Augmenter of liver regeneration

‘Augmenter of liver regeneration’ (ALR) (also known as hepatic stimulatory substance or hepatopoietin) was originally found to promote growth of hepatocytes in the regenerating or injured liver. ALR is expressed ubiquitously in all organs, and exclusively in hepatocytes in the liver. ALR, a survival factor for hepatocytes, exhibits significant homology with ERV1 (essential for respiration and viability) protein that is essential for the survival of the yeast, Saccharomyces cerevisiae. ALR comprises 198 to 205 amino acids (approximately 22 kDa), but is post-translationally modified to three high molecular weight species (approximately 38 to 42 kDa) found in hepatocytes. ALR is present in mitochondria, cytosol, endoplasmic reticulum, and nucleus. Mitochondrial ALR may be involved in oxidative phosphorylation, but also functions as sulfhydryl oxidase and cytochrome c reductase, and causes Fe/S maturation of proteins. ALR, secreted by hepatocytes, stimulates synthesis of TNF-α, IL-6, and nitric oxide in Kupffer cells via a G-protein coupled receptor. While the 22 kDa rat recombinant ALR does not stimulate DNA synthesis in hepatocytes, the short form (15 kDa) of human recombinant ALR was reported to be equipotent as or even stronger than TGF-α or HGF as a mitogen for hepatocytes. Altered serum ALR levels in certain pathological conditions suggest that it may be a diagnostic marker for liver injury/disease. Although ALR appears to have multiple functions, the knowledge of its role in various organs, including the liver, is extremely inadequate, and it is not known whether different ALR species have distinct functions. Future research should provide better understanding of the expression and functions of this enigmatic molecule

Regional atmospheric cooling and wetting effect of permafrost thaw-induced boreal forest loss

In the sporadic permafrost zone of North America, thaw‐induced boreal forest loss is leading to permafrost‐free wetland expansion. These land cover changes alter landscape‐scale surface properties with potentially large, however, still unknown impacts on regional climates. In this study, we combine nested eddy covariance flux tower measurements with satellite remote sensing to characterize the impacts of boreal forest loss on albedo, eco‐physiological and aerodynamic surface properties, and turbulent energy fluxes of a lowland boreal forest region in the Northwest Territories, Canada. Planetary boundary layer modelling is used to estimate the potential forest loss impact on regional air temperature and atmospheric moisture. We show that thaw‐induced conversion of forests to wetlands increases albedo: and bulk surface conductance for water vapour and decreases aerodynamic surface temperature. At the same time, heat transfer efficiency is reduced. These shifts in land surface properties increase latent at the expense of sensible heat fluxes, thus, drastically reducing Bowen ratios. Due to the lower albedo of forests and their masking effect of highly reflective snow, available energy is lower in wetlands, especially in late winter. Modelling results demonstrate that a conversion of a present‐day boreal forest–wetland to a hypothetical homogeneous wetland landscape could induce a near‐surface cooling effect on regional air temperatures of up to 3–4 °C in late winter and 1–2 °C in summer. An atmospheric wetting effect in summer is indicated by a maximum increase in water vapour mixing ratios of 2 mmol mol−1. At the same time, maximum boundary layer heights are reduced by about a third of the original height. In fall, simulated air temperature and atmospheric moisture between the two scenarios do not differ. Therefore, permafrost thaw‐induced boreal forest loss may modify regional precipitation patterns and slow down regional warming trends

Effectiveness of vasectomy using cautery

BACKGROUND: Little evidence supports the use of any one vas occlusion method. Data from a number of studies now suggest that there are differences in effectiveness among different occlusion methods. The main objectives of this study were to estimate the effectiveness of vasectomy by cautery and to describe the trends in sperm counts after cautery vasectomy. Other objectives were to estimate time and number of ejaculations to success and to determine the predictive value of success at 12 weeks for final status at 24 weeks. METHODS: A prospective, non-comparative observational study was conducted between November 2001 and June 2002 at 4 centers in Brazil, Canada, the UK, and the US. Four hundred men who chose vasectomy were enrolled and followed for 6 months. Sites used their usual cautery vasectomy technique. Earlier and more frequent than normal semen analyses (2, 5, 8, 12, 16, 20, and 24 weeks after vasectomy) were performed. Planned outcomes included effectiveness (early failure based on semen analysis), trends in sperm counts, time and number of ejaculations to success, predictive value of success at 12 weeks for the outcome at 24 weeks, and safety evaluation. RESULTS: A total of 364 (91%) participants completed follow-up. The overall failure rate based on semen analysis was 0.8% (95% confidence interval 0.2, 2.3). By 12 weeks 96.4% of participants showed azoospermia or severe oligozoospermia (< 100,000 sperm/mL). The predictive value of a single severely oligozoospermia sample at 12 weeks for vasectomy success at the end of the study was 99.7%. One serious unrelated adverse event and no pregnancies were reported. CONCLUSION: Cautery is a very effective method for occluding the vas. Failure based on semen analysis is rare. In settings where semen analysis is not practical, using 12 weeks as a guideline for when men can rely on their vasectomy should lessen the risk of failure compared to using a guideline of 20 ejaculations after vasectomy

A comparison of vas occlusion techniques: cautery more effective than ligation and excision with fascial interposition

BACKGROUND: Vasectomy techniques have been the subject of relatively few rigorous studies. The objective of this analysis was to compare the effectiveness of two techniques for vas occlusion: intraluminal cautery versus ligation and excision with fascial interposition. More specifically, we aimed to compare early failure rates, sperm concentrations, and time to success between the two techniques. METHODS: We compared semen analysis data from men following vasectomy using two occlusion techniques. Data on intraluminal cautery came from a prospective observational study conducted at four sites. Data on ligation and excision with fascial interposition came from a multicenter randomized controlled trial that evaluated the efficacy of ligation and excision with versus without fascial interposition. The surgical techniques used in the fascial interposition study were standardized. The surgeons in the cautery study used their customary techniques, which varied among sites in terms of type of cautery, use of fascial interposition, excision of a short segment of the vas, and use of an open-ended technique. Men in both studies had semen analyses two weeks after vasectomy and then approximately every four weeks. The two outcome measures for the analyses presented here are (a) time to success, defined as severe oligozoospermia, or <100,000 sperm/mL in two consecutive semen analyses; and (b) early vasectomy failure, defined as >10 million sperm/mL at week 12 or later. RESULTS: Vasectomy with cautery was associated with a significantly more rapid progression to severe oligozoospermia and with significantly fewer early failures (1% versus 5%). CONCLUSION: The use of cautery improves vasectomy outcomes. Limitations of this comparison include (a) the variety of surgical techniques in the cautery study and differences in methods of fascial interposition between the two studies, (b) the uncertain correlation between sperm concentrations after vasectomy and the risk of pregnancy, and (c) the use of historical controls and different study sites

Comparison of antihypertensive drug classes for dementia prevention

Background: There is evidence that hypertension in midlife can increase the risk of Alzheimer’s disease and vascular dementia in late life. In addition, some antihypertensive drugs have been proposed to have cognitive benefits, independent of their effect on hypertension. Consequently, there is potential to repurpose antihypertensive drugs for the prevention of dementia. This study systematically compared seven antihypertensive drug classes for this purpose, using the Clinical Practice Research Datalink. Methods: Treatments for hypertension were assessed in an instrumental variable (IV) analysis to address potential confounding and reverse causation. Physicians’ prescribing preference was used as an ordinal instrument, defined by the physicians’ last seven prescriptions. Participants were new antihypertensive users between 1996-2016, aged 40 and over.Results: We analysed 849,378 patients with total follow up of 5,497,266 patient-years. Beta-adrenoceptor blockers and vasodilator antihypertensives were found to confer small protective effects – for example, beta-adrenoceptor blockers resulted in 13 (95% CI: 6 to 20) fewer cases of any dementia per 1000 treated compared with other antihypertensives.Conclusions: We found small differences in antihypertensive drug class effects on risk of dementia outcomes. However, we show the magnitude of the differences between drug classes is smaller than previously reported. Future research should look to implement other causal analysis methods to address biases in conventional observational research with the ultimate aim of triangulating the evidence concerning this hypothesis

Fluorescence hyperspectral imaging (fHSI) using a spectrally resolved detector array

The ability to resolve multiple fluorescent emissions from different biological targets in video rate applications, such as endoscopy and intraoperative imaging, has traditionally been limited by the use of filter-based imaging systems. Hyperspectral imaging (HSI) facilitates the detection of both spatial and spectral information in a single data acquisition, however, instrumentation for HSI is typically complex, bulky and expensive. We sought to overcome these limitations using a novel robust and low cost HSI camera based on a spectrally resolved detector array (SRDA). We integrated this HSI camera into a wide-field reflectance-based imaging system operating in the near-infrared range to assess the suitability for $\textit{in vivo}$ imaging of exogenous fluorescent contrast agents. Using this fluorescence HSI (fHSI) system, we were able to accurately resolve the presence and concentration of at least 7 fluorescent dyes in solution. We also demonstrate high spectral unmixing precision, signal linearity with dye concentration and at depth in tissue mimicking phantoms, and delineate 4 fluorescent dyes $\textit{in vivo}$. Our approach, including statistical background removal, could be directly generalised to broader spectral ranges, for example, to resolve tissue reflectance or autofluorescence and in future be tailored to video rate applications requiring snapshot HSI data acquisition.This work was funded by CRUK (C47594/A16267, C14303/A17197), the EPSRC-CRUK Cancer Imaging Centre in Cambridge and Manchester (grant no. C197/A16465) and the EU FP7 agreement FP7-PEOPLE-2013-CIG-630729. Additional funds were provided by the University of Cambridge MRC Confidence in Concept Award

Vasectomy by ligation and excision, with or without fascial interposition: a randomized controlled trial [ISRCTN77781689]

BACKGROUND: Randomized controlled trials comparing different vasectomy occlusion techniques are lacking. Thus, this multicenter randomized trial was conducted to compare the probability of the success of ligation and excision vasectomy with, versus without, fascial interposition (i.e. placing a layer of the vas sheath between two cut ends of the vas). METHODS: The trial was conducted between December 1999 and June 2002 with a single planned interim analysis. Men requesting vasectomies at eight outpatient clinics in seven countries in North America, Latin America, and Asia were included in the study. The men were randomized to receive vasectomy with versus without fascial interposition. All surgeons performed the vasectomies using the no-scalpel approach to the vas. Participants had a semen analysis two weeks after vasectomy and then every four weeks up to 34 weeks. The primary outcome measure was time to azoospermia. Additional outcome measures were time to severe oligozoospermia (<100 000 sperm/mL) and vasectomy failure based on semen analyses. RESULTS: We halted recruitment after the planned interim analysis, when 841 men had been enrolled. Fascial interposition decreased time to azoospermia (hazard ratio [HR], 1.35; P < 0.0001) and time to severe oligozoospermia (HR, 1.32; P < 0.0001) and reduced failures based on semen analysis by about half, from 12.7% (95% confidence interval [CI], 9.7 to 16.3) to 5.9% (95% CI, 3.8 to 8.6) (P < 0.0001). Older men benefited less from fascial interposition than younger men in terms of the speed of achieving azoospermia. However, the number of vasectomy failures was reduced to a similar degree in all age groups. Slightly more adverse events occurred in the fascial interposition group, but the difference was not significant. These failure rates may appear high to practitioners in countries such as the USA, but they are similar to results from other careful studies of ligation and excision techniques. CONCLUSION: Fascial interposition significantly improves vasectomy success when ligation and excision is the method of vas occlusion. A limitation of this study is that the correlation between postvasectomy sperm concentrations and risk of pregnancy is not well quantified

Genome-wide diversity and phylogeography of Mycobacterium avium subsp. paratuberculosis in Canadian dairy cattle

Mycobacterium avium subsp. paratuberculosis (MAP) is the causative bacterium of Johne’s disease (JD) in ruminants. The control of JD in the dairy industry is challenging, but can be improved with a better understanding of the diversity and distribution of MAP subtypes. Previously established molecular typing techniques used to differentiate MAP have not been sufficiently discriminatory and/or reliable to accurately assess the population structure. In this study, the genetic diversity of 182 MAP isolates representing all Canadian provinces was compared to the known global diversity, using single nucleotide polymorphisms identified through whole genome sequencing. MAP isolates from Canada represented a subset of the known global diversity, as there were global isolates intermingled with Canadian isolates, as well as multiple global subtypes that were not found in Canada. One Type III and six “Bison type” isolates were found in Canada as well as one Type II subtype that represented 86% of all Canadian isolates. Rarefaction estimated larger subtype richness in Québec than in other Canadian provinces using a strict definition of MAP subtypes and lower subtype richness in the Atlantic region using a relaxed definition. Significant phylogeographic clustering was observed at the inter-provincial but not at the intra-provincial level, although most major clades were found in all provinces. The large number of shared subtypes among provinces suggests that cattle movement is a major driver of MAP transmission at the herd level, which is further supported by the lack of spatial clustering on an intra-provincial scale

Transcriptome profiling of rabbit parthenogenetic blastocysts developed under in vivo conditions

Parthenogenetic embryos are one attractive alternative as a source of embryonic stem cells, although many aspects related to the biology of parthenogenetic embryos and parthenogenetically derived cell lines still need to be elucidated. The present work was conducted to investigate the gene expression profile of rabbit parthenote embryos cultured under in vivo conditions using microarray analysis. Transcriptomic profiles indicate 2541 differentially expressed genes between parthenotes and normal in vivo fertilised blastocysts, of which 76 genes were upregulated and 16 genes downregulated in in vivo cultured parthenote blastocyst, using 3 fold-changes as a cut-off. While differentially upregulated expressed genes are related to transport and protein metabolic process, downregulated expressed genes are related to DNA and RNA binding. Using microarray data, 6 imprinted genes were identified as conserved among rabbits, humans and mice: GRB10, ATP10A, ZNF215, NDN, IMPACT and SFMBT2. We also found that 26 putative genes have at least one member of that gene family imprinted in other species. These data strengthen the view that a large fraction of genes is differentially expressed between parthenogenetic and normal embryos cultured under the same conditions and offer a new approach to the identification of imprinted genes in rabbit. © 2012 Naturil-Alfonso et al.This work was supported by Generalitat Valenciana research programme (Prometeo 2009/125). Carmen Naturil was supported by Generalitat Valenciana research programme (Prometeo 2009/125). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Naturil Alfonso, C.; Saenz De Juano Ribes, MDLD.; Peñaranda, D.; Vicente Antón, JS.; Marco Jiménez, F. (2012). Transcriptome profiling of rabbit parthenogenetic blastocysts developed under in vivo conditions. PLoS ONE. 7(12):1-11. https://doi.org/10.1371/journal.pone.0051271S111712Harness, J. 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Proceedings of the National Academy of Sciences, 100(Supplement 1), 11911-11916. doi:10.1073/pnas.2034195100Chen, Z., Liu, Z., Huang, J., Amano, T., Li, C., Cao, S., … Liu, L. (2009). Birth of Parthenote Mice Directly from Parthenogenetic Embryonic Stem Cells. Stem Cells, 27(9), 2136-2145. doi:10.1002/stem.158Sritanaudomchai, H., Ma, H., Clepper, L., Gokhale, S., Bogan, R., Hennebold, J., … Mitalipov, S. (2010). Discovery of a novel imprinted gene by transcriptional analysis of parthenogenetic embryonic stem cells. Human Reproduction, 25(8), 1927-1941. doi:10.1093/humrep/deq144Fang, Z. F., Gai, H., Huang, Y. Z., Li, S. G., Chen, X. J., Shi, J. J., … Sheng, H. Z. (2006). Rabbit embryonic stem cell lines derived from fertilized, parthenogenetic or somatic cell nuclear transfer embryos. Experimental Cell Research, 312(18), 3669-3682. doi:10.1016/j.yexcr.2006.08.013Wang, S., Tang, X., Niu, Y., Chen, H., Li, B., Li, T., … Ji, W. (2007). 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General and Comparative Endocrinology, 142(1-2), 134-142. doi:10.1016/j.ygcen.2004.12.019Llobat, L., Marco-Jiménez, F., Peñaranda, D., Saenz-de-Juano, M., & Vicente, J. (2011). Effect of Embryonic Genotype on Reference Gene Selection for RT-qPCR Normalization. Reproduction in Domestic Animals, 47(4), 629-634. doi:10.1111/j.1439-0531.2011.01934.xLiu, N., Enkemann, S. A., Liang, P., Hersmus, R., Zanazzi, C., Huang, J., … Liu, L. (2010). Genome-wide Gene Expression Profiling Reveals Aberrant MAPK and Wnt Signaling Pathways Associated with Early Parthenogenesis. Journal of Molecular Cell Biology, 2(6), 333-344. doi:10.1093/jmcb/mjq029Abdoon, A. S., Ghanem, N., Kandil, O. M., Gad, A., Schellander, K., & Tesfaye, D. (2012). cDNA microarray analysis of gene expression in parthenotes and in vitro produced buffalo embryos. Theriogenology, 77(6), 1240-1251. doi:10.1016/j.theriogenology.2011.11.004Labrecque, R., & Sirard, M.-A. (2011). Gene expression analysis of bovine blastocysts produced by parthenogenic activation or fertilisation. Reproduction, Fertility and Development, 23(4), 591. doi:10.1071/rd10243Rizos, D., Clemente, M., Bermejo-Alvarez, P., de La Fuente, J., Lonergan, P., & Gutiérrez-Adán, A. (2008). Consequences ofIn VitroCulture Conditions on Embryo Development and Quality. Reproduction in Domestic Animals, 43, 44-50. doi:10.1111/j.1439-0531.2008.01230.xLonergan, P., Rizos, D., Kanka, J., Nemcova, L., Mbaye, A., Kingston, M., … Boland, M. (2003). Temporal sensitivity of bovine embryos to culture environment after fertilization and the implications for blastocyst quality. Reproduction, 337-346. doi:10.1530/rep.0.1260337Memili, E., & First, N. L. (2000). Zygotic and embryonic gene expression in cow: a review of timing and mechanisms of early gene expression as compared with other species. Zygote, 8(1), 87-96. doi:10.1017/s0967199400000861Latham, K. E. (2001). Embryonic genome activation. 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Biology of Reproduction, 81(5), 906-920. doi:10.1095/biolreprod.109.078139Cruz-Correa, M., Zhao, R., Oveido, M., Bernabe, R. D., Lacourt, M., Cardona, A., … Giardiello, F. M. (2009). Temporal stability and age-related prevalence of loss of imprinting of the insulin-like growth factor-2 gene. Epigenetics, 4(2), 114-118. doi:10.4161/epi.4.2.7954Park, C.-H., Uh, K.-J., Mulligan, B. P., Jeung, E.-B., Hyun, S.-H., Shin, T., … Lee, C.-K. (2011). Analysis of Imprinted Gene Expression in Normal Fertilized and Uniparental Preimplantation Porcine Embryos. PLoS ONE, 6(7), e22216. doi:10.1371/journal.pone.0022216Thurston, A., Taylor, J., Gardner, J., Sinclair, K. D., & Young, L. E. (2007). Monoallelic expression of nine imprinted genes in the sheep embryo occurs after the blastocyst stage. Reproduction, 135(1), 29-40. doi:10.1530/rep-07-0211Li, Y., & Sasaki, H. (2011). Genomic imprinting in mammals: its life cycle, molecular mechanisms and reprogramming. Cell Research, 21(3), 466-473. doi:10.1038/cr.2011.15Mamo, S., Gal, A., Polgar, Z., & Dinnyes, A. (2008). Expression profiles of the pluripotency marker gene POU5F1 and validation of reference genes in rabbit oocytes and preimplantation stage embryos. BMC Molecular Biology, 9(1), 67. doi:10.1186/1471-2199-9-67Navarrete Santos, A., Tonack, S., Kirstein, M., Pantaleon, M., Kaye, P., & Fischer, B. (2004). Insulin acts via mitogen-activated protein kinase phosphorylation in rabbit blastocysts. Reproduction, 128(5), 517-526. doi:10.1530/rep.1.0020