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Biomedical subjects

R Vazquez

Publications and source records attributed to R Vazquez.

At least 19 recordsLinked to original sources
PubMed2006

Exploring the association between anorexia nervosa and geographical latitude.

OBJECTIVE: This paper explores the relationship between anorexia nervosa (AN) and climate by mapping the distribution of references of AN in the literature at different latitudes. METHOD: The distributions of the bibliographic references of two medical disorders -psoriasis and cataracts-, and four mental disorders -AN, anxiety disorders, seasonal affective disorders, and schizophrenia- were mapped according to the institutional affiliation of their first author. RESULTS: The distribution of references to AN was quite similar to the mental and medical disorders associated to high latitudes, although references to AN were more frequent in the range of 40 masculine-55 masculine in the Northern Hemisphere. DISCUSSION: The psychosocial and sociocultural features of 'cultures' do not exhaust the factors defining the environment in which we live. Our findings indicate that climatic parameters, such as latitude may be a relevant factor in the occurrence of AN.

Anorexia Nervosa↗
PubMed2005

Clinical efficacy of anti-pneumococcal vaccination in patients with COPD.

BACKGROUND: A study was undertaken to evaluate the clinical efficacy of the 23-valent pneumococcal polysaccharide vaccine (PPV) in immunocompetent patients with chronic obstructive pulmonary disease (COPD). METHODS: A randomised controlled trial was carried out in 596 patients with COPD of mean (SD) age 65.8 (9.7) years, 298 of whom received PPV. The main outcome was radiographically proven community acquired pneumonia (CAP) of pneumococcal or unknown aetiology after a mean period of 979 days (range 20-1454). RESULTS: There were 58 first episodes of CAP caused by pneumococcus or of unknown aetiology, 25 in the intervention group and 33 in the non-intervention group. Kaplan-Meier survival curves for CAP did not show significant differences between the intervention and non-intervention arms (log rank test = 1.15, p = 0.28) in the whole group of patients. The efficacy of PPV in all patients was 24% (95% CI -24 to 54; p = 0.333). In the subgroup aged <65 years the efficacy of PPV was 76% (95% CI 20 to 93; p = 0.013), while in those with severe functional obstruction (forced expiratory volume in 1 second <40%) it was 48% (95% CI -7 to 80; p = 0.076). In younger patients with severe airflow obstruction the efficacy was 91% (95% CI 35 to 99; p = 0.002). There were only five cases of non-bacteraemic pneumococcal CAP, all in the non-intervention group (log rank test = 5.03; p = 0.025). Multivariate analysis gave a hazard ratio for unknown and pneumococcal CAP in the vaccinated group, adjusted for age, of 0.20 (95% CI 0.06 to 0.68; p = 0.01). CONCLUSIONS: PPV is effective in preventing CAP in patients with COPD aged less than 65 years and in those with severe airflow obstruction. No differences were found among the other groups of patients with COPD.

Adult↗
PubMed2004

Unreported sauna use in anorexia nervosa: evidence from the world-wide-web.

Weight loss methods employed in anorexia nervosa (AN) are vomiting, laxatives, diuretics, enemas, suppositories, ipecac, weight loss medications and inadequate insulin in diabetics. Some methods result in weight loss from fluid depletion and not a reduction in body fat. Sauna use causes rapid fluid loss, but has not been reported in the medical literature as a weight loss strategy used in AN. We found reports of sauna use in AN on the world-wide-web are rare. We hypothesize that the warming caused by the use of sauna, may result in physical improvement in AN and thereby reduce its acceptability as a weight loss strategy.

Anorexia Nervosa↗
PubMed2001

Heat in the treatment of patients with anorexia nervosa.

The paper presents the results of heat treatment in three cases of anorexia nervosa (AN), in which marked overactivity and/or strenuous exercising were prominent clinical features. Heat was supplied in three ways: continuous exposure to a warm environment, wearing a thermal waistcoat, and sauna baths in an infrared cabin. The outcomes went far beyond what had been expected, as the disappearance of hyperactivity was followed by progressive recovery.

Adult↗
PubMed1999

Efficacy and pharmacodynamics of teicoplanin given daily during the first 3 days and then on alternate days for methicillin-resistant Staphylococcus aureus infections.

Fifteen evaluable patients (mean age, 67 years) were enrolled to assess the efficacy of teicoplanin, 6 mg/kg given daily during the first 3 days and then on alternate days, for the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections. Eight patients had soft tissue infections, four catheter-associated bacteraemia, two osteomyelitis and one pneumonia. Clinical cure was observed in 13 of 15 patients. Both clinical and bacteriological failures were shown in the two patients with osteomyelitis. The mean serum levels of teicoplanin (mg/L) were 22, 8 and 6.7 for peak, 24 h and 48 h troughs, respectively. The dosage employed in this study proved effective in non-deep-seated MRSA infections.

Adult↗
PubMed1998

Increased risk of autoimmune thyroid disease in hepatitis C vs hepatitis B before, during, and after discontinuing interferon therapy.

BACKGROUND: Thyroid gland dysfunction has been reported to occur with variable frequency during interferon alfa (IFN-alpha) therapy in patients with the hepatitis C virus (HCV). We prospectively evaluated if the prevalence of autoimmune thyroid disease in patients with HCV differs from that in patients with the hepatitis B virus (HBV) before, at the end of, and 6 months after stopping treatment with IFN-alpha. METHODS: One hundred thirty-four patients with HCV and 41 patients with HBV were studied. Measurements of serum free thyroxine, free triiodothyronine, thyrotropin, thyroid peroxidase antibodies (TPOAbs), thyroglobulin antibodies (TgAbs), and thyrotropin-binding inhibitory immunoglobulin were performed. RESULTS: Positive levels of TPOAb and TgAb were found in 20% and 11% of patients with HCV compared with 5% and 3% of patients with HBV, respectively. At the end of IFN-alpha therapy, thyroid gland dysfunction was more prevalent in patients with HCV (12%) compared with those with HBV (3%), with thyrotropin levels significantly higher in the HCV group (P = .03). Titers of TPOAb, TgAb, and thyrotropin-binding inhibitory immunoglobulin increased significantly (P = .02, P = .04, and P = .02, respectively) at the end of IFN-alpha therapy in patients with HCV but not in those with HBV. Patients who developed thyroid gland dysfunction were predominantly female (P = .03), had decreased levels of free triiodothyronine (P<.001), and had a higher prevalence of TPOAb (P = .03) before treatment with IFN-alpha. Thyroid gland dysfunction was reversed in 60% of those with HCV 6 months after discontinuing treatment with IFN-alpha. CONCLUSIONS: Patients with HCV are more susceptible than patients with HBV to autoimmune thyroid disease. Systematic screening of thyroid gland function and TPOAb titers in all patients with HCV before, during, and after IFN-alpha therapy appears warranted. This precaution is not necessary for patients with HBV.

Adolescent↗
PubMed1996

Dopamine inhibits in vitro release of VIP and proliferation of VIP-immunoreactive pituitary cells.

A double immunohistochemical study for VIP and proliferating cell nuclear antigen (PCNA) was carried out on monolayer cultures from adult male rats pituitary glands treated with dopamine (ranging from 10(-9) to 10(-5) M), in order to establish whether or not dopamine is involved in the regulation of the proliferation rate of pituitary VIP-immunoreactive cells. For all doses of dopamine assayed, the release of VIP to the culture medium, the numerical density of VIP-immunoreactive cells and the percentages of VIP- and PCNA-immunoreactive cells decreased significantly after dopamine treatment. These results suggest that dopamine could be a physiological inhibitor involved in the modulation of pituitary VIP proliferation rate.

Animals↗
PubMed1996

Invasin of Yersinia pseudotuberculosis activates human peripheral B cells.

The Yersinia pseudotuberculosis cell surface-located protein invasin was found to promote binding between the pathogen and resting peripheral B cells via beta 1 integrin receptors (CD29). B cells responded by expressing several activation markers and by growing, In contrast, T cells did not react, although these cells express CD29. An isogenic invA mutant failed to activate B cells. The mutation could be complemented by providing the invA+ gene in trans. Purified invasin alone did not activate B cells, although it was able to block the binding of bacteria to the cells.

Adhesins, Bacterial↗
PubMed1996

A three-dimensional virtual model of the head generated from digitalized CT or MR images for anatomical-radiological and neurosurgical evaluations.

A computer-generated virtual model has been developed that reconstructs the head in three dimensions from digitalized images obtained with magnetic resonance and computerized tomography. Through programming and the use of commercial graphic animation software, we have developed the whole process of the rotation of the head on different spatial planes. The procedure permits multidirectional anatomical sections to be made on the structure of the head, providing a true dynamic and user-friendly anatomical-radiological atlas. The system serves as a virtual model for the localization of an ideal surgical approach to any lesion thus avoiding possible neurological lesions.

Anatomy, Artistic↗
PubMed1995

Isolation and enzymic properties of levansucrase secreted by Acetobacter diazotrophicus SRT4, a bacterium associated with sugar cane.

Acetobacter diazotrophicus, a nitrogen-fixing bacterium associated with sugar cane, secretes a levansucrase (sucrose-2,6-beta-D-fructan 6-beta-D-fructosyltransferase; EC 2.4.1.10). This enzyme is constitutively expressed and represents more than 70% of the total proteins secreted by strain SRT4. The purified protein consists of a single 58 kDa polypeptide with an isoelectric point of 5.5. Its activity is optimal at pH 5.0. It catalyses transfructosylation from sucrose to a variety of acceptors including water (sucrose hydrolysis), glucose (exchange reaction), fructan (polymerase reaction) and sucrose (oligofructoside synthesis). In vivo the polymerase activity leads to synthesis of a high-molecular-mass fructan of the levan type. A. diazotrophicus levansucrase catalyses transfructosylation via a Ping Pong mechanism involving the formation of a transient fructosyl-enzyme intermediate. The catalytic mechanism is very similar to that of Bacillus subtilis levansucrase. The kinetic parameters of the two enzymes are of the same order of magnitude. The main difference between the two enzyme specificities is the high yield of oligofructoside, particularly 1-kestotriose and kestotetraose, accumulated by A. diazotrophicus levansucrase during sucrose transformation. We discuss the hypothesis that these catalytic features may serve the different biological functions of each enzyme.

Acetobacter↗
PubMed1995

Experience with a new valvulotome for lower-extremity revascularization procedures by the in situ method.

Between November 1990 and November 1992, 50 consecutive cases requiring lower-extremity revascularization by the in situ method were compared with regard to use of two different valve cutters, the Hall valvulotome and the Insitucat. There were no amputations in patients with patent grafts, nor were any infections or false aneurysms noted during the course of this study. In the Insitucat group (n = 25), primary patency was achieved in 19 cases. Five of the six graft failures underwent additional procedures of which three remained patent, adding to the secondary patency rate (22 of 25). The greatest problem with regard to maintaining primary graft patency was that of missed or retained valves, but the incidence of this problem decreased during the course of this study as experience was gained with the catheter in conjunction with angioscopy. Experience with the Insitucat valvulotome has demonstrated its efficacy, though enhanced by monitoring the results with angioscopy. The development and discovery of focal stenotic areas and retained valves by surveillance sonography have resulted in enhanced (assisted) primary graft patency rates. The incidence of these problems appears to be comparable with that occurring with other means of producing valvular incompetence for an in situ reconstruction where valvulotomes of similar design are employed. This was confirmed by comparative analysis with another group of 25 in situ vein bypasses performed during the same time period but during the Hall valvulotome.

Aged↗
PubMed1995

Morphological findings of an interrelationship among the neurosecretory axons of the neural lobe of the hypophysis.

In order to establish whether osmotic stimuli induce variations in the contact regions among neurosecretory axons of the neural lobe of the hypophysis, adult Sprague-Dawley rats of both sexes were treated with furosemide, a diuretic drug. Contacts between adjacent membranes with no condensations of the axolemma but increase in their osmiophilia were observed. After treatment with furosemide interaxonal contacts were significantly increased (p < 0.01, in relation to control animals). Additionally, following treatment with furosemide, axo-axonic synapses among the axons of the neural lobe were found. These findings suggest the existence of interactions among activated neurosecretory axons of the neural lobe of the adult rat.

Animals↗
PubMed1994

In vitro and in vivo evidence for direct dopaminergic inhibition of VIP-immunoreactive pituitary cells.

In order to establish whether dopamine is involved in the regulation of immunocytochemical expression of VIP in pituitary cells, in vivo and in vitro studies were carried out on male rats after treatment with haloperidol and dopamine, respectively. In the in vivo studies, following intraventricular (third ventricle) administration of haloperidol, an increase in the total number of VIP-immunoreactive cells (p < 0.05) was observed; additionally, the cellular, cytoplasmic and nuclear areas were increased (p < 0.01). The in vitro studies demonstrated that dopamine induces a significant decrease (p < 0.05) in the total number of VIP-immunoreactive cells, which were smaller than the cells from the control dishes, because dopamine induces a significant decrease in their cellular, cytoplasmic and nuclear areas (p < 0.01). These results support the hypothesis that dopamine is a physiological inhibitor of pituitary VIP expression and suggest that dopamine modulates the auto- or paracrine effects of VIP in the rat pituitary.

Animals↗
PubMed1994

Changes in the neurosecretory axons of the neural lobe of the hypophysis of rats treated with met-enkephalin. An ultrastructural study.

Following administration of met-enkephalin into the third ventricle of rats of both sexes, an ultrastructural-morphometric study was carried out of the neural lobe of the hypophysis, comparing the results with those obtained in untreated animals, controls (injected intraventricularly with distilled water) and animals previously receiving naloxone intraperitoneally. In the untreated and control animals, both males and females, there was a high percentage (about 70%) of neurosecretory axons considered to have a normal morphology; after met-enkephalin administration, this percentage decreased and was accompanied by a rise (slightly more pronounced in the females) in the percentage of degranulated axons and a slight rise in axons with a morphology indicative of regenerative and degenerative phases. Previous administration of the opiate antagonist naloxone led to a rise in the number of axons in the degenerative phase with respect to the other groups of animals; this occurred in both sexes.

Animals↗
PubMed1994

Repercussion of craniopharyngioma on the morphology of the rostral wall of the III ventricle. A combined TEM and SEM study.

Using a combined scanning and electron microscope technique, the repercussion on the rostral wall of the III ventricle in a patient affected with a retrochiasmatic craniopharyngioma with growth in the ventricular direction were analysed. The apical surface of the ependymocytes was found to be free of cilia, although there were numerous microvilli. The most striking finding appreciated with the scanning electron microscope was the presence of bulbous protrusions towards the lumen of the ventricle; these were formed of cells with shapes, sizes and surface characteristics different from the rest of the ependyma, which appeared flattened. The ultrastructural study revealed the presence of large numbers of filaments and junction complexes both in the ependymal and subependymal cells. Additionally, the protruded zones corresponded to areas showing different degrees of cellular disorganization.

Cerebral Ventricles↗
PubMed1993

Calretinin immunoreactivity in the magnocellular neurosecretory nuclei of the rat hypothalamus.

The distribution of calretinin-immunoreactivity in the magnocellular neurosecretory nuclei of the rat hypothalamus was studied using a polyclonal antibody and the avidin-biotin immunoperoxidase technique. Calretinin-immunoreactive neurons were observed in the supraoptic and paraventricular nuclei. Additionally, we detected for the first time, immunoreactive neurons located in the circularis and fornicals nuclei, and isolated positive neurons situated in the hypothalamic area located between the supraoptic and paracentricular nuclei. When these results were compared to those obtained in previous studies for another two calcium-binding proteins: calbindin D-28k and parvalbumin, two major differences may be concluded: a) a different distribution of calretinin, especially in the paraventricular nucleus, and b) an expression of calretinin lower than calbindin D-28k and higher than parvalbumin in the magnocellular hypothalamic nuclei. Of special interest is the fact that calretinin is one of the few markers which demonstrates predominantly parvicellular neurons in the paraventricular nucleus. Although the exact biochemical function of these three calcium-binding proteins remains unknown, their uneven and characteristic distributions strongly suggest that specific neuronal populations in the hypothalamus may use alternatively different calcium-sequestering molecules.

Animals↗