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Biomedical subjects

G Hernández

Publications and source records attributed to G Hernández.

At least 19 recordsLinked to original sources
PubMed2006

Different modes of translation for hid, grim and sickle mRNAs in Drosophila.

Protein synthesis is inhibited during apoptosis. However, the translation of many mRNAs still proceeds driven by internal ribosome entry sites (IRESs). Here we show that the 5'UTR of hid and grim mRNAs promote translation of uncapped-mRNA reporters in cell-free embryonic extracts and that hid and grim mRNA 5'UTRs drive IRES-mediated translation. The translation of capped-reporters proceeds in the presence of cap competitor and in extracts where cap-dependent translation is impaired. We show that the endogenous hid and grim mRNAs are present in polysomes of heat-shocked embryos, indicating that cap recognition is not required for translation. In contrast, sickle mRNA is translated in a cap-dependent manner in all these assays. Our results show that IRES-dependent initiation may play a role in the translation of Drosophila proapoptotic genes and suggest a variety of regulatory pathways.

5' Untranslated Regions↗
PubMed2005

Cannabinoids and dopamine receptors' action on calcium current in rat neurons.

OBJECTIVE: To study the effects of cannabinoid, glutamate, and dopamine agonists and antagonists on the calcium current rat sympathetic neurons. METHODS: Calcium current was recorded using the whole-cell variant of the patch-clamp technique. After expression in neuronal membranes of the cannabinoid CB1, glutamate mGluR2, or dopamine D1 receptor (by microinjection of the levant receptor's cDNA into the neuron's nucleus) agonists' and antagonists' effects were observed. RESULTS: Applications of agonists of the expressed receptor (0.1-10 microM) decreased the calcium current. The calcium current was increased after application of cannabinoid antagonists (AM251 and AM630); these compounds thus act as inverse agonists in this preparation. Glutamate and dopamine antagonists had no effects on the calcium current by themselves. Combined application of cannabinoids and dopamine, but not glutamate, agonists produced a decrement in the calcium current that was bigger than either of the effects seen when one agonist was applied alone. CONCLUSIONS: These results suggest that cannabinoid with dopamine receptors have an interactive inhibitory effect on the calcium current in this preparation, indicating that within the nervous system, receptor interactions may be important in the regulation of ion-channel functions.

Animals↗
PubMed2005

Study of intrinsic flow properties at the normal pregnancy second trimester.

During normal pregnancy the cardiovascular system undergoes extensive changes. In a previous work we demonstrated the role of the haemorheological profile as predictor of hypertensive gestational disorders through a retrospective study. In an attempt to clarify the rheological characteristics during normal gestation, blood and plasma viscosity, erythrocyte deformability and aggregation, and plasma fibrinogen levels were measured at second trimester of pregnancy. The interrelationships of different haemorheologic parameters, were analysed by Pearson correlation coefficient. The results showed decreased erythrocyte deformability, and increased plasma viscosity and erythrocyte aggregation due to increased fibrinogen in pregnant women. Despite these modifications blood viscosity did not increase, but there was a decrease in relative blood viscosity, therefore, a profile in accordance, from the haemorheological point of view, with the classical concept stating that haemodilution is of the utmost importance to maintain an adequate microcirculation in the uteroplacental unit during normal gestation.

Adolescent↗
PubMed2005

[Diagnostic value and test-retest reliability of the Blessed Dementia Rating Scale for Alzheimer's disease: data from the NORMACODEM project].

INTRODUCTION: This study aims to discover the criterion validity of the Blessed Dementia Rating Scale (BDRS) for the diagnosis of Alzheimer's disease. Different cut-off scores and corresponding diagnostic sensitivities and specificities were established. Test-retest reliability and internal consistency of the BDRS were also analyzed. METHODS SAMPLE: 451 subjects were studied (254 controls, 86 subjects with mild cognitive impairment and 111 patients with Alzheimer's disease). INSTRUMENTS: scores from different sections of the Blessed score were obtained. The global score (BBRS-Total) is the result of the sum of the three sections, A (changes in every day activities), B (changes in habits) and C (changes in personality). The sum of parts A and B (BDRS-Mod) were also quantified. STATISTICS: ROC curves, intraclass correlation coefficient and Cronbach's alpha. RESULTS: The best cut-off score for the BDRS-Total was 3.5 (sensitivity: 87.39%, and specificity: 90%). For the BDRS-Mod, the best cut-off score was 1.5 (sensitivity: 90%, and specificity: 89%). Area under the ROC curve was 0.964 and 0.963 respectively. Intraclass correlation coefficient was 0.98 and Cronbach's alpha was 0.925. CONCLUSIONS: The BDRS has good discriminative validity in terms of sensitivity, specificity and predictive value. It also has good test-retest reliability and internal consistency.

Adult↗
PubMed2004

Percutaneous tracheostomy: Ciaglia Blue Rhino versus Griggs' Guide Wire Dilating Forceps. A prospective randomized trial.

BACKGROUND: Percutaneous tracheostomy (PT) has gained widespread acceptance to control the airway in patients requiring prolonged mechanical ventilation. Since 1985, new techniques for PT have been described. It was the aim of this investigation to compare two different PT techniques: the Ciaglia Blue Rhino (CBR) and the Guide Wire Dilating Forceps (GWDF). METHODS: A prospective randomized trial was performed in four intensive care units. After informed consent, 53 consecutive patients were randomized to undergo CBR or GWDF. Procedural complications were evaluated and specific symptoms of the upper airway tract in survivors were assessed. RESULTS: Twenty-seven patients were randomly assigned to CBR and 26 to GWDF. Patients mean ages were 62.7 +/- 15.8 years and 62.2 +/- 18.3, respectively. Mean APACHE II scores were 20.6 +/- 6.8 and 21.2 +/- 7.2, respectively. Median duration of the procedure was 7 min (range: 4-17 min) with GWDF and 9 min (range: 5-32 min) with CBR (P = 0.16). Seven patients in the group undergoing GWDF had complications (desaturation: two; mild bleeding: one; infected stoma: one; inability to complete the procedure: three). Two patients had complications in the group undergoing CBR (mild bleeding) (P = 0.07). Survivors were followed up after discharge. Three patients (all of them having undergone GWDF) were symptomatic (two with mild hoarseness and one with a persistent foreign body sensation), but laryngotracheoscopy was negative. CONCLUSIONS: Our results show no differences between both techniques regarding surgical duration or procedural complications. Late symptoms were encountered in three patients undergoing GWDF, however, laryngotracheoscopy failed to document anatomical or functional abnormalities.

Chi-Square Distribution↗
PubMed2004

Developmental expression of neurotensin in thyrotropes and gonadotropes of male and female rats.

Besides its potential roles as a central neuromodulator or a hypothalamic neurohormone, neurotensin (NT) may also have endocrine function in the anterior pituitary of mammals. We previously found that NT immunoreactivity is present in the secretory granules of gonadotropes and thyrotropes in both male and female rats, where its levels of expression are under the control of sex steroids. In this work, using immunocytochemistry and in situ hybridization, we have studied the postnatal development of NT-like immunoreactivity (NTir) and the mRNA encoding NT (mRNA-NT) in specific anterior pituitary cells of both male and female rats. NT expression starts after birth and displays an identical pattern in both sexes until sexual maturity, with mRNA-NT being detected from day 2 of postnatal life in thyrotropes localized in the central portion of the anterior lobe. This pattern of expression develops progressively throughout the 2nd and 3rd weeks in both sexes. By the beginning of the 3rd week, mRNA-NT can also be detected in gonadotropes localized in the periphery of the gland coinciding with a rise in serum estradiol concentrations in both sexes, and by day 21, mRNA-NT is extensively present in both the periphery and the central region. NTir is observed from days 5-6 in thyrotropes predominantly localized in the central portion of the anterior lobe, and by day 21, NTir is also detected in gonadotropes localized in the periphery of the gland. This pattern remains similar in both sexes until the time of puberty, when female rats start displaying plastic changes in NT expression according to the stage of the estrous cycle. These findings indicate that NT expression in the rat anterior pituitary is cell specific, and develops from birth to adulthood under the control of sex steroid hormones. In addition, preliminary data showing the presence of NT receptors in rat pituitary cells support the hypothesis of a paracrine or an autocrine role for this peptide within the pituitary.

Aging↗
PubMed2003

Molecular identification of pathogenic and nonpathogenic strains of Vibrio harveyi using PCR and RAPD.

Fifteen environmental samples of Vibrio spp. isolated from healthy and diseased shrimps were tested for pathogenicity to juvenile shrimps. Two isolates, strains Z2 and Z3, were observed to be pathogenic, causing 100% mortality of the target host compared to the control strain Vibrio harveyi ATCC 14126. Environmental and type strains were subjected to molecular characterization by restriction fragment length polymorphism (RFLP) and PCR using primers targeted to different virulence, transcriptional regulator, or quorum sensing genes from V. harveyi. Primers designed for luxN were specific and identified all the environmental strains as V. harveyi. The random amplified polymorphic DNA (RAPD) method was used to differentiate between pathogenic and nonpathogenic strains of V. harveyi. These methodologies allowed us to detect and distinguish strains virulent and avirulent to juvenile shrimp.

Animal Diseases↗
PubMed2003

Weight gain in patients with schizophrenia treated with risperidone, olanzapine, quetiapine or haloperidol: results of the EIRE study.

OBJECTIVES: The aim of this cross-sectional study, the EIRE study, was to assess the frequency of several side effects with antipsychotics in the clinical setting. This paper addresses the adverse effect of weight gain. METHOD: Outpatients diagnosed of schizophrenia according to DSM-IV criteria and receiving a single antipsychotic (risperidone, olanzapine, quetiapine or haloperidol) for at least 4 weeks were consecutively recruited. Data were collected in a single visit, including data on demographic, clinical and treatment characteristics. Mean weight change was evaluated retrospectively by means of clinical charts and the weight at the time of the visit; in addition, the corresponding item of a modified version of the UKU, a Scandinavian side-effect rating scale, was used. Chi-squared test and logistic regression methods were used to analyze frequency of weight gain between treatments. RESULTS: Out of 669 recruited, 636 evaluable patients were assessed. The treatment with the highest number of patients with weight gain as an adverse reaction on the UKU scale was olanzapine (74.5%), followed by risperidone (53.4%) and haloperidol (40.0%). The proportion of patients with clinically relevant weight gain (>or=7% increase versus initial weight) was also higher with olanzapine (45.7%) than with risperidone (30.6%) and haloperidol (22.4%). Five patients (13.5%) treated with quetiapine had some degree of weight gain according to the UKU scale, although no patient showed a clinically relevant weight gain (>or=7%). Treatment with olanzapine and risperidone were identified as risk factors of weight gain versus haloperidol. The risk of weight gain was higher in women (OR: 4.4), overweight patients (OR: 3.0) and in patients with <or=1 year of treatment (OR: 6.3) in the olanzapine group. A higher risk of weight gain in women (OR: 2.6) was also seen with risperidone. CONCLUSION: Clinically relevant weight gain is clearly associated with olanzapine, and to lesser extent, with haloperidol and risperidone. Data for quetiapine were not conclusive because of the short duration of treatment.

Adult↗
PubMed2003

Bone mass and bone modelling markers in hypertensive postmenopausal women.

Numerous phosphocalcium alterations associated with bone mineral density in hypertension have been described, but very few studies assess them. This study assesses bone mass in hypertensive postmenopausal women and the hypertension influence determining both calcium homeostasis and bone turnover markers. Blood and urine samples were analysed for calcium metabolism-related parameters. Densitometry studies were conducted in the lumbar spine (L2-L4). Hypertensive osteoporotic women--selected from 82 women, with 22% osteoporosis prevalence, similar to the rate for the same age in the Spanish population--had significantly higher levels of body mass index (29+/-4 vs 26+/-4, P=0.019), calciuria (293+/-146 vs 210+/-116 mg/24 h, P=0.023) and calcium/creatinine ratio (0.33+/-0.2 vs 0.22+/-0.1 P=0.003) vs hypertensive nonosteoporotic women. No relation was found between systolic and diastolic blood pressure with bone mass. However, there was a negative osteocalcin correlation (r=-0.386, P=0.0001, and r=-0.242, P=0.033). Calciuria is associated with bone mass decrease in hypertensive women, and there is no relation between bone mass and blood pressure.

Adult↗
PubMed2003

Effects of atorvastatin on glucose homeostasis, postprandial triglyceride response and C-reactive protein in subjects with impaired fasting glucose.

AIMS: To investigate the effects of atorvastatin on glucose homeostasis, the basal and postprandial lipid profiles and the CRP levels (C reactive protein) in subjects with impaired fasting glucose (IFG). METHODS: Thirty-three subjects (22 men and 11 women) were included in our study. All displayed an IFG (fasting plasma glucose between 6.1 and 7.0 mmol/l) on at least two occasions during the last 6 months prior the study. They were randomly assigned to receive either 40 mg atorvastatin/day (n=16) or placebo (n=17) over 16 weeks, in a double-blind design. Before and after the end of the study all participants underwent on three consecutive days: a 75-g oral glucose tolerance test, a frequent sampling intravenous glucose tolerance test with Minimal Model analysis and a meal tolerance test (glucose, insulin and triglycerides). CRP was measured before and after the treatment period. RESULTS: CRP decreased significantly in the atorvastatin-treated group compared with the placebo group (percent change respect initial values; -42.3 %[-21.5 to - 63.1] and -9.6%[15.0 to -34.0], respectively, p<0.01). Atorvastatin treatment did not produce any change in oral glucose tolerance categories or induce any change in glucose and insulin response in OGTT. The statin produced a trend towards a significant improvement in insulin sensitivity as expressed by a change in Si from baseline to the end of treatment. Atorvastatin reduced the postprandial response of triglycerides to the meal test compared with placebo (19-26 % across the meal test, p<0.05) correlating with the amelioration observed in Si (-0.34, p<0.05; percentage changes). CONCLUSION: Our results suggest that the use of statins in subjects with IFG seems to include other potentially beneficial actions in addition to their cholesterol-lowering effects.

Adult↗
PubMed2003

Effect of treatment with the selective oestrogen receptor modulator LY117018-HCl on pituitary sensitivity to GnRH and subsequent ovulation.

The effects of LY117018-HCl (LY; a benzothiophene similar to raloxifene) were examined on various reproductive parameters in female rats. Four-day cyclic rats were treated (10:00 h on dioestrus) with LY (0.01, 0.1, 0.5, 1, 2, 4 or 16 mg kg(-1) p.o.) and assessed for ovulation at oestrus. LY inhibited ovulation at doses as low as 0.5 mg kg(-1), and ovulation did not occur at doses of 4 and 16 mg kg(-1). LY (16 mg kg(-1)) reduced wet uterine mass and LH concentrations at the time of the expected ovulatory surge. Ovulation induced by hCG in pentobarbital-treated rats was not altered by LY treatment, indicating normal ovarian sensitivity to gonadotrophins. LY, however, completely blocked the effects of oestradiol (under either negative or positive feedback modes) on LH secretion in ovariectomized rats. GnRH secretion into hypophyseal portal blood during pro-oestrus was not affected by treatment with LY, whereas the concentrations of serum LH remained reduced. Finally, treatment with LY markedly reduced pituitary sensitivity to GnRH during pro-oestrus, as it completely blocked GnRH-induced LH secretion. These results demonstrate that LY inhibits oestradiol action in the uterus and prevents ovulation in normal cyclic rats. LY-induced inhibition of ovulation is not caused by an alteration of the ovarian response to gonadotrophins or an impairment of GnRH secretion at the hypothalamus, but by a reduction in the sensitivity of gonadotrophs to the stimulatory effects of GnRH during pro-oestrus.

Animals↗
PubMed2003

Proposal of a haemorheological profile for early detection of hypertensive gestational disorders.

The objective of this study was to emphasise the potential power of simple and inexpensive haemorheological tests as predictors of hypertensive gestational disorders through a retrospective study. Blood samples of 195 primigravids with gestational age 18-23 weeks were studied. For data processing pregnant women were allocated into 3 groups, based on difference of SBP and DBP values measured at first and last consultation, and presence of proteinuria and oedema: Normotensive pregnants (n=149), hypertensive pregnants; n=26 and preeclamptic pregnants; n=20. Whole blood viscosity, plasma viscosity, erythrocyte rigidity and aggregability, haemoglobin, hematocrit, total protein, albumin and fibrinogen were assayed. Increased relative viscosity (eta(r)) (p<0.01), decreased erythrocyte deformability (p<0.05), lower O(2) release (p<0.01) and birth weight (p<0.01), showed a negative correlation with filterability index in preeclamptics. There was a decrease of erythrocyte deformability in hypertensive women. Erythrocyte deformability and blood viscosity could be an early indicator in preeclamptics, and erythrocyte deformability in hypertensive ones, therefore they could be considered alert factors in order to decide a thorough control in these patients to prevent further complications.

Birth Weight↗
PubMed2003

[A case of malformation in Pachycheles serratus (Decapoda: Porcellanidae)].

An adult male of Pachycheles serratus with a malformation on the right cheliped was found during a collection of anomuran crabs in coastal waters of the peninsula de Macanao, Margarita island, Venezuela. The specimen was found at La Carmela beach (11 degrees 04'N-64 degrees 20'W), and featured a bifurcated fixed finger on the right cheliped.

Animals↗
PubMed2002

Effects of copper on hatching of larvae and prezoea survival of Petrolisthes galathinus (Porcellanidae): assays with ovigerous females and isolated eggs.

Ovigerous females of the porcellanid crab Petrolisthes galathinus were selected for toxicological bioassays. A first assay was made on isolated eggs, exposing them to 0 (control), 0.5, or 1 mgL(-1) copper. Both copper concentrations caused significant mortality just before hatching. The few prezoeas hatched at 0.5 and 1 mgL(-1) were unable to reach the zoea stage. A second assay was conducted on the ovigerous females isolated and exposed to 0 or 0.1 mgL(-1) copper. Females were checked daily and the percentages of mortality, egg loss, and hatching larvae were recorded. No differences in either mortality of females or number of hatched larvae were noted between control and copper-exposed groups. From each of these groups, 15 recently hatched prezoeas were transferred to clean seawater, while another 15 were exposed to 0.1 mgL(-1) copper. The numbers of dead or alive prezoeas, transitional larvae, and zoeas were ascertained every 24 h. Prezoeas hatched from exposed eggs and transferred to clean seawater at hatching showed enhanced mortality and a delay in development, compared with control larvae maintained in clean water throughout. Copper at 0.1 mgL(-1) was lethal to almost all larvae exposed only after hatching, while those that had also been preexposed to copper during embryonic development showed a certain degree of tolerance to copper exposure, at least during the first 24 h after hatching.

Animals↗
PubMed2002

Allelic polymorphism -491A/T in apo E gene modulates the lipid-lowering response in combined hyperlipidemia treatment.

BACKGROUND: Combined hyperlipidemia (CHL) is one of the dyslipidemias more frequently found in clinical practice, and lipid-lowering drugs are often necessary in its management. Some genetic loci have been associated with CHL expression, and some studies have shown modulation of drugs efficiency in the treatment of dyslipidemias by genetic polymorphisms. We have investigated whether common polymorphisms and mutations in the apolipoprotein (apo) E, lipoprotein lipase (LPL), and apo CIII genes influence atorvastatin or bezafibrate responses in patients with CHL. DESIGN: One hundred and sixteen subjects participating in the ATOMIX study (Atorvastatin in Mixed dyslipidemia) were randomized to treatment with either atorvastatin or bezafibrate. Apolipoprotein E genotype and common -491A/T and -219T/G polymorphisms in the apo E gene promoter region, Sst I polymorphism in the apo CIII gene (3238C/G), and D9N and N291S common mutations in the LPL gene were determined by polymerase chain reaction (PCR) and restriction enzyme digestion. RESULTS: Statistical analysis showed the influence of the -491A/T polymorphism in atorvastatin and bezafibrate treatments. Subjects carrying the -491T allele showed an increased LDL-cholesterol-lowering effect with atorvastatin compared with -491T allele noncarriers (-35% vs. -27%, P = 0.037). Subjects carrying the -491T allele, when on bezafibrate treatment, showed a lower triglyceride reduction compared with -491T allele noncarriers (-23% vs. -39%, P = 0.05). CONCLUSIONS: In our study, the -491A/T polymorphism in the apo E gene promoter region modulated the lipid-lowering efficiency of atorvastatin and bezafibrate in CHL patients. Such influence might explain some of the interindividual response variabilities observed for the two drugs, and could help in CHL management.

Adult↗
PubMed2002

Adaptation and standardization of the geriatric evaluation of relative's rating instrument (GERRI) for Spain.

BACKGROUND: The Geriatric Evaluation of Relative's Rating Instrument (GERRI) is a scale that evaluates the frequencies of alterations in behavior and functional capacity over a two-week period prior to exploration. The scale depends on the observations done by a relative o first caregiver of the studied subject. AIM: To adapt and standardize the GERRI for the use in the Spanish population as a part of a general project to standardized cognitive and functional tests. METHOD: The scale was administered to 444 subjects: 249 controls, 85 mild memory-cognitive disorders without dementia subjects (DWD) and 110 patients with Alzheimer-type dementia (ATD). An across-sectional statistical study was conducted in our samples stratified by age, gender and education. We evaluated the reliability of repeatability of the test, the internal reliability and the age, sex and education effects on the score of the different subscales. We also took into account the diagnostical validity in the Alzheimer disease and finally we correlated this test results with Mini mental test. RESULTS: The demographic variables age and schooling were found to affect the GERRI subscales differently. Gender did not reach significance. Internal consistency for the GERRI-Social, -Mood and -Cognitive were 0.8620, 0.7647 and 0.9259, respectively. CONCLUSION: The Spanish version of the GERRI may be applied to Spanish clinical series because of its reliable internal consistency and reproducibility.

Adult↗
PubMed2002

Bioavailability of ranitidine in healthy Mexican volunteers: effect of food.

Is well known that food can affect the bioavailability of several drugs, its impact is major for those drugs that have to act near of drug absorption. Documentation about alterations of ranitidine bioavailability by effect of food is poor. The purpose of this work was to evaluate the effect of food over the bioavailability of ranitidine. Twenty healthy Mexican volunteers were included for the study. The study was made in two stages, in the first one the volunteers had 12 hour fast and took a 300 mg of oral dose of ranitidine (without food, WOF) and blood samples were drawn. Two weeks later, the volunteers took a normal diet just before ranitidine intake (with food, WF). The area under the curve (AUC) was 30% greater in WOF, Cmax was 921.5 ng/ml (WF) vs. 1685.2 (WOF), and t1/2 was 2.70 +/- 1.38 (WF) h vs 3.66 +/- 1.34 (WOF). The AUC, Cmax and t1/2 were statistically different. It is evident that there are differences in the drug disposition due to the presence of food, then, it is possible that the efficacy of ranitidine as inhibitor of gastric secretion being limited by food.

Adolescent↗