Batrachomyia strigapes (Diptera) parasitism of Uperoleia laevigata (Anura).

To quantify the occurrence of the dipteran parasite Batrachomyia strigapes, the ground frog assemblage associated with a large ephemeral wetland in Western Sydney was sampled between January 1999 and April 2000. Parasite infection was restricted to Uperoleia laevigata (5.1%, n = 1,492). Parasites were found under the parotoid glands, most frequently on the left side. After correction for frog size, infection was shown to significantly reduce frog weight. Despite reduced individual fitness, because the level of infection was low in the population, it is unlikely to have a major effect on the anuran population under current environmental conditions.     

Muscle Carnosine Is Associated with Cardiometabolic Risk Factors in Humans

BackgroundCarnosine is a naturally present dipeptide abundant in skeletal muscle and an over-the counter food additive. Animal data suggest a role of carnosine supplementation in the prevention and treatment of obesity, insulin resistance, type 2 diabetes and cardiovascular disease but only limited human data exists.ConclusionOur data shows that higher carnosine content in human skeletal muscle is positively associated with insulin resistance and fasting metabolic preference for glucose. Moreover, it is negatively associated with HDL-cholesterol and basal energy expenditure. Intervention studies targeting insulin resistance, metabolic and cardiovascular disease risk factors are necessary to evaluate its putative role in the prevention and management of type 2 diabetes and cardiovascular disease.     

Vital Signs Directed Therapy: Improving Care in an Intensive Care Unit in a Low-Income Country

Background

Global Critical Care is attracting increasing attention. At several million deaths per year, the worldwide burden of critical illness is greater than generally appreciated. Low income countries (LICs) have a disproportionally greater share of critical illness, and yet critical care facilities are scarce in such settings. Routines utilizing abnormal vital signs to identify critical illness and trigger medical interventions have become common in high-income countries but have not been investigated in LICs. The aim of the study was to assess whether the introduction of a vital signs directed therapy protocol improved acute care and reduced mortality in an Intensive Care Unit (ICU) in Tanzania.

Methods and Findings

Prospective, before-and-after interventional study in the ICU of a university hospital in Tanzania. A context-appropriate protocol that defined danger levels of severely abnormal vital signs and stipulated acute treatment responses was implemented in a four week period using sensitisation, training, job aids, supervision and feedback. Acute treatment of danger signs at admission and during care in the ICU and in-hospital mortality were compared pre and post-implementation using regression models. Danger signs from 447 patients were included: 269 pre-implementation and 178 post-implementation. Acute treatment of danger signs was higher post-implementation (at admission: 72.9% vs 23.1%, p<0.001; in ICU: 16.6% vs 2.9%, p<0.001). A danger sign was five times more likely to be treated post-implementation (Prevalence Ratio (PR) 4.9 (2.9–8.3)). Intravenous fluids were given in response to 35.0% of hypotensive episodes post-implementation, as compared to 4.1% pre-implementation (PR 6.4 (2.5–16.2)). In patients admitted with hypotension, mortality was lower post-implementation (69.2% vs 92.3% p = 0.02) giving a numbers-needed-to-treat of 4.3. Overall in-hospital mortality rates were unchanged (49.4% vs 49.8%, p = 0.94).

Conclusion

The introduction of a vital signs directed therapy protocol improved the acute treatment of abnormal vital signs in an ICU in a low-income country. Mortality rates were reduced for patients with hypotension at admission but not for all patients.     

Hyperaccumulation of cadmium in Matricaria chamomilla: a never-ending story?

Chamomile (Matricaria chamomilla L.) is a widely used medicinal plant but may also accumulate metals including cadmium. Because recent paper (Masarovi?ová et al. 2010 Acta Physiol Plant 32:823–829) contradicts previous results of our research group and suggested Cd “hyper/accumulation” in chamomile, present study examined Cd uptake in a long-term experiment (7 weeks) using low Cd concentration (1.5 μM). Besides, typical Cd hyperaccumulator Thlaspi caerulescens and Ni hyperaccumulator Thlaspi goesingense were also cultured under identical conditions. Data obtained indicate that shoot Cd content and bioaccumulation factor (BAF) in chamomile was ca. 5–10 times lower than that in Thlaspi. In this view, chamomile is not a hyperaccumulator species. Comparison of shoot Cd content, BAF and translocation factor (TF) in selected crops is also provided.     

Cases with manifestation of <Emphasis Type="Italic">chemodectoma</Emphasis> diagnosed in dogs in Department of Internal Diseases with Horses,Dogs and Cats Clinic,Veterinary Medicine Faculty,University of Environmental and Life Sciences,Wroclaw, Poland

In the period of 3 years, 9 tumours of chemodectoma were supravitally diagnosed and histopathologically verified in dogs. In this period 15 351 dogs were admitted to the Clinic of Dogs and Cats and 2 145 dogs were examined in the cardiological outpatient clinic for dogs. This tumour is located in a typical place - at the base of the heart. Most frequently the tumour manifested in older boxers. Only in one case such a tumour was diagnosed in another breed of dogs. The tumours ranged in size between 3 and 16 cm in diameter. The principal sign accompanying tumours of cardiac base involved dyspnoea but in 3 cases the tumours yielded no clinical signs. All the diagnoses were additionally verified using immunohistochemical examination. We used antibodies to chromogranin A (clone DAK-A3 1:100), synaptophysin (clone SY38 1:20) and neuron-specific enolase (clone BBS/NC/VI-H14 1:150). An immunohistochemical examination is vital for the diagnosis since it allows to differentiate histologically distinct types of neoplasia which may locate in the same site and may manifest a similar histological pattern.     

Evaluation of TatABC overproduction on Tat- and Sec-dependent protein secretion in Streptomyces lividans

The majority of bacterial proteins are exported across the cytoplasmic membrane via the Sec pathway, but also the more recently discovered twin-arginine translocation (Tat) route seems to play an important role for protein secretion in Streptomyces lividans in whose genome tatA, tatB and tatC have been identified. In the present work we showed that simultaneous overproduction of TatABC improved the Tat-dependent secretion capacity as could be concluded from the increased amount of secreted xylanase C, an exclusive Tat-dependent substrate. This result demonstrates that next to the availability of energy to drive secretion, also the number of translocases can be rate-limiting for Tat-dependent secretion. On the other hand, tatABC overexpression was found to diminish secretion of the Sec-dependent proteins xylanase B and subtilisin inhibitor in S. lividans. These results reveal cross-talk between both pathways in S. lividans.     

Cofactor assisted gating mechanism in the active site of NADH oxidase from Thermus thermophilus

NADH oxidase (NOX) from Thermus thermophilus is a member of a structurally homologous flavoprotein family of nitroreductases and flavin reductases. The importance of local conformational dynamics in the active site of NOX has been recently demonstrated. The enzyme activity was increased by 250% in the presence of 1 M urea with no apparent perturbation of the native structure of the protein. The present in silico results correlate with the in vitro data and suggest the possible explanation about the effect of urea on NOX activity at the molecular level. Both, X-ray structure and molecular dynamics (MD) simulations, show open conformation of the active site represented by approximately 0.9 nm distance between the indole ring of Trp47 and the isoalloxazine ring of FMN412. In this conformation, the substrate molecule can bind in the active site without sterical restraints. MD simulations also indicate more stable conformation of the active site called "closed" conformation. In this conformation, Trp47 and the isoalloxazine ring of FMN412 are so close to each other (approximately 0.5 nm) that the substrate molecule is unable to bind between them without perturbing this conformation. The open/close transition of the active site between Trp47 and the flavin ring is accompanied by release of the "tightly" bound water molecule from the active site--cofactor assisted gating mechanism. The presence of urea in aqueous solutions of NOX prohibits closing of the active site and even unlocks the closed active site because of the concomitant binding of a urea molecule in the active site cavity. The binding of urea in the active site is stabilized by formation of one/two persistent hydrogen bonds involving the carbonyl group of the urea molecule. Our report represents the first MD study of an enzyme from the novel flavoprotein family of nitroreductases and flavin reductases. The common occurrence of aromatic residues covering the active sites in homologous enzymes suggests the possibility of a general gating mechanism and the importance of local dynamics within this flavoprotein family.     

Preparation, crystallization and preliminary X-ray analysis of the Fab fragment of monoclonal antibody MN423, revealing the structural aspects of Alzheimer's paired helical filaments

Monoclonal antibody (mAb) MN423 recognizes Alzheimer's disease specific conformation of tau protein assembled into paired helical filaments (PHF). Since the three-dimensional structure of PHF is currently unavailable, the structure of MN423 binding site could provide important information about PHF conformation with the consequences for the Alzheimer's disease prevention and cure. Fab fragment of MN423 was prepared and purified. We have identified two different conditions for crystallization of the Fab fragment that yielded two crystal forms. They diffracted to 3.0 and 1.6 A resolution with four and one molecule in the asymmetric unit, respectively. Both crystal forms belonged to the space group P2(1) with unit cell parameters a = 76.4 A, b = 138.4 A, c = 92.4 A, beta = 101.9 degrees , and a = 71.5 A, b = 36.8 A, c = 85.5 A, beta = 113.9 degrees .