Experience on postmortem minimally invasive tissue sampling to ascertain the cause of death determination in South African children: A case for implementing as standard of care

Determining the death burden for prioritising public health interventions necessitates detailed data on the causal pathways to death. Postmortem minimally invasive tissue sampling (MITS), incorporating histology, molecular and microbial culture diagnostics, enhances cause-of-death attribution, particularly for infectious deaths. MITS proves a valid alternative to full diagnostic autopsies, especially in low- and middle-income countries. In Soweto, South Africa (SA), the Child Health and Mortality Prevention Surveillance (CHAMPS) programme has delineated over 1 000 child and stillbirth deaths since 2017. This SA CHAMPS site supports advocating for the use of postmortem MITS as routine practice, for more granular insights into under-5 mortality causes. This knowledge is crucial for SA's pursuit of Sustainable Development Goal 3.2, targeting reduced neonatal and under-5 mortality rates. This commentary explores the public health advantages and ethicolegal considerations surrounding implementing MITS as standard of care for stillbirths, neonatal and paediatric deaths in SA. Furthermore, based on the data from CHAMPS, we present three pragmatic algorithmic approaches to the wide array of testing options for cost-effectiveness and scalability of postmortem MITS in South African state facilities.

Childhood-Onset Lupus Nephritis in the Childhood Arthritis and Rheumatology Research Alliance Registry: Short-Term Kidney Status and Variation in Care

OBJECTIVE

The goal was to characterize short-term kidney status and describe variation in early care utilization in a multicenter cohort of patients with childhood-onset systemic lupus erythematosus (cSLE) and nephritis.

METHODS

We analyzed previously collected prospective data from North American patients with cSLE with kidney biopsy-proven nephritis enrolled in the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Registry from March 2017 through December 2019. We determined the proportion of patients with abnormal kidney status at the most recent registry visit and applied generalized linear mixed models to identify associated factors. We also calculated frequency of medication use, both during induction and ever recorded.

RESULTS

We identified 222 patients with kidney biopsy-proven nephritis, with 64% class III/IV nephritis on initial biopsy. At the most recent registry visit at median (interquartile range) of 17 (8-29) months from initial kidney biopsy, 58 of 106 patients (55%) with available data had abnormal kidney status. This finding was associated with male sex (odds ratio [OR] 3.88, 95% confidence interval [95% CI] 1.21-12.46) and age at cSLE diagnosis (OR 1.23, 95% CI 1.01-1.49). Patients with class IV nephritis were more likely than class III to receive cyclophosphamide and rituximab during induction. There was substantial variation in mycophenolate, cyclophosphamide, and rituximab ever use patterns across rheumatology centers.

CONCLUSION

In this cohort with predominately class III/IV nephritis, male sex and older age at cSLE diagnosis were associated with abnormal short-term kidney status. We also observed substantial variation in contemporary medication use for pediatric lupus nephritis between pediatric rheumatology centers. Additional studies are needed to better understand the impact of this variation on long-term kidney outcomes.

COVID-19 infection and maternal morbidity in critical care units in Scotland: a national cohort study

BACKGROUND

Previous research has shown that, in comparison with non-pregnant women of reproductive age, pregnant women with COVID-19 are more likely to be admitted to critical care, receive invasive ventilation, and die. At present there are limited data in relation to outcomes and healthcare utilisation following hospital discharge of pregnant and recently pregnant women admitted to critical care.

METHODS

A national cohort study of pregnant and recently pregnant women who were admitted to critical care in Scotland with confirmed or suspected COVID-19. We examined hospital outcomes as well as hospital re-admission rates.

RESULTS

Between March 2020 and March 2022, 75 pregnant or recently pregnant women with laboratory-confirmed COVID-19 were admitted to 24 Intensive Care Units across Scotland. Almost two thirds (n=49, 65%) were from the most deprived socio-economic areas. Complete 90-day acute hospital re-admission data were available for 74 (99%) patients. Nine (12%) women required an emergency non-obstetric hospital re-admission within 90 days. Less than 5% of the cohort had received any form of vaccination.

CONCLUSIONS

This national cohort study has demonstrated that pregnant or recently pregnant women admitted to critical care with COVID-19 were more likely to reside in areas of socio-economic deprivation, and fewer than 5% of the cohort had received any form of vaccination. More targeted public health campaigning across the socio-economic gradient is urgently required.

Intraarticular steroids as DMARD-sparing agents for juvenile idiopathic arthritis flares: Analysis of the Childhood Arthritis and Rheumatology Research Alliance Registry

BACKGROUND

Children with juvenile idiopathic arthritis (JIA) who achieve a drug free remission often experience a flare of their disease requiring either intraarticular steroids (IAS) or systemic treatment with disease modifying anti-rheumatic drugs (DMARDs). IAS offer an opportunity to recapture disease control and avoid exposure to side effects from systemic immunosuppression. We examined a cohort of patients treated with IAS after drug free remission and report the probability of restarting systemic treatment within 12 months.

METHODS

We analyzed a cohort of patients from the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Registry who received IAS for a flare after a period of drug free remission. Historical factors and clinical characteristics and of the patients including data obtained at the time of treatment were analyzed.

RESULTS

We identified 46 patients who met the inclusion criteria. Of those with follow up data available 49% had restarted systemic treatment 6 months after IAS injection and 70% had restarted systemic treatment at 12 months. The proportion of patients with prior use of a biologic DMARD was the only factor that differed between patients who restarted systemic treatment those who did not, both at 6 months (79% vs 35%, p < 0.01) and 12 months (81% vs 33%, p < 0.05).

CONCLUSION

While IAS are an option for all patients who flare after drug free remission, it may not prevent the need to restart systemic treatment. Prior use of a biologic DMARD may predict lack of success for IAS. Those who previously received methotrexate only, on the other hand, are excellent candidates for IAS.

Severe maternal morbidity in Scotland

Using a cohort study design, we analysed 17 diagnoses and 9 interventions (including critical care admission) as a composite measure of severe maternal morbidity for pregnancies recorded over 14 years in Scotland. There were 762,918 pregnancies, of which 7947 (10 in 1000 pregnancies) recorded 9345 severe maternal morbidity events, 2802 episodes of puerperal sepsis being the most common (30%). Severe maternal morbidity incidence increased from 9 in 1000 pregnancies in 2012 to 17 in 1000 pregnancies in 2018, due in part to puerperal sepsis recording. The odds ratio (95%CI) for severe maternal morbidity was higher for: older women, for instance 1.22 (1.13-1.33) for women aged 35-39 years and 1.44 (1.27-1.63) for women aged > 40 years compared with those aged 25-29 years; obese women, for instance 1.13 (1.06-1.21) for BMI 30-40 kg.m-2 and 1.32 (1.15-1.51) for BMI > 40 kg.m-2 compared with BMI 18.5-24.9 kg.m-2 ; multiple pregnancy, 2.39 (2.09-2.74); and previous caesarean delivery, 1.52 (1.40-1.65). The median (IQR [range]) hospital stay was 3 (2-5 [1-8]) days with severe maternal morbidity and 2 (1-3 [1-5]) days without. Forty-one women died during pregnancy or up to 42 days after delivery, representing mortality rates per 100,000 pregnancies of about 365 with severe maternal morbidity and 1.6 without. There were 1449 women admitted to critical care, 807 (58%) for mechanical ventilation or support of at least two organs. We recorded an incidence of severe maternal morbidity higher than previously published, possibly because sepsis was coded inaccurately in our databases. Further research may determine the value of this composite measure of severe maternal morbidity.

Social determinants of health influence disease activity and functional disability in Polyarticular Juvenile Idiopathic Arthritis

BACKGROUND

Social determinants of health (SDH) greatly influence outcomes during the first year of treatment in rheumatoid arthritis, a disease similar to polyarticular juvenile idiopathic arthritis (pJIA). We investigated the correlation of community poverty level and other SDH with the persistence of moderate to severe disease activity and functional disability over the first year of treatment in pJIA patients enrolled in the Childhood Arthritis and Rheumatology Research Alliance Registry.

METHODS

In this cohort study, unadjusted and adjusted generalized linear mixed effects models analyzed the effect of community poverty and other SDH on disease activity, using the clinical Juvenile Arthritis Disease Activity Score-10, and disability, using the Child Health Assessment Questionnaire, measured at baseline, 6, and 12 months.

RESULTS

One thousand six hundred eighty-four patients were identified. High community poverty (≥20% living below the federal poverty level) was associated with increased odds of functional disability (OR 1.82, 95% CI 1.28-2.60) but was not statistically significant after adjustment (aOR 1.23, 95% CI 0.81-1.86) and was not associated with increased disease activity. Non-white race/ethnicity was associated with higher disease activity (aOR 2.48, 95% CI: 1.41-4.36). Lower self-reported household income was associated with higher disease activity and persistent functional disability. Public insurance (aOR 1.56, 95% CI 1.06-2.29) and low family education (aOR 1.89, 95% CI 1.14-3.12) was associated with persistent functional disability.

CONCLUSION

High community poverty level was associated with persistent functional disability in unadjusted analysis but not with persistent moderate to high disease activity. Race/ethnicity and other SDH were associated with persistent disease activity and functional disability.

Human milk oligosaccharide categories define the microbiota composition in human colostrum

Human milk oligosaccharides (HMOs) are structurally diverse unconjugated glycans with a composition unique to each lactating mother. While HMOs have been shown to have an impact on the development of infant gut microbiota, it is not well known if HMOs also already affect milk microbial composition. To address this question, we analysed eleven colostrum samples for HMO content by high-pressure liquid chromatography and microbiota composition by quantitative PCR. Higher total HMO concentration was associated with higher counts of Bifidobacterium spp. (ρ=0.63, P=0.036). A distinctive effect was seen when comparing different HMO groups: positive correlations were observed between sialylated HMOs and Bifidobacterium breve (ρ=0.84, P=0.001), and non-fucosylated/non-sialylated HMOs and Bifidobacterium longum group (ρ=0.65, P=0.030). In addition to associations between HMOs and bifidobacteria, positive correlations were observed between fucosylated HMOs and Akkermansia muciniphila (ρ=0.70, P=0.017), and between fucosylated/sialylated HMOs and Staphylococcus aureus (ρ=0.75, P=0.007). Our results suggest that the characterised HMOs have an effect on specific microbial groups in human milk. Both oligosaccharides and microbes provide a concise inoculum for the compositional development of the infant gut microbiota.

In vitro susceptibility of Clostridium difficile to SMT19969 and comparators, as well as the killing kinetics and post-antibiotic effects of SMT19969 and comparators against C. difficile

OBJECTIVES

SMT19969 is a novel antimicrobial under clinical development for the treatment of Clostridium difficile infection (CDI). The objective was to determine the comparative susceptibility of 82 C. difficile clinical isolates (which included ribotype 027 isolates and isolates with reduced metronidazole susceptibility) to SMT19969, fidaxomicin, vancomycin and metronidazole and to determine the killing kinetics and post-antibiotic effects of SMT19969, fidaxomicin and vancomycin against C. difficile.

METHODS

MICs were determined by agar incorporation. Killing kinetics and post-antibiotic effects were determined against C. difficile BI1, 630 and 5325 (ribotypes 027, 012 and 078, respectively).

RESULTS

SMT19969 showed potent inhibition of C. difficile (MIC90=0.125 mg/L) and was markedly more active than either metronidazole (MIC90 = 8 mg/L) or vancomycin (MIC90 = 2 mg/L). There were no differences in susceptibility to SMT19969 between different ribotypes. Fidaxomicin was typically one doubling dilution more active than SMT19969 and both agents maintained activity against isolates with reduced susceptibility to metronidazole. In addition, SMT19969 was bactericidal against the C. difficile strains tested, with reductions in viable counts to below the limit of detection by 24 h post-inoculation. Vancomycin was bacteriostatic against all three strains. Fidaxomicin was bactericidal although reduced killing was observed at concentrations <20 × MIC against C. difficile BI1 (ribotype 027) compared with other strains tested.

CONCLUSIONS

These data demonstrate that SMT19969 is associated with potent and bactericidal activity against the strains tested and support further investigation of SMT19969 as potential therapy for CDI.

The Emotional Self-Efficacy Scale

Emotional self-efficacy (ESE) is an important aspect of emotional functioning, with current measures for children and adolescents focused on the measurement of self-beliefs in relation to the management of emotions. In the present study, we report the psychometric properties of the first adaptation of the Emotional Self-Efficacy Scale for youth (Youth-ESES) that measures additional aspects of ESE, such as perceiving and understanding emotions and helping others modulate their emotions. Participants were 192 young adolescents aged 11 to 13 years from a U.K. state school. They completed the Youth-ESES and measures of ability emotional intelligence (EI) and cognitive ability. Results support the same four-factor structure that has been previously documented using the adult version of the ESES, with the four subscales being largely independent from cognitive ability and only moderately related to ability EI. However, the four subscales were less differentiated in the present study compared with adult data previously published, suggesting that there is a strong general factor underlying young adolescents’ ESE scores. Overall, the results suggest that the adapted Youth-ESES can be reliably used with youth, and that confidence in how a young person feels about his or her emotional functioning remains distinct from emotional skill.

DOC-MEK: a double-blind randomized phase II trial of docetaxel with or without selumetinib in wild-type BRAF advanced melanoma

BACKGROUND

Treatment options for wild-type BRAF melanoma patients remain limited. Selumetinib, a MEK 1/2 inhibitor, suppresses pERK levels independent of BRAF and NRAS mutation status, and combination with docetaxel has demonstrated synergy in xenograft models. The aim of this study was to assess the efficacy and safety of selumetinib plus docetaxel as first-line treatment in patients with wild-type BRAF advanced melanoma.

PATIENTS AND METHODS

In this double-blind multicentre phase II trial patients with wild-type BRAF melanoma were randomized (1:1) to docetaxel with selumetinib or placebo. Docetaxel 75 mg/m(2) was administered intravenously every 3 weeks up to six cycles. Selumetinib 75 mg or placebo was given orally twice daily until disease progression or unacceptable toxicity. The primary end point was progression-free survival (PFS). Tumour NRAS mutation status was analysed retrospectively and correlated with treatment outcomes.

RESULTS

Eighty-three patients were randomized to docetaxel plus selumetinib (n = 41) or docetaxel plus placebo (n = 42). The PFS hazard ratio (HR) (selumetinib:placebo) was 0.75 [90% confidence interval (CI) 0.50-1.14; P = 0.130], with a median PFS of 4.23 months (90% CI 3.63-6.90) for docetaxel plus selumetinib and 3.93 months (90% CI 2.07-4.16) for docetaxel alone. There was no significant difference in overall survival. The objective response rate was 32% with selumetinib versus 14% with placebo (P = 0.059). In a retrospective subset analysis, NRAS mutation status did not affect significantly upon clinical outcomes in either arm. The combination of docetaxel and selumetinib could be administered effectively to patients with metastatic melanoma, although the combination was less well tolerated than docetaxel alone.

CONCLUSIONS

The combination of docetaxel with selumetinib showed no significant improvement in PFS compared with docetaxel alone, although more patients showed a response to combination therapy. We found no evidence to support using tumour NRAS mutation as a basis for selecting patients for combined MEK inhibitor and chemotherapy.

CLINICAL TRIAL

DOC-MEK (EudraCT no: 2009-018153-23).

Sulfidation of silver nanoparticles decreases Escherichia coli growth inhibition

Sulfidation of metallic nanoparticles such as silver nanoparticles (AgNPs) released to the environment may be an important detoxification mechanism. Two types of AgNPs-an engineered polydisperse and aggregated AgNP powder, and a laboratory-synthesized, relatively monodisperse AgNP aqueous dispersion-were studied. The particles were sulfidized to varying degrees and characterized to determine the effect of initial AgNP polydispersity and aggregation state on AgNP sulfidation, and then exposed to Escherichia coli to determine if the degree of sulfidation of pristine AgNPs affects growth inhibition of bacteria. The extent of sulfidation was found to depend on the HS(-)/Ag ratio. However, for the same reaction times, the more monodisperse particles were fully transformed to Ag(2)S, and the polydisperse, aggregated particles were not fully sulfidized, thus preserving the toxic potential of Ag(0) in the aggregates. A higher Ag(2)S:Ag(0) ratio in the sulfidized nanoparticles resulted in less growth inhibition of E. coli over 6 h of exposure. These results suggest that the initial properties of AgNPs can affect sulfidation products, which in turn affect microbial growth inhibition, and that these properties should be considered in assessing the environmental impact of AgNPs.

Preferences for steaming of vegetables

BACKGROUND

Steaming retains vitamins and phytochemicals in vegetables better than boiling; thus, it is important to promote this cooking method. The present study aimed to determine what vegetable would be best to use in a campaign to promote steaming.

METHODS

Carrots, broccoli and green cabbage were boiled, steamed or microwave steamed. Untrained assessors (n = 50) evaluated the sensory properties of appearance, texture, taste and overall acceptability using a hedonic rating test on a scale from 1-9. Average scores for overall acceptability were calculated for each type of cooking according to the assessors' usual cooking method.

RESULTS

For all features, steaming and microwave steaming were rated significantly higher than boiling for broccoli (for acceptability 6.2 and 7.1 versus 5.1; P < 0.001), whereas carrots were similarly considered better for flavour and overall acceptability. Generally, cabbage was rated lower for all features, with no differences amongst the cooking methods (4.9-5.2 for acceptability). Only two of twenty-one subjects who usually boil vegetables preferred the boiled vegetables in the present study.

CONCLUSIONS

Generally, steaming and microwave steaming were preferred for certain vegetables, even by those who normally boil them. Barriers to change need to be considered when planning the promotion of steaming as a regular method of cooking vegetables, although it may be more convincing to use vegetables such as broccoli that are perceived as being most acceptable when steamed.

Dietary fat and cecal microbial activity in the rat

Weanling rats were fed low-fat (1% w/w safflower oil) or high-fat (1% w/w safflower oil plus 35% w/w beef fat or cocoa butter) diets for 30 days, and the activities of five cecal microbial enzymes were determined. When compared with the low-fat diet, beef fat significantly increased total cecal beta-glucuronidase activity, but cocoa butter, with a similar fatty acid composition, did not. Both high-fat diets significantly decreased total cecal azoreductase, beta-glucosidase, and nitrate reductase activities, but neither significantly affected urease activity. When expressed as specific activities (per 10(11) bacteria), cocoa butter decreased azoreductase, and beef fat caused increases of beta-glucuronidase and urease. Beef fat, but not cocoa butter, significantly reduced cecal bacterial numbers when compared to the low-fat diet. Both high-fat diets led to equivalent reductions in the proportion of aerobic bacteria.

Systematic review of randomized controlled trials of low-carbohydrate vs. low-fat/low-calorie diets in the management of obesity and its comorbidities

There are few studies comparing the effects of low-carbohydrate/high-protein diets with low-fat/high-carbohydrate diets for obesity and cardiovascular disease risk. This systematic review focuses on randomized controlled trials of low-carbohydrate diets compared with low-fat/low-calorie diets. Studies conducted in adult populations with mean or median body mass index of > or =28 kg m(-2) were included. Thirteen electronic databases were searched and randomized controlled trials from January 2000 to March 2007 were evaluated. Trials were included if they lasted at least 6 months and assessed the weight-loss effects of low-carbohydrate diets against low-fat/low-calorie diets. For each study, data were abstracted and checked by two researchers prior to electronic data entry. The computer program Review Manager 4.2.2 was used for the data analysis. Thirteen articles met the inclusion criteria. There were significant differences between the groups for weight, high-density lipoprotein cholesterol, triacylglycerols and systolic blood pressure, favouring the low-carbohydrate diet. There was a higher attrition rate in the low-fat compared with the low-carbohydrate groups suggesting a patient preference for a low-carbohydrate/high-protein approach as opposed to the Public Health preference of a low-fat/high-carbohydrate diet. Evidence from this systematic review demonstrates that low-carbohydrate/high-protein diets are more effective at 6 months and are as effective, if not more, as low-fat diets in reducing weight and cardiovascular disease risk up to 1 year. More evidence and longer-term studies are needed to assess the long-term cardiovascular benefits from the weight loss achieved using these diets.

Use of Cryopreserved Cells for Enabling Greater Flexibility in Compound Profiling

Measurement of intracellular calcium release following agonist challenge within cells expressing the relevant membrane protein is a commonly used format to derive structure-activity relationship (SAR) data within a compound profiling assay. The Fluorometric Imaging Plate Reader (FLIPR) has become the gold standard for this purpose. FLIPR traditionally uses cells that are maintained in continuous culture for compound profiling of iterative chemistry campaigns. This supply dictates that assays can only be run on 4 of 5 weekdays, or alternative cell culture machinery is required such that plating can occur remotely at the weekend. The data reported here demonstrate that high-quality compound profiling data can be generated from the use of cryopreserved cells and that these cells can also be plated at various densities to generate equivalent data between 24 and 72 h post-plating. Hence, the authors report a method that allows data generation throughout the week and without the requirement of highly automated cell culture or continuous culture. ( Journal of Biomolecular Screening 2008:354-362)

Equine multinodular pulmonary fibrosis: a newly recognized herpesvirus-associated fibrotic lung disease

Pulmonary fibrosis and interstitial lung disease are poorly understood in horses; the causes of such conditions are rarely identified. Equine herpesvirus 5 (EHV-5) is a gamma-herpesvirus of horses that has not been associated with disease in horses. Pathologic and virologic findings from 24 horses with progressive nodular fibrotic lung disease associated with EHV-5 infection are described and compared with 23 age-matched control animals. Gross lesions consisted of multiple nodules of fibrosis throughout the lungs. Histologically, there was marked interstitial fibrosis, often with preservation of an "alveolar-like" architecture, lined by cuboidal epithelial cells. The airways contained primarily neutrophils and macrophages. Rare macrophages contained large eosinophilic intranuclear viral inclusion bodies; similar inclusion bodies were also found cytologically. The inclusions were identified as herpesviral-like particles by transmission electron microscopy in a single horse. In situ hybridization was used to detect EHV-5 nucleic acids within occasional macrophage nuclei. With polymerase chain reaction (PCR), the herpesviral DNA polymerase gene was detected in 19/24 (79.2%) of affected horses and 2/23 (8.7%) of the control horses. Virus genera-specific PCR was used to detect EHV-5 in all of the affected horses and none of the control horses. EHV-2 was detected in 8/24 (33.3%) of affected horses and 1/9 (11.1%) of the control horses. This disease has not been reported before, and the authors propose that based upon the characteristic gross and histologic findings, the disease be known as equine multinodular pulmonary fibrosis. Further, we propose that this newly described disease develops in association with infection by the equine gamma-herpesvirus, EHV-5.

Orphan seven transmembrane receptor screening

Drug discovery has successfully exploited the superfamily of seven transmembrane receptors (7TMR), with over 35% of clinically marketed drugs targeting them. However, it is clear that there remains an undefined potential within this protein family for successful drugs of the future. The human genome sequencing project identified approximately 720 genes that belong to the 7TMR superfamily. Around half of these genes encode sensory receptors, while the other half are potential drug targets. Natural ligands have been identified for approximately 215 of these, leaving 155 receptors classified as orphan 7TMRs having no known ligand. Deorphanisation of these receptors by identification of natural ligands has been the traditional method enabling target validation by use of these ligands as tools to define biological relevance and disease association. Such ligands have been paired with their cognate receptor experimentally by screening of small molecule and peptide ligands, reverse pharmacology and the use of bioinformatics to predict candidate ligands. In this manuscript, we review the methodologies developed for the identification of ligands at orphan 7TMRs and exemplify these with case studies.

Peliod hepatocellular carcinoma in a domesticated ferret (Mustela putorius furo)

Peliod hepatocellular carcinoma was diagnosed in a domesticated ferret (Mustela putorius furo). The diagnosis was made using immunohistochemical analysis, histologic examination, and the accepted classification schemes based on histomorphologic features. Bilateral, adrenocortical hyperplasia also was evident. Speculation about a possible association between the variant of hepatocellular neoplasia diagnosed in this animal and its adrenal pathologic changes was done.

Meningoencephalomyelitis caused by Neospora caninum in a juvenile fallow deer (Dama dama)

Neosporosis, caused by the protozoan parasite Neospora caninum, is a serious cause of bovine abortion, stillbirth and perinatal death. This paper reports a clinical neosporosis in a 3-week-old fallow deer (Dama dama). The fawn was full term and appeared normal at birth. Histological lesions consisted of a multifocal necrotizing and granulomatous meningoencephalomyelitis, with intralesional protozoal cysts. Positive immunohistochemical staining and characteristic PCR products confirmed the diagnosis of N. caninum infection.

West Nile virus infection in Eastern fox squirrels (Sciurus niger)

Since the initial outbreak of West Nile virus (WNV) in the northeastern United States in 1999, the virus has rapidly spread westward and southward across the USA, causing high mortality in crows as well as sporadic mortality in horses, humans, and a wide variety of birds. In 2002 the epidemic widened as hundreds of equine and human cases and sporadic cases in other mammalian species were reported. This is the first report of WNV infection in three Eastern fox squirrels (Sciurus niger). Neurologic signs included head tilt, uncoordinated movement, paralysis, and tremors. Gross lesions were absent. Microscopic lesions consisted of lymphoplasmacytic inflammation involving the brain, heart, kidney, and liver. Formalin-fixed tissues from the three squirrels were tested for WNV antigen by immunohistochemical staining and for WNV-specific RNA by reverse transcriptase-polymerase chain reaction (RT-PCR). The kidneys of all three squirrels stained positive with immunohistochemistry for WNV, whereas the brain and heart were positive in only one animal. Two of the three squirrels were positive for WNV by RT-PCR.

The rabbit motilin receptor: molecular characterisation and pharmacology

Following identification of the human motilin receptor, we isolated the rabbit orthologue by PCR amplification and found this to be 85% identical to the open reading frame of the human receptor. The protein encoded was 84% identical to the human polypeptide. In HEK293T cells transfected with the rabbit receptor, motilin concentration-dependently increased intracellular calcium mobilisation (pEC50=9.25). After transfection with Go1alpha, motilin similarly stimulated [35S]GTPgammaS binding (pEC50=8.87). Using both systems, similar values were obtained with the human receptor, with rank-order potencies of motilin=[Nle13]-motilin>erythromycin; ghrelin was ineffective. In circular muscle preparations of rabbit gastric antrum, [Nle13]-motilin 0.1-30 nM concentration-dependently increased the amplitude of electrically-evoked, neuronally-mediated contractions (pEC50=8.3); higher concentrations increased the muscle tension (30-3000 nM). Both responses to [Nle13]-motilin faded rapidly during its continual presence. Rat or human ghrelin 0.01-10 microM were without activity. Erythromycin 30-3000 nM and 10 microM, respectively, increased neuronal activity and muscle tension in rabbit stomach. Unlike [Nle13]-motilin, the increase in neuronal activity did not fade during continual presence of submaximally-effective concentrations of erythromycin; some fade was observed at higher concentrations. We conclude that the pharmacology of the rabbit motilin receptor is similar to the human orthologue and, when expressed as a recombinant, comparable to the native receptor. However, in terms of their ability to increase neuronal activity in rabbit stomach, [Nle13]-motilin and erythromycin are distinguished by different response kinetics, reflecting different rates of ligand degradation and/or interaction with the receptor.

Relationship between knowledge and claimed compliance with genuine and false nutrition messages

Nutrition education messages about eight different foods, four of them genuine and four false, were set in a Latin square and eight questionnaires were produced and distributed to customers sitting in a cafe. For each message, subjects were asked to score the extent of their agreement and compliance. Scores were adjusted to remove effects of sex, age group and social class. Correlation coefficients between agreement and compliance scores were significant (P < 0.001) for each message. Subjects who had correct knowledge tended towards correct behaviour and those who agreed with misconceptions tended to have incorrect behaviour.

Design and analysis of food frequency questionnaires--review and novel method

A novel method is proposed for the design and analysis of a food frequency questionnaire facilitated by a computer program. The method relies on a weighed inventory undertaken by a sample of the population that is combined into a database along with the nutrient analyses of the foods consumed. The program provides an interface that enables the researcher to see the total amount of each food that was consumed, decide on what questions to ask and allocate the relevant foods to these questions. The approach means that all foods consumed can appear in the questionnaire. The nutrient analysis for each question is a weighted mean depending on the inventory. The portion weight employed for each question is derived from the weights of foods consumed in the inventory and any misperceptions in the frequency of consumption of all the subjects are corrected by calculating a factor to multiply by the frequency from the questionnaire. A viability study established the practicability of the method.

Gabapentin is not a GABAB receptor agonist

Recent experiments have demonstrated that formation of functional type B gamma-aminobutyric acid (GABA(B)) receptors requires co-expression of two receptor subunits, GABA(B1) and GABA(B2). Despite the identification of these subunits and a number of associated splice variants, there has been little convincing evidence of pharmacological diversity between GABA(B) receptors comprising different subunit combinations. However, Ng et al. [Mol. Pharmacol., 59 (2000) 144] have recently suggested a novel and important pharmacological difference between GABA(B) receptor heterodimers expressing the GABA(B1a) and GABA(B1b) receptor subunits. This study suggested that the antiepileptic GABA analogue gabapentin (Neurontin) is an agonist at GABA(B) receptors expressing the GABA(B1a) but not the GABA(B1b) receptor subunit. The importance of this finding with respect to identifying novel GABA(B) receptor subunit specific agonists prompted us to repeat these experiments in our own [35S]-GTPgammaS binding and second messenger assay systems. Here we report that gabapentin was completely inactive at recombinant GABA(B) heterodimers expressing either GABA(B1a) or GABA(B1b) receptor subunits in combination with GABA(B2) receptor subunits. In addition, in both CA1 and CA3 pyramidal neurones from rodent hippocampal slices we were unable to demonstrate any agonist-like effects of gabapentin at either pre- or post-synaptic GABA(B) receptors. In contrast, gabapentin activated a GABA(A) receptor mediated chloride conductance. Our data suggest that gabapentin is not a GABA(B)-receptor agonist let alone a GABA(B) receptor subunit selective agonist.

Grammatical style of nutrition education messages

Nutrition education messages were written about eight different foods or food products in eight different styles. Styles were suggestions, instructions using 'should', rhetorical questions using 'how about' or 'why not', statements of fact, positive commands, positive commands followed by negative commands or vice versa. Subjects (n 160) rated messages for persuasiveness and also stated how often they already complied with each message. Scores were adjusted to remove the contributions related to sex, age group, social class, reported compliance and food about which the message had been written. The main factor influencing score for persuasiveness was the extent to which subjects claimed to be already complying with the messages. There were no significant effects of the method of construction of messages on score using one-way analysis of variance.

The GABAB receptor interacts directly with the related transcription factors CREB2 and ATFx

gamma-Aminobutyric acid type B (GABA(B)) receptors mediate the metabotropic actions of the inhibitory neurotransmitter GABA. These seven-transmembrane receptors are known to signal primarily through activation of G proteins to modulate the action of ion channels or second messengers. The functional GABA(B) receptor is made up of a heterodimer consisting of two subunits, GABA(B)-R1 and GABA(B)-R2, which interact via coiled-coil domains in their C-terminal tails. By using a yeast two-hybrid approach, we have identified direct interactions between the C-terminal tails of GABA(B)-R1 and GABA(B)-R2 with two related transcription factors, CREB2 (ATF4) and ATFx. In primary neuronal cultures as well in recombinant Chinese hamster ovary cells expressing GABA(B) receptors, CREB2 is localized within the cytoplasm as well as the nucleus. Activation of the GABA(B) receptor by the specific agonist baclofen leads to a marked translocation and accumulation of CREB2 from the cytoplasm into the nucleus. We demonstrate that receptor stimulation results in activation of transcription from a CREB2 responsive reporter gene. Such a signaling mechanism is unique among Family C G protein-coupled receptors and, in the case of the GABA(B) receptor and CREB2, may play a role in long-term changes in the nervous system.

Characterization of [(3)H]-CGP54626A binding to heterodimeric GABA(B) receptors stably expressed in mammalian cells

Functional human GABA(B(1a,2)) and GABA(B(1b,2)) receptors have been stably expressed in mammalian CHO K1 cells. Detailed characterization of GABA(B) ligand binding at each of the receptors has been compared using [(3)H]-CGP54626A. In cell membranes fractions, [(3)H]-CGP54626A bound to a single site with a K(D) of 1. 51+/-1.12 nM, B(max) of 2.02+/-0.17 pmoles mg protein(-1) and 0. 86+/-0.20 nM, B(max) of 5.19+/-0.57 pmoles mg protein(-1) for GABA(B(1a,2)) and GABA(B(1b,2)) respectively. In competition binding assays the rank order was identical for both GABA(B) receptors. For known GABA(B) agonists the rank order was CGP27492>SKF97541=CGP46381>GABA>Baclofen and for GABA(B) antagonists the rank order was CGP54262A>CGP55845>CGP52432>SCH 50911>CGP51176>CGP36742=CGP35348 > or =2-OH Saclofen > or =ABPA. The allosteric effect of calcium cations was also investigated. The effect of removal of CaCl(2) from the binding assay conditions was ligand dependent to either cause a decrease in ligand affinity or to have no significant effect. However, these effects were similar for both GABA(B) receptors. A whole cell, scintillation proximity binding assay was used to determine agonist affinity at exclusively heterodimeric GABA(B) receptors. In competition assays, the rank order was the same for both GABA(B(1a,2)) and GABA(B(1b,2)) and consistent with that seen with cell membrane fractions. These data suggest that, in terms of ligand binding, the currently identified isoforms of the GABA(B) receptor are pharmacologically indistinguishable.

GABA(B) receptor heterodimer-component localisation in human brain

In recombinant cell lines, functional GABA(B) receptors are only formed by the heterodimerisation between two related G-protein coupled receptor proteins GABA(B)R1 (GBR1) and GABA(B)R2 (GBR2), whilst the individual GBR1 or GBR2 do not produce fully functional receptors. To determine whether the heterodimerisation occurs in vivo, novel polyclonal antibodies targeting the C termini of GBR1 and GBR2, were raised in different species, characterised, and used to determine the relative localisation of the reported heterodimer components in human brain tissue, using immunohistochemistry. The use of different species for the raising of the antisera allowed double immunofluorescent labelling of the receptors as an indication of GBR1/GBR2 receptor co-localisation in human brain. The presence of both proteins is reported in cerebellum, hippocampus, cortex, thalamus and basal ganglia. Regions of the brainstem including pons and medulla, also express GBR1 and GBR2 protein. The double immunofluorescence demonstrated that GBR1 and GBR2 are co-localised in the human cerebellar cortex. Together these results suggest the widespread distribution of GABA(B) receptors in human brain, and that GABA(B) receptors GBR1 and GBR2 can exist in the same cell, and therefore may function as a heterodimer in the human brain.

Relationship between knowledge of reasons underlying nutritional messages and reported compliance

Subjects (48 male and 52 female) were shown nutritional messages and asked about their frequency of compliance and how this behaviour is beneficial to health. Scores were calculated for both knowledge and behaviour. The correlation between the two scores, after adjustment for effects of social class, age and gender, was 0.57 (P < 0.001). Although most previous research has failed to relate nutritional knowledge to behaviour, this may depend on the type of knowledge and the method of questioning and this deserves further study.

Functional analysis of a human A(1) adenosine receptor/green fluorescent protein/G(i1)alpha fusion protein following stable expression in CHO cells

Fusion proteins between the human A(1) adenosine receptor and the pertussis toxin resistant (Cys351Gly) mutant of the G-protein alpha subunit G(i1)alpha (A1/Gi), and between the human A(1) adenosine receptor, the Aequorea victoria green fluorescent protein (GFP) and Cys351Gly G(i1)alpha (A1/GFP/Gi), were expressed in CHO cells. The agonist NECA caused a stimulation of [(35)S]GTPgammaS binding at both fusion proteins with similar concentration dependence as at the native receptor. However in the presence of pertussis toxin NECA stimulation of [(35)S]GTPgammaS binding was only seen at the A1/GFP/Gi fusion protein. The regulation of the adenylyl cyclase and MAP kinase effector systems by both fusion proteins was attenuated following pertussis toxin treatment. These studies demonstrate for the first time the characterisation of a fusion protein between a G-protein coupled receptor, GFP and a G-protein alpha subunit.

Calcium sensing properties of the GABA(B) receptor

The GABA(B) receptor has been shown to consist of a heterodimer of two related 7-transmembrane receptors GABAB-R1 and GABA(B)-R2. These receptors share close homology to the Ca2+-sensing receptor and also to the metabotropic glutamate receptors, which have also been shown to respond to extracellular calcium. We show here that the GABA(B) receptor also has Ca2+ sensing properties. Ca2+ (0.001-1 mM) potentiated the GABA stimulation of [35S]GTPgammaS binding in membranes prepared from CHO cells stably expressing the GABA(B)-R1/R2 heterodimer. The GABA EC50 was reduced from 72 to 7.7 microM by addition of 1 mM Ca2+, with no change in the maximum response. A similar effect was observed in membranes from rat brain cortex. Ca2+ also potentiated GABA inhibition of forskolin-stimulated cAMP levels in the CHO cells and enhanced coupling to GIRK K+ channels in Xenopus oocytes. Other divalent cations were ineffective. The effects of Ca2+ were found to be agonist dependent with baclofen having a reduced sensitivity compared to GABA. Calcium appears to act allosterically to enhance GABA responses at the GABA(B) receptor, however, unlike the Ca2+-sensing receptor and some of the mGluR family, Ca2+ does not act as a ligand in its own right.

Kinetics of ternary complex formation with fusion proteins composed of the A(1)-adenosine receptor and G protein alpha-subunits

High affinity agonist binding to G protein-coupled receptors depends on the formation of a ternary complex between agonist, receptor, and G protein. This process is too slow to be accounted for by a simple diffusion-controlled mechanism. We have tested if the interaction between activated receptor and G protein is rate-limiting by fusing the coding sequence of the human A(1)-adenosine receptor to that of Galpha(i-1) (A(1)/Galpha(i-1)) and of Galpha(o) (A(1)/Galpha(o)). Fusion proteins of the expected molecular mass were detected following transfection of HEK293 cells. Ternary complex formation was monitored by determining the kinetics for binding of the high affinity agonist (-)-N(6)-3[(125)I](iodo-4-hydroxyphenylisopropyl)adenosine; these were similar in the wild-type receptor and the fusion proteins over the temperature range of 10 to 30 degrees C. Agonist dissociation may be limited by the stability of the ternary complex. This assumption was tested by creating fusion proteins in which the Cys(351) of Galpha(i-1) was replaced with glycine (A(1)/Galpha(i-1)C351G) or isoleucine (A(1)/Galpha(i-1)C351I) to lower the affinity of the receptor for the G protein. In these mutated fusion proteins, the dissociation rate of the ternary complex was accelerated; in contrast, the rate of the forward reaction was not affected. We therefore conclude that (i) receptor activation per se rather than its interaction with the G protein is rate-limiting in ternary complex formation; (ii) the stability of the ternary complex is determined by the dissociation rate of the G protein. These features provide for a kinetic proofreading mechanism that sustains the fidelity of receptor-G protein coupling.

GABA(B) receptors function as heterodimers

Our current understanding is that functional GABA(B) receptors exist as heterodimers of two related seven-transmembrane proteins, GABA(B)-R1 and GABA(B)-R2. GABA(B)-R1 requires GABA(B)-R2 to be expressed at the cell surface as a mature glycoprotein. Cloning of the GABA(B) receptor has failed to provide molecular evidence to support the existence of true receptor subtypes. The discovery of the heterodimeric nature of the GABA(B) receptor has already changed the way we think about GPCR function and it is likely that future studies will change our understanding about how receptor subtypes can be formed.

The amino terminus of receptor activity modifying proteins is a critical determinant of glycosylation state and ligand binding of calcitonin receptor-like receptor

The calcitonin receptor-like receptor (CRLR) can function as either a receptor for calcitonin gene-related peptide (CGRP) or for adrenomedullin (ADM), depending upon the coexpression of a novel family of single transmembrane proteins, which we have called receptor activity modifying proteins or RAMPs. RAMPs 1, 2, and 3 transport CRLR to the plasma membrane with similar efficiencies, however RAMP1 presents CRLR as a terminally glycosylated, mature glycoprotein and a CGRP receptor, whereas RAMPs 2 and 3 present CRLR as an immature, core glycosylated ADM receptor. Characterization of the RAMP2/CRLR and RAMP3/CRLR receptors in HEK293T cells by radioligand binding (125I-ADM as radioligand), functional assay (cAMP measurement), or biochemical analysis (SDS-polyacrylamide gel electrophoresis) revealed them to be indistinguishable, even though RAMPs 2 and 3 share only 30% identity. Chimeric proteins were created with the transmembrane and cytosolic portions of RAMP1 associated with the amino terminus of RAMP2 (RAMP2/1) and vice versa (RAMP1/2). Coexpression of RAMP2/1 with CRLR formed a core glycosylated ADM receptor, whereas the RAMP1/2 chimera generated both core glycosylated and mature forms of CRLR and enabled both ADM and CGRP receptor binding. Hence, the glycosylation state of CRLR appears to correlate with its pharmacology.

A new strategy for controlling the level of activation in artificially stimulated muscle

Distributed stimulation of slow skeletal muscle has previously been used to produce smooth tetanic contractions at low stimulus rates. This involved distributed or interleaved stimulation of portions of the muscle with near equal tension contributions. Extending this to fast and mixed muscle encounters difficulties in getting and maintaining equal twitch responses for the portions. This need has now been circumvented by using distributed stimulation with unequal interpulse intervals. Described here is a microprocessor-based eight channel distributed muscle stimulator that can adjust stimulation timing to produce an optimally smooth tension over a range of stimulus rates even when the portions are unequal. This design is based on modeling results. Distributed stimulation experiments performed on skeletal muscle show that this method can be used to achieve smooth tension at physiological stimulus rates, which should reduce fatigue. This has important implications in functional neuromuscular stimulation (FNS) as well as in enabling experiments to be conducted to characterize the biomechanical behavior of partially activated fast and mixed muscle.

Appropriate uses for spreadsheets, databases and statistical software for the analysis of dietary data

The article presents a new approach to analysis of dietary data, emphasizing the use of database systems, but including spreadsheets and statistical programs in the process. Spreadsheets are useful in dietary research for calculations required prior to entry of the data into a dietary analysis program, for investigation of the possible effects of changing dietary components and for graphical representation of data. A dietary program can provide output of data for a large number of subjects' diets into a database. Databases should be increasingly used in data analysis due to their powerful capacity to provide immediate answers to complex research questions. The database can be used to provide output directly in a form that can be pasted into a statistical program. Some knowledge of structured query language is required to construct appropriate queries of the database; an introduction to this language with some examples is given in this article.

Comparative analysis of the efficacy of A1 adenosine receptor activation of Gi/o alpha G proteins following coexpression of receptor and G protein and expression of A1 adenosine receptor-Gi/o alpha fusion proteins

HEK293T cells were transiently transfected to express either the human A1 adenosine receptor together with pertussis toxin-resistant cysteine-to-glycine forms of the alpha subunits of Gi1 (C351G), Gi2 (C352G), and Gi3 (C351G) and wild-type Go1alpha or fusion proteins comprising the A1 adenosine receptor and these Gi/o G proteins to compare A1 adenosine receptor agonist-mediated activation of these Gi family G proteins upon coexpression of individual Gi/o G proteins and receptor versus expression as receptor-G protein fusion proteins. Addition of the adenosine receptor agonist 5'-N-ethylcarboxamidoadenosine (NECA) to membranes of pertussis toxin-treated cells resulted in a concentration-dependent stimulation of [35S]GTPgammaS binding with comparable amounts of NECA required to produce half-maximal stimulation following transfection of A1 adenosine receptor and Gi/o G proteins either as fusion proteins or as separate polypeptides. However, the magnitude of agonist-mediated activation of GTPgammaS binding was greatly enhanced by expressing the A1 adenosine receptor and Gi family G proteins from chimaeric open reading frames. This observation was consistent following the study of more than 40 agonists. No preferential activation of any G protein was observed with more than 40 A1 receptor agonists following cotransfection of receptor with G protein or transfection of receptor-G protein fusion proteins. These studies demonstrate the utility of using fusion proteins to study receptor-G protein interaction, show that the A1 adenosine receptor couples equally well to the Gi/o G proteins Gi1alpha, G i2alpha, Gi3alpha, and Go1alpha, and demonstrate that for a range of agonists there is no selectivity for activation of any particular A1 adenosine receptor-Gi/o G protein combination.

Heterodimerization is required for the formation of a functional GABA(B) receptor

GABA (gamma-aminobutyric acid) is the main inhibitory neurotransmitter in the mammalian central nervous system, where it exerts its effects through ionotropic (GABA(A/C)) receptors to produce fast synaptic inhibition and metabotropic (GABA(B)) receptors to produce slow, prolonged inhibitory signals. The gene encoding a GABA(B) receptor (GABA(B)R1) has been cloned; however, when expressed in mammalian cells this receptor is retained as an immature glycoprotein on intracellular membranes and exhibits low affinity for agonists compared with the endogenous receptor on brain membranes. Here we report the cloning of a complementary DNA encoding a new subtype of the GABAB receptor (GABA(B)R2), which we identified by mining expressed-sequence-tag databases. Yeast two-hybrid screening showed that this new GABA(B)R2-receptor subtype forms heterodimers with GABA(B)R1 through an interaction at their intracellular carboxy-terminal tails. Upon expression with GABA(B)R2 in HEK293T cells, GABA(B)R1 is terminally glycosylated and expressed at the cell surface. Co-expression of the two receptors produces a fully functional GABA(B) receptor at the cell surface; this receptor binds GABA with a high affinity equivalent to that of the endogenous brain receptor. These results indicate that, in vivo, functional brain GABA(B) receptors may be heterodimers composed of GABA(B)R1 and GABA(B)R2.