Biomedical subjects

M Muñoz

Publications and source records attributed to M Muñoz.

At least 55 records · Page 3Linked to original sources

PubMed2002

Production of antibodies against glycolipids from the Mycobacterium tuberculosis cell wall in aerosol murine models of tuberculosis.

Evolution of antibodies against glycolipids from the Mycobacterium tuberculosis cell wall has been studied for the first time in experimental murine models of tuberculosis induced by aerosol, in which infection, reinfection, reactivation, prophylaxis and treatment with antibiotics have been assayed. Results show a significant humoral response against these antigens, where diacyltrehaloses (DAT) and sulpholipid I (SL-I) elicited higher antibody levels than protein antigens like antigen 85 protein complex (Ag85), culture filtrate proteins (CFP) and purified protein derivative (PPD). Only immunoglobulin M (IgM) antibodies have been detected against DAT and SL-I. Their evolution has a positive correlation with bacillary concentration in tissues.

Acyltransferases↗

PubMed2002

Relation of Apo E and ACE genes to cognitive performance in chronic alcoholic patients.

Apolipoprotein E epsilon4 and ACE genes have been related to several conditions involving cognitive impairment, including Alzheimer's disease, normal ageing and cerebrovascular disease. However, it has not been established whether their genotypes are associated with alcoholism or its cognitive functioning. Genotypic distributions of 140 chronic alcoholic patients were compared with a non-alcoholic sample, and the cognitive performance of a subsample of the alcoholic subjects was assessed with standard neuropsychological tests. No differences in allele or genotype distributions of Apo E or ACE genes were found when comparing controls and alcoholics (Apo E epsilon2/2; patients 1.4%, controls 0% p < 0.06; epsilon2/epsilon3; patients 9.3%, controls 6.6% p < 0.29; epsilon2/epsilon4; patients 0%, controls 1% p < 0.31; epsilon3/epsilon3 patients 71.4%, controls 72% p < 0.89; epsilon3/epsilon4; patients 15.7%, controls 19.2%, p < 0.36; epsilon4/epsilon4; patients 2.1%, controls 1.2% p < 0.44; ACE D/D; patients 35%, controls 28.5% p < 0.14; I/D; patients 47.5%, controls 51.1% p < 0.51; I/I; patients 14.5%, controls 20.4% p < 0.19). In terms of cognitive performance, epsilon4/epsilon3 patients did better on visuoconstructive (p < 0.001) and visual memory (p < 0.04) functions compared with epsilon2/epsilon3 bearers. Furthermore, ACE D/D patients performed better on a test of abstract reasoning (p < 0.03) compared with the ACE I/I homozygous group. The cognitive results suggest that Apo E or ACE genotypes may modify the effects of ethanol on cognitive deterioration in alcoholic patients. However, the data do not support an association between the Apo E epsilon4 allele and reduced cognitive performance in alcoholism.

Adult↗

PubMed2002

Quantified 99mTc-MIBI scintigraphy for predicting chemotherapy response in breast cancer patients: factors that influence the level of 99m Tc-MIBI uptake.

The aim of this study was to establish whether tumour uptake of 99mTc-MIBI can predict response to chemotherapy in patients with breast carcinoma. Forty women suffering from breast carcinoma confirmed by tumour biopsy were studied prospectively. Fifteen patients subsequently underwent surgery and 25 were candidates for neoadjuvant chemotherapy. Breast scintigraphy was performed and planar and tomographic views (single photon emission computed tomography (SPECT)) were obtained after injection of 740 MBq of 99mTc-MIBI. The tumoural uptake was quantified by computer analysis. P-glycoprotein was evaluated by immunohistochemistry only in operable patients. The response to chemotherapy was evaluated at 3 months upon completion of treatment. The results of this study showed no relationship between 99mTc-MIBI uptake and the histological type or tumour size. There was an inverse correlation with the degree of tumour differentiation (P<0.05). 99mTc-MIBI uptake in negative P-glycoprotein lesions (2.36+/-1.72) was higher than in positive P-glycoprotein lesions (1.53+/-1.29), although the difference was not statistically significant. Lesions which responded to chemotherapy (16) showed higher 99mTc-MIBI uptake (7.70+/-5.20) than non-responding lesions (nine) (2.21+/-1.0) (P<0.001). In conclusion, there is a correlation between 99mTc-MIBI uptake in breast cancer and response to chemotherapy. Furthermore, 99mTc-MIBI uptake may be influenced by other factors such as the degree of tumour differentiation or tumour P-glycoprotein levels.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2001

Comparative analysis of adrenomedullin-like immunoreactivity in the hypothalamus of amphibians.

Adrenomedullin (AM) is a novel neuropeptide with special significance in the mammalian hypothalamo-hypophysial axis. By using an antiserum specific for human AM, we have studied the localization of AM-like immunoreactive (AMi) cell bodies and fibers in the hypothalamus and hypophysis of the amphibians Rana perezi (anuran), Pleurodeles waltl (urodele), and Dermophis mexicanus (gymnophionan). Distinct AMi cell groups were found for each species. In the anuran, six cell groups were localized in the preoptic and infundibular regions, whereas only three and one were found in the urodele and gymnophionan, respectively. A comparative analysis of AMi cells and cells expressing arginine vasotocin (AVT), neuropeptide Y (NPY), and tyrosine hydroxylase (TH) revealed strong differences between species. Thus, colocalization of AVT/AM is most likely to occur in the preoptic magnocellular nucleus of urodeles and it is reflected by the intense AM immunoreactivity in the neural lobe of the hypophysis. Colocalization of NPY/AM seems to be possible in the suprachiasmatic nucleus of anurans. In the gymnophionan, cells containing AVT and NPY are distinct from AMi cells. Only in anurans, the ventral aspect of the suprachiasmatic nucleus possesses a small population of AMi cells that express also TH immunoreactivity and most likely also express NPY. The results strongly suggest that AM in amphibians plays an important regulatory role in the hypothalamo-hypophysial system, as has been demonstrated in mammals. On the other hand, substantial differences have been found between species with respect to the degree of colocalization with other chemical substances.

Adrenomedullin↗

PubMed2001

[Association of thyroid hemiagenesis and Graves disease].

Thyroid hemiagenesis is a very infrequent abnormality. We present a case of Graves disease associated to a congenital hemiagenesis of the thyroid gland. The thyroid scintigraphy, ultrasonography and laboratory analysis (that showed the existence of thyroid hyperfunction and the present of thyroid stimulating antibodies) were decisive in the diagnosis.

Atrophy↗

PubMed2001

Primary leptomeningeal melanoma in a child.

Primary malignant melanoma of the leptomeninges is a rare and aggressive tumor in children and accounts for less than 1% of all pediatric malignancies. Usually its symptoms include raised intracraneal pressure resulting from hydrocephalus secondary to tumoral obliteration of basal cisterns, but the passage of time from the initial symptomatology to diagnosis is frequently delayed. A 7-year-old male with primary leptomeningeal melanoma is reported. At the beginning, he presented ataxia and dysarthria followed by symptoms of raised intracranial pressure, complex partial seizures, progressive loss of consciousness, and coma. Cerebrospinal fluid analysis demonstrated raised opening pressure, normal glucose, and increased protein concentration, but malignant melanoma cells were not found. Magnetic resonance imaging scans depicted bright signals in the subarachnoid spaces on T(1) images and gadolinium-enhanced focal lesions. Cerebral biopsy was proposed, but it was not authorized. Definitive diagnosis was thus made by pathologic postmortem examination.

Brain↗

PubMed2001

Distribution of adrenomedullin-like immunoreactivity in the central nervous system of the frog.

Adrenomedullin (AM) is a recently discovered peptide widely distributed in the mammalian brain. By using an antiserum specific for human AM, we have analyzed the localization of AM-like immunoreactivity in the brain and spinal cord of the anuran amphibian Rana perezi. Cell bodies immunoreactive (AMi) for AM were located in the dorsal, lateral and medial pallial regions, diagonal band of Broca, medial septum, and above and rostral to the anterior commissure. A large population of AMi neurons was located in the anterior preoptic area, suprachiasmatic nucleus and in the infundibular hypothalamus. The processes of these latter cells are part of the hypothalamo-hypophysial pathway to the neural and intermediate lobes. Labeled cells were observed in the pretectal region, posterior tubercle and the mesencephalic anteroventral tegmental nucleus. Strikingly, Purkinje cells in the cerebellum also showed AM immunoreactivity, albeit not all of these cells were equally stained. Additional cells were located in the parabrachial region, principal trigeminal sensory nucleus, reticular nuclei medius and inferior, and the intermediolateral gray of the spinal cord. Immunolabeled fibers were widespread throughout the brain and spinal cord of the frog. They were particularly abundant in the medial amygdala, hypothalamus, mesencephalic tectum, periventricular gray and spinal cord. The distribution pattern of AM-like immunoreactivity in the brain of the frog is very selective and does not correspond with the pattern observed for any other transmitter or neuroactive molecule. The wide distribution of this peptide strongly suggests that it may play a significant role in the multiple neuronal functions in the amphibian brain.

Adrenomedullin↗

PubMed2001

Self-aware sex education: a theoretical and practical approach in Venezuela.

Even a few decades ago, it was considered normal and even desirable in Latin America for young women to become pregnant before they were 20--provided they were married; while young men were expected to become sexually active as soon as they entered adolescence, without much concern about potential risks or with whom they did so--as long as it was a woman. This view is now changing. There seems to be a general consensus that 'education' is necessary to prevent adolescent pregnancy, abortion, STI/HIV and sexual abuse. Attempts to reach agreement as to what kind of education and where, and how and when to provide it often fail, however, because of the conflicting views of sexuality upon which they are based. This article discusses conflicting concepts of sexuality and describes the theory of critical pedagogy followed by AVESA, a Venezuelan NGO whose work focuses on sexuality, problems of sexuality and alternative sex education. It describes AVESA's practical experience in training youth promoters and running on ongoing youth education programme in sexual and reproductive health. AVESA advocates an educational alternative that builds self-awareness and a critical understanding of social reality. We encourage individuals to engage with their own history and circumstances in order to be able to experience their sexuality in a full, responsible, pleasurable and just manner.

Adolescent↗

PubMed2001

Phylogenetic placement of a novel tenuivirus from the grass Urochloa plantaginea.

Evidence is presented that a tenuivirus recovered from the grass Urochloa plantaginea is probably a novel tenuivirus species, to be called Urochloa hoja blanca virus (UHBV). It is related to both Echinochloa hoja blanca virus (EHBV) and Rice hoja blanca virus (RHBV), and these three form a group distinct from Maize stripe virus (MStV) and Rice stripe virus (RStV). Phylogenetic analysis of the sequence data for RNA-3 and RNA-4 of these viruses supports the hypothesis that EHBV and UHBV may have evolved from an ancestral form of RHBV, precipitated by the introduction of Echinochloa colona and Urochloa plantaginea to America.

Phylogeny↗

PubMed2001

Cortical projections of the non-entorhinal hippocampal formation in the cynomolgus monkey (Macaca fascicularis).

Episodic memory consolidation requires the integrity of the anatomical pathways between the cerebral cortex and the hippocampal formation. Whilst the largest cortical output of the hippocampal formation originates in the entorhinal cortex, direct projections from CA1, subiculum and presubiculum to the cortex have been reported. The aim of this study is the assessment of the extent, topography and relative strength of those projections, as a parallel/alternate route of memory processing. A total of 45 injections in 28 Macaca fascicularis monkeys were used. Cortical deposits of fluorescent tracers (20 cases, 3% Fast Blue, 2% Diamidino Yellow) or 1% WGA-HRP (eight cases) were made in different cortical areas of the frontal, temporal and parietal lobes, as well as cingulate cortex by direct exposure of the cortical surface. After appropriate survival, animals were perfused and the brains serially sectioned at 50 microm and the retrograde labelling charted with an X-Y digitizing system. Retrograde neuronal labelling was observed in CA1, subiculum, presubiculum and parasubiculum; it was absent in the dentate gyrus, CA3 and CA2. Compared to other portions of the hippocampal formation, the CA1-subiculum border had the highest number of labelled neurons (especially after deposits in the rostral perirhinal cortex), followed by medial frontal cortex, temporal pole, orbitofrontal, anterior and posterior cingulate cortices, parietal and inferotemporal cortices, and no labelling after posterior inferotemporal and lateral frontal cortices. Our results indicate that CA1, subiculum, presubiculum and parasubiculum send direct output to cortical areas. This nonentorhinal, hippocampal formation cortical output may be relevant in memory processing.

Animals↗

PubMed2001

Evaluation of Activated Sludge Model No. 2 at high phosphorus concentrations.

This paper presents laboratory scale experimentation carried out to study enhanced biological phosphorus removal at high phosphorus concentrations in a sequencing batch reactor. Four series of data obtained in a sequencing batch reactor are examined in light of the Activated Sludge Model No. 2. This model was calibrated using data from the first and second series working at low phosphorus concentrations. The Activated Sludge Model No. 2 successfully characterised the enhanced biological phosphorus removal performance of the sequencing batch reactor at low phosphorus concentrations. The calibrated model was then used to adjust experimental results of the other series working at high phosphorus concentration. Differences between model predictions and experimental data could be explained by redissolution in the anaerobic phase and precipitation in the aerobic phase of calcium phosphates not taken into account by the model. This hypothesis can be justified by the conditions of pH and phosphorus concentration prevailing in the experiments and it was confirmed by the results of another experiment in which precipitated phosphorus profile was measured during the cycle.

Bioreactors↗

PubMed2001

Resistance to nucleoside analog reverse transcriptase inhibitors mediated by human immunodeficiency virus type 1 p6 protein.

Resistance of human immunodeficiency virus type 1 (HIV-1) to antiretroviral agents results from target gene mutation within the pol gene, which encodes the viral protease, reverse transcriptase (RT), and integrase. We speculated that mutations in genes other that the drug target could lead to drug resistance. For this purpose, the p1-p6(gag)-p6(pol) region of HIV-1, placed immediately upstream of pol, was analyzed. This region has the potential to alter Pol through frameshift regulation (p1), through improved packaging of viral enzymes (p6(Gag)), or by changes in activation of the viral protease (p6(Pol)). Duplication of the proline-rich p6(Gag) PTAP motif, necessary for late viral cycle activities, was identified in plasma virus from 47 of 222 (21.2%) patients treated with nucleoside analog RT inhibitor (NRTI) antiretroviral therapy but was identified very rarely from drug-naïve individuals. Molecular clones carrying a 3-amino-acid duplication, APPAPP (transframe duplication SPTSPT in p6(Pol)), displayed a delay in protein maturation; however, they packaged a 34% excess of RT and exhibited a marked competitive growth advantage in the presence of NRTIs. This phenotype is reminiscent of the inoculum effect described in bacteriology, where a larger input, or a greater infectivity of an organism with a wild-type antimicrobial target, leads to escape from drug pressure and a higher MIC in vitro. Though the mechanism by which the PTAP region participates in viral maturation is not known, duplication of this proline-rich motif could improve assembly and packaging at membrane locations, resulting in the observed phenotype of increased infectivity and drug resistance.

Amino Acid Sequence↗

PubMed2001

Infectious disease serologic survey in free-ranging Venezuelan anacondas (Eunectes murinus).

Reptiles can harbor pathogenic microorganisms asymptomatically and serve as potential reservoirs of infection for humans, domestic animals, and other reptiles. Infectious diseases are also problematic for free-ranging reptile populations and are an important consideration in reptile reintroduction and translocation projects. There have been limited serologic studies of free-ranging reptiles for evidence of exposure to potential pathogens. In the present study, serum or plasma samples from five male and five female free-ranging Venezuelan anacondas (Eunectes murinus) were screened for antibodies to eastern, western, and Venezuelan equine encephalitis viruses, vesicular stomatitis virus, ophidian paramyxovirus, 19 Leptospira interrogans serovars, and Cryptosporidium serpentes. Antibodies to these agents were not detected, or antibody titers were low and possibly nonspecific. These results for the limited number of anacondas surveyed suggest that they do not serve as significant reservoirs for these infectious agents at this location.

Animals↗

PubMed2001

[Clinical and molecular study of Chilean patients with McCune-Albright syndrome].

BACKGROUND: McCune-Albright Syndrome (MAS) is characterized by precocious puberty, "cafe au lait" skin lesions and polyostotic fibrous dysplasia. It is caused by 4 post-zygotic mutations of G alpha s protein with a mosaic distribution. AIM: To describe the clinical presentation and to investigate the presence of the Arg by his substitution (R201H) in 14 girls with MAS. PATIENTS AND METHODS: We performed a clinical analysis of the patients and specific allele PCR in DNA obtained from leukocytes. RESULTS: Twelve of 14 patients presented with precocious puberty, one with cyclical vaginal bleeding and one with pathological bone fractures. Eight girls had polyostotic fibrous dysplasia, one had hyperthyroidism, four had pathological fractures, ten had ovarian cysts, six had breast hyperpigmentation and ten had "cafe au lait" skin lesions. We detected the R2O1H mutation in 10 of 14 patients. We found no difference in the severity of symptoms or in the age of presentation between the patients with and without the mutation. CONCLUSIONS: The R201H mutation can be detected in white blood cells, in approximately 70% of cases. Patients exhibit wide clinical variability with the same molecular defect. This suggests that tissues have different proportions of mutant cells.

Adolescent↗

PubMed2000

Virological and immunological characteristics of HIV treatment failure.

BACKGROUND: Resistance to antiretroviral treatment is prevalent. There is limited knowledge of the determinants of disease evolution in subjects infected with multidrug-resistant HIV (MDR-HIV). METHODS: Infectivity, replication, chemokine receptor usage, and env, gag, protease and reverse transcriptase sequence analysis was performed for MDR-HIV isolates from 14 HIV-infected individuals and compared to wild-type HIV isolates from individuals naive to antiretroviral treatment. Expression of CD45RO/RA, Ki67 and interferon-gamma and CD4 proliferative response to various antigens was determined for individuals infected with MDR-HIV and compared to that in individuals with optimal suppression of viral replication. RESULTS: Infectivity and replication are diminished for various MDR-HIV isolates, usually in the context of an increase in CD4 and CD4+CD45RA+ T-cell counts. However, a number of MDR-HIV isolates are associated with high in vivo viraemia and pronounced immunosuppression, and display in vitro levels of infectivity and replication comparable to those of wild-type strains. No specific genetic sequence or chemokine receptor usage predicted the fitness of an MDR isolate. CONCLUSIONS: Despite the biological diversity of resistant viruses and the range of host responses observed, our descriptive analysis indicates that viral factors play a role in determining the degree of immune damage observed in the context of MDR-HIV infection.

Adult↗

PubMed2000

Localization of NADPH diaphorase/nitric oxide synthase and choline acetyltransferase in the spinal cord of the frog, Rana perezi.

The localization of nitrergic cells and fibers and cholinergic cells has been analyzed in the spinal cord of the anuran amphibian Rana perezi. Histochemistry for nicotinamide adenine dinucleotide phosphate-diaphorase and nitric oxide synthase immunohistochemistry revealed a concurrent pattern of labeled structures. A large population of nitrergic spinal neurons was found from the level of the obex to the filum terminale. They are abundant in the dorsal horn and intermediate gray matter, but also occur in territories of the ventral horn and, only occasionally, in somatic motoneurons. Numerous nitrergic fibers were present in the spinal white matter, particularly in the dorsal and dorsolateral funiculi. A special arrangement of nitrergic axons is present in Lissauer's tract, where a collateral system is formed. Cholinergic cells, revealed by choline acetyltransferase immunohistochemistry, were observed throughout the spinal cord. The somatic motoneurons were the most conspicuously immunoreactive cells. A large population of cholinergic cells forms a discontinuous column in the intermediate gray, from the third spinal segment to lumbar segments. These cells were organized in a medially located or intercalated cell group, and a laterally located intermediolateral group. Numerous scattered cholinergic cells were present in the central zone of the ventral horn and were absent in the dorsal horn. Double-labeling experiments revealed a high degree of codistribution of nitrergic and cholinergic cells, mainly in the intermediate gray, but colocalization of both markers in the same neurons was not found. This result contrasts with the situation found in mammals and raises the question of whether coexpression of both substances was acquired in spinal cord neurons through evolution only in amniotes or, even, only in mammals.

Acetylcholine↗

PubMed2000

[Determinant factors of smoking cessation during pregnancy].

BACKGROUND: To investigate sociodemographic factors and smoking habit characteristics associated with spontaneous smoking cessation during pregnancy. DESIGN SUBJECTS AND METHODS: Cross-sectional study including 726 pregnant smoking women who attended the antenatal clinic of the Vall d'Hebron University Hospital in Barcelona between July and December 1997 and who agreed to participate were studied. Information was obtained by a structured questionnaire which included items on age, educational level, marital status, previous and current smoking habit, partner smoking habit and partner's attitude towards the smoking habit of the pregnant woman. RESULTS: At the first antenatal visit, 19.7% of women had given up smoking spontaneously. Light smokers (between 1 and 9 daily cigarettes; OR = 4.74) or moderate smokers (between 10 and 19 daily cigarettes; OR = 2.20) were more likely to stop smoking compared to heavy smokers (more than 20 daily cigarettes). If the partner did not smoke, smoking cessation was more likely among pregnant women (OR = 1.78). At the first antenatal visit, among those women who carried on smoking during pregnancy, there was a significative reduction in cigarette consumption of about half the usual daily number of cigarettes smoked. CONCLUSIONS: One out of five pregnant women give up smoking spontaneously during pregnancy from the moment they know they were pregnant until the first antenatal visit. Women who are less likely to stop smoking during pregnancy are those who smoke a larger number of cigarettes. Family environment is an important influential factor in the smoking habit of the pregnant woman.

Adult↗

PubMed2000

Effect of chain length of HAV-VP3 synthetic peptides on its interaction with biomembrane models.

Shorter analogues of a continuous epitope of hepatitis A virus, VP3(110-121) peptide, failed to react with convalescent sera, indicating the importance of the entire peptide in the epitope structure. To better understand the influence of the structural properties of this 12-mer peptide epitope on its biological activity, the interaction of smaller peptide analogues with phospholipid biomembrane models was investigated by a combination of spectroscopic and biophysical techniques. In this article we describe our findings concerning the surface activity and the interaction of peptides with simple mono- and bilayer membranes composed of a zwitterionic phospholipid (dipalmitoyl phosphatidylcholine, DPPC), an anionic phospholipid (dipalmitoyl phosphatidylglicerol, DPPG), or a DPPC/DPPG mixture. The results indicate that the net negative charge of the peptide is in some way responsible of the specific interactions between VP3(110-121) and membrane phospholipids, and necessary to induce beta-type conformations upon vesicle interaction.

Capsid↗