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Biomedical subjects

M Chamorro

Publications and source records attributed to M Chamorro.

33 records · Page 2Linked to original sources
PubMed1992

Human immunodeficiency virus type 1 gag-pol frameshifting is dependent on downstream mRNA secondary structure: demonstration by expression in vivo.

The human immunodeficiency virus type 1 (HIV-1) Gag-Pol fusion polyprotein is produced via ribosomal frameshifting. Previous studies in vitro and in Saccharomyces cerevisiae have argued against a significant role for RNA secondary structure 3' of the shift site, in contrast with other systems, in which such structure has been shown to be required. Here we show, by expressing the HIV-1 gag-pol domain in cultured vertebrate cells, that a stem-loop structure 3' of the HIV-1 shift site is indeed important for wild-type levels of frameshifting in vivo.

Amino Acid Sequence↗
PubMed1992

[Anthropometric evaluation of the nutritional status of a elderly group from Madrid (Spain)].

Body composition was assessed by means of anthropometry in a group of 75 elderly people (21 men and 54 women), aged 65 to 95 years (mean age 82.1 +/- 0.7) (x +/- SE), mean weight 58.5 +/- 1.7 kg and mean height 150.4 +/- 1.1 cm, which live in al Old People's Home in the Autonomic Community of Madrid. The average Quetelet Index 25.7 +/- 0.7 kg/m2 indicates a basically normal situation although there are 21% obese elderly with Quetelet over 30 kg/m2 and 12% of the cases with the index under 20 kg/m2. Even though the skinfold thickness in our population is inferior to the results obtained in other studies, the triceps skinfold is nearer the values given by other authors, and the suprailiac skinfold is completely different. This means that the elderly studied have less abdominal fat accumulation and more accumulation in arms and legs. This fat distribution can be beneficial in relationship to the risk of suffering several pathologies. Of the males, 15% and 22% of the females have their weight 25% and 30%, respectively, higher than their ideal weight. But there are also some of them with ponderal deficiency; by this means, 23% have 95% lesser than their ideal weight, indicating moderate malnutrition. A total of 16% have less than 85%, indicating medium malnutrition and 2 have less than 75% of the ideal weight, which is indicating of severe deficiency. With age, the measured height, weight, skinfolds, circumferences and diameters, the fat and lean body mass values decrease, the abdominal skinfold and the fat body mass decreasing significantly. Our results can contribute to increase knowledge as to the nutritional status and body composition of the Spanish elderly, and emphasize the coexistence of fat and ponderal excess with deficiencies of higher or lower importance.

Age Factors↗
PubMed1992

[Effect of nutrition on the functional capacity of a group of elderly Spaniards].

The present study analyzes the influence of the nutritional status on the functional capability of 11 institutionalized elderly living in Madrid (Spain). Nutritional status was evaluated by dietetic, anthropometric, hematological and biochemical data and functional status was evaluated considering adiposity, strength in hands and legs bent and stretched and flexibility. The most important nutritional problems that conditional functional wastages are obesity, hypercholesterolemia and protein and micronutrient deficiency. The adverse influence of obesity and hypercholesterolemia on the functional capacity of the elderly is shown by the inverse relationship between flexibility and strength in hands and legs with the adiposity degree, with the thickness of skin folds and the cholesterolemia. In reference to the diet's influence, there are positive correlations between food intake and most of the nutrients with hand and legs strength, and there are statistical significances for proteins, iron, zinc, magnesium and pyridoxine, and also for vitamin C, niacin, thiamin, folic acid and vitamin E. For blood values, the mayor correlation exists between functional parameters and iron, ferritin and vitamin C levels. Our results contribute to confirm the influence of nutrition on the functional capacity of the influence of nutrition on the functional capacity of the elderly and manifest the necessity of improving the elderly's diet, to prevent micronutrient deficiency and also the necessity of increasing their physical activity. Both measures will mean an important help for sanitary and functional improvement of the elderly.

Aged↗
PubMed1991

[Colo-hepatic fistula secondary to hydatid disease. Clinical case].

The fistulization of a hepatic hydatid cyst to the colon is a very rare complication and only two cases have been described in the medical literature. We report a 49 year-old male in whom this complication was suspected in the preoperative period. He was submitted to a cystotomy and colonic exteriorization. Recovery was uneventful.

Colonic Diseases↗
PubMed1988

Minus-strand RNA synthesis in the spinal cords of mice persistently infected with Theiler's virus.

Theiler's virus, a murine picornavirus, causes a chronic neurological disease characterized by primary demyelination in SJL/J mice. The lesions are very reminiscent of those of multiple sclerosis. Theiler's virus persists in oligodendrocytes and to a lesser extent in astrocytes and macrophages throughout the disease. Viral RNA and capsid protein syntheses are minimal in these cells. This restriction could play a central role in the mechanism of virus persistence. By quantitating plus- and minus-strand RNAs in infected central nervous system cells, we showed that RNA replication was blocked at the level of minus-strand RNA synthesis.

Animals↗
PubMed1987

Identification of Theiler's virus infected cells in the central nervous system of the mouse during demyelinating disease.

Theiler's virus is a picornavirus responsible for a persistent, demyelinating infection of mouse central nervous system. We examined the nature of infected cells during the course of this disease using a simultaneous immunoperoxidase-in situ hybridization assay. Cell types were identified with antigenic markers and infected cells were recognized by the presence of viral RNA. We found that, depending on the animal, approximately 10% of infected cells were migroglia-macrophages, 5 to 10% were astrocytes and 25 to 40% were oligodendrocytes. Approximately half of the infected cells could not be identified.

Animals↗
PubMed1986

Alanine and lactate as gluconeogenic substrates during late gestation.

Rates of alanine incorporation into glucose by isolated liver cells of fed rats are 5-fold higher than those observed when lactate was used as substrate. The rates of gluconeogenesis from alanine and lactate in isolated liver cells of fed pregnant rats increase 50 and 200-400%, respectively, over virgins during the last 3 days of gestation. The results support the existence of an increase in the alanine-glucose cycle in the late pregnancy as an important homeostatic pathway in the supply of glucose to the growing fetus.

Alanine↗
PubMed1986

Demyelinating lesions due to Theiler's virus are associated with ongoing central nervous system infection.

We used in situ hybridization and immunocytochemistry to look for a correlation between virus expression and white matter lesions during late demyelinating disease due to persistent Theiler's virus infection. We found the following. (i) Tissue lesions developed at the site of virus infection. This correlation was not explained by infection of lymphocytes and macrophages. (ii) Large differences in the extent of pathology existed between mice. The amount of inflammation paralleled the number of cells containing viral RNA or viral capsid antigens. (iii) C57BL/6 mice, which are resistant to demyelination, were able to eradicate the infection. Our results are strongly in favor of a mechanism of demyelination in which viral gene products play a central role.

Animals↗
PubMed1986

Quantitation, with a new assay, of Theiler's virus capsid protein in the central nervous system of mice.

We developed a quantitative assay for antigens at the single-cell level. Tissue sections were reacted with a primary antibody, a biotinylated secondary antibody, or 35S-streptavidin. Binding of streptavidin to cells was quantitated by microscopic autoradiography. We showed that the number of autoradiographic grains was proportional to the amount of antigen per cell. With this assay, we studied the synthesis of Theiler's virus capsid proteins VP1, VP2, and VP3 in permissive BHK cells grown in vitro and in mouse central nervous system (CNS) cells during a persistent infection. We found that synthesis of the three capsid proteins was restricted in mouse CNS cells. Restricted virus replication could play a major role in the persistence of Theiler's virus in mouse CNS cells.

Animals↗
PubMed1986

Theiler's virus genome is closely related to that of encephalomyocarditis virus, the prototype cardiovirus.

Theiler's virus causes a persistent demyelinating infection of the mouse central nervous system. Our study of the molecular mechanism of persistence led us to sequence 1925 nucleotides located at the 3' end of the viral genome. We observed extensive homologies between this region and the corresponding region of encephalomyocarditis virus, the prototype cardiovirus, and only some homologies with the 3' ends of foot-and-mouth disease virus, rhinovirus, and poliovirus genomes.

Amino Acid Sequence↗
PubMed1985

Theiler's virus RNA and protein synthesis in the central nervous system of demyelinating mice.

We studied Theiler's virus RNA and capsid protein synthesis in sections of mouse spinal cord using in situ hybridization coupled to immunoperoxidase. We found that the majority of infected cells contain 100 to 500 viral genomes and no detectable capsid antigens. Similarly, baby hamster kidney (BHK) cells, which are permissive to Theiler's virus, do not synthesize capsid if they contain less than 1000 viral genomes. Our results demonstrate that virus multiplication is restricted in vivo at the level of RNA replication. They suggest that RNA restriction is sufficient to explain the lack of capsid antigen synthesis.

Animals↗
PubMedDate not supplied

Toxocara seroprevalence in children from a subtropical city in Argentina.

Most studies from Argentina have focused on toxocariasis as an environmental problem of big cities, and there are no available data about children infection from small or middle-sized cities. In order to assess the prevalence of anti-Toxocara antibodies in infantile population, 206 children from Resistencia, of both sexes, aged 1-14 years old were studied by Elisa testing with E/S T. canis L2 antigens. Hematological parameters and immunoglobulin levels were determined; five days' stool samples were studied and epidemiological data were obtained by means of a questionnaire to parents. Results showed that 73% of the children had one or more dogs living at home, 57% reported geophagia and 37.9% were positive for Toxocara serology, but there was no significant difference in prevalence neither for boys and girls, nor concerning age. An increased risk of infection was observed in age groups 5-6 and 7-8 for boys, and in age groups 3-4 and 5-6 for girls.

Adolescent↗
PubMedDate not supplied

Desensitization to azathioprine.

Azathioprine is an immunosuppressant drug which is an analog to 6-mercaptopurine and has been used in the last 20 years to prevent organ transplant rejection. It has also been used in the treatment of some autoimmunological diseases. We present a case of a 24-year-old woman with systemic lupus erythematosus, suffering from nephritis, who developed angioedema after using azathioprine to control her illness. She had never reported similar episodes. The involvement of the drug was demonstrated by positive oral challenge test without changes in biochemical and complement blood determinations. She reached tolerance to the drug after a desensitization procedure (increasing 5 mg each day to reach 125 mg daily). We are not able to propose the involvement of an IgE-mediated mechanism, but rather a hypersensitive one with a non-dose-dependent effect. These desensitization procedures show great potential as therapeutic safeguards against harmful drugs in some patients. We have not found any other desensitization procedure for this drug.

Adult↗