Rods to discs in the study of mesomorphism in discotic liquid crystals

The rational design of calamitic liquid crystals is an area of research that has been intensively explored due to their extensive applications in various devices. The successful methods for design have been, to some extent, mapped on discotic systems such that certain features of the structures of calamitic phases have been superimposed upon those of nematic discotic and columnar phases. In this article, we explore the correlation between nematogenic behaviour of hard rod-like particles and that of hard disc-like systems. We show that for calamitics, nematic behaviour is observed, whereas for discotics this is not the case. Furthermore, we show that nematic discotic materials are miscible, whereas unlike smectics, columnar phases are less likely to be miscible. Indeed, it appears that columnar discotic phases are greater similarities with soft-solids than true liquid crystals

Suboptimal asthma care for immigrant children: results of an audit study

<p>Abstract</p> <p>Background</p> <p>Little is known on the scope and nature of ethnic inequalities in suboptimal asthma care for children. This study aimed to assess (1) ethnic differences in suboptimal asthma care for children with an asthma exacerbation who consulted a physician, and (2) ethnic differences in the nature of suboptimal care.</p> <p>Methods</p> <p>All children aged 6–16 years who during a period of six months consulted the paediatric department of the Academic Medical Centre-University of Amsterdam or one of the six regional primary care centres with an asthma exacerbation were included. Clinical guidelines were systematically converted to review criteria following the strategy as proposed by the Agency for Health Care Policy and Research. Based upon these review criteria and their experience experts of two multidisciplinary panels retrospectively assessed the quality of care and its (possible) failure to prevent the occurrence of asthma exacerbation.</p> <p>Results</p> <p>Only a small number of children (n = 35) were included in the analysis as a result of which the ethnic differences in suboptimal care were not significant. However, the results do indicate immigrant children, in particular 'other non-Western' children (n = 11), more frequently to receive suboptimal care related to the asthma exacerbation when compared to ethnic Dutch children. Furthermore, we found the nature of suboptimal care to differ with under-prescribing in the 'other non-Western' group (n = 11), lack of information exchange between physicians in the Surinamese/Antillean group (n = 12) and lack of education, and counselling of patients and parents in the ethnic Dutch (n = 12) as the most relevant factor.</p> <p>Conclusion</p> <p>Ethnic inequalities in the scope and nature of suboptimal asthma care for children in the Netherlands seem to exist. For the non-western immigrant groups the results indicate the importance of the prescription behaviour of the medical doctor, as well as the supervision by one health care provider.</p

Ethnic diversity outpatient clinic in paediatrics

<p>Abstract</p> <p>Background</p> <p>The health status of chronic sick ethnic minority children in the Netherlands is unequal compared with indigenous Dutch children. In order to optimize the health care for these children a specific patient-oriented clinic in ethnic-cultural diversity: the Mosaic Outpatient Clinic (MOC) was integrated in the general Paediatric Outpatient Departments (POPD) of three hospitals in Amsterdam.</p> <p>Methods</p> <p>Feasibility of the MOC, factors influencing the health care process and encountered bottlenecks in health care were studied in ethnic minority children with asthma, diabetes type 1 or metabolic disease originating from Morocco, Turkey and Surinam. Feasibility was determined by the number of patients attended, support from the paediatric medical staff and willingness of the patients to participate. Influences on the health care process comprised parents' level of knowledge of disease, sense of disease severity, level of effort, linguistic skills, health literacy, adherence to treatment and encountered bottlenecks in the health care process. Moreover, the number of admissions and visits to the POPD in the years before, during and after the MOC were analysed.</p> <p>Results</p> <p>In 2006 a total of 189 ethnic minority children were seen. Integration of the MOC within the general POPD of the hospital is feasible. The ability of the parents to speak and understand Dutch was found to be 58%, functional health literacy was 88%; sufficient knowledge of disease and sense of disease severity were 59% and 67%, respectively.</p> <p>The main bottlenecks in the healthcare process: poor knowledge of disease, limited sense of disease severity and low health literacy in the parents proved to be the best predictors for decreased adherence. After attending the MOC there was a decrease in the number of admissions and visits to the POPD for asthma while the number of visits increased in patients with diabetes and the amount of no-shows decreased in patients with a metabolic disease.</p> <p>Conclusion</p> <p>Integration of a MOC in the general POPD is feasible and appreciated by the parents, provides more insight in the problems ethnic minority children and their parents face and shows promising directions for optimizing adherence in these children.</p

Illness perceptions and explanatory models of viral hepatitis B & C among immigrants and refugees: a narrative systematic review.

© 2015 Owiti et al.; licensee BioMed Central. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.BACKGROUND: Hepatitis B and C (HBV, HCV) infections are associated with high morbidity and mortality. Many countries with traditionally low prevalence (such as UK) are now planning interventions (screening, vaccination, and treatment) of high-risk immigrants from countries with high prevalence. This review aimed to synthesise the evidence on immigrants' knowledge of HBV and HCV that might influence the uptake of clinical interventions. The review was also used to inform the design and successful delivery of a randomised controlled trial of targeted screening and treatment. METHODS: Five databases (PubMed, CINHAL, SOCIOFILE, PsycINFO & Web of Science) were systematically searched, supplemented by reference tracking, searches of selected journals, and of relevant websites. We aimed to identify qualitative and quantitative studies that investigated knowledge of HBV and HCV among immigrants from high endemic areas to low endemic areas. Evidence, extracted according to a conceptual framework of Kleinman's explanatory model, was subjected to narrative synthesis. We adapted the PEN-3 model to categorise and analyse themes, and recommend strategies for interventions to influence help-seeking behaviour. RESULTS: We identified 51 publications including quantitative (n = 39), qualitative (n = 11), and mixed methods (n = 1) designs. Most of the quantitative studies included small samples and had heterogeneous methods and outcomes. The studies mainly concentrated on hepatitis B and ethnic groups of South East Asian immigrants residing in USA, Canada, and Australia. Many immigrants lacked adequate knowledge of aetiology, symptoms, transmission risk factors, prevention strategies, and treatment, of hepatitis HBV and HCV. Ethnicity, gender, better education, higher income, and English proficiency influenced variations in levels and forms of knowledge. CONCLUSION: Immigrants are vulnerable to HBV and HCV, and risk life-threatening complications from these infections because of poor knowledge and help-seeking behaviour. Primary studies in this area are extremely diverse and of variable quality precluding meta-analysis. Further research is needed outside North America and Australia

Human SOD2 Modification by Dopamine Quinones Affects Enzymatic Activity by Promoting Its Aggregation: Possible Implications for Parkinson’s Disease

Mitochondrial dysfunction and oxidative stress are considered central in dopaminergic neurodegeneration in Parkinson’s disease (PD). Oxidative stress occurs when the endogenous antioxidant systems are overcome by the generation of reactive oxygen species (ROS). A plausible source of oxidative stress, which could account for the selective degeneration of dopaminergic neurons, is the redox chemistry of dopamine (DA) and leads to the formation of ROS and reactive dopamine-quinones (DAQs). Superoxide dismutase 2 (SOD2) is a mitochondrial enzyme that converts superoxide radicals to molecular oxygen and hydrogen peroxide, providing a first line of defense against ROS. We investigated the possible interplay between DA and SOD2 in the pathogenesis of PD using enzymatic essays, site-specific mutagenesis, and optical and high-field-cw-EPR spectroscopies. Using radioactive DA, we demonstrated that SOD2 is a target of DAQs. Exposure to micromolar DAQ concentrations induces a loss of up to 50% of SOD2 enzymatic activity in a dose-dependent manner, which is correlated to the concomitant formation of protein aggregates, while the coordination geometry of the active site appears unaffected by DAQ modifications. Our findings support a model in which DAQ-mediated SOD2 inactivation increases mitochondrial ROS production, suggesting a link between oxidative stress and mitochondrial dysfunction

Gaining Greater Insight into HCV Emergence in HIV-Infected Men Who Have Sex with Men: The HEPAIG Study

OBJECTIVES: The HEPAIG study was conducted to better understand Hepatitis C virus (HCV) transmission among human immuno-deficiency (HIV)-infected men who have sex with men (MSM) and assess incidence of HCV infection among this population in France. METHODS AND RESULTS: Acute HCV infection defined by anti-HCV or HCV ribonucleic acid (RNA) positivity within one year of documented anti-HCV negativity was notified among HIV-infected MSM followed up in HIV/AIDS clinics from a nationwide sampling frame. HIV and HCV infection characteristics, HCV potential exposures and sexual behaviour were collected by the physicians and via self-administered questionnaires. Phylogenetic analysis of the HCV-NS5B region was conducted. HCV incidence was 48/10 000 [95% Confidence Interval (CI):43-54] and 36/10 000 [95% CI: 30-42] in 2006 and 2007, respectively. Among the 80 men enrolled (median age: 40 years), 55% were HIV-diagnosed before 2000, 56% had at least one sexually transmitted infection in the year before HCV diagnosis; 55% were HCV-infected with genotype 4 (15 men in one 4d-cluster), 32.5% with genotype 1 (three 1a-clusters); five men were HCV re-infected; in the six-month preceding HCV diagnosis, 92% reported having casual sexual partners sought online (75.5%) and at sex venues (79%), unprotected anal sex (90%) and fisting (65%); using recreational drugs (62%) and bleeding during sex (55%). CONCLUSIONS: This study emphasizes the role of multiple unprotected sexual practices and recreational drugs use during sex in the HCV emergence in HIV-infected MSM. It becomes essential to adapt prevention strategies and inform HIV-infected MSM with recent acute HCV infection on risk of re-infection and on risk-reduction strategies

Amebiasis in HIV-1-Infected Japanese Men: Clinical Features and Response to Therapy

Invasive amebic diseases caused by Entamoeba histolytica are increasing among men who have sex with men and co-infection of ameba and HIV-1 is an emerging problem in developed East Asian countries. To characterize the clinical and epidemiological features of invasive amebiasis in HIV-1 patients, the medical records of 170 co-infected cases were analyzed retrospectively, and E. histolytica genotype was assayed in 14 cases. In this series of HIV-1-infected patients, clinical presentation of invasive amebiasis was similar to that described in the normal host. High fever, leukocytosis and high CRP were associated with extraluminal amebic diseases. Two cases died from amebic colitis (resulting in intestinal perforation in one and gastrointestinal bleeding in one), and three cases died from causes unrelated to amebiasis. Treatment with metronidazole or tinidazole was successful in the other 165 cases. Luminal treatment was provided to 83 patients following metronidazole or tinidazole treatment. However, amebiasis recurred in 6 of these, a frequency similar to that seen in patients who did not receive luminal treatment. Recurrence was more frequent in HCV-antibody positive individuals and those who acquired syphilis during the follow-up period. Various genotypes of E. histolytica were identified in 14 patients but there was no correlation between genotype and clinical features. The outcome of metronidazole and tinidazole treatment of uncomplicated amebiasis was excellent even in HIV-1-infected individuals. Luminal treatment following metronidazole or tinidazole treatment does not reduce recurrence of amebiasis in high risk populations probably due to amebic re-infection