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Biomedical subjects

M R Coelho

Publications and source records attributed to M R Coelho.

10 recordsLinked to original sources
PubMed2005

Effect of TBT on Ruditapes decussatus juveniles.

The effects of sublethal concentrations of tributyltin (TBT) on growth of juvenile clams Ruditapes decussatus were determined during exposure to TBT concentrations of 50, 100 and 250 ng l(-1) (as Sn) for a period up to two years. Length and weight of clams increased continuously in all treatments throughout the experimental period, and, overall, rates were not significantly influenced by TBT exposure, although final length and weight were inversely related to increasing TBT concentration. Juvenile R. decussatus therefore appear to be less sensitive to TBT than larval stages. Some juveniles exposed to TBT developed abnormal shell growth, laterally, changing the typical flattened shape of clams into a more "rounded" form. This characteristic was more visible in the anterior margins of valves than posteriorly, and mainly observed in clams exposed to TBT at 50 ng l(-1) (as Sn).

Animals↗
PubMed2002

Routes of TBT uptake in the clam Ruditapes decussatus. I. Water and sediments as vectors of TBT uptake.

This study assesses the relative importance of water and sediments as vectors of TBT uptake in the sediment-dwelling suspension feeder, Ruditapes decussatus. Accumulation of TBT was determined in R. decussatus exposed for 60 days to moderately high but environmentally realistic levels of TBT in water (100 ng Snl(-1)) and sediments (0.8 microg Sn g(-1) dw), separately or in combination, using constant-flow systems. The results indicate that this species accumulates TBT predominantly from water. Although some accumulation from sediments does occur, the processing of large amounts of water needed to sustain the filter-feeding habits of this species is a prime determinant of TBT uptake. The route of exposures reflected in tissue distributions of TBT in R. decussatus. However, gills are the most important site for accumulation of TBT from water, irrespective of whether contaminated sediments are present or not.

Animals↗
PubMed2002

Routes of TBT uptake in the clam Ruditapes decussatus. II. Food as vector of TBT uptake.

Marine bivalves are exposed to contaminants via the aqueous phase, sediments and food. Nevertheless, the relative importance of these phases as uptake vectors of contaminants in these marine organisms has not been well studied. Phytoplankton concentrate contaminants from seawater and given their position at the base of most marine food webs, these algal cells may play critical roles in the transfer of contaminants to higher trophic levels. This study assesses the relative importance of microalgae as a vector of tributylin (TBT) uptake in the infaunal, suspension-feeding bivalve Ruditapes decussatus. Accumulation of TBT via the algal diet was determined by experimental exposure of R. decussatus to 14C-TBT labelled phytoplankton Isochrisis galbana, for a period up to 60 days. The digestive tract of these clams initially accumulates TBT preferentially from food. After a few weeks of exposure, internal remobilization results in a more widespread partitioning of TBT amongst tissues.

Animals↗
PubMed1996

Spinal angiolipomas revisited: two case reports.

Approximately 60 cases of spinal angiolipomas have been described in the medical literature. Extradural tumours predominate. Lesions with a bony component, the infiltrating subgroup, were reported in 10 patients. Intradural angiolipomas were found three times. Several excellent review articles are available, but a systematic comparison of the characteristics of the two major varieties, infiltrating and non-infiltrating spinal extradural angiolipomas, has not so far been made. The authors operated on two patients with spinal angiolipomas and found one of them the infiltrating and the other the non-infiltrating type. Then, they proceeded to a review of all publish cases of infiltrating angiolipomas. With a knowledge of recently reported data on the subject the authors compared essential clinical features of both varieties of tumours. They share identical clinical characteristics. Differences found in age, sex or location were not statistically significant. Mode of onset and signs and symptoms present on admission were essentially similar. As could be anticipated, removal was more often complete in non-infiltrating tumours, but outcome was good or fair in more than 85% of cases in both groups. Involvement of bone by spinal angiolipomas does not imply a worsening in the prognosis.

Adult↗
PubMed1986

Immunopharmacological effects of Saccharomyces boulardii in healthy human volunteers.

Investigation of oral administration of Saccharomyces boulardii in healthy volunteers demonstrates several cellular and humoral changes in peripheral blood. Among its effects are the increase of erythrocytes, leucocytes, polymorphs, neutrophils, complement components C3, C5, C3d, serum anticomplementary activity and leucocyte chemokinesis, specially when autologous serum and antigen have been added to the culture medium and decrease of complement haemolytic activity (CH50, classic and alternative pathways). We have also demonstrated that in vitro S. boulardii was able to activate complement directly, to fix C3b to its surface and that its phagocytosis by mononuclear cells was complement-dependent. The overall changes in serum proteins suggested changes of acute phase proteins typical of an inflammatory process. Furthermore S. boulardii had no mitogenic response of lymphocyte populations. Our results demonstrated that S. boulardii activates the reticuloendothelial system and complement system and suggest that S. boulardii merits therapeutic trial in a variety of clinical situations.

Adult↗
PubMed1981

[Cutaneous angioleiomyomas. Review of 75 patients with 77 tumors].

Seventy seven angioleiomyomata from 75 patients, 19 males and 55 females, are reviewed. One patient had 2 lesions and another a local recurrence after surgical excision. Only 3 were less than 20 years old and most were beyond 30 (average age 47). Fifty four lesions were on the lower limbs, 4 on the head and legs), 9 on the upper limbs, 4 on the head and 1 on the trunk. The size of the lesions varied from a pepper grain to a pigeon egg but most were pea sized. The more significant symptom was pain, present in at least 58% of the lesions, and responsible for the diagnosis, often made, of neurofibroma, neuroma, glomus tumour and leiomyoma. Its intensity was variable and could be induced by mechanical or thermal stimuli or even arise spontaneously. Histologically the tumour was usually a deep dermal or hypodermal, well defined, ovoid or round shaped, compact nodule, composed of smooth muscle fibers often disposed around variously shaped vascular lumina. Clinical and histological similarities to glomus tumours as well as the occasional coexistence of both lesions point to a common origin from the myoarterial glomus or from a closely related arteriovenous anastomosis. The relevant features in our series are compared with those reported in the literature and their similarities and differences are discussed.

Adolescent↗
PubMed1981

[Simple epidermolysis bullosa. Anatomo-clinical considerations with respect to 7 cases].

Seven patients, belonging to seven different families, are reported. The clinical picture is dominated by the bullous lesions which appeared during the delivery or soon after birth; in one patient (case 4) the lesions first appeared after the first year of life. Besides the bullae there were erosions, crusts, residual macules but no millia cysts or scars. The nails were affected in several patients; the mucosae were affected in 2 patients. The histological aspects of the lesions are described; in all the cases it was possible to establish the position of the cleavage in regard to the functional membrane. The patients were treated with many different kinds of treatment which included topical and systemic corticotherapy; recently alpha-tocopherol (Roche) was assayed; none of the medicaments showed efficacy. The management of the patients relies on protective measures in order to avoid the formation of new lesions; gentle and time consuming nursing care is necessary to treat the patients. This must be explained to the parents of the patients as the care will rely on them. It is important to explain also the basic cutaneous defect that provokes the skin trouble and the necessity to avoid trauma and the possibility of the appearance of a new child with the defect in any subsequent pregnancy. The situation improves with age and this form of E.B. is compatible with a normal adult life.

Adolescent↗
PubMed1981

[Incontinentia pigmenti (Bloch-Sulzberger. Report of a patient with cerebral changes].

The clinical case refers to a three months-old female patient with incontinentia pigmenti. The cutaneous lesions, were the predominant features of the dermatosis; it consisted in vesicles, bullae, hyperkeratosis and pigmentation forming bizarre patterns. Associated with the dermatosis there were neurological abnormalities, which consisted in cerebral ulegiria. The child died during an episode of bronchiolitis. The necropsy showed; ulegiria cerebral, severe bronchopneumonia lobar and the cutaneous lesions.

Brain↗
PubMedDate not supplied

Biomarkers in Ruditapes decussatus: a potential bioindicator species.

The clam Ruditapes decussatus is distributed worldwide and due to its ecological and economical interest has been proposed as a bioindicator in areas where mussels are not available. The accumulation of several anthropogenic compounds in their tissues suggests that they possess mechanisms that allow them to cope with the toxic effects of these contaminants. Besides pollutant uptake, the use of biomarkers is pointed out in this paper since it is a promising approach to monitor the effect of these contaminants in the marine environment. Biomarkers complement the information of the direct chemical characterization of different types of contaminants. Therefore, the aim of this paper is to review the role of several biomarkers: (metallothioneins (MT), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidases (GPx) (total and selenium-dependent), lipid peroxidation (measured as MDA, one of the final products of lipid peroxidation), glutathione S-transferase (GST) and acetylcholinesterase (AChE), measured in different tissues of the clam R. decussatus, in laboratory conditions and under various environmental stresses, in two ecosystems (Ria Formosa lagoon- Portugal) and Bizerta lagoon (Tunisia) in a perspective of a multibiomarker approach to assess environmental changes. Experiment and field studies are in good agreement since MT levels, especially in the gills, the first target tissue of these contaminants, can be used as biomarker of exposure to Cd. GPx and MDA may also be determined in this respect. AChE activity is inhibited by pesticide and, to a less extent, by metal exposure in the gills and whole soft body of clams. However, the induction of GST isoforms experimentally demonstrated is not observed in the field because only global GST activity was determined. The whole set of results opens new research perspectives for the use of this species to assess the effect of mixtures of pollutants in the aquatic environment.

Acetylcholinesterase↗