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Biomedical subjects

P H Saldanha

Publications and source records attributed to P H Saldanha.

At least 19 recordsLinked to original sources
PubMed2001

Frequency of oral mucosa micronuclei in gas station operators after introducing methanol.

Methanol has been proposed in different countries as an alternative automotive fuel to be used as an additive to, or replacement for, gasoline or ethanol. Utilization of methanol is increasing exposure to low levels of methanol vapors in the environment and more specifically in occupational settings such as gas stations. Pump operators are exposed to relatively high levels of fuel vapors, the consequences of which have not been fully examined. In this study, the micronucleus assay in squamous oral cells was performed on pump operators of 28 gas stations in three different periods in the city of São Paulo, Brazil. The frequency of micronuclei (MN) was evaluated before and 1 year after a mixed fuel called MEG, which contains 33% methanol, 60% ethanol and 7% gasoline, was introduced. The third evaluation, 3 years later, represents a period where the number of cars using alcohol fuel had decreased drastically and the pump operator exposure to MEG became very low. The frequency of MN observed in 76 employees in 1992 (mean = 3.62 +/- 0.39) was significantly increased (P < 0.001) as compared with 76 operators exposed in 1989 (mean = 1.41 +/- 0.26) and 129 exposed in 1995 (mean = 1.20 +/- 0.15). These differences were also significant when compared with control groups not exposed professionally to motor fuel. These findings could indicate a mutagenic hazard of the MEG occurring in those with occupational exposure.

Adult↗
PubMed1997

Chromosomal aberrations in peripheral lymphocytes of abstinent alcoholics.

The frequency of structural and/or numerical chromosomal aberrations in human metaphasic cells of lymphocyte cultures from abstinent alcoholics who were abstinent for 1 month up to 32 years was compared with those from controls not selected for alcohol consumption. Cytogenetic analyses revealed a significant increase of the frequencies of cells with structural aberrations in the abstinent alcoholics (7.1%), compared with controls (2.4%). The frequency of numerical aberrations showed a significant regression on ages in abstinent alcoholics and controls. These results suggest specific action of chronic alcohol consumption impairing biological repair with aging. The increased frequency of chromosome-type aberrations associated with alcohol consumption, even after long withdrawal, could be due to an action of ethanol or its metabolites on primordial leukopoietic cells.

Adult↗
PubMed1991

[Macrosomia, macrocrania and motor disorders in childhood, Sotos syndrome (McKusick 11755): report of 7 cases and review of clinical aspects of 198 reported cases].

Children with Sotos syndrome have growth acceleration, macrocephaly, acromegaloid features and delay in neuropsychomotor development during infancy. Syndrome delineation and differential diagnosis are based on evaluation of phenotypic characteristics and evolutive history of the patients. Seven patients with this syndrome are reported, and the relative occurrence of the phenotypic characteristics present in 198 reported cases are reviewed. Motor difficulties present in those patients during early infancy are responsible for the poor performance on IQ tests. Oriented stimulation should be encouraged in order to help the affected children to overcome their initial difficulties and to achieve normal scholarity and life performance.

Adult↗
PubMed1987

A clinico-genetic investigation of Leydig cell hypoplasia.

We report on a kindred including a patient (46,XY) with typical manifestations of Leydig cell hypoplasia who was born to parents who were first cousins. A sister had secondary amenorrhea possibly due to primary ovarian dysfunction. Analysis of six pedigrees fits to a male-limited autosomal recessive pattern of inheritance; its implication for the mutational dynamics in the populations is evaluated.

Adrenal Glands↗
PubMed1981

Familial dwarfism with high IR-GH: report of two affected sibs with genetic and epidemiologic considerations.

Two sibs with high serum IR-GH dwarfism, born to first-cousin parents are described. Genetic analysis based upon 25 reported informative kindreds indicates that the condition has an autosomal recessive pattern of inheritance. Population evaluation and epidemiology of the affected subjects suggest that mutation rates of the gene determining the disease in non-Jewish populations could be as rare as 3.2 x 10(-5). However, its prevalence must be exceptionally high among endogamous Oriental Jewish groups derived from a common gene pool in historical times.

Adolescent↗
PubMed1981

The karyotype of Cacajao melanocephalus (Platyrrhini, Primates).

Chromosome studies were performed in a male representative of Cacajao melanocephalus. The diploid number was 45: the chromosome complement consisting of 12 pairs of acrocentric autosomes, 9 pairs of biarmed autosomes and 1 heteromorphic pair composed of one subtelocentric and one acrocentric chromosome. The X chromosome was submetacentric and the Y chromosome was apparently translocated to an acrocentric autosome. G-banding patterns were studied and the results compared to karyotypes previously described for Cacajao rubicundus and Cacajao calvus.

Animals↗
PubMed1979

Dyggve-Melchior-Clausen syndrome: genetic studies and report of affected sibs.

We report a brother and sister with Dyggye-Melchior-Clausen dysplasia with mental retardation (MR) but as yet without spinal cord injury due to cervical spine abnormality. Mucopolysaccharide metabolism was studied in several ways and was found to be normal. Segregation analysis and study of consanguinity data confirm that both forms of the syndrome--that with MR, and that without MR (Smith-McCort dysplasia) are rare autosomal recessives. Spinal cord injury and early death is a danger in both.

Bone Diseases, Developmental↗
PubMed1976

Activity of glucose-6-phosphate dehydrogenase among Indians living in a malarial region of Mato Grosso and its implication to the Indian-mixed populations in Brazil.

Erythrocyte glucose-6-phosphate dehydrogenase (G-6-PD) activity and electrophoresis were investigated among 154 Indians living in a region hyperendemic for malaria at Alto Xingu, Mato Grosso, Brazil. No enzyme-deficient individual was found, and all subjects belonged to enzyme type B. No statistical difference in G-6-PD levels was found between tribes and sexes. The average of G-6-PD activity of the Indians was significantly higher than the normal mean values found by the same technique in Caucasians, Negroes and Japanese of Säo Paulo, Brazil. The high rates of G-6-PD activity of the Indians are not correlated to an increased reticulocytosis by hypochromic anaemia and appear to be typical of Indian or Indian-mixed populations. Resistance to malaria in those populations should not involve erythrocyte G-6-PD deficiency. It is suggested that the apparent association between G-6-PD deficiency and resistance to malaria found in other populations could be a statistical accident determined by the racial correlation between the incidence of G-6-PD deficiency and sickle-cell or thalassaemic haemoglobins among Negro and Mediterranean populations.

ABO Blood-Group System↗
PubMed1976

[Value of cytogenetic study in transsexualism].

By reviewing the syndromic manifestation, transsexualism in characterized as a psychiatric entity, apart from homossexualism and transvestism. The two main feasible etiologic causes of transsexualism are discussed: the psychoanalytical hypothesis based upon psycossexual regression with imprinting of maternal figure and the neuroendocrine model which assumes alterations of the gender role identity centers in the hypothalamus. On the grounds of the latter explanation and after the scheme that seems to occure in the Morris syndrome whose cells (XY) do not respond to the masculinizing effect of plasma testosterone, it is proposed that transsexuals should possess detectable or cryptic sex-chromosome mosaicism affecting hypothalamic centers of gender role identity which do not respond to the androgenic secretion produced by primitive gonad. This possibliity explains the excessive prevalence of the syndrome among men, its typical features in the male as well as its sporadic occurrence. Cytogenetic investigation reveals that the frequency (32%) of sex-chromosome mosaicism among 25 transsexuals and 40 normal control people, both groups presenting the proportion of the mosaicism practically null. The karyotypic criterion as a valuable aid in the syndrome diagnosis is considered.

Cytogenetics↗