposure of the superior mesenteric vessels is important. This is the necessary criterion of resectability and the condition of obtaining maximal margins in the lymphatic drainage area. It also helps avoid unnecessary sacrifice of branches and tributaries to the superior mesenteric vessels from uninvolved portions of the bowel.

Humans↗
PubMed1979

Feasibility of integration of modalities in melanomas and sarcomas.

Chemotherapy was administered in the immediate postoperative period to seventy patients (52 with melanomas and 18 with sarcomas) after a total of eighty-seven major operations, with no morbidity or mortality traceable to the chemotherapy. There was no apparent interference with wound healing or what would be considered a normal postoperative course. Fourteen of these patients (5 with melanomas and 9 with sarcomas) received a combination of radiation anc chemotherapy initiated in the postoperative period, and it was tolerated well. This combination appears to be safe, provided the field of radiation is not so large that is may add significantly to the myelosuppressive effect of chemotherapy and the dosage of concomitantly administered radiopotentiating agent(s) is reduced. Sixteen patients had Bacillus Calmette-Gúerin (BCG) immunotherapy in the immediate postoperative period without complications. This policy of a tight interweaving of modalities is safe, has the theoretic advantage of an earlier concerted attack on microscopic residual tumor, and appears particularly promising in sarcomas.

BCG Vaccine↗