Predicting the emergence of drug-resistant HSV-2: new predictions

BACKGROUND: Mathematical models can be used to predict the emergence and transmission of antiviral resistance. Previously it has been predicted that high usage of antivirals (in immunocompetent populations) to treat Herpes Simplex Virus type 2 (HSV-2) would only lead to fairly low levels of antiviral resistance. The HSV-2 predictions were based upon the assumption that drug-resistant strains of HSV-2 would be less infectious than drug-sensitive strains but that the drug-resistant strains would not be impaired in their ability to reactivate. Recent data suggest that some drug-resistant strains of HSV-2 are likely to be impaired in their ability to reactivate. Objectives: (1) To predict the effect of a high usage of antivirals on the prevalence of drug-resistant HSV-2 under the assumption that drug-resistant strains will be less infectious than drug-sensitive strains of HSV-2 and also have an impaired ability to reactivate. (2) To compare predictions with previous published predictions. METHODS: We generated theoretical drug-resistant HSV-2 strains that were attenuated (in comparison with drug-sensitive strains) in both infectivity and ability to reactivate. We then used a transmission model to predict the emergence and transmission of drug-resistant HSV-2 in the immunocompetent population assuming a high usage of antivirals. RESULTS: Our predictions are an order of magnitude lower than previous predictions; we predict that even after 25 years of high antiviral usage only 5 out of 10,000 immunocompetent individuals will be shedding drug-resistant virus. Furthermore, after 25 years, 52 cases of HSV-2 would have been prevented for each prevalent case of drug-resistant HSV-2. CONCLUSIONS: The predicted levels of drug-resistant HSV-2 for the immunocompetent population are so low that it seems unlikely that cases of drug-resistant HSV-2 will be detected

Time-dependent appearance of myofibroblasts in granulation tissue of human skin wounds

Human skin wounds (66) inflicted between 20 h and 7 months prior to biopsy were studied. In order to identify the type of cellular differentiation of the fibroblastic cells in the granulation tissue, alpha-smooth muscle actin and desmin were immunohistochemically localized. The value of any presumed time-dependent appearance and/or disappearance of positively stained cells was tested for the estimation of wound age. In skin specimens with a wound age less than 5 days (n =15) no typical granulation tissue had developed and no alpha-actin-positive myofibroblasts could be detected. The first appearance of positively reacting myofibroblasts was noted in a 5-day-old wound. In 57% of the lesions with a wound age between 5 and 31 days (25 out of 44 cases) typical granulation tissue formation was present and myofibroblasts with positive reaction for alpha-smooth muscle actin could be identified. Numerous positively reacting cells could generally be found in wounds aged between 16 and 31 days, but also in wounds less than 16 days old. In 29% of the cases with a wound age of more than 31 days (2 out of 7 cases) alpha-sma-positive myofibroblasts also occured. Fibroblastic cells positive for desmin could not be seen at all in our series. Our results demonstrate the appearance of alpha-sma-positive myofibroblasts with the initial formation of typical granulation tissue in human skin lesions as early as approximately 5 days after wounding. In contrast to recent experimental results these cells remained detectable in wounds aged more than 2 months in some cases. The immunohistochemical detection of actin-positive cells, therefore, demonstrates whether an unknown skin wound is aged approximately 5 days or more. Even though a time-dependent decrease of myofibroblasts in human granulation tissue after 31 days in human wounds seems probable, the extended presence (up to about 2 months) of these cells allows no further exact age determination of older wounds

Analysis of gene expression from the Wolbachia genome of a filarial nematode supports both metabolic and defensive roles within the symbiosis

The α-proteobacterium Wolbachia is probably the most prevalent, vertically transmitted symbiont on Earth. In contrast with its wide distribution in arthropods, Wolbachia is restricted to one family of animal-parasitic nematodes, the Onchocercidae. This includes filarial pathogens such as Onchocerca volvulus, the cause of human onchocerciasis, or river blindness. The symbiosis between filariae and Wolbachia is obligate, although the basis of this dependency is not fully understood. Previous studies suggested that Wolbachia may provision metabolites (e.g., haem, riboflavin, and nucleotides) and/or contribute to immune defense. Importantly, Wolbachia is restricted to somatic tissues in adult male worms, whereas females also harbor bacteria in the germline. We sought to characterize the nature of the symbiosis between Wolbachia and O. ochengi, a bovine parasite representing the closest relative of O. volvulus. First, we sequenced the complete genome of Wolbachia strain wOo, which revealed an inability to synthesize riboflavin de novo. Using RNA-seq, we also generated endobacterial transcriptomes from male soma and female germline. In the soma, transcripts for membrane transport and respiration were up-regulated, while the gonad exhibited enrichment for DNA replication and translation. The most abundant Wolbachia proteins, as determined by geLC-MS, included ligands for mammalian Toll-like receptors. Enzymes involved in nucleotide synthesis were dominant among metabolism-related proteins, whereas the haem biosynthetic pathway was poorly represented. We conclude that Wolbachia may have a mitochondrion-like function in the soma, generating ATP for its host. Moreover, the abundance of immunogenic proteins in wOo suggests a role in diverting the immune system toward an ineffective antibacterial response

Caenorhabditis elegans BAH-1 Is a DUF23 Protein Expressed in Seam Cells and Required for Microbial Biofilm Binding to the Cuticle

The cuticle of Caenorhabditis elegans, a complex, multi-layered extracellular matrix, is a major interface between the animal and its environment. Biofilms produced by the bacterial genus Yersinia attach to the cuticle of the worm, providing an assay for surface characteristics. A C. elegans gene required for biofilm attachment, bah-1, encodes a protein containing the domain of unknown function DUF23. The DUF23 domain is found in 61 predicted proteins in C. elegans, which can be divided into three distinct phylogenetic clades. bah-1 is expressed in seam cells, which are among the hypodermal cells that synthesize the cuticle, and is regulated by a TGF-β signaling pathway

Whole breast and regional nodal irradiation in prone versus supine position in left sided breast cancer

Background: Prone whole breast irradiation (WBI) leads to reduced heart and lung doses in breast cancer patients receiving adjuvant radiotherapy. In this feasibility trial, we investigated the prone position for whole breast + lymph node irradiation (WB + LNI). Methods: A new support device was developed for optimal target coverage, on which patients are positioned in a position resembling a phase from the crawl swimming technique (prone crawl position). Five left sided breast cancer patients were included and simulated in supine and prone position. For each patient, a treatment plan was made in prone and supine position for WB + LNI to the whole axilla and the unoperated part of the axilla. Patients served as their own controls for comparing dosimetry of target volumes and organs at risk (OAR) in prone versus in supine position. Results: Target volume coverage differed only slightly between prone and supine position. Doses were significantly reduced (P < 0.05) in prone position for ipsilateral lung (Dmean, D2, V5, V10, V20, V30), contralateral lung (Dmean, D2), contralateral breast (Dmean, D2 and for total axillary WB + LNI also V5), thyroid (Dmean, D2, V5, V10, V20, V30), oesophagus (Dmean and for partial axillary WB + LNI also D2 and V5), skin (D2 and for partial axillary WB + LNI V105 and V107). There were no significant differences for heart and humeral head doses. Conclusions: Prone crawl position in WB + LNI allows for good breast and nodal target coverage with better sparing of ipsilateral lung, thyroid, contralateral breast, contralateral lung and oesophagus when compared to supine position. There is no difference in heart and humeral head doses

Yorkshire Lung Screening Trial (YLST): protocol for a randomised controlled trial to evaluate invitation to community-based low-dose CT screening for lung cancer versus usual care in a targeted population at risk

Introduction: Lung cancer is the world’s leading cause of cancer death. Low-dose computed tomography (LDCT) screening reduced lung cancer mortality by 20% in the US National Lung Screening Trial. Here, we present the Yorkshire Lung Screening Trial (YLST), which will address key questions of relevance for screening implementation. / Methods and analysis: Using a single-consent Zelen’s design, ever-smokers aged 55–80 years registered with a general practice in Leeds will be randomised (1:1) to invitation to a telephone-based risk-assessment for a Lung Health Check or to usual care. The anticipated number randomised by household is 62 980 individuals. Responders at high risk will be invited for LDCT scanning for lung cancer on a mobile van in the community. There will be two rounds of screening at an interval of 2 years. Primary objectives are (1) measure participation rates, (2) compare the performance of PLCOM2012 (threshold ≥1.51%), Liverpool Lung Project (V.2) (threshold ≥5%) and US Preventive Services Task Force eligibility criteria for screening population selection and (3) assess lung cancer outcomes in the intervention and usual care arms. Secondary evaluations include health economics, quality of life, smoking rates according to intervention arm, screening programme performance with ancillary biomarker and smoking cessation studies. / Ethics and dissemination: The study has been approved by the Greater Manchester West research ethics committee (18-NW-0012) and the Health Research Authority following review by the Confidentiality Advisory Group. The results will be disseminated through publication in peer-reviewed scientific journals, presentation at conferences and on the YLST website. / Trial registration numbers: ISRCTN42704678 and NCT03750110

A Rapid and Highly Sensitive Method of Non Radioactive Colorimetric In Situ Hybridization for the Detection of mRNA on Tissue Sections

Background: Non Radioactive colorimetric In Situ Hybridization (NoRISH) with hapten labeled probes has been widely used for the study of gene expression in development, homeostasis and disease. However, improvement in the sensitivity of the method is still needed to allow for the analysis of genes expressed at low levels. Methodology/Principal Findings: A stable, non-toxic, zinc-based fixative was tested in NoRISH experiments on sections of mouse embryos using four probes (Lhx6, Lhx7, ncapg and ret) that have different spatial patterns and expression levels. We showed that Z7 can successfully replace paraformaldehyde used so far for tissue fixation in NoRISH; the morphology of the cryosections of Z7-fixed tissues was excellent, and the fixation time required for tissues sized 1 cm was 1 hr instead of 24 hr for paraformaldehyde. The hybridization signal on the sections of the Z7-treated embryos always appeared earlier than that of the PFA-fixed embryos. In addition, a 50–60 % shorter detection time was observed in specimen of Z7-treated embryos, reducing significantly the time required to complete the method. Finally and most importantly, the strength of the hybridization signal on the sections of the Z7-treated embryos always compared favorably to that of the sections of PFAfixed embryos; these data demonstrate a significant improvement of the sensitivity the method that allows for the analysis of mRNAs that are barely or not detected by the standard colorimetric NoRISH method. Conclusions/Significance: Our NoRISH method provides excellent preservation of tissue morphology, is rapid, highl

Potent Tetrahydroquinolone Eliminates Apicomplexan Parasites

Apicomplexan infections cause substantial morbidity and mortality, worldwide. New, improved therapies are needed. Herein, we create a next generation anti-apicomplexan lead compound, JAG21, a tetrahydroquinolone, with increased sp3-character to improve parasite selectivity. Relative to other cytochrome b inhibitors, JAG21 has improved solubility and ADMET properties, without need for pro-drug. JAG21 significantly reduces Toxoplasma gondii tachyzoites and encysted bradyzoites in vitro, and in primary and established chronic murine infections. Moreover, JAG21 treatment leads to 100% survival. Further, JAG21 is efficacious against drug-resistant Plasmodium falciparum in vitro. Causal prophylaxis and radical cure are achieved after P. berghei sporozoite infection with oral administration of a single dose (2.5 mg/kg) or 3 days treatment at reduced dose (0.625 mg/kg/day), eliminating parasitemia, and leading to 100% survival. Enzymatic, binding, and co-crystallography/pharmacophore studies demonstrate selectivity for apicomplexan relative to mammalian enzymes. JAG21 has significant promise as a pre-clinical candidate for prevention, treatment, and cure of toxoplasmosis and malaria