Cutaneous hyperpigmentation and familial gastrointestinal stromal tumour associated with KIT mutation.

Gastrointestinal stromal tumours (GISTs) are mesenchymal tumours arising in the gastrointestinal tract. Early detection, before metastasis occurs, is important as complete surgical excision achieves cure. Approximately 85% of GISTs are associated with mutations in the KIT gene, and although the majority of GISTs are sporadic, familial GISTs have been identified. Several families with multiple GIST tumours have also been described with various cutaneous findings including hyperpigmentation, multiple lentigines, vitiligo and urticaria pigmentosa. We discuss a 6-year-old boy who presented with an unusual pattern of hyperpigmentation in association with a family history of GIST. A causative KIT mutation was identified in DNA from the pigmented skin and from the resected GIST, and the patient was referred to the Paediatric Gastroenterology department for GIST screening. The term 'GIST cutaneous hyperpigmentation disease' has been suggested previously for the association of familial GIST with cutaneous hyperpigmentation caused by a germline KIT mutation.

Prevalence of founder mutations in the BRCA1 and BRCA2 genes among unaffected women from the Bahamas.

Population-based testing for BRCA1/2 mutations detects a high proportion of carriers not identified by cancer family history-based testing. We sought to determine whether population-based testing is an effective approach to genetic testing in the Bahamas, where 23% of women with breast cancer carry one of seven founder mutations in the BRCA1 or BRCA2 gene. We determined the prevalence of founder BRCA mutations in 1847 Bahamian women without a personal history of breast or ovarian cancer, unselected for age or family history. We found that 2.8% (20/705) of unaffected women with a family history of breast/ovarian cancer and 0.09% (1/1089) of unaffected women without a family history carry a BRCA mutation. A total of 38% of unaffected women with a known mutation in the family were found to carry the familial mutation. We previously suggested that all Bahamian women with breast or ovarian cancer be offered genetic testing. These current data suggest that additionally all unaffected Bahamian women with a family history of breast/ovarian cancer should be offered genetic testing for the founder BRCA mutations.

Vein imaging laser reduces bruising in bruise-prone botulinum toxin injected patients.

BACKGROUND: Injection-related bruising is a common complication of many injectable treatments including facial injections of botulinum toxin (BTX) for aesthetic use. OBJECTIVE: We have investigated the use of a vein imaging laser (VIL) to observe otherwise non-visible subcutaneous blood vessels in 40 patients who had a history of bruising with past BTX injections to the face during the previous 12 months. METHODS: Over a 4-month period 40 patients, who previously had developed bruising after injectable BTX to the face, were treated with further BTX to the same areas as previously, but using a VIL during the injections. Patients were evaluated for their severity of bruising. RESULTS: 40 patients out of 2400 patients had experienced bruising with a severity score total of 92 (mean per patient 2.3) with BTX injections before VIL use. On injection using the VIL 6 of the 40 patients had bruising with severity score total of 7 (mean 1.16). CONCLUSION: The use of a VIL significantly reduced the frequency and severity of bruising associated with BTX injections.

Using fNIRS to Study Working Memory of Infants in Rural Africa.

A pilot study was conducted to assess the feasibility of using fNIRS as an alternative to behavioral assessments of cognitive development with infants in rural Africa. We report preliminary results of a study looking at working memory in 12-16-month-olds and discuss the benefits and shortcomings for the potential future use of fNIRS to investigate the effects of nutritional insults and interventions in global health studies.

The laminar organization of cell types in macaque cortex and its relationship to neuronal oscillations.

The canonical microcircuit (CMC) has been hypothesized to be the fundamental unit of information processing in cortex. Each CMC unit is thought to be an interconnected column of neurons with specific connections between excitatory and inhibitory neurons across layers. Recently, we identified a conserved spectrolaminar motif of oscillatory activity across the primate cortex that may be the physiological consequence of the CMC. The spectrolaminar motif consists of local field potential (LFP) gamma-band power (40-150 Hz) peaking in superficial layers 2 and 3 and alpha/beta-band power (8-30 Hz) peaking in deep layers 5 and 6. Here, we investigate whether specific conserved cell types may produce the spectrolaminar motif. We collected laminar histological and electrophysiological data in 11 distinct cortical areas spanning the visual hierarchy: V1, V2, V3, V4, TEO, MT, MST, LIP, 8A/FEF, PMD, and LPFC (area 46), and anatomical data in DP and 7A. We stained representative slices for the three main inhibitory subtypes, Parvalbumin (PV), Calbindin (CB), and Calretinin (CR) positive neurons, as well as pyramidal cells marked with Neurogranin (NRGN). We found a conserved laminar structure of PV, CB, CR, and pyramidal cells. We also found a consistent relationship between the laminar distribution of inhibitory subtypes with power in the local field potential. PV interneuron density positively correlated with gamma (40-150 Hz) power. CR and CB density negatively correlated with alpha (8-12 Hz) and beta (13-30 Hz) oscillations. The conserved, layer-specific pattern of inhibition and excitation across layers is therefore likely the anatomical substrate of the spectrolaminar motif. Significance Statement: Neuronal oscillations emerge as an interplay between excitatory and inhibitory neurons and underlie cognitive functions and conscious states. These oscillations have distinct expression patterns across cortical layers. Does cellular anatomy enable these oscillations to emerge in specific cortical layers? We present a comprehensive analysis of the laminar distribution of the three main inhibitory cell types in primate cortex (Parvalbumin, Calbindin, and Calretinin positive) and excitatory pyramidal cells. We found a canonical relationship between the laminar anatomy and electrophysiology in 11 distinct primate areas spanning from primary visual to prefrontal cortex. The laminar anatomy explained the expression patterns of neuronal oscillations in different frequencies. Our work provides insight into the cortex-wide cellular mechanisms that generate neuronal oscillations in primates.

Microstructure and point defects in CdTe nanowires for photovoltaic applications.

Defects in Au-catalysed CdTe nanowires vapour-liquid-solid-grown on polycrystalline underlayers have been critically evaluated. Their low-temperature photoluminescence spectra were dominated by excitonic emission with rarely observed above-gap emission also being recorded. While acceptor bound exciton lines due to monovalent metallic impurities (Ag, Cu or Na) were seen, only deeper, donor-acceptor-pair emission could be attributed to the Au contamination that is expected from the catalyst. Annealing under nitrogen acted to enhance the single crystal-like PL emission, whilst oxidizing and reducing anneals of the type that is used in solar cell device processing caused it to degrade. The incidence of stacking faults, polytypes and twins was related only to the growth axes of the wires (<111> 50%, <112> 30% and <110> 20%), and was not influenced by annealing. The potential electrical activity of the point and extended defects, and the suitability of these nanowire materials (including processing steps) for solar cell applications, is discussed. Overall they have a quality that is superior to that of thin polycrystalline films, although questions remain about recombination due to Au.

Knowledge and Attitudes toward HPV and the HPV Vaccines in The Bahamas.

OBJECTIVE: High-risk types of human papillomavirus (HPV) are a necessary, albeit not sufficient, cause for cervical cancer development. In The Bahamas, cervical cancer is one of the leading causes of cancer despite screening and educational efforts. As a vaccine programme is being considered, awareness of HPV-related conditions and its vaccine needs to be measured. METHODS: This study design was cross-sectional and carried out at three clinical sites and one community in Nassau, Bahamas. All participants were over the age of 18 years and were invited to answer a (self-administered) questionnaire regarding knowledge and attitudes toward HPV and its vaccines. RESULTS: Of 399 participants, 75% were female and 23% male. About 41% had a high school education and 55.4% had some tertiary college education. Forty-six per cent had heard of HPV and 35% heard of the vaccine. The mean number of correct answers about HPV was 2.93 ± 3.17 of 10 questions, while for the vaccine, it was 1.37 ± 1.58 of five questions. Multivariable logistic regression indicated that some college education was associated with more HPV and HPV vaccine knowledge. Seventy-three per cent needed reassurance of the vaccine's safety and efficacy. Sixty-five per cent would vaccinate their daughters and 68% would vaccinate their sons if the vaccine was safe and effective. CONCLUSION: More public education is needed to increase awareness of cervical cancer and HPV-related diseases. Reassurance with respect to vaccine safety and efficacy also needs to be addressed. Since the majority would vaccinate their children, there is the potential for a national vaccination programme to succeed.

Genetic testing and screening of individuals at risk of NF2.

Genetic testing and management of the at-risk individual for neurofibromatosis type 2 (NF2) is complicated by the well-documented risk of mosaicism that causes a milder later onset more asymmetrical disease course. Risks of NF2 were derived from genetic testing of over 1000 individuals through the Manchester NF2-testing service. Individuals are at risk of NF2 or have 'potential' NF2 if they have features of the disease that fall short of diagnostic criteria or are the first-degree relative of someone with NF2 or suspected NF2. The present protocol devised for the Nationally Commissioned Group (NCG) NF2 service in England addresses the risks, genetic testing and screening protocol for individuals at risk of NF2. Screening with cranial magnetic resonance imaging is advised until the risk of NF2 falls below a pragmatic threshold of 1%. Multiple case scenarios are shown to illustrate how to use the protocol.

The current and future role of the dietetic support worker.

BACKGROUND: The role of the dietetic support worker (DSW) was developed to provide cost-effective support to dietetic services in the National Health Service (NHS). However, there is little evidence about how the role is perceived or the impact of the introduction of Agenda for Change in 2004 (a guide to pay terms and conditions for NHS staff) on role definition. The present study aimed to gather evidence from DSWs and dietitians on the current role of the DSW to help inform the future development of the role. METHODS: A questionnaire survey was conducted on DSWs and dietitians in 10 trusts in the East of England. Issues included qualifications, experience, training, satisfaction with Agenda for Change, supervision and responsibility. Themes were further explored by semi-structured telephone interviews conducted on a subsample. RESULTS: Eighteen out of 24 DSWs and 62 out of 98 dietitians responded to the questionnaire. The role of the DSW is highly valued by dietitians. Over three-quarters of DSWs and over 90% of dietitians agree that the employment of DSWs improved the working lives of dietitians. Only 50% of DSWs were happy with their Agenda for Change banding, although this did not adversely affect their job satisfaction. Both groups saw the role of the DSW becoming more specialised, despite concerns about access to appropriate training and the lack of a structured career pathway. CONCLUSIONS: This study identified issues relating to the future development of the role of the DSW from the viewpoint of DSWs and dietetic assistants.

Regulation of leucine metabolism in man: a stable isotope study.

Leucine catabolism is regulated by either of the first two degradative steps: (reversible) transamination to the keto acid or subsequent decarboxylation. A method is described to measure rates of leucine transamination, reamination, and keto acid oxidation. The method is applied directly to humans by infusing the nonradioactive tracer, L-[15N,1-13C]leucine. Leucine transamination was found to be operating several times faster than the keto acid decarboxylation and to be of equal magnitude in adult human males under two different dietary conditions, postabsorptive and fed. These results indicate that decarboxylation, not transamination, is the rate-limiting step in normal human leucine metabolism.

Contribution of molecular analyses in diagnosing Marfan syndrome and type I fibrillinopathies: an international study of 1009 probands.

BACKGROUND: The diagnosis of Marfan syndrome (MFS) is usually initially based on clinical criteria according to the number of major and minor systems affected following international nosology. The number of FBN1 mutation carriers, at risk of aortic complications who would not be properly diagnosed based only on clinical grounds, is of growing importance owing to the increased availability of molecular screening. The aim of the study was to identify patients who should be considered for FBN1 mutation screening. METHODS: Our international series included 1009 probands with a known FBN1 mutation. Patients were classified as either fulfilling or not fulfilling "clinical" criteria. In patients with unfulfilled "clinical" criteria, we evaluated the percentage of additional patients who became positive for international criteria when the FBN1 mutation was considered. The aortic risk was evaluated and compared in patients fulfilling or not fulfilling the "clinical" international criteria. RESULTS: Diagnosis of MFS was possible on clinical grounds in 79% of the adults, whereas 90% fulfilled the international criteria when including the FBN1 mutation. Corresponding figures for children were 56% and 85%, respectively. Aortic dilatation occurred later in adults with unfulfilled "clinical criteria" when compared to the Marfan syndrome group (44% vs 73% at 40 years, p<0.001), but the lifelong risk for ascending aortic dissection or surgery was not significantly different in both groups. CONCLUSIONS: Because of its implications for aortic follow-up, FBN1 molecular analysis is recommended in newly suspected MFS when two systems are involved with at least one major system affected. This is of utmost importance in patients without aortic dilatation and in children.

Neural Spike Train Synchronisation Indices: Definitions, Interpretations and Applications.

A comparison of previously defined spike train syncrhonization indices is undertaken within a stochastic point process framework. The second order cumulant density (covariance density) is shown to be common to all the indices. Simulation studies were used to investigate the sampling variability of a single index based on the second order cumulant. The simulations used a paired motoneurone model and a paired regular spiking cortical neurone model. The sampling variability of spike trains generated under identical conditions from the paired motoneurone model varied from 50% { 160% of the estimated value. On theoretical grounds, and on the basis of simulated data a rate dependence is present in all synchronization indices. The application of coherence and pooled coherence estimates to the issue of synchronization indices is considered. This alternative frequency domain approach allows an arbitrary number of spike train pairs to be evaluated for statistically significant differences, and combined into a single population measure. The pooled coherence framework allows pooled time domain measures to be derived, application of this to the simulated data is illustrated. Data from the cortical neurone model is generated over a wide range of firing rates (1 - 250 spikes/sec). The pooled coherence framework correctly characterizes the sampling variability as not significant over this wide operating range. The broader applicability of this approach to multi electrode array data is briefly discussed.

African-Caribbean Cancer Consortium Scientific and Training Conference 2017.

The sixth International African-Caribbean Cancer Consortium (AC3) Conference was held 6-9 October 2017 in Miami, Florida, U.S.A. The conference was open to all researchers, trainees, clinical and public health professionals, and community members, and served as an international hub for the United States, the Caribbean, and Africa. Sessions included AC3 collaboration meetings, cancer surveillance and research skills training workshops, and a community cancer prevention conference.

Early life programming of hemispheric lateralization and synchronization in the adult medial prefrontal cortex.

Neonatal maternal separation (MS) in the rat increases the vulnerability to stressors later in life. In contrast, brief handling (H) in early life confers resilience to stressors in adulthood. Early life programming of stress reactivity may involve the medial prefrontal cortex (mPFC), a region which modulates various stress responses. Moreover, hemispheric specialization in mPFC may mediate adaptive coping responses to stress. In the present study, neuronal activity was examined simultaneously in left and right mPFC in adult rats previously subjected to MS, H or animal facility rearing (AFR). In vivo electrophysiology, under isoflurane anesthesia, was used to conduct acute recordings of unit and local field potential (LFP) activity in response to systemic administration of N-methyl-beta-carboline-3-carboxamide (FG-7142), a benzodiazepine receptor partial inverse agonist which mimics various stress responses. MS decreased basal unit activity selectively in right mPFC. Basal LFP activity was reduced with MS in left and right mPFC, compared to AFR and H, respectively. Hemispheric synchronization of basal LFP activity was also attenuated by MS at lower frequencies. FG-7142 elicited lateralized effects on mPFC activity with different early rearing conditions. Activity in left mPFC was greater with AFR and MS (AFR>MS), whereas activity was predominantly greater with H in right mPFC. Finally, compared to AFR, MS reduced and H enhanced hemispheric synchronization of LFP activity with FG-7142 treatment in a dose-dependent manner. These results indicate that functionally-relevant alterations in mPFC GABA transmission are programmed by the early rearing environment in a hemisphere-dependent manner. These findings may model the hemispheric specialization of mPFC function thought to mediate adaptive coping responses to stressors. They also suggest the possibility that early environmental programming of hemispheric functional coupling in mPFC is involved in conferring vulnerability or resilience to stressors later in life.

Significant phenylalanine hydroxylation in vivo in patients with classical phenylketonuria.

Indirect measurements have previously suggested that patients with classical phenylketonuria (PKU) do not convert significant amounts of phenylalanine to tyrosine. Low-dose continuous infusion techniques employing [2H5]phenylalanine and [2H2]tyrosine were used to quantitate in vivo phenylalanine hydroxylation in 10 subjects with classical phenylketonuria, 2 with hyperphenylalaninemia (HPA), and 7 controls. Plasma phenylalanine concentration ranged from 523 to 1,540 mumols/liter in PKU, 402 to 533 in HPA, and 49 to 54 in controls. Subjects with classical PKU hydroxylated mean +/- SD 4.8 +/- 2.2 mumols/kg per h (range 0.9-8.4) of phenylalanine to tyrosine and those with HPA 4.4 and 5.3, respectively. These rates were substantial in comparison with those in controls (6.3 +/- 1.6, 3.2-8.2). The significant hydroxylation in PKU and HPA subjects is likely to result from induction of activity of tyrosine hydroxylase towards phenylalanine by the greatly elevated phenylalanine concentration. The presence of such activity in PKU suggests that therapy aimed at promotion of this usually latent hydroxylating capacity may be a future alternative to dietary treatment of PKU.

Effect of beta-hydroxybutyrate on whole-body leucine kinetics and fractional mixed skeletal muscle protein synthesis in humans.

Because intravenous infusion of beta-hydroxybutyrate (beta-OHB) has been reported to decrease urinary nitrogen excretion, we investigated in vivo metabolism of leucine, an essential amino acid, using L-[1-13C]leucine as a tracer during beta-OHB infusion. Leucine flux during beta-OHB infusion did not differ from leucine flux during normal saline infusion in nine normal subjects, whereas leucine oxidation decreased 18-41% (mean = 30%) from 18.1 +/- 1.1 mumol.kg-1.h-1 (P less than 0.01), and incorporation of leucine into skeletal muscle protein increased 5-17% (mean = 10%) from 0.048 + 0.003%/h (P less than 0.02). Since blood pH during beta-OHB infusion was higher than the pH during saline infusion, we performed separate experiments to study the effect of increased blood pH on leucine kinetics by infusing sodium bicarbonate intravenously. Blood pH during sodium bicarbonate infusion was similar to that observed during the beta-OHB infusion, but bicarbonate infusion had no effect on leucine flux or leucine oxidation. We conclude that beta-OHB decreases leucine oxidation and promotes protein synthesis in human beings.

On the use of low-cost computer peripherals for the assessment of motor dysfunction in Parkinson's disease--quantification of bradykinesia using target tracking tasks.

The potential of computer games peripherals to measure the motor dysfunction in Parkinson's diseases is assessed. Of particular interest is the quantification of bradykinesia. Previous studies used modified or custom haptic interfaces, here an unmodified force feedback joystick and steering wheel are used with a laptop. During testing an on screen cursor moves in response to movements of the peripheral, the user has to track a continuously moving target (pursuit tracking), or move to a predetermined target (step tracking). All tasks use movement in the horizontal axis, allowing use of joystick or steering wheel. Two pursuit tracking tasks are evaluated, pseudo random movement, and a swept frequency task. Two step tracking tasks are evaluated, movement between two or between two of five fixed targets. Thirteen patients and five controls took part on a weekly basis. Patients were assessed for bradykinesia at each session using standard clinical measures. A range of quantitative measures was developed to allow comparison between and within patients and controls using analysis of variance (ANOVA). Both peripherals are capable of discriminating between controls and patients, and between patients with different levels of bradykinesia. Recommendations for test procedures and peripherals are given.

Temporal sub units in dendritic trees.

This simulation study examines the possibility that dendritic sub units can be defined according to temporal aspects in the timing of populations of synaptic inputs. A two cell model with passive dendritic trees is used, which is subject to both common and independent synaptic inputs, the presence of common synaptic input results in a tendency for correlated firing in the two cell model. The strength of this correlation is used to measure the efficacy of the common synaptic inputs in modulating the output discharge of each neurone. Our results suggest that a small fraction of the total synaptic input can effectively modulate the timing of output spikes, this phenomenon is not dependent on the physical location of the inputs on the dendritic tree. This phenomenon depends on the presence of temporal correlation between the pre-synaptic spike trains that provide the common input. We propose to refer to these as temporal sub units.

Cortical specialisation to social stimuli from the first days to the second year of life: A rural Gambian cohort.

Brain and nervous system development in human infants during the first 1000days (conception to two years of age) is critical, and compromised development during this time (such as from under nutrition or poverty) can have life-long effects on physical growth and cognitive function. Cortical mapping of cognitive function during infancy is poorly understood in resource-poor settings due to the lack of transportable and low-cost neuroimaging methods. Having established a signature cortical response to social versus non-social visual and auditory stimuli in infants from 4 to 6 months of age in the UK, here we apply this functional Near Infrared Spectroscopy (fNIRS) paradigm to investigate social responses in infants from the first postnatal days to the second year of life in two contrasting environments: rural Gambian and urban UK. Results reveal robust, localized, socially selective brain responses from 9 to 24 months of life to both the visual and auditory stimuli. In contrast at 0-2 months of age infants exhibit non-social auditory selectivity, an effect that persists until 4-8 months when we observe a transition to greater social stimulus selectivity. These findings reveal a robust developmental curve of cortical specialisation over the first two years of life.

Experiences and views of specialist registrars in geriatric medicine on 'do not attempt resuscitation' decisions: a sea of uncertainty?

BACKGROUND: Recent cultural changes place doctors under increasing pressure to work with their patients to reach decisions about end-of-life care. AIM: To survey the experience, practice and opinions of specialist registrars (SPRs) in geriatric medicine regarding 'do not attempt resuscitation' (DNAR) decisions. DESIGN: Postal questionnaire survey. METHODS: A questionnaire was mailed to all members registered as trainees (n = 408) with the British Geriatrics Society in November 2003; a reminder was sent nine weeks later. Responses were analysed using both quantitative and qualitative (thematic) approaches. RESULTS: Response rate was 62% (251/408), of whom 235 were still SpRs. Respondents played a major role in DNAR decision-making in their day-to-day clinical practice. Over a third of respondents did not feel that locally available guidelines were helpful. More than half sometimes disagreed with their consultants' decision, and a fifth were concerned about the possibility of complaints regarding the decisions they made. The majority felt uncomfortable discussing the issue with the patient, and were more likely to discuss the issue with relatives than with patients. DISCUSSION: Further support and training may improve confidence and positive experiences in relation to DNAR decision-making among training-grade doctors in the UK.