Biomedical subjects

M L Carvalho

Publications and source records attributed to M L Carvalho.

At least 19 recordsLinked to original sources

PubMed2006

Assessment of metal availability to vegetation (Betula pendula) in Pb-Zn ore concentrate residues with different features.

In this work, characterisation of several ore concentrate remains from an abandoned Pb-Zn mining factory was performed determining chemical and physical properties such as pH, organic carbon content, particle size distribution, total heavy metal content (Pb, Zn, Cu, As and Cd) as well as mineralogical composition which showed, in most cases, the oxidization of the parent ore material (mostly galena: PbS and sphalerite: ZnS) to more mobile fractions as anglesite (PbSO(4)) and goslarite (ZnSO(4)). Moreover, two operational defined extraction procedures commonly used in soil and sediment studies (first and second steps of BCR procedure and DTPA extraction protocol) were applied in the different mining wastes in order to study Pb and Zn mobility and likely bioavailability to Betula pendula growing on the same mining spoils, which presents lead and zinc contents in leaves over ten times background values.

Arsenic↗

PubMed2005

Assessment of the essential element and heavy metal content of edible fish muscle.

The aim of this work was to determine the concentrations of some essential and toxic elements in the muscle of ten species of commercial fish consumed in Portugal. We combined two different techniques for determination of the elements--energy-dispersive X-ray fluorescence (EDXRF) was used to quantify K, Ca, Fe, Zn, Se, Rb, and Sr and flame atomic-absorption spectrometry for analysis of Cr, Ni, Cu, Cd, Hg, and Pb. The latter technique was used because of its higher sensitivity, because these elements were not detected by EDXRF. The results obtained show a similar pattern for the trace elements. K and Ca are present at the highest concentrations in all the samples studied, from 0.6-1.3% and from 0.04-0.08%, respectively, followed by Zn, Fe, Sr, Se, and Rb. Sr is present at higher concentrations than Rb in all the species studied except meagre. Concentrations of the elements in octopus do not follow this pattern--Fe is present at a higher concentration than Zn. Low concentrations of Cr (0.66-1.5 microg g(-1)), Ni (0.11-0.24 microg g(-1)), Cd (0.01-0.08 microg g(-1)), Hg (0.49-2.74 microg g(-1)), and Pb (0.02-0.06 microg g(-1)) were observed in all the samples analysed. The concentration of Hg was highest in Helicolenus dactylopterus--5.4 microg g(-1) in one sample.

Animals↗

PubMed2005

Study of heavy metals in wild edible mushrooms under different pollution conditions by X-ray fluorescence spectrometry.

In this work we studied and compared the metal uptake in edible mushrooms (Lepiota procera, Boletus badius, Boletus edulis, Tricholoma equestry, Lactarius deliciosus, Cantarelus tubalformis and Cantarelus edulis), relative to sampling sites submitted to different pollution conditions: car traffic, soil pollution due to pesticides and fertilizers used in old vineyards, and incineration of hospital waste. Soil was also collected in some places, and its content was correlated to the corresponding one in some mushrooms species. All samples, without any chemical treatment, were analyzed by an X-ray fluorescence set-up. This technique is based on a monochromatic X-ray beam ionizing the atoms of the sample. Following this ionization, the emitted radiation is characteristic of the element, allowing its identification and quantification. Vineyards are normally submitted to very high amounts of sulfating, containing high copper concentrations. This metal is accumulated on the soil, and can be up-taken by vegetation. Very high levels of Fe and Cu were found in Lepiota procera species in old vineyards. Zinc was found to be always higher than Cu by factors ranging from 1.5 to 8 in clean wood taken as a reference for the whole analyzed species, while in old vineyards the ratio Zn/Cu reach 0.25 for Lepiota procera. This is correlated to the soil content for both elements. In addition, pollution induced by car traffic was checked in some samples, collected in the proximity of highways. Pb was the main contaminant in these areas, and presenting values 10 times higher than the corresponding ones in sites not submitted to pollution, for some species. Mushrooms contamination due to incineration of hospital waste was also studied, but we did not observe any contamination involving heavy metals in the several analyzed species around these areas. This is in agreement with what was expected, taking into account that hospital waste is mostly organic and, in principle, no heavy metals would be observed.

Agaricales↗

PubMed2003

Trace elements determination by energy dispersive X-ray fluorescence (EDXRF) in human placenta and membrane: a comparative study.

This work is an application of energy dispersive X-ray fluorescence (EDXRF) as an analytical technique for trace elemental determination in human membrane and placenta and elemental concentrations correlations in both tissues. Whole samples were collected during the delivery from healthy mothers and full-term pregnancies. The age of the mother was between 25 and 40 years old, and the weight of the infants ranged from 2.56 to 4.05 kg. Samples were lyophilised and analysed without any chemical treatment. No significant differences in elemental content of placenta and membrane samples were observed except for Ca. Very low levels of Se, As and Pb were observed in all the analysed samples. Zn, considered as one of the key elements in newborn health, was not significantly different in the analysed samples, all of which originated from healthy mothers and healthy babies. The obtained values agree with the literature except for Ca, which is much higher in the studied samples.

Adult↗

PubMed2002

Heavy metals in soft tissues of Tursiops truncatus and Delphinus delphis from west Atlantic Ocean by X-ray spectrometry.

In this work, the concentration of heavy metals in muscle, liver, fat tissue and skin is studied in 15 Delphinus delphis and two Tursiops truncatus dolphins, stranded along the Portuguese coast of the Atlantic Ocean. Sample collection was performed post-mortem and the tissues were kept frozen until analysed. Sample preparation included lyophilising and grounding in a Teflon mill to avoid contamination by metals. The obtained powder was prepared as pellets for each sample and analysed directly by X-ray fluorescence spectrometry. The concentrations of K, Ca, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Br, Rb, Sr, Hg and Pb were obtained. Significant differences between the muscle, the skin and the fat tissues were detected. Cobalt concentrations were similar in liver, skin and muscle. The levels of Ni, Rb and Sr are at the level of the detection limit and whenever measurable are rather constant in all the analysed tissues. The results show that the highest concentrations of Mn, Cu and Hg are always in liver tissues. Zinc and Se concentrations are higher in skin and Pb is present in very low concentrations in all the analysed tissues except in skin; Fe and As are enhanced in muscle and liver. In general, the two studied species did not seem to differ significantly in their heavy metals concentration in a given tissue.

Adipose Tissue↗

PubMed2002

Effects of cadmium on cation concentrations in sycamore cells (Acer pseudoplatanus L.): application of EDXRF.

Knowledge of the element content of biological systems is important in enabling understanding of uptake mechanisms and physiological response to stress conditions. In this work concentrations of mineral elements in sycamore (Acer pseudoplatanus L.) cells grown in the presence of cadmium have been analysed and compared with concentrations in control cells. Energy-dispersive X-ray fluorescence (EDXRF) was used to quantify the nutrients K, Ca, Mn, Fe, Cu, and Zn present in the cells. The reproducibility and accuracy of the technique were demonstrated by analysis of biological reference materials. Exposure of sycamore cells to cadmium had induced variation in the content of some elements. Mn, Cu, Zn, and, particularly, Fe concentrations in cells exposed to Cd were higher than those found in control cells. Ca is adsorbed on the cell walls and the concentration of K is not affected by the presence of Cd.

Cadmium↗

PubMed2002

Interhemispheric connections between primary visual areas: beyond the midline rule.

In the last five years, a number of detailed anatomical, electrophysiological, optical imaging and simulation studies performed in a variety of non-human species have revealed that the functional organization of callosal connections between primary visual areas is more elaborate than previously thought. Callosal cell bodies and terminals are clustered in columns whose correspondence to features mapped in the visual cortex, such as orientation and ocularity, are starting to be understood. Callosal connections are not restricted to the vertical midline representation nor do they establish merely point-to-point retinotopic correspondences across the hemispheres, as traditionally believed. In addition, anatomical studies have revealed the existence of an ipsilateral component of callosal axons. The aim of this short review is to propose how these new data can be integrated into an updated scheme of the circuits responsible for assembling the primary visual field map.

Animals↗

PubMed2001

[Men participation in contraception according to women's perspective].

OBJECTIVE: To identify women's perceptions on men's participation in contraception. METHODS: Home interviews in the southern region of the city of S. Paulo, SP, Brazil, were carried out. The participant sample was of 254 female users of reversible contraceptive methods, who claimed to have sexual partners at moment of the interview. Statistical analysis of the demographic variables and content analysis techniques of the open questions were performed. RESULTS: In 78.8% of the cases, the contraceptive method of choice was of exclusive female use (pills, injectable, IUD, diaphragm). In spite of the high prevalence of female contraceptive methods, 82.7% of the participants asserted that their male partners were active participants in the contraception, which shows a discrepancy between the method used and their perception on men's participation. The main categories concerning women's perceptions on men's participation in contraception were: men support for the women to use female contraceptive methods and the occasional use by men of male contraceptive method when a woman needs to temporarily interrupt the use of her current contraceptive method. CONCLUSIONS: Women perceive men's participation in contraception as a support for them to use contraceptive methods that are highly efficient. The partner's support may be translated by buying the contraceptive pills, reminding the woman of taking them or expressing their opinion about the desired number of children. Women see contraception as an activity of her responsibility and their partners have an auxiliary role.

Adolescent↗

PubMed1997

[Profile of self-medication in Brazil].

INTRODUCTION: The data presented are part of a World Health Organization (WHO) multicenter study of self-medication in Latin America. Brazilian sites included: Belo Horizonte, Fortaleza, the city of S. Paulo and outlying locations. The objective was to characterize self-medication practices by analyzing drugs sought by consumers in pharmacies without a physician's prescription. MATERIAL AND METHOD: Drugs were classified according to the Anatomic Therapeutic Classification codes, and analyzed with respect to 1) intrinsic value; 2) recognition as an essential drug (by either WHO or Brazil); 3) number of active ingredients; and 4) requirement for prescription. RESULTS: Five thousand, three hundred and thirty-two (5,332) different drugs, with 785 distinct active ingredients were sought. Of these, 49.5% were fixed dose combinations, 53.0% were of little intrinsic value, 44.1% required a physician's prescription, 71.0% were not essential drugs, and 40.0% of requests were based on prior prescriptions from the physician. The drugs most requested were analgesics (17.3%), nasal descongestants (7.0%), antirheumatic anti-inflammatory drugs (5.6%), and systemic anti-infective drugs (5.6%). CONCLUSIONS: Self-medication in Brazil reflects the needs and habits of the population. It is strongly influenced by physician's-prescribing habits and by the inadequate selectivity of the Brazilian pharmaceutical market.

Adult↗

PubMed1995

[Reliability of the certification of the basic causes of neonatal deaths: implications for the study of preventable mortality].

The main causes of neonatal mortality, the reliability of the underlying cause of death registered in the death certificate, and the impact of problems of reliability on the analysis of preventable death were studied. The information on death certificates from a 15% sample of neonatal deaths between May 1986 and April 1987 in the Greater Metropolitan Region of Rio de Janeiro was compared to the information in the hospital records of the 452 deceased infants. A "modified underlying cause" considered most correct according to disease classification rules was identified from the records. The great majority of deaths (87%) were due to perinatal causes. Agreement between the originally declared and modified underlying causes of death was poor: 38% for 3 digits of the International Classification of Diseases Codes (CID-9) and 33% for 4 digits. The modified underlying causes are more weighted towards maternal conditions and complications, which increased by a factor of 12.8, and towards complications of the placenta, umbilical cord, labour and delivery, which rose by a factor of 6.2 in relation to the original causes. The utilization of the "modified" underlying cause elevated considerably (58%) the proportion of deaths considered reducible by the classification of neonatal death proposed by the SEADE Foundation. Seventy-five percent (75%) of deaths were considered reducible or partially reducible. One hundred and seven (24%) of the deaths of them being in infants of normal birthweight, of which 60% considered preventable. Four (4) deaths from congenital syphilis, 3 from perinatal hemolytic diseases, and 21 unattended home deaths of infants were also identified. In summary, important problems were identified in the reliability of the declaration of the underlying causes of neonatal death, whose correction tends to elevate the proportion considered reducible or preventable. The potential for the use of death certificate data for the monitoring of quality is evident, nonetheless improvements are needed in the quality of these data.

Birth Weight↗

PubMed1995

[The use of serological tests for detecting HIV infection in general clinical consultations and hospital consultations].

AIMS: To determine the number and type of HIV tests requested in general practice (GP) and in hospital outpatient clinics, to identify principle risk behaviors, to determine the percentage of HIV positive tests and to identify possible factors associated with the request of HIV tests. METHODS: Cross-sectional, analytical and observational study, involving 80 GPs and 45 hospital specialists in the region of Lisbon. All requests for HIV tests were analysed during a 12 month period. RESULTS: 936 HIV tests were requested, with a mean of 12.47 in GP and 0.69 in the hospital. Risk behaviors observed were mainly heterosexual contacts and intravenous drug abuse (IVDA). The motives of the requests mainly were pregnancy, risk behaviors in GP and the presence of symptoms suggesting HIV infection in the hospital. The initiative of the request came from doctors in 70% of the cases. The percentage of HIV positive tests (ELISA + Western blot) was 4.2% in GP and 32% in the hospital. According to risk behaviors, the percentage of seropositivity was 33% in homo/bisexuals, 13% in IVDA, 7% in heterosexuals with risk behaviors and 0.2% in individuals with unidentified risk behaviors. CONCLUSIONS: The patterns of request of HIV tests differ in hospital and in GP. In a significant percentage of cases, no informed consent was obtained prior to HIV testing, both in hospital and GP. This study may serve as an indicator of the need for information and education programs concerning HIV testing directed to health professionals and the general population.

Adult↗

PubMedDate not supplied

[Phlebotomus (Diptera, Phlebotominae) from Saint Luis Island, Maranhão Gulf region, Brazil].

This study lists 32 species of sand flies, 1 of them belonging to the genus Brumptomyia and 31 to the genus Lutzomyia, distributed among the following subgenera: Psychodopygus (6), Nyssomyia (5), Pressatia (3), Evandromyia (2), Psathyromyia (2), Sciopemyia (2), Lutzomyia (1), Micropygomyia (1), Viannamyia (1), and the groups Oswaldoi (5) and Migonei (3). The sand flies were captured in the wild (forest) and in peridomicile (pigpen, hen house and stable) and intradomicile (bedroom) areas from 06:00 PM to 06:00 AM, once a month, for 4 years on the Island of São Luis, Maranhão. All species sampled were present in the forest. Among them, 16 were found in the peridomicile, while 11 were found inside the houses. A total of 22,581 specimens were captured, 65.1% of them in the peridomicile, 17.5% in the forest and 17.4% in the intradomicile. The most common species was Lutzomyia longipalpis (66.4% of the captured specimens), followed by Lutzomyia whitmani (24%) and Lutzomyia evandroi (5.9%). The remaining 29 species represented 3.7% of the total sample.

Animals↗

PubMedDate not supplied

[Laser therapy of inflammatory lesions of the soft parts of the locomotor system].

Soft Laser has been suggested as a useful tool in the management of a large number of pathologies. The aim of this study has been to test the utility of this radiation in the treatment of some Locomotor Apparatus Soft Tissues Inflammatory Conditions. One hundred and fourteen patients with clinical data suggesting tendinitis, bursitis or enthesitis entered this study; 97 patients (Group I) were treated with Infra-Red or/and Helion-Neon Laser using a pontual and/or a scanning technique. The remaining 17 patients were considered as a comparison group (Group II). For evaluation purposes, a semi-quantitative data file was used and the pain, mobility, edema and muscular status were observed. The observation of these items was done prior, two weeks and one month after the Laser treatment. Results were classified as positive when complete or significant remission of symptoms and signs were observed, and negative when there was no improvement or a very slight regression of the complaints observed. A significant difference (p. 001) between Group I and II was found; the acute cases registered better results than the chronic ones (86.8% positive results versus 69.4%). The shoulder patients showed the worst results with only 62% positive cases. Significant differences among the different kinds of Laser applications weren't found. This study seems to confirm the Soft Laser utility in the treatment of the Locomotor Apparatus Soft Tissues Inflammatory lesions.

Adolescent↗

PubMedDate not supplied