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Biomedical subjects

M Barbosa

Publications and source records attributed to M Barbosa.

27 records · Page 2Linked to original sources
PubMed1989

Breast-feeding and fertility in Macau.

That fact that only a small percentage of women in Macau breast-feed induced the need to investigate this attitude. In collaboration with the Maternal & Child Health Division of the W.H.O., Geneva, it was decided that a methodology which had already been applied in other places should be used to investigate the relation between breast-feeding and fertility. In this way, information was obtained about the situation, within a given period of time which permitted a description of the duration of amenorrhea due to breast-feeding, as well as the patterns of frequency and duration of breast-feeding.

Adolescent↗
PubMed1988

Quantitative keratinocyte assay detects two biological activities of human papillomavirus DNA and identifies viral types associated with cervical carcinoma.

Keratinocytes electroporated with human papillomavirus (HPV) DNA (HPV-6, 11, 16 and 18) exhibited an increased cellular proliferation which was quantitated as microcolony and macrocolony formation. However, only macrocolonies induced by HPV-16 or HPV-18 DNA (the two viral types most commonly found in human cervical carcinomas) gave rise to proliferating, poorly-stratified colonies when grown in the presence of serum and calcium. Hydrocortisone increased the frequency of these differentiation-resistant colonies, and studies showed that they were immortalized, contained one copy of viral DNA per cell, expressed three discrete species of viral RNA and synthesized the viral E7 protein. HPV-induced cellular proliferation and altered differentiation are therefore separable events and may represent the activity of different viral genes.

Biological Assay↗
PubMedDate not supplied

[Subarachnoid hemorrhage and computerized tomography cerebral angiography].

We present a review of 57 cases of nontraumatic subarachnoid hemorrhagesubmitted to CT angiography of the cerebral vessels. The purpose of our study was to estimate the value of CT angiography in the detection of intracranial aneurysms. These findings were compared with those from selective angiography. The results showed that CT angiography is a rapid, low-risk technique with a low level of invasiveness and high specificity and sensitivity in the detection of cerebral aneurysms, allowing the planning of endovascular intervention and surgical approach.

Adult↗
PubMedDate not supplied

[Neurobiology of addiction to drugs of abuse].

OBJECTIVE: In this review we study drug addiction from a neurobiological point of view, emphasizing the dopamine hypothesis. This is basic to explain how a genetic feature is related with an alteration of this neurotransmitter and can connect with environmental factors to develop the addiction problem. DEVELOPMENT: Toxic addiction is defined as the physical or psychophysiological dependence on a special chemical substance, whose suppression arouses deprivation symptoms in the person. The study of addiction to different drugs gives us a new approach for knowing the strengthening systems. Because even thought we do not know precisely the nervous mechanism of these substances that cause pleasure, we suppose that they are in the same place as rewarding and strengthening the behaviour mechanisms. In this way the dopamine hypothesis has been developed: in this hypothesis drug addiction is closely connected with a genetic upset of this neurotransmitter, so there is a defect in the reward system. This in turn stimulates the substance abuse that increases the brain s dopamine levels. CONCLUSION: Knowing the neurobiological mechanisms involved in addiction and its relation with dopamine and the reward system can help us understand that problem and aid the rational development of treatment

Animals↗