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Biomedical subjects

A Ortega

Publications and source records attributed to A Ortega.

At least 109 records · Page 6Linked to original sources
PubMed1998

[A comparative study between different regimens for administering 2 doses of the Cuban anti-hepatitis B vaccine].

A controlled clinical trial, corresponding to stage 2, was conducted in a population of sound adult males aged 18-23 to evaluate the immunogenicity of 5 schedules of Cuban vaccine against hepatitis B (Heberbiovac-HB [correction of Cheberbiovac-HB]). 5 groups were studied: I (control group 0, 1 and 6 months), II (0 and 2 months), III (0 and 4 months), IV (0 and 6 months), and V (0 and 8 months). The results showed no significant differences as regards the percentage of seroprotection of any of the groups of 2 doses compared with the control of 3 doses. It is concluded that between the first and the second dose there may be a period of time from 2 to 6 months with no need to reinitiate the schedule. This information will serve as a basis for a population based study to determine which schedule is the best to be used.

Adolescent↗
PubMed1998

[Parkinsonian hemi-syndrome as the initial manifestation of supratentorial cystic hemangioblastoma in a patient with Von Hippel-Lindau disease].

INTRODUCTION: Retino-cerebellar hemangioblastomatosis or Von Hippel-Lindau (VHL) disease is a phacomatosis with a dominant autosomal pattern of inheritance, which is characterized by the presence of hemangioblastomas of the central nervous system (cerebellum and spinal medulla), retinal angiomas and tumors (pheochromocytoma, clear cell carcinoma) or cysts of the abdominal viscera. CLINICAL CASE: We present the case of a 22 year old female with Von Hippel-Lindau disease, in whom a cystic hemangioblastoma of the basal ganglia of the left hemisphere was diagnosed when she complained of difficulty in carrying out fine movements of the right hand and tremor for some months. The supratenorial site of cystic hemangioblastomas in the clinical context of Von Hippel-Lindau disease is very rare and clinical presentation of a parkinsonian hemisyndrome is exceptional. In our search through the literature we have found tumors with many types of histology (meningiomas, glial tumors, craniopharyngioma, epidermoid cysts) in the origin of tumoral parkinsonism. CONCLUSIONS: However, we have found no previous case of cystic hemangioblastomas. We also emphasize that there was full resolution of the condition after total removal of the tumour.

Adult↗
PubMed1998

Anthropometry and strength relationship: male-female differences.

Based upon 303 students from the Complutense University at Madrid (100 males and 203 females), aged between 21 and 29 years, the results of nine anthropometric measurements and four strength tests were evaluated. Males and females were analyzed separately in order to determine whether the relationship of body typology to physical performance varies according to gender. Regarding strength, maximum gender differences were observed for pulling strength (females: 53% of male values), followed by hand grip (59%) and vertical jump (66%). In general, correlations among variables were significant (anthropometric, strength, and anthropometric/strength). Principal component analysis revealed, that for women the vertical jump could be interpretated as more dependent on trunk length than on height or body size. Body size was relevant with respect to static strength. For males the vertical jump appeared to be more related to longitudinal dimensions than for females, while static strength had more to do with body mass (weight) than with body size (height).

Adult↗
PubMed1997

Modulation of NF-kappa B, and Bcl-2 in apoptosis induced by cisplatin in HeLa cells.

Cisplatin exposure induces apoptosis in HeLa cells. Since the interaction of this drug with DNA produces reactive oxygen species, we performed an analysis of the oxidative stress-responsive factors AP-1 and NF-kappa B. Although AP-1 levels were not modified during cisplatin exposure, electrophoretic mobility shift assays demonstrated an increase in NF-kappa B DNA binding activity that correlated with a decrease of the inhibitory protein I kappa B alpha and a specific relocalization of c-Rel, as assessed by immunoblotting and immunofluorescence. No changes in the levels or localization of p65 were found. Interestingly, I kappa B alpha relocalized to the nucleus, probably in order to regulate the binding of specific complexes. This process was accompanied by a decrease of the antiapoptotic protein Bcl-2, and a relocalization of p53 protein to the nucleus. Since HeLa cells lost most of their p53 protein due to a specific E6-dependent degradation, cisplatin could be inhibiting this degradation, since the p53 total levels were not increased during the exposure to the drug.

Antineoplastic Agents↗
PubMed1997

Regulation of the Na+-dependent high affinity glutamate/aspartate transporter in cultured Bergmann glia by phorbol esters.

The effects of phorbol 12-tetradecanoyl-13-acetate (TPA) and dibutyryl cAMP on the glutamate transport present in chick Bergmann glial cell (BGC) cultures were examined. TPA produced a significant decrease in [3H]-D-aspartate uptake, while dibutyryl cAMP treatment elicited a slight reduction in the transport. This effect was dose and time dependent and sensitive to staurosporine, a Ca2+/diacylglycerol-dependent protein kinase C (PKC) inhibitor. Long-term exposure of the culture to TPA results in a dramatic fall of the transporter activity and a decrease in the amount of the transporter protein. These findings suggest that PKC is involved in transport modulation and possibly in the regulation of the transporter gene expression.

ATP-Binding Cassette Transporters↗
PubMed1997

NMDA receptors in cultured radial glia.

The expression of the NMDA subtype of glutamate receptors was investigated by Western blot analysis and RT-PCR in cultured chick Bergmann and Müller glial cells. Using subunit-specific antibodies directed to the carboxy terminus of the rat NMDAR2A/B we detected the expression of the NMDAR2 subunit in both kinds of culture. The functional subunit of the NMDA receptor, NMDAR1, was detected by means of RT-PCR. These results, together with our previous functional characterization of NMDA receptors in radial glia, provide conclusive evidence for the expression of functional NMDA receptor/channels in Bergmann and Muller glia cells. Our findings strengthen the notion of a modulatory role of glial cells in synaptic transmission.

Animals↗
PubMed1997

Cost-utility analysis of paclitaxel in combination with cisplatin for patients with advanced ovarian cancer.

The standard treatment for patients with advanced ovarian cancer (AOC) has been cyclophosphamide and cisplatin (CP). Recently, the results of a large randomized comparative trial demonstrated that the combination of paclitaxel and cisplatin (TP) provided a progression-free survival benefit of 5 months. In this study, a cost-utility analysis was performed from a Canadian health care system perspective to estimate the incremental cost-effectiveness of the TP combination. Twelve AOC patients who received treatment with TP were matched for age and disease stage on a 1-to-2 basis with a CP control. Total hospital resource consumption was then collected for all patients. Treatment preferences were estimated from a cohort of 20 patients and 40 healthy female volunteers using the time trade-off technique. The outcomes were then generated through a decision-analytic model. First-line treatment costs with TP were approximately fourfold greater on a per-cycle basis than the CP alternative (Can$1911 vs Can$459). When progression-free survival benefit and patient treatment preferences were incorporated into the analysis, the results of the decision model revealed an incremental cost between Can$12,000 and Can$24,000 per quality-adjusted progression-free year with the TP protocol. Even though the TP combination has a considerably higher drug acquisition cost, the results of the current analysis suggest that this new chemotherapy regimen does provide patients with substantial quality-adjusted progression-free survival benefit at a reasonable cost to the Canadian health care system.

Adult↗
PubMed1997

Neurological disturbances and hyperdynamic shock in a patient with esophagocoloplasty.

A 39-year-old man, with no history of alcohol intake, who had had an esophago-ileo-colo-gastroplasty with ileotransversostomy, developed diplopia, seizures, metabolic acidosis, and cardiac failure and finally refractory hyperdynamic shock. He died 20 h after admission to our intensive care unit from cardiocirculatory collapse. Postmortem results revealed low erythrocyte transketolase activity, which was increased by 22% by in vitro addition of thiamine diphosphate (TDP effect). Cerebral pathology showed the alterations of Wernicke's encephalopathy. We discuss the possible mechanisms of fatal cardiovascular collapse and the unusual presentation of a case without a history of alcoholic intake or clinical malnutrition.

Acidosis↗
PubMed1997

Modulation of immune cell populations and activation markers in the pathogenesis of African swine fever virus infection.

African swine fever (ASF) virus induces immune cell alterations that may be detected by changes in peripheral blood cells phenotypic antigens and activation markers which were examined by flow cytometry, analyzing both cell proportion and/or expression intensity of superficial antigens. These studies were conducted in pigs with experimental acute of chronic ASF infection to determine whether changes among important surface activation markers and phenotypic antigens, and their correlative lymph node status, reflected similar or disparate aspects of immune pathology. In acute infection produced by virulent viruses, macrophage and B lymphocyte populations decreased in peripheral blood after a short activation period at the beginning of the infection. A significative decrease of interleukin 2 receptor (IL 2R) expression was also observed in those pigs. These variations correlated with lymph node cell depletion due to an intense lymphoid cell death by apoptosis, affecting mainly the B lymphocyte subpopulation as determined by immunohistochemistry. Nevertheless, pigs infected with an attenuated isolate undergoing chronic persistent infection, presented a distinct pattern of modification, according with a different clinicopathological evolution. Changes consisted in systemic immune activation coincident with the highest viremia titer, with an augmentation in CD8+ T lymphocyte, macrophage, and B cell populations, and MHC (major histocompatibility complex) antigens. Percentage elevation of circulating immune subpopulations was accompanied by cell accumulation with lymphoid hyperplasia but a conserved distribution of B lymphocytes in lymphoid organs of chronically infected pigs.

Acute Disease↗
PubMed1997

The role of endothelium in the calcium-induced reduction of the contractile response of the rabbit aorta.

1. Increase of Ca2+ concentration in the bath solution diminishes the contractile response of isolated rabbit aorta rings to alpha 1-adrenoceptor agonists and KCl. 2. In intact preparations the contractions of methoxamine and phenylephrine were maximal when a 0.3- to 0.6-mM Ca2+ bath solution was used, and those of KCl were maximal with a 2.5-mM Ca2+ concentration. 3. The contractions of methoxamine and phenylephrine also were decreased by increasing the Ca2+ concentration above 1.25 mM in disrupted endothelium preparations and in those incubated in indomethacin (10(-5) M), N omega-nitro-L-arginine methyl ester (10(-4) M), or methylene blue (10(-6) M). 4. High organ bath Ca2+ concentrations also caused a decrease in KCl contractions using endothelium-denuded and the treated preparations, the responses being similar with 1.25 mM and 2.5-mM Ca2+ in the methylene blue-treated preparations, whereas they were greater with 1.25 mM Ca2+ in the others.

Adrenergic alpha-Agonists↗
PubMed1997

Excitatory amino acid receptors coupled to the phosphoinositide pathway in Bergmann glia.

Glutamate (L-glu) receptors coupled to phosphoinositide hydrolysis in primary cultures of Bergmann cells from chick cerebellum were characterized biochemically and pharmacologically. Both ionotropic and metabotropic receptor agonists stimulated [3H] inositol phosphates accumulation in the following order of potency: QA > NMDA > L-glu > KA approximately QA > AMPA > > t-ACPD. QA showed a biphasic dose-response curve (EC50 = 0.07 and 53 microM), suggesting interaction with two populations of receptors; L-glu was the most efficient agonist. Stimulation by NMDA was blocked by CPP, AP5 and MK-801; that by AMPA and KA was inhibited 100% by CNQX and DNQX, whereas the effect of QA was decreased both by CNQX and the metabotropic antagonist 4-CPG. Stimulation of PIP2 hydrolysis induced by metabotropic L-glu receptor agonist t-ACPD was blocked by 4-CPG but was only moderately inhibited by MCPG. EAA-induced [3H]IPs accumulation was dependent on external Ca2+ and was not affected by nifedipine verapamil, or dantrolene; thapsigargin increased the effect. Results suggest that EAA activate the PI pathway in Bergmann glia through ionotropic (NMDA and AMPA/KA) as well as metabotropic receptor subtypes (t-ACPD) which could act jointly influencing neurotransmission at the parallel fiber-Purkinje cell synapses in the cerebellum.

Animals↗
PubMed1997

Activation of p42 mitogen-activated protein kinase by glutamate in cultured radial glia.

The effect of L-glutamate (Glu) and its structural analogs N-methyl-D-aspartate (NMDA), kainate (KA) and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA), on the activation of p42 mitogen activated protein kinase (MAPK) was examined in cultured chick radial glia cells, namely retinal Muller cells and cerebellar Bergmann cells. Glu, NMDA, AMPA and KA evoked a dose and time dependent increase in MAPK activity. AMPA and KA responses were blocked by 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) whereas NMDA responses were sensitive to 3-[(RS)-2-carboxypiperazin-4-yl)]-propyl-1-phosphonate (CPP) indicating that the increase in MAPK activity is mediated by AMPA/low affinity KA and NMDA subtypes of Glu receptors. The present findings open the possibility of a MAPK cascade involvement in the regulation of Glu-induced gene expression in radial glia.

Animals↗
PubMed1997

Oral autopsy of unidentified burned human remains. A new procedure.

Forensic dentistry plays an increasingly important role in medicolegal investigation and identification procedures. The oral examination may be difficult because of postmortem changes, especially those of carbonized corpses. We present a new technique of oral autopsy that includes a new means of access to the oral cavity designed for application on unidentified burned human remains. This technique preserves the facial configuration of the cadaver, allowing visual recognition by family members or other persons that is fundamental if the antemortem dental records do not exist or are not available. Also, this technique permits adequate work productivity by the forensic team members and can be used in difficult working conditions, such as mass-disaster scenarios.

Autopsy↗
PubMed1997

Genotypic assessment of isoniazid and rifampin resistance in Mycobacterium tuberculosis: a blind study at reference laboratory level.

Progress in understanding the basis of resistance to isoniazid (INH) and rifampin (RMP) has allowed molecular tests for the detection of drug-resistant tuberculosis to be developed. Consecutive isolates (n = 95) of Mycobacterium tuberculosis, from a Spanish reference laboratory investigating outbreaks of multidrug-resistant tuberculosis, were coded and sent to two external laboratories for genotypic analysis of INH and RMP resistance by PCR-single-strand conformation polymorphism (SSCP) analysis of specific regions of four genes: part of the coding sequence of katG and the promoter regions of inhA and ahpC for INH and the RMP resistance region of rpoB. After correction for the presence of outbreak strains and multiple isolates from single patients, RMP resistance was detected successfully by PCR-SSCP in > 96% of the RMP-resistant strains. PCR-SSCP had a sensitivity of 87% for INH resistance detection, and mutations in katG, inhA, katG-inhA, ahpC, and katG-ahpC were identified in 36.8, 31.6, 2.6, 13.2, and 2.6%, respectively, of the unique strains. Specificity was 100%. Molecular detection of resistance to the two main antituberculous drugs, INH and RMP, can be accomplished accurately by using a strategy which limits analysis to four genetic regions. This may allow the expedient analysis of drug resistance by reference laboratories.

Antibiotics, Antitubercular↗
PubMed1997

Impact of the human immunodeficiency virus epidemic on detection of Mycobacterium isolates in a general hospital.

The number of human samples processed in our mycobacteriology laboratory ranged from 148 per 1,000 admissions in 1988 to 263 per 1,000 admissions in 1995 (5.2% were positive). The human immunodeficiency virus (HIV)-positive population contributed 33.3% of all samples, 43.3% of all isolates, and 36% of all new patients. Given that the ratios of the total number of samples to the number of Mycobacterium-positive samples were 18.3:1 in HIV-positive patients and 28:1 in HIV-negative patients, efforts to reduce the laboratory workload should begin with the HIV-negative population.

Disease Outbreaks↗