Impedance-based sensor for potassium ions.

A conductometric sensor for potassium ions in solution is presented. Interdigitated, planar gold electrodes were coated with a potassium-selective polymer membrane composed of a poly(vinyl chloride) matrix with about 65 wt% of plasticiser and 2-5 wt% of a potassium-selective ionophore. The impedance of the membrane was measured, using the electrodes as a transducer, and related to the concentration of potassium in a sample solution in contact with the membrane. Sensitivity was optimised by varying the sensor components, and selectivity for potassium over sodium was also shown. The resulting devices are compact, miniature, robust sensors which, by means of impedance measurements, eliminate the need for a reference electrode. The sensor was tested for potassium concentration changes of 2 mM across the clinically relevant range of 2.7-18.7 mM.Henslow Fellowship, Darwin College, Cambridge L'Oreal -UNESCO UK & Ireland Fellowship For Women In Scienc

Modifying the Sum Over Topological Sectors and Constraints on Supergravity

The standard lore about the sum over topological sectors in quantum field theory is that locality and cluster decomposition uniquely determine the sum over such sectors, thus leading to the usual theta-vacua. We show that without changing the local degrees of freedom, a theory can be modified such that the sum over instantons should be restricted; e.g. one should include only instanton numbers which are divisible by some integer p. This conclusion about the configuration space of quantum field theory allows us to carefully reconsider the quantization of parameters in supergravity. In particular, we show that FI-terms and nontrivial Kahler forms are quantized. This analysis also leads to a new derivation of recent results about linearized supergravity.Comment: 17 pages, minor change

Fasting and postchallenge glycemia and cardiovascular disease risk. The Framingham Offspring Study

WSTĘP. Celem pracy było zbadanie słuszności hipotezy, według której hiperglikemia na czczo (FHG, fasting hyperglycemia) i glikemia 2 godziny po obciążeniu glukozą (2hPG, 2-h postchallenge glycemia) niezależnie zwiększają ryzyko chorób sercowo-naczyniowych (CVD, cardiovascular disease). MATERIAŁ I METODY. W latach 1991-1995 autorzy przebadali 3370 uczestników badania Framingham Offspring Study, u których nie występowały objawy kliniczne CVD (choroba wieńcowa, udar mózgu lub chromanie przestankowe) ani cukrzyca, wymagająca leczenia farmakologicznego. Okres obserwacji pod kątem występowania CVD wynosił 4 lata. W celu oceny ryzyka związanego z FHG (stężenie glukozy na czczo ł 7,0 mmol/l) i 2hPG niezależnie od wpływu standardowych czynników ryzyka CVD, zastosowano model regresji proporcjonalnego ryzyka Coxa. WYNIKI. Średni wiek badanych wynosił 54 lata, 54% chorych stanowiły kobiety. Uprzednio nierozpoznaną cukrzycę stwierdzono u 3,2% na podstawie FHG, a u 4,9% (164 osoby), opierając się na wartościach FHG lub 2hPG ł 11,1 mmol/l. Spośród tych 164 chorych u 55 (33,5%) 2hPG było ł 11,1 mmol/ przy prawidłowym FHG, ale stanowiły one jedynie 1,7% z 3261 badanych bez FHG. W czasie 12 242 pacjentolat obserwacji wystąpiło 118 incydentów CVD. W oddzielnych modelach, skorygowanych względem płci i standardowych czynników ryzyka chorób sercowo-naczyniowych, ryzyko względne (RR, relative risk) CVD dla glikemii na czczo (FPG, fasting plasma glucose) większej lub równej 7,0 mmol/l wynosiło 2,8 (95% przedział ufności 1,6–5,0), a dla wzrostu 2hPG o 2,1 mmol/l - 1,2 (1,1–1,3). W modelu wspólnym RR dla FHG zmalało i wynosiło 1,5 (0,7–3,6), podczas gdy RR dla 2hPG pozostało istotnie podwyższone (1,1; 1,02–1,3). Analiza statystyczna c dla modelu obejmującego jedynie standardowe czynniki ryzyka CVD wyniosła 0,744; po dołączeniu FHG - 0,746, a po dodaniu FHG i 2hPG - 0,752. WNIOSKI. Glikemia po doustnym obciążeniu glukozą jest niezależnym czynnikiem ryzyka chorób sercowo-naczyniowych, ale wartość predykcyjna 2hPG jest niewielka w stosunku do standardowych czynników ryzyka CVD.INTRODUCTION. To test the hypothesis that fasting hyperglycemia (FHG) and 2-h postchallenge glycemia (2hPG) independently increase the risk for cardiovascular disease (CVD). MATERIAL AND METHODS. During 1991–1995, we examined 3,370 subjects from the Framingham Offspring Study who were free from clinical CVD (coronary heart disease, stroke, or intermittent claudication) or medication-treated diabetes, and we followed them for 4 years for incident CVD events. We used proportional-hazards regression to assess the risk associated with FHG (fasting plasma glucose ≥ 7.0 mmol/l) and 2hPG, independent of the risk predicted by standard CVD risk factors. RESULTS. Mean subject age was 54 years, 54% were women, and previously undiagnosed diabetes was present in 3.2% by FHG and 4.9% (164) by FHG or a 2hPG ≥ 11.1 mmol/l. Of these 164 subjects, 55 (33.5%) had 2hPG ≥ 11.1 without FHG, but these 55 subjects represented only 1.7% of the 3,261 subjects without FHG. During 12,242 person-years of follow-up, there were 118 CVD events. In separate sex- and CVD risk-adjusted models, relative risk (RR) for CVD with fasting plasma glucose ≥ 7.0 mmol/l was 2.8 (95% CI 1.6–5.0); RR for CVD per 2.1 mmol/l increase in 2hPG was 1.2 (1.1–1.3). When modeled together, the RR for FHG decreased to 1.5 (0.7–3.6), whereas the RR for 2hPG remained significant (1.1, 1.02–1.3). The c-statistic for a model including CVD risk factors alone was 0.744; with addition of FHG, it was 0.746, and with FHG and 2hPG, it was 0.752. CONCLUSIONS. Postchallenge hyperglycemia is an independent risk factor for CVD, but the marginal predictive value of 2hPG beyond knowledge of standard CVD risk factors is small

Primary sclerosing lipogranuloma: an unusual scrotal mass

Sclerosing lipogranuloma (SLG) of the male external genitalia is a rare benign condition presenting as subcutaneous masses. The underlying pathological process is a granulomatous reaction of fatty tissue in this area. The cause of this is unclear but hypothesis stems around the pathogenesis of exogenous lipid degeneration from injection of foreign bodies such as paraffin for penile augmentation. However, endogenous lipid degeneration from other various causes such as infection, trauma, and allergic mechanisms has also been reported. We present the case of a 40-year-old man with primary SLG of the external genitalia. Literature review on the treatment strategies are addressed and discussed

Surgical Management of Inguinal Hernias at Bugando Medical Centre in Northwestern Tanzania: Our Experiences in a Resource-Limited Setting.

Inguinal hernia repair remains the commonest operation performed by general surgeons all over the world. There is paucity of published data on surgical management of inguinal hernias in our environment. This study is intended to describe our own experiences in the surgical management of inguinal hernias and compare our results with that reported in literature. A descriptive prospective study was conducted at Bugando Medical Centre in northwestern Tanzania. Ethical approval to conduct the study was obtained from relevant authorities before the commencement of the study. Statistical data analysis was done using SPSS software version 17.0. A total of 452 patients with inguinal hernias were enrolled in the study. The median age of patients was 36 years (range 3 months to 78 years). Males outnumbered females by a ratio of 36.7:1. This gender deference was statistically significant (P=0.003). Most patients (44.7%) presented late (more than five years of onset of hernia). Inguinoscrotal hernia (66.8%) was the commonest presentation. At presentation, 208 (46.0%) patients had reducible hernia, 110 (24.3%) had irreducible hernia, 84 (18.6%) and 50(11.1%) patients had obstructed and strangulated hernias respectively. The majority of patients (53.1%) had right sided inguinal hernia with a right-to-left ratio of 2.1: 1. Ninety-two (20.4%) patients had bilateral inguinal hernias. 296 (65.5%) patients had indirect hernia, 102 (22.6%) had direct hernia and 54 (11.9%) had both indirect and direct types (pantaloon hernia). All patients in this study underwent open herniorrhaphy. The majority of patients (61.5%) underwent elective herniorrhaphy under spinal anaesthesia (69.2%). Local anaesthesia was used in only 1.1% of cases. Bowel resection was required in 15.9% of patients. Modified Bassini's repair (79.9%) was the most common technique of posterior wall repair of the inguinal canal. Lichtenstein mesh repair was used in only one (0.2%) patient. Complication rate was 12.4% and it was significantly higher in emergency herniorrhaphy than in elective herniorrhaphy (P=0.002). The median length of hospital stay was 8 days and it was significantly longer in patients with advanced age, delayed admission, concomitant medical illness, high ASA class, the need for bowel resection and in those with surgical repair performed under general anesthesia (P<0.001). Mortality rate was 9.7%. Longer duration of symptoms, late hospitalization, coexisting disease, high ASA class, delayed operation, the need for bowel resection and presence of complications were found to be predictors of mortality (P<0.001). Inguinal hernias continue to be a source of morbidity and mortality in our centre. Early presentation and elective repair of inguinal hernias is pivotal in order to eliminate the morbidity and mortality associated with this very common problem

Characteristics of outdoor falls among older people: A qualitative study

Background Falls are a major threat to older people’s health and wellbeing. Approximately half of falls occur in outdoor environments but little is known about the circumstances in which they occur. We conducted a qualitative study to explore older people’s experiences of outdoor falls to develop understanding of how they may be prevented. Methods We conducted nine focus groups across the UK (England, Wales, and Scotland). Our sample was from urban and rural settings and different environmental landscapes. Participants were aged 65+ and had at least one outdoor fall in the past year. We analysed the data using framework and content analyses. Results Forty-four adults aged 65 – 92 took part and reported their experience of 88 outdoor falls. Outdoor falls occurred in a variety of contexts, though reports suggested the following scenarios may have been more frequent: when crossing a road, in a familiar area, when bystanders were around, and with an unreported or unknown attribution. Most frequently, falls resulted in either minor or moderate injury, feeling embarrassed at the time of the fall, and anxiety about falling again. Ten falls resulted in fracture, but no strong pattern emerged in regard to the contexts of these falls. Anxiety about falling again appeared more prevalent among those that fell in urban settings and who made more visits into their neighbourhood in a typical week. Conclusions This exploratory study has highlighted several aspects of the outdoor environment that may represent risk factors for outdoor falls and associated fear of falling. Health professionals are recommended to consider outdoor environments as well as the home setting when working to prevent falls and increase mobility among older people

Trauma history and depression predict incomplete adherence to antiretroviral therapies in a low income country.

As antiretroviral therapy (ART) for HIV becomes increasingly available in low and middle income countries (LMICs), understanding reasons for lack of adherence is critical to stemming the tide of infections and improving health. Understanding the effect of psychosocial experiences and mental health symptomatology on ART adherence can help maximize the benefit of expanded ART programs by indicating types of services, which could be offered in combination with HIV care. The Coping with HIV/AIDS in Tanzania (CHAT) study is a longitudinal cohort study in the Kilimanjaro Region that included randomly selected HIV-infected (HIV+) participants from two local hospital-based HIV clinics and four free-standing voluntary HIV counselling and testing sites. Baseline data were collected in 2008 and 2009; this paper used data from 36 month follow-up interviews (N = 468). Regression analyses were used to predict factors associated with incomplete self-reported adherence to ART. INCOMPLETE ART ADHERENCE WAS SIGNIFICANTLY MORE LIKELY TO BE REPORTED AMONGST PARTICIPANTS WHO EXPERIENCED A GREATER NUMBER OF CHILDHOOD TRAUMATIC EVENTS: sexual abuse prior to puberty and the death in childhood of an immediate family member not from suicide or homicide were significantly more likely in the non-adherent group and other negative childhood events trended toward being more likely. Those with incomplete adherence had higher depressive symptom severity and post-traumatic stress disorder (PTSD). In multivariable analyses, childhood trauma, depression, and financial sacrifice remained associated with incomplete adherence.\ud This is the first study to examine the effect of childhood trauma, depression and PTSD on HIV medication adherence in a low income country facing a significant burden of HIV. Allocating spending on HIV/AIDS toward integrating mental health services with HIV care is essential to the creation of systems that enhance medication adherence and maximize the potential of expanded antiretroviral access to improve health and reduce new infections

PRISM protocol: A randomised phase II trial of nivolumab in combination with alternatively scheduled ipilimumab in first-line treatment of patients with advanced or metastatic renal cell carcinoma

Background The combination of nivolumab, a programmed death-1 (PD-1) targeted monoclonal antibody, with the cytotoxic T-lymphocyte antigen-4 (CTLA-4) targeted antibody, ipilimumab, represents a new standard of care in the first-line setting for patients with intermediate- and poor-risk metastatic renal cell carcinoma (mRCC) based on recent phase III data. Combining ipilimumab with nivolumab increases rates of grade 3 and 4 toxicity compared with nivolumab alone, and the optimal scheduling of these agents when used together remains unknown. The aim of the PRISM study is to assess whether less frequent dosing of ipilimumab (12-weekly versus 3-weekly), in combination with nivolumab, is associated with a favourable toxicity profile without adversely impacting efficacy. Methods The PRISM trial is a UK-based, open label, multi-centre, phase II, randomised controlled trial. The trial population consists of patients with untreated locally advanced or metastatic clear cell RCC, and aims to recruit 189 participants. Participants will be randomised on a 2:1 basis in favour of a modified schedule of 4 doses of 12-weekly ipilimumab versus a standard schedule of 4 doses of 3-weekly ipilimumab, both in combination with standard nivolumab. The proportion of participants experiencing a grade 3 or 4 adverse reaction within 12 months forms the primary endpoint of the study, but with 12-month progression free survival a key secondary endpoint. The incidence of all adverse events, discontinuation rates, overall response rate, duration of response, overall survival rates and health related quality of life will also be analysed as secondary endpoints. In addition, the potential of circulating and tissue-based biomarkers as predictors of therapy response will be explored. Discussion The combination of nivolumab with ipilimumab is active in patients with mRCC. Modifying the frequency of ipilimumab dosing may mitigate toxicity rates and positively impact quality of life without compromising efficacy, a hypothesis being explored in other tumour types such as non-small cell lung cancer. The best way to give this combination to patients with mRCC must be similarly established

Combinatorial CRISPR-Cas9 screens for de novo mapping of genetic interactions.

We developed a systematic approach to map human genetic networks by combinatorial CRISPR-Cas9 perturbations coupled to robust analysis of growth kinetics. We targeted all pairs of 73 cancer genes with dual guide RNAs in three cell lines, comprising 141,912 tests of interaction. Numerous therapeutically relevant interactions were identified, and these patterns replicated with combinatorial drugs at 75% precision. From these results, we anticipate that cellular context will be critical to synthetic-lethal therapies