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Biomedical subjects

D Lopez

Publications and source records attributed to D Lopez.

64 records · Page 4Linked to original sources
PubMed1976

Effect of megestrol acetate (Megace) on steroid metabolism and steroid-protein binding in the human prostate.

Megestrol acetate (Megace), an antiandrogen, was administered in a dosage of 80 mg daily to 6 patients with benign prostatic hypertrophy (BPH) for 4 to 25 days prior to transurethral resection of the prostate (TURP). Surgical tissue from drug-treated patients was compared to untreated controls in regard to: 1) the enzymatic reduction of testosterone (T) and dihydrotestosterone (DHT); 2) DHT binding to a cytosol receptor protein; 3) tissue levels of endogenous dihydrotestosterone and androstanediols (diols). When minced prostate was incubated with 3H-T and 14C-androstenedione for 1 h at 37 C, prostate 5alpha-reductase activity, measured as reduced products formed from substrate, decreased to 31% and 39%, respectively, of the control values. Prostate 3-oxido-reductase enzyme activity, measured as diols formed from 3H-DHT, was decreased to neglible values in Megace-treated patients compared to an 8.7% conversion to diols in controls. No 3H-DHT binding to a cytosol receptor protein could be demonstrated in 4 out of 5 prostates from Megace-treated patients, whereas the presence of such a receptor was noted in 14 out of 17 untreated controls. Endogenous DHT levels in Megace-treated patients averaged 1.1 ng/g (SE = 0.26), significantly less than the average of 3.9 ng/g (SE = 0.49) found in controls (P less than 0.001). No significant difference was noted in endogenous diols. In addition to these effects on tissue, Megace significantly decreased plasma levels of T, LH, and FSH at the end of the 4- to 25-day period; plasma prolactin levels did not change. Continued studies of Megace for the possible treatment of benign prostatic hypertrophy may be warranted since the drug appears to block several important biochemical steps which mediate the effects of androgen on the human prostate.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMedDate not supplied

Preliminary study of the reliability of assessment procedures for indications for chiropractic adjustments of the lumbar spine.

OBJECTIVE: To assess the intraexaminer and interexaminer reliability of clinicians trained in flexion-distraction technique to determine the need for chiropractic adjustment of each segment of the lumbar spine. DESIGN: This was an intraexaminer and interexaminer reliability study of commonly used chiropractic assessment procedures, including static and motion palpation and visual observation. SETTING: Chiropractic college; by four licensed chiropractors trained in flexion-distraction technique, two with more than 20 years' experience and two with 3 or fewer years' experience. SUBJECTS: Subjects were 18 volunteers; 16 were symptom free, and 2 had low back pain at the time the study was conducted. MAIN OUTCOME MEASURE: The kappa statistic was computed for all comparisons and interpreted in categories ranging from "poor" (<0.00) to "almost perfect" (>0.80). RESULTS: Intraexaminer reliability was greater than interexaminer reliability. For intraexaminer reliability there was considerable variation by segment and among the four examiners, but intraexaminer reliability appeared generally higher than interexaminer reliability. Overall, more subluxations were identified on the second examination than on the first. For interexaminer reliability, kappa scores were generally in the "poor" to "slight" categories. DISCUSSION: The results of this study, similar to those of other studies, indicate that even chiropractors trained in the same technique seem to show little consensus on the indications for the necessity to adjust specific segments of the spine. A more standardized assessment approach might be helpful in improving the reliability of diagnostic assessments.

Adult↗
PubMedDate not supplied

Image magnification in renal and superior mesenteric angiography: CT calculation and assessment of variables.

PURPOSE: To estimate the magnification that occurs in conventional renal and mesenteric angiography and to assess the influence of anatomic and technical variables. PATIENTS AND METHODS: Anticipated image magnification was derived solely from computed tomographic (CT) measurements obtained of 152 consecutive adult patients who underwent abdominal CT. Scans showed the distance from the origin and distal portions of both renal arteries to the anterior and posterior body surfaces, as well as the distance from the origin of the superior mesenteric artery to the lateral body surfaces. Assuming a 101.6-cm (40-inch) source-to-image receptor distance, the degree of magnification was calculated for posteroanterior, anteroposterior, and lateral radiographic imaging techniques. RESULTS: Calculated mean magnification for the proximal renal artery was 14.5% (range, 7.2%-25.8%) with posteroanterior imaging and 26.7% (range, 22.3%-36.7%) with anteroposterior imaging and a 10-cm-thick table. Mean magnification for the distal renal artery was 16.1% (range, 8.8%-25.3%) with posteroanterior imaging and 24.6% (range, 19.5%-36.4%) with anteroposterior imaging and a 10-cm-thick table. Magnification of the superior mesenteric artery was 17.8% (range, 12.5%-33.9%) with left lateral imaging. Regression analysis documented a linear relationship between percentage magnification and body diameter. CONCLUSION: Arterial location, imaging technique, and especially body habitus affect the degree of magnification in a predictable fashion.

Adolescent↗
PubMedDate not supplied

Asbestos bodies in normal lung of western Mediterranean populations with no occupational exposure to inorganic dust.

The aim of this study was to determine the following: (a) asbestos body count in lung tissue of different western Mediterranean populations; (b) the association, if any, of urban industrial residence with higher lung tissue asbestos exposure posed for lung cancer in our population. Lung-tissue samples were studied in three groups of subjects from the general population: (1) group A comprised 18 patients from Barcelona's urban industrial area (mean age = 62.2 y, standard deviation [SD] = 13.6); (2) group B comprised 16 patients who lived in a rural area of Albacete in the south of Spain (mean age = 62.2 y, SD = 13.7); and (3) group C comprised 8 patients who had been diagnosed with lung cancer, who lived in or near Barcelona, and who had never been exposed occupationally to asbestos (mean age = 62.1 y, SD = 7.4). A wet lung/dry lung weight ratio was determined. In group A, asbestos bodies were observed in 9 of 18 (50%) subjects, and asbestos bodies numbered 52.35 per g dry lung (SD = 101.72) (upper limit of normality [higher value] = 430.12 asbestos bodies per g dry lung). In group B, asbestos bodies were observed in 2 of 16 (12.5%) subjects, and asbestos bodies numbered 5.37 per g dry lung (SD = 8.79) (upper limit normality = 35.15 asbestos bodies per g dry lung). In group C, we observed asbestos bodies in 2 of 8 subjects (25.0%), and asbestos bodies numbered 20.59 per g dry weight (SD = 24.10).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Length of care in patients with severe burns with or without early enteral nutritional support. A retrospective study.

The possible influence of early enteral nutritional support on the length of care was explored retrospectively in 25 patients with burns greater than 20% total body surface area (TBSA). Patients were divided into two groups according to the time of their admission: group 1, from July 1986 to February 1987 (n = 12) and group 2, from July 1987 to January 1988 (n = 13). The only difference in treatment between the two groups was the start of early enteral nutritional support in group 2. Age, percent TBSA burned, surfaces of skin grafts, associated respiratory injury, and medical condition were identical in both groups. The following parameters were compared: lag time between hospital admission and the beginning of nutritional support, energy intake, nitrogen intake during the 4-week postadmission period, and length of care. A regression analysis including all patients was also performed to identify the factors associated with length of care. Lag time was shorter in group 2 than in group 1: 3 +/- 2 days versus 7 +/- 2 days (p less than 0.01). Group 2 received more energy than group 1 during the first 2 weeks after admission: 120 +/- 54 kj/kg/day versus 73 +/- 34 kj/kg/day (p less than 0.05) and 175 +/- 36 kj/kg/day versus 137 +/- 41 kj/kg/day (p less than 0.05) for the first and the second week, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMedDate not supplied

Patient self-management of continuous subcutaneous insulin infusion.

Continuous subcutaneous insulin infusion (CSII) is one of the ways to control blood glucose for prolonged periods. This study was undertaken to establish the long-term feasibility and efficacy of CSII with patient self-management. Patients were instructed to maintain their calorie and carbohydrate intake. Basal infusion of insulin, representing 50% of the total pre-CSII dose, was supplemented by boluses of insulin based on carbohydrate intake for each meal. With this type of regimen, blood glucose and M-values were easily normalized during the physician-directed periods. This study demonstrated that near-normalization of blood glucose, M-values, and glycosylated hemoglobin was maintained after a 1 1/2-yr period of patient self-management. We attributed this successful management in part to the protocol used, in which boluses were related solely to carbohydrate intake while basal insulin was adjusted according to fasting blood glucose. The chronic normalization of blood glucose resulted in improvement of platelet function as witnessed by responsiveness to antiaggregating (PGE1) and aggregating (epinephrine) agents. An improvement was noticed in doppler measurement of ankle-arm blood pressure and a near-normalization of nerve latency and conductivity was observed.

Adult↗
PubMedDate not supplied

Continuous subcutaneous insulin infusion (Mill-Hill Infuser) versus multiple injections (Medi-Jector) in the treatment of insulin-dependent diabetes mellitus and the effect of metabolic control on microangiopathy.

The present study was designed to compare continuous subcutaneous insulin infusion (CSII) using the Mill-Hill Infuser (Muirhead Medical Products Ltd., London, England) with multiple injections (MI) using the Medi-Jector (Derata Corporation, Minneapolis, Minnesota) in the treatment of insulin-dependent diabetes mellitus (IDDM), and to assess the effect of glucose control on diabetes complications. Twelve diabetic subjects were treated 3 mo with CSII and 3 mo with MI (bedtime ultralente and premeal boluses of regular insulin) in a randomized fashion. Prestudy preprandial/postprandial glucose levels were 147-215 mg/dl and improved to 108-138 mg/dl during CSII, and to 115-139 mg/dl during MI with glycosylated hemoglobin of 12.9%, 9.1%, and 8.7%, respectively. This improved glucose control with either CSII or MI was associated with an increase in sural nerve conductivity from 42.9 to 45 m/s and a decrease in proteinuria from 1.9 to 0.5 g/24 h. The 24-h insulin dose consisted of 45 U before the study, 44 U during CSII, and 56 U during MI. After the study, seven patients opted to continue with the Mill-Hill Infuser, and five with the Medi-Jector. We conclude the following: (1) treatment with both the Mill-Hill Infuser and the Medi-Jector was well accepted by the patients and resulted in similar improvement in measured blood glucose and glycosylated hemoglobin; (2) this improved metabolic control was associated with an increased nerve conductivity and a decreased protein excretion; and (3) MI required 20% more insulin than CSII to achieve similar glycemic control.

Adult↗
PubMedDate not supplied

Effects of epidermal growth factor and mitogenic pathway inhibitors on rat colon cancer proliferation in vitro.

The proliferative responses of two rat colon cancer cell lines (Per192NR and Per237) to concentrations of epidermal growth factor (EGF) were assessed alone, or in combination with calcium sequestration or inhibitors of protein kinase A, C (PKA and PKC). Up to 160nM of EGF stimulated cell proliferation in Per237 cells, but was ineffective in Per192NR cells. In both cell lines all inhibitors failed to alter basal proliferation. In Per192NR cells the combination of 5 to 20nM EGF and inhibitor resulted in a biphasic reduction in basal proliferation which was lost by 20nM. In the Per237 cells only 10nM EGF and PKA inhibitor reduced proliferation. Tumours derived from the same origin respond differently to EGF-induced mitogenesis.

Adenocarcinoma↗