Spatial scales of interactions among bacteria and between bacteria and the leaf surface.

Microbial life on plant leaves is characterized by a multitude of interactions between leaf colonizers and their environment. While the existence of many of these interactions has been confirmed, their spatial scale or reach often remained unknown. In this study, we applied spatial point pattern analysis to 244 distribution patterns of Pantoea agglomerans and Pseudomonas syringae on bean leaves. The results showed that bacterial colonizers of leaves interact with their environment at different spatial scales. Interactions among bacteria were often confined to small spatial scales up to 5-20 μm, compared to interactions between bacteria and leaf surface structures such as trichomes which could be observed in excess of 100 μm. Spatial point-pattern analyses prove a comprehensive tool to determine the different spatial scales of bacterial interactions on plant leaves and will help microbiologists to better understand the interplay between these interactions

What you need to know about: delirium in older adults in hospital

Delirium is a clinical syndrome characterised by a disturbance of perception, consciousness and/or cognitive function, with an acute onset, fluctuating course and a severe deterioration arising over hours or days. Delirium is usually triggered by a combination of influences including acute illness, surgery, drugs and environmental factors. It is commonly seen in older people presenting to hospital, but can also develop during hospitalisation. There are three types of delirium: hypoactive, hyperactive and mixed. All patients over 65 years old presenting to hospital should be screened for delirium using the ‘4AT’ tool. An alternate method for diagnosing hospital-acquired delirium is described. This article outlines a 10-stage method for diagnosing, managing and preventing delirium, with emphasis on which areas of the history and examination should be prioritised, what the salient investigations are and both non-pharmacological and pharmacological approaches to preventing and treating delirium. Finally, this article explores which patients require specialist referrals or investigations and how to best follow up patients with delirium

Early diagnosis and treatment of HIV infection: magnitude of benefit on short-term mortality is greatest in older adults.

BACKGROUND: the number and proportion of adults diagnosed with HIV infection aged 50 years and older has risen. This study compares the effect of CD4 counts and anti-retroviral therapy (ART) on mortality rates among adults diagnosed aged ≥50 with those diagnosed at a younger age. METHODS: retrospective cohort analysis of national surveillance reports of HIV-diagnosed adults (15 years and older) in England, Wales and Northern Ireland. The relative impacts of age, CD4 count at diagnosis and ART on mortality were determined in Cox proportional hazards models. RESULTS: among 63,805 adults diagnosed with HIV between 2000 and 2009, 9% (5,683) were aged ≥50 years; older persons were more likely to be white, heterosexual and present with a CD4 count <200 cells/mm(3) (48 versus 32% P < 0.01) and AIDS at diagnosis (19 versus 9%, P < 0.01). One-year mortality was higher in older adults (10 versus 3%, P < 0.01) and especially in those diagnosed with a CD4 <200 cells/mm(3) left untreated (46 versus 15%, P < 0.01). While the relative mortality risk reduction from ART initiation at CD <200 cells/mm(3) was similar in both age groups, the absolute risk difference was higher among older adults (40 versus 12% fewer deaths) such that the number needed to treat older adults to prevent one death was two compared with eight among younger adults. CONCLUSIONS: the magnitude of benefit from ART is greater in older adults than younger adults. Older persons should be considered as a target for HIV testing. Coupled with prompt treatment, earlier diagnosis is likely to reduce substantially deaths in this group

Montreal Cognitive Assessment for the diagnosis of Alzheimer's disease and other dementias.

BACKGROUND: Dementia is a progressive syndrome of global cognitive impairment with significant health and social care costs. Global prevalence is projected to increase, particularly in resource-limited settings. Recent policy changes in Western countries to increase detection mandates a careful examination of the diagnostic accuracy of neuropsychological tests for dementia. OBJECTIVES: To determine the diagnostic accuracy of the Montreal Cognitive Assessment (MoCA) at various thresholds for dementia and its subtypes. SEARCH METHODS: We searched MEDLINE, EMBASE, BIOSIS Previews, Science Citation Index, PsycINFO and LILACS databases to August 2012. In addition, we searched specialised sources containing diagnostic studies and reviews, including MEDION (Meta-analyses van Diagnostisch Onderzoek), DARE (Database of Abstracts of Reviews of Effects), HTA (Health Technology Assessment Database), ARIF (Aggressive Research Intelligence Facility) and C-EBLM (International Federation of Clinical Chemistry and Laboratory Medicine Committee for Evidence-based Laboratory Medicine) databases. We also searched ALOIS (Cochrane Dementia and Cognitive Improvement Group specialized register of diagnostic and intervention studies). We identified further relevant studies from the PubMed 'related articles' feature and by tracking key studies in Science Citation Index and Scopus. We also searched for relevant grey literature from the Web of Science Core Collection, including Science Citation Index and Conference Proceedings Citation Index (Thomson Reuters Web of Science), PhD theses and contacted researchers with potential relevant data. SELECTION CRITERIA: Cross-sectional designs where all participants were recruited from the same sample were sought; case-control studies were excluded due to high chance of bias. We searched for studies from memory clinics, hospital clinics, primary care and community populations. We excluded studies of early onset dementia, dementia from a secondary cause, or studies where participants were selected on the basis of a specific disease type such as Parkinson's disease or specific settings such as nursing homes. DATA COLLECTION AND ANALYSIS: We extracted dementia study prevalence and dichotomised test positive/test negative results with thresholds used to diagnose dementia. This allowed calculation of sensitivity and specificity if not already reported in the study. Study authors were contacted where there was insufficient information to complete the 2x2 tables. We performed quality assessment according to the QUADAS-2 criteria.Methodological variation in selected studies precluded quantitative meta-analysis, therefore results from individual studies were presented with a narrative synthesis. MAIN RESULTS: Seven studies were selected: three in memory clinics, two in hospital clinics, none in primary care and two in population-derived samples. There were 9422 participants in total, but most of studies recruited only small samples, with only one having more than 350 participants. The prevalence of dementia was 22% to 54% in the clinic-based studies, and 5% to 10% in population samples. In the four studies that used the recommended threshold score of 26 or over indicating normal cognition, the MoCA had high sensitivity of 0.94 or more but low specificity of 0.60 or less. AUTHORS' CONCLUSIONS: The overall quality and quantity of information is insufficient to make recommendations on the clinical utility of MoCA for detecting dementia in different settings. Further studies that do not recruit participants based on diagnoses already present (case-control design) but apply diagnostic tests and reference standards prospectively are required. Methodological clarity could be improved in subsequent DTA studies of MoCA by reporting findings using recommended guidelines (e.g. STARDdem). Thresholds lower than 26 are likely to be more useful for optimal diagnostic accuracy of MoCA in dementia, but this requires confirmation in further studies.This is the final version of the article. It first appeared from Wiley via http://dx.doi.org/10.1002/14651858.CD010775.pub

A quantitative cross-sectional survey of psychosocial stimulation and counselling interventions at nutritional rehabilitation units in Southern Malawi

Background Inpatient treatment at nutritional rehabilitation units (NRUs) is needed for children who have severe acute malnutrition (SAM) and acute illness, loss of appetite, or severe oedema. World Health Organization guidelines state that nutritional counselling should be done with primary caregivers at NRUs. These recommendations also include psychosocial stimulation interventions to improve developmental outcomes in children with SAM. However, there is limited information about the delivery of these types of interventions for caregivers and children in NRU settings. The primary objective of this research was therefore to obtain data about NRU resources, activities, and protocols relevant to psychosocial stimulation and counselling interventions during inpatient treatment of children with SAM. Methods A cross-sectional survey was administered by interview at all 16 NRUs in seven districts in Southern Malawi. Participants were health workers, nurses, and nutritionists employed at the respective NRUs. Results The response rate was 100% across NRUs. Half of participants said that psychosocial stimulation interventions are conducted at their respective NRUs, yet none of the NRUs have protocols for delivery of these interventions. Furthermore, 7/16 (44%) NRUs have no resources for psychosocial stimulation including play materials. Thirteen of 16 (81%) participants said that they feel this type of intervention is very important and 3/16 (19%) participants said that this somewhat important for children with SAM. All NRUs provide counselling to caregivers about breastfeeding and nutrition; 15/16 (94%) also give counselling about water, sanitation and hygiene. Conclusions Ultimately, results from this survey highlighted that there is a need to invest in comprehensive interventions to improve developmental and nutritional outcomes in these vulnerable children requiring admission to NRUs

Increased expression of axogenesis-related genes and mossy fibre length in dentate granule cells from adult HuD overexpressor mice

The neuronal RNA-binding protein HuD plays a critical role in the post-transcriptional regulation of short-lived mRNAs during the initial establishment and remodelling of neural connections. We have generated transgenic mice overexpressing this protein (HuD-Tg) in adult DGCs (dentate granule cells) and shown that their mossy fibres contain high levels of GAP-43 (growth-associated protein 43) and exhibit distinct morphological and electrophysiological properties. To investigate the basis for these changes and identify other molecular targets of HuD, DGCs from HuD-Tg and control mice were collected by LCM (laser capture microscopy) and RNAs analysed using DNA microarrays. Results show that 216 known mRNAs transcripts and 63 ESTs (expressed sequence tags) are significantly up-regulated in DGCs from these transgenic mice. Analyses of the 3′-UTRs (3′-untranslated regions) of these transcripts revealed an increased number of HuD-binding sites and the presence of several known instability-conferring sequences. Among these, the mRNA for TTR (transthyretin) shows the highest level of up-regulation, as confirmed by qRT–PCR (quantitative reverse transcription–PCR) and ISH (in situ hybridization). GO (gene ontology) analyses of up-regulated transcripts revealed a large over-representation of genes associated with neural development and axogenesis. In correlation with these gene expression changes, we found an increased length of the infrapyramidal mossy fibre bundle in HuD-Tg mice. These results support the notion that HuD stabilizes a number of developmentally regulated mRNAs in DGCs, resulting in increased axonal elongation

Features of the popliteal lymph nodes seen on musculoskeletal MRI in a Western population

To asses the features and explore the clinical relevance of popliteal lymph nodes (PLNs) detected on MRI examination for different pathologies of the knee. A total of 150 knee MRIs, which were conducted for various indications, were retrospectively collected from the Picture Archiving and Communication System. Imaging planes in at least two orthogonal planes were mandatory, with a field of view extending 15 cm cranial from the joint space. The localization of the PLN was determined by measuring the distance of the lowest border of the PLN to the lowest border of the lateral femoral condyle. Clinical diagnosis was obtained from radiology reports and a statistician performed the statistical analysis. The patients were 70 males [mean age 36.6 years (range: 5-72 years)] and 80 females [mean age 41.1 years (range: 9-76 years)]. In 36.7% of the patients, a PLN was visible. The number of PLNs was negatively associated with age (p < 0.001). The mean number of PLNs was 0.5 PLN per patient. The mean length, height, and width were respectively: 0.57 cm (SD = 0.15), 0.84 cm (SD = 0.26), and 0.71 cm (SD = 0.23). The mean location was 5.8 cm (SD = 1.61). No association was found between the presence of PLNs and internal derangement, inflammation, or cancer (p = 0.368). PLNs appearance is age related, with a higher frequency at a young age. The presence of the PLNs showed no relation to a specific clinical situatio

Recurrent delirium over 12 months predicts dementia: results of the Delirium and Cognitive Impact in Dementia (DECIDE) study.

BACKGROUND: Delirium is common, distressing and associated with poor outcomes. Previous studies investigating the impact of delirium on cognitive outcomes have been limited by incomplete ascertainment of baseline cognition or lack of prospective delirium assessments. This study quantified the association between delirium and cognitive function over time by prospectively ascertaining delirium in a cohort aged ≥ 65 years in whom baseline cognition had previously been established. METHODS: For 12 months, we assessed participants from the Cognitive Function and Ageing Study II-Newcastle for delirium daily during hospital admissions. At 1-year, we assessed cognitive decline and dementia in those with and without delirium. We evaluated the effect of delirium (including its duration and number of episodes) on cognitive function over time, independently of baseline cognition and illness severity. RESULTS: Eighty two of 205 participants recruited developed delirium in hospital (40%). One-year outcome data were available for 173 participants: 18 had a new dementia diagnosis, 38 had died. Delirium was associated with cognitive decline (-1.8 Mini-Mental State Examination points [95% CI -3.5 to -0.2]) and an increased risk of new dementia diagnosis at follow up (OR 8.8 [95% CI 1.9-41.4]). More than one episode and more days with delirium (>5 days) were associated with worse cognitive outcomes. CONCLUSIONS: Delirium increases risk of future cognitive decline and dementia, independent of illness severity and baseline cognition, with more episodes associated with worse cognitive outcomes. Given that delirium has been shown to be preventable in some cases, we propose that delirium is a potentially modifiable risk factor for dementia

Vitamin D₃supplementation and childhood diarrhea: a randomized controlled trial.

OBJECTIVE: To investigate the effect of vitamin D3 supplementation on the incidence and risk for first and recurrent diarrheal illnesses among children in Kabul, Afghanistan. METHODS: This double-blind placebo-controlled trial randomized 3046 high-risk 1- to 11-month-old infants to receive 6 quarterly doses of oral vitamin D3 (cholecalciferol 100000 IU) or placebo in inner city Kabul. Data on diarrheal episodes (≥ 3 loose/liquid stools in 24 hours) was gathered through active and passive surveillance over 18 months of follow-up. Time to first diarrheal illness was analyzed by using Kaplan-Meier plots. Incidence rates and hazard ratios (HRs) were calculated by using recurrent event Poisson regression models. RESULTS: No significant difference existed in survival time to first diarrheal illness (log rank P = .55). The incidences of diarrheal episodes were 3.43 (95% confidence interval [CI], 3.28-3.59) and 3.59 per child-year (95% CI, 3.44-3.76) in the placebo and intervention arms, respectively. Vitamin D3 supplementation was found to have no effect on the risk for recurrent diarrheal disease in either intention-to-treat (HR, 1.05; 95% CI, 0.98-1.17; P = .15) or per protocol (HR, 1.05; 95% CI, 0.98-1.12; P = .14) analyses. The lack of preventive benefit remained when the randomized population was stratified by age groups, nutritional status, and seasons. CONCLUSIONS: Quarterly supplementation with vitamin D3 conferred no reduction on time to first illness or on the risk for recurrent diarrheal disease in this study. Similar supplementation to comparable populations is not recommended. Additional research in alternative settings may be helpful in elucidating the role of vitamin D3 supplementation for prevention of diarrheal diseases