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Biomedical subjects

A Braga

Publications and source records attributed to A Braga.

At least 19 recordsLinked to original sources
PubMed2006

Alcohol distribution in different postmortem body fluids.

AIMS: The determination of postmortem ethanol is one of the most frequently requested analyses in forensic toxicology and of extreme importance, especially when the concentration is found to be above the legal level for intoxication at one sampling site and below that level at another sampling site. Because of the unavailability of blood samples for toxicological analysis or even contaminated samples, there is an enormous effort to find alternative sampling sites, such as vitreous humor for ethanol analysis. The main purpose of this study was to establish correlations between urine and blood alcohol concentrations collected from different sites and vitreous humor. METHODS: Ethanol concentrations were determined in specimens of heart, subclavian and femoral blood, urine and vitreous humor, collected from 21 cadavers who were victims of different causes of death. Determinations of ethanol were performed in duplicate using capillary gas chromatography/flame ionization detector and headspace techniques. RESULTS: Statistical analysis of the results indicated that there were no significant differences among urine and blood samples collected from different sites compared to vitreous humor. Regarding vitreous humor ethanol concentration, Pearson's correlation coefficient was 0.97 for femoral blood and urine, 0.96 for heart blood and 0.94 for subclavian blood. The results demonstrated that all the fluids tested against vitreous humor significantly correlated with P (associated probability for the used correlation tests) <0.05. CONCLUSIONS: Vitreous humor can be considered as an alternative sample to urine and blood specimens.

Body Fluids↗
PubMed2002

The PORtromb Project: prothrombin G20210A mutation and venous thromboembolism in young people.

Recently a new identified genetic variant in the 3'-untranslated region of the prothrombin gene (G20210A allele) associated with increased plasma prothrombin levels has been linked to an increased risk of venous thromboembolism (VTE). To determine the importance of this G20210A allele as a causative risk factor for VTE in the general population, we analysed the data of an epidemiologic investigation on thrombophilia in young people, the Oporto Thrombophilia Study (PORtromb). Forty cases (mean age: 27 yr old) with a first episode of VTE under 40 yr old, and 100 healthy subjects, were evaluated. Heterozygosity for the G20210A allele was present in 12.5% of VTE cases and in 5% of controls, indicating a possible marginal increase of VTE risk in carriers of the allele (odds ratio: 2.71: 95% CI 0.74-9.95).

3' Untranslated Regions↗
PubMed1999

Knowledge extraction: a comparison between symbolic and connectionist methods.

The use of a linguistic representation for expressing knowledge acquired by learning systems is an important issue as regards to user understanding. Under this assumption, and to make sure that these systems will be welcome and used, several techniques have been developed by the artificial intelligence community, under both the symbolic and the connectionist approaches. This work discusses and investigates three knowledge extraction techniques based on these approaches. The first two techniques, the C4.5 and CN2 symbolic learning algorithms, extract knowledge directly from the data set. The last technique, the TREPAN algorithm extracts knowledge from a previously trained neural network. The CN2 algorithm induces if...then rules from a given data set. The C4.5 algorithm extracts decision trees, although it can also extract ordered rules, from the data set. Decision trees are also the knowledge representation used by the TREPAN algorithm.

Algorithms↗
PubMed1996

[Cerebrospinal fluid in 50 AIDS patients].

Fifty AIDS patients were studied. All patients had anti-HIV antibodies (ELISA) present and met OPAS/Caracas punctuation criteria for AIDS cases in adults. Cerebrospinal fluid (CSF) analysis included pressure, cytology (number of cytomorphological aspects), total protein and electrophoresis, glucose and chloride concentration. Bacteriological and mycological investigations were performed as well as agglutination tests for Cryptococcus. Complement fixation, indirect immunoflorescence, passive hemagglutination and/or ELISA tests were performed for syphilis, toxoplasmosis, viral and fungal infections. All CSF analysis were made in the same laboratory following the same methodology. CSF was altered in 45 cases (90.0%) of the 50 patients studied. The most important alterations observed were: gammaglobulin (55.5%) and total protein (51.1%) increase, hypercytosis (48.9%) and decrease of chloride concentration (40.0%). HIV antibodies were detected in 42 patients (93.3%). Toxomoplamosis, isolated or associated to other agents, was the most frequent opportunistic infection (57.7%). Cerebrospinal fluid should always be examined in AIDS patients with or without neurological symptoms.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Predeposit hemodilution and intra- and post-operative blood salvage in the orthopaedic surgery of brain damaged children.

The advantages of autologous transfusion are nowadays well known. It appears so very important to enlarge to the greatest number of kinds of pathologies, trying to overcome all possible problems and studying every counterindication. In this study, through a strict collaboration among orthopaedics, anaesthesia, transfusion medicine, neurological and pediatric specialists, we studied a peculiar protocol, suitable for enlarging the autologous techniques to brain damaged children and, after a regular application lasted globally for about two years, we did an evaluation of the results.

Adolescent↗
PubMed1991

[Efferent loop syndrome in gastric stump carcinoma. A clinical case].

The Authors describe a case of efferent loop syndrome in a patient with inoperable gastric stump cancer. The resolution of the symptomatology by an anastomosis between afferent and efferent loop in a tract without neoplastic infiltration, permitted a six month good life period to the patient.

Adult↗
PubMed1991

A survey of the necessity of the hospitalization day in an Italian teaching hospital.

To assess the extent of inappropriate hospital use in an adult in-patients population we used a modified version of the Appropriateness Evaluation Protocol (A.E.P.) to evaluate retrospectively a cross-section of 273 patient-days in a large teaching hospital in the Greater Milan area. Overall, 41% were judged to represent inappropriate hospital use on the basis of the protocol's criteria. The rate of inappropriate hospital use was significantly associated with admitting specialty, ranging from 12% for surgery, to 20% for cardiology and to about 60% in psychiatric, geriatrics and neurology departments (p less than 0.01). Hospital days of patients with longer stays were more frequently inappropriate: a statistically significant trend of inappropriateness emerged ranging from 30% among patients with total length of stay (LOS) of 1-10 days to 60% among those with LOS greater than 30 days (p less than 0.01). This study confirms that there is a substantial rate of unnecessary use of hospitals but that such inappropriateness does not seem in most cases to be easily modifiable through "simple" organizational changes.

Adult↗
PubMed1990

Sensitivities of Aeromonas hydrophila cultured from medicinal leeches to oral antibiotics.

Infections associated with medicinal leech application are caused by Aeromonas hydrophila, an organism that resides in the leech gut. We cultured the intestinal tracts of 25 leeches and evaluated the efficacy of oral antibiotics against Aeromonas hydrophila. Cultures of this organism showed no sensitivity to ampicillin and inconsistent sensitivity to cephalothin (equivalent to cephalexin). The Aeromonas hydrophila cultures did show consistent sensitivity to ciprofloxacin, tetracycline, and trimethoprim-sulfamethoxasole. These three antibiotics should be considered if oral antibiotic coverage is used in association with leech application.

Administration, Oral↗
PubMed1989

[Effect of beta blockers with intrinsic sympathomimetic activity on blood pressure and blood lipids in patients with essential hypertension].

The aim of this study was to compare the effects of a beta-blocker (mepindolol) with intrinsic sympathomimetic activity (ISA) to a beta-blocker (metoprolol duriles) without ISA. Hypertensive patients with more than 50 years of age were selected and randomly allocated to receive either 5 mg/day mepindolol (Group A, 10 patients), or 200 mg/day metoprolol duriles (Group B, 9 patients), or placebo (Group C, 10 patients). They were submitted to clinical exam, stress testing and plasma lipids dosage before and after four weeks of treatment. At rest, there were a significant reduction of systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) in all groups. The mean values for SBP, DBP and HR at rest after treatment were respectively: 154.0, 95.5, 73.7 (Group A); 148.8, 94.4, 70.1 (Group B); 153.0, 96.0, 77.8; (Group C). During stress testing, there were a significant reduction of SBP, HR and double product (DP). The DBP remained unchanged. The mean values for SBP, DBP, HR and DP during stress testing after treatment were respectively; 198.0, 115.5, 124.3, 246.9 (Group A); 198.8, 114.4, 144.6, 283.2 (Group B); 202.2, 119.0, 143.5, 283.4 (Group C). Total cholesterol, HDL-cholesterol, and LDL-cholesterol, have not changed with both beta-blockers. There were a significant increase in plasma triglycerides and VLDL-cholesterol levels after treatment with beta-blockers. In conclusion, both mepindolol and metoprolol were similarly effective in reducing arterial blood pressure of hypertensive patients. There were not significant differences between the beta-blocker with or without ISA in regard to their effects on plasma lipids.

Aging↗
PubMed1987

[Demonstration of methicillin-resistant Staphylococci using the broth microdilution method].

The increasing incidence of methicillin resistant staphylococci rendered more important the problem of their detection, by the susceptibility tests, particularly by the broth microdilution methods. The effects of the addition of 2% NaCl to the Cation Supplemented Mueller Hinton Broth (CSMHB) on the MICs of penicillinase resistant penicillins (PRP) and of other antibiotics have been studied on 100 strains of staphylococci isolated by pathological materials. In 13% of the studied strains the MIC of oxacillin in CSMHB plus 2% NaCl was at least 4 times greater than the value found in the absence of NaCl. In the same experimental conditions a ratio between MICs equal or greater than 4 dilutions resulted in 69% of the strains for the gentamicin and in 93% of the strains for the amikacin. Such variation in the value of MIC determined a change in the category of susceptibility (from sensitive to intermediate or resistant and from intermediate to resistant) in 10% of the strains for the oxacillin, in 28% for the gentamicin and 41% for the amikacin. To improve detection of methicillin resistant staphylococci without altering the MICs of other antibiotics (aminoglycosides), it is necessary to perform the broth microdilution tests with CSMHB and with CSMHB plus 2% NaCl. CSMHB plus 2% NaCl will be used for testing PPR and cephalosporin, while CSMHB for the other antibiotics.

Anti-Bacterial Agents↗
PubMed1985

[Comparative study in vitro on the activity of 7 antibiotics against anaerobic bacteria from hospital isolates].

One hundred and ninety-four anaerobic bacteria isolated from clinical sources were tested by agar dilution technique against seven antimicrobial agents. A comparison with international literature, generally used for selecting appropriate antimicrobial drug showed concordant patterns of susceptibility in the case of Cocci gram-positive, Clostridia, Fusobacterium and other species of Bacteroides excluded B. fragilis group. For these strains we did not found any particular problem in the choice of the therapeutic treatment. In the case of Bacteroides fragilis and B. fragilis group our data confirmed the widespread of resistance to clindamycin and cefoxitin. When the cefoxitin and clindamycin resistance is confirmed by in vitro tests, the piperacillin represent a valid alternative considering the safety profile compared to chloramphenicol (no bone marrow toxicity) and to carbenicillin (no sodium load).

Anti-Bacterial Agents↗