An adventitious agent-free clonal cell line that is highly susceptible to foot -and-mouth disease virus.

Porcine LFBKαVß6 cells have been successfully used for diagnostics and propagation of all FMDV serotypes/subtypes. Unfortunately, after initial characterization, these cells showed contamination with bovine viral diarrhea virus (BVDV), a non-cytopathic adventitious agent. Persistent infection with BVDV could interfere with diagnostic tests and, also prevent consideration for other uses, i.e., vaccine production. In this study, we developed a three-prong methodology to completely remove BVDV from LFBKαVß6 cells. Combined treatment with siRNA against BVDV NS5A, porcine interferon alpha and ribavirin resulted in the elimination of BVDV, as determined by immunohistochemistry analysis, quantitative RT-PCR and RNA sequencing. Importantly, elimination of BVDV from LFBKαVß6 did not affect FMDV growth and plaque phenotype from different serotypes isolated and propagated in the clean cell line, newly named MGPK αVß6-C5. Additionally, isolation of FMDV from field oro-pharyngeal samples, was successful at the same sensitivity as in BVDV-contaminated LFBKαVß6 cells. Our results identified a direct method to efficiently eliminate BVDV from porcine cells without altering FMDV permissiveness, diagnostic value, or potential for use in vaccine production. Furthermore, these cells may provide an improved platform for diagnostics and propagation of other viruses of interest in the veterinary field and the virology community at large.

Comparison of the horizontal diameter to a modeled area of traction in eyes with vitreomacular traction: is the diameter close enough to the truth?

PURPOSE: In daily practice, vitreomacular traction (VMT) is described by the horizontal diameter of its attachment site implying a regular round shape of VMT. We investigated the deviation from this circular area of vitreous traction in patients with VMT. METHODS: A retrospective analysis of optical coherence tomography (OCT) scans was performed. The area of vitreomacular attachment was determined using six radial OCT scans (Ameasured). The assumed circular area of traction was calculated based on measuring the maximal horizontal diameter for comparison (Acircular). RESULTS: Thirty-seven eyes of 37 patients with pure VMT were included. Patients' mean age was 72.8 ± 8.2 years. Mean horizontal VMT diameter was 400.8 ± 230.5 µm (median 361 µm; range 44-991 µm). While there was no difference between mean areas of traction for Acircular and Ameasured (P = 0.93), the individual difference (|Acircular - Ameasured|) was 0.042 (± 0.044) mm2 in mean or relative 73.0% (± 135.8%). A difference of ≥ 30% of Ameasured to Acircular was found in 16 eyes (43.2%) and ≥ 100% in 7 eyes (18.9%), respectively. CONCLUSION: Vitreous attachment sites possess an irregular non-circular shape in a significant number of eyes with VMT. Consequently, the area of traction appears inaccurately described by its horizontal VMT diameter alone. As the area of traction is important for therapeutic recommendation, our results emphasize the need for a more precise description of the area of traction in eyes with VMT.

Renal transplantation in 4 patients with methylmalonic aciduria: a cell therapy for metabolic disease.

INTRODUCTION: Patients with methylmalonic acidemia (MMA) may develop many complications despite medical treatment, in particular, severe central nervous system damage and chronic kidney disease (CKD). A kidney transplant may partially correct the metabolic dysfunctions. Liver, kidney and combined liver-kidney transplantations have been advocated but no guidelines are available to identify the most suitable organ to transplant. PATIENTS AND METHODS: Four patients with MMA (mut° phenotype) received a kidney graft because of repeated metabolic decompensations, with progression to CKD in 3 patients (end-stage kidney disease in two patients and CKD stage III in one patient with an estimated glomerular filtration rate [eGFR] of 40ml/min/1.73m(2)) but normal renal function in one (eGFR of 93ml/min/1.73m(2)) before transplantation. RESULTS: The medium age at transplantation was 7.9y (5-10.2) and the median follow-up was 2.8years (1.8-4.6). Renal transplantation improved the relevant metabolic parameters in 4/4 patients and renal function in the patients with CKD. Plasma and urinary MMA levels immediately decreased and remained normal or subnormal (mean values of plasma MMA before transplantation 1530µmol/L versus 240µmol/L after transplantation, and mean values of urine MMA before transplantation 4700mmol/mol creatinine versus 2300mmol/mol creatinine after transplantation). No further acute metabolic decompensation was observed and protein-intake was increased from 0.60 to 0.83g/Kg/day. One patient transplanted at age 9.7years developed a hepatoblastoma at age 11years with subsequent neurological complications and eventually died. The three other patients are alive. Two of them remained neurologically stable. The 3rd patient who displayed choreoathetosis transiently improved his neurological condition immediately after transplantation and then remained stable. CONCLUSION: Kidney transplantation represents an interesting alternative therapeutic option in methylmalonic aciduria, for renal complications but also as a "cellular therapy" that may significantly reduce metabolic decompensations and hospitalizations. However, further neurological impairment remains possible.

Inhibition of B virus (Macacine herpesvirus 1) by conventional and experimental antiviral compounds.

B virus infection of humans results in high morbidity and mortality in as many as 80% of identified cases. The main objective of this study was to conduct a comparative analysis of conventional and experimental antiviral drug susceptibilities of B virus isolates from multiple macaque species and zoonotically infected humans. We used a plaque reduction assay to establish the effective inhibitory doses of acyclovir, ganciclovir, and vidarabine, as well as those of a group of experimental nucleoside analogs with known anti-herpes simplex virus activity. Four of the experimental drugs tested were 10- to 100-fold more potent inhibitors of B virus replication than conventional antiviral agents. Drug efficacies were similar for multiple B virus isolates tested, with variations within 2-fold of the median effective concentration (EC(50)) for each drug, and each EC(50) was considerably lower than those for B virus thymidine kinase (TK) mutants. We observed no differences in the viral TK amino acid sequence between B virus isolates from rhesus monkeys and those from human zoonoses. Differences in the TK protein sequence between cynomolgus and pigtail macaque B virus isolates did not affect drug sensitivity except in the case of one compound. Taken together, these data suggest that future B virus zoonoses will respond consistently to conventional antiviral treatment. Further, the considerably higher potency of FEAU (2'-fluoro-5-ethyl-Ara-U) than of conventional antiviral drugs argues for its compassionate use in advanced human B virus infections.

Postdiarrheal hemolytic and uremic syndrome with severe multiorgan involvement and associated early risk factors.

AIM: Identifying early clinical and biological factors associated with severe forms of postdiarrheal hemolytic uremic syndrome (D+HUS) that may help practitioners determine appropriate treatment. METHODS: This retrospective study was conducted in 49 children with D+HUS between 2001 and 2011. Severe forms were defined as occurrence of one of the following conditions: death, major neurological involvement, cardiovascular involvement, and/or the presence of sequelae (neurological, cardiovascular, pancreatic, or renal). RESULTS: During the acute phase, 35 children exhibited at least one type of extrarenal involvement including 13 severe forms with a median delayed occurrence after admission of 4.5 days (range: 1-8) for comatose children and 5 days (range: 2-6) for cardiovascular involvement; 32 children required dialysis and three died. In multivariate analysis, (i) major neurological involvement (n=13), (ii) dialysis (n=32), and (iii) sequelae (n=12) were associated with (i) fever during the prodromal phase requiring dialysis at admission, (ii) C-reactive protein level (CRP) >22mg/L at admission, and (iii) major neurological involvement and a white blood cell count (WBC)>20×103/mm3 during the acute stage, respectively. CONCLUSIONS: D+HUS is a multiorgan disease with a delayed occurrence of life-threatening extrarenal organ involvement. Severe forms appear to be associated with early biological and clinical inflammatory parameters.

Defense of benthic invertebrates against surface colonization by larvae: a chemical arms race.

Sessile invertebrates evolved in a competitive milieu where space is a limiting resource, setting off an arms race between adults that must maintain clean surfaces and larvae that must locate and attach to a suitable substratum. I review the evidence that invertebrates chemically deter or kill the propagules of fouling animals and protists under natural conditions, and that chemosensory mechanisms may allow larvae to detect and avoid settling on chemically protected organisms. The fouling process is an ecologically complex web of interactions between basibionts, surface-colonizing microbes, and fouling larvae, all mediated by chemical signaling. Host-specific bacterial communities are maintained by many invertebrates, and may inhibit fouling by chemical deterrence of larvae, or by preventing biofilm formation by inductive strains. Larval settlement naturally occurs in a turbulent environment, yet the effects of waterborne versus surface-adsorbed chemical defenses have not been compared in flow, limiting our understanding of how larvae respond to toxic surfaces in the field. The importance of evaluating alternative hypotheses such as mechanical and physical defense is discussed, as is the need for ecologically relevant bioassays that quantify effects on larval behavior and identify compounds likely to play a defensive role in situ.

Renal Involvement in a French Paediatric Cohort of Patients with Lysinuric Protein Intolerance.

Lysinuric protein intolerance (LPI) is a rare autosomal recessive metabolic disorder, caused by defective transport of cationic amino acids at the basolateral membrane of epithelial cells, typically in intestines and kidneys. The SLC7A7 gene, mutated in LPI patients, encodes the light subunit (y+LAT1) of a member of the heterodimeric amino acid transporter family.The diagnosis of LPI is difficult due to unspecific clinical features: protein intolerance, failure to thrive and vomiting after weaning. Later on, patients may present delayed growth osteoporosis, hepatosplenomegaly, muscle hypotonia and life-threatening complications such as alveolar proteinosis, haemophagocytic lymphohistiocytosis and macrophage activation syndrome. Renal involvement is also a serious complication with tubular and more rarely, glomerular lesions that may lead to end-stage kidney disease (ESKD). We report six cases of LPI followed in three different French paediatric centres who presented LPI-related nephropathy during childhood. Four of them developed chronic kidney disease during follow-up, including one with ESKD. Five developed chronic tubulopathies and one a chronic glomerulonephritis. A histological pattern of membranoproliferative glomerulonephritis was first associated with a polyclonal immunoglobulin deposition, treated by immunosuppressive therapy. He then required a second kidney biopsy after a relapse of the nephrotic syndrome; the immunoglobulin deposition was then monoclonal (IgG1 kappa). This is the first observation of an evolution from a polyclonal to a monotypic immune glomerulonephritis. Immune dysfunction potentially attributable to nitric oxide overproduction secondary to arginine intracellular trapping is a debated complication in LPI. Our results suggest all LPI patients should be monitored for renal disease regularly.

Deletion of the thymidine kinase gene induces complete attenuation of the Georgia isolate of African swine fever virus.

African swine fever virus (ASFV) is the etiological agent of a contagious and often lethal viral disease of domestic pigs. There are no vaccines to control Africa swine fever (ASF). Experimental vaccines have been developed using genetically modified live attenuated ASFVs obtained by specifically deleting virus genes involved in virulence, including the thymidine kinase (TK) gene. TK has been shown to be involved in the virulence of several viruses, including ASFV. Here we report the construction of a recombinant virus (ASFV-G/V-ΔTK) obtained by deleting the TK gene in a virulent strain of ASFV Georgia adapted to replicate in Vero cells (ASFV-G/VP30). ASFV-G/P-ΔTK demonstrated decreased replication both in primary swine macrophage cell cultures and in Vero cells compared with ASFV-G/VP30. In vivo, intramuscular administration of up to 10(6) TCID50 of ASFV-G/V-ΔTK does not result in ASF disease. However, these animals are not protected when challenged with the virulent parental Georgia strain.

Endpoint bias in large Tn10-catalyzed inversions in Salmonella typhimurium.

A genetic strategy identified Salmonella typhimurium strains carrying large (> 40 kb) Tn 10-catalyzed inversions; the inverted segments were characterized by XbaI digestion and pulsed field gel electrophoresis. Two size classes of large inversions were found. More than half of the inversions extended 40-80 kb either clockwise or counterclockwise of the original Tn10 site. The remaining inversions extended up to 1620 kb (33% of the genome), but the distal endpoints of these inversions were not randomly scattered throughout the chromosome. Rather, each Tn10 repeatedly yielded similar (though not identical) inversions. The biased endpoint selection may reflect the limited search for target DNA sequences by the Tn10 transposase, and the spatial proximity of the donor and target regions in the folded S. typhimurium nucleoid. Using this interpretation, the data suggest that DNA sequences 40-80 kb clockwise and counterclockwise of the insertion site are in spatial proximity with the insertion, perhaps reflecting the organization of DNA into approximately 120-kb nucleoid domains. In addition, the data predict the spatial proximity of several distant DNA regions, including DNA sequences equidistant from the origin of DNA replication.

Biologic properties of human herpesvirus 7 strain SB.

The growth characteristics of human herpesvirus 7 strain SB (HHV-7 (SB)) were studied in human umbilical cord blood lymphocyte (CBL) cultures. The virus has approximately a 4-day growth cycle, as measured by immunofluorescence analysis, quantitation of the relative viral DNA concentration, and examination of infected cells by electron microscopy on consecutive days post-infection. By systematically varying the culture media components, improved culturing conditions were established. Activated lymphocytes were required for virus growth. HHV-7(SB) grew best in phytohemagglutinin-stimulated CBL cultured in media containing 0.01 mg/ml hydrocortisone. Addition of recombinant human interleukin 2 (IL-2) at concentrations exceeding 1-10 U/ml inhibited virus growth in most CBL cultures. Addition of exogenous IL-2 to the culture media had no effect on viral DNA production. However, the percentage of virus antigen-positive cells was highest when 0.1-1 U/ml was added to the media. Differences in the ability of individual CBL cultures to replicate HHV-7(SB) was not explained by differing CD4+ cell concentrations. However, individual cultures varied in the level of endogenous IL-2 production, which may contribute to the virus growth variability in CBL. HHV-7(SB) grew in the CD4-positive T-cell line SupT1, but not in a variety of other lymphocyte, fibroblast, or epithelial cell lines. Nine compounds were tested for antiviral activity against HHV-7 in vitro. Phosphonoformic acid inhibited virus growth with a 50% effective concentration of 4.8 microM. Ganciclovir (200 microM) and phosphonoacetic acid (100 microM) inhibited more than 90% of virus production. None of the compounds were cytotoxic at concentrations which inhibited the virus. A generalized increase in host cell protein synthesis was also observed in virus-infected cells similar to that seen in CBL infected with human herpesvirus 6.

Snoring and obstructive sleep apnea.

The most common form of sleep apnea is obstructive sleep apnea (OSA). It is characterized by the cessation of nasal airflow with persistence of ventilatory effort, as shown by paradoxical chest and abdominal movement, and varying degrees of oxygen desaturation. This article describes current methods of diagnosing OSA and available treatment for OSA and snoring.

Tonsillectomy and adenoidectomy. Laser procedures.

Laser tonsillectomy and adenoidectomy appear to be gaining popularity. Benefits of such procedures include reduced pain and edema, minimum scar tissue, and hemostasis. The benefits to the surgeon include accuracy and a clear, dry operative field. Recently, some surgeons have used lasers on a routine basis. The role of the perioperative nurse in such procedures is rapidly changing. He or she as a patient advocate must be informed of technical advances as well as benefits, risks, and costs to patients.

Virus-host interactions in persistently FMDV-infected cells derived from bovine pharynx.

Foot-and-mouth disease virus (FMDV) produces a disease in cattle characterized by vesicular lesions and a persistent infection with asymptomatic low-level production of virus in pharyngeal tissues. Here we describe the establishment of a persistently infected primary cell culture derived from bovine pharynx tissue (PBPT) infected with FMDV serotype O1 Manisa, where surviving cells were serially passed until a persistently infected culture was generated. Characterization of the persistent virus demonstrated changes in its plaque size, ability to grow in different cell lines, and change in the use of integrins as receptors, when compared with the parental virus. These results demonstrate the establishment of persistently infected PBPT cell cultures where co-adaptation has taken place between the virus and host cells. This in vitro model for FMDV persistence may help further understanding of the molecular mechanisms of the cattle carrier state.

Developmental dimorphism and expression of chemosensory-mediated behavior: habitat selection by a specialist marine herbivore.

Developmental dimorphisms provide an opportunity to compare sensory systems and behavior patterns between different forms of a single species. Alternative morphs differing in dispersal ability often show behavioral differences that mediate life-history trade-offs. We measured the behavioral responses of both long-lived, feeding larvae and short-lived, non-feeding larvae of the specialist marine herbivore Alderia modesta during habitat selection. Larvae immediately responded to waterborne cues from the adult host algae by increasing their turning rate, by changing their swimming speed in the water and by moving in rapid hops or spiraling along the bottom. These behavior patterns retained larvae in areas where the dissolved cue was initially perceived, and prolonged exposure to the cue increased the percentage of larvae that initiated metamorphosis. Despite their differences in life span and trophic mode, both larval morphs displayed similar behavior patterns when stimulated by the waterborne cue. Long-lived larvae had a stronger response, however, suggesting that settlement behavior may offset the costs of a prolonged larval life. This is the first study to examine the effects of dimorphic development on chemosensory-mediated behavior.

Waterborne and Surface-Associated Carbohydrates as Settlement Cues for Larvae of the Specialist Marine Herbivore Alderia modesta.

Larvae of the specialist marine herbivore Alderia modesta (Opisthobranchia: Ascoglossa) metamorphose in response to a chemical settlement cue from the alga Vaucheria longicaulis, the obligate adult prey. Bioactivity coeluted with both high and low molecular weight carbohydrates in solution, and with insoluble high molecular weight carbohydrates associated with the algal cell wall. Larvae metamorphosed in response to water conditioned by V. longicaulis, as well as to frozen and homogenized algal tissue. The inducer was efficiently extracted from the algae with boiling water, but after all soluble activity was extracted, residual tissue still induced larval settlement. Ethanol precipitation of a boiled-water extract followed by gel filtration chromatography showed that the precipitate contained carbohydrates of >100,000 Da molecular weight, while the supernatant contained only low molecular weight carbohydrates (<2,000 Da); in both cases all activity was associated with the carbohydrate peak. An aqueous-insoluble 4% NaOH extract was chromatographed in 7 M urea to yield a bioactive high molecular weight carbohydrate peak. Activity was not affected by proteinase K or mild acid hydrolysis, but was significantly decreased by periodate treatment. The results indicate that larvae of A. modesta metamorphose in response to both water-soluble and surface-associated carbohydrates of V. longicaulis, and that the soluble cue exists as both high and low molecular weight isoforms.

Nanosecond-to-picosecond pulse compression with fiber gratings in a compact fiber-based chirped-pulse-amplification system.

A chirped, 12-cm-long fiber Bragg grating with 10-nm spectral bandwidth was employed in place of a conventional diffraction grating pair compressor in a compact fiber-based high-energy chirped-pulseamplification system. Initial nanosecond chirped pulses from a fast-tuned laser diode were compressed to produce 1.9-ps-long, 300-nJ pulses.