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Biomedical subjects

V Alves

Publications and source records attributed to V Alves.

10 recordsLinked to original sources
PubMed2006

Elevated neopterin levels in non-allergic asthma.

Neopterin is synthesized by human monocyte-derived macrophages upon stimulation with interferon-gamma (IFN-gamma). Measurement of neopterin concentration is useful to monitor cell-mediated (Th1-type) immune activation. In this study, we aimed to analyze the behaviour of neopterin in long lasting asthma considering its role as a marker of the Th1 environment and to establish the distinction between patients belonging either to the allergic or the non-allergic population, particularly in the elderly where asthma is often under diagnosed. Therefore we evaluated allergic parameters such as skin prick tests, IgE and hemogram (eosinophils count), and we compared our findings with neopterin values found in an age-matched control population. A group of individuals older than 65 was selected. It included 64 asthmatic patients (mean age 72+/-5 years) and 41 healthy individuals (mean age 79+/-7 years). In our study population, 42 patients presented positive skin tests, mainly to house dust mites. All patients were clinically stable and presented an average percentage of predicted forced expiratory volume in the first second (FEV1) of 73.6+/-25.3 and predicted median expiratory flow percentage (MEF50) of 38.8+/-26.7. Blood cell counts showed statistically different mean values of eosinophils between allergic and non-allergic controls (5.42+/-4.7% versus 2.8+/-2.8%; p<0.04). IgE values were increased in allergic asthmatic patients when compared with non-allergic asthmatic patients (493.2+/-549.8IU/ml versus 85.3+/-194.4IU/ml; p=0.000). Allergic asthmatic patients presented mean neopterin levels similar to those found in the control group (2.4+/-2.8ng/ml versus 2.1+/-1.9ng/ml). In contrast, in non-allergic asthmatic patients these values were higher when compared with the control group (4.0+/-4.7ng/ml versus 2.1+/-1.9ng/ml). Neopterin levels were lower in allergic asthmatic patients when compared with non-allergic asthmatic patients (2.4+/-2.8ng/ml versus 4.0+/-4.7ng/ml). Within asthmatic patients, those with higher neopterin values (>2.1ng/ml) presented lower mean IgE values (IgE</=336.58IU) than those with lower neopterin values (</=2.1ng/ml) who presented mean IgE values of 402.70IU. Our initial findings may lead to a better understanding of the immunoinflammatory pathways in asthma. Further studies will probably show that serum neopterin could became a useful marker for asthma classification including in elderly patients with long lasting disease.

Journal Article↗
PubMed2005

Tremor as the first neurological manifestation of Sneddon's syndrome.

We report on a 54-year-old woman with Sneddon's syndrome manifested by livedo reticularis, fetal losses, hypertension, and high antinuclear antibody titres. At the age of 42 years she developed tremor of the trunk, limbs, and head only in the standing position that interfered with walking, followed some years later by cognitive decline and a parkinsonian syndrome. T2-weighted brain magnetic resonance imaging showed high signal in cortical areas, basal ganglia, midbrain, and cerebellum.

Anticonvulsants↗
PubMed2002

Abnormalities in dendritic cell and macrophage accumulation in the pancreas of nonobese diabetic (NOD) mice during the early neonatal period.

Dendritic cell (DC), macrophage (Mphi) and lymphocyte infiltrations have been observed in normal human perinatal pancreata, but have never been investigated so early in control mice. In type 1 diabetes-prone NOD mice, these cells are thought to infiltrate first the periphery of the islets of Langerhans around weaning before further islet infiltration and beta-cell destruction. We quantified, during the first month of life, the numbers of DC (characterized by CD11c positivity and dendritic morphology), histiocyte-like Mphi (characterized by ER-MP23 positivity) and Mphi with scavenging potential (characterized by BM8 positivity) in C57BL/6, DBA/2 and BALB/c control, and NOD and lymphocyte-deficient NODscid mouse pancreata. First, CD11c+ DC were present at low densities from birth onwards in control pancreata, while densities were higher in NOD and NODscid. Second, high numbers of BM8+ and ER-MP23+ Mphi were observed at birth in all strains investigated. After birth, particularly BM8+ cells disappeared progressively in control strains, but not in NOD and NODscid. Third, NOD mice also had more ER-MP23+ Mphi at birth compared to controls. Finally, DC and Mphi localizations were similar in all strains, i.e., mostly as dispersed cells in perivascular, periductular, peri-islet areas and interlobular septa. The most remarkable finding was that particularly BM8+ Mphi, were seen at sites of islet neogenesis and predominantly at the duct-islet interface. Our data showed that different types of APC were present in the pancreas during postnatal development in various control mouse strains and some differences were observed in NOD and NODscid mice from birth onwards.

Animals↗
PubMed2001

Diabetes increases the expression of hypothalamic neuropeptides in a spontaneous model of type I diabetes, the nonobese diabetic (NOD) mouse.

1. Synthesis of oxytocin (OT) and arginine-vasopressin (AVP) is increased in induced models of Type I diabetes, such as the streptozotocin model. However, these parameters have not yet been evaluated in spontaneous models, such as the nonobese diabetic mouse (NOD). Therefore, we studied in the magnocellular cells of the paraventricular nucleus (PVN) of nondiabetic and diabetic 16-week-old female NOD mice and control C57B1/6 mice, the immunocytochemistry of OT and AVP peptides and their mRNA expression, using nonisotopic in situ hybridization (ISH). 2. In nondiabetic and diabetic NOD female mice, the number of OT- and AVP-immunoreactive cells were similar to those of the controls, whereas immunoreaction intensity was significantly higher for both peptides in diabetic NOD as compared with nondiabetic NOD and control C57B1/6 mice. 3. ISH analysis showed that the number of OT mRNA-containing cells was in the same range in the three groups, whereas higher number of AVP mRNA expressing cells was found in diabetic NOD mice. However, the intensity of hybridization signal was also higher for both OT and AVP mRNA in the diabetic group as compared with nondiabetic NOD and control mice. 4. Blood chemistry demonstrated that haematrocrit, total plasma proteins, urea, sodium, and potassium were within normal limits in diabetic mice. Thus, NOD mice were neither hypernatremic nor dehydrated. 5. We suggest that upregulation of OT and AVP reflects a high-stress condition in the NOD mice. Diabetes may affect neuropeptide-producing cells of the PVN, with the increased AVP and OT playing a deleterious role on the outcome of the disease.

Animals↗
PubMed1999

A unified framework for data modeling on medical information systems.

Medical Information Systems (MIS) are seen as a way of optimizing the use of existing health-care infrastructure, without resorting to new and costly hospital (re)construction. The qualitative (re)design of such an environment requires a basic understanding of patient and doctors related characteristics and capabilities. Patient care, patient education, medical education, and clinical research need to be considered to meet the basic requirements on the level of services desirable, determined on the basis of the patient's length of stay; i.e., used for modeling the significant entities of such a world. The aim is to extract conclusions for the level of services provided to the users. One's concept will capture, as well as will integrate, the basic design principles under which MIS may be set.

Artificial Intelligence↗
PubMed1995

Attempts to pharmacologically modulate prolactin levels and type 1 autoimmune diabetes in the non-obese diabetic (NOD) mouse.

Prolactin (PRL) is well known for its stimulatory effects on various components of the immune response. Experimentally induced high levels of PRL have been shown to correlate with the worsening of several autoimmune diseases. In contrast, lowering PRL levels may protect from the autoimmune process. We investigated in both sexes of NOD mice a spontaneous model of autoimmune type 1 diabetes, the effects of two drugs, a dopaminergic agonist, bromocriptine (BRC, 10 mg/kg), which is assumed to inhibit PRL secretion, and a dopaminergic antagonist, metoclopramide (MCP, 5 mg/kg), which in contrast stimulates PRL secretion, on the incidence of diabetes, the severity of insulitis, and PRL and glucose levels. Chronic treatment of NOD mice with MCP slightly aggravated development of diabetes. The dopamine antagonist tended to accelerate the onset of diabetes in females and significantly increased the number of islets with peri-insulitis in both sexes. The weak deleterious effects exerted by MCP in NOD mice may be related to its stimulatory action on PRL release. Contrary to the expected results, the dopamine agonist BRC did not protect from autoimmune diabetes. In contrast, the drug appeared to accelerate diabetes onset in males and significantly increased the number of islets showing insulitis in both sexes. This study underlines the complexity of the action of BRC which in NOD mice only transiently inhibits the release of PRL. Moreover, the aggravating actions of BRC may be related to the marked hyperglycemic effect of the drug observed in male and female NOD mice.

Animals↗
PubMedDate not supplied

[Status epilepticus in the childhood. A review of seven years].

INTRODUCTION: Status epilepticus is a neurological emergency that requires early and prompt treatment. PATIENTS AND METHODS: This retrospective study includes 32 children treated for status epilepticus at Hospital Geral de Santo António, from January 1992 to December 1998. We evaluated the clinical features, duration, aetiology and prognostic. RESULTS: Symptomatic or criptogenetic aetiology was present in 53% of children and idiopathic in 47%. 27% of episodes of status epilepticus were induced by fever. The most common neurological sequel was epilepsy (onset of new epilepsy in 20%; aggravated in 25%). Two children (10%) had major neurological sequelae after status epilepticus. CONCLUSION: In our study the duration of status epilepticus and sequelae seems to be related with aetiology.

Acute Disease↗
PubMedDate not supplied

[Immunologic and epidemiologic characterization of non-responders/low-responders to hepatitis B vaccine].

UNLABELLED: An important reduction in morbidity and mortality due to hepatitis B was achieved with the discovery of an effective vaccine. However, 2 to 10% of healthy adults do not respond to vaccination with the production of protective levels of antibody anti-HBs (assumed as protective, concentrations of ab. anti-HBs > 10 UI/L). Therefore, the aim of the present work was to study epidemiological (sex, age, obesity, alcoholic and smoking habits, previous diseases) and immunological factors (white cell count, immunoglobulins and sub-classes of IgG, lymphocytic populations and sub-populations) in a group of 20 healthcare workers with a low response (anti-HBs < 50 UI/L) to a genetically-engineered vaccine (Engerix B). The results were compared to the ones found in an identical sample of responders (anti-HBs > 100 UI/L) from the same population. No statistically significant differences regarding the epidemiological data, differential white cell counts and immunoglobulin quantification (IgG, IgA, IgM, IgG1, IgG2, IgG3) were detected. The mean value of IgG4 (mean = 54.53 +/- 59.8 mg/dl) in non/hyporesponders was significantly higher (p = 0.038) when compared to the same result in responders (mean = 33.76 +/- 31.30 mg/dl). A statistically significant difference (p < 0.05) in the quantification of double negative lymphocytic T sub-populations was also found, the mean value being higher in the responders (mean = 6.5 +/- 4.1% versus 4.6 +/- 2.3%). CONCLUSIONS: The effectiveness of recombinant hepatitis B vaccines is well known. However, a number of apparently healthy people are unable to achieve protective titres of anti-HBs after vaccination. As our study groups did not have a considerable number of cases, we can not establish definitive conclusions based on differences found in the quantification of IgG4 and double negative lymphocytic T sub-populations. It seems to us that an investment in future research into the eventual causes of nonprotective response and into new strategies of immunization of non/hyporesponders are appropriate. In the meantime, the occupational daily risk of exposure to infected body fluids makes adequate hepatitis B immunization of healthcare workers a priority.

Adult↗