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Biomedical subjects

J L Rodríguez

Publications and source records attributed to J L Rodríguez.

At least 19 recordsLinked to original sources
PubMed2006

[Optic neuritis after meningococcal vaccination].

CASE REPORT: We report the case of a 13 year-old male with bilateral optic neuritis after meningococcal C vaccination. He was treated with intravenous corticosteroids, but only showed visual recovery in one eye. A significant limitation of his sharp vision remained in his other eye. DISCUSSION: There have been no previously reported cases of optic neuritis after meningococcal C vaccination and for this reason we have reported this case. It is not possible, however, to exclude some other factor in the etiology of the optic neuritis, but the temporal relationship between the neuritis and the vaccination suggests this was the cause.

Adolescent↗
PubMed2000

Nicotine for Alzheimer's disease.

BACKGROUND: Nicotine is a cholinergic agonist that acts, not only post-synaptically, but also releases pre-synaptic acetylcholine, and in animal models has been shown to reverse spatial memory decline in rats with lesion in the medial septal nucleus and to show recovery on memory in aged monkeys. Nicotine also has effects on other transmitters like serotonin (5HT), dopamine, or GABA. On the other hand, because nicotine has serious adverse effects, especially concerning cardiovascular risks in elderly people, and also on sleep and behavior, there are several important reasons to conduct a systematic review to assess the clinical efficacy and safety of nicotine in patients with AD. OBJECTIVES: The aim of this review is to determine whether there is evidence of beneficial effect, and to assess its safety profile, when nicotine is used for Alzheimer's disease. SEARCH STRATEGY: The Cochrane Controlled Trials Register (Issue 2, 99) was searched using the terms nicotin* and alzheimer*. Three references to trials were deemed suitable for inclusion but are awaiting consideration while the investigators are contacted. SELECTION CRITERIA: All unconfounded, double-blind, randomized trials in which treatment with nicotine patches or administration of nicotine intravenously was administered for more than a day and compared to placebo in people with Alzheimer's disease. DATA COLLECTION AND ANALYSIS: As no trials were suitable for inclusion, no data have been extracted or pooled in a meta-analysis. One trial is awaiting consideration, and if included in an update of this review, any available data will be incorporated. MAIN RESULTS: The poor quality of the trials did not allow any synthesis of results across studies. However, the data available in trials considered are compatible with nicotine producing harm, no change or improvement. REVIEWER'S CONCLUSIONS: This review is not able to provide reliable evidence that nicotine is a useful treatment for Alzheimer's disease.

Alzheimer Disease↗
PubMed2000

DNA methylation and histone acetylation of rat methionine adenosyltransferase 1A and 2A genes is tissue-specific.

Methionine adenosyltransferase (MAT) catalyzes the biosynthesis of S-adenosylmethionine (AdoMet). In mammals MAT activity derives from two separate genes which display a tissue-specific pattern of expression. While MAT1A is expressed only in the adult liver, MAT2A is expressed in non-hepatic tissues. The mechanisms behind the selective expression of these two genes are not fully understood. In the present report we have evaluated MAT1A and MAT2A methylation in liver and in other tissues, such as kidney, by methylation-sensitive restriction enzyme digestion of genomic DNA. Our data indicate that MAT1A is hypomethylated in liver and hypermethylated in non-expressing tissues. The opposite situation is found for MAT2A. Additionally, histones associated to MAT1A and MAT2A genes showed enhanced levels of acetylation in expressing tissues (two-fold for MAT1A and 3.5-fold for MAT2A liver and kidney respectively). These observations support a role for chromatin structure and its modification in the tissue-specific expression of both MAT genes.

Acetylation↗
PubMed2000

Total plasma homocysteine concentrations in Puerto Rican patients with presumptive atherosclerotic coronary disease.

BACKGROUND: In Puerto Rico, it has been established that although coronary heart disease is the leading cause of death, the population has a lower incidence of coronary disease than the continental United States. In addition, the severity of the disease is less aggressive in terms of a lower incidence of ventricular tachycardia and sudden death. A factor in the lower incidence of coronary disease in Puerto Rico could be a lower total plasma homocysteine concentration (tHcys) in our population. METHODS: We randomly measured tHcys concentrations in seventy-two Hispanic patients who were hospitalized for coronary angiography at the Cardiovascular Center of Puerto Rico and the Caribbean (UPR Division). RESULTS: The mean tHCys concentration in our patient population is similar than that reported for the Framingham study when adjusted by age (11.2 mumol/L vs. 11.8 mumol/L). In the Puerto Rican population, males had a higher tHcys concentration than females but this difference was not statistically significant (10.9 mumol/L vs. 9.4 mumol/L, p = 0.09). In addition, we did not see an increase of tHcys concentrations in diabetic patients when compared with nondiabetics (10.1 mumol/L vs. 10.3 mumol/L, p = 0.73). Neither we saw a direct correlation between tHcys concentrations and atherosclerosis as measured by coronary angiography (normal = 10.9 mumol/L, mild = 8.6 mumol/L, moderate = 10.9 mumol/L, severe = 10.5 mumol/L; ANOVA = 0.29). CONCLUSIONS: These results suggest that tHcys concentration is not a good predictor of atherosclerotic coronary disease in our patient population.

Angiography↗
PubMed2000

[Epidemiologic study of infection by hepatitis C virus in a hemodialysis unit].

OBJECTIVE: To analyze the prevalence of infection, the frequency of HCV genotypes and the epidemiology characteristics among the patients in hemodialysis treatment in one 25 years old hospital hemodialysis center and one 15 years old secondary unit by a transversal cross-section study in 1998. PATIENTS AND METHODS: 171 hemodialyzed-patients were studied. Patients sera were analyzed by the presence of HCV antibodies anti-VHC by a enzymoimmunoassay (Abbott Cientifica) and the presence of antibodies was confirmed by a line immunoassay (Inno-LIA HCV AbIII) and by the presence of VHC-RNA by reverse transcriptase PCR (Cobas Amplicor HCV). Genotypes were determinate by reverse hybridization (Inno-LIA HCV III). RESULTS: Fifty (29.2%) of the patients were HCV antibody positive. Forty-five (26.3%) were HCV-RNA positive, all of them with antibodies positive. The distribution of genotypes was: 1b, 34 (75.5%); 4f, 4 (8.9%); 1a, 3 (6.7%); 1, 3 (6.7%) and 1 case could not be typed (2.2%). In 14 patients (28.0%), seroconversions were documented Twenty-one patients (42.0%) were diagnosed when the routine tests were available and 15 patients (30.0%) were diagnosed pre-dialysis. The multivariate analysis showed that the risk of HCV infection was greater for patients who had been more 8 years on dialysis (OR: 6.22; 95% CI: 1.24-31.07). CONCLUSIONS: Data presented indicate that the prevalence of HCV infections in our hemodialysis units and the number of seroconversions were high and the HCV subtype 1b was more frequent; because of this, the screening by both serological and molecular methods is necessary, at least twice a year, to identify all the infected patients. Besides, we think that is necessary to increase the control of the completion of the Universal Precautions.

Cross-Sectional Studies↗
PubMed1999

Systemic lupus erythematosus in three ethnic groups. V. Acculturation, health-related attitudes and behaviors, and disease activity in Hispanic patients from the LUMINA cohort. LUMINA Study Group. Lupus in Minority Populations, Nature versus Nurture.

OBJECTIVE: To assess the relationship between acculturation and clinical, socioeconomic-demographic, and behavioral/psychosocial features in Hispanic patients with systemic lupus erythematosus (SLE) from the LUMINA (Lupus in Minority Populations, Nature versus Nurture) cohort. METHODS: An empirically derived questionnaire was administered to 67 Mexican American SLE patients participating in a longitudinal study of outcome. This questionnaire inquired about place of birth, upbringing and length of stay in the United States, language (proficiency, usage, and preferences; English/bilingual versus Spanish), type of neighborhood, self-identity, and social interactions. Responses to this questionnaire and an informal interaction with a single bilingual, bicultural Mexican American research assistant were used to generate a score on a 10-cm anchored visual analog scale (VAS) (0 = no acculturation and 10 = maximum acculturation). The responses to the questionnaire were then quantified and scored by a physician who was unaware of the VAS. A composite score was then obtained utilizing 4 of the 6 components of the instrument. The VAS was found to have adequate sensitivity (91%), specificity (88%), and overall predictive value (89%) when the composite score was used as the validity criterion. Therefore, the VAS was used in all subsequent analyses; the median in this VAS separated patients into high and low acculturation groups. The relationship between acculturation and sociodemographic, behavioral/psychosocial (social support, abnormal illness-related behaviors, and helplessness) and clinical variables (disease duration, onset type, number of American College of Rheumatology criteria met, disease activity, and damage) at study entry was then explored. RESULTS: Patients in the low acculturation group had fewer years of education, were less likely to have private health insurance, and had less social support as compared with those in the high acculturation group; they also exhibited less disease activity as determined by the overall physician and patient global assessments of the Systemic Lupus Activity Measure. Abnormal illness-related behaviors and helplessness were not increased in the low acculturation group. CONCLUSIONS: Low levels of acculturation were associated with indicators of low socioeconomic status, but also with less disease activity at enrollment into LUMINA; they were, however, not associated with more abnormal illness-related behaviors or with helplessness, as measured in this study. The possible impact of acculturation and of its mediators in the course and outcome of SLE among Hispanic patients needs to be determined longitudinally.

Acculturation↗
PubMed1999

Biochemical liver abnormalities in Turner's syndrome.

BACKGROUND: Turner's syndrome is a chromosomal abnormality (45X0) which may be associated with various autoimmune disorders and disease conditions; however, association with liver pathology has rarely been reported. OBJECTIVES: The aim of this work was to assess liver function abnormalities in a group of adult patients with Turner's syndrome. DESIGN AND METHODS: Liver function tests were performed in 16 women with Turner's syndrome all of whom had been previously treated with oestrogens. Patients with liver abnormalities were further studied with hepatic ultrasonography, serological markers of viral hepatitis and autoantibody determinations. RESULTS: Seven women (43.7%) presented with asymptomatic liver cholestasis; these patients were older than those with normal biochemical values (33.4+/-5.2 vs 24.7+/-5.7 years, P<0.05). Liver function abnormalities appeared 7.8+/-4.9 years after starting oestrogen therapy; however, no improvement of liver function was observed 20+/-17.7 months after stopping treatment. All of these women were anti-HCV and HBsAg negative, and autoimmune hepatitis was ruled out in all cases. Liver ultrasound only disclosed homogeneous liver enlargement in one case and cholelithiasis without bile duct abnormalities in another. Four patients underwent a percutaneous liver biopsy of which two were normal and two showed minimal non-specific changes. CONCLUSIONS: The incidence of biochemical liver cholestasis in this group of patients with Turner's syndrome is high. Oestrogen therapy and autoimmune disorders do not seem to be the responsible causes. It appears that this is a benign condition which does not seem to reflect any substantial liver dysfunction. The aetiology remains uncertain.

Adult↗
PubMed1999

Plasma glutathione concentrations in non-infected infants born from HIV-infected mothers: developmental profile.

Glutathione (GSH) is the primary antioxidant in humans. Oxidative cellular injury is postulated to be centrally involved in diverse processes including aging, cancer, cardiovascular disease, and Human Immunodeficiency Virus (HIV) disease progression. Normal plasma GSH concentrations have been well characterized in healthy children and adults, but not during infant development. The objectives of this study were to: a) measure plasma GSH concentrations in non-infected infants born from HIV-infected mothers, to b) assess the developmental variations with age and gender, and c) evaluate for possible associations with growth, anemia, and other maternal and infant variables. One hundred and seventy (170) plasma samples from 44 HIV-uninfected infants (birth to 18 mos.) born to HIV-infected mothers from the Women and Infant Transmission Study (Puerto Rico site) were analyzed. The total plasma GSH geometric mean concentration for all samples analyzed was 1.94 (1.06) mumoles/L. A developmental effect of age was seen with lower concentrations in younger infants (0-2 months) than in older infants 4-18 months. There was no significant effect of gender, anemia, zidovudine exposure, maternal age, maternal CD4 cell percent, or infant growth, although a trend towards increasing GSH concentration was seen with increasing weight for height z-score. These findings have multiple clinical ramifications including prediction of capacity to detoxify oxidants at different ages, and partial explanation for the increased viral loads seen in HIV-infected infants.

Adult↗
PubMed1998

Purification of a novel isoform of the regulatory subunit of cAMP-dependent protein kinase from the bivalve mollusk Mytilus galloprovincialis.

Cytosolic extracts from the posterior adductor muscle of the bivalve mollusk Mytilus galloprovincialis contain significant amounts of both cGMP-binding and cGMP-stimulated protein kinase activities. However, photoaffinity labeling with 8-azido-[32P]cGMP revealed only a major cGMP-binding protein with an apparent molecular mass of 54 kDa (p54), lacking protein kinase activity itself. Instead, the purified and cGMP-free p54 protein has the ability to inhibit a mussel protein kinase homologous to the mammalian cAMP-dependent protein kinase (cAPK) catalytic subunit, the inhibition being relieved by cAMP or cGMP, which suggests that it can act as a regulatory subunit of cAPK. However, p54 failed to be recognized by a specific antibody against the regulatory subunit (type RII) previously isolated from mussel. Therefore, p54 must be a novel isoform of cAPK regulatory subunit that seems to have high affinity for both cGMP and cAMP.

Animals↗
PubMed1998

Field studies and cost-effectiveness analysis of vaccination with Gavac against the cattle tick Boophilus microplus.

The control of tick infestations and the transmission of tick-borne diseases remains a challenge for the cattle industry in tropical and subtropical areas of the world. Traditional control methods have been only partially successful and the parasites continue to result in significant losses for the cattle industry. Recently, vaccines containing the recombinant Boophilus microplus gut antigen Bm86 have been developed. These vaccines have been shown to control tick infestations in the field. However, extensive field studies investigating the efficacy and cost-effectiveness of vaccination have not been reported and are needed to appraise the effect of this new approach for tick control. Here is reported the results of the application of Gavac in a field trial including more than 260,000 animals in Cuba. In this study the correlation between the antibody response to vaccination and the effect on ticks fertility is determined. Physiological status of the animals was found to affect the primary response to vaccination but not the antibody titers after revaccination. A cost-effectiveness analysis showed a 60% reduction in the number acaricide treatments, together with the control of tick infestations and transmission of babesiosis, which resulted in savings of $23.4 animal-1 year-1. These results clearly demonstrate the advantage of vaccination and support the application of Gavac for tick control.

Animals↗
PubMed1998

A pathological and immunohistochemical study of goat kids undergoing septicaemic disease caused by Mycoplasma capricolum subsp. capricolum, Mycoplasma mycoides subsp. capri and Mycoplasma mycoides subsp. mycoides (large colony type).

This paper studies the pathological and immunohistochemical findings in 12 kids experimentally infected with Mycoplasma capricolum subsp. capricolum (Mcc), M. mycoides subsp. capri (Mmc) and M. mycoides subsp. mycoides (large colony type), (MmmLC). For the demonstration of Mcc, Mmc and MmmLC antigens an immunoperoxidase technique based on the labelled streptavidin biotin method was used in the 12 kids inoculated with mycoplasmas and the three control kids inoculated with mycoplasma medium. All 12 kids, inoculated by different routes, developed subcutaneous swelling at the point of inoculation and terminated in fatal septicaemia from 1 to 5 days post inoculation. The histopathological findings consisted of cellulitis at the point of inoculation, acute diffuse interstitial pneumonia, arthritis and multifocal necrotic purulent splenitis in some kids. The Mcc, Mmc and MmmLC antigens were detected immunohistochemically in all kids with specific punctiform labelling inside the cytoplasm of the leucocytes or extracellularly at the inoculation point, respiratory airways, spleen, liver, joints, tonsils and lymph nodes. The results obtained in this study showed that the inoculation of these mycoplasmas by parenteral routes caused mycoplasmaemia. Moreover, the immunohistochemical results appear fully to confirm that the mycoplasmas were the cause of the death of the kids because of a septicaemic state.

Animals↗
PubMed1998

Gastric cryptosporidiosis in a wild frilled lizard from Australia.

An adult male frilled lizard (Chlamydosaurus kingi) was found dead in Northern Territory (Australia). On physical examination it was found to be severely emaciated. At necropsy the stomach was found to be firm with mild thickening of the gastric mucosa. Gastric rugae were prominent and the mucosa was red with a thin layer of dark red mucus on its surface. Light microscopic examination revealed a mild diffuse gastritis with infiltration of the lamina propria by lymphocytes, plasma cells, and heterophils. Large numbers of small, round amphophilic to basophilic (2 to 4 microns in diameter) organisms morphologically consistent with cryptosporidia were seen on the surface of the mucosal epithelium and free in the gastric lumen. The gastric lesions seen in this frilled lizard did not involve atrophy, as previously described in lizards with gastric cryptosporidiosis, and were similar to those described in snakes. The possibility that more than one species of Cryptosporidium parasitizes reptiles could explain the different lesions. This is the first report of cryptosporidiosis in a frilled lizard.

Animals↗
PubMed1997

Relationship between microstructure and ductility of investment cast ASTM F-75 implant alloy.

Hip replacement implants fabricated using the ASTM F-75 alloy sometimes fail in a sudden catastrophic way. In general, fractures start at microstructural defects subjected to stress-corrosion under chemical attack by body fluids. In this paper the results of a study on the effect of casting parameters on the microstructure of ASTM F-75 are presented. The preheating mold temperature and the liquid temperature were varied between 900 and 1000 degrees C, and 1410 and 1470 degrees C, respectively. Optimum static strength and ductility were obtained when shrinkage microporosity and the volume fraction of M23C6 "eutectic" carbides precipitated at grain boundaries were minimized by increasing the preheating mold temperature to 1000 degrees C and by using intermediate pouring temperatures of 1455 degrees C. Under these casting conditions, however, the solidification rates are low, leading to large grain sizes, which, in turn, reduce the strength of the material under dynamic loading conditions. The volume fraction of the M23C6 "blocky" carbides appears to be independent of the casting conditions; however, their size and spatial distributions determine the strength of the as-cast alloys.

Alloys↗
PubMed1997

Testing topographic differences between event related brain potentials by using non-parametric combinations of permutation tests.

MANOVA and repeated measures ANOVA approaches have provided evidence of a number of limitations in several event-related potential (ERP) studies due to violations of their statistical assumptions and the typically moderate size of the available sample. Alternative, computer-intensive methods based on permutation principles have recently been developed. Up to now this methodology has focused mostly on magnitude differences between scalp distributions as measured by t statistics. In this paper the scope of permutation techniques in ERP analysis was widened. A new statistic (D statistic) is introduced to compare the shapes of scalp distributions of ERPs. Additionally a general non-parametric combinatory technique is introduced to evaluate, by means of multivariate permutation tests, several time points and/or recording sites in ERP data. The methodology described here was used to test if two ERP components elicited during word-pair matching tasks to semantic or phonological incongruences had different scalp distributions.

Adolescent↗
PubMed1997

Association of cilia-associated respiratory (CAR) bacillus with natural chronic tracheitis in goats.

A histological, histochemical and immunohistological study of the respiratory tract of 83 slaughtered goats (50 adults and 33 kids) is described. Cilia-associated respiratory (CAR) bacillus was detected by means of the Warthin Starry method in the tracheal epithelium of seven (21.2%) of the kids and 16 (32%) of the adult goats. A chronic diffuse tracheitis characterized by mixed lymphocyte and plasma-cell infiltration was found in all seven kids and in 17 adults, including the 16 infected with the CAR bacillus. Although not proved, it is possible that the CAR bacillus caused the chronic tracheitis. Immunohistochemical results suggested that the caprine CAR bacillus was closely related to the rabbit CAR bacillus.

Animals↗