48 resultados para RESISTANT


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The protein affected in Menkes disease, ATP7A, is a copper (Cu)-transporting P-type ATPase that plays an important role in Cu homeostasis, but the full extent of this role has not been defined at a systemic level. Transgenic mice that overexpress the human ATP7A from the chicken β-actin composite promoter (CAG) were used to further investigate the physiological function of ATP7A. Overexpression of ATP7A in the mice caused disturbances in Cu homeostasis, with depletion of Cu in some tissues, especially the heart. To investigate the effect of overexpression of ATP7A when dietary Cu intake was markedly increased, normal and transgenic mice were exposed to drinking water containing 300 mg/L of Cu as Cu acetate for 3 mo. Cu exposure resulted in partial restoration of heart Cu concentrations in male transgenic mice. Despite the extended period of Cu exposure, Cu concentrations in the liver remained relatively unaffected, with a significant increase in male nontransgenic mice. Liver pathology was unremarkable except for small areas of fibrosis that were detected only in livers of the Cu-exposed transgenic mice. Intracellular localization of ATP7A in various tissues was not affected by Cu exposure. Plasma Cu concentration and ceruloplasmin oxidase activity were reduced in both Cu-exposed transgenic and nontransgenic mice. The expression levels of other candidate Cu homeostatic proteins, endogenous Atp7b, ceruloplasmin, Ctr1, and transgenic ATP7A were not altered significantly by Cu exposure. Overall, mice are remarkably resistant to high Cu loads and the overexpression of ATP7A has only moderate effects on the response to Cu exposure. © 2008 American Society for Nutrition.

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 The objective of this investigation was to set down (on the base of the results obtained by the examination of white cast iron alloys with different content of the alloying elements) a correlation between chemical composition and microstructure, on one hand, and the properties relevant for this group of materials, i.e., abrasion wear resistance and fracture toughness, on the other. Experimental results indicate that the volume fracture of the carbide phase, carbide size and distribution, as well as the morphology of eutectic colonies, had an important influence on the wear resistance of white cast iron alloys under low-stress abrasion conditions, whereas fracture toughness was determined largely by the matrix microstructure.

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We determined the effect of an acute bout of swimming (8 × 30 min) followed by either carbohydrate administration (0.5 mg/g glucose ip and ad libitum access to chow; CHO) or fasting (Fast) on postexercise glycogen resynthesis in soleus muscle and liver from female lean (ZL) and obese insulin-resistant (ZO) Zucker rats. Resting soleus muscle glycogen concentration ([glycogen]) was similar between genotypes and was reduced by 73 (ZL) and 63% (ZO) after exercise (P < 0.05). Liver [glycogen] at rest was greater in ZO than ZL (334 ± 31 vs. 247 ± 16 μmol/g wet wt; P < 0.01) and fell by 44 and 94% after exercise (P < 0.05). The fractional activity of glycogen synthase (active/total) increased immediately after exercise (from 0.22 ± 0.05 and 0.32 ± 0.04 to 0.63 ± 0.08 vs. 0.57 ± 0.05; P < 0.01 for ZL and ZO rats, respectively) and remained elevated above resting values after 30 min of recovery. During this time, muscle [glycogen] in ZO increased 68% with CHO (P < 0.05) but did not change in Fast. Muscle [glycogen] was unchanged in ZL from postexercise values after both treatments. After 6 h recovery, GLUT-4 protein concentration was increased above resting levels by a similar extent for both genotypes in both fasted (∼45%) and CHO-supplemented (∼115%) rats. Accordingly, during this time CHO refeeding resulted in supercompensation in both genotypes (68% vs. 44% for ZL and ZO). With CHO, liver [glycogen] was restored to resting levels in ZL but remained at postexercise values for ZO after both treatments. We conclude that the increased glucose availability with carbohydrate refeeding after glycogen-depleting exercise resulted in glycogen supercompensation, even in the face of muscle insulin-resistance.

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Many women with schizophrenia remain symptomatic despite optimal use of current therapies. While previous studies suggest that adjunctive oestrogen therapy might be effective, large-scale clinical trials are required before clinical applications are possible. This study is the first large-scale randomized-controlled trial in women with treatment-resistant schizophrenia. This Definitive Oestrogen Patch Trial was an 8-week, three-arm, double-blind, randomized-controlled trial conducted between 2006 and 2011. The 183 female participants were aged between 18 and 45 (mean=35 years), with schizophrenia or schizoaffective disorder and ongoing symptoms of psychosis (Positive and Negative Syndrome Scale, PANSS score>60) despite a stable dose of antipsychotic medication for at least 4 weeks. Mean duration of illness was more than 10 years. Participants received transdermal estradiol 200 μg, transdermal estradiol 100 μg or an identical placebo patch. For the 180 women who completed the study, the a priori outcome measure was the change in PANSS score measured at baseline and days 7, 14, 28 and 56. Cognition was assessed at baseline and day 56 using the Repeatable Battery of Neuropsychological Status. Data were analysed using latent growth curve modelling. Both estradiol groups had greater decreases in PANSS positive, general and total symptoms compared with the placebo group (P<0.01), with a greater effect seen for 200 μg than 100 μg estradiol. The largest effect size was for the positive subscale of PANSS in the estradiol 200 μg treatment group (effect size 0.44, P<0.01). This study shows estradiol is an effective and clinically significant adjunctive therapy for women with treatment-resistant schizophrenia, particularly for positive symptoms.Molecular Psychiatry advance online publication, 15 April 2014; doi:10.1038/mp.2014.33.

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Major depressive disorder is a prevalent and disabling illness. Notwithstanding numerous advances in the pharmacological treatment of depression, approximately 70% of patients do not remit after first-line antidepressant treatment.

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 Falling at speed onto a tarmac surface during cycling can cause abrasion and laceration of the skin and body tissue. Motorcycle clothing designed to reduce or avoid this type of injury has traditionally been made of animal leather as it has well known resistance to abrasion. In the last 20 years there has been an emergence of textile clothing reinforced with high performance/tenacity fibres such as those made from polyamides, aramids, ultra high molecular weight polyethylene and liquid crystal. Almost no comparative work has been undertaken to provide insight into the level of protection these clothing layers can provide.
This work has used a CE standard test method to evaluate a number of abrasion resistant textile pant products and compare them with a leather race product. It analysed the protective fabric layer structure for mass, thickness, construction method and resistance to abrasion.
Structures manufactured from high tenacity fibres performed better than those from lower tenacity ones. Fabric construction method and mass per unit area were the two key variables in providing an abrasion protective layer. Structures manufactured from knitted para-aramid fibres performed better than their woven counterparts due to the method of fabric failure. Several well designed protective layers performed at a similar level to that of leather; however, most garments tested failed to meet the lower level European standard of abrasion resistance (CE level 1), which may put their wearer at risk in the advent of a collision.

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Biofilm formation on membranes during water desalination operation and pre-treatments limits performance and causes premature membrane degradation. Here, we apply a novel surface modification technique to incorporate anti-microbial metal particles into the outer layer of four types of commercial polymeric membranes by cold spray. The particles are anchored on the membrane surface by partial embedment within the polymer matrix. Although clear differences in particle surface loadings and response to the cold spray were shown by SEM, the hybrid micro-filtration and ultra-filtration membranes were found to exhibit excellent anti-bacterial properties. Poly(sulfone) ultra-filtration membranes were used as for cross-flow filtration of Escherichia coli bacteria solutions to investigate the impact of the cold spray on the material[U+05F3]s integrity. The membranes were characterized by SEM-EDS, FT-IR and TGA and challenged in filtration tests. No bacteria passed through the membrane and filtrate water quality was good, indicating the membranes remained intact. No intact bacteria were found on hybrid membranes, loaded with up to 15. wt% silver, indicating the treatment was lysing bacteria on contact. However, permeation of the hybrid membranes was found to be reduced compared to control non-modified poly(sulfone) membranes due to the presence of the particles across the membrane material. The implementation of cold spray technology for the modification of commercial membrane products could lead to significant operational savings in the field of desalination and water pre-treatments.

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Diverse strain types of methicillin-resistant Staphylococcus aureus (MRSA) cause infections in community settings worldwide. To examine heterogeneity of spread within households and to identify common risk factors for household transmission across settings, primary data from studies conducted in New York (USA), Breda (The Netherlands), and Melbourne (Australia) were pooled. Following MRSA infection of the index patient, household members completed questionnaires and provided nasal swabs. Swabs positive for S. aureus were genotyped by spa sequencing. Poisson regression with robust error variance was used to estimate prevalence odds ratios for transmission of the clinical isolate to non-index household members. Great diversity of strain types existed across studies. Despite differences between studies, the index patient being colonized with the clinical isolate at the home visit (P < 0·01) and the percent of household members aged <18 years (P < 0·01) were independently associated with transmission. Targeted decolonization strategies could be used across geographical settings to limit household MRSA transmission.

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Drug resistance is frequently found in cancer patients who have prolonged chemotherapeutic treatments. Overcoming this phenomenon to make therapy available to these patients is one of the most important features in developing effective cancer therapeutic strategies. Identification of drug resistance causative molecules is one of the most focused areas of cancer research today. Many molecules have been identified in conferring cancer cells the property of drug resistance, and various small molecule inhibitors have been developed to target these molecules to restore the sensitivity of different traditional chemotherapeutic agents, which are frequently found to exhibit reduced potency during prolonged treatment, in cancer patients. Survivin, a member of the inhibitor of apoptosis proteins (IAP) family, has been identified as one of the most crucial biomarkers in the recognition of drug resistance. Survivin is overexpressed in tumor cells, helping in its proliferation and survival, and its overexpression is positively correlated with poor prognosis for cancer patients. Targeted therapeutic measures to inhibit survivin in cancers, particularly drug-resistant tumors, are the recent focus of research for cancer treatment.

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Introduction N-Acetylcysteine (NAC) may have efficacy in treating tobacco use disorder (TUD) by reducing craving and smoking reward. This study examines whether treatment with NAC may have a clinical efficacy in the treatment of TUD. Methods A 12-week double blind randomized controlled trial was conducted to compare the clinical efficacy of NAC 3 g/day versus placebo. We recruited 34 outpatients with therapy resistant TUD concurrently treated with smoking-focused group behavioral therapy. Participants had assessments of daily cigarette use (primary outcome), exhaled carbon monoxide (COEXH) (secondary outcome), and quit rates as defined by COEXH<6 ppm. Depression was measured with the Hamilton Depression Rating Scale (HDRS). Data were analyzed using conventional and modified intention-to-treat endpoint analyses. Results NAC treatment significantly reduced the daily number of cigarettes used (Δ mean±SD = -10.9 ± 7.9 in the NAC-treated versus -3.2 ± 6.1 in the placebo group) and COEXH (Δ mean± SD = -10.4 ± 8.6 ppm in the NAC-treated versus -1.5 ± 4.5 ppm in the placebo group); 47.1% of those treated with NAC versus 21.4% of placebo-treated patients were able to quit smoking as defined by COEXH<6 ppm. NAC treatment significantly reduced the HDRS score in patients with tobacco use disorder. Conclusions These data show that treatment with NAC may have a clinical efficacy in TUD. NAC combined with appropriate psychotherapy appears to be an efficient treatment option for TUD.

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Evidence of the antidepressant efficacy of lamotrigine is increasing, although there are no placebo-controlled trials of lamotrigine augmentation in depression. The aim of this study was to assess if augmentation with lamotrigine was superior to placebo in patients who were receiving fluoxetine for resistant major depressive episodes.

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Background Cabazitaxel, abiraterone, and enzalutamide are survival-prolonging treatments in men with castration-resistant prostate cancer (CRPC) progressing following docetaxel chemotherapy. The sequential activity of these agents has not been studied and treatment sequencing remains a key dilemma for clinicians. Objective To describe the antitumour activity of cabazitaxel after docetaxel and next-generation endocrine agents. Design, setting, and participants We report on a cohort of 59 men with progressing CRPC treated with cabazitaxel, 37 of whom had received prior abiraterone and 9 of whom had received prior enzalutamide. Outcome measurements and statistical analysis Changes in prostate-specific antigen (PSA) level were used to determine activity on abiraterone, enzalutamide, and cabazitaxel treatment. Radiologic tumour regressions according to Response Evaluation Criteria in Solid Tumors (RECIST) and symptomatic benefit were evaluated for cabazitaxel therapy. Results and limitations The post-endocrine-therapy patients received abiraterone (n = 32), sequential abiraterone and enzalutamide (n = 5) or enzalutamide (n = 4). These patients received a median of 7 mo of abiraterone and 11 mo of enzalutamide. A median of six cabazitaxel cycles (range: 1-10 cycles) were delivered, with ≥50% PSA declines in 16 of 41 (39%) patients, soft tissue radiologic responses in 3 of 22 (14%) evaluable patients, and symptomatic benefit in 9 of 37 evaluable patients (24%). Median overall survival and progression-free survival were 15.8 and 4.6 mo, respectively. Antitumor activity on cabazitaxel was less favourable in the abiraterone- and enzalutamide-naïve cohort (n = 18), likely reflecting biologic differences in this cohort. These data were obtained from a retrospective analysis. Conclusions This is the first report of cabazitaxel activity in CRPC progressing after treatment with docetaxel and abiraterone or enzalutamide. We demonstrate significant cabazitaxel activity in this setting. Patient summary We looked at the antitumour activity of the chemotherapy drug cabazitaxel in men previously treated with docetaxel chemotherapy and the hormonal drugs abiraterone and enzalutamide. Cabazitaxel appeared active when given after abiraterone and enzalutamide. We can reassure men that cabazitaxel can be used after these novel endocrine treatments. © 2013 European Association of Urology.

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Many women with schizophrenia remain symptomatic despite optimal use of current therapies. While previous studies suggest that adjunctive oestrogen therapy might be effective, large-scale clinical trials are required before clinical applications are possible. This study is the first large-scale randomized-controlled trial in women with treatment-resistant schizophrenia. This Definitive Oestrogen Patch Trial was an 8-week, three-arm, double-blind, randomized-controlled trial conducted between 2006 and 2011. The 183 female participants were aged between 18 and 45 (mean=35 years), with schizophrenia or schizoaffective disorder and ongoing symptoms of psychosis (Positive and Negative Syndrome Scale, PANSS score>60) despite a stable dose of antipsychotic medication for at least 4 weeks. Mean duration of illness was more than 10 years. Participants received transdermal estradiol 200 μg, transdermal estradiol 100 μg or an identical placebo patch. For the 180 women who completed the study, the a priori outcome measure was the change in PANSS score measured at baseline and days 7, 14, 28 and 56. Cognition was assessed at baseline and day 56 using the Repeatable Battery of Neuropsychological Status. Data were analysed using latent growth curve modelling. Both estradiol groups had greater decreases in PANSS positive, general and total symptoms compared with the placebo group (P<0.01), with a greater effect seen for 200 μg than 100 μg estradiol. The largest effect size was for the positive subscale of PANSS in the estradiol 200 μg treatment group (effect size 0.44, P<0.01). This study shows estradiol is an effective and clinically significant adjunctive therapy for women with treatment-resistant schizophrenia, particularly for positive symptoms.