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Biomedical subjects

M M Rodríguez

Publications and source records attributed to M M Rodríguez.

At least 37 records · Page 2Linked to original sources
PubMed2004

Influence of different sources of information on attitude toward organ donation: a factor analysis.

OBJECTIVES: To determine media through which the population receives information on donation; to analyze the association between the sources of information and the psychosocial variables with respect to the opinion on donation; and to determine how each source of information influences this opinion. MATERIALS AND METHODS: A questionnaire on donation was administered to a random sample of 2000 persons stratified by age, gender, and geographical location, of whom 1143 respondents claimed to have no experience with donation and/or transplantation. A statistical analysis was done between the sources of information or the psychosocial variables or their co-variation to determine their specific impact on the population. RESULTS: The medium with the greatest impact on the population is television; the second factor is the press and radio; the third is magazines and talks with friends/family; the fourth is hoardings and posters, and campaigns about organ donation; and the last factor is information given by health professionals. In the factor analysis between sources of information and psychosocial variables, an association was observed between press, radio, and information given by health professionals and a higher education level; and between information provided by discussions in schools, by age, and a higher level of education. Sources of Information sources as that have a favorable effect on donation include discussions, (P = .0079), and information by health professionals (P < .0005) and by friends (P = .0132) and by family (P = .0044). CONCLUSIONS: Opinion on donation is more favorable among subjects who have received information on an individual basis and at specialized meetings. The only psychosocial variable associated with some sources of information is the level of education.

Adolescent↗
PubMed2004

Public attitude toward xenotransplantation: opinion survey.

BACKGROUND: Although xenotransplantation is still in an experimental phase, it is presented herein as a possible solution to the organ shortage. However, there are few data concerning how the general public would accept treatment with animal organs, especially after recent incidents of infections of animal origin, such as "avian influenza" or "SARS disease." The aim of this study was to determine the attitude of the general public toward xenotransplantation of organs. MATERIALS AND METHODS: Using an opinion survey, a study was performed on a random sample of 250 subjects in an urban setting. The questionnaire was administered by personnel from the regional transplant coordination center. Completion of the form was self-directed and anonymous for each respondent. The attitude toward donation of human and animal organs was evaluated by analyzing different psychosocial variables that may influence this attitude. A descriptive statistical study was performed using Student's t test and the chi-square test. RESULTS: Ninety-eight percent of respondents completed the survey (n=245). As for human donation, 60% are in favor of cadaveric donation with 21% are in favor of living donation, a rate that increases to 74% if it is for a living partner. As for animal donation, if the results were similar to those obtained with human organs, 74% (n=181) would accept an animal organ if they needed it, as opposed to 18% (n=45) who were undecided and 8% (n=19) against (P <.005). Analysis of variables that influence attitudes toward xenotransplantation showed that this attitude was more positive among those having had a previous experience with transplantation (P=.028) and those having a positive attitude toward cadaveric donation (P=.007). Factors traditionally related to cadaveric donation, such as manipulation of the body or pro-social activities, showed no influence. CONCLUSIONS: In the population studied, a positive attitude toward xenotransplantation was greater than toward cadaveric donation, assuming the results of these two types of transplants were comparable. Such an attitude is related to human donation, although it is not influenced by many traditional factors.

Animals↗
PubMed2003

Psychosocial profile in favor of organ donation.

INTRODUCTION: The lack of organ donation continues to be a major limiting factor in transplantation. Our aims are: (1) to define the psychosocial profile against organ donation, and (2) to determine the impact of a law on the procurement and transplantation of organs based on "presumed consent" in the population. MATERIALS AND METHODS: The population in this study (n = 2000) was randomly selected and stratified according to sex, age, and geographic localization. The attitude toward organ donation and transplantation was evaluated according to a questionnaire that probed psychosocial aspects of donation. Statistical comparisons were performed using the chi2 and logistic regression tests. RESULTS: The population attitude toward organ donation was favorable in 63% of subjects, unfavorable in 31%, and 6% did not respond. With regard to the law based on "presumed consent," only 24% of the population agreed with the law; 53% thought it was an abuse of authority. The population subgroup with a negative attitude to the law was characterized by: age over 40 years, low educational level, no previous experience with organ donation or transplant, no experience in prosocial activities, a refusal to accept cadaver manipulation or mutilation, and lack of knowledge of the brain-death concept. CONCLUSIONS: The psychosocial profile against donation is a person above 40 years with a low level of education who has never performed prosocial activities, did not have previous experience with organ donation or transplantation, displays no knowledge of the brain-death concept, and rejects cadaver manipulation. For these people a law based on "presumed consent" is considered an abuse of authority.

Adolescent↗
PubMed2001

Evaluation of microbial proteolysis in meat products by capillary electrophoresis.

AIMS: The available methods for evaluating proteolysis in meat products, particularly the contribution of micro-organisms, are expensive, time-consuming and require an unacceptable sample size. To minimize these problems, two capillary electrophoresis-based methods have been developed. METHODS AND RESULTS: Six Gram-positive, catalase-positive cocci, four moulds and three yeasts, isolated from dry-cured ham, were tested on sterile pork slices. Using the Capillary Gel Electrophoresis (CGE) method, changes in sarcoplasmic and myofibrillar proteins due to endogenous and microbial enzymes were detected. The Capillary Zone Electrophoresis (CZE) analysis allowed evaluation of bulk changes by micro-organisms in soluble nitrogen compounds. CONCLUSION: CGE analysis of myofibrillar proteins and CZE determination of soluble nitrogen compounds have proved to be valuable tools for evaluating proteolytic activity of endogenous and microbial origin. SIGNIFICANCE AND IMPACT OF THE STUDY: The CGE and CZE methods developed can be used for a rapid and sensitive analysis of proteolysis in meat products.

Animals↗
PubMed2001

Detection of insecticide resistance in Aedes aegypti (Diptera: Culicidae) from Cuba and Venezuela.

Four strains of Aedes aegypti (L.), one from Cuba and three from Venezuela, were bioassayed for susceptibility to eight insecticides, including the organophosphates, temephos, malathion, fenthion, pirimiphos methyl, and chlorpyrifos, and the pyrethroids, deltamethrin, lambda cyhalothrin and cypermethrin, S, S, S,-tributyl phosphorotrithioate and piperonyl butoxide were used as synergists to assess the involvement of esterases and monooxygenases in organophosphate resistance. Venezuelan strains had low levels of resistance to fenthion and malathion, and moderate to high resistance to temephos, pyrimphos methyl, and chlorpiriphos. All strains were susceptible to the pyrethroids, except the Cuban strain, which had moderate levels of resistance to cypermethrin. Organophosphate resistance in Ae. aegypti is a serious threat to control operations. Integrated strategies for Ae. aegypti control to prevent or delay pyrethroid resistance in Venezuela and Cuba are discussed.

Aedes↗
PubMed2001

Assessment of erythropoiesis activity during hemodialysis therapy by soluble transferrin receptor levels and ferrokinetic measurements.

The erythropoietic activity (EA) and degree of erythropoiesis attained by patients undergoing hemodialysis (HD) administered recombinant human erythropoietin (rHuEPO) were studied using ferrokinetic measurements and tests of soluble transferrin receptor (sTfR) levels, assessing which parameter is most useful for measurements in clinical practice. Plasma iron 59 ((59)Fe) clearance (half-life [T(1/2)] (59)Fe), plasma iron turnover (PIT), erythron transferrin uptake (ETU), and erythrocyte (59)Fe incorporation were determined in 23 patients before and at 4 months after administration of rHuEPO. sTfR levels, hematopoietic parameters, and iron metabolism parameters were measured periodically. T(1/2) (59)Fe was shortened (P: = 0.004), PIT and ETU were increased (P: = 0.032 and P: = 0.013, respectively), and the time taken by erythrocytes to incorporate 80% of the (59)Fe administered was reduced from 9.6 to 6.1 days. sTfR levels were increased by 15 days; this increase was significant (P: < 0.05) at 30 days, reaching a maximum of 3.22 mg/dL at day 45. A positive correlation was seen between sTfR levels and hemoglobin (Hb) (P: = 0.001), hematocrit (P: = 0.001), and reticulocytes (P: = 0.038) that was not found between ferrokinetic parameters and those evaluating efficient erythropoiesis (P: = 0.345 between ETU and Hb). In conclusion, EA is increased, shown by ETU and sTfR level. sTfR levels correlate with the parameters that evaluate efficient erythropoiesis, and their measurement does not involve the technical and/or ethical limitations of studies of ferrokinetics, making them the tool of choice in clinical practice for the evaluation of EA in patients undergoing HD administered rHuEPO.

Adult↗
PubMed2000

Rapid differentiation of Staphylococcus aureus from staphylococcal species by arbitrarily primed-polymerase chain reaction.

An arbitrarily primed-polymerase chain reaction (AP-PCR) method was optimized to differentiate Staphylococcus aureus from other staphylococcal species, using DNA from crude cell extract. From the different assays carried out, the best resolution of the band patterns was obtained when the reaction mixture contained 200 micromol l(-1) dNTPs, 200 ng primer, 1 U Taq DNA polymerase and 3 mmol l(-1) MgCl2 and the amplification conditions were: initial denaturation of 94 degrees C for 1 min, primer annealing of 30 degrees C for 1.5 min, DNA extension at 55 degrees C for 5 min and final extension at 55 degrees C for 5 min. The results of the characterization of the staphylococcal isolates by AP-PCR are in accordance with those of the biochemical identification by the API Staph System, time of analysis of the AP-PCR being only 6-7 h. Thus, this technique could be a useful method for microbial quality assurance.

Bacterial Typing Techniques↗
PubMed1998

[The selection of a strain of Culex quinquefasciatus resistant to lambdacyhalothrin and its spectrum of cross-resistance to other insecticides].

A field strain of Culex quinquefasciatus resistant to pyrethroid lambda-cyhalothrin insecticide was selected to be used as a reference strain in the laboratory for conducting studies of biochemistry and genetics of resistance, to evaluate the utility of this insecticide for the control of mosquitoes in Cuba, and to determine the cross resistance to organophosphate insecticides, pyrethroids and a carbamate. A high resistance to lambdacyhalothrin was obtained after 6 generations of selective pressure. Lowe or no cross resistance to other pyrethroids (deltamethrin and cypermethrin), to a carbamate (propoxur) and to the organophosphate insecticides (clorpirifos and methyl-pyrimifos) was observed. A high cross resistance to malathion (organophosphate) was detected.

Animals↗
PubMed1998

[Resistance in a strain of Culex quinquefasciatus coming from Medellín, Colombia].

The levels of susceptibility and/or resistance to 5 organophosphate insecticides (malathion, methyl-pyrimifos, clorpirifos, temephos and fenthion), 4 pyrethroids (cypermethrin, deltamethrin, permethrin and lambda-cyhalothrin), and a carbamate (propoxur) were determined in order to know the state of resistance in a strain of Culex quinquefasciatus from a locality of the city of Medellín, Colombia. Resistance to all organophosphate insecticides, though with relatively lower values for methyloirimifos and fenthion, was observed. No resistance to lambda-cyhalothrin and cypermethrin or to propoxur was found. These insecticides may be useful for the control of mosquitoes in Colombia. It was demonstrated by using the piperonil butoxide synergist that the oxidases of multiple function played an important role in the resistance to organophosphate insecticides and pyrethroids. The utilization of S.S.S. tributyl phosphotritiate revealed that the superproduction of unspecific esterases was a mechanism of resistance to organophosphate insecticides, except methyl-pirimifos and for perythroids, except lambda-cyhalothrin. This result should be taken into consideration for the strategies to be used to control Culex quinquefasciatus in Colombia. These two mechanism of resistance are not responsible for the resistance to propoxur. The electrophoretic analysis showed the presence of esterases B1, A6 and B6, which seem to have an important function in resistance.

Animals↗
PubMed1997

Detection of Clostridium botulinum types A, B, E and F in foods by PCR and DNA probe.

A PCR procedure was developed for the detection of Clostridium botulinum in foods. PCR products were detected in agarose gels and by Southern hybridization. The sensitivity of PCR was tested in broth cultures and in canned asparagus, dry cured ham and honey. The sensitivity of the method in broth was high (2.1-8.1 cfu ml-1) for types A and B, but rather low (10(4) cfu ml-1) for types E and F. However, after enrichment at 37 degrees C for 18 h, it was possible to detect Cl. botulinum types A, B, E and F in food samples at initial levels of about 1 cfu 10 g-1 of food. This PCR detection protocol provides a sensitive and relatively rapid technique for the routine detection of Cl. botulinum in foods.

Animals↗
PubMed1997

[Determination of insecticide resistance and its biochemical mechanisms in 2 strains of Culex quinquefasciatus from Santiago de Cuba].

It was analyzed the behavior of the resistance of 3 organophosphated insecticides (malathion, clorpirifos and methyl-pyrimifos), 3 pyrethroids (deltamethrin, lambda-cyhalothrin and cypermethrin), and 1 carbamate (propuxur) in populations of Culex quinquefasciatus from 2 municipalities of the province of Santiago de Cuba. The values of the resistance factor proved that there is resistance to malathion and clorpirifos. However, in spite of the existence of a high frequency of the mechanisms of elevated esterases and altered acetylcholinesterase no resistance to methylpymirifos, was observed which demonstrated that this insecticide is not affected by these mechanisms selected in our populations of Culex quinquefasciatus. There was resistence to deltamethrin, and lambda-cyhalothrin in Santiago de Cuba, whereas it was moderate to cypermethrin in Santiago and San Luis. Resistance to deltamethrin was also found in San Luis, but it was mild to lambda-cyhalothrin. The results obtained from the use of the synergists S,S,S tributyl phosphotritiade (DBF) and piperonyl butoxide (PB) indicated that the mechanisms of resistance of unspecific esterases and oxidases of multiple function are involved in the resistance to pyrethroids in both strains from Santiago de Cuba and San Luis. It was determined by the biochemical tests that there existed a high frequency of the mechanisms of esterases and altered acetylcholinesterase. The results of the polyacrylamide gel electrophoresis (PAGE) showed that esterase B1 appears more frequently associated with esterases A6 and B6. It was inferred that this association could be connected with the resistance to pyrethroids.

Acetylcholinesterase↗
PubMed1996

Yeast population during ripening of dry-cured Iberian ham.

The relationship between the superficial yeast population and the ripening conditions of Iberian dry cured hams has been studied for three different locations. Tentative identifications were carried out for 836 isolates. Candida zeylanoides was the dominating yeast in early stages, whereas more than 99% of isolates from the surface of matured hams were identified as Debaryomyces hansenii. A great diversity of strains of C. zeylanoides and D. hansenii was found. The characteristic pattern of isolates from the various locations and the selection of various strains of D. hansenii during ripening make the study of the yeasts useful for estimating the progress of maturation.

Animals↗
PubMed1996

Composition and toxigenic potential of the mould population on dry-cured Iberian ham.

The fungal population on dry-cured Iberian ham can be essential to the development of the product's unique characteristics, but health hazards due to mycotoxins may be significant. We examined the natural fungal population of Iberian hams during ripening at three different locations. Chloroform extracts from 59 selected isolates were tested for toxicity to brine shrimp larvae and VERO cells, for mutagenicity in the Ames test and for antimicrobial activity against Staphylococcus aureus. The diversity of moulds increased during ripening. Penicillium commune, Penicillium chrysogenum, Penicillium aurantiogriseum, Penicillium expansum and Penicillium echinulatum dominated most of the ripening time; however, the Eurotium species, particularly E. herbariorum and E. repens, increased in the final product. Using the above tests, most moulds were toxigenic. The toxigenic potential of the fungal population increased as the processing progressed. To minimize health hazards from uncontrolled fungal populations, we identified non toxigenic strains of Penicillium chrysogenum that could be used as starters in dry-cured hams.

Animals↗
PubMed1996

[3 combinations of esterases and their relation with the resistance to organophosphate, carbamate, and pyrethroid insecticides in Culex quinquefasciatus Say, 1823 (Diptera: Culicidae) in Cuba].

The possible relationship between different patterns of esterases and the resistance to various types of insecticides was analyzed by bioassays, biochemical tests, and electrophoresis carried out in a population of Culex quinquefasciatus from Camagüey and in three colonies obtained from it by family selection. The original population was heterogeneous and presented 8 combinations of esterases in polyacrylamide gel. A3A6B6, B1B6 and B1A6B6 were the most frequent of them and characterized each selected colony. Every studied colony, including the parental one, showed different levels of resistance to diverse insecticides. Only the resistance to propoxur showed less variation. In every colony it seems to exist a combination of resistance mechanisms; however, the differences found in tests with DEF synergized insecticides show that the different bands of zymograms may represent esterases contributing in a different way to resistance.

Animals↗
PubMed1996

[The evolution of resistance in a Culex quinquefasciatus strain starting from selection with the pyrethroid insecticide lambdacyhalothrin].

The resistance change to different insecticides in Culex quinquesfasciatus strain select at the laboratory with doses of pyrethroid lambdacyhalothrin that would cause a larva mortality of 90% were studied. It was attained an increase of the resistance to this insecticide of 144.5 times compared with the original level, and it was obtained a resistant strain (287x). There was an increase of the levels of resistance to methyl-pyrimifos (2.4 times), propoxur (6 times), DDT (5.2 times), clorpirifos (22 time), cypermethrin (67.5 times), and deltamethrin (20.2 times). The frequencies of the genes that codify for the elevated esterases enzymes and for the modified acetylcholinesterase reached their maximum value. Significant changes were observed in the phenotypes for esterases in the electrophoresis in polyacrylamide gels. It was detected synergism of DEF and PB with lambdacyhalothrin. Therefore, the elevated esterases and the esterases of multiple function may contribute to resistance.

Acetylcholinesterase↗
PubMed1995

[The association of resistance to organophosphate, carbamate and pyrethroid insecticides with the mechanisms of resistance observed in Culex quinquefasciatus strains from Ciudad de La Habana province].

The mechanisms of resistance in Culex quinquefasciatus from 6 municipalities of Havana City were studied in order to determine their genetic frequency. Increased esterases and altered acetylcholinesterase are still being the major resistance mechanisms in Havana City. The mechanisms of esterases is of high frequency, followed by altered acetylcholinestenase. Resistance to cholorpirifos was found for the first time in Culex quinquefasciatus, while resistance of malathion and carbamate propoxur is maintained, and deterioration to pyrethroid susceptibility is being detected. The synergistic effect of S.S.S. trubutyl phosphotritiade (DEF) and piperonil butoxide (PB) was analysed, and it was proven that esterases enzymes and multifunction oxidases are involved in the resistance to pyrethroids. By electrophoresis in polyerylamide gel, it was determined that the combination of esterases that seems to be associated with the resistance to perythroids is B1-A6-B6, which appeared with the greatest percentage. Valves of genetic frequency in the 6 municipalities were found to be high, for both esterase genes and acetylcholinesterase genes (Ache).

Animals↗
PubMed1994

[Determination of resistance mechanism in Culex quinquefasciatus Say 1823 and its operational implication in the correct use of insecticides for its control].

Resistance to organophosphorous insecticides such as malathion, chlorpyrihos, and pyrimiphos-methyl; pyrethroids such as deltametrine and lambda cialotrine; and the propoxur carbamate was determined in 4 strain of Culex quinquefasciatus of the Eastern, Central and Western parts of Cuba. The increase of esterase enzymes was the main mechanism involved in resistance, followed by altered acetylcholinesterase (AChe). Gene frequencies were high for esterases (1), and moderate for acetylcholinesterase (0.52) in the four strains under study, as an average. Bioassays showed resistance to malathion and propoxur. The use of DEF as esterase inhibitor showed that pyrimiphos-methyl was not affected by this mechanism of resistance, and chlorpyriphos was slightly affected. After 5 years of using pyrethroids such as deltametrine and lambda cialotrine, these are still useful agents for the control of C. quinquefasciatus; the alternate use of these and pyrimiphos-methyl or chlorpyriphos could prevent the development of resistance in a short or medium term.

Animals↗