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Biomedical subjects

A García

Publications and source records attributed to A García.

At least 253 records · Page 14Linked to original sources
PubMed1996

Characterization of a gastric tumor cell line defective in MHC class I inducibility by both alpha- and gamma-interferon.

Alpha/beta and gamma type interferons (IFN), act through distinct cell surface receptors and induce transcription of an overlapping sets of genes. MHC class I genes are inducible by both type of interferons. We have analyzed a gastric tumor cell line, AGS, which was completely defective in MHC class I response to interferon-alpha and gamma. Northern blot analysis demonstrated that the lack of IFN response was related with the absence of up-regulation of specific HLA class I mRNA. Electrophoretic mobility shift assays in various tumor cell lines after IFN-alpha and IFN-gamma treatment showed differential binding of the transcriptional factors to MHC class I regulatory elements. Comparison of kappa-B binding activity showed that IFN-alpha and IFN-gamma induced opposite changes in NF-kappa B binding activity in AGS cells, indicating that the absence of MHC class I response in AGS appears to be independent of kappa-B activity. In contrast, there were remarkable differences in the level of transcriptional factor binding to an interferon-responsive sequence element (IRSE), between AGS and other interferon-responsive tumor cell lines. This result suggests that the low level of transcriptional factor binding to IRSE in AGS cells was responsible of the lack of induction of MHC class I antigens. In this context, overlapping factors in the signal transduction pathway of both type I and II interferons may be involved in the non-responsiveness of this gastric carcinoma tumor cell line.

Adenocarcinoma↗
PubMed1996

Comparison of two leukocyte extraction methods for cytomegalovirus antigenemia assay.

We carried out a prospective, parallel, and blind study on 113 blood samples from immunocompromised patients in order to compare two leukocyte extraction methods (6% dextran sedimentation and Polymorphprep separation) for cytomegalovirus (CMV) antigenemia assay. CMV was detected in 38 samples by antigenemia assay (34 by dextran sedimentation and 35 by Polymorphprep separation). No differences either in the number of positive specimens (P = 1) or in the mean CMV-positive cell counts (P = 0.41) were observed between the two leukocyte extraction methods. In conclusion, the two methods performed equally well for this assay.

Antigens, Viral↗
PubMed1996

A new case of fibrochondrogenesis from Spain.

A rare, neonatally lethal chondrodysplasia with histological characteristics was first described in 1978 and the authors named the condition fibrochondrogenesis. Here we report the eighth published case of fibrochondrogenesis. This was identified in a population of 1,158,067 consecutive livebirths, so we can assume that this figure should be the minimal prevalence for livebirths.

Abnormalities, Multiple↗
PubMed1996

Delaying and extending sleep during weekends: sleep recovery or circadian effect?

There is a well-known tendency to delay and prolong our sleep during weekends (Saturday and Sunday), with an advance and reduction of sleep during workdays (Monday to Friday). The objective of this work was to determine if the changes of sleep during weekends are produced by a partial sleep deprivation or a lack of entraining of circadian rhythms to an advanced phase, during workdays. The subjects were 52 undergraduate female students, mean age = 17.5 years, SD = 1.32. All students attended school following a regular schedule, from Monday to Friday. Two groups of students were studied: one attended school from 07:00 to 12:00 h (morning group, n = 30); the other attended school from 14:00 to 18:00 (afternoon group, n = 22). None of the students worked or was engaged in other activity with a fixed schedule. All kept a sleep-wake diary for 2 weeks, in which they recorded their bedtimes, wakeup times, and sleep-onset latencies. The morning group delayed 47.4 min [t(29) = 4.72, p < 0.0001] and prolonged their sleep 118.2 min [t(29) = 9.4, p < 0.0001] during weekends. Although the afternoon group had the opportunity to maintain a delayed phase and a long sleep time throughout the week, they delayed their bedtime by 24 min [t(21) = 2.99, p < 0.01] during weekends, without changing their sleep duration. The findings suggest that the prolonged sleep during weekends is due to reduction of sleep during workdays, whereas the delay of bedtime seems to be associated with a tendency of the human circadian system to maintain a delayed phase with respect to the solar daylight period.

Activities of Daily Living↗
PubMed1996

Dietary intervention in a hypercholesterolemic school-aged population from Northern Spain.

A "before and after" intervention study, over a five year period, was done in order to find the degree of compliance to dietary recommendations and their effects on serum lipids in a hypercholesterolemic school-aged population. 383 children between 6 and 13 years of age, were identified with hypercholesterolemia (total serum levels above 4.8 mmol/l), in a previous randomized mass screening of 1095 individuals. Some dietary guidelines aimed at decreasing fat consumption and increasing fiber and carbohydrate ingestion were given to the families, and 226 of the children participated in the follow-up. Changes of address and/or school-center was the main cause of non-participation. The follow-up examination consisted in the evaluation of serum lipids and actual diet. Cholesterol serum levels decreased from a mean value of 5.4 mmol/l to 4.8 mmol/l. 59.3% of the sample had reached serum cholesterol levels below the risk threshold. Fat ingestion diminished significantly (40.3% of calories to 36.7%, p < 0.001), saturated fatty acids decreased from 15.3% of calories to 13.5% (p < 0.001), monounsaturated fatty acids decreased from 17.1% to 15.4% (p < 0.001) and polyunsaturated fatty acids remained unchanged. Carbohydrate consumption increased from 45% of the calories to 47.38% (p < 0.001). Dietary changes were greater in individuals out of risk than those who still had high cholesterol levels. These data indicate a good family compliance to the recommendations and that changes in food habits seem to be effective in controlling hyperlipidemia. Dietary changes are better accepted by younger children.

Adolescent↗
PubMed1996

Association of the shared epitope with radiological severity of rheumatoid arthritis.

OBJECTIVE: To investigate the association between radiological severity of rheumatoid arthritis (RA) and the presence of the shared epitope. METHODS: Ninety unrelated adult Spanish patients with RA with a disease duration of at least 3 years, selected according to the American College of Rheumatology criteria, were radiologically assessed (shoulders, elbows, wrists, hands, hips, knees, and feet) and classified as having severe or nonsevere RA. DNA oligotyping was used to determine DR specificities and to detect DR4 and DR1 alleles. RESULTS: Forty-one patients (45.5%) had severe RA. Sixty-six patients (73.3%) carried the shared epitope and 18 (20%) had double expression of the shared epitope. Thirty-seven (90%) of the 41 patients with severe RA expressed the shared epitope. Logistic regression analysis showed that both single and double expression of the shared epitope were strongly related to the radiological severity of RA (odds ratio = 6.3 and 9.4, respectively). CONCLUSION: Our results show that radiological severity of RA is highly associated to the shared epitope.

Adult↗
PubMed1996

[Familial prevalence in chronic intestinal inflammatory disease. Differences among groups of patients with and without a familial history].

OBJECTIVE: To assess the prevalence of familial occurrence in patients with inflammatory bowel disease and to evaluate the differences among groups of patients with and without familial history. PATIENTS AND METHODS: Complete information about sex, age of onset of inflammatory bowel disease, initial location, extracolonic manifestations and perianal disease (in Crohn's disease) was obtained from 187 patients, 99 with Crohn's disease, and 88 with ulcerative colitis. RESULTS: In 9 patients (9%) with Crohn's disease and 11 (12.5%) with ulcerative colitis, at least one first-degree relative also had inflammatory bowel disease. Three relatives of patients with Crohn's disease had ulcerative colitis and no relative of patients with ulcerative colitis had Crohn's disease. As compared with the group of patients with ulcerative colitis and no familial history, patients with familial history had more frequently distal location and extra-colonic manifestations. No differences were observed among patients with Crohn's disease and familial or non familial history. CONCLUSIONS: Prevalence of inflammatory bowel disease in relatives of patients with Crohn's disease or ulcerative colitis is increased. In ulcerative colitis, it is possible to segregate two different groups according to familial history.

Adolescent↗
PubMed1995

High rate of MDR-1 and heterogeneous pattern of MRP expression without gene amplification in endometrial cancer.

The present study was undertaken to determine the pattern of expression of 2 molecular markers of multidrug resistance, the MDR-1 and MRP genes, in endometrial carcinomas from 50 untreated patients using a PCR semi-quantitative assay. In addition, PCR analysis of MDR-1 and MRP gene amplification was obtained in each case. High rate of MDR-1 expression without gene amplification was detected in all endometrial-carcinoma samples, as well as in 10 adenomatous hyperplasias and 50 samples of normal endometrium. On the other hand, MRP appeared to be expressed at moderate levels in normal endometrial tissue, while relatively high levels of MRP expression without gene amplification were occasionally observed in endometrial-carcinoma samples.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1995

Calcium-dependent nitric oxide formation in glial cells.

We have previously demonstrated nitric oxide (NO)-dependent cyclic GMP (cGMP) formation in response to noradrenaline (NA) and glutamate (GLU) in astrocyte-enriched cultures from rat cerebrum. In the present work we show heterogeneity in agonist responses in astrocyte cultures from cerebellum, hippocampus and cortex. The response to NA was higher in cells from cerebellum, intermediate in cultures from hippocampus and low in cortical astrocytes. GLU had no significant effect in cortical and cerebellar cultures and presented lower effects than NA in cells from hippocampus. The NO donor sodium nitroprusside (SNP) produced much higher cGMP levels than agonists and the order of efficacies was cerebellum > cortex > hippocampus. Responses to NA and SNP in cerebellar astrocytes were sensitive to culture conditions decreasing when cells were seeded at low density or subcultured. Microglial cells were the main contaminants of the cerebellar astrocyte cultures but did not contribute to the NA or the SNP responses. No soluble guanylyl cyclase or calcium-dependent NO synthase (cNOS) activities were detected in microglial cultures. The effect of NA in cerebellar astrocytes was blocked by L-arginine analogues and by the alpha 1-adrenoceptor antagonist prazosin. The calcium ionophore A23187 mimicked the effect of NA and omission of calcium from the medium prevented both responses. NA did not elicit cGMP formation in granule cell cultures. These results support an astroglial location of the alpha 1-adrenoceptors and the cNOS that mediate NA stimulation of cGMP formation in cerebellum.

Animals↗
PubMed1995

Detection of c-erbB-2/neu and fibroblast growth factor-3/INT-2 but not epidermal growth factor receptor gene amplification in endometrial cancer by differential polymerase chain reaction.

BACKGROUND: It currently is well established that the activation of protooncogenes could trigger uncontrolled cell growth and cancer development. Although this correlation already has been evidenced in several human tumors, no conclusive studies have related oncogene activation with the development of endometrial neoplasia. Nevertheless, few reports suggest that c-erbB-2/neu, which is a prognostic marker in breast cancer, epidermal growth factor receptor (EGFR), which is overexpressed in a variety of neoplasms, and fibroblast growth factor-3 (FGF-3/INT-2), which has been found to be amplified in breast and ovarian cancer, could be implicated in the development of endometrial adenocarcinoma. METHODS: Amplification of c-erbB-2/neu, EGFR, and FGF-3/INT-2 was examined in 50 endometrial carcinomas, 10 adenomatous hyperplasias, and 50 normal endometrial samples, using the genomic differential polymerase chain reaction with the single copy reference gene interferon-gamma. Quantitation of the ratios between the amplified bands was assessed by image analysis. RESULTS: c-erbB-2 and FGF-3/INT-2 were amplified in a first group of 7 (14%) and a further group of 7 (14%) patients, respectively, of a total of 50 in whom endometrial cancer had been studied. In the latter seven, a strong correlation between this genetic marker and an advanced disease stage (International Federation of Gynecology and Obstetrics Stage III) was found. In two patients, both genes were amplified. No EGFR gene amplification was detected in any case. CONCLUSION: c-erbB-2/neu but not EGFR gene amplification was detected and FGF-3/INT-2 amplification and advanced disease were correlated in endometrial cancer.

Adenocarcinoma↗
PubMed1995

[Minimal residual disease in chronic myeloid leukemia in patients with long survival after allogeneic bone marrow transplantation].

BACKGROUND: The study of the minimum residual disease in a series of patients diagnosed with chronic myeloid leukemia (CML) treated with non manipulated allogeneic bone marrow transplantation (BMT) reporting a survival longer than 6 months is presented. METHODS: The positivity of the chimeric transcription bcr-abl was studied in 18 long surviving BMT patients. The complementary DNA (cDNA) corresponding to this transcription was amplified by the polymerase chain reaction (PCR) technique. Double internal PCR (PCR nested) was performed to increase the sensitivity of the determination. RESULTS: The first determination was performed in different post BMT stages with a median of 27 months (4-97). Fourteen out the 18 patients were positive for the bcr-abl transcription. On the second determination carried out in 11 cases with a sample obtained 24 months after the first 7 out of the 10 positive cases evaluated presented an identical pattern while the patient who originally was negative, remained so. The original transcription became negative in three patients. Only one of the positive cases developed hematologic relapse during the study period. CONCLUSIONS: Aggressive chemo-radiotherapy does not eradicate the leukemic clone in all patients with chronic myeloid leukemia. The persistence of positive results in a high number of patients with chronic myeloid leukemia in remission for over 6 months after bone marrow transplantation is not predictive of imminent relapse.

Adult↗
PubMed1995

Cyclic GMP inhibition of stimulated phosphoinositide hydrolysis in neuronal cultures.

We used a radioreceptor binding assay to analyse the effect of dibutyryl cyclic GMP (dbcGMP) and the nitric oxide (NO) donor sodium nitroprusside (SNP) on inositol(1,4,5)trisphosphate (Ins(1,4,5)P3) mass accumulation in response to the muscarinic receptor agonist carbachol and K(+)-induced depolarization in neuronal primary cultures. In forebrain neurones carbachol induced a transient rise in Ins(1,4,5)P3 with a maximal increase of about 2.5-fold at 5 s. At this time 30 mM K+ induced a somewhat lower stimulation. Both carbachol and high K+ stimulations were significantly inhibited by dbcGMP and by SNP. The effect of SNP was blocked by haemoglobin. dbcGMP inhibition of the carbachol effect was also observed in cerebellar granule cell cultures. These results show for the first time that the NO/cGMP generating system can modulate phosphoinositide turnover in CNS neurones in a manner similar to that previously reported to occur in peripheral neurones and non-neuronal tissues.

Animals↗