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Biomedical subjects

A Díaz

Publications and source records attributed to A Díaz.

At least 127 records · Page 7Linked to original sources

[Evaluation of stomatological care in Santiago de los Caballeros, Dominican Republic, stage 1].

In Santiago de los Caballeros, Dominican Republic, a study was done of the status of dental care with the long-run aim of reforming the system and increasing the integration of education and service. The study centered on the current status of that integration, which is taking place between the Federal Secretary of Public Health and Social Welfare and the Universidad Católica Madre y Maestra, respectively the service and education establishments concerned. The study is being done in two stages. In the first, carried out in 1983 and described in the article, the chief aim was to assemble information on the system considered. The methodology consisted in the selection of a sample of 61 patients treated at three centers of basic dental care in the area; use of the techniques of direct observation, interviews, measurement of the time spent on each operation, and the building up of files; and a study of all the variables that could have influenced an assessment of the situation at the time and of projections for the future. Some of the variables were the priority group, the age group, health status, progress of the treatment, and the reason for seeking care and choosing the center. It was found that 81,97% of the patients were under 14 years of age and 78,69% were between 5 and 14 years old. Most of the patients said they were in good health, although a high percentage reported having had certain diseases. Of all patients studied, 73,77% were discharged--a satisfactory figure. The main reasons for coming to the center were personal initiative and the recommendation of another, not medical referral, and the reason for choosing the center was its proximity to the patient's home. On the basis of the study the research team recommended a revision of the standards for dental services nationwide, adaptation of the work done to the physical premises, planning for the integration of education and service, the encouragement of innovative attitudes in service and education professionals and, lastly, extension of the manpower training program--with the integration of education and service--to the communities and instead of confining it to intramural instruction.

Dental Care↗

[Purification of kininogen II (LMW) from human plasma].

Plasma supernatant in which kallikrein has been activated and removed by glass powder whilst kininogen I (HMW) has been consumed by the activated kallikrein, was used for the preparation of kininogen II. It was purified by chromatography on DEAE-cellulose followed by gel filtration on G-200 Sephadex. The purification of kininogen II was assessed from determinations of the amount of kinin released (expressed as bradykinin) as measured on the isolated guinea pig ileum, using samples incubated with human salivary kallikrein or trypsin. A preparation of kininogen II containing an activity equivalent to 8 microgram Br/mg protein, was obtained. Salivary kallikrein released approximately three times more kinin from the substrate as compared to trypsin.

Chromatography, DEAE-Cellulose↗

[Purification and enzyme study of kininogens I and II from human plasma].

Kininogens I (HMW) and II (LMW) were isolated and partially purified from human plasma. The disappearance of kininogen I was prevented by the use of hexadimethrine bromide, which inhibits the activation of plasma prekallikrein. The two kininogens were separated by chromatography on DEAE-cellulose. Further purification of kininogen I and II was achieved by separate chromatographic steps of the partially purified kininogens on SP-Sephadex. The purification of the kininogens was controlled by incubation of the respective samples with different kininogenases: human plasma kallikrein, human salivary kallikrein and trypsin. As determined by gel filtration, a molecular weight of 250 000 daltons was found for kininogen I (HMW) and 48 000 daltons for kininogen II (LMW).

Clinical Enzyme Tests↗

[Intranasal approaches for pituitary area tumors. Our experience].

Transsphenoidal approach is the most commonly employed surgical technique for the resection of pituitary tumors. We present our experience in the transnasal-transsphenoidal approach in 30 patients undergoing pituitary surgery from 1998 to 2002. Ten patients underwent surgery via a sublabial-transeptal-transsphenoidal approach, 15 patients via a transeptal-transsphenoidal approach and 5 patients via a pure endoscopic transnasal-transsphenoidal. The pathological study showed 29 pituitary adenomas and 1 Rathe's cleft cyst. We conclude that the pure endoscopic transnasal-transsphenoidal approach guided by a navigator-system is safest and more effective approach. We reserved the transeptal-transsphenoidal approach for cases with obstructive septal deflection and poor pneumatized sphenoid sinuses. We do not recommend the use of the sublabial-trans-sphenoidal approach.

Adult↗

A randomized double-blind clinical trial of two antivenoms in patients bitten by Bothrops atrox in Colombia. The Regional Group on Antivenom Therapy Research (REGATHER).

A randomized double-blind clinical trial in 39 patients envenomed by Bothrops atrox in Antioquia and Chocó, Colombia, was performed to compare the efficacy and safety of 2 equine-derived antivenoms prepared at Instituto Clodomiro Picado, University of Costa Rica. Twenty patients received a monovalent anti-B. atrox antivenom (group A) and 19 patients were treated with a polyvalent (Crotalinae) antivenom (group B). Both antivenoms were equally efficient in the neutralization of the most relevant signs of envenoming (haemorrhage and blood clotting time alteration). Fourteen patients (36%) presented early adverse reactions to antivenoms and no significant difference between the 2 groups was observed. Urticaria (18%) was the most frequent early adverse reaction and there was no life-threatening anaphylactic reaction. Based on clinical criteria and serum venom levels, estimated by an enzyme immunoassay, 15 patients were classified into 2 groups: mild and moderate/severe envenoming. With the antivenom doses used in this study (3, 6 and 9 vials for mild, moderate and severe envenoming, respectively), both antivenoms were equally efficient in clearing serum venom levels within the first hour of treatment, and the levels remained below the lower limit of venom detection for 24 h. Antivenom concentration in serum remained high for up to 24 h after antivenom infusion, suggesting that an excess of antibody in relation to circulating antigen had been administered.

Adolescent↗

Acrosome content release in streptolysin O permeabilized mouse spermatozoa.

Sperm cell plasma membrane and the outer acrosomal membrane fuse profusely during the acrosome reaction. The process is triggered by extracellular signals that elicit several intracellular events leading ultimately to membrane fusion. We have developed a streptolysin O permeabilizing protocol that selectively affects the spermatozoon plasma membrane without causing a significant loss of the acrosomal content. Most of the acrosomal acid phosphatase remained sperm-associated even after a 20 min incubation at 37 degrees C. However, the presence of 100 microM Ca2+ in the incubation buffer stimulates the release of the enzyme. The reaction was followed biochemically, measuring the acid phosphatase activity released to the medium and morphologically by the binding of fluorescein isothiocynate-conjugated peanut agglutinin and by electron microscopy. The results show that the streptolysin O permeabilized spermatozoon is a promising model for studying the complex set of events mediating and regulating the acrosome reaction.

Acid Phosphatase↗

[Detection of antibodies to beta-amyloid in carriers of E280A mutation in the presenilin-1 gene].

OBJECTIVE: To investigate some immune component that could contribute to the pathogenesis of Alzheimer's disease associated with the E280A mutation of the presenilin-1 gene (PS-1). PATIENTS AND METHODS: Serum antibodies against both cardiolipin and beta-amyloid peptides (beta 1-40 and beta 1-42) were quantitated by means of an indirect ELISA technique in carriers of the mutation, either healthy or with Alzheimer's disease, as well as in normal controls without the mutation. RESULTS: Out of 19 patients with Alzheimer's disease only 2 had increased values of antibodies to cardiolipin, namely: one with 14.58 micrograms/ml of IgM and the other with 36.16 micrograms/ml of IgG. The remaining individuals revealed values under 10 micrograms/ml, considered normal, and there was no significant difference between the groups. Significant serum reactivity (p < 0.001) was detected against both beta-amyloid peptides in the mutation carriers, either with or without Alzheimer's disease, as compared to the control group. No correlation was detected between this antibody response and the mental or functional situation of the patients. CONCLUSION: beta-amyloid antibodies, present in the mutation carriers, may simply represent a marker of immune activation induced by beta-amyloid with no in vivo effect; however, despite the results, the possibility can not be ruled out of a pathogenic role of these antibodies in early onset Alzheimer's disease.

Adult↗

[New procedure for the early detection and control of hospital malnutrition].

The serious problem of hospital undernutrition is still being underestimated by medical staff of modern hospitals, despite its impact on clinical evolution and hospitalisation costs. The actual system used to detect undernutrition in hospitals depends on doctor's sensitivity and not even the 10% of the cases that require intervention are detected. The screening methods developed so far are not useful for daily clinical practice due to their low effectiveness/cost ratio. We present a screening method that allows an automatic daily assessment of nutritional status, of all inpatients that undergo routine analysis. The system is based on a computer application that compiles daily all patients' information available in hospital databases, through the internal network. It automatically assesses the nutritional status of patients taking into account laboratory information concerning albumin, total cholesterol and total lymphocyte count. This tool also provides diagnostic and patients data for physicians' usage. The screening method has been validated, obtaining a sensitivity of 92.3 and specificity of 85.0, considering only laboratory information. This is an efficient tool for early detection and permanent control of hospital undernutrition, with the suitable characteristics for these screening functions, such as its sensitivity, specificity, universality, economy and harmlessness, as well as a great versatility for undertaking a high number of studies regarding the hospital undernutrition problem. We trust that working with it we will obtain a remarkable welfare improvement as well as make aware to people in charge of Public Health of the magnitude of the undernutrition's derived consequences of hospital's in-patients, and after discharge.

Adult↗

[Primary adenocarcinoma of the duodenum: a report of 2 cases and a review of the world literature].

We presented two cases of adenocarcinoma of the duodenum diagnosed at the Gastroenterology Unit of the General Hospital of Lidice Dr. Jesús Yerena and reviewed retrospectively the pathology cases from 1980-1990. We review the world literature and found that the most common clinical presentation was as obstructive type. In our cases perforation and jaundice were the presentation.

Adenocarcinoma↗