TNF-alpha Knockout Mice Have Increased Corpora Cavernosa Relaxation

Erectile dysfunction is considered an early clinical manifestation of vascular disease and an independent risk factor for cardiovascular events associated with endothelial dysfunction and increased levels of pro-inflammatory cytokines. Tumor necrosis factor-alpha (TNF-alpha), a pro-inflammatory cytokine, suppresses endothelial nitric oxide synthase (eNOS) expression. Considering that nitric oxide (NO) is of critical importance in penile erection, we hypothesized that blockade of TNF-alpha actions would increase cavernosal smooth muscle relaxation. In vitro organ bath studies were used to measure cavernosal reactivity in wild type and TNF-alpha knockout (TNF-alpha KO) mice and NOS expression was evaluated by western blot. In addition, spontaneous erections (in vivo) were evaluated by videomonitoring the animals (30 minutes). Collagen and elastin expression were evaluated by Masson trichrome and Verhoff-van Gieson stain reaction, respectively. Corpora cavernosa from TNF-alpha KO mice exhibited increased NO-dependent relaxation, which was associated with increased eNOS and neuronal NOS (nNOS) cavernosal expression. Cavernosal strips from TNF-alpha KO mice displayed increased endothelium-dependent (97.4 +/- 5.3 vs. Control: 76.3 +/- 6.3, %) and nonadrenergic-noncholinergic (93.3 +/- 3.0 vs. Control: 67.5 +/- 16.0; 16 Hz) relaxation compared to control animals. These responses were associated with increased protein expression of eNOS and nNOS (P < 0.05). Sympathetic-mediated (0.69 +/- 0.16 vs. Control: 1.22 +/- 0.22; 16 Hz) as well as phenylephrine-induced contractile responses (1.6 +/- 0.1 vs. Control: 2.5 +/- 0.1, mN) were attenuated in cavernosal strips from TNF-alpha KO mice. Additionally, corpora cavernosa from TNF-alpha KO mice displayed increased collagen and elastin expression. In vivo experiments demonstrated that TNF-alpha KO mice display increased number of spontaneous erections. Corpora cavernosa from TNF-alpha KO mice display alterations that favor penile tumescence, indicating that TNF-alpha plays a detrimental role in erectile function. A key role for TNF-alpha in mediating endothelial dysfunction in ED is markedly relevant since we now have access to anti-TNF-alpha therapies. Carneiro FS, Sturgis LC, Giachini FRC, Carneiro ZN, Lima VV, Wynne BM, Martin SS, Brands MW, Tostes RC, and Webb RC. TNF-alpha knockout mice have increased corpora cavernosa relaxation. J Sex Med 2009;6:115-125.

Effects of Ipratropium on Exercise-Induced Bronchospasm

Exercise-induced bronchospasm (EIB) is the transient narrowing of the airways that follows vigorous exercise. Ipratropium bromide may be used to prevent EIB, but its effect varies among individuals. We hypothesized that time of administration of ipratropium interferes with its action. This was a prospective, double-blind, cross-over study carried out to evaluate the bronchoprotective and bronchodilatory effect of ipratropium at different times of day. The study consisted of 4 exercise challenge tests (2 at 7 am and 2 at 6 pm). In the morning, one of the tests was performed after placebo administration and the other one after ipratropium (80 mu g) and the two tests (placebo and ipratropium) were repeated in the evening. Twenty-one patients with severe or moderate asthma and previous confirmation of EIB were enrolled in this prospective trial. The bronchodilatory effect of ipratropium was 0.25 +/- 0.21 L or 13.11 +/- 10.99 % (p = 0.001 compared to baseline values) in the morning, and 0.14 +/- 0.25 L or 7.25 +/- 11.37 % (p > 0.05) in the evening. In the morning, EIB was 0.58 +/- 0.29 L on the placebo day and 0.38 +/- 0.22 L on the treatment day (p = 0.01). In the evening, EIB was 0.62 +/- 0.28 L on the placebo day and 0.51 +/- 0.35 L on the treatment day (p > 0.05). We suggest that the use of ipratropium for the treatment of asthma and EIB should take into consideration the time of administration.

Chronic alcoholism associated with diabetes impairs erectile function in rats

OBJECTIVE To investigate the effects of chronic ethanol consumption and diabetes on nitric oxide (NO)-mediated relaxation of cavernosal smooth muscle (CSM). MATERIAL AND METHODS Male Wistar rats were divided into four groups: control, isocaloric, diabetic and ethanol-diabetic. The CSMs were mounted in organ chambers for measurement of isometric tension. Contraction of the strips was induced by electrical field stimulation (EFS, 1-32 Hz) and phenylephrine. We also evaluated the effect of ethanol consumption on the relaxation induced by acetylcholine (ACh; 0.01-1000 mu mol/L), sodium nitroprusside (SNP, 0.01-1000 mu mol/L) or EFS (1-32 Hz) in strips pre-contracted with phenylephrine (10 mu mol/L). Immunoexpression of endothelial NO synthase (eNOS) and inducible NOS (iNOS) was also accessed. RESULTS The endothelium-dependent relaxation induced by ACh was decreased in CSM from ethanol-diabetic rats when compared with the controls, with a mean (sem) of 21 (4) vs 37 (2)%. Similarly, the potency and maximal responses induced by SNP were reduced in the ethanol-diabetic [3.97 (0.38) and 85 (1)%, respectively] and diabetic groups [3.78 (0.56) and 81 (2)%, respectively] when compared with the controls [5.3 (0.22) and 90 (3)%, respectively] and isocaloric [5.3 (0.19) and 92 (1)%, respectively] groups. Noradrenergic nerve-mediated contractions of CSM in response to EFS were increased in rats from ethanol-diabetic and diabetic groups when compared with the control and isocaloric groups. Conversely, there were no differences in EFS-induced relaxation among the groups. The immunostaining assays showed overexpression of eNOS and iNOS in the CSM from diabetic and ethanol-diabetic rats when compared with the control and isocaloric rats. CONCLUSION There was an impairment of relaxation of CSM from ethanol-diabetic and diabetic rats that involved a decrease in the NO-cyclic guanosine monophosphate signalling pathway by endothelium-dependent mechanisms accompanied by a change in the CSM contractile sensitivity.

Preventive effect of iron gel with or without fluoride on bovine enamel erosion in vitro

Background: The aim of this study was to evaluate the preventive effect in vitro of experimental gel containing iron and/or fluoride on the erosion of bovine enamel. Methods: To standardize the blocks (n = 80), specimens (4 x 4 mm) were previously selected to measure the initial microhardness. The blocks were randomly allocated into four groups of 20 samples each: C (control, placebo gel); F (fluoride gel, 1.23% NaF); Fe (iron gel, 10 mmol/L FeSO(4)) and F + Fe (fluoride + iron gel). The gels were applied and removed after 1 minute. The blocks were then submitted to six alternating remineralization and demineralization cycles. The beverage Coca-Cola (R) (10 minutes, 30 mL) was used for demineralization, and artificial saliva (1 hour) for remineralization. The effect of erosion was measured by wear analysis (profilometry). Data were analysed by ANOVA and the Tukey test for individual comparisons (p <0.05). Results: The mean wear (+/- SD, mu m) was C: 0.94 +/- 0.22; F: 0.55 +/- 0.12; Fe: 0.49 +/- 0.11 and F + Fe: 0.55 +/- 0.13. When the experimental gels were used, there was statistically significant reduction in enamel wear in comparison with the control (p <0.001). However, the experimental gels did not differ significantly among them. Conclusions: The gels containing iron with or without fluoride are capable of interfering with the dissolution dental enamel in the presence of erosive challenge.

Evaluation of physicochemical properties of four root canal sealers

P>Aim To assess the physicochemical properties and the surface morphology of AH Plus, GuttaFlow, RoekoSeal and Activ GP root canal sealers. Methodology Five samples of each material were evaluated for setting time, dimensional alteration, solubility and radiopacity tests, according to ANSI/ADA Specification 57. A total of 50 mL of deionized distilled water from the solubility tests were used to measure the metal solubility by atomic absorption spectrometry. The morphologies of the external surface and the cross-section of the samples were analysed by means of a scanning electron microscope (SEM). Statistical analysis was performed by using one-way anova and post hoc Tukey-Kramer tests with the null hypothesis set as 5%. Results AH Plus had the longest setting time (580.6 +/- 3.05 min) (P < 0.05). Activ GP did not have a mean value on the radiopacity and solubility tests (1.31 +/- 0.35 mm and 11.8 +/- 0.43%, respectively) in accordance with ANSI/ADA, being significantly different from the other materials (P < 0.05), which had mean values for these tests in accordance with the ADA`s requirements. GuttaFlow was the only sealer that conformed to the Specification 57 concerning the dimensional alteration test (0.44 +/- 0.16%) (P < 0.05). The spectrometry test revealed significant Ca2+, K+, Zn2+ ion release from Activ GP sealer (32.57 +/- 5.0, 1.57 +/- 0.22 and 8.20 +/- 1.74 mu g mL-1, respectively). In SEM analysis, the loss of matrix was evident and the filler particles were more distinguishable in all groups. Conclusions The setting time of all sealers was in accordance with ANSI/ADA`s requirements. Activ GP did not fulfill ANSI/ADA`s protocols regarding radiopacity, dimensional alteration and solubility. GuttaFlow was the only sealer that conformed to the Specification 57 in all tests. SEM analysis revealed that the surfaces of all sealers had micromorphological changes after the solubility test.