Biomedical subjects

R H Vieira

Publications and source records attributed to R H Vieira.

6 recordsLinked to original sources

PubMed2005

Biological relevance of E-cadherin-catenin complex proteins in primary epithelial ovarian tumours.

This study analysed the biological relevance of E-cadherin, alpha-catenin, beta-catenin and gamma-catenin immunoexpression pattern (reduced vs. preserved phenotype) in epithelial ovarian tumours. Immunohistochemistry was used to evaluate the expression of these proteins in 154 epithelial ovarian tumours, consisting of 17 benign, 33 borderline and 104 malignant tumours. In borderline tumours, the immunoexpression pattern of E-cadherin (p = 0.014) and alpha-catenin (p = 0.030) associated with histological type. In malignant tumours, the immunoexpression pattern of E-cadherin was related with histological type (p = 0.001). The immunoexpression pattern of beta-catenin associated with histological type and tumour differentiation (p = 0.005, p = 0.025, respectively). The preserved phenotype of E-cadherin was most frequently observed in mucinous tumours, whereas reduced E-cadherin was most frequently observed in serous tumours. The preserved phenotype of beta-catenin associated with endometrioid carcinomas, while reduced beta-catenin associated with poorly differentiated serous and clear cell carcinomas. Although the reduced phenotype was the most frequent immunoexpression observed for all proteins of the E-cadherin-catenin complex in epithelial ovarian tumours, only beta-catenin showed a significant difference between benign, borderline and malignant tumours (p = 0.045), since borderline and malignant tumours most frequently showed the reduced phenotype. The immunohistochemical profile of beta-catenin was shown to be of biological relevance: reduced beta-catenin was correlated with loss of tumour differentiation and serous carcinomas that are known to depict aggressive biological behaviour in epithelial ovarian tumours.

Adenocarcinoma, Mucinous↗

PubMed2000

Biosorption: a solution to pollution?

To solve the water pollution problem by toxic heavy metal contamination resulting from humans technological activities has for long presented a challenge. Biosorption can be a part of the solution. Some types of biosorbents such as seaweeds, molds, yeasts, bacteria or crab shells are examples of biomass tested for metal biosorption with very encouraging results. The uptake of heavy metals by biomass can in some cases reach up to 50% of the biomass dry weight. New biosorbents can be manipulated for better efficiency and multiple re-use to increase their economic attractiveness.

Adsorption↗

PubMed1998

Survival of Vibrio cholerae 01 strains in shrimp subjected to freezing and boiling.

This research was undertaken to assess the resistance of Vibrio cholerae 01 strains inoculated into white shrimp, Penaeus schimitti, to heating and freezing treatments. Shrimp samples with and without carapace were obtained from Sao Luis, Brazil. Microbial analysis revealed the presence of marine vibrios including Vibrio alginolyticus, Vibrio parahaemolyticus, and other vibrios and aerobic gram-negative and gram-positive bacteria that grew on selective medium, thiosulfate-citrate-bile salt-sucrose agar. Samples with and without carapaces were heated before inoculating with cells of V. cholerae and then one-half of the samples was stored frozen at -200 degrees C and the other one-half was heated to boiling temperatures. Viable cells of the test organism were recovered from samples without carapaces, stored under frozen conditions, after 36 days. In contrast, no living cells were recovered after 26 days from samples with carapaces. Boiling temperatures were very damaging to V. cholerae 01 in shrimp samples with and without carapaces. Total destruction of the cells occurred within 1 to 2 min of exposure to heating.

Animals↗

PubMed1998

Colimetry of marine waters off Fortaleza (Ceará State, Brazil) and detection of enteropathogenic Escherichia coli strains.

Bacteriological analyses of seawater from three main beaches in Fortaleza, Brazil were performed during 1997. Thirty-six samples per beach were collected for a total of 108 samples. For Meireles Beach, 44% of the samples had MPN total coliforms values of at least 1100 or over 2400/100 ml, followed by Formosa and Diários beaches showing lower counts. For fecal coliforms the highest numbers were demonstrated for Formosa, followed by Meireles and Diários beaches in this descending order: 13.0%, 11.1% and 8.3%, respectively. Escherichia coli strains were identified in 76.8% of the 108 samples. Among 295 strains of E. coli, 21 belonged to serogroups O25, O26, O91, O112, O119, O158 and O164. Strains from serogroup O26 were tested using PCR, ELISA and Vero cells to detect Verotoxins VT1 and VT2 and all strains were negative. No LT and ST, as determined by ELISA and suckling mice assays, were detected among the 295 strains. All strains of E. coli were sensitive to ampicillin, cephalothin, gentamicin, tetracycline, sulfametox-trimethoprim, chloramphenicol and ciprofloxacin. Although the E. coli strains were not toxigenic, their presence in high numbers could be of public health significance.

Animals↗

PubMed1997

Coliforms and Salmonella in seawater near to domestic sewage sources in Fortaleza (Ceará, Brazil).

The bacteriological conditions of the coastal region of Fortaleza (Ceará, Brasil), including the coastal zones of the Ceará and Cocó rivers, were examined. The study was conducted during June, September and December 1993, and March 1994. The region was divided into two areas: (i) Direct Influence Area (DIA), consisting of 20 sampling stations located near to discharge zones of the submarine pipeline system, where collections were carried out at the surface, and (ii) Indirect Influence Area (IIA), located near to the coastal zone, including Barra do Ceará, Kartódromo, Volta de Jurema, Mucuripe, Farol and Caça e Pesca beaches, totalling 26 sampling stations. The most probable number (MPN) of both total and fecal coliforms in DIA was positive only in station number 6, near to the sewage discharge exit. The following bacteria were identified: Citrobacter sp., Enterobacter aerogenes and Escherichia coli. Kartódromo beach was contaminated throughout the sampling period. Results of total fecal MPN was essentially lower than 3.0 x 10(2) coliforms/100 ml at Caça e Pesca beach. In December, at both DIA and IIA, Salmonella was identified in several samples. In DIA, the spatial distribution for Salmonella suggests that there should be a coastal sea current from east to west along the coastline. In IIA, Salmonella was identified at Kartódromo and Farol beaches throughout the sampling period.

Atlantic Ocean↗

PubMedDate not supplied

Microbicidal effect of medicinal plant extracts (Psidium guajava Linn. and Carica papaya Linn.) upon bacteria isolated from fish muscle and known to induce diarrhea in children.

Out of the twenty-four samples of shrimp and fish muscle used for this study, twelve were collected near a large marine sewer for waste disposal, 3 km off the coast of Fortaleza (Brazil) and used for the isolation of E. coli. Other twelve were collected at the Mucuripe fresh fish market (Fortaleza, Brazil) and used for the isolation of Staphylococcus aureus. Ethanol, water and acetone-diluted extracts of guava and papaya leaf sprouts were tested on the bacteria in order to verify their microbicidal potential. The E. coli strains used in the trials were rated LT positive. The papaya leaf extracts (Carica papaya Linn) showed no microbicidal activity while the guava sprout extracts (Psidium guajava Linn) displayed halos exceeding 13 mm for both species, an effect considered to be inhibitory by the method employed. Guava sprout extracts by 50% diluted ethanol most effectively inhibited E. coli (EPEC), while those in 50% acetone were less effective. It may be concluded that guava sprout extracts constitute a feasible treatment option for diarrhea caused by E. coli or by S. aureus-produced toxins, due to their quick curative action, easy availability in tropical countries and low cost to the consumer.

Animals↗