Electrochemical behavior and corrosion resistance of Ti-15Mo alloy in naturally-aerated solutions, containing chloride and fluoride ions.

The electrochemical behavior and corrosion resistance of Ti-15Mo alloy to applications as biomaterials in solutions 0.15 mol L(-1) Ringer, 0.15 mol L(-1) Ringer plus 0.036 mol L(-1) NaF and 0.036 mol L(-1) NaF (containing 1,500 ppm of fluoride ions, F(-)) were investigated using open-circuit potential, cyclic voltammetry, and electrochemical impedance spectroscopy techniques, X-ray photoelectron spectroscopy and scanning electron microscope. Corrosion resistance and electrochemical stability of the Ti-15Mo alloy decreased in solutions containing F(-) ions. In all cases, there were formation and growth of TiO2 and MoO3 (a protector film), not being observed pitting corrosion, which might enable Ti-15Mo alloys to be used as biomedical implant, at least in the studied conditions, since the electrochemical stability and corrosion resistance of the passive films formed are necessary conditions for osseointegration.

Transcriptome changes induced by docetaxel in human mammary cell lines expressing different levels of ERBB2.

The taxane docetaxel is currently the most effective chemotherapeutic drug for the treatment of advanced breast cancer. However, a considerable proportion of breast cancer patients do not respond positively to docetaxel. The mechanisms of docetaxel resistance are poorly understood. Overexpression of ERBB2 occurs in 15-30% of breast tumors and is associated with chemoresistance to a variety of anticancer drugs. In the present study, we sought to identify genes involved in ERBB2-mediated chemoresistance to docetaxel. We generated SAGE libraries from two human mammary cell lines expressing basal (HB4a) and high (C5.2) levels of ERBB2 before and after intensive exposure to docetaxel and identified potential ERBB2 target genes implicated in a variety of cellular processes including cell proliferation, cell adhesion, apoptosis and cytoskeleton organization. Comparison of the transcriptome of the cell lines before and after docetaxel exposure revealed substantially different expression patterns. Twenty-one differentially expressed genes between HB4a and C5.2 cell lines, before and after docetaxel treatment, were further analyzed by qPCR. The alterations in the expression patterns in HB4a and C5.2 cell lines in response to docetaxel treatment observed by SAGE analysis were confirmed by qPCR for the majority of the genes analyzed. Our study provides a comprehensive view of the expression changes induced in two human mammary cells expressing different levels of ERBB2 in response to docetaxel that could contribute to the elucidation of the mechanisms involved in ERBB2-mediated chemoresistance in breast cancer.

New potential AChE inhibitor candidates.

We have theoretically studied new potential candidates of acetylcholinesterase (AChE) inhibitors designed from cardanol, a non-isoprenoid phenolic lipid of cashew Anacardium occidentale nut-shell liquid. The electronic structure calculations of fifteen molecule derivatives from cardanol were performed using B3LYP level with 6-31G, 6-31G(d), and 6-311+G(2d,p) basis functions. For this study we used the following groups: methyl, acetyl, N,N-dimethylcarbamoyl, N,N-dimethylamine, N,N-diethylamine, piperidine, pyrrolidine, and N,N-methylbenzylamine. Among the proposed compounds we identified that the structures with substitution by N,N-dimethycarbamoyl, N,N-dimethylamine, and pyrrolidine groups were better correlated to rivastigmine, and represent possible AChE inhibitors against Alzheimer disease.

Toward an understanding of intermediate- and short-range defects in ZnO single crystals. A combined experimental and theoretical study.

A joint use of experimental and theoretical techniques allows us to understand the key role of intermediate- and short-range defects in the structural and electronic properties of ZnO single crystals obtained by means of both conventional hydrothermal and microwave-hydrothermal synthesis methods. X-ray diffraction, Raman spectra, photoluminescence, scanning electronic and transmission electron microscopies were used to characterize the thermal properties, crystalline and optical features of the obtained nano and microwires ZnO structures. In addition, these properties were further investigated by means of two periodic models, crystalline and disordered ZnO wurtzite structure, and first principles calculations based on density functional theory at the B3LYP level. The theoretical results indicate that the key factor controlling the electronic behavior can be associated with a symmetry breaking process, creating localized electronic levels above the valence band.

Identification of differentially expressed genes in prostatic epithelium in relation to androgen receptor CAG repeat length.

The CAG repeat within exon 1 of the androgen receptor (AR) has been associated with the development of prostate cancer. The shorter number of glutamine residues in the protein has been associated with a higher transcriptional activity of the AR and increased relative risk for prostate cancer. In an attempt to identify differentially expressed genes in prostate cancer in relation to AR CAG repeat length variation, in this study we used total mRNA from normal and tumor tissues from 2 prostate cancer patients with AR alleles containing 19 and 26 CAG repeats to perform differential-display RT-PCR analysis. We were able to identify 48 different transcripts that showed homology to several known genes associated with different biological pathways. Among the differentially expressed genes, ATRX and SFRP1 were further validated by quantitative RT-PCR. The transcripts of both ATRX and SFRP1 genes proved to be down-regulated in most of the prostate tumors analyzed by quantitative RT-PCR. Hypermethylation of the promoter region of the SFRP1 gene was found in 17.5% (7/40) of the cases analyzed and was associated with the loss of SFRP1 expression (p=0.014). The differentially expressed genes identified in this study are implicated in several cellular pathways that, when up- or down-regulated, might play a role in the tumorigenic process of the prostate.

Comparison of six methods for the extraction of lipids from serum in terms of effectiveness and protein preservation.

The present work compares six biochemical methods for extraction of lipids from human serum. Although some organic solvents were good lipid extractors, they precipitated most of the total proteins and albumin. On the other hand, methodologies using Triton X-114 and silica were efficient for extraction of lipids, while sparing the protein fraction.

The CAG repeat polymorphism in the androgen receptor gene (AR) and its relationship to head and neck cancer.

Sex hormones may play an important role in the tumorigenic process of the head and neck. The aim of our work was to investigate whether the androgen receptor (AR) CAG repeat polymorphism is associated with an increased relative risk for head and neck cancer. Genomic DNA from 103 male patients with head and neck carcinomas and 100 male controls were analyzed for the AR CAG polymorphism by PCR amplification and direct sequencing or denaturing polyacrilamide gel electrophoresis. Logistic regression analysis showed a significant association between CAG repeat length and risk of head and neck cancer in individuals with more than 20 CAG repeats [OR=2.54 (95% CI, 1.3-4.8)]. For the group of individuals with oral and laryngeal cancer the estimated relative risk was increased to 2.79 (95% CI, 1.2-6.3) and 3.06 (95% CI, 1.0-9.6), respectively, in men with CAG repeat length >20. These results suggest, for the first time, that shorter AR CAG repeat alleles have a protective effect for head and neck cancer development.

[Fatal necro-hemorrhagic pancreatitis related to sodium valproate: case report]. / Pancreatite necro-hemorrágica fatal associada ao uso de valproato de sódio: relato de caso.

Among the idiosyncratic reactions related to VPA, pancreatitis is the most rare and less remembered even though its potentially fatal course. We report the case of a 5 year-old boy with epilepsy treated with VPA 40 mg/kg/day associated with CBZ 20 mg/kg/day and PB 3 mg/kg/day, admitted for vomiting, abdominal pain, low grade fever, abdominal tension and amylasis of 288 UI. On evolution presented upper digestive hemorrhage, shock and amylasis of 564 UI. The patient was submitted to exploratory laparotomy with findings of hemorrhagic ascitis, retroperitoneal hematoma, increased volume of pancreas with edema and hemorrhage leading to diagnosis of necro-hemorrhagic pancreatitis and a fatal course. Pancreatic complications are well known complications related to VPA treatment and may vary between asymptomatic hyperamilasemy to fatal acute pancreatitis. The characteristics of our patient correlates with the data on literature: we found 7 similar cases reported, 4 of which died.

Mimics of copper proteins: structural and functional aspects.

The importance of copper as an essential element can be estimated by the wide range of copper proteins and enzymes playing different roles in biological systems. In the last decades many bioinorganic studies were developed on mimetic complexes of copper-dependent proteins, in order to verify the interrelations between structural and functional properties of active copper centers. Among the most studied copper ion ligand, diimine compounds have deserved special attention due their flexibility, facility of preparation, and ability to stabilize both oxidation states of this metal. In our laboratory, we have been investigating some Schiff base copper complexes as mimics of different proteins, with emphasis on functional aspects, trying to elucidate mechanisms of reaction, based on proposed intermediary species, in addition to molecular shapes. Particularly, mimics of the copper-zinc superoxide dismutase, and of monooxigenases and oxidases exhibiting dicopper sites are discussed in this work.

Evaluation of the short-form 36-item questionnaire to measure health-related quality of life in patients with idiopathic pulmonary fibrosis.

OBJECTIVE: To validate the use of the 36-item short-form questionnaire (SF-36) for measuring health-related quality of life (HRQL) in patients with idiopathic pulmonary fibrosis (IPF). DESIGN: : Observational data at a single point in time. SETTING: : A specialized outpatient respiratory clinic. PARTICIPANTS: Thirty-four patients (mean +/- SE age, 58.29 +/- 1.87 years) with IPF and no significant comorbidity. A matched control group for HRQL measurements was composed of 34 normal subjects (mean age, 58.00 +/- 1.89 years). MEASUREMENTS AND RESULTS: Dyspnea was measured by the baseline dyspnea index (BDI). Respiratory function evaluation included FVC, FEV(1), and resting arterial blood gases. IPF patients showed a mean BDI score of 5.21 +/- 0.46. The mean FVC and FEV(1) values were 62.41 +/- 2.96% and 66.41 +/- 3.33%, respectively. The mean PaO(2) was 67 +/- 2.51 mm Hg, and the mean PaCO(2) was 37 +/- 1. 05 mm Hg. Patients scored significantly worse than control subjects with respect to the SF-36 domains of physical functioning, physical role, general health perceptions, vitality, social functioning, emotional role, and mental health index. BDI scores were significantly correlated with five SF-36 components, and FVC and FEV(1) were significantly correlated with two SF-36 components. Significant negative correlations were found between arterial pH and four SF-36 domains. CONCLUSIONS: Patients with IPF have a significant impairment of HRQL in both physical and psychological functioning. Dyspnea is the most important factor influencing the quality of life in these subjects. The SF-36 questionnaire is a valid instrument to evaluate HRQL in IPF patients.

[The care of patients with hematologic problems -- a teaching-learning experience]. / O cuidar do cliente com problemas hematológicos--uma experiência de ensino-aprendizagem.

This study presents the experience of a group of students of the nursing graduation course at the Fluminense Federal University regarding the care of patients with hematological problems. It shows how these students deal with the death and suffering when contacting patients with chronic diseases. The investigation also aims at indicating how important these matters are for student's reflexive and critical development during their training period.

An evaluation of the capillus HIV-1/HIV-2 latex agglutination test using serum and whole blood.

The capillus HIV-1/HIV-2 latex agglutination (LA) test was evaluated for its potential as an initial screening test in primary health care. For the serum study, panels totalling 289 HIV-positive sera and 323 known HIV-negative sera plus 50 individual seroconversion samples were tested by capillus. Paired blood specimens were also collected in heparinized and plain tubes from 501 consecutive patients with newly diagnosed sexually transmitted diseases (STDs) attending an STD clinic at a Transvaal hospital. Overall, an initial sensitivity of 99.3% and an initial specificity of 99.7% were obtained by visual reading of the capillus HIV-1/ HIV-2 LA tests on serum samples. Capillus also detected 40 (80%) of the 50 seroconversion samples. Of the 501 paired plain and heparinized blood specimens, serum testing by enzyme immunoassay (EIA) and indirect immunofluorescence/ Western blot (IFA/WB) showed 147 (29%) to be HIV Ab positive. Capillus testing of the paired specimens correctly identified all 147 known positive patients and 345 of the 346 negative patients, thus showing an initial sensitivity of 100% and an initial specificity of 99.7% for the testing of heparinized whole blood by a relatively unskilled health worker. It was concluded that the capillus HIV-1/HIV-2 LA test would be suitable for use as a primary screening test in small outlying laboratories or primary health care clinics.

Polycystic ovarian syndrome. Evidence for an autoimmune mechanism in some cases.

Antiovarian autoantibodies localized to the granulosa cells were detected in 50% of a group of eight patients diagnosed with polycystic ovarian syndrome. An analogy is drawn to other endocrinopathies characterized by hypersecretion of hormones, notably thyroid and adrenal, and a pathogenetic mechanism involving stimulating antibody is postulated.

Cross-sectional and evolutive studies of schistosomiasis mansoni in untreated and mass treated endemic areas in the southeast and northeast of Brazil.

Cross-sectional and evolutive studies on schistosomiasis mansoni were carried out before and after mass treatment in the endemic areas of Capitão Andrade and Padre Paraiso, state of Minas Gerais, Riachuelo, state of Sergipe, Alhandra, state of Paraiba, and Aliança, Alegre and Coroatá, lowland of the state of Maranhão, Brazil, in the last eighteen years. The studies included clinical and fecal examination by the Kato-Katz quantitative technique, skin test for Schistosoma mansoni infection, evaluation of man-water contact and other epidemiological investigations such as infection rate and dynamic of the snail population. Results showed: (1) Higher prevalence of S. mansoni infection, greater egg load elimination and higher and earlier morbidity of the chronic forms of the disease in the southeast areas of Capitão Andrade and Padre Paraiso; (2) The incidence of hepatosplenic form is higher in some family clusters, in whites and mulattos in all the endemic areas but develop earlier in the southeast; (3) The prevalence and morbidity of schistosomiasis are decreasing both in the mass treated northeast and in the untreated southeast areas; (4) The mass treatment reduces rapidly the prevalence of the infection and the morbidity of the disease but can not control it because of the frequent reinfections due to the intensity of man-water contact.

[The effect of nifedipine on hemodynamics and gas exchange in dogs with experimental acute respiratory insufficiency]. / Ação da nifedipina na hemodinâmica e nas trocas gasosas em cães com insuficiência respiratória aguda experimental.

PURPOSE: Evaluate the action of nifedipine, a calcium channel blocking agent, on the hemodynamics and gas exchange experimental acute respiratory failure. METHODS: Lung injury was provoked in sixteen mongrel dogs with intratracheal instillation of hydrochloric acid (HC1) (0.1N; pH = 2.0; 2.0 ml/kg body weight). As steady state was achieved after HC1 instillation (maintenance of a stable arterial PO2), saline 1 ml (six dogs) or nifedipine (ten dogs) 30 micrograms/kg for body weight were intravenously injected. The hemodynamic variables and gas exchange parameters were analyzed before HC1, after HC1 and 10 and 30 minutes after nifedipine or saline. RESULTS: The intratracheal instillation of HC1 provoked significant drop of PaO2, of systemic oxygen transport index (ITO2S), and increase of venous admixture (QVA/Q). Nifedipine provoked significant reduction of the mean systemic arterial pressure (Pas), and of the systemic (IRVS) and pulmonary vascular resistance index (IRVP), with significant increase of cardiac (IC) and systolic index (IS), with no changes ot the mean arterial pulmonary (Pap) and capillary pressures (Pcap). After nifedipine there was a significant increase of PaO2, PvO2, and ITO2S, with no significant variations of QVA/Q and alveolar arterial O2 difference (P(A-a)O2). CONCLUSION: Nifedipine promoted systemic vasodilation, and probably by increasing the venous return and/or by a reflex mechanism, the cardiac output increased, augmenting the ITO2S. The IRVP decreased in the nifedipine group, with no significant alterations of Pap and Pcap, probably consequent to the systemic vasodilation provoked by the drug. The arterial PO2 augmented in the nifedipine group, as a consequence of mixed venous PO2 increase, since no changes occurred in QVA/Q, P(A-a)O2, inspired fraction of O2 and alveolar ventilation.

[The role of angiotensin-converting enzyme inhibitor (captopril) on the mechanism of hypoxic pulmonary vasoconstriction. Experimental study in dogs]. / Papel do inibidor da enzima conversora da angiotensina (captopril) no mecanismo da vasoconstricção pulmonar hipóxica. Estudo experimental em cães.

In order to evaluate the action of an angiotensin converting enzyme inhibitor (Captopril) on the pulmonary hypoxic vasoconstriction, twenty one mongrel dogs were studied in two groups: group I with hypoxia, group II with normoxia. The dogs were anesthetized, intubated, and had their femoral vein and artery cannulated for blood-gas sampling and pressure records. They were mechanically ventilated with hypoxic gas mixtures (12.3% O2-87.7% N2)--group I and room air group II, at random. In both groups we measured, before and after administration of captopril 3 mg/kg intravenously, gas exchange and hemodynamic variables, as well as plasmatic levels of renin and angiotensin converting enzymes (ACE). Our results showed that the group I dogs decreased the systemic and pulmonary vascular resistances with small changes in pulmonary arterial pressures and no significant variations of pulmonary systemic resistances ratio. There were no significant variations of the same variables in the group II dogs. The gas exchange has not changed in either group of animals. In the group I dogs Captopril provoked systemic and pulmonary vasodilatation, with no gasometric and ventilation/perfusion ratio changes. In our experimental model we could not conclude that Captopril inhibited the hypoxic pulmonary vasoconstriction and/or that the angiotensin II had some action on the hypoxic pulmonary vasoconstriction mechanism, but there are some evidences favoring that hypothesis.

[Hemodynamic and pulmonary effects of nifedipine]. / Efeito hemodinâmico sistêmico e pulmonar da nifedipina.

The authors reviewed the actions of nifedipine, a blocker of calcium channels, on the systemic and pulmonary circulation. The mechanism of action of the drug on the systemic and pulmonary circulation and on the gas exchange is discussed. The main effects of nifedipine on the coronary circulation and indications for therapeutic use of the drug are discussed on the topics of coronary insufficiency, systemic and pulmonary blood hypertension, acute respiratory failure, and Raynaud's phenomenon.

[Effects of captopril on hemodynamics, gas exchange and exercise capacity in patients with pulmonary hypertension secondary to chronic obstructive pulmonary disease]. / Efeitos do captopril na hemodinâmica, nas trocas gasosas e na capacidade de exercício em portadores de hipertensão pulmonar secundária a doença pulmonar obstrutiva crônica.

Captopril, a potent inhibitor of angiotensin converting enzyme, was tested in patients with COPD (means forced expired volume in the first second--FEV1 = 0.73 l) and pulmonary hypertension (PAP = 41.3 mmHg). In the first phase of the experiment, patients underwent and incremental exercise test to the limit of tolerance. These were double blind, randomized, cross-over studies, where the patients received oral placebo (Pl) or captopril (Cp) 25 mg, on different days. In a second phase, the patients were submitted to hemodynamic and gasometric studies in the supine position, before placebo, the 60 min after and immediately after exercise (cycling-like leg movements). After 30 min of rest the same protocol was repeated with oral administration of 25 mg of captopril. In the metabolic evaluation (cycloergometry) captopril increased significantly exercise tolerance (means VO2-uptake at maximal exercise: CP = 0.81 vs Pl = 0.73 1/min), associated with a slower heart rate and higher O2-pulse at maximal exercise. In the hemodynamic study, when the effects of Cp and Pl were compared, the mean values of pulmonary artery pressure (PAP) and pulmonary vascular resistance (PVR) were similar at rest, but significantly lower during exercise, after captopril (means PAP Cp = 41.3 vs Pl = 51.2 mmHg; XPVR Cp = 278 vs Pl = 392 dyn. sec. cm5). There were similar systemic hemodynamic effects after Cp, but these were more intense in the pulmonary circulation (lower PVR/SVR ratio post-Cp in relation to post-Pl, during exercise). The cardiac index, systemic O2 transport and arterial and mixed venous blood gases were similar at rest and during exercise, with Pl or Cp.(ABSTRACT TRUNCATED AT 250 WORDS)