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M Muñoz

Publications and source records attributed to M Muñoz.

At least 181 records · Page 10Linked to original sources
PubMed1992

Cytochrome oxidase activity in the nucleus of the tractus solitarius of the cat.

We studied the cytochrome oxidase (CO) activity in the nucleus of the tractus solitarius (NTS) of normal cats and in animals subjected to unilateral removal of vagal and glossopharyngeal afferents. In normal cats CO activity was higher in the ventrolateral, dorsolateral, interstitial and ventral NTS subnuclei. The dorsal, medial, commissural and gelatinosus subdivisions showed lower levels of CO activity. The peripheral deafferentation up to 47 days did not reduce the CO activity, suggesting an important role for the central inputs in determining the neural activity of the NTS.

Afferent Pathways↗
PubMed1992

Amino acid sequence and structural properties of protein p12, an African swine fever virus attachment protein.

The gene encoding the African swine fever virus protein p12, which is involved in virus attachment to the host cell, has been mapped and sequenced in the genome of the Vero-adapted virus strain BA71V. The determination of the N-terminal amino acid sequence and the hybridization of oligonucleotide probes derived from this sequence to cloned restriction fragments allowed the mapping of the gene in fragment EcoRI-O, located in the central region of the viral genome. The DNA sequence of an EcoRI-XbaI fragment showed an open reading frame which is predicted to encode a polypeptide of 61 amino acids. The expression of this open reading frame in rabbit reticulocyte lysates and in Escherichia coli gave rise to a 12-kDa polypeptide that was immunoprecipitated with a monoclonal antibody specific for protein p12. The hydrophilicity profile indicated the existence of a stretch of 22 hydrophobic residues in the central part that may anchor the protein in the virus envelope. Three forms of the protein with apparent molecular masses of 17, 12, and 10 kDa in sodium dodecyl sulfate-polyacrylamide gel electrophoresis have been observed, depending on the presence of 2-mercaptoethanol and alkylation with 4-vinylpyridine, indicating that disulfide bonds are responsible for the multimerization of the protein. This result was in agreement with the existence of a cysteine-rich domain in the C-terminal region of the predicted amino acid sequence. The protein was synthesized at late times of infection, and no posttranslational modifications such as glycosylation, phosphorylation, or fatty acid acylation were detected.

African Swine Fever Virus↗
PubMed1992

Cytoarchitecture and ultrastructural characteristics of the area octavolateralis of the urodele amphibian Pleurodeles waltlii.

The cytoarchitecture of the area octavolateralis (AOL) in Pleurodeles waltlii is studied by means of normal stained material. In addition, the main ultrastructural features of the cells in the AOL are described. In the AOL, three columns, one upon the other (dorsal, intermediate and ventral), are present. Each one includes a medially located cell group and lateral neuropil. While rostrally the three are well represented, the dorsal subdivision do not reach the same caudal extent where the intermediate column forms a small lobe. The ultrastructure of the neurons in the AOL reveals similarities with other cell types in the amphibian brain. A comparative analysis of the ultrastructure of vestibular cells with other vertebrates is also discussed.

Animals↗
PubMed1991

Influx and incorporation into protein of L-phenylalanine in the perfused rat pancreas: effects of amino acid deprivation and carbachol.

The rate of protein synthesis in the isolated perfused rat pancreas was measured from the rate of incorporation of L-[3H]phenylalanine into total protein, and was compared with the transport of this amino acid into the epithelium. Unidirectional (15 s) and net (15-30 min) uptake of L-[3H]phenylalanine was measured relative to D-[14C]mannitol (extracellular marker) using a cell loading technique. The fractional rate of protein synthesis in the pancreas was also measured in vivo using a flooding dose technique and found to be 118 +/- 10% day-1 (corresponding to an absolute rate of incorporation of L-Phe into protein of 36.1 +/- 3 nmol min-1 g-1) in overnight fasted rats. Compared with the in vivo rate, the perfused pancreas exhibited a markedly lower rate of protein synthesis which increased significantly when amino acids were added to the perfusate (15.6 +/- 1.9 vs. 22.5 +/- 0.9% day-1 or 4.7 +/- 0.6 vs. 6.9 +/- 0.3 nmol L-Phe min-1 g-1). Carbachol (3 x 10(-7) M) stimulated protein synthesis provided amino acids were also supplied in the perfusate. Protein synthesis rates measured under all conditions in vivo and in vitro were at least an order of magnitude lower than the unidirectional influx (121 +/- 14 nmol min-1 g-1) of L-phenylalanine into the pancreatic epithelium. These results demonstrate that amino acid transport across the basolateral membrane of the epithelium is not rate-limiting for pancreatic protein synthesis.

Amino Acids↗
PubMed1991

Diffuse sclerosing papillary carcinoma of the thyroid gland: immunohistochemical analysis of the local host immune response.

Surgical specimens from four patients with diffuse sclerosing papillary carcinoma of thyroid were examined by electronmicroscopy. In addition, immunohistochemical examination using a panel of monoclonal and polyclonal antibodies was carried out in order to investigate the expression of HLA-DR antigen, the presence of Langerhans' cells and the phenotypic characteristics of the inflammatory infiltrate. The ultrastructural study showed that the intraglandular dissemination, typical of this tumour, was due to massive lymphatic invasion. Many Langerhans' cells were observed among tumour cells and in the lymphoid infiltrates in proximity to tumour foci. HLA-DR expression was seen on macrophages, Langerhans' cells, endothelial cells, lymphoid cells, many tumour cells and in some non-neoplastic follicles close to tumour clusters and lymphoid infiltrates. The immunohistochemical analysis of the inflammatory infiltrates showed a high proportion of B- and T-cells, and moderate numbers of plasma cells. Our results suggest that the tumour-specific immune response can give rise to an autoimmune reaction involving non-neoplastic follicles. It is suggested that this could be one of the mechanisms responsible for immunofacilitation of tumour growth.

Adolescent↗
PubMed1991

Cis-inhibition and trans-stimulation of cationic amino acid transport in the perfused rat pancreas.

Transport of cationic amino acids in the isolated perfused rat pancreas was studied using dual-isotope dilution techniques. At 50 microM substrate concentration, unidirectional tracer uptakes for L-arginine (56 +/- 1%), L-lysine (49 +/- 2%), and L-ornithine (44 +/- 3%) were followed by rapid tracer efflux. In the presence of Na+, influx of L-arginine [Michaelis constant (Km) = 1.74 +/- 0.15 mM, maximum velocity (Vmax) = 1.97 +/- 0.07 mumol.min-1.g-1] and L-lysine (Km = 2.48 +/- 0.17 mM, Vmax = 2.42 +/- 0.08 mumol.min-1.g-1) was mediated by a common transport system, sensitive to cis-inhibition by L-ornithine, 2,4-L-diaminobutyric acid, D-lysine, and D-arginine. Substrates for system A [alpha-(methylamino)isobutyric acid] and an anionic carrier (L-aspartate) were poor cis-inhibitors of L-arginine entry. Removal of Na+ resulted in a 40% reduction in cationic amino acid influx. After cell loading (20 min), L-[3H]-lysine cleared predominantly from a slowly exchanging pool with a rate constant of 5.97 +/- 0.67 min. An influx/efflux permeability ratio of 14.5 +/- 1.6 was determined, and efflux of L-lysine was trans-stimulated by vascular challenges with cationic or large neutral amino acids. The specificity, relative Na+ independence, and exchange properties of this saturable cationic amino acid transporter in the pancreatic epithelium resemble those reported for system y+ in cultured fibroblasts and hepatocytes.

2,4-Dinitrophenol↗
PubMed1991

A general method to cleave a known DNA sequence at any site.

We describe a new method for obtaining DNA fragments starting at a desired point where there is no recognition sequence for any known restriction endonuclease. A single-stranded DNA containing the fragment of interest is annealed to a synthetic oligonucleotide hybridizing at the 5' end of the required fragment. Then, a partially double-stranded DNA is synthesized using the Klenow fragment of DNA polymerase I in the presence of the four deoxynucleoside triphosphates. The remaining single-stranded regions are removed by digestion with a single-strand nuclease, and the resulting 5' blunt-ended fragment is finally released by digestion with a restriction endonuclease at any site downstream its 3' end. The usefulness of the method was exemplified here by insertion of an epidermal growth factor-like African swine fever virus gene immediately downstream of the ribosome binding site of an expression vector.

African Swine Fever Virus↗
PubMed1991

[Compliance with tuberculosis treatment in adults in Santiago, Chile].

A prospective study was conducted to estimate the current magnitude of adherence to short-course tuberculosis treatment, the degree of abandonment, the characteristics of treatment dropouts, and the causes of this abandonment. The study group was made up of tuberculosis patients over the age of 15 who received care at the Western and Southern Health Services of the Metropolitan Region of Santiago, Chile, between 1 October 1987 and 31 January 1988. The percentage abandoning treatment, calculated by the life table method, was 11.5. The profile of patients who dropped out of treatment was as follows: male, under 45 years of age, single, low level of education, no steady work, homeless, and alcoholic. In addition, an opinion survey on the variables associated with abandonment was conducted and it was concluded that the main ones were alcoholism and intolerance to tuberculosis drugs. Awareness of this profile makes it possible to take measures to prevent patients from abandoning treatment, as well as to educate and even hospitalize at the start of treatment those tuberculous patients exhibiting such a profile.

Adolescent↗
PubMed1991

[A new demographic classification of the family for the use in primary health care].

The approach to the health-disease problem in the family requires a knowledge of demographic features. We propose a demographic classification based on the nuclear family. In addition to the extensive and single-parent families, the lack of family and the familial equivalents we subdivide the nuclear family depending on whether it has close relatives or not, the number of children, the existence of extended family or not, with relatives or aggregates, and the binuclear families or those of divorced people. On this basis, we have evaluated the demographic distribution of 917 families from the basic health areas of Albaicín and Cartuja in Granada, the Valle de Jaén, and Telde in Las Palmas. We have found the predominance of the nuclear family (76.8%) over the extensive (5.2%), as well as the relevance of the single-parent (8.9%) and the lack of family (7.7%) types. Among nuclear families, those with relatives in near areas come first (62.2%), followed by the extended type (19.6%). There is a remarkably low rate of numerous families (9.3%), while binuclear families are exceptional. As familial demography is a factor to be considered in clinical practice owing to its influence in the familial function and resources, we propose the routine use of this classification in the family history.

Demography↗
PubMed1990

Rapid and steady-state amino acid transport in perfused human fibroblasts and colon adenocarcinoma cells: effects of methotrexate.

Initial and steady-state uptakes of serine and phenylalanine by human fibroblasts and human colon tumour cells were studied applying a double isotope dilution technique to perfused populations of cultivated cells retained on microcarrier beads. This new method permits the differentiation of the unidirectional transport parameters and can also distinguish between membrane-associated processes and independently intracellular events in isolated cells. High initial L-serine uptake values in colon adenocarcinoma cells became negative under steady-state conditions. To determine if the observed negative L-serine uptake was produced by the rapid efflux of intracellular L-[3H]serine, the cells were treated with methotrexate (MTX) (an inhibitor of cytosolic dihydrofolate reductase). The modified curve of L-[3H]serine uptake after MTX treatment suggests that, under these experimental conditions, net serine transport is non concentrative in colon tumour cells and could be modulated by the rate of intracellular serine metabolism; it also suggests that MTX does not directly affect serine transport in perfused human colon adenocarcinoma cells. Initial and steady-state uptakes of phenylalanine were high in both fibroblasts and tumour cells and were unaffected by MTX treatment.

Adenocarcinoma↗
PubMed1990

Alterations on the distribution of methionine-enkephalin-like in the cat thalamus after electroacupuncture: an immunocytochemical study.

The distribution of methionine-enkephalin-like structures in the cat thalamus after electroacupuncture was studied using an indirect immunoperoxidase technique. We have observed some alterations on the distribution of methionine-enkephalin-like fibres in the thalamus of the cat after electroacupuncture. Thus, in the nuclei habenularis lateralis and lateralis dorsalis, in the tractus mamillo-thalamicus and in the tractus habenulopeduncularis, we have found methionine-enkephalin-like fibres in the animals treated with electroacupuncture, however in such nuclei and tractus no immunoreactivity was observed in the control animals. On the contrary, after electroacupuncture we have not found methionine-enkephalin-like fibres in the thalamic nuclei centrum medianum, parascicularis and subparafascicularis, in which in the animals no pretreated with electroacupuncture, immunoreactive fibres were observed. In other thalamic nuclei such as habenularis medialis, paraventricularis anterior, centralis medialis, medialis dorsalis and in the stria medullaris no alteration on the distribution of immunoreactive fibres was observed in the animals treated with electroacupuncture in comparison with the distribution of such fibres found in the control animals. These observations suggest that the electroacupuncture might induce alterations on the distribution of methionine-enkephalin-like in certain nuclei of the thalamus of the cat.

Animals↗
PubMed1990

[Evaluation of the nutritional status in a population of Andalusian schoolchildren].

The nutritional status of a population of school children was assessed with anthropometric data and information on nutrient intake. The three groups of subjects, all from the area around Vélez Málaga (Málaga-Spain), were aged 6-7, 10-12 and 13-15 years. The data revealed no significant departures from normal anthropometric patterns with the exception of triceps skin fold thickness, which was lower for both sexes in all groups than the normal figure established for these groups in the spanish population. Although no serious imbalances were recorded in nutrient intake, fat intake was higher than the recommended levels for spanish children's, while carbohydrate, fiber, calcium, magnesium, iron and zinc intake was lower in all groups, and vit. B2 intake was lower in the 10-12 years old group.

Adolescent↗
PubMed1990

Electron microscopic observations of the trigeminal mesencephalic nucleus in the frog, Rana ridibunda.

The trigeminal mesencephalic nucleus (Mes V) of the frog Rana ridibunda, has been studied by means of electron microscopic techniques. Mes V neurons are large (20-30 microns in diameter). They are dispersed in the optic tectum and show round to oval cell bodies. Both multipolar and unipolar cells were observed. Their cytoplasm is very rich in organelles with well-developed rough endoplasmic reticulum that forms prominent and scattered Nissl bodies. Numerous small mitochondria, Golgi dyctiosomes, neurotubules and neurofilaments are distributed among the granular endoplasmic reticulum. A striking feature is the existence of abundant lysosome-like particles throughout the cytoplasm. In the surface of Mes V neurons spinous processes are absent and synaptic contacts on the perikarya are scarce. Two types of synapses, one with spherical translucent vesicles and the other with elongated translucent vesicles, contact on either the cell body or the dendrites of Mes V cells.

Animals↗