Myelination of peripheral nerves is controlled by PI4KB through regulation of Schwann cell Golgi function.

Better understanding myelination of peripheral nerves would benefit patients affected by peripheral neuropathies, including Charcot-Marie-Tooth disease. Little is known about the role the Golgi compartment plays in Schwann cell (SC) functions. Here, we studied the role of Golgi in myelination of peripheral nerves in mice through SC-specific genetic inactivation of phosphatidylinositol 4-kinase beta (PI4KB), a Golgi-associated lipid kinase. Sciatic nerves of such mice showed thinner myelin of large diameter axons and gross aberrations in myelin organization affecting the nodes of Ranvier, the Schmidt-Lanterman incisures, and Cajal bands. Nonmyelinating SCs showed a striking inability to engulf small diameter nerve fibers. SCs of mutant mice showed a distorted Golgi morphology and disappearance of OSBP at the cis-Golgi compartment, together with a complete loss of GOLPH3 from the entire Golgi. Accordingly, the cholesterol and sphingomyelin contents of sciatic nerves were greatly reduced and so was the number of caveolae observed in SCs. Although the conduction velocity of sciatic nerves of mutant mice showed an 80% decrease, the mice displayed only subtle impairment in their motor functions. Our analysis revealed that Golgi functions supported by PI4KB are critically important for proper myelination through control of lipid metabolism, protein glycosylation, and organization of microvilli in the nodes of Ranvier of peripheral nerves.

In Vivo Half-Life Extension of BMP1/TLL Metalloproteinase Inhibitors Using Small-Molecule Human Serum Albumin Binders.

Reducing the required frequence of drug dosing can improve the adherence of patients to chronic treatments. Hence, drugs with longer in vivo half-lives are highly desirable. One of the most promising approaches to extend the in vivo half-life of drugs is conjugation to human serum albumin (HSA). In this work, we describe the use of AlbuBinder 1, a small-molecule noncovalent HSA binder, to extend the in vivo half-life and pharmacology of small-molecule BMP1/TLL inhibitors in humanized mice (HSA KI/KI). A series of conjugates of AlbuBinder 1 with BMP1/TLL inhibitors were prepared. In particular, conjugate c showed good solubility and a half-life extension of >20-fold versus the parent molecule in the HSA KI/KI mice, reaching half-lives of >48 h with maintained maximal inhibition of plasma BMP1/TLL. The same conjugate showed a half-life of only 3 h in the wild-type mice, suggesting that the half-life extension was principally due to specific interactions with HSA. It is envisioned that conjugation to AlbuBinder 1 should be applicable to a wide range of small molecule or peptide drugs with short half-lives. In this context, AlbuBinders represent a viable alternative to existing half-life extension technologies.

Inflatable penile prosthesis implantation into scarred corporal bodies: timing may decrease postoperative problems.

OBJECTIVES: To compare the rates of intra- and postoperative complications between early (<4 months) or delayed (>4 months) inflatable penile prosthesis (IPP) re-implantation performed after a fibrosis-inducing event. PATIENTS AND METHODS: Cases of IPP re-implantation were performed by a single, high-volume prosthetic surgeon in hospitals domestically and abroad over a 15-year period (2001-2016). The time interval from the precipitating event to operation, intra-operative complications and postoperative complications for up to 1 year after implantation, were recorded. RESULTS: A total of 72 cases of IPP re-implantation were recorded. There were 16 (53%) intraoperative complications in patients who had surgery at <4 months (Group 1) and 23 (55%) in patients operated at >4 months (Group 2). There were four (13%) postoperative complications in Group 1 and 14 (33%) in Group 2. CONCLUSION: Re-implantation of an IPP into fibrotic corporal bodies is associated with less serious postoperative complications when performed within 4 months of the fibrosis-inducing event.

Phos-tag analysis of Rab10 phosphorylation by LRRK2: a powerful assay for assessing kinase function and inhibitors.

Autosomal dominant mutations that activate the leucine-rich repeat kinase 2 (LRRK2) cause inherited Parkinson's disease. Recent work has revealed that LRRK2 directly phosphorylates a conserved threonine/serine residue in the effector-binding switch-II motif of a number of Rab GTPase proteins, including Rab10. Here we describe a facile and robust method to assess phosphorylation of endogenous Rab10 in mouse embryonic fibroblasts (MEFs), lung and spleen-derived B-cells, based on the ability of the Phos-tag reagent to retard the electrophoretic mobility of LRRK2-phosphorylated Rab10. We exploit this assay to show that phosphorylation of Rab10 is ablated in kinase-inactive LRRK2[D2017A] knockin MEFs and mouse lung, demonstrating that LRRK2 is the major Rab10 kinase in these cells/tissue. We also establish that the Phos-tag assay can be deployed to monitor the impact that activating LRRK2 pathogenic (G2019S and R1441G) knockin mutations have on stimulating Rab10 phosphorylation. We show that upon addition of LRRK2 inhibitors, Rab10 is dephosphorylated within 1-2 min, markedly more rapidly than the Ser(935) and Ser(1292) biomarker sites that require 40-80 min. Furthermore, we find that phosphorylation of Rab10 is suppressed in LRRK2[S910A+S935A] knockin MEFs indicating that phosphorylation of Ser(910) and Ser(935) and potentially 14-3-3 binding play a role in facilitating the phosphorylation of Rab10 by LRRK2 in vivo The Rab Phos-tag assay has the potential to significantly aid with evaluating the effect that inhibitors, mutations and other factors have on the LRRK2 signalling pathway.

Methods of conducting effective outreach to private well owners - a literature review and model approach.

Educational outreach programs have the potential to increase the occurrence of private well testing and maintenance behaviors, but are not always able to successfully engage the intended audience and overcome their barriers to change. We conducted a review of literature regarding behavior change and risk communication to identify common barriers to private well stewardship and motivational strategies to encourage change, as well as best practices for communicating with well owners. Results indicated that no specific strategy will be appropriate for all audiences, as different groups of well owners will have different barriers to change. For this reason, educators must develop an understanding of their audience so they are able to identify the most significant barriers to change and select motivational strategies that will directly reduce barriers. Implications for private well outreach programs are discussed.

Pharmacological and genetic targeting of the PI4KA enzyme reveals its important role in maintaining plasma membrane phosphatidylinositol 4-phosphate and phosphatidylinositol 4,5-bisphosphate levels.

Phosphatidylinositol 4-kinase type IIIα (PI4KA) is a host factor essential for hepatitis C virus replication and hence is a target for drug development. PI4KA has also been linked to endoplasmic reticulum exit sites and generation of plasma membrane phosphoinositides. Here, we developed highly specific and potent inhibitors of PI4KA and conditional knock-out mice to study the importance of this enzyme in vitro and in vivo. Our studies showed that PI4KA is essential for the maintenance of plasma membrane phosphatidylinositol 4,5-bisphosphate pools but only during strong stimulation of receptors coupled to phospholipase C activation. Pharmacological blockade of PI4KA in adult animals leads to sudden death closely correlating with the drug's ability to induce phosphatidylinositol 4,5-bisphosphate depletion after agonist stimulation. Genetic inactivation of PI4KA also leads to death; however, the cause in this case is due to severe intestinal necrosis. These studies highlight the risks of targeting PI4KA as an anti-hepatitis C virus strategy and also point to important distinctions between genetic and pharmacological studies when selecting host factors as putative therapeutic targets.

Long-term trial of protection provided by adenovirus-vectored vaccine expressing the PPRV H protein.

A recombinant, replication-defective, adenovirus-vectored vaccine expressing the H surface glycoprotein of peste des petits ruminants virus (PPRV) has previously been shown to protect goats from challenge with wild-type PPRV at up to 4 months post vaccination. Here, we present the results of a longer-term trial of the protection provided by such a vaccine, challenging animals at 6, 9, 12 and 15 months post vaccination. Vaccinated animals developed high levels of anti-PPRV H protein antibodies, which were virus-neutralising, and the level of these antibodies was maintained for the duration of the trial. The vaccinated animals were largely protected against overt clinical disease from the challenge virus. Although viral genome was intermittently detected in blood samples, nasal and/or ocular swabs of vaccinated goats post challenge, viral RNA levels were significantly lower compared to unvaccinated control animals and vaccinated goats did not appear to excrete live virus. This protection, like the antibody response, was maintained at the same level for at least 15 months after vaccination. In addition, we showed that animals that have been vaccinated with the adenovirus-based vaccine can be revaccinated with the same vaccine after 12 months and showed an increased anti-PPRV antibody response after this boost vaccination. Such vaccines, which provide a DIVA capability, would therefore be suitable for use when the current live attenuated PPRV vaccines are withdrawn at the end of the ongoing global PPR eradication campaign.

The hydroxycarboxylic acid receptor HCA2 is required for the protective effect of ketogenic diet in epilepsy.

One third of epilepsy patients are resistant to treatment with current anti-seizure medications. The ketogenic diet is used to treat some forms of refractory epilepsy, but the mechanism of its action has not yet been elucidated. In this study, we aimed to investigate whether the hydroxycarboxylic acid receptor 2 (HCA2), a known immunomodulatory receptor, plays a role in mediating the protective effect of this diet. We demonstrate for the first time that selective agonists at this receptor can directly reduce seizures in animal models. Agonists also reduce network activity in rodent and human brain slices. Ketogenic diet is known to increase circulating levels of endogenous HCA2 agonists, and we show that the effect of ketogenic diet in reducing seizures in the 6 Hz seizure model is negated in HCA2-deficient mice. Our data support the potential of HCA2 as a target for the treatment of epilepsy and potentially for neurodegenerative diseases.

An interview with Steve Wilson. Interview by Kathryn Senior.

Stephen Wilson is Professor of Developmental Genetics at University College, London, UK. He was recently awarded the Remedios Caro Almela Prize for Research in Developmental Neurobiology. We interviewed Steve to find out about how he started on the road to developmental biology research, how he got interested in the brain, his achievements and future challenges.

Fenestrated endovascular aortic repair grafts.

Endovascular repair of AAAs has been embraced by the vascular surgery community. Fenestrated endovascular repair of AAAs is the logical next step to repairing those aneurysms whose anatomy does not provide a secure landing area for the graft below the renal and other visceral vessels. While the early morbidity and mortality reported with endovascular repair is less than with open procedures, additional monitoring and endovascular interventions are necessary with EVAR. Those same issues are presumed to persist with interventions utilizing f-EVAR, along with the additional concern for end-organ ischemia. In addition to fenestrated grafts, grafts with scallop, "chimney," and side branch configurations are being developed. PAs need to keep abreast of developments and understand the benefits and concerns associated with these applications in order to guide and monitor patients whose conditions are suitable for these emerging interventions.

Evaluation of a novel liquid stabilised peste des petits ruminants vaccine: Safety and immunogenic efficacy in sheep and goats in the field in Jordan.

A novel liquid stabiliser was tested with the Nigeria 75/1 Peste des Petit Ruminants (PPR) vaccine over two field studies carried out in sheep and goats. PPR seronegative sheep and goats were selected from farms surrounding Amman, Jordan and were vaccinated with either a stabilised liquid PPR vaccine that had been formulated 3 months prior to use and stored at 2-8 °C or a reconstituted lyophilised PPRV vaccine reconstituted on the day of vaccination. Sera were taken immediately before vaccination and at approximately 1.5, 3 and 6 months following vaccination, then subsequently tested using IDVet ID Screen® PPR competition ELISA and Serum Neutralisation tests to determine the presence of PPRV anti-N antibodies and neutralising antibodies, respectively. It was observed that the liquid-stabilised vaccine was able to provide comparable antibody responses in both species to those induced by the lyophilized vaccine. The ability to store liquid stabilised PPRV vaccine for field use would positively impact PPRV eradication efforts.

Long-term revision rate due to infection in hydrophilic-coated inflatable penile prostheses: 11-year follow-up.

INTRODUCTION: Penile implant surgery continues to be an important option for men with erectile dysfunction. Advancements in technology of implants have contributed to improved survival from mechanical breakdown. Prosthesis infection remains a serious adverse event. For the last 8 years, the Titan implant (Coloplast Corporation, Minneapolis, MN, USA) has been available with an infection-retardant polyvinylpyrrolidone coating. AIM: To compare the infection rates between coated three-piece inflatable penile prostheses (IPPs) with the previous non-coated model. MAIN OUTCOME MEASURES: Infection-related revisions reported in the physician-generated, manufacturer-tabulated patient information forms (PIFs). METHODS: PIFs reported into the voluntary, post-market registry of Coloplast Corporation from July 14, 2000 to September 30, 2011 were retrospectively reviewed. Infection-related revisions entered into the product evaluation database for coated and non-coated IPPs were compared. Data were analyzed using Pearson's chi-squared test. RESULTS: The database included 36,391 PIFs related to primary IPP implantation. At 11 years of follow-up, 4.6% (7,031) of non-coated IPPs were removed or replaced due to infections, whereas 1.4% (29,360) of hydrophilic-coated implants reported replacements due to device infections. The hydrophilic coating of the IPP components makes the device slippery and prevents bacterial attachment. The hydrophilic coating allows rapid absorption of antibiotics in an aqueous solution and allows these water-soluble antibiotics to elute off the device into the implant spaces. Unfortunately, information pertaining to what agents were used in the studies patients was not tabulated. The rate of revision due to device infection was reduced 69.56% in patients with hydrophilic-coated IPPs (P<0.001). CONCLUSION: To the best of our knowledge, this is the longest post-marketing registry report related to IPP infections. At 8 years of follow-up, the hydrophilic-coated IPPs demonstrated a significant reduction in revision rates due to infection when compared with the 11-year follow-up of non-coated implants. Since there was no information or uniformity of antibiotics used in the soaking solution, it is uncertain which antibiotic selection provided the best results. In vitro testing against known infectious agents may further benefit IPP patients by reducing the prosthesis infection rate.

Results of a pilot program to improve phosphorus outcomes in hemodialysis patients.

OBJECTIVE: End-stage renal disease causes dysregulation of bone and mineral metabolism, including increased serum phosphorus levels. Kidney Foundation Kidney Disease Outcome Quality Initiative 2003 guidelines recommend maintaining phosphorus levels between 3.5 and 5.5 mg/dL in dialysis patients. We examined the effects of a focused phosphorus management pilot program designed to improve the percentage of hemodialysis patients achieving phosphorus levels <5.5 mg/dL. DESIGN, SETTING, SUBJECTS, AND INTERVENTION: We conducted a prospective, multicenter, single-arm study at 8 geographically diverse at-risk facilities (n = 702 hemodialysis patients) in a large U.S. dialysis organization. The focused phosphorus management program provided in-service training to staff members, and provided patients with diet and phosphorus management through in-center, 1:1 education and support, direct-to-patient adherence communications, benefit management assistance, and adherence support specific to lanthanum carbonate over a 6-month period. MAIN OUTCOME MEASURE: Facility-level markers of bone and mineral metabolism (phosphorus, parathyroid hormone, corrected calcium) and nutritional status (serum albumin, normalized protein catabolic rate) were assessed before and after program implementation. RESULTS: There was a significant increase in the percentage of patients per facility achieving phosphorus levels <5.5 mg/dL (mean ± SD at baseline = 61.6% ± 5.2%; month 6 = 71.3% ± 9.0%; P < .01) and parathyroid hormone (150 to 300 pg/mL; mean ± SD at baseline = 39.1% ± 2.4%; month 6 = 44.5% ± 7.0%; P = .04). During the course of the evaluation, mean calcium, albumin, and normalized protein catabolic rate levels did not change significantly. CONCLUSIONS: These results show proof-of-concept that a focused phosphorus management program targeting both staff members and patients can significantly improve patient outcomes without compromising nutritional status.

Analysis of exit site care on IV antibiotic use in facilities using electrolytically produced sodium hypochlorite: a pilot retrospective study.

In a retrospective survey of 226 dialysis facilities, the present study compared the effectiveness of topical disinfection with electrolytically produced sodium hypochlorite (ESH) and povidone iodine in preventing central venous catheter-related infections by tracking intravenous (IV) antibiotic administration. In patients undergoing hemodialysis, 18.1% of patients in ESH facilities and 19.2% of patients in povidone iodine facilities were administered IV antibiotics one or more times during the six-month study (p = 0.09). These findings suggest that ESH and povidone iodine are comparable in effectiveness for exit site care in patients dialyzing with central venous catheters.

International consensus conference recommendations on ultrasound education for undergraduate medical students.

OBJECTIVES: The purpose of this study is to provide expert consensus recommendations to establish a global ultrasound curriculum for undergraduate medical students. METHODS: 64 multi-disciplinary ultrasound experts from 16 countries, 50 multi-disciplinary ultrasound consultants, and 21 medical students and residents contributed to these recommendations. A modified Delphi consensus method was used that included a systematic literature search, evaluation of the quality of literature by the GRADE system, and the RAND appropriateness method for panel judgment and consensus decisions. The process included four in-person international discussion sessions and two rounds of online voting. RESULTS: A total of 332 consensus conference statements in four curricular domains were considered: (1) curricular scope (4 statements), (2) curricular rationale (10 statements), (3) curricular characteristics (14 statements), and (4) curricular content (304 statements). Of these 332 statements, 145 were recommended, 126 were strongly recommended, and 61 were not recommended. Important aspects of an undergraduate ultrasound curriculum identified include curricular integration across the basic and clinical sciences and a competency and entrustable professional activity-based model. The curriculum should form the foundation of a life-long continuum of ultrasound education that prepares students for advanced training and patient care. In addition, the curriculum should complement and support the medical school curriculum as a whole with enhanced understanding of anatomy, physiology, pathophysiological processes and clinical practice without displacing other important undergraduate learning. The content of the curriculum should be appropriate for the medical student level of training, evidence and expert opinion based, and include ongoing collaborative research and development to ensure optimum educational value and patient care. CONCLUSIONS: The international consensus conference has provided the first comprehensive document of recommendations for a basic ultrasound curriculum. The document reflects the opinion of a diverse and representative group of international expert ultrasound practitioners, educators, and learners. These recommendations can standardize undergraduate medical student ultrasound education while serving as a basis for additional research in medical education and the application of ultrasound in clinical practice.

Sirt1 overexpression in neurons promotes neurite outgrowth and cell survival through inhibition of the mTOR signaling.

The mammalian nicotinamide-adenine dinucleotide (NAD)-dependent deacetylase Sirt1 impacts different processes involved in the maintenance of brain integrity and in the pathogenic pathways associated with several neurodegenerative disorders, including Alzheimer's disease. Here we used human Sirt1 transgenic mice to demonstrate that neuron-specific Sirt1 overexpression promoted neurite outgrowth and improved cell viability under normal and nutrient-limiting conditions in primary culture systems and that Sirt1-overexpressing neurons exhibited higher tolerance to cell death or degeneration induced by amyloid-ß1-42 oligomers. Coincidentally, we found that enhanced Sirt1 expression in neurons downregulated the mammalian target of rapamycin (mTOR) protein levels and its phosphorylation without changes in its mRNA levels, which was accompanied by concomitant inhibition of the mTOR downstream signaling activity as revealed by decreased p70S6 kinase (p70S6K) phosphorylation at Thr389. Consistently with this, using a Sirt1 siRNA transfection approach, we observed that reduction of endogenous mouse Sirt1 led to increased levels of mTOR and phosphorylation of itself and p70S6K as well as impaired cell survival and neurite outgrowth in wild-type mouse primary neurons, corroborating a suppressing effect of mTOR by Sirt1. Correspondingly, the mTOR inhibitor rapamycin markedly improved neuronal cell survival in response to nutrient deprivation and significantly enhanced neurite outgrowth in wild-type mouse neurons. The protective effect of rapamycin was extended to neurons even with Sirt1 siRNA knockdown that displayed developmental abnormalities compared with siRNA control-treated cells. Collectively, our findings suggest that Sirt1 may act to promote growth and survival of neurons in the central nervous system via its negative modulation of mTOR signaling.

Response of Key Metabolites during a UV-A Exposure Time-Series in the Cyanobacterium Chlorogloeopsis fritschii PCC 6912.

Ultraviolet A (UV-A) is the major component of UV radiation reaching the Earth's surface, causing indirect damage to photosynthetic organisms via the production of reactive oxygen species (ROS). In comparison, UV-B causes both direct damage to biomolecules and indirect damage. UV-B is well studied in cyanobacterial research due to their long evolutionary history and adaptation to high levels of UV, with less work on the effects of UV-A. In this study, the response of key metabolites in Chlorogloeopsis fritschii (C. fritschii) during 48 h of photosynthetically active radiation (PAR, 15 µmol·m-2·s-1) supplemented with UV-A (11 µmol·m-2·s-1) was investigated using gas chromatography- mass spectrometry (GC-MS). Results showed an overall significant increase in metabolite levels up to 24 h of UV-A exposure. Compared with previously reported UV-B (PAR + UV-B) and PAR only results, UV-A showed more similarity compared to PAR only exposure as opposed to supplemented UV-B. The amino acids glutamate, phenylalanine and leucine showed differences in levels between UV (both supplemented UV-A and supplemented UV-B) and PAR only (non-supplemented PAR), hinting to their relevance in UV stress response. The fatty acids, palmitic and stearic acid, showed positive log2 fold-change (FC) in supplemented UV-A and PAR only experiments but negative log2 FC in UV-B, indicating the more harmful effect of UV-B on primary metabolism. Less research has been conducted on UV-A exposure and cyanobacteria, a potential environmental stimuli for the optimisation of metabolites for industrial biotechnology. This study will add to the literature and knowledge on UV-A stress response at the metabolite level in cyanobacteria, especially within the less well-known species C. fritschii.

A Potent and Selective Kallikrein-5 Inhibitor Delivers High Pharmacological Activity in Skin from Patients with Netherton Syndrome.

Regulation of proteolytic activity in the skin plays a pivotal role in epidermal homeostasis. This is best exemplified in Netherton syndrome, a severe genetic skin condition caused by loss-of-function mutations in the gene serine protease inhibitor Kazal-type 5 encoding lympho-epithelial Kazal-type-related inhibitor, a serine protease inhibitor that regulates kallikrein (KLK)-related peptidase 5, 7, and 14 activities. KLK5 plays a central role in stratum corneum shedding and inflammatory cell signaling, activates KLK7 and KLK14, and is therefore an optimal therapeutic target. We aimed to identify a potent and selective small-molecule inhibitor of KLK5 amenable to epidermal delivery. GSK951 was identified using a structure-based design strategy and showed a half maximal inhibitory concentration of 250 pM for KLK5 and greater than 100-fold selectivity over KLK7 and KLK14. Cocrystal structure analysis identified the critical catalytic site interactions to a surrogate for KLK5. Topical application of GSK951-containing cream inhibited KLK5 activity in TgKLK5 mouse skin, reduced transepidermal water loss, and decreased proinflammatory cytokine expression. GSK951 achieved high concentrations in healthy human epidermis following topical application in a cream formulation. Finally, KLK5 protease activity was increased in stratum corneum of patients with Netherton syndrome and significantly inhibited by GSK951. These findings unveil a KLK5-specific small-molecule inhibitor with a high therapeutic potential for patients with Netherton syndrome.