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Biomedical subjects

A Nieto

Publications and source records attributed to A Nieto.

At least 181 records · Page 10Linked to original sources
PubMed1993

Temperature and androgens regulate the biosynthesis of secretory proteins from rabbit cauda epididymidis.

We have compared the biosynthesis of secretory proteins in rabbit cauda epididymidis maintained for 15 days at abdominal temperature with that of the scrotal cauda. Explants from both situations were incubated in vitro in the presence of [35S] methionine, and the labelled proteins released into the incubation medium were analyzed by polyacrylamide gel electrophoresis. Body temperature specifically inhibited the synthesis of at least two polypeptides of 43 kDa and 21 kDa (designated EP21), whereas the synthesis of polypeptides of 80, 39, 31, and 24 kDa was increased. These changes resembled those produced by castration, but androgen treatment was not able to reverse the effect of body temperature. To confirm these observations, poly(A)+ RNA from the scrotal and the abdominal cauda respectively, was translated in vitro and the synthesized products were immunoprecipitated with an antibody against EP21 polypeptide. Both castration and body temperature strongly decreased the concentration of EP21 mRNA. In vivo testosterone administration restored the content of EP21 mRNA in cauda from castrated animals, but not in cauda maintained at body temperature. The changes observed might be related to the adverse effect of body temperature on sperm storage in the cauda epididymidis.

Animals↗
PubMed1993

Cloning and characterization of the SEC18 gene from Candida albicans.

The SEC18 gene product is required for protein transport at different stages in the Saccharomyces cerevisiae secretory pathway. The homologous SEC18 gene from Candida albicans has been cloned by complementation of a sec18-1 S. cerevisiae thermosensitive mutant using a C. albicans genomic library in YRp7. Sequence analysis of the gene revealed a 2382-bp open reading frame which coded for a protein of 88,926 kDa. By an in vitro transcription-translation coupled reaction of the C. albicans SEC18 gene, a protein of approximately 85 kDa was obtained. Hydrophobicity analysis of the protein did not show any predicted signal sequence nor transmembrane anchor domain. These results and the fact that glycosylation was absent in the protein indicated that C. albicans Sec18p did not enter in the secretory pathway. The alignment of the amino acid sequence revealed that the SEC18 gene from C. albicans was homologous to the SEC18 from S. cerevisiae (50% amino acid identity) and to the gene that coded the N-ethylmaleimide-sensitive factor (NSF) protein (43% amino acid identity). Moreover, the C. albicans Sec18p also showed the putative ATP binding site present in S. cerevisiae Sec18p and in NSF.

Adenosine Triphosphatases↗
PubMed1993

Progestin challenge test in postmenopausal patients.

OBJECTIVES: The purpose of this study is to analyze the characteristics of patients identified with the progestin test. METHODS: We administered the progestin challenge test to 157 postmenopausal women and compared the characteristics of the patients who bled, with those who did not. RESULTS: Bleeding occurred in 14.01% of cases and we found that the number of patients who bled were significantly and independently more overweight, had higher levels of plasma estradiol, had a clear presence of superficial cells in the vaginal epithelium and had been menopausal for fewer years than those who did not bleed. CONCLUSIONS: We concluded that the test identifies women at risk from hormone-related endometrial cancer.

Endometrial Neoplasms↗
PubMed1993

High performance latex reagent for hydatid serology using an Echinococcus granulosus lipoprotein antigen fraction purified from cyst fluid in one step.

A lipoprotein fraction from fertile bovine hydatid cyst fluid (FBHCF) was isolated by affinity chromatography on acrylic-heparin. The heparin-binding lipoprotein fraction (HBLF) was proved to be free from host immunoglobulins and albumin. Immunoblotting with confirmed human hydatid sera showed that the major relevant diagnostic bands in FBHCF were also present in HBLF. HBLF or FBHCF were used to sensitize polystyrene latex particles. HBLF-latex showed both higher reactivity with positive hydatid human sera and higher batch-to-batch reproducibility than FBHCF-latex. Titration of sera from 119 surgically confirmed hydatid patients, 48 with other parasitic diseases, 6 with unrelated diseases and 37 healthy subjects was performed using HBLF-latex and conventional ELISA (using FBHCF). Sensitivity and specificity were 83 and 87% for ELISA and 87 and 88% for HBLF-latex. These results indicate that, while being simpler and faster to perform, the HBLF-latex has a similar diagnostic value to that of the conventional ELISA test.

Agglutination Tests↗
PubMed1993

[Visceral leishmaniasis located in the intestines in patients with human immunodeficiency virus infection: a report of 2 cases].

We discuss two cases of visceral leishmaniasis (VL) with intestinal invasion in patients diagnosed of infection due to human immunodeficiency virus (HIV). The onset was as diarrheic manifestation associated to a constitutional syndrome, with no fever. One of the patients responded to treatment with antimonials, while the other died. References on this subject are scarce, being found on a literature search two similar cases as the ones described by us. We think that with every diarrheic process in HIV+ patients, VL diagnosis should be considered, and an intestinal biopsy should be performed.

AIDS-Related Opportunistic Infections↗
PubMed1993

[Tuberculosis and human immunodeficiency virus infection. A prospective study of 215 patients].

We analyze the cases of 215 adult patients affected from tuberculosis (TB) and infection due to human immunodeficiency virus (HIV) in the study period from December 6th, 1986 to January 31st of 1992. Disease affected specially the group of drug addict patients (DAP) with a 74.88%, followed by paid plasma donors (PPD) from our city with a 12.09%. Sexual transmission was the route of contamination with the HIV in 16 cases. In five cases atypical mycobacteria were detected. First-line anti-tuberculostatics drugs activity against Mycobacterium tuberculosis was excellent. A total of 17 cases with toxicity to any of these drugs were described. TB was located in the lung in 108 cases (50.23%), in 74 cases out of the lung (34.41%) and in 33 cases there was intrapulmonary as well as extrapulmonary affectation (15.34%). TB was diagnosed at the same time that a disease which met AIDS criteria in 13.49% of cases, TB was diagnosed first in 32.55% of cases, and AIDS was diagnosed before TB in only 7.91% of cases. Fever was the predominant symptom (88.84%), together with toxic status at admittance (80.47%) and deteriorated immune situation with lymphocytes count decrease (mean 1240/mm) and CD4 (mean value 134.5/mm) together with a mean raised IgA (492.85 mg/dl). Thorax radiography was normal in 34.88%. In 33 of these patients TB was localized in the lung, in 27.91% primary radiologic types were observed while in 31.16% reactivation types. In 51 cases (23.72%) tuberculosis was detected in patients (DAP) who were forwarded from the penitentiary system.(ABSTRACT TRUNCATED AT 250 WORDS)

AIDS-Related Opportunistic Infections↗
PubMed1993

[Mycobacteriosis from Mycobacterium szulgai in a patient with human immunodeficiency virus infection].

We present a case of renal and, probably, bone mycobacteriosis by M. szulgai in a patient infected by the human immunodeficiency virus (HIV). M. szulgai is an atypical skotochromogen mycobacterium rarely described in the literature. Clinically, it is characterized by the predominance of pulmonary manifestations undistinguishables from M. tuberculosis, and rarely affecting other organs. In our environment, such mycobacterium has never been isolated in the main series published in the literature. The evolution of the patient was good, disappearing the clinical signs after the tuberculostatic treatment. The antibiogram showed resistance to rifampicine, piracinamide and ethambutol.

Aged↗
PubMed1992

Tissue-specific and hormonally regulated expression of the puromycin N-acetyltransferase-encoding gene under control of the rabbit uteroglobin promoter in transgenic mice.

Transgenic mice bearing two fragments of the rabbit uteroglobin 5'-flanking region fused to the new reporter gene (pac) encoding puromycin N-acetyltransferase (PAC) showed a different pattern of expression. Transgenic lines (C0.4) harboring a 404-bp fragment (-396/+8) had a uterus-specific expression slightly inducible by estrogen, lacking detectable expression in other tissues where the uteroglobin-encoding gene is naturally expressed in rabbit. Transgenic lines (C3.2) bearing a longer fragment of 3.2-kb (-3254/+8) showed hormonally regulated expression in the uterus and the male genital tract, and detectable expression in the lung. In addition, the nonstimulated uterine expression of the transgene was higher in C0.4 lines than in C3.2 lines. It could be concluded that all sequences required for uterus-specific expression should be present within the 404-bp fragment, and that other upstream (-396) sequences are responsible for expression in the lung and male genital tract, as well as for a possible down modulation of expression in the uterus.

Acetyltransferases↗
PubMed1992

Creutzfeldt-Jakob disease cosegregates with the codon 178Asn PRNP mutation in families of European origin.

We recently discovered an amino acid-altering heterozygous mutation in codon 178 of the PRNP amyloid precursor gene in patients with familial Creutzfeldt-Jakob disease. This mutation is now shown to be associated with the occurrence of disease in 7 unrelated families of Western European origin, among which a total of 65 members are known to have died from Creutzfeldt-Jakob disease. The mutation was detected in each of 17 tested patients, including at least 1 affected member of each family, and in 16 of 36 of their first-degree relatives, but not in affected families with other mutations, patients with the nonfamilial form of the disease, or 83 healthy control individuals. Linkage analysis in two informative families yielded a lod score of 5.30, which, because no recombinants were found, strongly suggests that codon 178Asn is the actual disease mutation.

Adult↗
PubMed1992

Preliminary characterization of anticomplementary components of hydatid cyst fluid.

Sheep hydatid cyst fluid (SHCF) was fractionated on Sephacryl HR S-200 and the anticomplementary activity (alpha-C activity) determined in the fractions obtained; 67% of total alpha-C activity of SHCF was recovered in the void volume fraction (SHCF-I) which contained 61% of SHCF carbohydrates. The bulk of the activity of SHCF-I was eluted by FPLC chromatofocusing on Mono P HR at pH 5.9. After heating at 100 degrees C for 15 min, SHCF and SHCF-I conserved 74 and 54%, respectively of their alpha-C activity. In addition, 37 and 11% of SHCF and SHCF-I alpha-C activity, respectively bound to Protein A. Components not bound to Protein A (SHCFPA and SHCF-IPA) were fractionated on Con A-Sepharose; 71 and 65%, respectively of their total alpha-C activity was retained by this lectin indicating the presence of alpha-D mannoside and alpha-D glucoside residues in the active molecules. Our results suggest that SHCF could contain two classes of alpha-C components: immune complexes and thermoresistant molecules with high carbohydrate content.

Animals↗
PubMed1992

Familial Creutzfeldt-Jakob disease in Chile is associated with the codon 200 mutation of the PRNP amyloid precursor gene on chromosome 20.

We have found the codon 200Lys mutation in 6 Chilean CJD families, including a family in the rural case cluster in Chillán. Thus, all 3 of the known clusters of CJD, in Slovakia, Libyan-born Israeli Jews, and Chile, are linked to the presence of the same mutation. The phenotypic features of the disease in these families are similar to those reported for other clustered or individual families elsewhere in the world. The heterogeneous genetic composition of the Chilean population interpreted in light of historical migration patterns suggests that the mutation may have entered Chile by Jewish emigration from Spain.

Adult↗
PubMed1992

Detection and hormonal regulation of the mRNA for cytosolic phosphoenolpyruvate carboxykinase in rat lung.

We have studied the presence of the messenger RNA (mRNA) for the cytosolic enzyme, phosphoenolpyruvate carboxykinase (PEPCK), in rat lung by Northern blot hybridization to a complementary DNA (cDNA) probe. Lung from normal rats contained substantial amounts of this mRNA, although its relative concentration was approximately six times lower than in liver. Fasting produced an eightfold increase in the content of the enzyme mRNA in lung, which could be reverted to normal values by glucose refeeding. Induced diabetes also resulted in a sevenfold increase of the levels of PEPCK mRNA in lung. Dexamethasone, thyroid hormone, dibutyryl cyclic adenosine monophosphate (cAMP), histamine, and serotonin also induced important accumulations of the enzyme mRNA without affecting the concentration of beta-tubulin mRNA measured as reference. Thus, the PEPCK gene appears to be regulated in a similar manner in lung and liver. The results suggest that PEPCK may be involved in lung metabolism in starvation, diabetes, and other specific hormonal situations.

Animals↗
PubMed1992

Nuclear transport of influenza virus polymerase PA protein.

The subcellular distribution of influenza polymerase PA subunit has been studied using a SV40-recombinant virus (SVPA76), which allows the expression and accumulation of this protein in COS-1 cells. In contrast to the complete nuclear localization observed for the PA subunit several hours after influenza virus infection, when COS-1 cells were infected with the SVPA76 recombinant, the PA protein accumulated either in the nucleus, in the cytoplasm or was distributed throughout the cell. When cells were infected with the SVPA76 recombinant and superinfected with influenza virus, a clear increase in the proportion of cells showing nuclear localization of the PA protein was observed, suggesting that some trans-factor may be required to allow complete nuclear accumulation of the protein. Double infections using SVPA76 recombinant and either SVPB1 or SVNS recombinant viruses showed a complete correlation between expression of polymerase PB1 subunit or NS1 protein and nuclear localization of polymerase PA subunit. However, no such correlation was observed in the double infections of SVPA76 and SVNP recombinants. These results suggest that polymerase PB1 subunit and the non-structural proteins could be involved in the nuclear targeting or nuclear retention of influenza polymerase PA protein.

Animals↗
PubMed1992

Hemispheric specialization for word classes with visual presentations and lexical decision task.

In the present paper we study the possible RH capabilities for the processing of adjectives and verbs of high frequency and medium imagery using a lexical decision task and a horizontal display. In the analysis of both RTs and mean errors, a RVF advantage is obtained. The interaction VF x Word Class did not reach significance. Therefore, we did not find evidence of differences in the visual-field effect for any syntactic class. These results support a LH superiority for the processing of both adjectives and verbs. For the nonword conditions (pseudoverbs and pseudoadjectives), no visual field differences were observed in either group. Methodological aspects are also discussed.

Adult↗
PubMed1992

Atypical Creutzfeldt-Jakob disease in an American family with an insert mutation in the PRNP amyloid precursor gene.

An American family of English origin with an unusually early onset and long-duration form of Creutzfeldt-Jakob disease (CJD) had a heterozygous insert mutation in the region of repeating octapeptide coding sequences between codons 51 and 91 of the PRNP gene on chromosome 20. Affected members were 23 to 35 years old at the onset of illnesses that lasted from 4 to 13 years, yet experimental transmission of disease from the proband (11-year duration) produced a typically brief incubation period and duration of illness in each of three inoculated primates. Also, the PrP amyloid protein that accumulates in CJD brain was only barely detectable in extracted brain tissue from one case with massive spongiform change and was undetectable in another case with no spongiform change, perhaps because of epitope shielding by a configurational change in the protein induced by the mutation. Analysis of this and other families with similar inserts suggests that such mutations in the PRNP gene not only predispose to CJD, but also modify its phenotypic expression.

Adult↗