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Biomedical subjects

R Parada

Publications and source records attributed to R Parada.

12 recordsLinked to original sources
PubMed2006

Gene expression profiling of hereditary exencephaly in chickens.

In this preliminary study, differentially expressed genes were investigated in cranial tissues from chickens with hereditary exencephaly using cDNA microarrays containing 1,152 genes and expressed sequence tags (ESTs). Genes showing twofold or greater differences at P < 0.05 between affected and normal cranial cells were considered to be candidates for hereditary exencephaly in chicken. Eighteen ESTs (11 known genes/homologues) were upregulated and 108 ESTs (51 known genes/homologues) were downregulated. The EST AL584231 (ROS006C9), orthologous to human MTHFD1, a known candidate gene for human neural tube defects (NTDs), was expressed at the same level both in normal and affected chicken cranial tissues. ESTs AL584253 (ROS006F7, thioredoxin reductase 1) and AL585511 (ROS024H9, thioredoxin), both involved in NTD pathogenic pathways in mice, were downregulated and had mean ratios of 0.41 and 0.04 for expression in affected vs. normal cells respectively. Expression differences of these two ESTs were confirmed by quantitative real-time polymerase chain reaction. These data indicate that ESTs AL584253 and AL585511 are candidates for hereditary exencephaly in chickens.

Animals↗
PubMed1999

Cytogenetic study of some tissues and age-related changes in cell proportions in a goat-sheep chimera.

Different percentages of cells with a female sheep or male goat karyotype were found in kidney (12.0% vs. 88.0%) and lung (42.6% vs. 57.4%) cell cultures from a 10-year-old chimera. Skin biopsies from patches with goat hair or sheep wool showed different, age-related goat-to-sheep fibroblast ratios. Karyotypic analysis of lymphocytes obtained from peripheral blood of the chimera at 6 and 10 yr of age showed no chimerism. Two weeks after birth, however, lymphocytes with both sheep (54,XX) and goat (60,XY) karyotypes were apparent in the blood of this chimera. Twenty percent of the blood cells examined at 2 wk had a caprine karyotype; this proportion declined with time, until it was totally eliminated at age 6.

Aging↗
PubMed1993

A cytogenetic study of cows from a highly industrial or an agricultural region.

An examination was made of the frequency of chromosomal aberrations and sister-chromatid exchange in the blood lymphocytes of cows from an industrial region (aluminium smelting plant, lignite quarries, briquette factory, electric plants, mechanical plants. The control group consisted of cows from an agricultural region. In cows from the industrial region a significantly higher level of chromosomal aberrations was observed than in cows from the agricultural region (5.82 +/- 0.46 vs. 2.11 +/- 0.31 per 100 cells). In older, 7-12-year-old cows from the industrial region a slightly higher level of chromosomal aberrations was observed, and a significantly higher level of gaps than in younger cows. The frequency of SCE in the blood lymphocytes of cows from the industrial region was also higher and reached 7.47 +/- 2.33 per cell, while in cows from the agricultural region it was only 6.38 +/- 1.88, but these differences were not significant statistically. However, significant differences were observed in the number of SCE between the age groups within the industrial region P < or = 0.001) in favour of the younger animals. The results obtained indicate that the industrial pollution emitted into the environment may have a genotoxic character. Thus cytogenetic examination of cattle may be a useful test for monitoring industrial pollution.

Age Factors↗
PubMed1987

Industrial pollution with copper and other heavy metals in a beef cattle ranch.

Experimental evidence of air borne heavy metal pollution as the cause of a disease of unknown etiology in beef cattle was obtained. Analysis of metals in natural grasses and leaves of tree defined Cu, Zn and Pb as the major pollutants, with Cd being a minor one. Emissions from a Cu smelter were traced as the main source of metallic pollution. No evidence of metal accumulation in the soil was found, mainly because of the short duration and intermittent pattern of pollution. A progressive intake of the several heavy metals contained in dusts deposited on the grasses was considered the cause of the sickness; this was associated with the grazing of cattle on contaminated grasses. The most severe cases were found in the most polluted pastures. Excepting Cd, the concentrations of the metals in the livers and kidneys of affected cattle were high. No overlapping of the respective ranges between test and control samples from both organs was found. Mean hepatic levels of Cu (925.7 mg/kg DM), Zn (491.2 mg/kg) and Pb (26.7 mg/kg) reflected the decreasing order of the concentrations of these elements in the polluted grasses. The main clinical and pathological features of this disease were discussed in light of the organic levels of the investigated metals. Disease could not be ascribed to a pure chronic toxicosis with any one of these.

Animals↗
PubMed1981

Zinc deficiency in molybdenum poisoned cattle.

Clinical signs ascribable to zinc deficiency were noted in a group of Friesian cows industrially poisoned with molybdenum. Zinc, copper, and molybdenum were determined in blood serum and black hair, and in the contaminated alfalfa pasture the group grazed on. Hematological parameters, and serum calcium and alkaline phosphatase activity, were also determined. Pooled samples of alfalfa from 2 uncontaminated pastures, and of blood, serum and black hair of clinically normal Friesian cattle grazing on these were used as controls. A mixed contamination of the polluted pasture with molybdenum and copper was found, both metals being inversely correlated with he distance to the polluting chimney. Zinc concentrations were normal and not significantly correlated with the distance to the chimney very high molybdenum was found in serum and hair of the poisoned animals; copper was normal in serum and hair. Low calcium and Alkaline phosphatase activity were found in serum, both variables being significantly correlated with serum zinc. Reduced red blood cell number, packed cell volumes and hemoglobin concentrations were also found, but no significant correlation of these parameters with any of the trace metals in serum or hair was found. Signs ascribed to zinc deficiency were consistent with the reduction of zinc in serum and hair and decreased alkaline phosphatase activity in serum. A zinc deficiency conditioned by a simultaneous increased intake of molybdenum and copper is proposed.

Air Pollutants↗
PubMedDate not supplied

Cytogenetic analysis of experimental interspecies goat-sheep chimera.

Chromosomal analysis was carried out on blood lymphocytes, skin fibroblasts, and germinal cells of an interspecies goat-sheep chimera. This chimera was produced by aggregation of blastomeres of goat and sheep embryos. A cell chimerism 54,XX/60,XY was found in blood lymphocytes and skin fibroblasts. At birth the percentage of lymphocytes with karyotype 54,XX (sheep) amounted to 80% and with karyotype 60,XY (goat) to 20%. With age the percentage of lymphocytes with chromosome complement 54,XX increased, so that at 18 months it was 94% sheep and 6% goat. At the same age, in skin fibroblasts the percentage of cells with goat karyotype reached 25%. Analysis of germinal cells showed in spermatogonia the presence of only karyotype 60,XY and in primary spermatocytes of 29 autosomal bivalents and the sex bivalent XY.

Aging↗