Experimental demonstration of optical stochastic cooling

Particle accelerators and storage rings have been transformative instruments of discovery, and, for many applications, innovations in particle-beam cooling have been a principal driver of that success¹. Stochastic cooling (SC), one of the most important conceptual and technological advances in this area^2–6, cools a beam through granular sampling and correction of its phase-space structure, thus bearing resemblance to a ‘Maxwell’s demon’. The extension of SC from the microwave regime up to optical frequencies and bandwidths has long been pursued, as it could increase the achievable cooling rates by three to four orders of magnitude and provide a powerful tool for future accelerators. First proposed nearly 30 years ago, optical stochastic cooling (OSC) replaces the conventional microwave elements of SC with optical-frequency analogues and is, in principle, compatible with any species of charged-particle beam^7,8. Here we describe a demonstration of OSC in a proof-of-principle experiment at the Fermi National Accelerator Laboratory’s Integrable Optics Test Accelerator^9,10. The experiment used 100-MeV electrons and a non-amplified configuration of OSC with a radiation wavelength of 950 nm, and achieved strong, simultaneous cooling of the beam in all degrees of freedom. This realization of SC at optical frequencies serves as a foundation for more advanced experiments with high-gain optical amplification, and advances opportunities for future operational OSC systems with potential benefit to a broad user community in the accelerator-based sciences.

Stochastic cooling at optical frequencies is demonstrated in an experiment at the Fermi National Accelerator Laboratory’s Integrable Optics Test Accelerator, substantially increasing the bandwidth of stochastic cooling compared with conventional systems.

Population uptake of HIV testing, treatment, viral suppression, and male circumcision following a community-based intervention in Botswana (Ya Tsie/BCPP): a cluster-randomised trial

BACKGROUND

In settings with high HIV prevalence and treatment coverage, such as Botswana, it is unknown whether uptake of HIV prevention and treatment interventions can be increased further. We sought to determine whether a community-based intervention to identify and rapidly treat people living with HIV, and support male circumcision could increase population levels of HIV diagnosis, treatment, viral suppression, and male circumcision in Botswana.

METHODS

The Ya Tsie Botswana Combination Prevention Project study was a pair-matched cluster-randomised trial done in 30 communities across Botswana done from Oct 30, 2013, to June 30, 2018. 15 communities were randomly assigned to receive HIV prevention and treatment interventions, including enhanced HIV testing, earlier antiretroviral therapy (ART), and strengthened male circumcision services, and 15 received standard of care. The first primary endpoint of HIV incidence has already been reported. In this Article, we report findings for the second primary endpoint of population uptake of HIV prevention services, as measured by proportion of people known to be HIV-positive or tested HIV-negative in the preceding 12 months; proportion of people living with HIV diagnosed and on ART; proportion of people living with HIV on ART with viral suppression; and proportion of HIV-negative men circumcised. A longitudinal cohort of residents aged 16-64 years from a random, approximately 20% sample of households across the 15 communities was enrolled to assess baseline uptake of study outcomes; we also administered an end-of-study survey to all residents not previously enrolled in the longitudinal cohort to provide study end coverage estimates. Differences in intervention uptake over time by randomisation group were tested via paired Student's t test. The study has been completed and is registered with ClinicalTrials.gov (NCT01965470).

FINDINGS

In the six communities participating in the end-of-study survey, 2625 residents (n=1304 from standard-of-care communities, n=1321 from intervention communities) were enrolled into the 20% longitudinal cohort at baseline from Oct 30, 2013, to Nov 24, 2015. In the same communities, 10 791 (86%) of 12 489 eligible enumerated residents not previously enrolled in the longitudinal cohort participated in the end-of-study survey from March 30, 2017, to Feb 25, 2018 (5896 in intervention and 4895 in standard-of-care communities). At study end, in intervention communities, 1228 people living with HIV (91% of 1353) were on ART; 1166 people living with HIV (88% of 1321 with available viral load) were virally suppressed, and 673 HIV-negative men (40% of 1673) were circumcised in intervention communities. After accounting for baseline differences, at study end the proportion of people living with HIV who were diagnosed was significantly higher in intervention communities (absolute increase of 9% to 93%) compared with standard-of-care communities (absolute increase of 2% to 88%; prevalence ratio [PR] 1·08 [95% CI 1·02-1·14], p=0·032). Population levels of ART, viral suppression, and male circumcision increased from baseline in both groups, with greater increases in intervention communities (ART PR 1·12 [95% CI 1·07-1·17], p=0·018; viral suppression 1·13 [1·09-1·17], p=0·017; male circumcision 1·26 [1·17-1·35], p=0·029).

INTERPRETATION

It is possible to achieve very high population levels of HIV testing and treatment in a high-prevalence setting. Maintaining these coverage levels over the next decade could substantially reduce HIV transmission and potentially eliminate the epidemic in these areas.

FUNDING

US President's Emergency Plan for AIDS Relief through the Centers for Disease Control and Prevention.

The Microalbuminuria Education Medication and Optimisation (MEMO) study: 4 years follow-up of multifactorial intervention in high-risk individuals with type 2 diabetes

AIMS

The Microalbuminuria Education Medication and Optimisation (MEMO) study, revealed improved cardiovascular risk and glycaemic control with 18 months of intensive multifactorial intervention in high-risk people with type 2 diabetes, without any increase in severe hypoglycaemia. Our aim was to assess longer-term outcomes at 4-year follow-up in these participants.

METHODS

Some 189 individuals with type 2 diabetes and microalbuminuria were recruited from a multi-ethnic population in Leicestershire, UK. The intervention group (n = 95) received multifactorial intervention with self-management education, and the control group (n = 94) received usual care. The primary outcome was change in HbA_1c , and secondary outcomes were blood pressure (BP), cholesterol, microalbuminuria, estimated GFR, cardiovascular risk scores and major adverse cardiovascular events.

RESULTS

Some 130 participants (68.7%), mean (sd) age 60.8 (10.4) years, duration of diabetes 11.5 (9.7) years, completed 4 years of follow-up. Mean change [95% confidence intervals (CI)] in HbA_1c over 4 years was greater with intensive intervention compared with control (-3 mmol/mol, 95% CI -4.95,-1.11; -0.4%, 95% CI -0.67,-0.15; P = 0.002). Significant improvements over the 4 years were also seen in systolic BP (-7.3 mmHg, 95% CI -11.1, -3.5; P < 0.001), diastolic BP (-2.9 mmHg, 95% CI -5.4, -0.3; P = 0.026), cholesterol (-0.3 mmol/l, 95% CI -0.52,-0.12; P = 0.002), and 10-year coronary heart disease (-5.3, 95% CI -8.2,-2.3; P < 0.001) and stroke risk (-4.4, 95% CI -7.5, -1.3; P < 0.001).

CONCLUSION

Multifactorial intervention with structured diabetes self-management education compared with usual diabetes care has benefits for cardio-metabolic risk factor profile. There was no increase in severe hypoglycaemia and cardiovascular mortality despite intensive glycaemic control, although the study was not powered to assess these outcomes.

PO 8719 INTRODUCING A NEW AFRICA MENINGITIS NETWORK – A NORTH-SOUTH COLLABORATION

Background

Central nervous system infections, including meningitis, continue to cause significant morbidity in Africa. HIV has contributed to the epidemiology of CNS infections in this setting. Notable advances in the study of CNS infections by several groups have demonstrated the utility of new diagnostic strategies and impact of novel treatment strategies. However, efforts to coordinate meningitis research in Africa, and between Africa and the rest of the world remain very limited.

Methods

In a bid to promote a coordinated study of CNS infections across Africa, and in collaboration with other meningitis groups globally, the researchers of the AMBITION study (High Dose Ambisome on a Fluconazole Backbone for Cryptococcal Meningitis Induction Therapy in Sub-saharan Africa: A Randomised Controlled Non-inferiority Trial) are leveraging the EDCTP support for the AMBITION trial to set up an Africa Meningitis Trials Network.

Results

The Africa Meningitis Trials Network (AMNET) was launched in Malawi in early 2018. Main achievements since the launch of the network, include an internal review of meningitis research across network sites and launch of the network website. The network also has two study protocols pending ethics review at all sites. These studies will provide much needed information on resources available for meningitis care, research and provide a baseline epidemiology of meningitis in Africa.

Conclusion

AMNET provides a rare opportunity for investigators interested in meningitis research to leverage the ongoing AMBITION trial to conduct Africa-wide preliminary research on meningitis. The network is recruiting additional members in Africa and globally to collaborate on meningitis research, and also apply for research funding to support meningitis work. Anyone interested in knowing more about the network should contact the AMNET communications officer, Ms Phum’lani Machao, phumlani.machao@gmail.com

Genetic Knowledge Among Participants in the Coriell Personalized Medicine Collaborative

Genetic literacy is essential for the effective integration of genomic information into healthcare; yet few recent studies have been conducted to assess the current state of this knowledge base. Participants in the Coriell Personalized Medicine Collaborative (CPMC), a prospective study assessing the impact of personalized genetic risk reports for complex diseases and drug response on behavior and health outcomes, completed genetic knowledge questionnaires and other surveys through an online portal. To assess the association between genetic knowledge and genetic education background, multivariate linear regression was performed. 4 062 participants completed a genetic knowledge and genetic education background questionnaire. Most were older (mean age: 50), Caucasian (90 %), female (59 %), highly educated (69 % bachelor's or higher), with annual household income over $100 000 (49 %). Mean percent correct was 76 %. Controlling for demographics revealed that health care providers, participants previously exposed to genetics, and participants with 'better than most' self-rated knowledge were significantly more likely to have a higher knowledge score (p < 0.001). Overall, genetic knowledge was high with previous genetic education experience predictive of higher genetic knowledge score. Education is likely to improve genetic literacy, an important component to expanded use of genomics in personalized medicine.

New insulins and newer insulin regimens: a review of their role in improving glycaemic control in patients with diabetes

The legacy effect of early good glycaemic control in people with diabetes shows it is associated with reduction of microvascular and macrovascular complications. Insulin therapy is essential and lifesaving in individuals with type 1 diabetes and beneficial for those with type 2 diabetes who fail to achieve optimal glycaemic targets with other classes of glucose-lowering therapies. Since the introduction of insulin analogues, insulin management has changed. This follow-up review attempts to update our earlier publication from 2009 and discusses the role of new insulin analogues and newer insulin regimens. Recognising the advent of new quality and economic initiatives both in the UK and worldwide, this paper reviews current insulin prescribing and the pros and cons of prescribing analogues in comparison to the human insulins that are now gaining more acceptance in everyday clinical practice.

Collision of Three Pandemics: The Coexistence of Cervical Cancer, HIV Infection, and Prior Tuberculosis in the Sub-Saharan Country of Botswana

Cervical cancer is the leading cause of cancer-related mortality in the developing world, where HIV and Mycobacterium tuberculosis (TB) infection are also endemic. HIV infection is independently associated with increased morbidity and mortality among women with cervical cancer. TB is believed to increase the risk of malignancies and could cause chronic inflammation in the gynecologic tract. However, the relationship between cervical cancer and TB in settings hyperendemic for HIV is unknown. We found that 18 (10%) of a cohort of 180 women with cervical cancer in Botswana had a history of TB disease. Age and HIV infection were also associated with a history of TB disease. Our data show that prior TB disease is highly prevalent among patients with cervical cancer infected with HIV. The coexistence of cervical cancer, HIV infection, and prior TB infection might be higher than expected in the general population. Prospective studies are needed to better determine the impact of the collision of these three world health epidemics.

A refined QSAR model for prediction of chemical asthma hazard

BACKGROUND

A previously developed quantitative structure-activity relationship (QSAR) model has been extern ally validated as a good predictor of chemical asthma hazard (sensitivity: 79-86%, specificity: 93-99%).

AIMS

To develop and validate a second version of this model.

METHODS

Learning dataset asthmagenic chemicals with molecular weight (MW) <1 kDa were identified from reports published in the peer-reviewed literature before the end of 2012. Control chemicals for which no reported case(s) of occupational asthma had been identified were selected at random from UK and US occupational exposure limit tables. MW banding was used in an attempt to categorically match the control group for MW distribution of the asthmagens. About 10% of chemicals in each MW category were excluded for use as an external validation set. An independent researcher utilized a logistic regression approach to compare the molecular descriptors present in asthmagens and controls. The resulting equation generated a hazard index (HI), with a value between zero and one, as an estimate of the probability that the chemical had asthmagenic potential. The HI was determined for each compound in the external validation set.

RESULTS

The model development sets comprised 99 chemical asthmagens and 204 controls. The external validation showed that using a cut-point HI of 0.39, 9/10 asthmagenic (sensitivity: 90%) and 23/24 non-asthmagenic (specificity: 96%) compounds were correctly predicted. The new QSAR model showed a better receiver operating characteristic plot than the original.

CONCLUSIONS

QSAR refinement by iteration has resulted in an improved model for the prediction of chemical asthma hazard.

Large-scale discovery of novel genetic causes of developmental disorders

Despite three decades of successful, predominantly phenotype-driven discovery of the genetic causes of monogenic disorders, up to half of children with severe developmental disorders of probable genetic origin remain without a genetic diagnosis. Particularly challenging are those disorders rare enough to have eluded recognition as a discrete clinical entity, those with highly variable clinical manifestations, and those that are difficult to distinguish from other, very similar, disorders. Here we demonstrate the power of using an unbiased genotype-driven approach to identify subsets of patients with similar disorders. By studying 1,133 children with severe, undiagnosed developmental disorders, and their parents, using a combination of exome sequencing and array-based detection of chromosomal rearrangements, we discovered 12 novel genes associated with developmental disorders. These newly implicated genes increase by 10% (from 28% to 31%) the proportion of children that could be diagnosed. Clustering of missense mutations in six of these newly implicated genes suggests that normal development is being perturbed by an activating or dominant-negative mechanism. Our findings demonstrate the value of adopting a comprehensive strategy, both genome-wide and nationwide, to elucidate the underlying causes of rare genetic disorders.

AIDS-related mycoses: the way forward

The contribution of fungal infections to the morbidity and mortality of HIV-infected individuals is largely unrecognized. A recent meeting highlighted several priorities that need to be urgently addressed, including improved epidemiological surveillance, increased availability of existing diagnostics and drugs, more training in the field of medical mycology, and better funding for research and provision of treatment, particularly in developing countries.

Acute schistosomiasis in travelers: 14 years' experience at the Hospital for Tropical Diseases, London

We report 79 cases of acute schistosomiasis. Most of these cases were young, male travelers who acquired their infection in Lake Malawi. Twelve had a normal eosinophil count at presentation and 11 had negative serology, although two had neither eosinophilia nor positive serology when first seen. Acute schistosomiasis should be considered in any febrile traveler with a history of fresh water exposure in an endemic area once malaria has been excluded.

Adipocytokine associations with insulin resistance in british South asians

Aims. Adipocytokines are implicated in the pathogenesis of type 2 diabetes and may represent identifiable precursors of metabolic disease within high-risk groups. We investigated adiponectin, leptin, and TNF- α and assessed the contribution of these molecules to insulin resistance in south Asians. Hypothesis. South Asians have adverse adipocytokine profiles which associate with an HOMA-derived insulin resistance phenotype. Methods. We measured adipocytokine concentrations in south Asians with newly diagnosed impaired glucose tolerance or Type 2 Diabetes Mellitus in a case-control study. 158 (48.5% males) volunteers aged 25-75 years with risk factors for diabetes but no known vascular or metabolic disease provided serum samples for ELISA and bioplex assays. Results. Total adiponectin concentration progressively decreased across the glucose spectrum in both sexes. A reciprocal trend in leptin concentration was observed only in south Asian men. Adiponectin but not leptin independently associated with HOMA-derived insulin resistance after logistic multivariate regression. Conclusion. Diasporic south Asian populations have an adverse adipocytokine profile which deteriorates further with glucose dysregulation. Insulin resistance is inversely associated with adiponectin independent of BMI and waist circumference in south Asians, implying that adipocytokine interplay contributes to the pathogenesis of metabolic disease in this group.

Multifactorial intervention in individuals with type 2 diabetes and microalbuminuria: the Microalbuminuria Education and Medication Optimisation (MEMO) study

AIMS

To determine whether tighter cardiovascular risk factor control with structured education in individuals with type 2 diabetes (T2DM) and microalbuminuria benefits cardiovascular risk factors.

METHODS

Participants from a multiethnic population, recruited from primary care and specialist clinics were randomised to intensive intervention with structured patient (DESMOND model) education (n=94) or usual care by own health professional (n=95).

PRIMARY OUTCOME

change in HbA1c at 18months.

SECONDARY OUTCOMES

changes in blood pressure (BP), cholesterol, albuminuria, proportion reaching risk factor targets, modelled cardiovascular risk scores.

RESULTS

Mean (SD) age and diabetes duration of participants were 61.5 (10.5) and 11.5 (9.3) years, respectively. At 18months, intensive intervention showed significant improvements in HbA1c (7.1(1.0) vs. 7.8(1.4)%, p<0.0001), systolic BP (129(16) vs. 139(17) mmHg, p<0.0001), diastolic BP (70(11) vs. 76(12) mmHg, p<0.001), total cholesterol (3.7(0.8) vs. 4.1(0.9) mmol/l, p=0.001). Moderate and severe hypoglycaemia was 11.2 vs. 29.0%; p=0.001 and 0 vs. 6.3%; p=0.07, respectively. More intensive participants achieved ≥3 risk factor targets with greater reductions in cardiovascular risk scores.

CONCLUSIONS

Intensive intervention showed greater improvements in metabolic control and cardiovascular risk profile with lower rates of moderate and severe hypoglycaemia. Intensive glycaemic interventions should be underpinned by structured education promoting self-management in T2DM.

Identification of alkaptonuria in the general population: a United Kingdom experience describing the challenges, possible solutions and persistent barriers

Progress in research into rare diseases is challenging. This paper discusses strategies to identify individuals with the rare genetic disease alkaptonuria (AKU) within the general population. Strategies used included a questionnaire survey of general practitioners, a dedicated website and patient network contact, targeted family screening and medical conference targeting. Primary care physicians of the UK were targeted by a postal survey that involved mailing 11,151 UK GPs; the response rate was 18.2%. We have identified 75 patients in the UK with AKU by the following means: postal survey (23), targeted family screening (11), patient networks and the website (41). Targeting medical conferences (AKU, rare diseases, rheumatology, clinical biochemistry, orthopaedics, general practitioners) did not lead to new identification in the UK but helped identify overseas cases. We are now aware of 626 patients worldwide including newly identified non-UK people with AKU in the following areas: Slovakia (208), the rest of Europe (including Turkey) (79), North America (including USA and Canada) (110), and the rest of the world (154). A mechanism for identifying individuals with AKU in the general population-not just in the UK but worldwide-has been established. Knowledge of patients with AKU, both in the UK and outside, is often confined to establishing their location in a particular GP practice or association with a particular medical professional. Mere identification, however, does not always lead to full engagement for epidemiological research purposes or targeting treatment since further barriers exist.

The potential impact of using glycated haemoglobin as the preferred diagnostic tool for detecting Type 2 diabetes mellitus

AIMS

There are calls to simplify the diagnosis of Type 2 diabetes mellitus (T2DM) to reduce the burden of undiagnosed disease. Glycated haemoglobin (HbA(1c)) is therefore being considered as a preferred diagnostic tool to replace the need for an oral glucose tolerance test (OGTT), considered by many as cumbersome and inconvenient. The aim of this study was to examine the potential impact of the preferred use of HbA(1c) as a diagnostic tool on the prevalence and phenotype of T2DM.

METHODS

Analysis of the Leicester Ethnic Atherosclerosis and Diabetes Risk (LEADER) cohort for previously undiagnosed individuals between 40 and 75 years of age who had OGTT, repeated if within the diabetes range, and HbA(1c) results. We compared the prevalence and phenotype of subjects with T2DM based on either HbA(1c)> or =6.5% or OGTT using 1999 World Health Organization criteria.

RESULTS

From the total population of 8696, we detected 291 (3.3%) with T2DM from using an OGTT, and 502 (5.8%) had HbA(1c)> or =6.5%. Of those diagnosed with T2DM by OGTT, 93 (1.2%) had HbA(1c) <6.5% and therefore would not have been classified as having T2DM using proposed criteria. Using HbA(1c) criteria resulted in 304 (3.5%) additional cases of T2DM, approximately doubling the prevalence. Of these 304 additional people, 172 (56.7%) had impaired glucose tolerance/impaired fasting glycaemia according to 1999 World Health Organization criteria. Using HbA(1c) criteria there was an increase of 2.2- and 1.4-fold in south Asians and white Europeans detected, respectively.

CONCLUSIONS

Within this multi-ethnic cohort, we found that introducing HbA(1c)> or =6.5% as the preferred diagnostic test to diagnose T2DM significantly increased numbers detected with T2DM; however, some people were no longer detected as having T2DM.

Anaemia in pregnancy: associations with parity, abortions and child spacing in primary healthcare clinic attendees in Trinidad and Tobago

OBJECTIVE

To determine the prevalence of anaemia in antenatal clinic attendees; to investigate the effects of parity, age, gravidity, previous abortions, child spacing and other factors on the prevalence of anaemia in pregnancy.

METHODS

This was a retrospective and cross-sectional study. Antenatal records of 2287 pregnant women attending 40 public healthcare centres from January 2000 to December 2005 in Trinidad and Tobago were used. Data pertaining to the investigated variables were recorded. The national prevalence of anaemia was calculated and chi-square tests, odds ratios and logistic regression were used to assess the relationship between anaemia and each variable.

RESULTS

The prevalence of anaemia was 15.3% (95% CI 13.4%, 16.6%). No significant difference in the prevalence of anaemia was found among the different clinics or counties. At the first haemoglobin reading, age was inversely related to the presence of anaemia, whereas gestational age at first visit was directly related. At the final haemoglobin reading, parity, gravidity, and previous spontaneous abortions were directly related to the prevalence of anaemia, while the number of visits was inversely related. Age was inversely associated to the severity of anaemia while gravidity was directly related.

CONCLUSION

The prevalence of anaemia decreased by 18.7% from 1967. Despite this positive indication, women under 24 years and those commencing antenatal care after the first trimester are still at a higher risk for developing anaemia. Early commencement of antenatal care and close monitoring of the risk groups identified should be strongly advocated.

How can structured self-management patient education improve outcomes in people with type 2 diabetes?

Type 2 diabetes (T2DM) is a long-term chronic condition that is complex to manage, with the majority of management being done by the person with diabetes outside of the clinical setting. Because of its complexities, effective self-management requires skills, confidence and the ability to make decisions and choices about treatments and lifestyle on a day-to-day basis. Equipping a person with these self-management skills is in itself challenging and it is now widely accepted that structured education is an integral part of the management of T2DM. This paper explores whether structured self-management education can improve outcomes in people with diabetes. The authors explore what self-management education is, why it is needed and then go on to examine the recent evidence from clinical trials from 2006 onwards.

New insulins and new insulin regimens: a review of their role in improving glycaemic control in patients with diabetes

Effective glycaemic control can reduce and potentially prevent the microvascular and macrovascular complications of diabetes. Insulin is the mainstay of treatment for type 1 diabetes and is indicated in patients with type 2 diabetes who do no achieve optimal glycaemic control despite the use of oral hypoglycaemic agents. The advent of the so-called "designer" insulins, the insulin analogues, has offered new opportunities in the clinical management of diabetes. This review examines the efficacy of the different analogue insulins introduced thus far and goes on to explain their pharmacodynamics and pharmacokinetics. The review also examines the different types of insulin regimen currently used in clinical practice and discusses some of the factors that influence the choice of a particular insulin regimen. Further, irrespective of the insulin regimen used, the importance of prompt initiation and ongoing titration of insulin treatment to achieve optimal glycaemic targets is emphasised.

Independent association between rate of clearance of infection and clinical outcome of HIV-associated cryptococcal meningitis: analysis of a combined cohort of 262 patients

BACKGROUND

Progress in therapy for cryptococcal meningitis has been slow because of the lack of a suitable marker of treatment response. Previously, we demonstrated the statistical power of a novel endpoint, the rate of clearance of infection, based on serial quantitative cultures of cerebrospinal fluid, to differentiate the fungicidal activity of alternative antifungal drug regimens. We hypothesized that the rate of clearance of infection should also be a clinically meaningful endpoint.

METHODS

We combined data from cohorts of patients with human immunodeficiency virus-associated cryptococcal meningitis from Thailand, South Africa, and Uganda, for whom the rate of clearance of infection was determined, and clinical and laboratory data prospectively collected, and explored the association between the rate of clearance of infection and mortality by Cox survival analyses.

RESULTS

The combined cohort comprised 262 subjects. Altered mental status at presentation, a high baseline organism load, and a slow rate of clearance of infection were independently associated with increased mortality at 2 and 10 weeks. Rate of clearance of infection was associated with antifungal drug regimen and baseline cerebrospinal fluid interferon-gamma levels.

CONCLUSIONS

The results support the use of the rate of clearance of infection or early fungicidal activity as a means to explore antifungal drug dosages and combinations in phase II studies. An increased understanding of how the factors determining outcome interrelate may help clarify opportunities for intervention.

Multiple-infection and recombination in HIV-1 within a longitudinal cohort of women

Background

Recombination between strains of HIV-1 only occurs in individuals with multiple infections, and the incidence of recombinant forms implies that multiple infection is common. Most direct studies indicate that multiple infection is rare. We determined the rate of multiple infection in a longitudinal study of 58 HIV-1 positive participants from The Women's Interagency HIV Study with a richer sampling design than previous direct studies, and we investigated the role of recombination and sampling design on estimating the multiple infection rate.

Results

40% of our sample had multiple HIV-1 infections. This rate of multiple infection is statistically consistent with previous studies once differences in sampling design are taken into account. Injection drug use significantly increased the incidence of multiple infections. In general there was rapid elimination of secondary strains to undetectable levels, but in 3 cases a superinfecting strain displaced the initial infecting strain and in two cases the strains coexisted throughout the study. All but one secondary strain was detected as an inter- and/or intra-genic recombinant. Injection drug use significantly increased the rate of observed recombinants.

Conclusion

Our multiple infection rate is consistent with rates estimated from the frequency of recombinant forms of HIV-1. The fact that our results are also consistent with previous direct studies that had reported a much lower rate illustrates the critical role of sampling design in estimating this rate. Multiple infection and recombination significantly add to the genetic diversity of HIV-1 and its evolutionary potential, and injection drug use significantly increases both.

Insulin U-500 in severe insulin resistance in type 2 diabetes mellitus

Some patients with type 2 diabetes mellitus (T2DM) are profoundly insulin resistant and require large insulin doses to achieve optimal glycaemic control. However, large volumes of subcutaneous conventional U-100 insulin can cause discomfort at the injection site, resulting in poor concordance with insulin therapy. One therapeutic option is the use of U-500 insulin, thus reducing the insulin volume by 80%. This review will address the practical issues associated with the use of U-500, clinical efficacy and safety aspects of this concentrated insulin, which has an important role in a subgroup of patients with T2DM.

Recent advances in the management of type 2 diabetes mellitus: a review

Type 2 diabetes mellitus (T2DM) is a progressive disorder caused by a combination of insulin resistance and beta cell dysfunction. It is associated with an increased and premature risk of cardiovascular disease as well as specific microvascular complications such as retinopathy, nephropathy and neuropathy. In the last 5 years new glucose lowering drugs acting on novel pathways have been developed, licensed and launched, such as the glucagon-like peptide (GLP-1) agonists (exenatide) and dipeptidyl peptidase (DPP-IV) inhibitors such as sitagliptin and vildagliptin. This review looks at these new agents in terms of their mode of action, pharmacokinetics and use in clinical practice. This review also includes new agents in the area of weight loss that may have a positive effect for glucose management-for example, rimonabant.

Insulin glargine and its role in glycaemic management of Type 2 diabetes

BACKGROUND

Insulin glargine (Lantus) was the first recombinant-DNA long-acting insulin analogue to be licensed for use in the treatment of diabetes mellitus.

OBJECTIVE

This review considers the use of insulin glargine in the treatment of type 2 diabetes (T2DM).

METHODS

Medline, Cochrane and Embase databases were searched for relevant papers from the year 2000 onwards.

RESULTS/CONCLUSION

Overall glargine provides at least equivalent glycaemic control and is associated with less hypoglycaemia, especially nocturnal hypoglycaemia owing to its 24 h peakless profile, which allows more aggressive titration to achieve glycaemic targets. Glargine has been shown to be safely initiated both individually and within a group setting and titration algorithms self-managed by patients are effective in achieving diabetes control. Despite these advantages, caution is needed as clinical guidelines do not advocate its use in all people with T2DM until clinical efficacy and cost effectiveness have been proved. However, insulin glargine is a welcome addition to the plethora of treatment options available for T2DM.

Use of finite element analysis in presurgical planning: treatment of mandibular fractures

BACKGROUND

The current clinical procedure for mandible fracture fixation is plate application. 3D reconstructions are used to validate procedures numerically preceding experimental analysis. This study outlines the methods used to reconstruct a numerical model of the mandible.

METHODS

A CT scan from a 22-year-old male patient with a healthy unfractured mandible was obtained. A 3D reconstruction was carried out using Mimics via thresholding and segmentation techniques. Boundary conditions and muscle forces were applied, and simulations were performed using ABAQUS.

RESULTS

3D reconstruction allows for precise anatomical dimensions, which can be used for further engineering analysis. Using the surgical Champy technique as an example, results showed that the mandible model returned to normal function post-plating.

CONCLUSIONS

The study shows the clinical relevance of 3D reconstructions to plan surgical procedures. Results illustrate the benefit of carrying out numerical validations as a prerequisite to experimental modelling and as a method of pre-validating surgical procedures.

A randomized controlled trial examining combinations of repaglinide, metformin and NPH insulin

AIMS

To compare combination use of repaglinide, metformin and bedtime Neutral Protamine Hagedorn (NPH) insulin with conventional approaches of insulin initiation in patients with Type 2 diabetes (T2DM).

METHODS

Eighty-two patients with T2DM with suboptimal glycaemic control on oral glucose-lowering agents were randomized to one of three treatment regimens for 4 months. Group 1 received metformin and twice daily biphasic 30/70 human insulin mixture (n = 27), group 2 metformin and bedtime NPH insulin (n = 26) and group 3 metformin, bedtime NPH insulin and mealtime repaglinide (n = 25).

RESULTS

Seventy-five patients completed the study. Baseline and end-point mean HbA1c levels fell from 9.0 +/- 1.1 to 7.9 +/- 1.1% in group 1, 10.0 +/- 2.2 to 9.2 +/- 1.4% group 2 and 10.0 +/- 1.7 to 8.1 +/- 1.5% in group 3, respectively. All groups showed improvements in HbA1c. There was no significant difference between groups in the proportions of patients experiencing hypoglycaemia (29.6, 25.0 and 16.7%, respectively; P = 0.55) or in mean weight gain (2.9, 0.7 and 2.2 kg, respectively; P = 0.06). By 4 months, insulin doses were 0.63 +/- 0.32 IU/kg in group 1, 0.58 +/- 0.21 IU/kg in group 2 and 0.37 +/- 0.22 IU/kg in group 3 (group 3 vs. groups 1 and 2: P < 0.002).

CONCLUSIONS

The approach using repaglinide, metformin and NPH insulin improved glycaemic control with a similar safety profile to conventional insulin initiation in T2DM and produced final glycaemic control similar to metformin and a twice daily biphasic insulin mixture.

Diabetes screening anxiety and beliefs

AIMS

This study assesses the impact of screening for diabetes on anxiety levels in an ethnically mixed population in the UK, and explores whether beliefs about Type 2 diabetes account for these anxiety levels.

METHODS

This cross-sectional study recruited individuals who were identified at high risk of developing diabetes through general practitioners' (GPs) lists or through public media recruitment. Participants completed an oral glucose tolerance test (OGTT). Between blood tests, participants completed the Spielberger State Anxiety Scale Short Form, the Emotional Stability Scale of the Big Five Inventory 44 and three scales from the Diabetes Illness Representations Questionnaire, revised for this study.

RESULTS

Of the 1339 who completed the OGTT and questionnaire booklet, 54% were female, with 21% from an Asian background. Forty-five per cent of participants reported little to moderate amounts of anxiety at screening (mean 35.2; sd = 11.6). There was no significant effect of family history of diabetes, ethnic group or recruitment method on anxiety. The only variable significantly associated (negatively) with anxiety was the personality trait of emotional stability. Of responders, 64% and 61% agreed that diabetes was caused by diet or hereditary factors, respectively. Only 155 individuals (12%) agreed that diabetes was serious, shortens life and causes complications.

CONCLUSIONS

The results of this study replicate that of previous studies, indicating that screening for diabetes does not induce significant anxiety. Bivariate analysis indicated that individuals who perceived diabetes to be serious, life shortening and resulting in complications had higher anxiety scores, the personality trait of emotional stability being the strongest predictor of anxiety.

Implantable device for long-term electrical stimulation of denervated muscles in rabbits

Although denervating injuries produce severe atrophic changes in mammalian skeletal muscle, a degree of functional restoration can be achieved through an intensive regime of electrical stimulation. An implantable stimulator was developed so that the long-term effects of different stimulation protocols could be compared in rabbits. The device, which is powered by two lithium thionyl chloride batteries, is small enough to be implanted in the peritoneal cavity. All stimulation parameters can be specified over a wide range, with a high degree of resolution; in addition, up to 16 periods of training (10-180 min) and rest (1-42 h) can be set in advance. The microcontroller-based device is programmed through a bidirectional radiofrequency link. Settings are entered via a user-friendly computer interface and annotated to create an individual study protocol for each animal. The stimulator has been reliable and stable in use. Proven technology and rigorous quality control has enabled 55 units to be implanted to date, for periods of up to 36 weeks, with only two device failures (at 15 and 29 weeks). Changes in the excitability of denervated skeletal muscles could be followed within individual animals. Chronaxie increased from 3.24 +/- 0.54 ms to 15.57 +/- 0.85 ms (n = 55, p < 0.0001) per phase in the 2 weeks following denervation.

Relationship between chemical structure and the occupational asthma hazard of low molecular weight organic compounds

AIMS

To investigate quantitatively, relationships between chemical structure and reported occupational asthma hazard for low molecular weight (LMW) organic compounds; to develop and validate a model linking asthma hazard with chemical substructure; and to generate mechanistic hypotheses that might explain the relationships.

METHODS

A learning dataset used 78 LMW chemical asthmagens reported in the literature before 1995, and 301 control compounds with recognised occupational exposures and hazards other than respiratory sensitisation. The chemical structures of the asthmagens and control compounds were characterised by the presence of chemical substructure fragments. Odds ratios were calculated for these fragments to determine which were associated with a likelihood of being reported as an occupational asthmagen. Logistic regression modelling was used to identify the independent contribution of these substructures. A post-1995 set of 21 asthmagens and 77 controls were selected to externally validate the model.

RESULTS

Nitrogen or oxygen containing functional groups such as isocyanate, amine, acid anhydride, and carbonyl were associated with an occupational asthma hazard, particularly when the functional group was present twice or more in the same molecule. A logistic regression model using only statistically significant independent variables for occupational asthma hazard correctly assigned 90% of the model development set. The external validation showed a sensitivity of 86% and specificity of 99%.

CONCLUSIONS

Although a wide variety of chemical structures are associated with occupational asthma, bifunctional reactivity is strongly associated with occupational asthma hazard across a range of chemical substructures. This suggests that chemical cross-linking is an important molecular mechanism leading to the development of occupational asthma. The logistic regression model is freely available on the internet and may offer a useful but inexpensive adjunct to the prediction of occupational asthma hazard.

Clinical outcomes of patients with impaired left ventricular ejection fraction undergoing autologous bone marrow transplantation: can we safely transplant patients with impaired ejection fraction?

Experience with autologous bone marrow transplantation (ABMT) in patients with impaired left ventricular ejection fraction (LVEF) or heart failure (HF) is limited. We identified 308 consecutive patients who underwent ABMT for Hodgkin's or non-Hodgkin's lymphoma at our institution (1996-2003). Patient characteristics, clinical course and overall survival were compared between patients with preserved ( > or = 50%) or impaired ( < 50%) LVEF. Of the 308 patients identified, 20 had baseline impaired LVEF (four with LVEF < or = 40%, all NYHA class I-II HF). None of the patients with post-ABMT echocardiogram had worsened LVEF (n = 7). Among the 20 patients with impaired LVEF, four patients had reversible cardiac complications post-ABMT (including worsening HF). The two deaths observed in the impaired LVEF group were both due to noncardiac causes. The 5-year survival was similar between patients with preserved and impaired LVEF (P = 0.43). Careful selection of patients with stable, mild-to-moderate HF and impaired LVEF for ABMT can achieve similar long-term survival. As medical care for HF and ABMT improves, the exclusion criteria for ABMT with regard to HF and impaired LVEF should be re-examined.