The Relationship Between Nocturnal Blood Pressure and Hemorrhagic Stroke in Chinese Hypertensive Patients

To study the relationship between nocturnal blood pressure (BP) variation and spontaneous intracerebral hemorrhage (ICH) among Chinese hypertensive patients and its clinical significance, the authors retrospectively screened 371 patients with primary hypertension (189 patients with ICH, 182 patients without ICH) in Shanghai and analyzed their demographics, clinical information, nocturnal blood pressure variability and medication. Compared with the control group, the levels of blood glucose, triglycerides, and creatinine were significantly increased in the ICH group, along with a marked reduction in nocturnal BP drop (P<.05). Multivariate logistic regression indicated that blood glucose, creatinine, and nocturnal mean arterial pressure were risk factors for ICH, and the magnitude of nocturnal BP drop was negatively related to the risk for ICH. There was no significant difference in the prevalence of reverse dippers between the large hematoma volume group and the small hematoma volume group (χ²=2.529, P=.112), nor among the patients taking angiotensin‐converting enzyme inhibitors, angiotensin receptor blockers, or calcium channel blockers (χ²=1.981, P=.371). Reverse dipping is associated with the risk for ICH, suggesting that appropriate antihypertensive drug and chronotherapy might be effective to normalize the rhythm of abnormal circadian variation in hypertensive patients.     

Molecular epidemiology of group B streptococci in Ireland reveals a diverse population with evidence of capsular switching

The molecular epidemiology of group B Streptococcus (GBS) in Ireland was investigated. Invasive (n?=?132) and non-invasive (n?=?45) isolates, collected in 2007–2011, were analysed by multilocus locus sequence typing, capsular polysaccharide (CPS) serotyping, profiling of surface proteins, pilus islands (PI), and antimicrobial susceptibility. Isolates grouped into 45 sequence types and five main clonal complexes (CC). CC1, CC17 and CC23 represented 67.2 % of isolates and the most prevalent serotypes Ia, III and V. Serotype and surface protein genes were largely predictive of CC. Accordingly, CPS V/alp3, CPS Ib/CPS II/bca?+?bac, and CPS Ia/eps predominated in CC1, CC12 and CC23, respectively, and CPS III/rib in CC17 and CC19. Supporting their vaccine potential, all isolates harboured at least one PI, of which the PI-1?+?PI-2a combination was most prevalent. Macrolide resistance was found in 18.6 % of isolates. erm(B) and the globally disseminated CC1/CPS V were the most common resistance mechanism and CC/CPS type, respectively. CC17, significantly associated with neonatal disease, was also prevalent in pregnant adults, but was underrepresented among non-pregnant adults. Two of 46 CC17 isolates (typically CPS III) were CPS IV. Sequence analysis confirmed capsular switching and their relatedness to CC17/CPS IV strains recently characterized in France. CPS IV, detected only in invasive isolates (6.8 %), was most prevalent in adults (12 %) and showed an increase in prevalence to that reported (1.4 %) for invasive isolates in Ireland 1997–1999. Increases in serotype IV and evidence of capsular switching in CC17 highlights the importance of ongoing surveillance of GBS and may have implications for vaccine development strategies.     

Perennial grasslands enhance biodiversity and multiple ecosystem services in bioenergy landscapes

Agriculture is being challenged to provide food, and increasingly fuel, for an expanding global population. Producing bioenergy crops on marginal lands—farmland suboptimal for food crops—could help meet energy goals while minimizing competition with food production. However, the ecological costs and benefits of growing bioenergy feedstocks—primarily annual grain crops—on marginal lands have been questioned. Here we show that perennial bioenergy crops provide an alternative to annual grains that increases biodiversity of multiple taxa and sustain a variety of ecosystem functions, promoting the creation of multifunctional agricultural landscapes. We found that switchgrass and prairie plantings harbored significantly greater plant, methanotrophic bacteria, arthropod, and bird diversity than maize. Although biomass production was greater in maize, all other ecosystem services, including methane consumption, pest suppression, pollination, and conservation of grassland birds, were higher in perennial grasslands. Moreover, we found that the linkage between biodiversity and ecosystem services is dependent not only on the choice of bioenergy crop but also on its location relative to other habitats, with local landscape context as important as crop choice in determining provision of some services. Our study suggests that bioenergy policy that supports coordinated land use can diversify agricultural landscapes and sustain multiple critical ecosystem services.In agricultural landscapes, balancing the provisioning of food and energy with maintenance of biodiversity and ecosystem functions is a global challenge. To avoid impacts on food production, attention is increasingly being focused on the potential for marginal lands to support bioenergy production (1). Marginal lands, those suboptimal for food production, may consist of relatively small areas within generally productive landscapes or larger regions where conditions generally limit crop productivity. However, there is increasing recognition that these lands are already performing a variety of useful functions, and their conversion to bioenergy cropping could reduce these services. For example, in the north central United States, rising commodity prices are predicted to bring marginal croplands—including Conservation Reserve Program lands—into annual crop production with negative impacts on wildlife habitat and water quality (2, 3). With 2013 corn plantings at recent record highs (4) and new reports of grassland and wetland conversion to cropland (5, 6), this may be occurring already.An alternative to annual cropping is conversion of marginal croplands to perennial, cellulosic crops for bioenergy. Although current US biofuel production centers on grain ethanol derived from annual monocultures of maize (Zea mays), this situation could change with full implementation of the 2007 US Energy Independence and Security Act (7), which calls for increased production of cellulosic biofuels. In the Midwest United States, perennial grasses and forbs grown on marginal lands could provide up to 25% of national targets for cellulosic biofuel, with substantial greenhouse gas (GHG) benefits (8). Moreover, increasing the area of perennial cover on the landscape is predicted to positively affect a diverse array of organisms and ecological functions (9–11), leading to important synergies that have not yet informed the ongoing bioenergy debate. Here we provide the most comprehensive empirical evaluation of this hypothesis to date, reporting data that elucidate the impacts of different bioenergy cropping systems on a wide variety of organisms and the ecosystem functions they perform.Previous studies have examined the ability of select bioenergy crops to support specific taxa (12) or individual services such as energy production (13) or GHG mitigation (14), without consideration of the tradeoffs or synergies that can arise when considering entire suites of organisms and ecosystem functions. We report on a unique multidisciplinary study of matched sets of organisms and ecosystem services and show that perennial grass energy crops (switchgrass, Panicum virgatum, and mixed prairie plantings) synergistically enhance diversity of a variety of organisms and levels of the services they provide. We further quantify the importance of landscape context on service provisioning, suggesting that policy supporting intentional design of bioenergy landscapes could increase sustainability of both food and energy production.     

Inactivation of a single gene enables microaerobic growth of the obligate anaerobe Bacteroides fragilis

Bacteroides fragilis can replicate in atmospheres containing ≤0.05% oxygen, but higher concentrations arrest growth by an unknown mechanism. Here we show that inactivation of a single gene, oxe (i.e., oxygen enabled) in B. fragilis allows for growth in concentrations as high as 2% oxygen while increasing the tolerance of this organism to room air. Known components of the oxidative stress response including the ahpC, kat, batA-E, and tpx genes were not individually important for microaerobic growth. However, a Δoxe strain scavenged H(2)O(2) at a faster rate than WT, indicating that reactive oxygen species may play a critical role in limiting growth of this organism to low-oxygen environments. Clinical isolates of B. fragilis displayed a greater capacity for growth under microaerobic conditions than fecal isolates, with some encoding polymorphisms in oxe. Additionally, isolation of oxygen-enabled mutants of Bacteroides thetaiotaomicron suggests that Oxe may mediate growth arrest of other anaerobes in oxygenated environments.     

Repeat percutaneous coronary revascularization: Indications and outcomes in a “Real World” cohort

Objectives : To investigate rates of and reasons for second and subsequent stent procedures in an unselected, “real‐world” population. Background : Repeat stenting is the primary difference reported in clinical trials of alternative revascularization strategies. The incidence, indication, and outcome for repeat stenting in contemporary practice outside the more selective populations of trials and registries has not been described. Method : All patients undergoing a first percutaneous coronary intervention (PCI) procedure with stenting from January 2001 to August 2009 (10,509) from a large UK tertiary referral and district general hospital were identified. Mortality and the incidence, timing, and indication for repeat revascularization in this population were investigated from patient records. Results : Of 10,509 patients undergoing a first PCI and stent implant 23.5% underwent repeat angiography of which 11.2% required repeat PCI and 2% coronary artery bypass grafting (median follow‐up of 3.8 years). A total of 1.3% went on to a third PCI. The commonest indication for repeat stenting was disease progression remote from the original stent (46%) and planned staged PCI (23%); 21% had a stent‐related indication. Functional assessment before repeat stenting was used in one‐third of stable patients. Mortality was 2.5% per annum. Conclusions : In contemporary practice, patients undergoing a first stenting procedure have a low subsequent mortality, and the substantial majority (86.4%) requires no further revascularization over a median 3.8 year follow‐up. For those who do require repeat stenting, this is most commonly at a site remote from the first stent. © 2012 Wiley Periodicals, Inc.     

Surgical Treatment of Trochanteric and Cervical Hip Fractures in the United States: 2000–2009

The objective of this study was to evaluate the most common treatments performed for hip fractures over the last decade in the United States. The leading treatment for trochanteric fractures was internal fixation, accounting for 96%–98% of surgical treatments each year. For cervical fractures, hemiarthroplasty (HA), total hip arthroplasty (THA), and internal fixation were performed nearly 61%, 5%, and 33% of the time, respectively, each year without any sign of change during the period assessed. The surgical choice for cervical fractures varied greatly by patient age. In 2009, two-thirds of patients younger than 60 years underwent internal fixation while two-thirds of patients 60 years or older underwent HA. Regardless of patient age, HA was performed more often than THA for cervical hip fractures.