Acta cientifica venezolana最新文献

{"title":"[DNA analysis for paternity testing and forensic identification].","authors":"L Pineda Bernal","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Non coding DNA of human genome contains an important part of tandem repetitive DNA which last years has been extensively applied to solve paternity disputes and individual identification cases. A class of this DNA are minisatellites and microsatellites loci. Such loci are highly polimorphics because they have a multiple of different alleles to make them ideals genetic markers for these purposes. This article is a review about these loci, methods of their analysis and practical aspects about their applications to determine biological paternity or individual identification in the forensic genetic field are considered.</p>","PeriodicalId":75378,"journal":{"name":"Acta cientifica venezolana","volume":"50 1","pages":"24-8"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21374569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Drugs, inhibitors and other stories. From cancer chemotherapy to nutritional toxicology].","authors":"A Carmona","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The designation as speaker of the XVIII Annual Conference \"Karl Gaede\", sponsored by the Asociación Venezolana de Bioquímica y Biología Molecular, provided me with the opportunity to revisit the path constructed in twenty five years of biochemical research. This path stretches from cancer chemotherapy to nutritional toxicology, following the elusive thread that interconnects the metabolic network buried in the ground of any biological process. This work summarizes experiences derived from the use of drugs, inhibitors and stimulators that act on specific enzymatic steps. As a metabolic artisan, I have used these tools to unveil the peculiarities and the inherent character that give continuity to the conductive thread across the whole biological universe.</p>","PeriodicalId":75378,"journal":{"name":"Acta cientifica venezolana","volume":"50 4","pages":"210-9"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21810146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Reaction time to dichotic visual stimulation and its relationship to cerebral hemispheric specialization].","authors":"M Coronel,&nbsp;D De Abreu,&nbsp;A Eblen-Zajjur","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>There is a renewed interest in the study of the cerebral hemispheric specialization given its physiological, physiopathological, clinical and educational relevancy. According to this, a stimulus is better processed in one of the cerebral hemispheres. The visual dichotic stimulation allows to present a stimulus selectively to one of the hemispheres, and this was used in the present study for the measurement of the reaction time (TR) and for the establishment of its correlation with an objective and validated measure of the cerebral hemispheric specialization. Ninety eight persons with an average age of 22.2 +/- 0.7 (X +/- EE) years were studied by means of the Oldfield protocol for the determination of the Cerebral Hemispheric Lateralization Index (IL). Additionally, the age, the sex and the date of last menstruation in the case of females, were registered. The dichotic stimulation and the determination of the visual TR was accomplished by computer with a time resolution of 100 microseconds. The stimulus consisted of the random presentation of a white square on a black background in a computer monitor, to which the subject had to respond by pressing a key with his best hand. The reaction time was registered 10 times in each visual field for a total of 20 records per eye. The IL of the sample was predominantly right (66.32 +/- 4.64), and significantly smaller in males than in females (p < 0.05). The TR to stimuli in the left visual field was significantly greater (p < 0.05) than in the right visual field for both eyes. When analyzing the global results of each cerebral hemisphere, a TR significantly smaller for the left hemisphere (304.33 +/- 4.1 ms) than for the right (312.35 +/- 4.5 ms, p < 0.05) was observed. These results suggest that the cerebral hemispheric specialization, expressed as a smaller response time, cannot alone be only the product of a better intrinsic hemispheric processing of the information, but also of the anatomical relationships of the proximity of the hemisphere that receives the stimulus and the center or area that will generate the response, as is the case of the motor center located in the left hemisphere in the immense majority of the right-handed subjects in the sample and in the general population.</p>","PeriodicalId":75378,"journal":{"name":"Acta cientifica venezolana","volume":"50 1","pages":"29-33"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21374570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Xanthan production by Xanthomonas campestris in a non-conventional culture medium].","authors":"R A Azuaje,&nbsp;J A Sánchez","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Among 3 varieties of Xanthomonas campestris, the variety ocumo (X. campestris pv. ocumo), showed the greatest capacity for producing xanthan. This bacteria grows appropriately and produces this polysaccharide in a wide diversity of carbohydrate sources. However, this strain does not produce xanthan when the carbohydrate comes from lignocellulosic materials. The glucose syrup FAVEPRO was the carbon source that showed the best yield (23 g/l) with the greatest viscosity (7000 cps) of xanthan. The optimum production conditions in 1 L erlenmeyer flasks, with a working volume of 0.2 L and in a 14 L (stirred tank type bioreactor) with a working volume of 10 L, were the following: total sugar 5%, urea 0.05%, di-potassium hydrogen phosphate 0.5%, pH 7.5, inoculum 10%, temperature 30 degrees C, agitation 250-1000 rpm and aereation 0.3-1.0 vvm. This strain of X. campestris pv. ocumo was able to produce xanthan (10 g/l) in a culture medium based on a previously treated agricultural waste, called soluble acid extract of cassava bark. The viscosity of this medium increased up to 1500 cps.</p>","PeriodicalId":75378,"journal":{"name":"Acta cientifica venezolana","volume":"50 4","pages":"201-9"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21810145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Domestic violence in Caracas: social and cultural predictors].","authors":"R Briceño-León,&nbsp;A Camardiel,&nbsp;O B Avila,&nbsp;E DeArmas","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The article gives an account of the results of a research intended to know violence reported by individual between couples and towards children and also to establish the importance of social (sex, income, education, civil status, work status, gun license, alcohol abuse, attraction to violent TV programs) and cultural (social norms about aggression between couples and children punishment, and capacity to express anger and handle conflicts in a non-violent ways) predictors in such behavior. The information is based on a survey applied to Caracas Metropolitan Area (CMA) inhabitants between 18 and 70 years of age (n = 1,297) selected by probabilistic, biphasic, and tetra-stage sampling, and at random following the Politz method. The instrument was a questionnaire with on scale answers Likert type. The information was treated with multi-varying statistical analysis, using the association technique between two variables by means of the Chi-square test, with conditional independence log-linear for three variables. The results suggest relatively low violence levels between couples and towards children. Regarding children, women tend to be more violent with them, most probably explained by factors relating income and unemployment. It was found that the bigger the accord with the norm to discipline children with physical violence, the bigger the frequency of violent behavior towards them. On the contrary, the bigger the conviction to be skilled in handling situations without violence, the lesser the frequency of violent behavior. Regarding violence between couples no association was found with the sex variable, but one can certainly talk about violent couples, which is related to the way of coupling, unemployment, and lack of formal education. From the norm point of view, a relationship between belief in the norms and violent behavior is observed, although these norms and attitudes are measured by the ability of the couple of control himself/herself and act in a non-violent way.</p>","PeriodicalId":75378,"journal":{"name":"Acta cientifica venezolana","volume":"50 2","pages":"132-43"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21431939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Predisposition to in vitro oxidation of LDL isolated from hypercholesterolemic patients. Interaction with arterial proteoglycans].","authors":"L Barón,&nbsp;F López","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>It is very well documented that cholesterol of the atherosclerotic plaques comes from LDL plasma particles and also a positive correlation between LDL plasma level and intensity of atherosclerotic lesions has been shown. Recent findings have revealed a direct relationship among arterial tissue atherogenic response and polyunsaturated fatty acids oxidation. The oxidized fatty acids within the low density lipoproteins makes these particles more atherogenic. In the present study the susceptibility of low density lipoprotein isolated from hypercholesterolemic patients to become oxidatively modified in vitro was investigated. The results show that the predisposition of hypercholesterolemic patients LDL to oxidation is fourfold increased, expressed in TBARS content (p < 0.0001) as compared to control LDL. Furthermore, the interactions of LDL with arterial proteoglycans apparently contribute to the accumulation of apo-B lipoproteins in atherogenesis. The hypercholesterolemic patients LDL shows higher values of proteoglycans-insolubilized LDL than LDL from controls.</p>","PeriodicalId":75378,"journal":{"name":"Acta cientifica venezolana","volume":"50 1","pages":"1-10"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21375328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chemical, physical and morphometric properties of Peruvian carrot (Arracacia xanthorrhiza B.) starch.","authors":"E E Pérez,&nbsp;R Borneo,&nbsp;C G Melito,&nbsp;J Tovar","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Starch was isolated from Peruvian carrot (PC)--or arracacha--(Arraccacia xanthorrhiza B.) roots. Its chemical, physical, physicochemical and granular structural properties were compared to those of commercial cassava starch. Scanning electron microscopy revealed a granular size for PC starch ranging between 4 and 26 microns in diameter, with spherical and truncated-egg shapes. PC and cassava starches were similar regarding gross chemical composition and basic physical characteristics but differed in pasting properties, with PC starch showing lower breakdown and consistency indices. The two starches also showed different water absorption and solubility patterns.</p>","PeriodicalId":75378,"journal":{"name":"Acta cientifica venezolana","volume":"50 4","pages":"240-4"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21810150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Graduate Program on Physiological Sciences of the School of Medicine of the Central University of Venezuela: XXV years of history].","authors":"A Ponte-Sucre,&nbsp;A T Torrealba,&nbsp;E González","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The Graduate Program of Physiological Sciences, the first Master's and Doctor degrees of the Faculty of Medicine from the Central University of Venezuela reached its XXV anniversary in 1998. These pages are devoted to describe and analyze the main subjects related to its growth and its pioneer role on the development of the 4th level studies in the Faculty of Medicine. Also, we discuss in these pages the plans for the future of this program.</p>","PeriodicalId":75378,"journal":{"name":"Acta cientifica venezolana","volume":"50 4","pages":"220-6"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21810147","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[High resolution ECG signals in Chagas patients: SEARCH project].","authors":"F Mora,&nbsp;P Gomis,&nbsp;G Passariello","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>This work presents contributions to the study of a public health problem known as Chagasic Myocarditis. The results of the efforts done in Venezuela to understand the evolution of this disease through a novel technique called High Resolution Electrocardiography (HRECG) are discussed. A review of this methodology is presented and also its potential as a tool to study Chagas disease and to diagnose its different myocardial manifestations is discussed in detail. Several research approaches are presented as well as the results obtained, new techniques for HRECG interpretation such as the analysis of signals from the P-R segment, the intra QRS potentials, and late potentials. This method contributes to early detection and follow up of Chagas myocarditis. The collection and the organization of a HRECG data base that served as the basis for SEARCH, which is a valuable resource for new research lines is also described.</p>","PeriodicalId":75378,"journal":{"name":"Acta cientifica venezolana","volume":"50 3","pages":"187-94"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21725208","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Chemical disturbance of the phytoplankton structure in an artificial pond (Guaicaipuru, Edo. Miranda, Venezuela)].","authors":"F González,&nbsp;E Zoppi de Roa","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>When an ecosystem is disturbed, it reverts to an early successional state, characterized by changes in community structure and function, that can be anticipated as response to stress. The purpose of this paper was to check the effect of a disturbance caused by application of chemical compound (Copper Sulfate, to 100 micrograms L-1 granular of 92%) on the phytoplankton community in a pond located in Guaicaipuro, Edo. Miranda (Venezuela), and compare the diversity and composition of the community before and after the chemical application. An additional purpose was, to test the Odum's hypothesis about the community response to chemical stress. The chemical compound was apply in different random points to assure homogeneous distribution in the water body. Only one application of the chemical was used 6 hours after the first sample was taken. Dissolved oxygen in surface and depth were measured. In order to estimate the diversity and composition of phytoplankton community, samples were taken in 5 random points of the pond, until a 2 liter sample was completed in an intermediary basis, during 30 days in the beginning of rainy season, between june and july of 1994. Oxygen showed a maximum value at surface of 9.3 mg O2/L and minimal value at depth (2.3 mg O2/L). Species richness varied between 4 and 18. Phytoplankton community varied between 7.1 x 10(4) and 7.8 x 10(6) cel/L, and diversity index between 0.12 and 1.39. Oxygen, species richness and phytoplankton minimal values were noticed at the fifth day after chemical application. Before chemical application, phytoplankton community was dominated by filamentous microalgae, especially Chlorophyta. After the fifth day, this group decreased in abundance and species number. On the seventh day small-size Cyanobacteria became dominant, particularly Chroococcoid forms. The community reverted to an early stage of ecological succession. Since the ninth day, community showed the following abundance sequence: Chrysophyta, Pyrrophyta, Bacillariophyta, and Euglenophyta, with an increased species richness. At the end of the study period, filamentous Chlorophyta species appeared. These results support Odum's hypothesis.</p>","PeriodicalId":75378,"journal":{"name":"Acta cientifica venezolana","volume":"50 4","pages":"195-200"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21810246","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}