Biomedical subjects

J Relvas

Publications and source records attributed to J Relvas.

3 recordsLinked to original sources

PubMed2000

Plasma catecholamines during an ultrarapid heroin detoxification.

The adrenergic system has long been known to be activated in a situation of stress and thus during opiate withdrawal. A method for detoxification that decreases the stimulation of the sympathetic nervous system will prevent changes of catecholamine levels. Some of such methods have been developed. One of them uses direct transition from heroin to oral naltrexone after deep sedation with midazolam in conjunction with naloxone, droperidol, ondansetron, and clonidine treatment for 24 hours. Can such method prevent adrenergic changes? Moreover, 5-HT has been related to mood disorders. This study aims to determine plasma catecholamines and 5-HT before heroin withdrawal, during the day of the withdrawal, and at the ends of the first day, the first week, and the first 6 months. Forty-three patients with more than 6 years of drug abuse volunteered to seek help to detoxify. After clinical evaluation, blood samples were taken. Plasma catecholamines were isolated by standard alumina procedures and measured by high-performance liquid chromatography with electrochemical detection. Only for NE was there a significant decrease in the day of heroin withdrawal with deep sedation, followed the next day by an increase. During the following days, NE plasma concentrations returned slowly to basal levels. Epinephrine and dopamine plasma levels did not significantly change. Platelet 5-HT levels progressively decreased from the day before detoxification until the last period of observation. We also found that there were no abrupt changes in cardiovascular functions. In conclusion, our results suggest that this type of ultrarapid opiate detoxification prevents the dramatic activation of the autonomic nervous system.

Adult↗

PubMed1995

Dermal fibroblasts convert to a myogenic lineage in mdx mouse muscle.

Duchenne muscular dystrophy is a primary muscle disease that manifests itself in young boys as a result of a defect in a gene located on the X-chromosome. This gene codes for dystrophin, a normal muscle protein that is located beneath the sarcolemma of muscle fibres. Therapies to alleviate this disease have centred on implanting normal muscle precursor cells into dystrophic fibres to compensate for the lack of this gene and its product. To date, donor cells for implantation in such therapy have been of myogenic origin, derived from paternal biopsies. Success in human muscle, however, has been limited and may reflect immune rejection problems. To overcome this problem the patient's own myogenic cells, with the dystrophin gene inserted, could be used, but this could lead to other problems, since these cells are those that are functionally compromised by the disease. Here, we report the presence of high numbers of dystrophin-positive fibres after implanting dermal fibroblasts from normal mice into the muscle of the mdx mouse-the genetic homologue of Duchenne muscular dystrophy. Dystrophin-positive fibres were also abundant in mdx muscle following the implantation of cloned dermal fibroblasts from the normal mouse. Our results suggest the in vivo conversion of these non-myogenic cells to the myogenic pathway resulting in the formation of dystrophin-positive muscle fibres in the deficient host. The use of dermal fibroblasts may provide an alternative approach to the previously attempted myoblast transfer therapy, which in human trials has yielded disappointing results.

Animals↗

PubMedDate not supplied

[Depression].

The Portuguese Medical Association, through its Colleges of Specialistes, has decided to establish working groups to establish Therapeutic Guidelines in pathologies of great interest and current relevance in order to improve and rationalize health care. The group in charge of establishing the Therapeutic Recommendations in Depression, whose work I had the responsability and pleasure of coordinating during part of 1998 and 1999, is comprised of colleagues selected by the Portuguese Medical Association (Ordem dos Médicos). In the last few years, there has been rapidly increasing clinical and scientific interest in the study and treatment of depression throughout the life cycle, in different contexts and levels of medical practice. The rapid progress made in the neurosciences and psychopharmacology, new research in the field of psychotherapies and improved knowledge of relevant psychosocial aspects has not only broadened our knowledge of the aetiology and pathogenesis of depression, but also improved our criteria of diagnosis and classification. This has allowed the development of new therapeutic approaches and new drugs of proven efficacy. These Recommendations are aimed at systematizing and disseminating a consensus on interventions in depression, supported by evidence and the most recent scientific developments, in a way that will optimise therapeutic treatment. Due to some delay in the publication of these Recommendations (through no fault of the working group), and the rapid evolution of knowledge in this area, some of the contents may shortly need to be revised and updated. The writers and publishers of this document are fully aware of this and in accordance.

Clinical Protocols↗