995 resultados para paepalatine 9 o beta dextro glucopyranoside


Relevância:

30.00% 30.00%

Publicador:

Resumo:

Purpose: To assess the correlation between MRI findings of the pancreas with those of the heart and liver in patients with beta thalassemia; to compare the pancreas T2* MRI results with glucose and ferritin levels and labile plasma iron (LPI). Materials and methods: We retrospectively evaluated chronically transfused patients, testing glucose with enzymatic tests, serum ferritin with chemiluminescence, LPI with cellular fluorescence, and T2* MRI to assess iron content in the heart, liver, and pancreas. MRI results were compared with one another and with serum glucose, ferritin, and LPI. Liver iron concentration (LIC) was determined in 11 patients' liver biopsies by atomic absorption spectrometry. Results: 289 MRI studies were available from 115 patients during the period studied. 9.4% of patients had overt diabetes and an additional 16% of patients had impaired fasting glucose. Both pancreatic and cardiac R2* had predictive power (p < 0.0001) for identifying diabetes. Cardiac and pancreatic R2* were modestly correlated with one another (r(2) = 0.20, p < 0.0001). Both were weakly correlated with LIC (r(2) = 0.09, p < 0.0001 for both) and serum ferritin (r(2) = 0.14, p < 0.0001 and r(2) = 0.03, p < 0.02, respectively). None of the three served as a screening tool for single observations. There is a strong log-log, or power-law, relationship between ratio of signal intensity (SIR) values and pancreas R2* with an r(2) of 0.91. Conclusions: Pancreatic iron overload can be assessed by MRI, but siderosis in other organs did not correlate significantly with pancreatic hemosiderosis. (C) 2011 Elsevier Ireland Ltd. All rights reserved.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Background: Equations to predict maximum heart rate (HRmax) in heart failure (HF) patients receiving beta-adrenergic blocking (BB) agents do not consider the cause of HF. We determined equations to predict HRmax in patients with ischemic and nonischemic HF receiving BB therapy. Methods and Results: Using treadmill cardiopulmonary exercise testing, we studied HF patients receiving BB therapy being considered for transplantation from 1999 to 2010. Exclusions were pacemaker and/or implantable defibrillator, left ventricle ejection fraction (LVEF) >50%, peak respiratory exchange ratio (RER) <1.00, and Chagas disease. We used linear regression equations to predict HRmax based on age in ischemic and nonischemic patients. We analyzed 278 patients, aged 47 +/- 10 years, with ischemic (n = 75) and nonischemic (n = 203) HF. LVEF was 30.8 +/- 9.4% and 28.6 +/- 8.2% (P = .04), peak VO2 16.9 +/- 4.7 and 16.9 +/- 5.2 mL kg(-1) min(-1) (P = NS), and the HRmax 130.8 +/- 23.3 and 125.3 +/- 25.3 beats/min (P = .051) in ischemic and nonischemic patients, respectively. We devised the equation HRmax = 168 - 0.76 x age (R-2 = 0.095; P = .007) for ischemic HF patients, but there was no significant relationship between age and HRmax in nonischemic HF patients (R-2 = 0.006; P = NS). Conclusions: Our study suggests that equations to estimate HRmax should consider the cause of HF. (J Cardiac Fail 2012;18:831-836)

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Human Parvovirus B19 (B19V) is a recognized cause of life-threatening conditions among patients with hemoglobinopathies. This study investigates B19V infection in patients with sickle cell disease and beta-thalassemia using different experimental approaches. A total of 183 individuals (144 with sickle cell disease and 39 with beta-thalassemia major) and 100 healthy blood donors were examined for B19V using anti-B19V IgG enzyme immunoassay, quantitative PCR, DNA sequencing, and phylogenetic analysis. Viremia was documented in 18.6% of patients and 1% of donors, and was generally characterized by low viral load (VL); however, acute infections were also observed. Anti-B19V IgG was detected in 65.9% of patients with sickle cell disease and in 60% of donors, whereas the patients with thalassemia exhibited relatively low seroreactivity. The seroprevalence varied among the different age groups. In patients, it progressively increased with age, whereas in donors it reached a plateau. Based on partial NS1 fragments, all isolates detected were classified as subgenotype 1A with a tendency to elicit genetically complex infections. Interestingly, quasispecies occurred in the plasma of not only patients but also donors with even higher heterogeneity. The partial NS1 sequence examined did not exhibit positive selection. Quantitation of B19V with a conservative probe is a technically and practically useful approach. The extensive spread of B19V subgenotype 1A in patients and donors and its recent introduction into the countryside of the Sao Paulo State, Brazil were demonstrated; however, it is difficult to establish a relationship between viral sequences and the clinical outcomes of the infection. J. Med. Virol. 84:16521665, 2012. (c) 2012 Wiley Periodicals, Inc.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Skeletal muscles from old rats fail to completely regenerate following injury. This study investigated whether pharmacological stimulation of beta 2-adrenoceptors in aged muscles following injury could improve their regenerative capacity, focusing on myofiber size recovery. Young and aged rats were treated with a subcutaneous injection of beta 2-adrenergic agonist formoterol (2 mu g/kg/d) up to 10 and 21 days after soleus muscle injury. Formoterol-treated muscles from old rats evaluated at 10 and 21 days postinjury showed reduced inflammation and connective tissue but a similar number of regenerating myofibers of greater caliber when compared with their injured controls. Formoterol minimized the decrease in tetanic force and increased protein synthesis and mammalian target of rapamycin phosphorylation in old muscles at 10 days postinjury. Our results suggest that formoterol improves structural and functional regenerative capacity of regenerating skeletal muscles from aged rats by increasing protein synthesis via mammalian target of rapamycin activation. Furthermore, formoterol may have therapeutic benefits in recovery following muscle damage in senescent individuals.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Background: Metastasis is the main factor responsible for death in breast cancer patients. Matrix metalloproteinases (MMPs) and their inhibitors, known as tissue inhibitors of MMPs (TIMPs), and the membrane-associated MMP inhibitor (RECK), are essential for the metastatic process. We have previously shown a positive correlation between MMPs and their inhibitors expression during breast cancer progression; however, the molecular mechanisms underlying this coordinate regulation remain unknown. In this report, we investigated whether TGF-beta 1 could be a common regulator for MMPs, TIMPs and RECK in human breast cancer cell models. Methods: The mRNA expression levels of TGF-beta isoforms and their receptors were analyzed by qRT-PCR in a panel of five human breast cancer cell lines displaying different degrees of invasiveness and metastatic potential. The highly invasive MDA-MB-231 cell line was treated with different concentrations of recombinant TGF-beta 1 and also with pharmacological inhibitors of p38 MAPK and ERK1/2. The migratory and invasive potential of these treated cells were examined in vitro by transwell assays. Results: In general, TGF-beta 2, T beta RI and T beta RII are over-expressed in more aggressive cells, except for T beta RI, which was also highly expressed in ZR-75-1 cells. In addition, TGF-beta 1-treated MDA-MB-231 cells presented significantly increased mRNA expression of MMP-2, MMP-9, MMP-14, TIMP-2 and RECK. TGF-beta 1 also increased TIMP-2, MMP-2 and MMP-9 protein levels but downregulated RECK expression. Furthermore, we analyzed the involvement of p38 MAPK and ERK1/2, representing two well established Smad-independent pathways, in the proposed mechanism. Inhibition of p38MAPK blocked TGF-beta 1-increased mRNA expression of all MMPs and MMP inhibitors analyzed, and prevented TGF-beta 1 upregulation of TIMP-2 and MMP-2 proteins. Moreover, ERK1/2 inhibition increased RECK and prevented the TGF-beta 1 induction of pro-MMP-9 and TIMP-2 proteins. TGF-beta 1-enhanced migration and invasion capacities were blocked by p38MAPK, ERK1/2 and MMP inhibitors. Conclusion: Altogether, our results support that TGF-beta 1 modulates the mRNA and protein levels of MMPs (MMP-2 and MMP-9) as much as their inhibitors (TIMP-2 and RECK). Therefore, this cytokine plays a crucial role in breast cancer progression by modulating key elements of ECM homeostasis control. Thus, although the complexity of this signaling network, TGF-beta 1 still remains a promising target for breast cancer treatment.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The synthesis and photoluminescent properties of Ln(III)-thenoyltrifluoroacetonate and dibenzoylmethanate complexes (Ln = Eu(III) and Gd(III) ions) containing tertiary amides such as dimethylacetamide (DMA), dimethylformamide (DMF), and dimethylbenzamide (DMB) as neutral ligands are reported. The Ln complexes were characterized by elemental analysis, complexometric titration with EDTA, and infrared spectroscopy. Single-crystal X-ray structure data of the [Eu(DBM)(3).(DMA)] compound indicates that this complex crystallizes in the triclinic system, space group PT with the following cell parameters: a = 10.2580(3) angstrom, b = 10.3843(2) angstrom, c= 22.3517(5) angstrom, alpha = 78.906(2)degrees, beta = 78.049(2)degrees, lambda= 63.239(2)degrees, V= 2066.41(9) angstrom(3), and Z = 2. The coordination polyhedron for the Eu(III) complex may be described as an approximate C-2v distorted monocapped trigonal prism. The optical properties of the Eu(III) complexes were studied based on the intensity parameters and luminescence quantum yield (q). The values of the ohm(2) parameter of the Eu-DBM complexes are larger than those for the Eu-TTA complexes, indicating that the Eu(III) ion is in a more polarizable chemical environment in the former case. The geometries of the complexes have been optimized by using the Sparkle Model, and the results have been used to perform theoretical predictions of the ligand-to-metal energy transfer via direct and exchange Coulomb mechanisms. (C) 2012 Elsevier Ltd. All rights reserved.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

BACKGROUND AND PURPOSE The bed nucleus of the stria terminalis (BNST) is a limbic structure that is involved in the expression of conditioned contextual fear. Among the numerous neural inputs to the BNST, noradrenergic synaptic terminals are prominent and some evidence suggests an activation of this noradrenergic neurotransmission in the BNST during aversive situations. Here, we have investigated the involvement of the BNST noradrenergic system in the modulation of behavioural and autonomic responses induced by conditioned contextual fear in rats. EXPERIMENTAL APPROACH Male Wistar rats with cannulae bilaterally implanted into the BNST were submitted to a 10 min conditioning session (6 footshocks, 1.5 ma/ 3 s). Twenty-four hours later freezing and autonomic responses (mean arterial pressure, heart rate and cutaneous temperature) to the conditioning box were measured for 10 min. The adrenoceptor antagonists were administered 10 min before the re-exposure to the aversive context. KEY RESULTS L-propranolol, a non-selective beta-adrenoceptor antagonist, and phentolamine, a non-selective a-adrenoceptor antagonist, reduced both freezing and autonomic responses induced by aversive context. Similar results were observed with CGP20712, a selective beta 1-adrenoceptor antagonist, and WB4101, a selective a1-antagonist, but not with ICI118,551, a selective beta 2-adrenoceptor antagonist or RX821002, a selective a2-antagonist. CONCLUSIONS AND IMPLICATIONS These findings support the idea that noradrenergic neurotransmission in the BNST via a1- and beta 1-adrenoceptors is involved in the expression of conditioned contextual fear.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The aim of this study was to investigate the expression of vascular endothelial growth factor type C (VEGF-C) in oral squamous cell carcinoma (OSCC) cell lines through norepinephrine-induced activation of beta-adrenergic receptors. Human OSCC cell lines (SCC-9 and SCC-25) expressing beta-adrenergic receptors were stimulated with different concentrations of norepinephrine (0.1, 1, and 10 μM) and 1 μMof propranolol, and analyzed after 1, 6, and 24 h. VEGF-C gene expression and VEGF-C production in the cell supernatant were evaluated by real-time PCR and by ELISA, respectively. The results showed that beta-adrenergic receptor stimulation by different concentrations of norepinephrine or blocking by propranolol did not markedly alter VEGF-C expression by SCC-9 and SCC-25 cells. VEGF-C protein levels produced by oral malignant cell lines after stimulation with different norepinephrine concentrations or blocking with propranolol was statistically similar (p>0.05) to those of the control group (nonstimulated OSCC cell lines). Our findings suggest that stimulation of beta-adrenergic receptors by means of norepinephrine does not seem to modulate the VEGF-C expression in OSCC cell lines. These findings reinforce the need for further studies in order to understand the responsiveness of oral cancer to beta-adrenergic receptor stimulation or blockage, especially with regard to VEGF-C production.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Abstract Background Melatonin is associated with direct or indirect actions upon female reproductive function. However, its effects on sex hormones and steroid receptors during ovulation are not clearly defined. This study aimed to verify whether exposure to long-term melatonin is able to cause reproductive hormonal disturbances as well as their role on sex steroid receptors in the rat ovary, oviduct and uterus during ovulation. Methods Twenty-four adult Wistar rats, 60 days old (+/- 250 g) were randomly divided into two groups. Control group (Co): received 0.9% NaCl 0.3 mL + 95% ethanol 0.04 mL as vehicle; Melatonin-treated group (MEL): received vehicle + melatonin [100 μg/100 g BW/day] both intraperitoneally during 60 days. All animals were euthanized by decapitation during the morning estrus at 4 a.m. Results Melatonin significantly reduced the plasma levels of LH and 17 beta-estradiol, while urinary 6-sulfatoximelatonin (STM) was increased at the morning estrus. In addition, melatonin promoted differential regulation of the estrogen receptor (ER), progesterone receptor (PR), androgen receptor (AR) and melatonin receptor (MTR) along the reproductive tissues. In ovary, melatonin induced a down-regulation of ER-alpha and PRB levels. Conversely, it was observed that PRA and MT1R were up-regulated. In oviduct, AR and ER-alpha levels were down-regulated, in contrast to high expression of both PRA and PRB. Finally, the ER-beta and PRB levels were down-regulated in uterus tissue and only MT1R was up-regulated. Conclusions We suggest that melatonin partially suppress the hypothalamus-pituitary-ovarian axis, in addition, it induces differential regulation of sex steroid receptors in the ovary, oviduct and uterus during ovulation.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Background: Variations in maternal care are associated with neonatal stress, hormonal disturbances and reproductive injuries during adulthood. However, the effects of these variations on sex hormones and steroid receptors during ovary development remain undetermined. This study aimed to investigate whether variations in maternal care are able to influence the hormonal profile, follicular dynamics and expression of AR, ER-alpha and ER-beta in the ovaries of UCh rat offspring. Methods: Twenty-four adult UCh rats, aged 120 days, were randomly divided into two groups (UChA and UChB) and mated. Maternal care was assessed from birth (day 0) to the 10th postnatal day (PND). In adulthood, twenty adult female rats (UChA and UChB offspring; n = 10/group), aged 120 days, were euthanized by decapitation during the morning estrus. Results: UChA females (providing high maternal care) more frequently displayed the behaviors of carrying pups, as well as licking/grooming and arched back nursing cares. Also, mothers providing high care had elevated corticosterone levels. Additionally, offspring receiving low maternal care showed the highest estrous cycle duration, increased corticosterone and 17beta-estradiol levels, overexpression of receptors ER-alpha and ER-beta, increased numbers of primordial, antral and mature follicles and accentuated granulosa cell proliferation. Conclusions: Our study suggests that low maternal care alters corticosterone and 17beta-estradiol levels, disrupting the estrous cycle and folliculogenesis and differentially regulating the expression of ER-alpha and ER-beta in the ovaries of adult rats.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

OBJECTIVE: Chagas' disease has spread throughout Latin America because of the high rate of migration among these countries. Approximately 30% of Chagas' patients will develop cardiomyopathy, and 10% of these will develop severe cardiac damage leading to heart failure. Beta-blockade improves symptoms and survival in heart failure patients; however, its efficacy has not been well established in Chagas' disease. We evaluated the role of carvedilol in cardiac remodeling and mortality in a Chagas' cardiomyopathy animal model. METHODS: We studied Trypanosoma cruzi infection in 55 Syrian hamsters that were divided into three groups: control (15), infected (20), and infected + carvedilol (20). Animals underwent echocardiography, electrocardiography, and morphometry for collagen evaluation in ventricles stained with picrosirius red. RESULTS: The left ventricular diastolic diameter did not change between groups, although it was slightly larger in infected groups, as was left ventricular systolic diameter. Fractional shortening also did not change between groups, although it was slightly lower in infected groups. Collagen accumulation in the interstitial myocardial space was significantly higher in infected groups and was not attenuated by carvedilol. The same response was observed in the perivascular space. The survival curve showed significantly better survival in the control group compared with the infected groups; but no benefit of carvedilol was observed during the study. However, in the acute phase (up to 100 days of infection), carvedilol did reduce mortality. CONCLUSION: Carvedilol did not attenuate cardiac remodeling or mortality in this model of Chagas' cardiomyopathy. The treatment did improve survival in the acute phase of the disease.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The aim of the present study was to examine the association between milk protein polymorphism and fatty acids profiles of bovine milk. Milk samples were collected from each of 55 Reggiana cows during early, mid and late lactation, respectively, in two farms within the production area of Parmigiano Reggiano cheese. Identification and quantification of fatty acids were performed by gas chromatography. Milk fatty acid composition using cows of differing κ-casein (κ-Cn) and β-lactoglobulin (β-Lg) phenotypes was investigated. Statistically significant results regarding the associations between milk fatty acid composition and κ-Cn phenotype were found, in particular, κ-Cn BB seems to influence de novo fatty acid synthesis in the mammary gland. Also κ-Cn AB seems to have the same effect. Proportions of C10:0 (2,29a AA; 2,53b AB; 2,59b BB), C12:0 (2,77a AA; 3,17b AB; 3,20b BB) and C14:0 (9,22a AA; 10,25b AB; 10,27b BB) were higher in the milk from cows with κ-Cn phenotype AB and BB vs κ-Cn phenotype AA (p<0,05). Conversely C18:0 (7,84b AA; 7,20a,b AB; 6,94a BB) and C18:1 (19,19b AA; 16,81a AB; 16,79a BB) were lower in the milk from cows with κ-Cn phenotype AB and BB vs κ-Cn phenotype AA. The association between milk fatty acid composition and β-Lg phenotype was not statistically significant, except for some fatty acids. In particular, C12:0 (3,05a AA; 3,04a AB; 3,33b BB) was higher in the milk from cows with β-Lg phenotype BB vs β-Lg phenotype AA and AB (p<0,05). Concentrations of C18:0 (6,93a AA; 7,86b AB; 6,59a BB) and C18:1 (16,74a,b AA; 18,24b AB; 16,07a BB) were lower in the milk from cows with β-Lg phenotype AA and BB vs β-Lg phenotype AB (p<0,05). Moreover this research, carried out in farms within the Parmigiano Reggiano cheese district, analysed also the size distribution of fat globules in bulk milk of Reggiana and Frisona breed cows. In particular, the size distribution of individual milk fat globules of Reggiana cows with differing κ-Cn phenotypes was considered. From first observations, no statistically significant differences were observed.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Basal-like tumor is an aggressive breast carcinoma subtype that displays an expression signature similar to that of the basal/myoepithelial cells of the breast tissue. Basal-like carcinoma are characterized by over-expression of the Epidermal Growth Factor receptor (EGFR), high frequency of p53 mutations, cytoplasmic/nuclear localization of beta-catenin, overexpression of the Hypoxia inducible factor (HIF)-1alpha target Carbonic Anhydrase isoenzime 9 (CA9) and a gene expression pattern similar to that of normal and cancer stem cells, including the over-expression of the mammary stem cell markers CD44. In this study we investigated the role of p53, EGFR, beta-catenin and HIF-1alpha in the regulation of stem cell features and genes associated with the basal-like gene expression profile. The findings reported in this investigation indicate that p53 inactivation in ductal breast carcinoma cells leads to increased EGFR mRNA and protein levels. In our experimental model, EGFR overexpression induces beta-catenin cytoplasmatic stabilization and transcriptional activity and, by that, leads to increased aggressive features including mammosphere (MS) forming and growth capacity, invasive potential and overexpression of the mammary stem cell gene CD44. Moreover we found that EGFR/beta-catenin axis promotes hypoxia survival in breast carcinoma cells via increased CA9 expression. Indeed beta-catenin positively regulates CA9 expression upon hypoxia exposure. Interestingly we found that beta-catenin inhibits HIF-1alpha transcriptional activity. Looking for the mechanism, we found that CA9 expression is promoted by HIF-1alpha and cytoplasmatic beta-catenin further increased it post-transcriptionally, via direct mRNA binding and stabilization. These data reveal a functional beta-catenin/HIF-1alpha interplay among hallmarks of basal-like tumors and unveil a new functional role for cytoplasmic beta-catenin in the phenotype of such tumors. Therefore it can be proposed that the interplay here described among EGFR/beta-catenin and HIF-1alpha may play a role in breast cancer stem cell survival and function.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

BACKGROUND: The aim of the study is to clinically and histologically evaluate the healing of advanced intrabony defects treated with open flap debridement and the adjunct implantation of granular beta tricalcium phosphate (beta-TCP). METHODS: Five patients, each displaying advanced combined 1- and 2-wall intrabony defects around teeth scheduled for extraction or root resection, were recruited. Approximately 6 months after surgery, the teeth or roots were removed together with a portion of their surrounding soft and hard tissues and processed for histologic evaluation. RESULTS: The mean probing depth (PD) was reduced from 10.8 +/- 2.3 mm presurgically to 4.6 +/- 2.1 mm, whereas a mean clinical attachment level (CAL) gain of 5.0 +/- 0.7 mm was observed. The increase in gingival recession was 1.2 +/- 3.2 mm. The histologic evaluation indicated the formation of new cellular cementum with inserting collagen fibers to a varying extent (mean: 1.9 +/- 0.7 mm; range: 1.2 to 3.03 mm) coronal to the most apical extent of the root instrumentation. The mean new bone formation was 1.0 +/- 0.7 mm (range: 0.0 to 1.9 mm). In most specimens, beta-TCP particles were embedded in the connective tissue, whereas the formation of a mineralized bone-like or cementum-like tissue around the particles was only occasionally observed. CONCLUSION: The present data indicates that treatment of intrabony periodontal defects with this beta-TCP may result in substantial clinical improvements such as PD reduction and CAL gain, but this beta-TCP does not seem to enhance the regeneration of cementum, periodontal ligament, and bone.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Amyloid precursor protein (APP) and amyloid-beta (Abeta) appear to participate in the pathophysiology of retinal ganglion cell (RGC) death in glaucoma. We, therefore, determined the distribution of APP and Abeta in the retinas of C57BL/6 mice after induction of chronic ocular hypertension.