High repetition-rate foam targetry for laser-plasma interaction experiments: Concept and preliminary results.

Foam targets have gained considerable importance over the last decade in laser-matter interaction. They find widespread applications such as in inertial confinement fusion and secondary sources for particles and radiation. At the same time, the advent of high repetition-rate laser systems, be they short-pulse in the tens of femtosecond regime or in the kilo-Joule nanosecond regime, calls for equally high repetition rate targetry systems. A well-established repetition-rate targetry system is the tape target. In this article, we present the successful marriage of a tape target delivery system with 3D-printed foam targets produced by two photon polymerization.

[The role of the voltage-dependent anion channels in the outer membrane of mitochondria in the regulation of cellular metabolism].

The role of the voltage-dependent anion channels (VDAC) harbored in the outer membrane of mitochondria in the regulation of cellular metabolism was investigated using an experimental model of ethanol toxicity in cultured hepatocytes. It was demonstrated that ethanol inhibits State 3 and uncoupled mitochondrial respirations, decreases the accessibility of mitochondrial adenylate kinase localized in the intermembrane space of mitochondria, and suppresses ureagenic respiration and synthesis of urea in cultured hepatocytes. Increasing the permeability of the outer mitochondrial membrane with closed VDAC with high concentrations of digitonin (> 80 microM), which creates pores in the membrane, allowing the alternative bypass of closed VDAC, and restores all reactions suppressed with ethanol. It is concluded that the effect of ethanol in hepatocytes leads to global loss of mitochondrial functions due to the closure of VDAC, which limits the free diffusion of metabolites into the intermembrane space of mitochondria. Our studies demonstrated that ethanol affects the main mitochondrial functions and revealed the role of VDAC channels in the outer mitochondrial membrane in the regulation of liver specific intracellular processes such as ureagenesis. The data obtained can be used for the development of pharmaceutical drugs that prevent the closure of VDAC in mitochondria of ethanol oxidizing liver, thus protecting liver tissue from the hepatotoxic action of alcohol.

Evaluation of RT-PCR and reverse line blot hybridization for detection and genotyping F+ RNA coliphages from estuarine waters and molluscan shellfish.

AIMS: To evaluate a PCR-based detection and typing method for faecal indicator viruses (F+ RNA coliphages) in water and shellfish, and apply the method for better understanding of the ecology and microbial source tracking potential of these viruses. METHODS AND RESULTS: Water and shellfish samples were collected over 3 years at nine estuaries in the East, West and Gulf Coasts of the USA, providing 1033 F+ RNA coliphage isolates. F+ RNA coliphage genotyping rates by reverse transcriptase-PCR-reverse line blot (RLB) hybridization ranged from 94.7% to 100% among estuaries, and were not significantly different in oysters, clams, mussels or water (P = 0.8427). Twenty samples negative by RLB were nucleotide sequenced for confirmation, and to refine RLB probes. More F+ RNA coliphages were genotyped from colder water than warmer waters, while the water salinity did not affect F+ RNA coliphage levels. CONCLUSIONS: RT-PCR-RLB was a robust method for detecting and genotyping F+ RNA coliphages from diverse coastal areas, which provided new information on the ecology of F+ RNA coliphages. SIGNIFICANCE AND IMPACT OF THE STUDY: This performance-validated F+ RNA coliphage method can be used for faecal indicator monitoring and microbial source tracking, to protect recreational bathers and shellfish consumers from exposure to pathogenic virus and their disease risks.

Development and evaluation of methods to detect coliphages in large volumes of water.

New and improved methods have been developed to detect somatic and male-specific coliphages in large volumes of water by single agar layer (SAL), enrichment and membrane filter methods. Somatic coliphages were detected efficiently on E. coli hosts C and CN13, male-specific coliphages were detected more efficiently on E. coli Famp than on Salmonella typhimurium WG49 and both types of coliphages were detected simultaneously on E. coli C3000. For water volumes of up to 100 ml, the SAL method was efficient and reliable. For water volumes of <1 L and as many as 10 multiple 1 L volumes, the enrichment method was efficient in detecting very low numbers of coliphages. Membrane filter methods, in which coliphages were adsorbed to and eluted from filters, also were relatively efficient, but they were less efficient than SAL and enrichment methods and were considered to be more cumbersome. For filter adsorption-elution methods, coliphage recoveries were most efficient for cellulose ester filters, less efficient for electropositive 1 MDS filters and least efficient for a direct membrane filter method. Overall, the enrichment method was preferred because of its ability to easily and rapidly detect low levels of coliphages in large sample volumes by either presence-absence or most probable number quantification.

Detection of human papillomavirus DNA by in situ hybridization and polymerase chain reaction in human papillomavirus equivocal and dysplastic cervical biopsies.

One hundred twenty-one paraffin-embedded cervical biopsy specimens were tested for the presence of human papillomavirus (HPV) DNA by in situ hybridization and polymerase chain reaction. By in situ hybridization using probes for HPV types 6/11, 16/18, 31/33/35, 42/43/44, 51/52, and 45/56, HPV DNA was found in none of 20 normal/squamous metaplasia biopsy specimens, in one of 76 HPV equivocal biopsy specimens, in seven of 12 condyloma/mild dysplasia biopsy specimens, and in 12 of 13 moderate/severe dysplasia biopsy specimens. Polymerase chain reaction using HPV L1 consensus sequence primers followed by filter hybridization of the amplification products was positive for HPV DNA in two of 20 normal/squamous metaplasia biopsy specimens, in 23 of 76 HPV equivocal biopsy specimens, in eight of 12 condyloma/mild dysplasia biopsy specimens, and in 12 of 13 moderate/severe dysplasia biopsy specimens. Among biopsies that tested positive by polymerase chain reaction but that were negative by in situ hybridization, the most commonly identified HPV was type 16. We conclude that although HPV equivocal biopsy specimens contain HPV DNA more frequently than histologically normal tissue, the majority of biopsy specimens in this category test negative for HPV DNA. The clinical significance of a positive test for HPV, in the absence of unequivocal histologic changes, remains to be determined.

Duodenal bile acids among children: keto derivatives and aerobic small bowel bacterial overgrowth.

Duodenal bile acids, identified by gas-liquid chromatography (GLC) and gas chromatography-mass spectrometry (GC-MS), were correlated with quantitative aerobic and anaerobic duodenal culture in 26 children with enteropathies. Four patients whose duodenal fluid contained either greater than or equal to 10(6) gram-negative aerobes or greater than or equal to 10(6) aerobic lactobacilli per milliliter had a significantly greater molar percentage of keto-bile acids (32.3 +/- 8.4%) than did 19 controls (0.72 +/- 1.50%) chosen because duodenal fluid contained less than or equal to 10(4) bacteria per milliliter or three other patients with greater than or equal to 10(6) anaerobes (6.1 +/- 4.6%). As expected, free bile acids were seen in greater quantities (10.75 +/- 3.25%) among the patients with anaerobic overgrowth or aerobic Lactobacillus overgrowth than among the controls (1.6 +/- 1.0%) or the other three aerobic overgrowth patients (2.2 +/- 1.4%). Incubation of glycocholate or glycochenodeoxycholate for 60 h with Eubacterium tortuosum from one patient or Escherichia coli from another produced the types of bile acids found in the duodenum of those patients. Successful antibacterial therapy improved gastrointestinal function and normalized duodenal bile acids not only among patients with anaerobic overgrowth but also among those with pure aerobic overgrowth. These data suggest that pure aerobic bacterial overgrowth syndrome occurs in children, and that altered duodenal bile acid composition may play a pathophysiologic role in this disorder.

Prediction of the concentrations in rat tissues of the intravenous anaesthetic methohexital from a nonlinear pharmacokinetic model.

A nonlinear pharmacokinetic model that describes the tissue distribution of intravenous anaesthetics was evaluated against experimental values for methohexital in the rat. There was excellent agreement between experimental and theoretical values for brain tissue, and good agreement for blood and adipose tissue. Agreement for lean tissue was good if it was assumed that some adipose tissue was present in skeletal muscle. Agreement was poor for all other visceral tissues. The experimental results justify further development of this mathematical model for use in accounting for differences in tissue distribution of anaesthetics, especially under various physiological conditions.

Enteric Bacterial and Viral Pathogens and Indicator Bacteria in Hard Shell Clams.

Enteric bacteria and virus levels were determined in hard shell clams, Mercenaria mercenaria , harvested from areas open or closed for commercial shellfishing on the basis of total coliform levels in water. Four pairs of open and closed stations were sampled seasonally over a 1-year period. Enteric viruses were isolated from 3 of 13 100-g clam samples from open beds and 6 of 15 samples from closed beds. Salmonella was found in 1 of 15 samples from closed areas, but not in any samples from open areas. No Shigella or Yersinia were isolated from clams taken from either open or closed beds. Levels of Vibrio parahaemolyticus , an indigenous estuarine microorganism, were similar in clams from open and closed areas. No statistically significant difference was found in the occurrence of enteric viruses in clams from open and closed areas. Product-moment correlations between concentrations of enteric viruses and bacteria in clams or water demonstrated no statistically significant correlations between virus concentrations in clams and total coliforms or fecal coliforms in water or total coliforms, fecal coliforms, fecal streptococci or aerobic plate counts in clams.