Serological Evidence and Risk Factors for Swine Influenza Infections among Chinese Swine Workers in Guangdong Province

During July to September 2014, we performed a controlled, cross-sectional, seroepidemiologic study among 203 swine workers and 115 control subjects in Guangdong Province. Sera were tested using a hemagglutination inhibition assay against locally-isolated swine H3N2 and H1N1 viruses and commercially-obtained human influenza viral antigens. We found swine workers had a greater prevalence and odds of seropositivity against the swine H3N2 virus (17.3% vs. 7.0%; adjusted OR, 3.4; 95% CI, 1.1 -10.7). Younger age, self-report of a respiratory illness during the last 12 months, and seropositivity against seasonal H3N2 virus were identified as significant risk factors for seropositivity against swine H3N2 virus. As swine workers in China may be exposed to novel influenza viruses, it seems prudent for China to conduct special surveillance for such viruses among them. It also seems wise to offer such workers seasonal influenza vaccines with a goal to reduce cross-species influenza virus transmission.     

Assessment of Blood Collection from the Lateral Saphenous Vein for Microfilaria Counts in Mongolian Gerbils (Meriones unguiculatus) Infected with Brugia pahangi

The NIH guidelines for survival bleeding of mice and rats note that using the retroorbital plexus has a greater potential for complications than do other methods of blood collection and that this procedure should be performed on anesthetized animals. Lateral saphenous vein puncture has a low potential for complications and can be performed without anesthesia. Mongolian gerbils (Meriones unguiculatus) are the preferred rodent model for filarial parasite research. To monitor microfilaria counts in the blood, blood sampling from the orbital plexus has been the standard. Our goal was to refine the blood collection technique. To determine whether blood collection from the lateral saphenous vein was a feasible alternative to retroorbital sampling, we compared microfilaria counts in blood samples collected by both methods from 21 gerbils infected with the filarial parasitic worm Brugia pahangi. Lateral saphenous vein counts were equivalent to retroorbital counts at relatively high counts (greater than 50 microfilariae per 20 µL) but were significantly lower than retroorbital counts when microfilarial concentrations were lower. Our results indicate that although retroorbital collection may be preferable when low concentrations of microfilariae need to be enumerated, the lateral saphenous vein is a suitable alternative site for blood sampling to determine microfilaremia and is a feasible refinement that can benefit the wellbeing of gerbils.Abbreviations: FR3, Filariasis Research Reagent Resource CenterLymphatic filariasis a major threat to human health worldwide. More than one billion people in more than 90 countries around the globe are at risk from lymphatic filariasis, and between 120 and 150 million people are infected.^9,11,25 Infection with the filarioid parasitic worms Brugia malayi and Wuchereria bancrofti can result in severe sequelae, including elephantiasis and hydrocoele formation.^3,11,15,25 In addition to the clinical manifestations of filariasis are the potential associated psychologic, social, and cultural effects in persons exhibiting visible signs of infection.^9,23,34The life cycle of filarioid nematodes requires an arthropod intermediate host and a definitive vertebrate host. Within the definitive host, dioecious adult filarial nematodes reproduce sexually. Inseminated adult female worms then release live, sheathed microfilariae into the lymph that circulate in the peripheral blood.²¹ In the case of B. malayi and W. bancrofti, the intermediate host is the mosquito.²¹ When an uninfected mosquito ingests a blood meal from an infected human, ingested microfilariae unsheathe to penetrate the midgut of the mosquito to reach the thoracic muscles and molt twice, to become the infectious third-stage larvae. The third-stage larvae then migrate to the mosquito''s proboscis and can infect another human when the mosquito takes a blood meal.^10,11 The third-stage larvae enter the new host''s lymphatic system which is their final location, where they undergo 2 molts into adults.Because of the complexity of filarioid life cycles, research involving these parasites can be logistically challenging. Although mice can be infected with W. bancrofti, they do not maintain the infection.³⁵ Furthermore, there is no suitable nonhuman host that can maintain a patent infection, with the exception of the silvered leaf monkey (Trachypithecus cristatus).⁹ Because the closely related parasites B. malayi and B. pahangi have more extensive host ranges than does W. bancrofti, they are easier to maintain in a research setting. Domestic cats (Felis catus) can be experimentally infected with B. malayi and develop a patent infection, and both domestic cats and dogs (Canis familiaris) can be experimentally infected with B. pahangi^13,29,37 and are suitable for obtaining microfilaremic blood for experimental feeding of mosquitoes. The Mongolian gerbil can be infected with B. pahangi. Because replacing a phylogenetically higher species with a lower species is preferable³⁶ and because performing experiments involving dogs and cats can be logistically difficult and cost-prohibitive, many researchers prefer a rodent model, specifically gerbils.The Filariasis Research Reagent Resource Center (FR3) is an NIH center whose mandate is to support filariasis research worldwide. The FR3 provides parasitic and molecular resources, as well as training in animal procedures, to researchers from many nations. The FR3 maintains both B. malayi and B. pahangi, and researchers occasionally require gerbils with patent infections. Because the required level of microfilaria counts varies among investigators, an accurate microfilaria count must be obtained prior to the shipment of gerbils. For example, some experiments require that live mosquitoes feed directly on infected gerbils, and when the microfilaria level is too low, the mosquitoes do not become infected. Conversely when the level is too high, the migration of microfilariae and the later larval stages can kill the mosquitoes. Historically, the FR3 has used retroorbital sampling under general anesthesia to obtain the blood for microfilaria counts.²⁸ Although this method has been fairly successful, the FR3 has encountered occasional complications secondary to the procedure, including exophthalmia and, rarely, death under anesthesia. The NIH guidelines for survival bleeding of mice and rats notes that compared with other blood collection methods, retroorbital sampling has a greater potential for complications. The guidelines recommend a 10- to 14-d period between retroorbital blood collections and state that the procedure is “…best conducted under general anesthesia.”³¹ By comparison, collecting blood from the lateral saphenous vein is considered to have a low potential for complications or tissue damage, can be performed without general anesthesia,^12,18,31 and can be performed repeatedly, even daily.³¹In the current study, we proposed to refine the blood collection method being used by FR3 by developing sampling from the lateral saphenous vein as the new standard blood-collection method for monitoring microfilaremia. Our goal was to assess blood collection from the lateral saphenous vein as a feasible refinement technique to potentially replace retroorbital sampling by determining whether the microfilaria counts in blood collected from the lateral saphenous vein without anesthesia were sufficiently similar to those from retroorbital blood sampling with anesthesia to provide adequate information about the microfilaremia level.     

Next generation sequencing demonstrates association between tumor suppressor gene aberrations and poor outcome in patients with cancer

Next generation sequencing is transforming patient care by allowing physicians to customize and match treatment to their patients’ tumor alterations. Our goal was to study the association between key molecular alterations and outcome parameters. We evaluated the characteristics and outcomes (overall survival (OS), time to metastasis/recurrence, and best progression-free survival (PFS)) of 392 patients for whom next generation sequencing (182 or 236 genes) had been performed. The Kaplan-Meier method and Cox regression models were used for our analysis, and results were subjected to internal validation using a resampling method (bootstrap analysis). In a multivariable analysis (Cox regression model), the parameters that were statistically associated with a poorer overall survival were the presence of metastases at diagnosis (P = 0.014), gastrointestinal histology (P < 0.0001), PTEN (P < 0.0001), and CDKN2A alterations (P = 0.0001). The variables associated with a shorter time to metastases/recurrence were gastrointestinal histology (P = 0.004), APC (P = 0.008), PTEN (P = 0.026) and TP53 (P = 0.044) alterations. TP53 (P = 0.003) and PTEN (P = 0.034) alterations were independent predictors of a shorter best PFS. A personalized treatment approach (matching the molecular aberration with a cognate targeted drug) also correlated with a longer best PFS (P = 0.046). Our study demonstrated that, across diverse cancers, anomalies in specific tumor suppressor genes (PTEN, CDKN2A, APC, and/or TP53) were independently associated with a worse outcome, as reflected by time to metastases/recurrence, best PFS on treatment, and/or overall survival. These observations suggest that molecular diagnostic tests may provide important prognostic information in patients with cancer.     

The very low birth weight infant microbiome and childhood health

This review describes current understandings about the nature of the very low birth weight infant (VLBW) gut microbiome. VLBW infants often experience disruptive pregnancies and births, and prenatal factors can influence the maturity of the gut and immune system, and disturb microbial balance and succession. Many VLBWs experience rapid vaginal or Caesarean births. After birth these infants often have delays in enteral feeding, and many receive little or no mother's own milk. Furthermore the stressors of neonatal life in the hospital environment, common use of antibiotics, invasive procedures and maternal separation can contribute to dysbiosis. These infants experience gastrointestinal dysfunction, sepsis, transfusions, necrotizing enterocolitis, oxygen toxicity, and other pathophysiological consditions that affect the normal microbiota. The skin is susceptible to dysbiosis, due to its fragility and contact with NICU organisms. Dysbiosis in early life may resolve but little is known about the timing of the development of the signature gut microbiome in VLBWs. Dysbiosis has been associated with a number of physical and behavioral problems, including autism spectrum disorders, allergy and asthma, gastrointestinal disease, obesity, depression, and anxiety. Dysbiosis may be prevented or ameliorated in part by prenatal care, breast milk feeding, skin to skin contact, use of antibiotics only when necessary, and vigilance during infancy and early childhood. Birth Defects Research (Part C) 105:252–264, 2015. © 2015 Wiley Periodicals, Inc.     

Proteomic signatures of serum albumin-bound proteins from stroke patients with and without endovascular closure of PFO are significantly different and suggest a novel mechanism for cholesterol efflux

Background

The anatomy of PFO suggests that it can allow thrombi and potentially harmful circulatory factors to travel directly from the venous to the arterial circulation – altering circulatory phenotype. Our previous publication using high-resolution LC-MS/MS to profile protein and peptide expression patterns in plasma showed that albumin was relatively increased in donor samples from PFO-related than other types of ischemic strokes. Since albumin binds a host of molecules and acts as a carrier for lipoproteins, small molecules and drugs, we decided to investigate the albumin-bound proteins (in a similar sample cohort) in an effort to unravel biological changes and potentially discover biomarkers related to PFO-related stroke and PFO endovascular closure.

Methods

The method used in this study combined albumin immuno-enrichment with high resolution LC-MS in order to specifically capture and quantify the albumin-bound proteins. Subsequently, we measured cholesterol and HDL in a larger, separate cohort of PFO stroke patients, pre and post closure.

Results

The results demonstrated that a number of proteins were specifically associated with albumin in samples with and without endovascular closure of the PFO, and that the protein profiles were very different. Eight proteins, typically associated with HDL were common to both sample sets and quantitatively differently abundant. Pathway analysis of the MS results suggested that enhanced cholesterol efflux and reduced lipid oxidation were associated with PFO closure. Measurement of total cholesterol and HDL in a larger cohort of PFO closure samples using a colorimetric assay was consistent with the proteomic predictions.

Conclusions

The collective data presented in this study demonstrate that analysis of albumin-bound proteins could provide a valuable tool for biomarker discovery on the effects of PFO endovascular closure. In addition, the results suggest that PFO endovascular closure can potentially have effects on HDL, cholesterol and albumin-bound ApoA-I abundance, therefore possibly providing benefits in cardioprotective functions.

Electronic supplementary material

The online version of this article (doi:10.1186/1559-0275-12-2) contains supplementary material, which is available to authorized users.     

Widespread Recombination,Reassortment, and Transmission of Unbalanced Compound Viral Genotypes in Natural Arenavirus Infections

Arenaviruses are one of the largest families of human hemorrhagic fever viruses and are known to infect both mammals and snakes. Arenaviruses package a large (L) and small (S) genome segment in their virions. For segmented RNA viruses like these, novel genotypes can be generated through mutation, recombination, and reassortment. Although it is believed that an ancient recombination event led to the emergence of a new lineage of mammalian arenaviruses, neither recombination nor reassortment has been definitively documented in natural arenavirus infections. Here, we used metagenomic sequencing to survey the viral diversity present in captive arenavirus-infected snakes. From 48 infected animals, we determined the complete or near complete sequence of 210 genome segments that grouped into 23 L and 11 S genotypes. The majority of snakes were multiply infected, with up to 4 distinct S and 11 distinct L segment genotypes in individual animals. This S/L imbalance was typical: in all cases intrahost L segment genotypes outnumbered S genotypes, and a particular S segment genotype dominated in individual animals and at a population level. We corroborated sequencing results by qRT-PCR and virus isolation, and isolates replicated as ensembles in culture. Numerous instances of recombination and reassortment were detected, including recombinant segments with unusual organizations featuring 2 intergenic regions and superfluous content, which were capable of stable replication and transmission despite their atypical structures. Overall, this represents intrahost diversity of an extent and form that goes well beyond what has been observed for arenaviruses or for viruses in general. This diversity can be plausibly attributed to the captive intermingling of sub-clinically infected wild-caught snakes. Thus, beyond providing a unique opportunity to study arenavirus evolution and adaptation, these findings allow the investigation of unintended anthropogenic impacts on viral ecology, diversity, and disease potential.     

Receptor Polymorphism and Genomic Structure Interact to Shape Bitter Taste Perception

The ability to taste bitterness evolved to safeguard most animals, including humans, against potentially toxic substances, thereby leading to food rejection. Nonetheless, bitter perception is subject to individual variations due to the presence of genetic functional polymorphisms in bitter taste receptor (TAS2R) genes, such as the long-known association between genetic polymorphisms in TAS2R38 and bitter taste perception of phenylthiocarbamide. Yet, due to overlaps in specificities across receptors, such associations with a single TAS2R locus are uncommon. Therefore, to investigate more complex associations, we examined taste responses to six structurally diverse compounds (absinthin, amarogentin, cascarillin, grosheimin, quassin, and quinine) in a sample of the Caucasian population. By sequencing all bitter receptor loci, inferring long-range haplotypes, mapping their effects on phenotype variation, and characterizing functionally causal allelic variants, we deciphered at the molecular level how a subjects’ genotype for the whole-family of TAS2R genes shapes variation in bitter taste perception. Within each haplotype block implicated in phenotypic variation, we provided evidence for at least one locus harboring functional polymorphic alleles, e.g. one locus for sensitivity to amarogentin, one of the most bitter natural compounds known, and two loci for sensitivity to grosheimin, one of the bitter compounds of artichoke. Our analyses revealed also, besides simple associations, complex associations of bitterness sensitivity across TAS2R loci. Indeed, even if several putative loci harbored both high- and low-sensitivity alleles, phenotypic variation depended on linkage between these alleles. When sensitive alleles for bitter compounds were maintained in the same linkage phase, genetically driven perceptual differences were obvious, e.g. for grosheimin. On the contrary, when sensitive alleles were in opposite phase, only weak genotype-phenotype associations were seen, e.g. for absinthin, the bitter principle of the beverage absinth. These findings illustrate the extent to which genetic influences on taste are complex, yet arise from both receptor activation patterns and linkage structure among receptor genes.     

Implications for human adipose‐derived stem cells in plastic surgery

Adipose‐derived stem cells (ADSCs) are a subset of mesenchymal stem cells (MSCs) that possess many of the same regenerative properties as other MSCs. However, the ubiquitous presence of ADSCs and their ease of access in human tissue have led to a burgeoning field of research. The plastic surgeon is uniquely positioned to harness this technology because of the relative frequency in which they perform procedures such as liposuction and autologous fat grafting. This review examines the current landscape of ADSC isolation and identification, summarizes the current applications of ADSCs in the field of plastic surgery, discusses the risks associated with their use, current barriers to universal clinical translatability, and surveys the latest research which may help to overcome these obstacles.