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Biomedical subjects

M Fonseca

Publications and source records attributed to M Fonseca.

At least 19 recordsLinked to original sources
PubMed2005

Analysis of the influence of the variable size on the characteristics and behavior of meningiomas.

Seventy-two patients submitted to meningioma surgery at Pedro Hispano Hospital from 1997 to 2001 were reviewed to analyze the association between size (largest diameter of the lesion obtained from imaging examinations) and other variables regarding the biological behavior and clinical outcome of these patients. Statistically significant associations were found between tumor size and location, type of first symptom, type of physical examination, histological grade, surgical complications, postoperative CSF bursae and the need for blood transfusion. Patient's age, gender, duration of first symptom, clinical status at discharge and persistent complaints were not associated to tumor size. There was a trend towards a statistically significant association between tumor size and both grade of resection and persistent deficits. The causes and implications of the findings are discussed. Tumor size is a parameter that may interfere with the neurosurgeon's capacity to treat these patients as well as with their recovery.

Adult↗
PubMed2004

HIV-1 genetic variants circulation in the North of Angola.

Few molecular epidemiological data on HIV-1 in Angola are available. In this study, we analysed 37 pol sequences from patients originated from Luanda and Cabinda in Angola. It was our objective to investigate the circulation of different HIV-1 subtypes in this country. We found a high HIV-1 genetic diversity. The predominant subtypes were C and F, while subtypes A, D, G and H were also detected. Three sequences were untypable and may possibly belong to new subtypes or recombinants of unknown subtypes. Moreover, 13 recombinant sequences were found, most of them with very complex patterns including untypable fragments.

Angola↗
PubMed2003

Extremely short stature: influence of each parent's height on clinical-biological features.

UNLABELLED: Idiopathic extremely short stature probably has several causes. OBJECTIVE: To evaluate the influence of each parent's height on clinical-biological features. METHODS: 57 patients without intrauterine growth retardation seen at 7.9 +/- 0.4 years for height < or = -3 SD were classified according to the difference between their target height and actual height: < 2 SD in familial short stature (FSS, n = 28) and >2 SD in non-FSS (n = 29). RESULTS: Height decreased from -0.5 +/- 0.1 SD at birth to -2 +/- 0.2 SD at 1 year and -2.7 +/- 0.1 SD at 3 years, but the changes in the two groups were similar. FSS children were shorter than non-FSS children both at birth (p = 0.03) and as adults after growth hormone (GH) treatment (p < 0.05), but their plasma insulin-like growth factor I concentrations and GH peaks were similar. The FSS children fathers' heights were more frequently below -2 SD (64%) than the mothers' heights (35%) and were correlated with height at first evaluation (p < 0.05). For the whole population, the mothers' heights were correlated with birth weight (p < 0.05) and with height at first evaluation (p < 0.03). CONCLUSION: This study confirms the influence of the mother's height on birth weight and shows how of the father's height influences idiopathic extremely short stature.

Adolescent↗
PubMed2002

[@HOME is a new Eu-Project in Tele Home care].

@Home is a robust platform for real-time remote monitoring of patients at their home by doctors at the hospital. Health monitoring sensors, which have the capability to measure quick and easy vital parameters such as blood pressure, pulse rate, temperature, oxygen saturation (SpO2), as well as ECG 12 leads are used. Additionally, an advantage of the platform is that all the sensors are wearable and the patient is able to walk around indoors or outdoors. Moreover, the sensors are able to convey the recorded data over Bluetooth, a short-range wireless communication, to any Bluetooth enabled device such as Desktop computer or a Pocket PC.

Computer Communication Networks↗
PubMed2001

A functional assay for paralytic shellfish toxins that uses recombinant sodium channels.

Saxitoxin (STX) and its derivatives are highly toxic natural compounds produced by dinoflagellates commonly present in marine phytoplankton. During algal blooms ("red tides"), shellfish accumulate saxitoxins leading to paralytic shellfish poisoning (PSP) in human consumers. PSP is a consequence of the high-affinity block of voltage-dependent Na channels in neuronal and muscle cells. PSP poses a significant public health threat and an enormous economic challenge to the shellfish industry worldwide. The standard screening method for marine toxins is the mouse mortality bioassay that is ethically problematic, costly and time-consuming. We report here an alternative, functional assay based on electrical recordings in cultured cells stably expressing a PSP target molecule, the STX-sensitive skeletal muscle Na channel. STX-equivalent concentration in the extracts was calibrated by comparison with purified STX, yielding a highly significant correlation (R=0.95; N=30) between electrophysiological determinations and the values obtained by conventional methods. This simple, economical, and reproducible assay obviates the need to sacrifice millions of animals in mandatory paralytic shellfish toxin screening programs.

Animals↗
PubMed2000

Expansions of CD8+CD28- and CD8+TcRVbeta5.2+ T cells in peripheral blood of heavy alcohol drinkers.

BACKGROUND: Despite heavy alcohol consumption, only a low percentage of heavy drinkers develop liver disease. Imbalances in T-cell subsets and iron metabolism parameters are common findings in heavy drinkers, yet the possible role played by discrete T-lymphocyte subsets under heavy alcohol consumption remains unclear. METHODS: To gain new insights into the possible role played by T lymphocytes during alcohol consumption, characterization of CD28 expression and TcR repertoire in peripheral blood CD4+ and CD8+ T cells by two and three-color flow cytometry was performed. A group of heavy alcohol drinkers (AHD, n = 71) and a group of age-matched controls (n = 81), both HLA-phenotyped and HFE-genotyped, constituted the groups under study. RESULTS: Marked expansions of CD28- T cells within the CD8+ but not the CD4+ T-cell pool were observed in AHD compared with controls. These CD8+CD28- expansions were paralleled by expansions of CD8+ T cells bearing specific TcR Valpha/beta chains, namely VP5.2. Moreover, AHD, but not controls, carrying the H63D mutation in the HFE gene showed significantly higher percentages of CD28- T cells within the CD8+ T-cell pool than AHD carrying the normal HFE gene. Finally, high numbers of CD8+CD28- T cells in AHD were associated with lower levels of the liver-related enzymes ALT and GGT. CONCLUSIONS: This study showed that under active ethanol consumption, expansions of discrete CD8+ T-cell subsets occur within the CD8+ T-cell pool, that molecules of the MHC-class I locus seem to influence the extent of the expansions, and that high numbers of CD8+CD28- T cells are associated with low levels of liver enzymes in AHD.

Adult↗
PubMed2000

[Morphology of the cells in myxoid tumors].

We describe a morphologic study of myxoid cells in myxoid tumors or with myxoid regions: myxoid fibrosarcoma, myxoma, myxoid liposarcoma, embryonal rhabdomyosarcoma, chondroma, chondrosarcoma, myxoid leiomyosarcoma, schwannoma, and odontoameloblastoma; and we compare with fibroblasts of umbilical cord, embryonal mesenquima and loose connective tissue in inflammatory conditions. Histologic techniques: H-E, PAS, Masson's trichrom, and Del Río Hortega's panoptic silver staining. Histologically Del Río Hortega's technique reveals bipolar fibroblasts with long processes. In myxoma and myxoid fibrosarcoma they are stellated with abundant processes and mucin cytoplasm secretion contained in bowls that slides through cytoplasmic expansions and discharge into intercellular space. The lipoblasts of myxoid liposarcoma are also stellated with abundant processes and contain drops of lipids. The rhabdomyoblasts are raquetoid cells with cross striated cytoplasm, myofibrils and cigar-shaped nuclei. Schwannomas are composed of spindle and bipolar cells with long and thin cytoplasmic extensions. The chondroblasts in chondromas and chondrosarcomas have wide cytoplasm with short processes. The odontoblasts in odontoameloblastomas have wide cytoplasm and long processes directly extended toward adjacent dentinal. These morphologic details can help in the differential diagnosis associated with immunoperoxidase stains.

Adolescent↗
PubMed1998

No evidence for a significant non-nitrergic, hyperpolarising factor contribution to field stimulation-induced relaxation of the mouse anococcygeus.

1. The aim of the study was to determine whether a nerve-derived hyperpolarizing factor (NDHF) might contribute to non-adrenergic, non-cholinergic (NANC) relaxations of the mouse anococcygeus when low concentrations of contractile agent are used to raise tone and low frequencies of field stimulation applied; such a non-nitrergic NDHF has been proposed to contribute to NANC relaxations of the rat anococcygeus and guinea-pig taenia coli. 2. Phenylephrine (0.1-100 microM) produced concentration-related contractions of the mouse isolated anococcygeus muscle; 0.2 microM phenylephrine (EC26) was used to raise tone in subsequent experiments. 3. Field stimulation (0.5, 1.0 and 5.0 Hz) produced frequency-dependent relaxations of phenylephrine-induced tone. In the presence of the nitric oxide synthase inhibitor L-NG-nitro-arginine (L-NOARG; 100 microM), the soluble guanylate cyclase inhibitor 1H-[1,2,4]oxodiazolo[4,3-a]quinoxalin-1-one (ODQ; 5 microM), or a combination of these two drugs, relaxations to field stimulation were abolished at all frequencies studied. Relaxations to sodium nitroprusside (0.01-5 microM) were unaffected by L-NOARG but strongly inhibited by ODQ; neither enzyme inhibitor affected relaxations to 8-Br-cyclic GMP (10 microM). 4. Nifedipine (1 microM) reduced the contractile response to 0.2 microM phenylephrine by 38%; however, it had no effect on NANC relaxations. 5. It is concluded that NANC relaxations of the mouse anococcygeus are purely nitrergic and that there is no significant contribution from a putative NDHF.

Adrenergic alpha-Agonists↗
PubMed1997

Symmetrical enchondromatosis of the hands and feet in two sisters.

We report two Portuguese sisters aged 9 and 12 years with symmetric well-circumscribed radiolucent cystic lesions on the long bone metaphysis of the hands and feet. The eldest also has soft tissue calcifications. They have no dysmorphic features and their growth is normal. Plasma values of parathyroid hormone (PTH), calcium, phosphorus, magnesium, and alkaline phosphatase are normal. Cerebral computed tomography (CT) scan shows no intracranial calcifications. A Raynaud phenomenon became evident during the last year in the eldest. The incisional biopsy of the left proximal metatarsial was performed through an area of typical radiographic appearance. The pathology specimen consisted of enchondroma tissue. The present cases are an extremely rare instance of this pathology, with symmetrical involvement of the hands and feet and a familial incidence.

Adolescent↗
PubMed1997

[Early luminal diameter reduction after coronary angioplasty and its relation to the restenosis phenomenon].

PURPOSE: To evaluate the early luminal diameter loss in the first 15 min after percutaneous transluminal coronary angioplasty (PTCA) and its influence on coronary restenosis. METHODS: In a prospective study, we evaluated 86 patients. The patients were divided in two groups based on the presence or absence of coronary restenosis. Thirty one lesions developed restenosis and 55 lesions did not. RESULTS: Univariate analysis showed that balloon/artery ratio was lower in the group of restenosis (0.92 +/- 0.01 vs 1.00 +/- 0.11, P = .003). Absolute and relative elastic recoil at 1 min was greater in the group that developed restenosis (0.79 +/- 0.54 vs 0.68 +/- 0.59 mm; P = .007 and 32.04 +/- 14.27 vs 22.15 +/- 16.65%; P = .006). Similarly, absolute and relative elastic recoil at 15 min were greater in the group with restenosis (1.25 +/- 0.59 vs 0.90 +/- 0.65 mm, P = .017 e 46.75 +/- 15.69 vs 29.18 +/- 17.84%, P < .00001). Minimal luminal diameter (MLD) at 1 min was lower in the group with restenosis (2.15 +/- 0.42 vs 2.43 +/- 0.58 mm; P = .022). The very early loss was greater in the group with restenosis (0.46 +/- 0.34 vs 0.22 +/- 0.35 mm, P = .004). MLD at 15 min was lower in the group of restenosis than in the group without restenosis (1.69 +/- 0.48 vs 2.20 +/- 0.61; P = .0001). Multivariate analysis revealed balloon/artery ratio and MLD at 15 min as independent correlates of the late outcome. CONCLUSION: The late outcome of PTCA is influenced by elastic recoil and the early MLD loss after PTCA. However, the strongest and most important predictors of late outcome by multivariate analysis were balloon/artery ratio and MLD at 15 min.

Angioplasty, Balloon, Coronary↗
PubMed1997

Comparative study of AgNOR and PCNA in experimental carcinogenesis of salivary glands of rats.

Previous studies regarding experimental carcinogenesis demonstrated that submaxillar glands (GSM) submitted to DMBA present cellular modifications of progressive gravity in different periods after eight days of the experiment (J. Dent. Res 59: 1067, 1980). This current work pursues the objective of determining, quantitatively, regions of nucleolar organizations (AgNOR) and immunomarkation of the antigen of nuclear proliferation (PCNA) for their possible link with the morphostructural findings previously described. By means of argentic impregnation, the AgNOR were identified. The histometric was performed according to the numeric parameters of AgNOR per nucleus (CABRINI et al. 1992) immersed 1000x. A triple blind reading of the five randomly chosen studies from each of the twenty cases studies with distinct experimentation stages was completed. The results were compared to the normal areas (control group). The PCNA was determined immunohistochemically (Avidina-Biotina System Dako). The average number of AgNOR was 11 after eight days; 16 after fifteen days and 12 after twenty days of the experiment (100% adenocarcinoma). In the control group, the average number of AgNOR did not exceed 6. The PCNA after eight days was negative. The reaction in the tumor area was between 20 and 30% positive. The results indicate an increase in the number of AgNOR in relation to the neoplastic proliferation, corroborated by PCNA immunodetection.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1996

Transmission-ratio distortion through F1 females at chromosome 11 loci linked to Om in the mouse DDK syndrome.

We determined the genotypes of > 200 offspring that are survivors of matings between female reciprocal F1 hybrids (between the DDK and C57BL/6J inbred mouse strains) and C57BL/6J males at markers linked to the Ovum mutant (Om) locus on chromosome 11. In contrast to the expectations of our previous genetic model to explain the "DDK syndrome, " the genotypes of these offspring do not reflect preferential survival of individuals that receive C57BL/6J alleles from the F1 females in the region of chromosome 11 to which the Om locus has been mapped. In fact, we observe significant transmission-ratio distortion in favor of DDK alleles in this region. These results are also in contrast to the expectations of Wakasugi's genetic model for the inheritance of Om, in which he proposed equal transmission of DDK and non-DDK alleles from F1 females. We propose that the results of these experiments may be explained by reduced expression of the maternal DDK Om allele or expression of the maternal DDK Om allele in only a portion of the ova of F1 females.

Animals↗
PubMed1996

[Taxonomic study of species of the Mycobacterium genus isolated in Cuba].

40 strains of the Mycobacterium genus corresponding to 12 species, which were subjected to 62 microbiological and biochemical tests, were studied. Each one was considered as a character. As a result of the similitude coefficient and their grouping, 9 phenomes represented by: Phenome I (Mycobacterium fortuitum), Phenome II (MAI Complex), Phenome III (Mycobacterium phlei), Phenome IV (Mycobacterium triviale), Phenome V (Mycobacterium smegmatis), Phenome VI (Mycobacterium gordonae), Phenome VII (Mycobacterium szulgai), Phenome VIII (MAI Complex), and Phenome IX (Mycobacterium scrofulaceum), were obtained. The strain identification work was consistent with grouping from the phenotypic point of view.

Cuba↗
PubMed1995

Development of calretinin immunoreactivity in the neocortex of the rat.

The prenatal and postnatal development of calretinin (CR)-containing elements in the neocortex of the rat was analyzed using immunohistochemistry. CR immunoreactivity in the cortical anlage appeared early at embryonic day 14 (E14), with CR-positive neurons located in the primitive plexiform layer and in the emerging subplate and marginal zones. At later prenatal and early postnatal stages, these two layers showed the highest CR immunostaining in the cortex, and large numbers of cell bodies and fibers were immunostained. From postnatal day 3 (P3) onwards, CR immunostaining disappeared progressively from the subplate-layer VIb and the marginal zone-layer I, so that very few cells remained stained in these layers in the adult. In the cortical plate and prospective layers VIa to II-III, CR-positive neurons were seen at prenatal stages, their numbers increasing markedly during the first postnatal week. Most neurons showed undifferentiated nonpyramidal shapes, and matured during the second and third postnatal weeks, when the adult pattern of CR immunostaining was achieved. In addition, some pyramidal-like neurons in the infragranular layers and in layer II-III transiently expressed CR during the postnatal period, most notably between P3 and P12. Colocalization experiments performed at P0-P3 with antibodies against the neurotransmitter gamma-aminobutyric acid (GABA) showed that most nonpyramidal CR-positive neurons in the derivates of the cortical plate were also GABAergic during development. In contrast, large numbers of CR-containing neurons in the subplate and marginal zone were GABA-negative. The present results show that in addition to recording the early development of a subset of nonpyramidal neurons, CR is transiently expressed in certain GABA-negative populations of the subplate and marginal zone, and most likely in pyramidal neurons.

Animals↗
PubMed1995

Calretinin-immunoreactive neurons in the normal human temporal cortex and in Alzheimer's disease.

Calretinin-containing neurons (CR) were visualized by immunocytochemistry in the human temporal cortex. The morphology of calretinin-positive neurons ranged from bipolar, bitufted, fusiform to double bouquet cells, whose long axis was parallel to the radial axis of the cortex. Calretinin-immunoreactive cells were more abundant in layers II, III and less frequent in layer VI and white matter. In layer I, large horizontal neurons resembling Cajal-Retzius cells were observed. Layers IV and V contained few labeled cells. The CR-immunoreactive neuropil was abundant, especially in supragranular layers. However, the most prominent feature of the pattern of calretinin staining was the presence of long, vertically oriented bundles of calretinin-immunoreactive processes. These bundles formed a widespread, regular columnar system descending throughout layers II to VI. Despite the virtually identical morphological features of CR-immunoreactive neurons and certain calbindin-immunoreactive neurons, colocalization studies for both antibodies against calretinin and calbindin, revealed little coexistence (in supragranular layers) or none (in infragranular layers). Thus, double bouquet cells could be considered as forming a chemically heterogeneous neuronal population. In addition, four brains from patients with Alzheimer's disease were immunostained for calretinin. No major differences from normal brains were found; the distribution, morphology and the characteristic, vertically oriented bundles resembled those described in normal brains. These data suggest that these calcium-binding protein-containing interneurons are present in normal human brain and that they are resistant to degeneration in Alzheimer's disease.

Aged↗
PubMed1995

Transmission-ratio distortion of X chromosomes among male offspring of females with skewed X-inactivation.

We have begun a search for heritable variation in X-chromosome inactivation pattern in normal females to determine whether there is a genetic effect on the imprinting of X-chromosome inactivation in humans. We have performed a quantitative analysis of X-chromosome inactivation in lymphocytes from mothers in normal, three-generation families. Eight mothers and 12 grandmothers exhibited evidence of highly skewed patterns of X-chromosome inactivation. We observed that the male offspring of females with skewed X-inactivation patterns were three times more likely to inherit alleles at loci that were located on the inactive X chromosome (Xi) than the active X chromosome (Xa). The region of the X chromosome for which this phenomenon was observed extends from Xp11 to -Xq22. We have also examined X-chromosome inactivation patterns in 21 unaffected mothers of male bilateral sporadic retinoblastoma patients. Six of these mothers had skewed patterns of X-chromosome inactivation. In contrast to the tendency for male offspring of skewed mothers from nondisease families to inherit alleles from the inactive X chromosome, five of the six affected males inherited the androgen receptor alleles from the active X chromosome of their mother.

Base Sequence↗
PubMed1995

The department of Veterans Affairs oral health services and eligibility.

The Department of Veterans Affairs (VA) operates one of the largest health care systems in the nation; more than 2.5 million veterans receive care annually. Among the special foci of care within VA is the Dental Service. The Department of Veterans Affairs Dental Service is the largest dental care system in the nation and the largest hospital-based dental care system in the world, receiving more than 1.2 million visits annually. The authors describe the VA dental care system and the larger health care system in which it is embedded. How the system is organized, who is eligible for services, who uses care, and what types of services are used are detailed. Compared with medical care, eligibility for VA dental care is more complex and differs for inpatients and outpatients. Outpatients account for 65% of patient visits and 76% of treatment provided in VA dental clinics. The two largest groups of users are inpatients with compelling medical needs (17%) and outpatients who are totally disabled (24%). A wide variety of services is provided, ranging from diagnostic and preventive care to insertion of crowns, bridges, and removable prostheses. Changes in the nation's health care system mandate introspection by all health agencies. The goal of the VA Dental Service is to become veterans' first choice for dental care. Information needed by VA to best respond to the needs of veterans include the following: (1) reasons for why eligible veterans do not use VA dental care; (2) veterans' oral health needs; (3) definition of optimum care and whether it varies as a person moves from functional independence to dependence; (4) whether VA is providing the most cost-efficient care possible and is best utilizing allied health professions; and (5) whether this care is best provided in a hospital setting. Modifications of data gathering systems are required as a first step to providing the needed information.

Aged↗