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Biomedical subjects

L Bravo

Publications and source records attributed to L Bravo.

At least 55 records · Page 3Linked to original sources

Bicyclic thiophenic derivatives as platelet aggregation inhibitors.

The antiplatelet activity of twenty new thiophenic derivatives, grouped in three series, was studied according to the in vitro Born method. The DI50 for the three inducers of platelet aggregation ADP, adrenaline and collagen were calculated. The strong antiplatelet activity found in some of the compounds studied, which is even superior to that of the four classic antiplatelet drugs used is worth mentioning. The structure-activity relationships is discussed.

Adenosine Diphosphate↗

Study of the antiaggregating activity of new phenacyl-piperazine derivatives.

The antiplatelet activity of twelve new derivatives of phenacyl-piperazine was studied. Eight of them proved to be inactive by Born's method. The other four compound partially inhibited the aggregating effects induced by adrenaline and ADP, but did not prevent the effects produced by collagen. Although it was not possible to establish any relationship between chemical structure and antiplatelet activity, it looks as if there is a certain relationship between the analgesic and the antiplatelet effect. The compounds tested did not usually modify bleeding time.

Acetophenones↗

Late retinal reattachment.

Six cases are described in which late reattachment of detached retina occurred 9-16 months after what had been considered to be failed retinal detachment surgery. In all cases reattachment had been associated with partial restoration of vision. No cause for such reattachment can be clearly established, but it is felt that spontaneous separation of the posterior vitreous face with subsequent release of traction from the surface of the retina may be a contributory factor.

Aged↗

[Determination of verotoxins in strains of Escherichia coli O157:H7].

We performed an study to find out the main virulence factor in verotoxigenic Escherichia coli: the production of verotoxins in 50 non sorbitol-fermenting Escherichia coli strains (possible enterohemorrhage) which were isolated from children with acute diarrheas in the City of Havana and referred to the National Reference Laboratory for acute diarrheal diseases in "Pedro Kourí" Institute. By using the agglutination technique with latex particles of E. coli O157:H7, we determined whether the verotoxins belonged to this serotype, we also researched the production of verotoxins in Vero cell culture. Ninety-six percent of the total number of strains were positive in the qualitative determination of this factor which was more frequently observed after 24 hours.

Bacterial Toxins↗

[Plesiomonas shigelloides, a Vibrionaceae to be taken into account].

The antigenic structure and antimicrobial susceptibility were studied in 99 strains isolated from patients with acute diarrhea (6 strains from an outbreak of digestive transmission disease in Santiago de Cuba) and a strain isolated from a patient who died from infections neurological syndrome (INS, meningitis). Four new serotypes (093, 994, 095, 096), which had not been described in the world classification, were identified from the Cuban isolated strains and were included in the International Serotyping Scheme by the International Reference Center located in Prague, Czech Republic. For the first time in Cuba, the circulation of serotypes 017:H11, 011: H2, 023. H1alc, 057: H3 which show cross reaction to Shiguella species was proved. Those strains from the outbreak of digestive disease belonged to serotype 050: H11 and had a thermostable toxin. The first case of infectious neurologic syndrome with Plesionomas shigelloides etiology reported in Cuba was described; the strain corresponded to serotype 050: H11. The worldwide reported pattern of antimicrobial resistance was demonstrated.

Acute Disease↗

[Toxigenic Vibrio cholerae non-01].

The antimicrobial susceptibility and the presence of a heat-stable toxin were researched into 100 non-01 Vibrio cholerae strains sent by 7 different health centers to the National Reference Laboratory of Acute Diarrheal Diseases in "Pedro Kourí" Tropical Medicine Institute. The presence of 20% toxigenic non-01 Vibrio cholerae was detected, a figure substantially higher than that reported in other geographic areas, except for endemic areas. This result will make it possible to set epidemiological alert in Cuba because these strains can be infected by CTX phages (element transporting genes that encode for choleric toxin) which will give such strains an epidemic potential similar to that of the etiologic agent of cholera. The identified strains could be studied as possible cholera vaccine candidates.

Animals↗

[Characterization of cocoa fiber and its effect on the antioxidant capacity of serum in rats].

OBJECTIVES: The aim of this study was to characterize the physico-chemical properties of cocoa fibre (CF), to analyze its polyphenolic content and antioxidant capacity in vitro, and to investigate the effect of the administration of a polyphenolic extract of this cocoa fiber on the antioxidant capacity of the serum in rats. METHODS AND MATERIALS: Dietary fiber (DF) composition and polyphenolic (PP) content of the cocoa fiber were analyzed. The antioxidant capacity of the CF was determined by means of its reduction power (FRAP) and the capacity to scavenge free radicals (ABTS). To evaluate the bioavailability and the antioxidant capacity in vivo of the phenolic compounds of CF, an extract of these compounds was administred in the stomach of the rats with a gastric probe (100 mg PP/kg), taking blood samples at different time intervals. Sera were analyzed by HPLC to determine the presence/absence of PP or PP-metabolites. In orther to evaluate the antioxidant capacity of the serum FRAP and ABTS methods were used. RESULTS: Cocoa fiber was an excellent source of DF, with a high content of total dietary fiber (TDF), over 60% of the dry matter, made up mainly of insoluble dietary fiber (IDF; 83% of TDF). This fiber had just 1.15% of polyphenols, with low antioxidant activity. After intragastric administration of the PP-rich fraction a fast and measurable absorption of the CF polyphenols was observed, being epicatechin the main PP in blood. The absorption of this PP confers a significant, although transitory increase of the serum antioxidant capacity 10-45 minutes post-gavage; after this time, the antioxidant capacity progressively decreased reaching basal levels after 6 h. CONCLUSIONS: Cocoa fiber can be considered as an excellent source of DF, mainly insoluble dietary fiber; therefore, it could be used as an ingredient in fiber-rich functional foods. Besides the benefits derived from its high fiber content, the CF would provide protection against oxidative damage by means of its content in phenolic compounds (epicatechin) wich are absorbed maintaining the antioxidant properties in vivo.

Animals↗

[Handedness, cerebral dysfunction and dyslexia].

A frequency distribution of handedness and its relations with minor signs of neurological dysfunction was studied in a group of 56 dyslexic children and 56 good readers. An unusual frequency of 18% left-handed children in the dyslexic group and the high frequency of soft signs in this lefthanded children, is in concordance with recent hypothesis about the dysgenesic brain origin of dyslexia and lefthandedness, postulated by Galaburda, Geschwind and others. They suggest a distorted cortical development of the brain areas related with linguistic functions, with subsequent expression on verbal language reading ability and handedness.

Brain↗