Biomedical subjects
Publications and source records attributed to M D Garcia.
The antimicrobial activity of some lichens from south Spain has been studied and some of plant constituents were identified. Activity against some Gram (+) bacteria has been observed in lichens containing usnic acid.
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Several reports have demonstrated that bovine chromosome 26 (BTA26) harbours significant or suggestive quantitative trait loci (QTL) for milk production and composition traits in dairy cattle. Our previous study showed that a C/T substitution in the bovine TCF7L2 gene on BTA26 was significantly linked to QTL for protein yield (PY) in a Canadian dairy cattle population. Actually, this polymorphism was one of the markers derived from a genome-wide screening of QTL for milk PY using an amplified fragment length polymorphism technique combined with a DNA pooling strategy. In the present study, 990 Holstein bulls with complete genotype and phenotype data from 14 sire families were analysed to confirm, if the QTL effects exist in other populations. Statistical analysis revealed that this marker was significantly associated with PY, protein percentage, milk yield and fat yield (FY) (p < 0.001) in the US Holstein population. These results indicate that this QTL region has a pleiotrophic effecton different milk traits and is portable in different populations.
Understanding metabolic differences between breeds of cattle is important when selecting for production in semiarid environments. Spring-calving multiparous Angus and Brahman cows (n = 8/breed) grazing in the Chihuahuan Desert were used to evaluate metabolic hormone status in February (i.e., 3rd trimester of pregnancy), May (i.e., early lactation), and September (i.e., late lactation) 2000. Crude protein in ruminal digesta collected from grazing companion ruminally cannulated cows during these months was 5.6, 6.0, and 10.3%, respectively. Angus cows were heavier (P < 0.01) than Brahman cows across months. Body condition scores among breed groups were 4.4, 3.6, and 4.6 in February, May, and September with Brahman cows tending (P < 0.10) to have greater body condition than Angus cows in May. Brahman cows tended to have greater fecal output per 100 kg BW than Angus cows in February (0.9 > 0.7 +/- 0.1, P < 0.10). Brahman cows had greater serum concentrations of leptin than Angus cows in September (1.8 > 0.70 +/- 0.1 ng/mL; P < 0.05), and serum concentrations of insulin were greater (P < 0.01) in Brahman than Angus cows throughout the study. Brahman cows also had greater (P < 0.01) serum concentrations of glucose during February and May than Angus cows. Serum concentrations of triiodothyronine were greatest (P < 0.01) during September and lowest during February and May in both breed groups and were greater (P < 0.01) in Brahman than in Angus cows in February, May, and September. Pregnancy rate and 205-d adjusted weaning weights were similar (P > or = 0.46) among breed groups. Results suggest that Brahman and Angus cows are sensitive to the seasonal dynamics of forage quality in the Chihuahuan Desert. Brahman cattle appear to have greater concentrations of metabolic hormones and metabolites than Angus cows in this environment, but Angus cows experience greater fluctuations in BW.
The cytostatic activities of Agave intermixta L. (Agavaceae) and Cissus sicyoides L. (Vitaceae) have been determined. In the antimitotic assay, Agave intermixta L. showed complete inhibition of cell division at 24 h of treatment. Both species showed a moderate cytostatic activity against HEp-2 cells, Cissus sicyoides L. being the most active species.
In 1992 some samples of mosses, lichens and soils were collected from Botany Bay, Southern Victoria Land (77 degrees 01' S 162 degrees 32' E) and, as a result of a routine screening programme some yeasts were isolated. One of them, designated as strain G5, showed marked differences when compared to other antarctic yeasts. According to morphological and physiological characteristics, we were able to identify the strain G5 as a yeast belonging to the genus Cryptococcus. Some characteristics of this genus are the growth response to myo-inositol, celobiose, raffinose and D-glucuronate, no-fermentation, the absence of mycelium and pseudomycelium, asexual reproduction, Diazolium blue B test (DBB) and urea hydrolisis positive and the growth without vitamines. This strain (G5) formed cream colonies of slimy appearance with cells of 3 x 2 microns in size, that grew between 4 degrees C and 20 degrees C. The G + C content of strain G5 was 50.3 mol%. The molecular characterization by whole-cell proteins and RFLP analysis of the 5.8S rRNA gene and the two ribosomal internal transcribed spacers (5.85-ITS region), revealed that this strain was different from other antarctic species of this genus. The phylogenetic tree deduced from the 5.8S rRNA gene sequence showed the strain G5 as a member of the genus Cryptococcus, clearly separated from other basidiomycetous yeasts. On the basis of the physiological, genotypical and phylogenetical data, the new isolate G5 was described as Cryptococcus victoriae, sp. nov., with the type strain G5 (= CECT 11114).
Oleuropein, tyrosol, squalene and the fraction of sterols and triterpenoid dialcohols from the unsaponifiable fraction obtained from virgin olive oil have been tested for possible cytostatic activity against McCoy cells, using 6-mercaptopurine as a positive control. The samples of sterols and triterpenic dialcohols showed a strong activity.
The present study was designed to examine the incorporation of phytosterols (PS) in membranes and tissues of rats fed a diet containing 2% PS in the presence of 0.2% cholic acid for 22 days. The control diet contained 12 mg PS/100 g compared with 2,012 mg/100 g. Liver, kidney, testis, and prostate microsomes, plasma, and epididymal fat pads were examined for sterols. Fatty acid composition and phospholipid pattern were also examined in some tissues. The PS diet resulted in a fivefold increase in plasma PS compared with controls. PS was found to accumulate in adipose tissue and liver microsomes in rats fed the PS-supplemented diet. There was no effect of PS incorporation on microsomal cholesterol content, except in the testes, in which dietary PS reduced cholesterol content by 25%. Dietary PS increased 20:4n-6 and 22:5n-3 fatty acids in membranes of the liver, testis, and prostate but decreased 16:1 in liver microsomes. PS incorporation had no effect on the phospholipid pattern of the liver and testis.
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Sixty-one children with insulin-dependent diabetes mellitus and twenty-three healthy subjects were investigated. The patients with diabetes mellitus aged 4 to 20 years (13.4 +/- 4.0) had had diabetes for 1 to 16 years (6.4 +/- 3.5). There were no cardiovascular risk factor other than diabetes. Patients received no medication other than insulin. The following echocardiographic and Doppler parameters of the left ventricle were analyzed in both groups: systolic and diastolic dimensions, systolic time intervals, fractional shortening, mean velocity of circumferential fiber shortening, percent relaxation of the left ventricular posterior wall at 50% of diastole, peak velocity of early (E) and late atrial (A) mitral flow. E/A ratio, deceleration of the E-wave, and the isovolumetric relaxation time. None of the parameters were significantly different between the groups. There was no relation observed between duration of diabetes and any of the parameters analyzed. It is concluded that there is not echocardiographic data to support the concept of diabetic cardiomyopathy in adolescents with type I (insulin-dependent) diabetes mellitus.
The Bio-Bio river, running through one of the most important hydrographic basins in Chile, presents concentrations of some chemical agents exceeding the accepted values for continental aquatic environments. The area near to the mouth of the river is highly industrialized and the industrial effluents are discharge directly into the river, most of them without any previous treatment. This river provides the principal source of drinking water for a population of more than one million inhabitants in the region. To evaluate the genotoxic effects of liquid effluents from a cellulose industry and the surface waters of the Bio-Bio river obtained near to the river mouth in the proximity of Concepción city, a short-term bio-assay with cultured Chinese hamster ovary (CHO) cells was used. The frequency of cells with chromosome aberrations in metaphase, anaphase and telophase was determined at different concentrations of the liquid samples. The results show a significant increase in chromosomal damage. The frequency of chromosomal aberrations observed both in metaphase and ana-telophase is dose-related to the concentrations of liquid samples tested. The superficial water shows a significant genotoxic effect. The scope of these results is discussed and compared to results obtained in other biological models.
Two asymptomatic children with an atypical continuous murmur and a clinical diagnosis of coronary artery fistula are reported. Cross-sectional and Doppler echocardiography led to the diagnosis of a right coronary artery-right ventricule fistula in both cases, which was confirmed by coronary angiography. Surgical closure of the fistula was realized without complications.
A colony of Amblyomma parvum was started with engorged females collected from cattle in the Province of Salta (25 degrees 01' S, 63 degrees 56' W), Argentina. The progeny of those ticks were fed on rabbits and the non-parasitic stages maintained at 27 +/- 1 degrees C, 83-86% RH in darkness. The life cycle (prefeeding period not evaluated) had a mean duration of 99.6 days. The mean time (days) for the different phases of the cycle were as follows: feeding period of females, 8.0; pre-oviposition period, 5.7; oviposition period, 17.5; minimum incubation period of the eggs, 31.8; feeding period of larvae, 3.2; premoult period to nymphs, 10.9; feeding period of nymphs, 4.7; premoult period to adults, 17.8. The oviposition pattern was typical of an ixodid tick, including a linear relationship between weights of engorged females and the number of eggs laid (r = 0.8659). The males increased 18% in weight after feeding on hosts (P less than 0.01). The mean recovery rates of larvae, nymphs and females were 28.2%, 95.3% and 90.7%, respectively. The nymphs moulting to females were heavier (6.8 +/- 0.69 mg) than those moulting to males (3.2 +/- 0.29 mg) (P less than 0.01). A comparison of biological values of A. parvum with American and non-American Amblyomma species is presented.
Antimicrobial activity in some lichens from south Spain has been studied. Some lichenical substances are also identified. A very hight activity has been observed in lichens with usnic acid.
A case of double outlet left ventricle with pulmonary atresia is reported. The hypoplasia of the left ventricule produced by the almost total absence of its trabecular zone has not been previously reported.
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Antibacterial activity of some lichens from south Spain has been studied. High activity against Gram+ bacteria has been observed, although Parmelia caperata, Evernia prunastri and Usnea sp. are also active against Gram- bacteria.
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