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Biomedical subjects

A García

Publications and source records attributed to A García.

At least 289 records · Page 16Linked to original sources
PubMed1995

[Adenosquamous carcinoma of minor salivary glands. Reporting a case in the tongue].

Adenosquamous carcinoma of the salivary glands is an unusual neoplasm not unanimously included in many classifications of salivary gland malignancies. A case sited in the oral cavity, within the tongue is reported. Clinical and histopathologic features are described together with a discussion about treatment and behaviour. We also include an updated of literature relating to this entity.

Carcinoma, Adenosquamous↗
PubMed1995

A role for the intermediate affinity IL-2R in the protection against glucocorticoid-induced apoptosis.

Recent work has shown that T lymphocytes undergo apoptosis upon treatment with the glucocorticoid analogue dexamethasone. These cells can be protected from the effect of dexamethasone by interleukin-2 (IL-2) or IL-4. We were interested in analysing whether a transfected cell dependent on three different lymphokines could be protected by them from the effect of dexamethasone. In addition, we took advantage of our cellular system, in which we expressed intermediate- or high-affinity IL-2R independently, to analyse the role of these receptors in the protection from glucocorticoid-induced apoptosis. In this report we show that IL-2 rescues murine T cells expressing exogenous intermediate- (TS1 beta) or high-affinity (TS1 alpha beta) IL-2 receptor (IL-2R) from dexamethasone-induced apoptosis. This result suggests that intermediate-affinity IL-2R alone can replace high-affinity IL-2R for the protection from the effect of dexamethasone. In addition, IL-4 and IL-9 are rescue-factors, as well as IL-2, of glucocorticoid-treated TS1 beta and TS1 alpha beta cells. Our data suggest that the presence of the alpha-chain of the IL-2R is not required for rescue by IL-2 from the effect of dexamethasone. In addition, we show that proliferation is not required for preventing glucocorticoid-induced apoptosis. This result implies a new role for the intermediate-affinity IL-2R.

Animals↗
PubMed1995

[Enzymatic mechanisms of resistance to aminoglycoside antibiotics in gram negative bacilli from Chilean hospitals].

The presence of aminoglycoside modifying enzymes (AMEs) has been investigated, by an agar diffusion method, in 344 strains of aminoglycoside-resistant Gram negative bacilli isolated in different Chilean hospitals. Most of the strains exhibited a combination of enzymatic mechanism of resistance, but two acetylating (AAC(3)II and AAC(6')I) and one phosphorylating (APH(3')I) enzymes were the main mechanism detected in the strains. A significant increase in the frequency of strains producing AAC(6')I, possible due to wide use of amikacin, has been found when results were compared with those of a report published in 1985.

Aminoglycosides↗
PubMed1995

[Cytogenetic alterations found by chromosome analysis and fish technique in two patients with variant chronic lymphocytic leukemia].

Chromosomal studies in CLL have yielded poorer results than in other blood diseases because of the low mitotic index of the B cells. The FISH technique is a very useful tool for trisomy 12 detection in interphase nuclei in CLL, although this method cannot be a substitutive for conventional cytogenetics. The FISH technique was applied in two cases of CLL by means of satellite DNA probing specific for chromosome 12 according to the Oncor S 1370-CF kit protocol. Trisomy 12 was detected, along with other chromosomal abnormalities secondary to this trisomy. Both patients had lymphocyte counts lower than 5.0 x 10(9)/L and their peripheral blood immunophenotype showed 58% lymphocytes with lambda sIg of medium density, co-expressing CD5 and unable to form rosettes with mouse red-cells. Patient no. 1 was 46,XY/47,XY + 12/47,XY + 12,5q-, and patient no. 2 was 46,XX/47,XX + 12,14q-. The presence of secondary anomalies could explain the special clinico-haematological picture, characterised by low lymphocytosis and presence of irregular nuclei in mature lymphocytes, along with the lack of CD23 expression and rosette formation with mouse red-cells. FISH technique combined with chromosome analysis may prove a useful means for diagnosing and recognising variants or specific entities within low-grade lymphoproliferative syndromes.

Aged↗
PubMed1995

[Acute pancreatitis. A prospective epidemiological study in the province of Alicante. A Hospital Group for Study of Digestive Diseases in Alicante].

OBJECTIVE: To gather epidemiological data on acute pancreatitis (AP) in Alicante area. EXPERIMENTAL DESIGN: A prospective study of patients admitted to all public hospitals with AP during 1991. PATIENTS: Patients over 14 years, with elevation of serum amylase and a consistent clinical presentation, or in whom AP was confirmed at laparotomy or postmortem. RESULTS: We identified 473 episodes of AP in 450 patients (236 males and 214 females). The mean age was 59.4 years. The annual incidence was 451 per million habitants/year. The commonest aetiology was biliary (52%) followed by idiopathic forms (24.7%), alcoholic (20.2%) and miscellaneous (2.9%). The overall mortality rate was 5.1%. Male were more frequently affected below 50 years of age (2.4 men/1 woman); the ratio being balanced above this age. Biliary etiology was more frequent in women, (63.5%), while alcoholic forms were more frequent in man (96.8%). 5.1% of patients presented more than one episode of AP during the year analysed. AP involved the 0.58% of the all patients admitted to the hospitals and the 0.14% of the all patients attended in hospital emergencies.

Acute Disease↗
PubMed1995

Identification of coronary artery disease by 99mTc-MIBI myocardial perfusion single photon emission computed tomography: evaluation using Diamond's method and segmental score system.

Three hundred and eighty-one consecutive patients referred to our Nuclear Medicine Service from the Cardiology Department during a period of two years have been studied to evaluate Coronary Artery Disease (CAP) using 99mTc-MIBI single photon emission computed tomography (SPECT). The sensitivity and specificity for detecting CAD in the whole group of patients, referred (n = 161) or not (n = 220) for coronary angiography, were calculated following Diamond's method, and were found to be 87% and 92%, respectively. Diamond's method estimates these values from those obtained in the subset of patients with angiography referral (sensitivity 91% and specificity 85%) and the pattern of SPECT responses of both groups (69% and 52%, respectively). A new segmental score system was used to evaluate the location and extent of CAD in the catheterized group. The sensitivity for detecting individual artery disease was 69% and specificity was 81%. The sensitivity in patients with single, double and triple-vessel disease was 90%, 96% and 89%, respectively. In the subgroup of patients without infarction (n = 66) the sensitivity and specificity were 76% (19/25) and 90% (37/41).

Coronary Angiography↗
PubMed1995

Various patterns of chimerism after allogeneic bone marrow transplantation for advanced chronic lymphocytic leukemia.

Chimerism studies after allogeneic BMT are performed to determine the donor and/or recipient origin of peripheral blood and marrow lymphoid and hematopoietic cells. These studies have been performed mostly in leukemias and aplastic anemia. We report DNA-based chimerism studies in three patients transplanted for advanced CLL from a histocompatible sibling. Following conditioning with chlorambucil, cyclophosphamide and TBI all three successfully engrafted. One has remained in continuous complete remission (CR) with a complete donor chimerism (CDC) for 110 months post-BMT. Another was in mixed chimerism (MC) with minimal residual disease (MRD) at 3 months post-BMT but was in CR and in CDC at 6 months, suggesting that the persistent CLL cells has disappeared between these two studies. The third patient has been in persistent MC since BMT (24 months follow-up), although he is in CR with no evidence of persistent CLL. We postulate that this patient's MC status is due to normal residual recipient lymphohematopoietic cells that survived the conditioning regimen. In conclusion, various patterns of chimerism can be observed in CLL patients after BMT while remaining in CR and with no evidence of residual CLL.

Adult↗
PubMed1994

Holoprosencephaly associated with caudal dysgenesis: a clinical-epidemiological analysis.

We have studied 9 cases with the combination of some form of holoprosencephaly and any degree of caudal dysgenesis. The cases were identified through the Spanish Collaborative Study of Congenital Malformations (ECEMC). Of the 9 cases, 6 infants had an aneuploidy syndrome, one had Meckel syndrome, and 2 cases were of unknown etiology. We determined that the prevalence figure for the association of both conditions in the same child was 0.08 per 10,000 livebirths, and 18.8 times higher for stillbirths (i.e., 1.50/10,000). This prevalence is significantly higher than what would be expected by chance.

Abnormalities, Multiple↗
PubMed1994

Phosphorylation of the alpha subunit of initiation factor 2 correlates with the inhibition of translation following transient cerebral ischaemia in the rat.

Rats were subjected to the standard four-vessel occlusion model of cerebral transient ischaemia (vertebral and carotid arteries) for 15 and 30 min. After a 30 min recirculation period, protein synthesis rate, initiation factor 2 (eIF-2) and guanine nucleotide exchange factor (GEF) activities, and the level of phosphorylation of the alpha subunit of eIF-2 (eIF-2 alpha) were determined in the neocortex region of the brain from sham-operated controls and ischaemic animals. Following reversible cerebral ischaemia, the protein synthesis rate, as measured in a cell-free system, was significantly inhibited (70%) in the ischaemic animals. eIF-2 activity, as measured by its ability to form a ternary complex, also decrease parallel to the decrease in protein synthesis. As eIF-2 activity was assayed in the presence of Mg2+ and GTP-regenerating capacity, the decrease in ternary-complex formation indicated the possible impairment of GEF activity. Since phosphorylated eIF-2 [eIF-2(alpha P)] is a powerful inhibitor of GEF, the levels of phosphorylated eIF-2 alpha were determined, and an increase from 7% phosphorylation in sham control rats to 20% phosphorylation in 15 min and 29% phosphorylation in 30 min in ischaemic rats was observed, providing evidence for a tight correlation of phosphorylation of eIF-2 alpha and inhibition of protein synthesis. Moreover, GEF activity measured in the GDP-exchange assay was in fact inhibited in the ischaemic animals, proving that protein synthesis is impaired by the presence of eIF-2(alpha P), which blocks eIF-2 recycling.

Animals↗
PubMed1994

Effect of zinc, copper and glucocorticoids on metallothionein levels of cultured neurons and astrocytes from rat brain.

The knowledge of brain metallothionein (MT) regulation and especially of MT presence in specific cell types is scarce. Therefore, the effect of several well-known MT inducers, measured by radioimmunoassays using antibodies that cross-react with MT-I and MT-II or specific for MT-I and which do not cross-react with human growth inhibitory factor (GIF or MT-III), has been studied in primary cultures of neurons or astrocytes obtained from rat cerebrum. MT-I levels in glial cells were about ten times higher than those in neuronal cells (538 +/- 194 vs. 49 +/- 16 pg MT-I/micrograms protein, mean +/- S.D. from three separate cell preparations). Increasing the concentration of Zn in the bovine serum albumin (BSA)-containing culture medium up to 50 microM significantly increased MT-I levels by up to 3.5-fold in neurons and 2.5-fold in astrocytes. In contrast, Cu up to 50 microM increased MT-I levels in a saturable manner in both neurons (up to 5-fold) and astrocytes (up to 1.5-fold), the maximum effect occurring at 5 microM Cu. In general, the combination of Zn and Cu further increased MT-I levels. The effect of the metals on MT-I appeared to reflect metal uptake, since MT-I induction was less marked when the BSA concentration in the medium was increased from 2 to 10 mg/ml. Dexamethasone increased MT-I levels in both neurons and astrocytes in vitro in a concentration-dependent manner. Endotoxin, IL-1 and IL-6 did not have a significant effect on glial MT levels at the concentrations studied. The administration of dexamethasone to rats increased MT-I levels in non-frontal cortex, cerebellum, pons+medulla, midbrain and hippocampus, but not in hypothalamus, frontal cortex and striatum. Endotoxin increased liver but not brain MT-I levels. Immunocytochemical studies in adult rat brain preparations with a polyclonal antibody that cross-reacts with MT-I and MT-II indicated that immunostaining was always nuclear in glial cells, whereas in neurons it was nuclear in the cerebral cortex, hippocampus and the granular layer of the cerebellum, and nuclear plus cytoplasmic in Purkinje cells in the cerebellum, hypothalamic nuclei and gigantocellular reticular nucleus in the brain stem. Meninges, choroidal plexus, ependymal and endothelial cells were also MT-immunoreactive.

Analysis of Variance↗
PubMed1994

Physiological significance of the defense response to intense auditory stimulation: a pharmacological blockade study.

This paper examines through pharmacological blockade some questions related to the physiological significance of the defense response to intense auditory stimulation. Nine subjects received intravenous metoprolol (10-15 mg i.v.), intravenous atropine (0.03 mg/kg i.v.), or a saline solution as placebo condition before undertaking a test of the defense response to a distorted sound of 400 Hz frequency, 109 dB intensity, 0.5 sec duration and virtually instantaneous risetime. Dependent variables were continuous (beat-to-beat) heart rate, stroke volume and blood pressure. The results suggest: (1) a vagal origen of the first acceleration and first deceleration and a sympathetic-parasympathetic interaction during the second acceleration and second deceleration of the heart rate response; (2) a blood pressure response pattern characterized by an increase during the first heart rate deceleration (4-11 sec), a posterior decrease coinciding with the second heart rate acceleration (from 12 to 37 sec), and a lighter increase during the second heart rate deceleration (from 38 to 63 sec); and (3) an implication of the baroreceptor reflex, including a baroreceptor mediated inhibition of the parasympathetic cardiac activity during the second accelerative component of the cardiac response.

Acoustic Stimulation↗
PubMed1994

Allelic polymorphism in the coding region of human TCR C alpha gene and characterization of structural variability in the alpha chain constant domain.

An allelic variant of the human TCR C alpha gene, designated C alpha AL, which encodes a structurally different protein product has been characterized. C alpha AL was independently sequenced using polymerase chain reaction (PCR)-amplified TCR C alpha cDNA from various T cell clones derived from a same individual. It differed from the most usual C alpha sequence by two non-synonymous base changes at codons 4 (AAC-->AAG) and 84 (GAA-->GCA) of the C alpha coding region. These changes imply amino acid substitutions Asn-->Lys and Glu-->Ala respectively. An oligotyping method, based on hybridization of allele-specific oligonucleotides to PCR-amplified C alpha DNA, is also described. It was used for differential typing of the two C alpha forms in family and population studies. In each of three T cell clones analyzed from the same donor having two rearranged TCR alpha chain transcripts, C alpha AL was found in only one of the transcripts. In addition, C alpha AL segregated as a co-dominant mendelian allele within the family of this donor. Population analysis was carried out in 73 spanish individuals. Twelve donors (16.4%) were heterozygous, implying that C alpha AL was present in this population sample with an allelic frequency of 0.08. The observed frequencies of C alpha genotypes were those expected for the two alleles being in Hardy-Weinberg equilibrium. This demonstration of structural polymorphism in the constant region of TCR alpha chains provides a useful genetic marker for TCR and disease association studies due to its precise mapping within the C alpha coding region, and its significant frequency in the analyzed population.(ABSTRACT TRUNCATED AT 250 WORDS)

Alleles↗