Residues 2 to 7 of α-synuclein regulate amyloid formation via lipid-dependent and lipid-independent pathways.

Amyloid formation by α-synuclein (αSyn) occurs in Parkinson's disease, multiple system atrophy, and dementia with Lewy bodies. Deciphering the residues that regulate αSyn amyloid fibril formation will not only provide mechanistic insight but may also reveal targets to prevent and treat disease. Previous investigations have identified several regions of αSyn to be important in the regulation of amyloid formation, including the non-amyloid-ß component (NAC), P1 region (residues 36 to 42), and residues in the C-terminal domain. Recent studies have also indicated the importance of the N-terminal region of αSyn for both its physiological and pathological roles. Here, the role of residues 2 to 7 in the N-terminal region of αSyn is investigated in terms of their ability to regulate amyloid fibril formation in vitro and in vivo. Deletion of these residues (αSynΔN7) slows the rate of fibril formation in vitro and reduces the capacity of the protein to be recruited by wild-type (αSynWT) fibril seeds, despite cryo-EM showing a fibril structure consistent with those of full-length αSyn. Strikingly, fibril formation of αSynΔN7 is not induced by liposomes, despite the protein binding to liposomes with similar affinity to αSynWT. A Caenorhabditis elegans model also showed that αSynΔN7::YFP forms few puncta and lacks motility and lifespan defects typified by expression of αSynWT::YFP. Together, the results demonstrate the involvement of residues 2 to 7 of αSyn in amyloid formation, revealing a target for the design of amyloid inhibitors that may leave the functional role of the protein in membrane binding unperturbed.

Endoport-Guided Endoscopic Excision of Intraaxial Brain Tumors.

OBJECTIVE: Transcortical approaches using a spatula-based retraction system have traditionally been used for the microsurgical resection of deep-seated intraventricular and parenchymal brain tumors. Recently, transparent cylindrical or tubular retractors have been developed to provide a stable corridor to access deeper brain lesions and perform bimanual microsurgical resection. The flexible endoports minimize brain retraction injury during surgery and, along with the superior vision of endoscopes, offer several advantages over standard microsurgery. In this chapter, we describe the surgical technique of the endoport-guided endoscopic excision of deep-seated intraaxial brain tumors. METHODS: The endoscopic endoport technique that we use at our institution for the surgical management of intraventricular and intraparenchymal brain tumors has been described in detail with illustrative cases. RESULTS: Results from the literature review of intraventricular and intraparenchymal port surgery were analyzed, and the feasibility and safety of this technique were discussed. Surgical complication avoidance and management were highlighted. The port technique offers numerous potential advantages, including (1) reducing focal brain injury by distributing retraction forces homogenously, (2) minimizing white matter disruption and the risk of fascicle injury during cannulation, (3) ensuring the stability of the surgical corridor during the procedure, (4) preventing inadvertent expansion of the corticectomy and white fiber tract dissection throughout surgery, and (5) protecting the surrounding tissues against iatrogenic injuries caused by instrument entry and reentry. CONCLUSION: The endoport-assisted endoscopic technique is safe and offers an effective alternative option for the resection of intraventricular and intraparenchymal lesions.

Endoneurosurgical Resection of Parenchymal and Intraventricular Lesions Using Tubular Retraction System.

OBJECTIVE: Endoscopic surgery has emerged in the recent years as an alternative to the conventional microsurgical approaches for removal of the deep-seated brain and intraventricular tumors. Endoport has enhanced the tumor access and visualization without any significant brain retraction. In this chapter, we describe the surgical technique of the endoscopic excision of the deep-seated intra-axial brain tumors using tubular retraction system with review of the literature. METHODS: The endoscopic endoport technique that we use at our institution for the surgical management of intraventricular and intraparenchymal brain tumors has been described in details with illustrations. RESULTS: Results from the literature review of brain parenchymal and intraventricular port surgery were analyzed, and the feasibility and safety of this technique were discussed. Surgical complication avoidance and management were highlighted. The port technique offers numerous potential advantages, including: (1) reducing focal brain injury by distributing retraction forces homogenously; (2) minimizing white matter disruption and the risk of fascicles injury during cannulation; (3) ensuring stability of the surgical corridor during the procedure; (4) preventing inadvertent expansion of the corticectomy and white fiber tract dissection throughout surgery; (5) protecting the surrounding tissues against iatrogenic injuries caused by instrument entry and reentry. CONCLUSION: The endoport-assisted endoscopic technique is a safe and minimally invasive method that offers an effective alternative option for resection of intraventricular and parenchymal brain lesions. Excellent outcome comparable to other surgical approaches can be achieved with acceptable complications.

Morphometric Study on Wormian Bone of Dry Adult Skull of Nepalese Population.

Background Accessory (supernumerary bone) is small irregular worm like bone. These bones are also known as wormian bone. Accessory bone develops when additional ossification centers appear and form extra bones. Many bones develop from several ossification centers of ossification and these separate parts normally fuse. Sometimes one of these centers fails to fuse with main bone. Circumscribed areas of bone are seen along the sutures of the cranium where flat bones about, particularly related to parietal bone. Objective To investigate presence and to determine morphologic and morphometric characteristics of wormian (sutural) bones. Method The study was conducted on 25 dry human skulls with unknown gender, ethnicity and race in Department of Anatomy, School of Basic Sciences, Kailashnagar, Bharatpur-5, Chitwan Nepal. The study was conducted on 25 dry human skulls with unknown gender, ethnicity and race in Department of Anatomy, School of Basic Sciences, Kailashnagar, Bharatpur-5, Chitwan Nepal. The deformed skull and skull of pediatrics age group are excluded. The location, shape, number and side of Wormian bone are determined. The SPSS 20 program and descriptive statistical method analysis were used for data analysis. Result Total 25 adult dry skulls were observed in the study. Both sides of skull were observed. Out of 25 skulls Wormian bones are not found in left sided three lambdoidal suture (four percent). Conclusion The knowledge of Wormian bones plays a major role for the neurosurgeons, neuroanatomists, radiologists, forensic experts and anthropologist. Presence of few bones are normal. But multiple Wormian bones need attention as it may have underlying skeletal or central nervous system pathology. In radiographs they mimic fracture lines. Wormian bone at pterion may produce complications in neurosurgical procedures like burr holes.

Ag-enriched TiO2 nanocoating apposite for self-sanitizing/ self-sterilizing/ self-disinfecting of glass surfaces.

The excellent strategy to mitigate the spread of the COVID-19 pandemic is to inhibit the transmission of the SARS-CoV-2. Since fomites are one of the vital routes of coronaviral transmission, disinfecting of fomites play a pivotal role in curbing its survival on the contaminated surfaces. Available commercial disinfectants cannot keep the contaminated surfaces sanitized all the time. Self-disinfecting ability of Ag-enriched TiO2 nanocoating due to its superb photocatalytic efficiency can effectively reduce infections caused by spread of pathogens at public places. Anatase Ag-TiO2 nanocoatings synthesized by sol-gel process at 0.5, 1.5, and 2.5% enriching concentrations were casted on glass substrates by spin-coating technique and subsequently annealed at 650 °C. The morphological shape, crystallographic structure, light absorbance, photo-luminosity, vibrational modes, and functional groups of Ag-TiO2 nanocoating on glass surface were studied by FE-SEM, GIXRD, UV-Visible, Photoluminescence, Raman, and FTIR spectroscopy. The developed anatase Ag-TiO2 nanocoatings manifested to improve photocatalytic disinfecting performance due to the achieved small crystallite size of 10.5-19.2 nm, diminished band gap energy of 2.56-2.60 eV, elevated surface area of 0.802-1.470 ×105 cm2/g, and enhanced light absorbance. Among the enriched specimens, 0.5% Ag-TiO2 nanocoatings predicted an overall exalted functionality compared to pristine one.

An Anatomical Variation of Median Artery of Forearm and Palm: Cadaveric Study into its Origin and Course.

Background The median artery (transitory artery) represents the forearm's embryonic arterial axis. At 8th week of gestation retreats into a little canal that supplies the median nerve. Later, ulnar and radial arteries take its place. Adults may still have it in either a palmar or an antebrachial pattern. The persistent median arteries are a long, angular arterial that extends to the hand's palmar surface. The median artery only partially recedes in the antebrachial type. Objective To identify the median artery distribution in the adult Nepalese population. Method Twenty-five adult human cadavers' left and right upper limbs undergone to descriptive research. The persistent median artery was exposed according to the Cunningham's Manual of Practical Anatomy. Result The forearm and hand arteries in each of the fifty upper limbs from the twentyfive formalin-embalmed human cadavers were studied. Among fifty upper limbs, persistent median arteries were found in six (twelve percent) of them. One percent of a cadaver's right and left limbs had bilateral persisting median arteries (ante brachial). Persistent median artery of the ante brachial type that arises from the anterior interosseous artery in a right upper limb. Persistent median artery emerging from the posterior interosseous arteries were visible in one right upper limb. Conclusion The study showed persistent median artery of ante brachial type. The posterior interosseus artery is the source of the majority of antebrachial type. A median artery piercing the median nerve was discovered.

Phase 1b investigation of the MEK inhibitor binimetinib in patients with advanced or metastatic biliary tract cancer.

Background The MAPK pathway plays a central role in regulation of several cellular processes, and its dysregulation is a hallmark of biliary tract cancer (BTC). Binimetinib (MEK162), a potent, selective oral MEK1/2 inhibitor, was assessed in patients with advanced BTC. Patients and Methods An expansion cohort study in patients who received ≤1 line of therapy for advanced BTC was conducted after determination of the maximum tolerated dose in this Phase 1 trial. Patients received binimetinib 60 mg twice daily. The primary objectives were to characterize the safety profile and pharmacokinetics of binimetinib in advanced BTC. Secondary objectives included assessment of clinical efficacy, changes in weight and lean body mass, and pharmacodynamic effects. Tumor samples were assessed for mutations in relevant genes. Results Twenty-eight patients received binimetinib. Common adverse events (AEs) were mild, with rash (82%) and nausea (54%) being most common. Two patients experienced grade 4 AEs, one generalized edema and the other pulmonary embolism. The pharmacokinetics in this patient population were consistent with those previously reported (Bendell JC et al., Br J Cancer 2017;116:575-583). Twelve patients (43%) experienced stable disease and two had objective responses (1 complete response, 1 partial response) per Response Evaluation Criteria in Solid Tumors and stable metabolic disease by positron emission tomography/computed tomography. Most patients (18/25; 72%) did not have KRAS, BRAF, NRAS, PI3KCA, or PTEN mutations, nor was there correlation between mutation status and response. The average non-fluid weight gain was 1.3% for lean muscle and 4.7% for adipose tissue. Conclusion Binimetinib was well tolerated and showed promising evidence of activity in patients with BTC. Correlative studies suggested the potential for binimetinib to promote muscle gain in patients with BTC.

Production of membrane proteins for characterisation of their pheromone-sensing and antimicrobial resistance functions.

Despite the importance of membrane proteins in cellular processes, studies of these hydrophobic proteins present major technical challenges, including expression and purification for structural and biophysical studies. A modified strategy of that proposed previously by Saidijam et al. (2005) and others, for the routine expression of bacterial membrane proteins involved in environmental sensing and antimicrobial resistance (AMR), is proposed which results in purification of sufficient proteins for biophysical experiments. We report expression successes amongst a collection of enterococcal vancomycin resistance membrane proteins: VanTG, VanTG-M transporter domain, VanZ and the previously characterised VanS (A-type) histidine protein kinase (HPK). Using the same strategy, we report on the successful amplification and purification of intact BlpH and ComD2 HPKs of Streptococcus pneumoniae. Near-UV circular dichroism revealed both recombinant proteins bound their pheromone ligands BlpC and CSP2. Interestingly, CSP1 also interacted with ComD. Finally, we evaluate the alternative strategy for studying sensory HPKs involving isolated soluble sensory domain fragments, exemplified by successful production of VicKESD of Enterococcus faecalis VicK. Purified VicKESD possessed secondary structure post-purification. Thermal denaturation experiments using far-UV CD, a technique which can be revealing regarding ligand binding, revealed that: (a) VicKESD denaturation occurs between 15 and 50 °C; and (b) reducing conditions did not detectably affect denaturation profiles suggesting reducing conditions per se are not directly sensed by VicKESD. Our findings provide information on a modified strategy for the successful expression, production and/or storage of bacterial membrane HPKs, AMR proteins and sensory domains for their future crystallisation, and ligand binding studies.

Impacts of counseling on knowledge, attitude and practice of medication use during pregnancy.

BACKGROUND: Counseling has a significant role in improving knowledge, attitude and practice outcomes of pregnant women towards medication use. Proper counseling thus could be beneficial to prevent any medication related misadventure during pregnancy. The present study was aimed to assess the knowledge, attitude and practice (KAP) of pregnant women towards their medications, to provide counseling regarding their understanding of medication use during pregnancy and evaluate the impacts of such counseling. METHODS: Pre- post interventional (counseling) study was conducted at Manipal Teaching Hospital, Nepal among pregnant women who presented with complication and were prescribed at least one medication. A total of 275 pregnant women were included in the study. A structured questionnaire was used to assess the knowledge, attitude and practice of pregnant women before and after counseling. The impacts of counseling were then evaluated using suitable statistical methods. RESULTS: Of the total participants 229 completed the post counseling survey. Majority of the participants were in the age group 20-24 (43.2%), primigravida (59.4%) and in third trimester (58.6%). Housewives comprised 61.1% of participants and majority had received a University degree (33.2%). The mean and median scores assessed before counseling showed that there was no significant difference in the KAP scores with respect to age, trimester and gravidity whereas KAP scores with respect to occupation and level of education were statistically significant. There was an increase in mean and median KAP scores after counseling and the impacts of counseling was found to be statistically significant (p = <0.001). CONCLUSION: Counseling had a positive impact on knowledge, attitude and practice of pregnant women towards medication and thus it could be considered a suitable method to encourage safe medication during pregnancy.

Intimate partner violence as a factor associated with risky sexual behaviours and alcohol misuse amongst men in South Africa.

Globally intimate partner violence (IPV) is a public health problem that can be perpetrated by both males and females, although males are more likely to inflict severe IPV-related injuries on their female partners. In low- and middle-income countries like South Africa, few studies have conducted research to determine whether IPV perpetration by men may be a risk factor for engaging in other risk behaviours. The aim of this study is to determine whether IPV perpetration by men is a risk factor for engaging in other risk behaviours with a particular focus on risky sexual behaviours and alcohol misuse. The data for this study were drawn from a multilevel intervention study, which addressed the nexus of alcohol abuse and HIV prevention among men in South Africa. Men were screened and recruited from informal drinking places within 12 communities situated in one of the oldest, predominantly Xhosa-speaking African townships in Cape Town. Univariate and multivariate logistic regression models were used to analyse the associations between IVP and potential explanatory variables. Of the 975 men included in the survey, 39.9% reported to have been involved in Intimate Partner Violence. IPV perpetration was significantly more likely among men who reported having a child [OR 1.51 (1.07-2.14) p = .019], having a casual sexual partner [OR 1.51 (1.11-2.05) p = .008], and those with possible alcohol dependence [OR 3.46 (1.17-10.20) p = .024]. IPV was significantly less likely among men with matric educational qualification than those with no education [OR 0.30 (95% CI: 0.09-1.02) p = .053] and among those who reported using a condom at last sex [OR 0.69 (0.50-0.97) p = .034]. We therefore recommend that interventions aimed at reducing IPV need to address risky sexual and drinking behaviours amongst men simultaneously, while also focusing on intimate relationship power dynamics and gendered norms amongst couples.

Medication utilization pattern for management of pregnancy complications: a study in Western Nepal.

BACKGROUND: Drugs used during pregnancy can adversely affect the health and life of the mother and unborn child. However, the fact that drugs are needed to mitigate complications during pregnancy cannot be avoided. The present study was designed to identify the common complications during pregnancy and assess the medications that have been used to mitigate those complications in an attempt to improve drug prescribing during pregnancy. METHODS: A hospital based cross sectional study was conducted at Manipal Teaching Hospital, Nepal in 275 pregnant women presenting with at least one complication and the drugs prescribed for the management of those complications were analyzed. RESULTS: Majority of the patients in this study were in the age group 20-24 (44 %) and in the third trimester (53.8 %). Maximum patients complained pain (back, abdominal, lower abdominal, neck, pelvic) as primary complication (24.3 %) which was followed by nausea/vomiting, upper respiratory tract complications, acid reflux disease and others. Of the total prescriptions eighty six (86) did not have any medicines prescribed to the patients except multivitamins and nutritional supplements. The average drugs prescribed per patient was 2.78 in outpatient setting and 5.41 in in-patients. Ranitidine, hyoscine butylbromide, paracetamol were the most frequently prescribed medications. Antimicrobials comprised 12.8 % of total drugs prescribed and 18 % of total drugs were fixed dose combinations. Two hundred and thirty four (234) prescriptions out of 275 were prescribed by brand names. Most of the prescribed drugs were from FDA pregnancy category B and C. CONCLUSION: The present finding showed that pregnant patients were prescribed medications almost only when necessary and those considered safe during pregnancy were chosen to a large extent. However, few teratogenic drugs (2.49 % of total drugs prescribed) were also found to be prescribed which might need further assessments.

Isolation of microsatellite loci for Rhodiola alsia (Crassulaceae), an important ethno-medicinal herb endemic to the Qinghai-Tibetan plateau.

Rhodiola alsia, which has been used widely in traditional Chinese medicine for a considerable time, grows on moist habitats at high altitude near the snow line. Microsatellite loci were developed for R. alsia to investigate its population genetics. In total, 17 polymorphic microsatellites were developed based on ESTs from the Illumina HiSeq(TM) 2000 platform. The microsatellite loci were checked for variability using 80 individuals of R. alsia sampled from four locations on the Qinghai-Tibet Plateau. The total number of alleles per locus ranged from 10 to 20, and the observed heterozygosity ranged from 0.000 to 1.000. The null allele frequency ranged from 0.000 to 0.324. These microsatellites are expected to be helpful in future studies of population genetics in R. alsia and related species.

Mutations in the N-domain of aryl hydrocarbon receptor interacting protein affect interactions with heat shock protein 90ß and phosphodiesterase 4A5.

The aryl hydrocarbon receptor interacting protein (AIP) is a cytoplasmic molecular co-chaperone and tumour suppressor that assists in protein stability and complex formation involving the aryl hydrocarbon receptor. Germline mutations in the AIP gene predispose to pituitary tumourigenesis with patients exhibiting an aggressive clinical phenotype. Full length AIP proteins harbouring N-domain mutations (R9Q, R16H, V49 M and K103R) were purified from E.coli utilizing a methodology that maintained structural integrity and monomeric stability. Mutations did not significantly affect the thermal stability of the protein and caused no overall disruptive effect in the protein structure. The mutations studied lowered the binding affinity of AIP towards two of its binding partners; heat shock protein 90ß and phosphodiesterase 4A5 (PDE4A5). The inhibition of phosphodiesterase activity by AIP was also greatly reduced by all mutants. While previously published data has mainly concentrated on the tetratricopeptide repeats of the C-domain of AIP, we present clear evidence that AIP N-domain mutations play a significant role in two protein:protein interactions with partner proteins. The complex interactome of AIP suggests that any observable change in one or more of its binding partners cannot be disregarded as it may have repercussions on other biochemical pathways.

Novel Uses of Methadone Under the "72-Hour Rule" to Facilitate Transitions of Care and Low-Dose Buprenorphine Induction in an Outpatient Bridge Clinic.

BACKGROUND: Federal regulations restrict methadone for opioid use disorder (OUD) treatment to licensed opioid treatment programs (OTPs). However, providers in other settings can administer methadone for opioid withdrawal under the "72-hour rule" while linking to further care. Prior work has demonstrated that methadone initiation in a low-barrier bridge clinic is associated with high OTP linkage and 1-month retention rates. We describe 2 other novel applications of the 72-hour rule in which methadone withdrawal management facilitated linkage to inpatient hospitalization and outpatient buprenorphine induction. CASE PRESENTATIONS: Patient 1 was a 46-year-old woman with OUD complicated by serious injection-related infections. Severe opioid withdrawal limited her ability to tolerate emergency department wait times and receive inpatient care. We administered methadone for opioid withdrawal in an outpatient bridge clinic immediately before emergency department referral; this enabled hospital admission for intravenous antibiotics and anticoagulation. Patient 2 was a 36-year-old man with OUD desiring buprenorphine treatment. He had been unable to complete traditional buprenorphine induction without experiencing precipitated withdrawal. Thus, we recommended a low-dose buprenorphine induction overlapping with a full opioid agonist. Given the patient's preference to stop using fentanyl immediately, he received 72 hours of methadone for withdrawal treatment during the induction phase and successfully transitioned to buprenorphine without significant concomitant fentanyl use. CONCLUSION: In addition to facilitating OTP linkage, on-demand 72-hour methadone administration for opioid withdrawal can reduce barriers to acute medical care and buprenorphine treatment.

Advanced Maternal Age Affects the Cryosusceptibility of Ovulated but not In Vitro Matured Mouse Oocytes.

Oocyte cryopreservation is offered to women of various age groups for both health and social reasons. Oocytes derived from either controlled ovarian stimulation or in vitro maturation (IVM) are cryopreserved via vitrification. As maternal age is a significant determinant of oocyte quality, there is limited data on the age-related susceptibility of oocytes to the vitrification-warming procedure alone or in conjunction with IVM. In the present study, metaphase II oocytes obtained from 2, 6, 9, and 12 month old Swiss albino mice either by superovulation or IVM were used. To understand the association between maternal age and oocyte cryotolerance, oocytes were subjected to vitrification-warming and compared to non vitrified sibling oocytes. Survived oocytes were evaluated for mitochondrial potential, spindle integrity, relative expression of spindle checkpoint protein transcripts, and DNA double-strand breaks. Maturation potential and vitrification-warming survival were significantly affected (p < 0.001 and p < 0.05, respectively) in ovulated oocytes from the advanced age group but not in IVM oocytes. Although vitrification-warming significantly increased spindle abnormalities in ovulated oocytes from advanced maternal age (p < 0.01), no significant changes were observed in IVM oocytes. Furthermore, Bub1 and Mad2 transcript levels were significantly higher in vitrified-warmed IVM oocytes (p < 0.05). In conclusion, advanced maternal age can have a negative impact on the cryosusceptibility of ovulated oocytes but not IVM oocytes in mice.

Dual client binding sites in the ATP-independent chaperone SurA.

The ATP-independent chaperone SurA protects unfolded outer membrane proteins (OMPs) from aggregation in the periplasm of Gram-negative bacteria, and delivers them to the ß-barrel assembly machinery (BAM) for folding into the outer membrane (OM). Precisely how SurA recognises and binds its different OMP clients remains unclear. Escherichia coli SurA comprises three domains: a core and two PPIase domains (P1 and P2). Here, by combining methyl-TROSY NMR, single-molecule Förster resonance energy transfer (smFRET), and bioinformatics analyses we show that SurA client binding is mediated by two binding hotspots in the core and P1 domains. These interactions are driven by aromatic-rich motifs in the client proteins, leading to SurA core/P1 domain rearrangements and expansion of clients from collapsed, non-native states. We demonstrate that the core domain is key to OMP expansion by SurA, and uncover a role for SurA PPIase domains in limiting the extent of expansion. The results reveal insights into SurA-OMP recognition and the mechanism of activation for an ATP-independent chaperone, and suggest a route to targeting the functions of a chaperone key to bacterial virulence and OM integrity.

Length weight relationship and condition factor of selected freshwater fish species found in river Ganga, Gomti and Rapti, India.

This study is based on the length-weight relationships (LWRs) of 2148 fishes, belonging to 8 families, 12 genera and 15 freshwater fish species (Wallago attu, Rite rita, Sperato seenghala, Sperota aor, Mostacembalus armatus, Macrognathus puncolus, Gudusia chopra, Clupisoma garua, Puntius sophore, Puntius ticto, Rasbora daniconius, Amblypharyngodon mole, Chanda noma, Colisa fociatus and Colisa sota) captured from river Ganga, Gomti and Rapti during May 2011 to March 2012. The growth coefficient (b) values varied between 1.30 and 3.07, with the mean b = 2.03 at p< 0.001. The condition factor (K) varied considerably from 0.76 and 2.95, with a mean K = 1.43 which may be attributed to different environmental conditions of the river basin. The objective was to evaluate the pattern of LWRs and condition factors of the freshwater fish species of the main Ganga and tributaries which serves as baseline for other tropical Indian rivers and tributaries.

Sculpting conducting nanopore size and shape through de novo protein design.

Transmembrane ß-barrels (TMBs) are widely used for single molecule DNA and RNA sequencing and have considerable potential for a broad range of sensing and sequencing applications. Current engineering approaches for nanopore sensors are limited to naturally occurring channels such as CsgG, which have evolved to carry out functions very different from sensing, and hence provide sub-optimal starting points. In contrast, de novo protein design can in principle create an unlimited number of new nanopores with any desired properties. Here we describe a general approach to the design of transmembrane ß-barrel pores with different diameter and pore geometry. NMR and crystallographic characterization shows that the designs are stably folded with structures close to the design models. We report the first examples of de novo designed TMBs with 10, 12 and 14 stranded ß-barrels. The designs have distinct conductances that correlate with their pore diameter, ranging from 110 pS (~0.5 nm pore diameter) to 430 pS (~1.1 nm pore diameter), and can be converted into sensitive small-molecule sensors with high signal to noise ratio. The capability to generate on demand ß-barrel pores of defined geometry opens up fundamentally new opportunities for custom engineering of sequencing and sensing technologies.

No evidence for the involvement of XMRV or MCV in the pathogenesis of breast cancer.

BACKGROUND: The aetiology of breast cancer remains elusive. A viral aetiology has been proposed, but to date no virus has been conclusively demonstrated to be involved. Recently, two new viruses, namely Merkel cell polyomavirus (MCV) and xenotropic murine leukaemia virus-related virus (XMRV) have been identified and implicated in the pathogenesis of Merkel cell carcinoma (MCC) and familial form of prostate cancer, respectively. METHODS: We examined 204 samples from 58 different cases of breast cancer for presence of MCV or XMRV by PCR. Samples consisted of both malignant and non-malignant tissues. Additionally, we included 6 cases of MCC and 12 cases of prostate cancer as potential controls for MCV and XMRV, respectively. RESULTS: All of the breast cancer samples examined were negative for both MCV and XMRV. However, 4/6 MCC and 2/12 prostate cancer samples were found to be positive for MCV and XMRV, respectively. Sequence analysis of the amplified products confirmed that these sequences belonged to MCV and XMRV. CONCLUSION: We conclude that there is no evidence for the involvement of MCV or XMRV in the pathogenesis of breast cancer. What role these viruses have in the pathogenesis of MCC and prostate carcinomas remains to be demonstrated.

Translational Mini-Review Series on B cell subsets in disease. B cells in multiple sclerosis: drivers of disease pathogenesis and Trojan horse for Epstein-Barr virus entry to the central nervous system?

The recent success of therapies directed at B cells has highlighted their potential as central players in multiple sclerosis (MS) pathogenesis. Exciting new data showed that B cell depletion led to reduced clinical and magnetic resonance imaging (MRI) evidence of disease activity. However, the mechanisms of action remain unknown, but could involve autoantibody production, antigen presentation and/or cytokine production by B cells. Another exciting line of investigation in the field of MS comes from latent infection of memory B cells by Epstein-Barr virus (EBV). These cells are hijacked as 'Trojan horses' and 'smuggle' the virus into the central nervous system (CNS). Thus, these new anti B cell treatments will also be likely to have anti-viral effects. We briefly review recent findings in the field of MS pathogenesis, and highlight promising new targets for therapeutic intervention in MS.