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Biomedical subjects

P Varela

Publications and source records attributed to P Varela.

80 records · Page 5Linked to original sources
PubMed1986

[High protein diet in pregnancy. Effects on neonatal metabolism].

The effect of a high protein diet (20% casein + D,L-methionine) administered to Wistar rats during pregnancy on some aspects of cellular growth and RNA metabolism of progeny has been studied. Comparisons were made with well-nourished (10% casein + D,L-methionine) controls. Newborns individual weight, litter weight and number of newborns per litter were unmodified. However, neonate protein content dropped significantly when compared with controls. Both rate of DNA and number of nuclei were unchanged. Protein/DNA ratio (cellular size relative to protein) decreased, which might have led to an atrophy phenomenon, even if the newborn weight/number of nuclei ratio was not modified. Acid DNase activity rose, bringing about DNA breakdown. Total RNA content together with RNase activity fell in newborn from rats suffering high protein diet. Moreover, protein synthesis capacity (RNA/protein ratio) did not change. These results suggest that the administration of a high protein diet to pregnant rats lead to changes in newborn protein rate and nucleic acid turnover by modulating specific nuclease activity.

Animals↗
PubMed1986

[Additive effects of protein malnutrition and cortisol on plasma proteins and immunoglobulins of pregnant rats, and their offsprings].

This research work was carried out to study the effects of two immunosuppressive mechanisms: protein malnutrition and cortisol treatment on the feto-maternal unit. Therefore, plasma Ig G and Ig M levels were tested in pregnant rats submitted to a low protein diet (4%) and cortisol treatment (0.5 mg/100 g b.w.) during pregnancy and in their offspring. Nutritional status was evaluated by measuring ponderal parameters and plasma protein levels in rat dams and their neonates. Thus, a fall in ponderal parameters and in plasma protein levels was observed, both in rat dams suffering protein malnutrition as well as in their newborns. Cortisol treatment produced a decrease in the ponderal parameters of the control group, and an increase in plasma protein levels of the malnourished one, both in rat dams and in their neonates. Apparently, protein malnutrition might lead to a low functionality of B lymphocytes, caused by a decrease in Ig G and Ig M rates of malnourished rat dams. Ig M levels, however, increased in neonates as a consequence of possible concomitant infections. Cortisol treatment promoted humoral immune deficiency, since Ig G and Ig M levels decreased both in the control and in the malnourished pregnant rat groups. Nevertheless, cortisol administration seemed to increase susceptibility to infection in the newborns, especially in those born from malnourished rat dams.

Animals↗
PubMed1986

[Dietary protein level during pregnancy. Its influence on maternal-fetal exchange of substrates].

It is well known that the dietary protein level influences both the pregnancy process and development of the offspring. Therefore, a study was carried out to determine the effect that different protein percentages: 10%, 4% and 20% in diets administered to rats during pregnancy, had on food efficiency and on the substrates partition between rat dams and their neonates. Experimentation was thus carried out over a period of 21 days (pregnancy) and comparisons were made with well-nourished rats receiving 10% protein (controls) and between one and other group. Moreover, the effect on pregnancy was observed by comparing pregnant rats with non pregnant rats within each dietary situation. Food intake, weight parameters and food efficiency ratio were recorded in adult rats. Weight parameters were also evaluated in newborns. As results revealed, the highest the protein level in the diet, the highest the food efficiency ratio, both in the pregnant group and in the non pregnant group. Weight changes were determined in rat dams and their neonates, as a consequence of the different protein intakes. These also involved alterations in the substrates partition between the mothers and their offspring. Such findings might lead to the retention of substrates by the maternal tissues and, hence, to impairment of neonatal development.

Animal Nutritional Physiological Phenomena↗
PubMedDate not supplied

Exon-2 nucleotide sequences, polymorphism and haplotype distribution of a new HLA-DRB gene: HLA-DRB sigma.

Two new allelic exon-2 HLA-DRB sequences have been identified by using universal and also specific DRB primers. They may correspond to a previously unidentified DRB gene (DRB sigma) and define a new supratypic group ("DRw54") which includes DR1, DR"Br", DR2 and DRw10 bearing HLA haplotypes. This is probably the last HLA-DRB gene to be described in the standard DR haplotypes on the bases of the number of TaqI RFLPs obtained. Sequence comparison with their respective DP and DQ sequences shows that DRB sigma is unequivocally placed within the DRB family and also a constructed "neighbouring homology tree" indicates that DRB sigma gene is probably the eldest in the DRB family, thus the first to diverge from the ancestral DRB gene. An hypothetically deduced DRB sigma beta 1 protein domain was found to be quite different from the corresponding DRB1, DRB3, DRB4 and DRB5 products, since residues 40-55 would bear a longer alpha-helical conformation and would also exist a loss of both the extended conformation at residues 50-54 and the alpha-helix at residues 64-71. Thus, the putative DRB sigma protein would be remarkably different to other DRB ones. Also, a DRB sigma partial transcript (exon-2) has been obtained by PCR of cDNA by using specific DRB sigma oligonucleotides, but a specific Northern blot hybridization has not been achieved.

Alleles↗
PubMedDate not supplied

Immediate and delayed hypersensitivity to mite antigens in atopic dermatitis.

Atopic dermatitis (AD) is a common disorder and appears to be on the increase, especially among children. It was thought at first to be a manifestation of immediate hypersensitivity, but it is now known that delayed hypersensitivity also plays an important role. Sensitivity to mite antigens is found in 20% to 60% of patients when immediate hypersensitivity is evaluated by the detection of specific IgE antibodies and prick tests, and in 30% to 50% of patients when delayed hypersensitivity is studied by patch testing. A prospective randomized study was carried out in the pediatric dermatology clinic on a sample of 51 children under 15 years of age. A prevalence of immediate and delayed hypersensitivity to mites, like that described for other populations, was found. It was further found that there was a positive association, not described in the literature, between the younger age groups and delayed hypersensitivity to mite antigens, while the opposite was true for immediate hypersensitivity. We believe that patch tests with airborne allergens, specifically mites, should be part of the protocol for assessing children with AD, particularly in the younger age groups.

Age of Onset↗
PubMedDate not supplied

Two recent cases of tertiary syphilis.

Tertiary syphilis is now a rare disease in Europe, mainly as a result of occasional antibiotherapy for concomitant infections. However early syphilis is rising in USA and Germany, and it is necessary to maintain an high level of knowledge and suspicion to achieve a diagnosis in the tertiary stage of the disease. In this report two patients with benign tertiary syphilis are described. The first one is a 55-year-old female with erythemato-violaceous annular scaling plaques on the right buttock and scapula and on both thighs, which had a negative and then a low VDRL titer. The second case is a 33-year-old mentally handicapped female with erythematous plaques, with psoriasiform scaling in the trunk and well defined crusted ulcers on the face, which also had negative VDRL. Biopsy of the skin lesions revealed plasmocytic infiltrate with endothelial swelling without granulomas and with negative silver stains in both patients. The investigation for cardiovascular and neurological involvement was negative in both patients. Diagnosis of tertiary syphilis can be difficult as clinical pictures can be misleading, similar to other granulomatous diseases, and serological titers can be low or negative. We recall the necessity of ruling out neurological and cardiac involvement in this stage of syphilis. These cases are reported as a reminder of the possibility of syphilis, so that new cases are not misdiagnosed and mistreated as other diseases.

Adult↗
PubMedDate not supplied

[Chronic diseases in childhood: an approximate measurement of their impact].

As an approach to measurement of the importance of chronic diseases in childhood, type and frequency of diagnoses in children admitted to the pediatric wards of a general metropolitan hospital at Santiago, Chile, were reviewed and recorded along hospitalization and at the time of discharge from March 1 through June 30, 1989 (n: 426). Newborns were excluded. Main problems of the study were lacks of uniform national criteria to define chronic illness and of modern technology to certify diagnoses. Ninety five hospital discharged children (23.3%) were considered to have a definitive, confirmed chronic disease (CCD), other 51 (12%) were cases of possibly chronic disease (PCD) while the remainder were thought to be carriers of acute illness. Among 146 patients taken as CCD or PCD cases, 126 (87.7%) were considered to have single organic system diseases as defined by areas of medical interest or specialty; other 3 cases (8.9%) had two affected systems and 5 children (3.4%) had three or more involved systems. More frequently affected systems (in number of cases) and their corresponding proportions of CCD were as follows: neurologic (31 cases and 58.1% CCD), oncohematologic (28 cases and 96.4% CCD) and gastrointestinal (26 cases and 26.9% CCD). More extensive studies, covering other medical care providing settings are desirable and necessary to measure the magnitude and features of chronic disease entities in chilean childhood.

Age Factors↗