[Antibiotic resistance, plasmid profile and ribotyping in Cuban Shigella sonnei strains].
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Cuba↗
Biomedical subjects
L Bravo
Publications and source records attributed to L Bravo.
[Antimicrobial susceptibility of no-O1 Vibrio cholerae strains isolated from patients in Cuba].
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Cuba↗
Dietary modulation of bacterial fermentative capacity by edible seaweeds in rats.
The effect of edible seaweeds [nori (Porphyra tenera) and wakame (Undaria pinnatifida)] on the modulation of colonic microbiota was studied in adult male Wistar rats. Each alga was fed to rats as the only source of dietary fiber and compared with cellulose. After 12 days, animals were sacrificed and cecal contents used as inoculum to ferment lactulose, citrus pectin, cellulose, nori, and wakame in vitro. Dietary treatment did not affect food intake or food efficiency, yet alga caused a significant increase in cecal weight. Nori and wakame were poorly fermented by the cellulose inoculum, with intermediate substrate degradation (76 and 57% for nori and wakame, respectively) and low metabolism to short-chain fatty acids (SCFA) (30% fermentability compared with lactulose). Cecal contents from rats fed nori and wakame showed a reduced ability to ferment all of the studied substrates compared with the cellulose inoculum, causing a reduction in SCFA production and dry matter disappearance. Only nori induced a bacterial adaptation that brought about a higher fermentation of this substrate. The different behaviors of the two algae could be due to their distinct chemical compositions. In conclusion, nondigestible components of edible seaweeds modified the metabolic activity of intestinal microflora, leading to a reduction of its fermentative capacity.
Animals↗
Association of dietary antioxidants on the severity of gastritis in a high risk population.
PURPOSE: This study is to examine the role of dietary antioxidant intake on the severity of gastritis at the baseline in an intervention study, Chemoprevention of Gastric Dysplasia.METHODS: The Chemoprevention of Gastric Dysplasia is an intervention study conducted in the towns of Pasto and Tuquerres, Colombia. A 79-item food frequency questionnaire was administered to 1,219 subjects at baseline. Endoscopic screening for precancerous gastric lesions was performed in all subjects by biopsy and histologic diagnosis. Subjects without adequate diagnostic material (n = 18) and subjects identified as histologically normal (n = 12) or with gastric cancer (n = 4) were excluded from these analyses. Analysis of Variance on logarithm-transformed data was conducted on dietary antioxidants and the stages of gastritis (atrophic gastritis, intestinal metaplasia, and gastric dysplasia).RESULTS: After adjusting for age, body mass index, smoking status, year of education, total calorie intake, and H-pylori infection status, dietary vitamin C and vitamin E were found to be inversely associated with the severity of gastritis (p < 0.05). Decreased dietary alpha-carotene was found to be marginally associated with gastric dysplasia. Data were then stratified by town where subjects were recruited. The trends for the observed associations were apparent for dietary alpha-carotene, vitamin C and E. However, the association was significant only for vitamin C in Pasto. Compared to subjects with atrophic gastritis, subjects diagnosed with gastric dysplasia have an approximately 15% lower intake of vitamin C.CONCLUSIONS: This study confirmed the protective effect of specific dietary antioxidants on the severity of gastritis. Dietary vitamin C, and to a lesser extent, dietary vitamin E are potentially important for the prevention of gastric cancer.
Journal Article↗
In vitro determination of the indigestible fraction in foods: an alternative to dietary fiber analysis.
Dietary fiber (DF) intakes in Western countries only accounts for about one-third of the substrates required for colonic bacterial cell turnover. There is a general trend among nutritionists to extend the DF concept to include all food constituents reaching the colon. In this line, a method to quantify the major nondigestible components in plant foods, namely, the indigestible fraction (IF), is presented. Analytical conditions for IF determination are close to physiological. Samples, analyzed as eaten, were successively incubated with pepsin and alpha-amylase; after centrifugation and dialysis, insoluble and soluble IFs were obtained. IF values include DF, resistant starch, resistant protein, and other associated compounds. IF contents determined in common foods (cereals, legumes, vegetables, and fruits) were higher than DF contents. Calculated IF intakes were close to the estimated amount of substrates reaching the colon. IF data could be more useful than DF data from a nutritional point of view; therefore, IF is proposed as an alternative to DF for food labeling and food composition tables.
Dietary Fiber↗
Antioxidant activity of dietary polyphenols as determined by a modified ferric reducing/antioxidant power assay.
Most nonenzymatic antioxidant activity (scavenging of free radicals, inhibition of lipid peroxidation, etc.) is mediated by redox reactions. The antioxidant (AO) activity of polyphenols (PPs), as ferric-reducing power, was determined for the first time using a modified FRAP (ferric reducing/antioxidant power) assay. Reaction was followed for 30 min, and both Fe(II) standards and samples were dissolved in the same solvent to allow comparison. Selected representative PPs included flavonoids (quercetin, rutin, and catechin), resveratrol, tannic acid, and phenolic acids (gallic, caffeic, and ferulic). Carotenoids (beta-carotene and zeaxanthine), ascorbic acid, Trolox, and BHA were included for comparison. Equivalent concentration 1 (EC(1)), as the concentration of AO with a reducing effect equivalent to 1 mmol/L Fe(II), was used to compare AO efficiency. PPs had lower EC(1) values, and therefore higher reducing power, than ascorbic acid and Trolox. Tannic acid and quercetin had the highest AO capacity followed by gallic and caffeic acids. Resveratrol showed the lowest reducing effect. Carotenoids had no ferric reducing ability. Polyphenol's AO efficiency seemed to depend on the extent of hydroxylation and conjugation.
Antioxidants↗
Specific detection of Plesiomonas shigelloides isolated from aquatic environments, animals and human diarrhoeal cases by PCR based on 23S rRNA gene.
Twenty-five strains of Plesiomonas shigelloides isolated from aquatic environment, 10 strains from human cases of diarrhoea and five strains from animals were identified by the polymerase chain reaction technique based on 23S rRNA gene. For this purpose, two primers targeted against part of the 5' half of the 23S rRNA gene of P. shigelloides (Escherichia coli number C-912, G-1195; Plesiomonas number C-906, G-1189) were designed. Results from our study indicated that this method might serve as a tool for a rapid and sensitive identification of P. shigelloides from different environmental and clinical sources.
Animals↗
Preliminary assessment of the safety and immunogenicity of a new CTXPhi-negative, hemagglutinin/protease-defective El Tor strain as a cholera vaccine candidate.
Vibrio cholerae 638 (El Tor, Ogawa), a new CTXPhi-negative hemagglutinin/protease-defective strain that is a cholera vaccine candidate, was examined for safety and immunogenicity in healthy adult volunteers. In a double-blind placebo-controlled study, no significant adverse reactions were observed in volunteers ingesting strain 638. Four volunteers of 42 who ingested strain 638 and 1 of 14 who received placebo experienced loose stools. The strain strongly colonized the human small bowel, as evidenced by its isolation from the stools of 37 of 42 volunteers. V. cholerae 638, at doses ranging from 4 x 10(7) to 2 x 10(9) vibrios, elicited significant serum vibriocidal antibody and anti-Ogawa immunoglobulin A antibody secreting cell responses.
Adult↗
Cardiovascular effects of lovastatin in normotensive and spontaneously hypertensive rats.
1. Lovastatin (1, 1.5, and 2 mg/kg) decreased systolic (SBP) and diastolic blood pressure (DBP) in spontaneously hypertensive rats (SHRs) and did not modify the basal values of blood pressure in normotensive rats. 2. Lovastatin decreased heart rate in a dose-dependent manner, and significant effects were observed in SHRs 180 min after lovastatin administration. 3. Lovastatin did not act as a diuretic drug at any of the doses used. 4. Lovastatin (10[-6] M-3 x 10[-4] M) depresses contractions evoked by KCl (80 mM) in isolated thoracic aorta from SHRs and WRs and had almost no relaxant effects on NA-induced (10[-5] M) contractions. 5. It is concluded that the main antihypertensive mechanism of lovastatin is due to the relaxation of rat aorta by inhibiting Ca2+ influx through voltage-sensitive calcium channels.
Animals↗
Polyphenols: chemistry, dietary sources, metabolism, and nutritional significance.
Polyphenols constitute one of the most numerous and ubiquitous groups of plant metabolites and are an integral part of both human and animal diets. Ranging from simple phenolic molecules to highly polymerized compounds with molecular weights of greater than 30,000 Da, the occurrence of this complex group of substances in plant foods is extremely variable. Polyphenols traditionally have been considered antinutrients by animal nutritionists, because of the adverse effect of tannins, one type of polyphenol, on protein digestibility. However, recent interest in food phenolics has increased greatly, owing to their antioxidant capacity (free radical scavenging and metal chelating activities) and their possible beneficial implications in human health, such as in the treatment and prevention of cancer, cardiovascular disease, and other pathologies. Much of the literature refers to a single group of plant phenolics, the flavonoids. This review offers an overview of the nutritional effects of the main groups of polyphenolic compounds, including their metabolism, effects on nutrient bioavailability, and antioxidant activity, as well as a brief description of the chemistry of polyphenols and their occurrence in plant foods.
Animals↗
The new DTPw-HBV-Hib combination vaccine can be used at the who schedule with a monovalent dose of hepatitis B vaccine at birth.
An open, randomized, clinical trial was conducted in order to assess the reactogenicity and immunogenicity of DTPw-HBV and Haemophilus influenzae type b (Hib) vaccines when given either as a mixed administration or as separate concomitant injections using the WHO schedule at 6, 10 and 14 weeks of age, following a dose of HBV at birth. There were no clinically relevant differences in the immune response to any component between the mixed and separate administrations. In fact the anti-tetanus GMTs were significantly higher (p=0.002) in mixed administration (3.9 IU/ml) compared with the separate administration (1.9 IU/ml). However although all subjects achieved anti-PRP titers > or = 0.15 microg/ml, higher anti-PRP GMTs were seen in the group receiving the separate administration. Importantly, the addition of Hib did not adversely alter the reactogenicity profile of DTPw-HBV. This report which demonstrates that this novel combination can be used in WHO recommended schedule.
Analysis of Variance↗
Characterization of Plesiomonas shigelloides from diarrheic children.
Infrastructure of 29 P. shigelloides strains isolated as the only positive finding from children with diarrhea (biochemical properties, antigenic structure, antigenic relationship to shigellae, ATB susceptibility and plasmids) were described. A big variety of 22 serovars in a relatively small number of strains was found, inclusive four new 0 (093, 094, 095 and 096) and one new H (H46) antigen. Some strains belonged to the so-called "Schubert antigenic scheme" the serovars of which come of surface water of small ponds in Germany.
Child↗
[Application of pyrazinamidase activity for the identification of Aeromonas species].
70 Aeromonas strains isolated from patients with acute diarrheal disease were classified into species by using the CAMP factor test and the Pyrazinamidase activity. It is stressed the high percent of coincidence between both tests, which are easy to make at the clinical microbiology laboratories.
Aeromonas↗
[Comparative study of 4 methods for identifying species of the genus Aeromonas].
It is given an explanation of the results obtained with the following methods: AEROKEY II, AEROKEY II + Abbot's scheme, Api 20 NE, and the Biolog System. The study was conducted with 38 strains of Aeromonas isolated from children under 5 with acute diarrheal disease (ADD). The AEROKEY II + Abbot's scheme proved to be the best identification method.
Acute Disease↗
Effect of silymarin on different acute inflammation models and on leukocyte migration.
In-vivo anti-inflammatory activity of silymarin was tested in different acute inflammation experimental models. In carrageenan-induced paw oedema in rats, silymarin given orally reduced in a dose-dependent manner the food-pad abscesses (ED50 = 62.42 mg kg-1). In xylene-induced ear mouse inflammation, silymarin applied topically was more effective than administered intraperitoneally, with effects comparable with those of indomethacin. Silymarin also produced a dose-dependent inhibition of leukocyte accumulation in inflammatory exudates following intraperitoneal injection of carrageenan in mice; silymarin significantly reduced the number of neutrophils. Silymarin was unable to inhibit phospholipase A2 in an in-vitro assay. Besides its known anti-oxidative properties and its ability to act as a radical scavenger, these results suggest that silymarin exerts an important anti-inflammatory action in-vivo by reducing oedema with the effect markedly influenced by the inhibition of neutrophil migration into the inflamed site.
Animals↗
Serum granulocyte colony-stimulating factor (G-CSF) and interleukin-1 (IL-1) concentrations after chemotherapy-induced neutropenia in normal and tumor-bearing dogs.
Hematopoiesis is regulated by complex interactions of hematopoietic growth factors known as colony-stimulating factors and interleukins. We used sensitive bioassays to quantitate serum granulocyte colony-stimulating factor (G-CSF) and interleukin-1 (IL-1) concentrations in normal and tumor-bearing dogs following administration of myelosuppressive chemotherapy (vincristine, doxorubicin, cyclophosphamide). Serum G-CSF and IL-1 increased during the neutrophil nadir in 13 of the 16 dogs. Serum G-CSF concentrations were significantly increased in normal and in tumor-bearing dogs on neutropenic compared to non-neutropenic days. Serum IL-1 concentrations increased significantly on neutropenic days in normal dogs but not in tumor-bearing dogs. A marked neutrophilia was observed in normal dogs, but not in tumor-bearing dogs, following the increases in serum G-CSF and IL-1 concentrations (days 7, 8, and 9, p < 0.05). Normal dogs produced significantly more G-CSF on neutropenic days compared to dogs with lymphoma. On non-neutropenic days, serum IL-1 concentrations were significantly increased in dogs with lymphoma and in dogs with nonlymphoid malignancies compared to normal dogs. These results suggest an important role for G-CSF and IL-1 in hematopoietic recovery after chemotherapy-induced myelosuppression and document an altered hematopoietic regulation in animals with malignancy compared to normal subjects.
Animals↗
Detección de Escherichia coli toxigénica (LT) mediante la reacción en cadena de la polimerasa [The detection of toxigenic Escherichia coli (LT) by the polymerase chain reaction].
In this paper it is described the detection enteroxigenic Escherichia coli LT (+). This method is based on the amplification of a DNA fragment of 400 pairs of bases by polymerase chain reaction (PRC). The oligonucleotides were designed by the authors and the characteristic patterns were observed when the samples were submitted to an electrophoresis in an Agarose gel at 2%. The PCR had positive results with the strains of Escherichia coli 0:149 K; 88 (LT+) collection and with 20 strains isolated from patients with acute diarrhea. Negative results were found in Escherichia coli 0:101 K:99 NM (ST+), Vibrio cholerae 01 and Aeromonas hydrophila.
Aeromonas hydrophila↗
Cytoprotective and antisecretory activity of a ranitidine-zinc complex.
The effects of a ranitidine-zinc complex and ranitidine alone were compared in three different experimental models (pyloric ligation, ethanol and indomethacin) of gastric ulceration in the rat. In the pyloric ligation model, the ranitidine-zinc complex (50, 100 and 150 mg/kg p.o.) showed antiulcerogenic activity similar to that observed with equimolar doses of ranitidine (35, 70 and 105 mg/kg p.o.). Both the ranitidine-zinc complex and ranitidine significantly reduced (p < 0.05) gastric acid secretion in a dose-dependent manner. The protective effect of the ranitidine-zinc complex (100 and 150 mg/kg p.o.) against gastric damage developing after p.o. administration of absolute ethanol or indomethacin was enhanced (p < 0.05) with respect to that obtained with equimolar doses of ranitidine (70 and 105 mg/kg p.o.). The presence of zinc in the ranitidine-zinc complex does not interfere with the antisecretory effects of ranitidine on the gastric mucosa, while it confers an additional cytoprotective action to the final compound.
Animals↗