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Biomedical subjects

I Rodriguez

Publications and source records attributed to I Rodriguez.

86 records · Page 5Linked to original sources
PubMed1990

Monoclonal antibodies to the VP6 of porcine subgroup I rotaviruses reactive with subgroup I and non-subgroup I non-subgroup II strains.

A panel of 10 monoclonal antibodies produced after immunization with two porcine subgroup I rotavirus strains (OSU and A46), and directed against the major inner capsid protein (VP6), fell into six patterns of reactivity when tested against a collection of human and animal group A rotavirus strains. Monoclonal antibodies of pattern I recognized all rotavirus strains. Antibodies of patterns 2 and 3 recognized all subgroup II strains and some, but not all, subgroup I strains. Pattern 4 antibodies identified all subgroup I strains and two strains (H2, equine; CC117, porcine) not reactive with reference subgroup monoclonal antibodies (strains non-I non-II). Pattern 5 antibody exhibited the same reactivity as pattern 4 except for not recognizing the non-I non-II equine strain. Pattern 6 antibodies reacted exclusively with subgroup I and non-I non-II rotaviruses of porcine origin. By competitive binding assays, monoclonal antibodies of patterns 4, 5 and 6 appeared to recognize a single antigenic site, which included at least three overlapping epitopes. In immunoblots all monoclonal antibodies, except one, recognized only the trimeric, but not the monomeric form of VP6.

Animals↗
PubMed1990

Trypanosoma cruzi infection in the Mexican state of Guerrero: a seroepidemiological (ELISA) survey of 20 communities.

The enzyme linked immunosorbent assay (ELISA) was used to analyse 4372 blood samples from residents of 978 households in 20 representative communities in the Mexican state of Guerrero. Seventy-five individuals had very high titres of antibodies against Trypanosoma cruzi. Samples with intermediate optical density values, despite overlapping values with several control positives on a single-well test, did not sustain their positivity at high dilutions. 'Intermediate positives' had a different distribution among the 20 communities to samples sustaining reactivity at high dilutions, indicating possible cross-reactivity with another infectious agent. The finding of seropositive children under the age of 10 years in the Costa Chica, Acapulco and the Tierra Caliente regions, with family clustering of putative cases, indicates that recent transmission must be considered. Very few people interviewed in the 20 communities knew the triatomine bug could transmit a disease.

Age Factors↗
PubMed1989

Evidence for the presence of specific binding sites for corticoids in mouse liver plasma membranes.

The specific binding of [3H]cortisol to plasma membranes purified from mouse liver, studied by the ultrafiltration method, shows the existence of specific binding sites for cortisol. The kinetic parameters of this binding are KD = 4.4 nM and Bmax = 685 fmol/mg protein in presence of 1 microM of corticosterone. With respect to the binding of 4 nM [3H]cortisol to the membrane, the affinities of the steroids decreased in the following order: deoxycorticosterone greater than corticosterone greater than progesterone greater than cortisol greater than prednisolone greater than testosterone greater than 20 beta-hydroxyprogesterone greater than cortisone. Estradiol, dexamethasone, ouabain and triamcinolone acetonide do not have affinity for this binding site. Neither Ca2+ nor Mg2+ affected the binding of [3H]cortisol to the plasma membranes. Likewise, the presence of agonists and antagonists of alpha and beta-adrenergic receptors did not modify the binding of [3H]cortisol. The results suggest that the plasma membrane binding site characterized is more specific for corticoids and is different from nuclear glucocorticoid and progesterone receptors.

Adrenal Cortex Hormones↗
PubMed1989

Evaluation of a latex agglutination test for Rickettsia conorii antibodies in seropositive patients.

A latex agglutination test for antibodies to Rickettsia conorii was compared with micro-immunofluorescence (the reference test for total antibodies); 179 sera were from 115 confirmed cases of Mediterranean Spotted Fever, and 101 were from pregnant women (control group) who had no detectable antibodies by the reference method. The micro-immunofluorescence test for specific IgM antibodies was used to clarify some discordant results. The agreement obtained between latex-R. conorii and micro-immunofluorescence was 95%. Sensitivity and specificity were 96% and 93% respectively. When micro-immunofluorescence results for specific IgM antibodies were included, these figures rose to 96 and 99%, and agreement was almost 97%. Latex agglutination is a simpler and more rapid technique than micro-immunofluorescence and is suitable for the screening as well as for the titration of R. conorii antibodies.

Antibodies, Bacterial↗
PubMed1984

Structures of the O-linked oligosaccharides of the major cell surface sialoglycoprotein of MAT-B1 and MAT-C1 ascites sublines of the 13762 rat mammary adenocarcinoma.

Structures of the principal O-glycosides from the major cell surface sialoglycoprotein (ASGP-1) of the MAT-B1 and MAT-C1 ascites sublines of the 13762 rat mammary adenocarcinoma have been determined. Oligosaccharitols were released by alkaline borohydride treatments of ASGP-1 and purified by gel filtration, DEAE-Sephadex ion exchange chromatography, and high performance liquid chromatography. On the basis of carbohydrate composition, methylation analysis, periodate oxidation, and exoglycosidase digestion, the five major oligosaccharides released by mild alkaline borohydride were assigned the following structures: Component II-3: (NeuAc alpha 2----3Gal beta 1----4GlcNAc beta 1----6)Ga 1 NAcOH(3----1 betaGa 1 3----2 alpha NeuAc) III-2a: (Ga 1 beta 1----4G1cNAc beta 1----6)Ga 1 NAcOH(3----1 beta Ga 1 3----2 alpha NeuAc) III-2c: (Ga 1 alpha 1----3Ga 1 beta 1----4G1cNAc beta 1----6) Ga 1 NAcOH(3----1 beta Ga 1 3----2 alpha NeuAc) IV-1a: (Ga 1 beta 1----4G 1 cNAc beta 1----6)Ga 1 NAcOH(3----1 beta Ga 1) IV-1c: (Ga 1 alpha 1----3Ga 1 beta 1----4G 1 cNAc beta 1----6) Ga 1 NAcOH(3----1 beta Ga 1) Fucosylated derivatives of III-2a, IV-1a, and IV-1c were found in smaller amounts with the fucose tentatively assigned to the 2-position of the lactosamine galactose. Components II-3, III-2a, and the fucosylated derivative of III-2A were found in both MAT-B1 and MAT-C1 sublines. The alpha-galactosides were found in detectable quantities only in subline MAT-B1. Oligosaccharides from MAT-C1 cells were enriched in sialic acid when compared to those from MAT-B1 cells. These results suggest that the 13762 ascites sublines, which bear different oligosaccharides, will provide models useful for the investigation of mechanisms regulating the expression of structures of the larger O-linked oligosaccharides.

Animals↗
PubMed1984

Pharmacodynamics of the initiation of antiarrhythmic therapy with lorcainide.

Lorcainide is an antiarrhythmic drug with unusual pharmacokinetics and an active metabolite, norlorcainide, which complicate oral drug loading. In order to characterize the accumulation of lorcainide and norlorcainide and to define the onset of antiarrhythmic action during lorcainide loading, 9 patients with frequent ventricular ectopic beats were studied. During lorcainide loading with 100 mg orally twice daily, frequent ambulatory electrocardiographic recordings were monitored and blood samples for drug concentrations were determined. There was a 10-fold range of intersubject variation in plasma concentrations. Despite a half-life of only 8.9 +/- 2.3 hours, lorcainide did not reach steady state until after 4.5 days of therapy. Norlorcainide had a half-life of 26.5 +/- 7.2 hours and was estimated to come to steady state after 7 to 10 days. There was considerable intersubject variation in time of onset of antiarrhythmic response (2 to more than 4.5 days) and a 4- to 5-fold range of intersubject variation in threshold therapeutic plasma concentration (lorcainide 40 to 200 ng/ml, norlorcainide 80 to 300 ng/ml). These observations suggest that lorcainide should be started at low doses and the dose should not be increased more frequently than once a week.

Administration, Oral↗
PubMed1984

Ultrastructural study of the keratinization process in different clinical types of oral leukoplakia.

The keratinization process has been investigated by ultrastructural methods in different clinical types of oral leukoplakia in 12 biopsy specimens from the buccal mucosa. Simple and verrucous clinical types of oral leukoplakia showed the presence of well-defined keratohyaline granules and the formation of tonofibrils. Erosive leukoplakias showed a lack of keratohyaline granules and a decreased aggregation of tonofilaments; in the upper cell layers dark and clear cells were found. The formation of a granular layer occurred in connection with orthokeratosis, mainly in simple and verrucous leukoplakias; erosive leukoplakias showed no corneal layer.

Biopsy↗
PubMed1982

[Male XX-syndrome].

Described in this paper is a patient, aged eleven years and eight months, with micropenis, dorsal prepuce, and rugous, partially bifid scrotum. FSH and LH values below normal were obtained from hormonal investigation. LH-RH stimulation was followed by retarded FSH response of moderate intensity, while the LH profile was moderately strong. Cytogenetic tests revealed the presence of 25 per cent of female sex chromatin. The karyotype was 46 XX. The patient did not have internal female genital organs, and his gonads were of testicular appearance. Histologically, both testicles exhibited tubules with primitive germinal cells and Sertoli cells. An inconspicuous number of Leydig cells was recorded from the interstitium.

Child↗
PubMed1981

Keratotic lesions of the oral epithelium.

Glycogen in the epithelium is interpreted as a sign of cell activity; its accumulation seems to take place gradually during cell migration. The oxido-reductase and hydrolytic enzyme-groups represent a sensitive indicator of changes in cell metabolism. The occurrence and intensity of glycogen, lactic and succinic dehydrogenases, NAD-cytochrome-c-reductase, alkaline and acid phosphatases were studied in 20 biopsy materials obtained from patients with keratotic buccal lesions. The results were compared with 20 biopsies from healthy oral mucosa. Variations were found in the localization and amount of glycogen, but no significant difference could be observed in the intensity of the oxido-reductase enzymes and alkaline phosphatase reactions. Acid phosphatase showed increased reactivity in most superficial layers of the keratinized epithelium.

Acid Phosphatase↗
PubMed1979

Metabolic changes in red blood cells in malignant lymphomas.

Serum copper levels (SCL) which are concomitantly related to red blood cell free copper are significantly increased in some malignant lymphomas in the phase of activity. This results in a profound inhibition of red cell key glycolytic enzymes, hexokinase (Hx) being the most sensitive. Fifteen patients (eight with Hodgkin's disease and seven with non-Hodgkin's lymphoma) were studied for serum and red cell copper concentrations and Hx activity. The mean red cell life span was determined using 51Cr labelled red cells. The resulting data shows that in active disease an increase in SCL was associated with a decrease in Hx activity and a shortened red cell survival. In these cases there was no evidence of autoimmune phenomena or of direct bone marrow involvement by the disease. It is suggested that the increase in copper levels results in a shortened red cell life span through a copper-induced inhibition of red cell Hx.

Copper↗
PubMedDate not supplied

Investigation of risk factors for porcine Taenia solium cysticercosis: a multiple regression analysis of a cross-sectional study in the Yucatan Peninsula, Mexico.

A cross-sectional survey for seropositivity to cysticercosis of pigs in the Yucatan Peninsula, Mexico, was carried out in 1996 together with a standardized questionnaire on predetermined individual pig and household risk factors for porcine infection. Serum samples from 697 pigs were analysed by immunoblot for antibodies to Taenia solium cysticercosis and questionnaires from 227 households in 18 villages were collected. All the data were analysed using multivariate analytical techniques taking household clustering into account. The overall porcine seroprevalence in the area was found to be 29%. The most important risk factors for seropositivity in pigs were presence versus absence of a toilet (adjusted odds ratio [adj. OR] 2.37, P = 0.005), crowded households (adj. OR 1.75, P = 0.034) and both corralling (adj. OR 2.14, P = 0.017) and letting pigs loose (adj. OR 2.32, P = 0.035) versus tying them up. There was evidence of clustering at household level and that possible risk factors at municipal or village level may also interact with higher risk management practices such as allowing pigs to run loose.

Animal Husbandry↗
PubMedDate not supplied

Peritoneal sodium mass removal in continuous ambulatory peritoneal dialysis and automated peritoneal dialysis: influence on blood pressure control.

BACKGROUND/AIM: Sodium and water retention is common in peritoneal dialysis patients and contributes to cardiovascular disease. As peritoneal sodium removal depends partly on dwell time, and automated peritoneal dialysis (APD) often uses short dwell time exchanges, the aim of this study was to compare the 24-hour peritoneal sodium removal in APD and standard continuous ambulatory peritoneal dialysis (CAPD) patients and to analyze its possible influence on blood pressure control. METHODS: A total of 53 sodium balance studies (30 in APD and 23 in CAPD) were performed in 36 stable peritoneal dialysis patients. The 24-hour net removal of sodium was calculated as follows: M = ViCi - VdCd, where Vd is the 24-hour drained volume, Cd is the solute sodium concentration in Vd, Vi is the amount of solution used during a 24-hour period, and Ci is the sodium concentration in Vi. Peritoneal sodium removal was compared between APD and CAPD patients. Residual renal function, serum sodium concentration, daily urinary sodium losses, weekly peritoneal Kt/V and creatinine clearance, 4-hour dialysate/plasma creatinine ratio, proportion of hypertonic solutions, net ultrafiltration, systolic and diastolic blood pressures, and need for antihypertensive therapy were also compared between the groups. RESULTS: Peritoneal sodium removal was higher (p < 0.001) in CAPD than in APD patients. There were no significant differences in residual renal function, serum sodium concentration, urinary sodium losses, peritoneal urea or creatinine clearances, 4-hour dialysate/plasma creatinine ratio, or proportion of hypertonic solutions between groups. The net ultrafiltration was higher in CAPD patients and correlated strongly (r = 0.82; p < 0.001) with peritoneal sodium removal. In APD patients, peritoneal sodium removal increased significantly only in those patients with a second daytime exchange. The systolic blood pressure was higher (p < 0.05) in APD patients, and the proportion of patients with antihypertensive therapy was also higher in APD patients, although no significant relationship between blood pressure values and amount of peritoneal sodium removal was found. CONCLUSIONS: The 24-hour sodium removal is higher in CAPD than in APD patients, and there is a trend towards better hypertension control in CAPD patients. As hypertension control and volume status are important indices of peritoneal dialysis adequacy, our results have to be considered in the choice of the peritoneal dialysis modality.

Adult↗