Grip Strength, Gait Speed and Plasma Markers of Neurodegeneration in Asymptomatic Middle-aged and Older Adults.

BACKGROUND: Pragmatic biomarkers of preclinical dementia would allow for easy and large-scale screening of risk in populations. Physical function measures like grip strength and gait speed are potential predictive biomarkers but their relationship with plasma markers of Alzheimer's Disease and neurodegeneration have not been elucidated. OBJECTIVES: To examine association between physical function measures and plasma markers of Alzheimer's Disease (AD) and neurodegeneration. DESIGN: Cross-sectional and longitudinal analyses. SETTING: Community-based cohort in the city of Framingham, Massachusetts. PARTICIPANTS: 2336 participants of the Framingham Heart Study Offspring cohort with an average age of 61. MEASUREMENTS: Plasma Aß40 and Aß42 were measured in 1998-2001 (Exam-7) and plasma total tau measured 5 years later (Exam-8). Grip strength, fast walk speed and chair stand speed were measured at both exams. Quantification of Aß isoforms in plasma was performed using INNO-BIA assays and plasma total-tau was measured using Quanterix Simoa HD-1 assay. Confounder-adjusted linear regression models examined associations between physical function and plasma markers, Results: Grip strength at Exam-7 was associated with plasma Aß40 (ß -0.006, p-value 0.032) at Exam-7 and plasma total-tau (ß -0.010, p-value 0.001) at Exam-8. Grip strength and fast walk speed at Exam-8 were associated with plasma total-tau at Exam-8 (GS: ß -0.009, p 0.0005; FWS: ß -0.226, p-value <0.0001). Chair stand speed was not associated with plasma markers; Aß42 was not associated with function. CONCLUSION: Grip strength and fast walk speed are associated with plasma markers of neurodegeneration in dementia-free middle aged and older individuals. Both these measures could be used as potential screening tools for identifying individuals at a higher risk for AD and related dementias alongside other validated markers.

The 'Outcome Reporting in Brief Intervention Trials: Alcohol' (ORBITAL) framework: protocol to determine a core outcome set for efficacy and effectiveness trials of alcohol screening and brief intervention.

BACKGROUND: The evidence base to assess the efficacy and effectiveness of alcohol brief interventions (ABI) is weakened by variation in the outcomes measured and by inconsistent reporting. The 'Outcome Reporting in Brief Intervention Trials: Alcohol' (ORBITAL) project aims to develop a core outcome set (COS) and reporting guidance for its use in future trials of ABI in a range of settings. METHODS/DESIGN: An international Special Interest Group was convened through INEBRIA (International Network on Brief Interventions for Alcohol and Other Drugs) to inform the development of a COS for trials of ABI. ORBITAL will incorporate a systematic review to map outcomes used in efficacy and effectiveness trials of ABI and their measurement properties, using the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) criteria. This will support a multi-round Delphi study to prioritise outcomes. Delphi panellists will be drawn from a range of settings and stakeholder groups, and the Delphi study will also be used to determine if a single COS is relevant for all settings. A consensus meeting with key stakeholder representation will determine the final COS and associated guidance for its use in trials of ABI. DISCUSSION: ORBITAL will develop a COS for alcohol screening and brief intervention trials, with outcomes stratified into domains and guidance on outcome measurement instruments. The standardisation of ABI outcomes and their measurement will support the ongoing development of ABI studies and a systematic synthesis of emerging research findings. We will track the extent to which the COS delivers on this promise through an exploration of the use of the guidance in the decade following COS publication.

A Toll-like receptor-1 variant and its characteristic cellular phenotype is associated with severe malaria in Papua New Guinean children.

Genetic factors are likely to contribute to low severe malaria case fatality rates in Melanesian populations, but association studies can be underpowered and may not provide plausible mechanistic explanations if significant associations are detected. In preparation for a genome-wide association study, 29 candidate single-nucleotide polymorphisms (SNPs) with minor allele frequencies >5% were examined in a case-control study of 504 Papua New Guinean children with severe malaria. In parallel, an immunological substudy was performed on convalescent peripheral blood mononuclear cells (PBMCs) from cases and controls. Following stimulation with a Toll-like receptor (TLR) 1/2 agonist, effector cytokines and chemokines were assayed. The only significant genetic association observed involved a nonsynonymous SNP (TLR1rs4833095) in the TLR1 gene. A recessive (TT) genotype was associated with reduced odds of severe malaria of 0.52 (95% confidence interval (0.29-0.90), P=0.006). Concentrations of pro-inflammatory cytokines interleukin-1ß and tumour necrosis factor α were significantly higher in severe malaria cases compared with healthy controls, but lower in children with the protective recessive (TT) genotype. A genetic variant in TLR1 may contribute to the low severe malaria case fatality rates in this region through a reduced pro-inflammatory cellular phenotype.

Age-related sperm DNA methylation changes are transmitted to offspring and associated with abnormal behavior and dysregulated gene expression.

Advanced paternal age (APA) has been shown to be a significant risk factor in the offspring for neurodevelopmental psychiatric disorders, such as schizophrenia and autism spectrum disorders. During aging, de novo mutations accumulate in the male germline and are frequently transmitted to the offspring with deleterious effects. In addition, DNA methylation during spermatogenesis is an active process, which is susceptible to errors that can be propagated to subsequent generations. Here we test the hypothesis that the integrity of germline DNA methylation is compromised during the aging process. A genome-wide DNA methylation screen comparing sperm from young and old mice revealed a significant loss of methylation in the older mice in regions associated with transcriptional regulation. The offspring of older fathers had reduced exploratory and startle behaviors and exhibited similar brain DNA methylation abnormalities as observed in the paternal sperm. Offspring from old fathers also had transcriptional dysregulation of developmental genes implicated in autism and schizophrenia. Our findings demonstrate that DNA methylation abnormalities arising in the sperm of old fathers are a plausible mechanism to explain some of the risks that APA poses to resulting offspring.

Metabolism of norethisterone in the greyhound.

RATIONALE: Norethisterone has been used as a successful oral contraceptive in humans for many years. It was recently permitted for use as an oestrus suppressant in racing greyhounds. To monitor the use of norethisterone as part of a routine drug surveillance programme, knowledge of its metabolism was required to enable detection. METHODS: Gas chromatography/mass spectrometry and selective derivatisation techniques have been used to identify urinary metabolites of norethisterone following oral administration to the greyhound. Metabolites were extracted using solid-phase and liquid-liquid extraction techniques. RESULTS: Several metabolites were identified, including reduced, mono-, di- and trihydroxylated steroids. The major metabolites observed were 17α-ethynyl-5ß-estrane-3α,17ß-diol, 17α-ethynyl-5α-estrane-3ß,17ß-diol, three 17α-ethynylestranetriol stereoisomers and two 17α-ethynylestranetetrol stereoisomers. The major metabolites were predominantly excreted as glucuronic acid conjugates and detection of the administration of norethisterone was possible for up to 8 days post-dose using the methods described. The nandrolone metabolites, 19-norepiandrosterone, estranediol and 19-noretiocholanolone, were also identified in the post-administration samples collected up to 8 h after dosing the treated animals. CONCLUSIONS: The urinary metabolites identified in this study have further increased the knowledge of steroid metabolism in the greyhound, providing information to support routine drug testing programmes for greyhound racing.

Investigation of L-type Ca(2+) current in the aganglionic bowel segment in Hirschsprung's disease.

BACKGROUND: Studies on animal models of Hirschsprung's disease (HD) suggest that L-type Ca(2+) channels are down-regulated in the aganglionic bowel segment, however, this has yet to be confirmed in HD patients. The objective of this study was to test the hypothesis that L-type Ca(2+) current density is decreased in smooth muscle cells (SMC) obtained from the aganglionic bowel segment of patients with HD in comparison with those from the ganglionic segment. METHODS: Smooth muscle cells were freshly isolated from colon samples obtained from HD patients undergoing pull-through surgery. L-type Ca(2+) currents were recorded using the perforated patch configuration of the whole cell voltage clamp technique and the expression levels of CACNA1C transcripts (which encode L-type Ca(2+) channels) in the ganglionic and aganglionic bowel segments were compared using real-time quantitative PCR. KEY RESULTS: All SMC displayed robust currents that had activation/inactivation kinetics typical of L-type Ca(2+) current, were inhibited by nifedipine and enhanced by the L-type Ca(2+) channel agonists FPL 64176 and Bay K 8644. Moreover, FPL 64176 activated currents were also inhibited by nifedipine. However, there was no significant difference in L-type Ca(2+) current density, CACNA1C subunit expression or sensitivity to the pharmacological agents noted above, between SMC isolated from the ganglionic and aganglionic regions of the HD colon. CONCLUSIONS & INFERENCES: In contrast to studies on genetic animal models of HD, L-type Ca(2+) currents are not down-regulated in the aganglionic bowel segment of HD patients and are therefore unlikely to account for the impaired colonic peristalsis observed in these patients.

Oxidative stress in fungal fermentation processes: the roles of alternative respiration.

Filamentous fungi are arguably the most industrially important group of microorganisms. Production processes involving these simple eukaryotes are often highly aerobic in nature, which implies these cultures are routinely subject to oxidative stress. Despite this, little is known about how filamentous fungi cope with high levels of oxidative stress as experienced in fermenter systems. More surprisingly, much of our knowledge of oxidative stress responses in fungi comes from environmental or medical studies. Here, the current understanding of oxidative stress effects and cellular responses in filamentous fungi is critically discussed. In particular the role of alternative respiration is evaluated, and the contributions of the alternative oxidase and alternative dehydrogenases in defence against oxidative stress, and their profound influence on fungal metabolism is critically examined. Finally, the importance of further research which would underpin a less empirical approach to optimising fungal strains for the fermenter environment is emphasised.

The population genetics and dynamics of the thalassemias.

The inherited disorders of hemoglobin, including the thalassemias, are by far the commonest monogenic diseases. Although several factors are responsible for their very high frequency, the major mechanism seems to be natural selection mediated by heterozygote protection against severe forms of malaria. Recent work has highlighted the complexity of the interplay among the different hemoglobin variants themselves and among different levels of malaria resistance, and is helping to explain the extraordinary heterogeneity in the distribution of the hemoglobin disorders even within short geographical distances. Some progress has also been made toward understanding the cellular and immune mechanisms that may underlie heterozygote protection against malaria in these conditions. In addition to providing valuable information about human evolutionary biology, work in this field has an increasingly important influence on the development of programs for the better management of the hemoglobin disorders, particularly in the poorer countries of the tropical world.

Survey of the fatty acid composition of retail milk differing in label claims based on production management practices.

Consumers are becoming increasingly health conscious, and food product choices have expanded. Choices in the dairy case include fluid milk labeled according to production management practices. Such labeling practices may be misunderstood and perceived by consumers to reflect differences in the quality or nutritional content of milk. Our objective was to investigate nutritional differences in specialty labeled milk, specifically to compare the fatty acid (FA) composition of conventional milk with milk labeled as recombinant bST (rbST)-free or organic. The retail milk samples (n=292) obtained from the 48 contiguous states of the United States represented the consumer supply of pasteurized, homogenized milk of 3 milk types: conventionally produced milk with no specialty labeling, milk labeled rbST-free, and milk labeled organic. We found no statistical differences in the FA composition of conventional and rbST-free milk; however, these 2 groups were statistically different from organic milk for several FA. When measuring FA as a percentage of total FA, organic milk was higher in saturated FA (65.9 vs. 62.8%) and lower in monounsaturated FA (26.8 vs. 29.7%) and polyunsaturated FA (4.3 vs. 4.8%) compared with the average of conventional and rbST-free retail milk samples. Likewise, among bioactive FA compared as a percentage of total FA, organic milk was slightly lower in trans 18:1 FA (2.8 vs. 3.1%) and higher in n-3 FA (0.82 vs. 0.50%) and conjugated linoleic acid (0.70 vs. 0.57%). From a public health perspective, the direction for some of these differences would be considered desirable and for others would be considered undesirable; however, without exception, the magnitudes of the differences in milk FA composition among milk label types were minor and of no physiological importance when considering public health or dietary recommendations. Overall, when data from our analysis of FA composition of conventional milk and milk labeled rbST-free or organic were combined with previous analytical comparisons of the quality and composition of these retail milk samples, results established that there were no meaningful differences that would affect public health and that all milks were similar in nutritional quality and wholesomeness.

Hot topic: Enhancing omega-3 fatty acids in milk fat of dairy cows by using stearidonic acid-enriched soybean oil from genetically modified soybeans.

Very long chain n-3 fatty acids such as eicosapentaenoic acid (EPA; 20:5n-3) are important in human cardiac health and the prevention of chronic diseases, but food sources are limited. Stearidonic acid (SDA; 18:4n-3) is an n-3 fatty acid that humans are able to convert to EPA. In utilizing SDA-enhanced soybean oil (SBO) derived from genetically modified soybeans, our objectives were to examine the potential to increase the n-3 fatty acid content of milk fat and to determine the efficiency of SDA uptake from the digestive tract and transfer to milk fat. Three multiparous, rumen-fistulated Holstein cows were assigned randomly in a 3 x 3 Latin square design to the following treatments: 1) control (no oil infusion); 2) abomasal infusion of SDA-enhanced SBO (SDA-abo); and 3) ruminal infusion of SDA-enhanced SBO (SDA-rum). The SDA-enhanced SBO contained 27.1% SDA, 10.4% alpha-linolenic acid, and 7.2% gamma-linolenic acid. Oil infusions provided 57 g/d of SDA with equal amounts of oil infused into either the rumen or abomasum at 6-h intervals over a 7-d infusion period. Cow numbers were limited and no treatment differences were detected for DMI or milk production (22.9+/-0.5 kg/d and 32.3+/-0.9 kg/d, respectively; least squares means +/- SE), milk protein percentage and yield (3.24+/-0.04% and 1.03+/-0.02 kg/d), or lactose percentage and yield (4.88+/-0.05% and 1.55+/-0.05 kg/d). Treatment also had no effect on milk fat yield (1.36+/-0.03 kg/d), but milk fat percentage was lower for the SDA-rum treatment (4.04+/-0.04% vs. 4.30+/-0.04% for control and 4.41+/-0.05% for SDA-abo). The SDA-abo treatment increased n-3 fatty acids to 3.9% of total milk fatty acids, a value more than 5-fold greater than that for the control. Expressed as a percentage of total milk fatty acids, values (least squares means +/- SE) for the SDA-abo treatment were 1.55+/-0.03% for alpha-linolenic acid (18:3n-3), 1.86+/-0.02 for SDA, 0.23 +/- <0.01 for eicosatetraenoic acid (20:4n-3), and 0.18+/-0.01 for EPA. Transfer efficiency of SDA to milk fat represented 39.3% (range=36.8 to 41.9%) of the abomasally infused SDA and 47.3% (range=45.0 to 49.6%) when the n-3 fatty acids downstream from SDA were included. In contrast, transfer of ruminally infused SDA to milk fat averaged only 1.7% (range=1.3 to 2.1%), indicating extensive rumen biohydrogenation. Overall, results demonstrate the potential to use SDA-enhanced SBO from genetically modified soybeans combined with proper ruminal protection to achieve impressive increases in the milk fat content of SDA and other n-3 fatty acids that are beneficial for human health.

The transmission of nosocomial pathogens in an intensive care unit: a space-time clustering and structural equation modelling approach.

We investigated the incidence of cases of nosocomial pathogens and risk factors in an intensive treatment unit ward to determine if the number of cases is dependent on location of patients and the colonization/infection history of the ward. A clustering approach method was developed to investigate the patterns of spread of cases through time for five microorganisms [methicillin-resistant Staphylococcus aureus (MRSA), Acinetobacter spp., Klebsiella spp., Candida spp., and Pseudomonas aeruginosa] using hospital microbiological monitoring data and ward records of patient-bed use. Cases of colonization/infection by MRSA, Candida and Pseudomonas were clustered in beds and through time while cases of Klebsiella and Acinetobacter were not. We used structural equation modelling to analyse interacting risk factors and the potential pathways of transmission in the ward. Prior nurse contact with colonized/infected patients, mediated by the number of patient-bed movements, were important predictors for all cases, except for those of Pseudomonas. General health and invasive surgery were significant predictors of cases of Candida and Klebsiella. We suggest that isolation and bed movement as a strategy to manage MRSA infections is likely to impact upon the incidence of cases of other opportunist pathogens.

Interaction of malaria with a common form of severe thalassemia in an Asian population.

In many Asian populations, the commonest form of severe thalassemia results from the coinheritance of HbE and beta thalassemia. The management of this disease is particularly difficult because of its extreme clinical diversity; although some genetic and adaptive factors have been identified as phenotypic modifiers, the reasons remain unclear. Because the role of the environment in the course of severe thalassemia has been neglected completely and because malaria due to both Plasmodium falciparum and Plasmodium vivax has been prevalent in Sri Lanka, we carried out a pilot study of patients with HbE beta thalassemia that showed high frequencies of antibodies to both parasite species and that 28.6% of the children had DNA-based evidence of current infection with P. vivax. Malarial antibodies then were assessed in patients with HbE beta thalassemia compared with those in age-matched controls. There was a significant increase in the frequency of antibodies in the thalassemic patients, particularly against P. vivax and in young children. There was also a higher frequency in those who had been splenectomized compared with those with intact spleens, although in the latter it was still higher than that in the controls. The thalassemic patients showed significant correlations between malaria antibody status and phenotype. Patients with HbE beta thalassemia may be more prone to malaria, particularly P. vivax, which is reflected in their clinical severity. Because P. vivax malaria is widespread in Asia, further studies of its interaction with HbE beta thalassemia and related diseases are required urgently as a part of ongoing thalassemia control programs.

Olfaction in patients with suspected parkinsonism and scans without evidence of dopaminergic deficit (SWEDDs).

BACKGROUND: Positron emission tomography and single photon emission computed tomography scanning have 87-94% sensitivity and 80-100% specificity to differentiate patients with Parkinson's disease (PD) from control subjects and patients with essential (ET) or atypical tremor. More than 10% of patients diagnosed as early PD can have scans without evidence of dopaminergic deficiency (SWEDDs). This study investigated whether smell tests can help identify possible cases with SWEDDs. METHODS: The 40 item University of Pennsylvania Smell Test (UPSIT) was used to evaluate the sense of smell in 21 SWEDDs patients. Twenty-six ET patients, 16 patients with a diagnosis of idiopathic adult onset dystonia (D), 191 non-demented PD patients and 136 control subjects were also tested. Multiple regression analyses were used to compare the mean UPSIT score in the SWEDDs group with the other four groups (ET, D, PD and controls) after adjusting for the effects of relevant covariates. RESULTS: The mean UPSIT score for the SWEDDs group was greater than in the PD group (p<0.001) and not different from the mean UPSIT in the control (p = 0.7), ET (p = 0.4) or D (p = 0.9) groups. Smell tests indicated a high probability of PD in only 23.8% of SWEDDs as opposed to 85.3% of PD patients. CONCLUSIONS: In a patient with suspected PD, a high PD probability on smell testing favours the diagnosis of PD, and a low PD probability strengthens the indication for dopamine transporter imaging.

Metabolism of methyltestosterone in the greyhound.

Gas chromatography/mass spectrometry and selective derivatisation techniques have been used to identify urinary metabolites of methyltestosterone following oral administration to the greyhound. Several metabolites were identified including reduced, mono-, di- and trihydroxylated steroids. The major metabolites observed were 17alpha-methyl-5beta-androstane-3alpha-17beta-diol, 17alpha-methyl-5beta-androstane-3alpha,16alpha,17beta-triol, and a further compound tentatively identified as 17alpha-methyl-5z-androstane-6z,17beta-triol. The most abundant of these was the 17alpha-methyl-5beta-androstane-3alpha,16alpha,17beta-triol. This metabolite was identified by comparison with a reference standard synthesised using a Grignard procedure and characterised using trimethylsilyl (TMS) and acetonide-TMS derivatisation techniques. There did not appear to be any evidence for 16beta-hydroxylation as a phase I metabolic transformation in the greyhound. However, significant quantities of 16alpha-hydroxy metabolites were detected. Selective enzymatic hydrolysis procedures indicated that the major metabolites identified were excreted as glucuronic acid conjugates. Metabolic transformations observed in the greyhound have been compared with those of other mammalian species and are discussed here.

Impact of ecosystem management on microbial community level physiological profiles of postmining forest rehabilitation.

We investigated the impacts of forest thinning, prescribed fire, and contour ripping on community level physiological profiles (CLPP) of the soil microbial population in postmining forest rehabilitation. We hypothesized that these management practices would affect CLPP via an influence on the quality and quantity of soil organic matter. The study site was an area of Jarrah (Eucalyptus marginata Donn ex Sm.) forest rehabilitation that had been mined for bauxite 12 years previously. Three replicate plots (20 x 20 m) were established in nontreated forest and in forest thinned from 3,000-8,000 stems ha(-1) to 600-800 stems ha(-1) in April (autumn) of 2003, followed either by a prescribed fire in September (spring) of 2003 or left nonburned. Soil samples were collected in August 2004 from two soil depths (0-5 cm and 5-10 cm) and from within mounds and furrows caused by postmining contour ripping. CLPP were not affected by prescribed fire, although the soil pH and organic carbon (C), total C and total nitrogen (N) contents were greater in burned compared with nonburned plots, and the coarse and fine litter mass lower. However, CLPP were affected by forest thinning, as were fine litter mass, soil C/N ratio, and soil pH, which were all higher in thinned than nonthinned plots. Furrow soil had greater coarse and fine litter mass, and inorganic phosphorous (P), organic P, organic C, total C, total N, ammonium, microbial biomass C contents, but lower soil pH and soil C/N ratio than mound soil. Soil pH, inorganic P, organic P, organic C, total C and N, ammonium, and microbial biomass C contents also decreased with depth, whereas soil C/N ratio increased. Differences in CLPP were largely (94%) associated with the relative utilization of gluconic, malic (greater in nonthinned than thinned soil and mound than furrow soil), L-tartaric, succinic, and uric acids (greater in thinned than nonthinned, mound than furrow, and 5-10 cm than 0-5 cm soil). The relative utilization of amino acids also tended to increase with increasing soil total C and organic C contents but decreased with increasing nitrate content, whereas the opposite was true for carboxylic acids. Only 45% of the variance in CLPP was explained using a multivariate multiple regression model, but soil C and N pools and litter mass were significant predictors of CLPP. Differences in soil textural components between treatments were also correlated with CLPP; likely causes of these differences are discussed. Our results suggest that 1 year after treatment, CLPP from this mined forest ecosystem are resilient to a spring prescribed fire but not forest thinning. We conclude that differences in CLPP are likely to result from complex interactions among soil properties that mediate substrate availability, microbial nutrient demand, and microbial community composition.

Does an allergy to fish pre-empt an adverse protamine reaction? A case report and a literature review.

The operating theatre exposes patients to myriad potential agents which could result in a life-threatening anaphylactic reaction. Anaesthetic drugs, blood products, and latex are only some of the possible allergens. Reactions are deemed to be anaphylactic when immediate sensitivity is combined with cardiovascular collapse. A patient who had a known allergy to shellfish presented for first time cardiopulmonary bypass. The perfusion team were concerned that there was a realistic possibility that an adverse reaction to protamine could occur. Anaphylactic reactions to protamine in patients allergic to fish have been reported. The anaesthetic team were informed and the necessary precautions taken. We report on the outcome for our patient and also discuss other risk factors and the types of reactions that can result when an adverse reaction to protamine occurs.

Differences in displayed pump flow compared to measured flow under varying conditions during simulated cardiopulmonary bypass.

Errors in blood flow delivery due to shunting have been reported to reduce flow by, potentially, up to 40-83% during cardiopulmonary bypass. The standard roller-pump measures revolutions per minute and a calibration factor for different tubing sizes calculates and displays flow accordingly. We compared displayed roller-pump flow with ultrasonically measured flow to ascertain if measured flow correlated with the heart-lung pump flow reading. Comparison of flows was measured under varying conditions of pump run duration, temperature, viscosity, varying arterial/venous loops, occlusiveness, outlet pressure, use of silicone or polyvinyl chloride (PVC) in the roller race, different tubing diameters, and use of a venous vacuum-drainage device.