Control of water intake by a pathway from the nucleus of the solitary tract to the paraventricular hypothalamic nucleus.

Several brain areas have been shown to participate in thirst and control of fluid intake. An understanding of how these circuits interact, and their roles in the activation, maintenance, and termination of fluid intake remains incomplete. Central glucagon-like peptide-1 (GLP-1) receptor activation appears to be an important part of the termination of drinking, but the site(s) of action for this suppression has not yet been determined. In an attempt to use GLP-1 responsiveness as a means to screen targets of hindbrain cells that participate in the termination of thirst and the resultant water intake, we injected the GLP-1 receptor agonist exendin-4 (Ex-4) into three brain areas known to express GLP-1 receptors, and measured subsequent water intake. Ex-4 reduced water consumption when injected into the paraventricular hypothalamic nucleus (PVH) and nucleus of the solitary tract (NTS), but not when injected into the nucleus accumbens (NAc). Using the effective response after injection into the PVH as a guide, we examined the connection between the NTS - the site of endogenous central GLP-1 production - and the PVH. Retrograde tracing combined with Fos immunohistochemistry suggested intake-induced activity in PVH-projecting NTS cells. To test the hypothesis that this pathway is important in the termination of drinking, we chemogenetically activated PVH-projecting hindbrain cells. Interestingly, activation of this population of cells increased water intake, calling into question the heterogeneity of the pathway with respect to the control of fluid intake. Taken together, we conclude that the PVH is a site of action for GLP-1 receptor activation in the inhibition of water intake, but suspect that endogenous GLP-1 in NTS-to-PVH projections may be counterbalanced by a parallel pathway that either activates or maintains already activated water intake.

A phase II study of tivozanib in patients with metastatic and nonresectable soft-tissue sarcomas.

Background: Soft tissue sarcomas (STSs) overexpress vascular endothelial growth factors (VEGF) and VEGF-receptors (VEGFR) activation have been associated with tumor aggressiveness. Tivozanib is a potent small molecule tyrosine kinase inhibitor against VEGFR1-3, with activity against PDGFRα/ß and cKIT. The primary endpoint of this study was progression free survival (PFS) rate at 16 weeks. Secondary end points were overall survival (OS), response rate, safety and correlative studies. Patients and methods: A Simon two-stage phase II trial was performed using tivozanib given orally at 1.5 mg daily, 3 week on 1 week off on a 28 day cycle until disease progression or intolerable toxicity. Results: Fifty-eight patients were enrolled and treated with tivozanib. Leiomyosarcoma was the most common STS histological type in our cohort (47%) and 27 patients (46%) had received at least 3 lines of therapy prior to study entry. Up to 24 patients (41%) had prior VEGF targeted therapies. Partial response and stable disease were observed in 2 (3.6%) and 30 (54.5%) patients. The 16 week PFS rate was 36.4% [95% confidence interval (CI) 23.7-49.1] and a median PFS of 3.5 months (95% CI 1.8-3). Median OS observed was 12.2 months (95% CI 8.1-16.8). The most frequent all grade toxicities were fatigue (48.3%), hypertension (43.1%), nausea (31%) and diarrhea (27.6%). The most common grade three toxicity was hypertension (22.4%). Correlative studies demonstrate no correlation between the expression of VEGFR 1, 2 or 3, PDGFRα/ß or FGF, and activity of tivozanib. Conclusion: Tivozanib was well tolerated and showed antitumor activity with a promising median PFS and PFS rate at 4 months in a heavily pretreated population of metastatic STSs. Our results support further studies to assess the clinical efficacy of tivozanib in STS. Clinical Trial Number: NCT01782313.

Curvature correction to the mobility of fluid membrane inclusions.

Using rigorous low-Reynolds-number hydrodynamic theory on curved surfaces, we provide, via a Stokeslet-type approach, a general and concise expression for the leading-order curvature correction to the canonical, planar, Saffman-Delbrück value of the diffusion constant for a small inclusion embedded in an arbitrarily (albeit weakly) curved fluid membrane. In order to demonstrate the efficacy and utility of this general result, we apply our theory to the specific case of calculating the diffusion coefficient of a locally curvature inducing membrane inclusion. By including both the effects of inclusion and membrane elasticity, as well as their respective thermal shape fluctuations, excellent agreement is found with recently published experimental data on the surface tension dependent mobility of membrane bound inclusions.

Effect of capping protein on a growing filopodium.

Filopodia, or the growth of bundles of biological fibers outwards from a biological cell surface while enclosed in a membrane tube, are implicated in many processes vital to life. This study models the effect of capping protein on such filopodia, paying close attention to the polymerization dynamics of biological fiber bundles within long membrane tubes. Due to the effects of capping protein, the number of fibers in the filopodium bundle decreases down the length of the enclosing membrane tube. This decrease in the number of fibers down the length of a growing filopodium is found to have profound implications for the dynamics and stability of filopodia in general. This study theoretically finds that the presence of even a relatively modest amount of capping protein can have a large effect on the growth of typical filopodia, such as can be found in fibroblasts, keratocytes, and neuronal growth cones. As an illustration of this modeling work, this study investigates the striking example of the acrosomal reaction in the sea cucumber Thyone, whose filopodia can grow remarkably quickly to approximately 90 mum in approximately 10 s, and where the number of fibers is known to decrease down the length of the filopodium, presumably due to progressive fiber end-capping occurring as the filopodium grows. Realistic future dynamical theories for filopodium growth are likely to rely on an accurate treatment of the kinds of capping protein effects analyzed in this work.

Convection-enhanced drug delivery of interleukin-4 Pseudomonas exotoxin (PRX321): increased distribution and magnetic resonance monitoring.

Convection-enhanced drug delivery (CED) enables achieving a drug concentration within brain tissue and brain tumors that is orders of magnitude higher than by systemic administration. Previous phase I/II clinical trials using intratumoral convection of interleukin-4 Pseudomonas exotoxin (PRX321) have demonstrated an acceptable safety and toxicity profile with promising signs of therapeutic activity. The present study was designed to assess the distribution efficiency and toxicity of this PRX321 using magnetic resonance imaging (MRI) and to test whether reformulation with increased viscosity could enhance drug distribution. Convection of low- [0.02% human serum albumin (HSA)] and high-viscosity (3% HSA) infusates mixed with gadolinium-diethylenetriamine pentaacetic acid and PRX321 were compared with low- and high-viscosity infusates without the drug, in normal rat brains. MRI was used for assessment of drug distribution and detection of early and late toxicity. Representative brain samples were subjected to histological examination. Distribution volumes calculated from the magnetic resonance images showed that the average distribution of 0.02% HSA was larger than that of 0.02% HSA with PRX321 by a factor of 1.98 (p < 0.02). CED of 3.0% HSA, with or without PRX321, tripled the volume of distribution compared with 0.02% HSA with PRX321 (p < 0.015). No drug-related toxicity was detected. These results suggest that the impeded convection of the PRX321 infusate used in previous clinical trials can be reversed by increasing infusate viscosity and lead to tripling of the volume of distribution. This effect was not associated with any detectable toxicity. A similar capability to reverse impeded convection was also demonstrated in a CED model using acetic acid. These results will be implemented in an upcoming phase IIb PRX321 CED trial with a high-viscosity infusate.

Analysis of the Escherichia coli genome: DNA sequence of the region from 84.5 to 86.5 minutes.

The DNA sequence of 91.4 kilobases of the Escherichia coli K-12 genome, spanning the region between rrnC at 84.5 minutes and rrnA at 86.5 minutes on the genetic map (85 to 87 percent on the physical map), is described. Analysis of this sequence identified 82 potential coding regions (open reading frames) covering 84 percent of the sequenced interval. The arrangement of these open reading frames, together with the consensus promoter sequences and terminator-like sequences found by computer searches, made it possible to assign them to proposed transcriptional units. More than half the open reading frames correlated with known genes or functions suggested by similarity to other sequences. Those remaining encode still unidentified proteins. The sequenced region also contains several RNA genes and two types of repeated sequence elements were found. Intergenic regions include three "gray holes," 0.6 to 0.8 kilobases, with no recognizable functions.

Cross-contamination of cells in culture.

Lists are presented of references to all known publications describing cell properties that serve to characterize (i) known strains of HeLa and purported human cell lines indicated as HeLa contaminants, (ii) strains of human cell lines contaminated with human but non-HeLa cells, and (iii) strains of cells contaminated by cells from one or more other species. Frequencies of cell cross-contaminations are cited and references are presented to relatively simple techniques that could serve to detect such contamination.

UK National Audit of Sexual History-taking: case-notes audit.

A national audit of sexual history-taking was conducted in genitourinary medicine clinics in the UK in 2008. Data were aggregated by region and clinic, allowing practice to be compared between regions, as well as to national averages and against national Guidelines. In this paper the case-notes of 4121 patients were audited. A high proportion of the case-notes were deemed to be completely legible. In other respects there is considerable inter-regional variation in the adherence to national Guidelines. Interventions are especially required to improve documentation of practice in discussing condom use, HIV risk assessment, offer of a chaperone and assessment for hepatitis B vaccination and hepatitis C testing, and issues concerning sexual contacts.

UK National Audit of Sexual History-taking: clinic policies audit.

Provision of a confidential, private environment for sexual history-taking was provided in almost all clinics. However, less than half of the clinics had a policy displayed about their confidentiality policy in waiting areas, although more had this available by other means. About two-thirds of clinic information/advertising literature included information about the need to take a sexual history. Sixty percent of clinics assessed clinician communication skills as part of service quality. Most clinics had policies relating to patients whose first language is not English, but only around half of clinics had policies for hearing difficulties and learning difficulties. Policies are also lacking in some clinics for documentation of the offer of chaperones and assessment of the competency of under-16-year-olds to consent to history-taking and examination.

beta-catenin: molecular plasticity and drug design.

The protein beta-catenin is an essential component of intercellular junctions and the Wnt growth factor signaling pathway. In many cancers, mutation of Wnt pathway components leads to activation of oncogenes by the beta-catenin-Tcf transcription factor complex. This complex is therefore an attractive target for anti-cancer drugs, but any such compound must selectively interfere with the beta-catenin-Tcf complex without disrupting other essential interactions of beta-catenin. Recent structural and biochemical studies have probed the molecular basis of ligand interaction by beta-catenin, and highlighted the possibilities and challenges of designing inhibitors of the beta-catenin-Tcf complex.

Transport of solid bodies along tubular membrane tethers.

We study the crucial role of membrane fluctuations in maintaining a narrow gap between a fluid membrane tube and an enclosed solid particle. Solvent flows can occur in this gap, hence giving rise to a finite particle mobility along the tube. While our study has relevance for how cells are able to transport large organelles or other cargo along connecting membrane tubes, known as tunneling nanotubes, our calculations are also framed so that they can be tested by a specific in vitro experiment: A tubular membrane tether can be pulled from a membrane reservoir, such as an aspirated Giant Unilamellar Vesicle (GUV), e.g. using a conjugated bead that binds to the membrane and is held in a laser trap. We compute the subsequent mobility of colloidal particles trapped in the tube, focusing on the case when the particle is large compared to the equilibrium tube radius. We predict that the particle mobility should scale as ∼ σ-2/3, with σ the membrane tension.

Mixed Solid and Cystic Mass in an Infant.

Desmoplastic infantile tumors are rare supratentorial brain tumors that occur in pediatric patients. Desmoplastic infantile tumors are made up of 2 subtypes: desmoplastic infantile gangliogliomas and desmoplastic infantile astrocytomas. Desmoplastic infantile tumors are often identifiable on imaging on the basis of multiple characteristics. Nevertheless, pathologic analysis is required to confirm the diagnosis, particularly when the imaging features are atypical. Here, the radiology findings, surgical approach and subsequent management, and pathology of a desmoplastic infantile ganglioglioma are described.

National study of HIV testing in men who have sex with men attending genitourinary clinics in the United Kingdom.

OBJECTIVES: To determine what proportion of men who have sex with men (MSM) attending genitourinary medicine (GUM) clinics are offered and accept an HIV test and to examine clinic and patient characteristics associated with offer and uptake. METHODS: A cross-sectional study of all GUM clinics in the United Kingdom, involving a case note review of up to 30 patient records per clinic and the completion of a clinic policy form. RESULTS: Overall, 86% of MSM were offered a test and of those 82% accepted a test. Attending with symptoms of a sexually transmitted infection (STI), fewer numbers of partners in the past three months and having tested previously were all independently associated with a decreased likelihood of being offered a test. Attending with symptoms of an STI, increasing age, never having had a risk from unprotected anal intercourse or a previous HIV test and increasing time to wait for results were all independently associated with a decreased likelihood of a patient accepting a test. Only a quarter of clinics reported a written policy for HIV testing intervals among MSM; however, all clinics reported offering testing to all new MSM patients at first screening. The testing policy for re-attending patients was less clear. CONCLUSIONS: Testing must reach those at most risk and those less likely to test in order to reduce further the proportion of undiagnosed HIV infection. This study suggests that opportunities to detect infection may be being missed and a move towards universal testing of all MSM attending with a new episode, as well as testing within the window period, is recommended.

Theory of simple biochemical "shape recognition" via diffusion from activator coated nanoshapes.

Inspired by recent experiments, we model the shape sensitivity, via a typical threshold initiation response, of an underlying complex biochemical reaction network to activator coated nanoshapes. Our theory re-emphasizes that shape effects can be vitally important for the onset of functional behavior in nanopatches and nanoparticles. For certain critical or particular shapes, activator coated nanoshapes do not evoke a threshold response in a complex biochemical network setting, while for different critical or specific shapes, the threshold response is rapidly achieved. The model thus provides a general theoretical understanding for how activator coated nanoshapes can enable a chemical system to perform simple "shape recognition," with an associated "all or nothing" response. The novel and interesting cases of the chemical response due to a nanoshape that shrinks with time is additionally considered, as well as activator coated nanospheres. Possible important applications of this work include the initiation of blood clotting by nanoshapes, nanoshape effects in nanocatalysis, physiological toxicity to nanoparticles, as well as nanoshapes in nanomedicine, drug delivery, and T cell immunological response. The aim of the theory presented here is that it inspires further experimentation on simple biochemical shape recognition via diffusion from activator coated nanoshapes.

Linear rheology as a potential monitoring tool for sputum in patients with Chronic Obstructive Pulmonary Disease (COPD).

BACKGROUND: The rheological properties of sputum may influence lung function and become modified in disease. OBJECTIVE: This study aimed to correlate the viscoelastic properties of sputum with clinical data on the severity of disease in patients with chronic obstructive pulmonary disease (COPD). METHODS: Sputum samples from COPD patients were investigated using rheology, simple mathematical modelling and Scanning Electron Microscopy (SEM). The samples were all collected from patients within two days of their admission to Prince Philip Hospital due to an exacerbation of their COPD. Oscillatory and creep rheological techniques were used to measure changes in viscoelastic properties at different frequencies over time. RESULTS: COPD sputum was observed to behave as a viscoelastic solid at all frequencies studied. Comparing the rheology of exacerbated COPD sputum with healthy sputum (not diagnosed with a respiratory disease) revealed significant differences in response to oscillatory shear and creep-recovery experiments, which highlights the potential clinical benefits of better understanding sputum viscoelasticity. A common power law model G(t)=G0(tτ0)-m was successfully fitted to experimental rheology data over the range of frequencies studied. CONCLUSIONS: A comparison between clinical data and the power law index m obtained from rheology, suggested that an important possible future application of this parameter is as a potential biomarker for COPD severity.

The novel endocannabinoid receptor GPR55 is activated by atypical cannabinoids but does not mediate their vasodilator effects.

BACKGROUND AND PURPOSE: Atypical cannabinoids are thought to cause vasodilatation through an as-yet unidentified 'CBx' receptor. Recent reports suggest GPR55 is an atypical cannabinoid receptor, making it a candidate for the vasodilator 'CBx' receptor. The purpose of the present study was to test the hypothesis that human recombinant GPR55 is activated by atypical cannabinoids and mediates vasodilator responses to these agents. EXPERIMENTAL APPROACH: Human recombinant GPR55 was expressed in HEK293T cells and specific GTPgammaS activity was monitored as an index of receptor activation. In GPR55-deficient and wild-type littermate control mice, in vivo blood pressure measurement and isolated resistance artery myography were used to determine GPR55 dependence of atypical cannabinoid-induced haemodynamic and vasodilator responses. KEY RESULTS: Atypical cannabinoids O-1602 and abnormal cannabidiol both stimulated GPR55-dependent GTPgammaS activity (EC50 approximately 2 nM), whereas the CB1 and CB2-selective agonist WIN 55,212-2 showed no effect in GPR55-expressing HEK293T cell membranes. Baseline mean arterial pressure and heart rate were not different between WT and GPR55 KO mice. The blood pressure-lowering response to abnormal cannabidiol was not different between WT and KO mice (WT 20+/-2%, KO 26+/-5% change from baseline), nor was the vasodilator response to abnormal cannabidiol in isolated mesenteric arteries (IC50 approximately 3 micro M for WT and KO). The abnormal cannabidiol vasodilator response was antagonized equivalently by O-1918 in both strains. CONCLUSIONS: These results demonstrate that while GPR55 is activated by atypical cannabinoids, it does not appear to mediate the vasodilator effects of these agents.

Management of rape/sexual assault cases within genitourinary medicine clinics: results from a study in North Thames.

A regional audit was undertaken to evaluate current practice in the management of survivors of sexual assault (SA) seen in genitourinary (GU) medicine clinics in the North Thames. The majority of the survivors were women. Most were fast-tracked, or seen in dedicated SA clinics. Over 60% of staff had specific training in management of SA. Core services provided included screening and treatment for sexually transmitted infections, emotional support, emergency contraception and hepatitis B vaccination. The sexual health needs of these survivors of SA are being met by most clinics. The development and use of a standardized care proforma across the region may be a means to further improve the care provided.

A national audit of gonorrhoea management.

A national audit of gonorrhoea clinic policy and case management was carried out by postal survey on behalf of the National Audit Group of the British Association for Sexual Health and HIV. Ninety-three clinics out of a total of 278 (33%) and 1324 cases were included. The results showed that both the auditable outcome measures listed in the National Guideline for the Management of Gonorrhoea in Adults and the evidence-based outcome standards recently published by Low et al. were broadly being met.

DNA damage recognition and repair pathway coordination revealed by the structural biochemistry of DNA repair enzymes.

Cells have evolved distinct mechanisms for both preventing and removing mutagenic and lethal DNA damage. Structural and biochemical characterization of key enzymes that function in DNA repair pathways are illuminating the biological and chemical mechanisms that govern initial lesion detection, recognition, and excision repair of damaged DNA. These results are beginning to reveal a higher level of DNA repair coordination that ensures the faithful repair of damaged DNA. Enzyme-induced DNA distortions allow for the specific recognition of distinct extrahelical lesions, as well as tight binding to cleaved products, which has implications for the ordered transfer of unstable DNA repair intermediates between enzymes during base excision repair.