Penetration of hydrogen peroxide and degradation rate of different bleaching products.

This study's aim was to evaluate the degradation rate of hydrogen peroxide (H2O2) and to quantify its penetration in tooth structure, considering the residence time of bleaching products on the dental enamel. For this study, bovine teeth were randomly divided according to the bleaching product received: Opalescence Xtra Boost 38%, White Gold Office 35%, Whiteness HP Blue 35%, Whiteness HP Maxx 35%, and Lase Peroxide Sensy 35%. To analyze the degradation of H2O2, the titration of bleaching agents with potassium permanganate was used, while the penetration of H2O2 was measured via spectrophotometric analysis of the acetate buffer solution, collected from the artificial pulp chamber. The analyses were performed immediately as well as 15 minutes, 30 minutes, and 45 minutes after product application. The data of degradation rate of H2O2 were submitted to analysis of variance (ANOVA) and Tukey tests, while ANOVA and Fisher tests were used for the quantification of H2O2, at the 5% level. The results showed that all products significantly reduced the concentration of H2O2 activates at the end of 45 minutes. It was also verified that the penetration of H2O2 was enhanced by increasing the residence time of the product on the tooth surface. It was concluded that the bleaching gels retained substantial concentrations of H2O2 after 45 minutes of application, and penetration of H2O2 in the dental structure is time-dependent.

Estudo de indicadores de prescrição, interações medicamentosas e classificação de risco ao feto em prescrições de gestantes da cidade de Mirassol - São Paulo. / Study of indicators of prescription, drug interactions and classification of risk to the fetus in pregnant requirements of the city of Mirassol - Sao Paulo

O uso racional de medicamentos é indispensável para garantir a qualidade e eficácia de um tratamento medicamentoso. Diante disto, a utilização de medicamentos durante a gestação deve ser analisada e acompanhada minuciosamente para minimizar os riscos e possíveis conseqüências ao feto e à gestante. Foram analisadas 100 receitas medicamentosas para gestantes, internadas no Hospital e Maternidade Mãe do Divino Amor na Providência de Deus do município de Mirassol, SP, utilizando os indicadores de prescrição propostos pela OMS, análise de interação medicamentosa por programas informatizados e pela literatura, classificação dos medicamentos encontrados segundo a classificação da segurança do fármaco durante a gravidez prescrita pelo Food and Drug Administration (FDA) a Relação Nacional de Medicamentos Essenciais (RENAME) e a Classificação Anatomical Therapeutic Chemical (ATC). Na análise dos indicadores de prescrição, nas 100 receitas avaliadas, encontrou-se a média de 2,6 medicamentos por prescrição; 21,5% de medicamentos prescritos pelo nome genérico; 40% delas contendo antibiótico; 59,4% com pelo menos um medicamento injetável e 58 % de medicamentos prescritos, presentes na Lista de Medicamentos Padronizados. Quanto à análise de interações medicamentosas, observa-se a prescrição do antibiótico cefalexina com o antiinflamatório cetoprofeno. Portanto, considerando-se os resultados obtidos no estudo e na revisão da literatura, sugere-se que as prescrições de medicamentos neste hospital para gestantes sejam melhor avaliadas segundo risco benefício, visando à minimização dos efeitos adversos desnecessários, tanto maternos como fetais.

The racional usage of medicines is indispensable to warrant the quality and efficacy of a medical treatment. Considering this, the use of remedies during pregnancy must be examined and followed in details to minimize the risks to the fetus and to the pregnant. A hundred of prescriptions to pregnant women interned at the Hospital Mãe do Divino Amor na Providência de Deus, in Mirassol city, São Paulo State, were analysed and compared with the prescription index designated by the WHO (World Health Organization). This work shows too the analysis of medicines interaction by softwares and literature and the classification of remedies by FDA (Food and Drug Administration) risk to the fetus, Rename (National List of Essential Medicines) and ATC (Anatomical Therapeutic Chemical). In one hundred of prescriptions analysed, there is a average of 2,6 medicines per precept, 21,5% of remedies prescribed by the generic name, 40% of indications of antibiotics, 59,4% of instructions with at least one medicine ministered by injection and 58 % of substances quoted in Remune (Municipal List of Essential Medicines). There was find only one interaction between the medicines: an antibiotic that belongs to the group of celafosporin and non-steroidal antiinflamatory. Thus, considering the results of the study and literature review, is suggested that the prescription of drugs in this hospital to betaken by the pregnantes be better assessed for risks and benefits, to minimize unnecessaru harm to the mother and the fetus.

Methacholine vs adenosine on intra and extrathoracic airway hyperresponsiveness in patients with cough variant asthma.

BACKGROUND: Airway hyperresponsiveness (AHR) can be studied by bronchoprovocation test (BPT) using direct (methacholine - MCh) or indirect (adenosine 5'-monophosphate - AMP) stimuli. These two substances have not been compared in cough variant asthma (CVA). OBJECTIVE: We designed a randomized, single-blind, cross-over study to compare AMP and MCh in the detection of CVA. Additionally, we examined whether assessment of extrathoracic airway hyperresponsiveness (EAHR) during MCh and AMP helped in the evaluation of CVA. METHODS: Patients with CVA with previous positive MCh BPT performed challenges with AMP and MCh. The variables were: (i) a provocative dose producing a 20% fall in forced expiratory volume in 1 s (FEV(1)) value (PD(20)MCh); (ii) a provocative dose producing a 25% fall in the maximal mid-inspiratory flow (FIF(50)) from baseline (PD(25)MCh) for MCh; (iii) a provocative concentration producing a 20% fall in FEV(1) value (PC(20)AMP) and (iv) a provocative concentration producing a 25% fall in the FIF(50) from baseline (PC(25)AMP) for AMP. RESULTS: All 113 patients with CVA responded to PD(20)MCh and 96% and 69% responded to PC(20)AMP, if we used PC(20)

Purification of a beta-galactosidase from cotyledons of Hymenaea courbaril L. (Leguminosae). Enzyme properties and biological function.

Beta-galactosidases are enzymes that can be found in most living beings and in the plant kingdom its activity and genes have been detected in several tissues such as ripening fruits, developing leaves and flowers and storage tissues such as cotyledons. In plants, their activities are usually associated with the secondary metabolism or with oligosaccharide or polysaccharide degradation. Polysaccharide specific beta-galactosidases include beta-galactanases, which attack pectic polymers and beta-galactosidases that attack xyloglucans (XG). In the present work we purified an XG-specific beta-galactosidase (named hcbetagal) from cotyledons of developing seedlings of Hymenaea courbaril, a legume tree from the Neotropical region of the world. The enzyme has a molecular weight of 52-62 kDa and was shown to attack specifically xyloglucan oligosaccharides (XGOs) but not the polymer. It has a pH optimum between 3 and 4 and at this pH range the enzyme increases activity linearly up to 50 degrees C. Kinetic studies showed that hcbetagal is inhibited competitively by free galactose (K(i) = 3.7). The biochemical properties of hcbetagal as a whole suggest that it is involved in storage xyloglucan mobilisation during seedling development. Its high specificity towards XGOs, the low pH optimum and the fact that it is inhibited by its product (galactose) suggest that hcbetagal might be one of the biochemical control points in xyloglucan catabolism in vivo. A possible relationship with functional stability of the wall during cell death as cotyledons undergo senescence is discussed.

A prospective longitudinal study of clinical characteristics, laboratory findings, diagnostic spectrum and outcomes of specific therapy in adult patients with chronic cough in a general respiratory clinic.

Chronic cough with established diagnostic protocols has been well described in secondary and tertiary centres. Little information is available about adult patients to a general respiratory clinic where no such protocols exist. The objective of this study is to determine clinical characteristics, laboratory findings, diagnostic spectrum and outcomes of specific therapy in adult patients with chronic cough in a general respiratory clinic. In this prospective, longitudinal, descriptive study for patients with chronic cough defined as more than 8 weeks, we studied, according to a questionnaire, chest radiography, spirometry and reversibility, methacholine challenge and other measures. Treatment was prescribed on the basis of diagnosis informed by investigation results.We evaluated 147 patients (102 females) of a mean age of 48 years and complaining of cough an average of 24 weeks. On the basis of a successful response to treatment, the causes of cough were determined in 92% and the frequencies were asthma in 39%, COPD in 11%, chronic upper airway cough syndrome (CUACS) in 9%, gastro-oesophageal reflux disease (GERD) in 9% and no diagnosis in 8%. Cough was due to one condition in 82%. Our treatment success rate was 92%. The most frequent causes of chronic cough (asthma, COPD, CUACS and GERD) could be determined in a general respiratory clinic with a sequential approach. The frequencies are different from those in a tertiary cough clinic, but outcome of specific therapy is successful in our patients.

Hereditary gingival fibromatosis: report of a five-generation family using cellular proliferation analysis.

BACKGROUND: Hereditary gingival fibromatosis (HGF) is an uncommon condition characterized by an accumulation of extracellular matrix resulting in a fibrotic enlargement of the gingiva. The goal of this article is to describe one kindred affected with HGF and discuss the diagnosis, treatment, and control of the disease. The pattern of inheritance, histopathologic characteristics, and proliferative potential of epithelial and mesenchymal cells of HGF are also emphasized. METHODS: To characterize the pattern of inheritance and the clinical appearance of gingival overgrowth, 117 family members were examined. The recurrence risk was estimated by the use of a genetic analysis program. Immunohistochemistry against the proliferating cell nuclear antigen (PCNA) and pKi-67 was performed to assess cellular proliferation of normal gingiva (NG) and HGF cells. RESULTS: Examination of the family pedigree demonstrated an autosomal dominant trait of inheritance, and a sibling recurrence risk of 0.085 and an offspring recurrence risk of 0.078, indicating that HGF was a consequence of genetic alteration with low penetrance. Unaffected and affected members transmitted the disease to their offspring. The affected patients showed a generalized but mild gingival overgrowth. Surgical treatment consisted of a combination of gingivectomy and gingivoplasty. Histologic examination showed that the gingival lesions of all patients were quite similar, with increased amounts of collagen fiber bundles in the connective tissue. Immunohistochemistry revealed that the proliferative potential of epithelial cells was significantly higher in the HGF group compared to the NG group, whereas mesenchymal cells from both groups were negative for the proliferative markers. CONCLUSION: Our data demonstrated that, in the studied family, HGF is transmitted by an autosomal dominant pattern with incomplete disease penetrance, and although the gingival enlargement resulted from an excessive accumulation of collagen fibers, HGF is characterized by an increase in the proliferation rate of epithelial cells.

Effects of long-term pretreatment with isoproterenol on inotropic responsiveness to alpha-adrenoceptor stimulation: study in isolated perfused rat hearts.

The effects of chronic pretreatment with isoproterenol (5 mg kg(-1)) daily for 10 days on cardiac alpha-adrenergic responsiveness in Langendorff heart preparations were investigated. Isoproterenol pretreatment caused cardiac hypertrophy (29%) as shown by a significant increase in the ratio of ventricular dry weight to body weight. In preparations from isoproterenol-pretreated rats, both maximum increases in left ventricular systolic pressure and heart rate elicited by isoproterenol (10(-12) to 10(-4) M) were significantly reduced (the isoproterenol concentration producing 50% of the maximum positive inotropic and chronotropic responses was enhanced almost 32- and 4-fold, respectively), while the positive inotropic response to phenylephrine (10(-12) to 10(-4) M) was significantly enhanced (the phenylephrine concentration producing 50% of the maximum positive inotropic effect was reduced almost 100-fold), compared with saline-pretreated rats. In preparations from both groups, phenylephrine infusion induced non-significant changes in heart rate and its positive inotropic response was reduced in the presence of propranolol (10(-7) M) in the perfusion medium. Even under beta-adrenoceptor blockade, the curve for the phenylephrine-induced positive inotropic effect remained shifted upward after isoproterenol pretreatment. Chronic isoproterenol pretreatment induces the expected cardiac beta-adrenoceptor desensitization while simultaneously enhancing the positive inotropic responsiveness to phenylephrine in Langendorff heart preparations. These findings support the hypothesis that cardiac alpha1-adrenoceptor stimulation may contribute to the maintenance of myocardial function under conditions in which beta-adrenoceptor function is compromised.

Comparison of spiramycin and clarithromycin for community-acquired lower respiratory tract infections.

This open multicentre study compared the efficacy and tolerability of clarithromycin and spiramycin in the treatment of lower respiratory tract infections in Brazil and Colombia. A total of 125 patients with a clinical and radiological diagnosis of pneumonia, acute bronchitis or exacerbation of chronic bronchitis were randomised to receive oral doses of either clarithromycin (500 mg) or spiramycin (3 MIU) every 12 hours for courses of 5-10 days. Patients were assessed before the start of treatment, and at days 3-4 and days 9-17. Twenty-six (26) patients (16 in the spiramycin group and 10 in the clarithromycin group) reported adverse events, seven of whom withdrew from the trial. Statistical analysis detected no significant differences between efficacy (p = 0.768) or tolerability (p = 0.236) for the two treatment groups. Spiramycin therefore has similar efficacy to clarithromycin in the treatment of community-acquired lower respiratory tract infections.

[Clinical and laboratory changes before the development of delirium tremens]. / Alterações clínicas e laboratoriais anteriores ao desenvolvimento do delirium tremens.

Thirteen alcoholic male patients that developed delirium tremens (DT) after admission in a psychiatric hospital for treatment of alcoholism (group I) had their clinical and laboratorial records examined. The laboratory samples were taken during the phase previous at the DT. Data on this group were compared to those of two other groups of alcoholics--26 patients each--that did not develop DT in the present admission, with (group II) or without (group III) previous history of DT. The patients of group I had significantly lower average age and worse general conditions than the patients of group III. The frequency of elevated aminotransferases and hypomagnesemia was significantly higher in the group I and II than in the group III. The aminotransferases, especially the aspartate-aminotransferase, were significantly more elevated in the groups I and II.

[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.

Correlation between arterial oxygen and carbon dioxide levels and response to almitrine bismesylate in normal dogs

The objectives of this study were: 1) to test the action of small doses of almitrine bismesylate (0.004 mg/Kg body weight/min) on the arterial blood gases and on pulmonary and systemic circulation during hypoventilation under controlled mechanical ventilation; and 2) to investigate possible correlations between arterial blood. O2 and CO3 levels and the response to the drug. Twenty one dogs divided into two groups were studied under controlled ventilation in a double-blind fashion: hypoventilation + placebo (HP) (seven dogs); hypoventilation + almitrine (HA) (fourteen dogs). The results showed no significant variations of the gas ex-change and hemodynamic varibles in the HP group. In the HP group, during almitrine bismesylate infusion, despite the lack of variation in the pulmonary ventilation, the PaO2 increased from 46.1 torr to 51.7 torr, the PaCO2 decreased from 61.9 torr to 57.7 torr. There were no significant variations of hemodynamic variables in the HA group. Thus we conclude that the drug improved arterial blood gases (PaO2 increased) with small increase in alveolar ventilation (PaCO2 decreased) despite the lack of changes in pulmonary ventilation, and that the drug has action on the arterial PO2 potentiated by hypoxemia and hypercapnia

Gas exchange during differential mechanical ventilation after unilateral lung injury induced by hydrochloric acid: experimental study in dogs

In order to test gas exchange in lungs with unilateral injury, when mechanical ventilation is needed, three groups (G-I, G-II, G-III) of seven dogs each were studied. Injury was induced in the left lung by injecting 0,lN, 1.0 ml per kg of body weight of hydrochloric acid, pH = 2.00. For groups I and II a conventional volumetric artificial ventilator was used. G-I was the control group. In group II a bilateral positive end-expiratory pressure (PEEP) was introduced during the last phase (phase 3) of the experiment, and in group III, a prototype of a volume cycled ventilator, with separated bellows, was used delivering tidal volumes separately to each lung through a Carlens' tube. In G-III, PEEP was introduced only to the injured lung in the last phase of the experiment. Phase l (Fl), basal phase, was similar in the three groups; phase 2 (F2) was the period after instillation of hydrochloric acid and phase 3 was the period after a 5 cmH2O bilateral PEEP was used in G-II, and a selective PEEP to the left lung was used in G-III. In each phase of the experiment, hemodynamic and gas exchange variables were obtained. Our results allowed the following conclusions: the differential lung ventilation technique maintained the alveolar ventilation of the dogs and the differential lung ventilation with unilateral PEEP was better for gas exchange (phase 3) than the conventional ventilation with bilateral PEEP (CPPB).