Search results for "Response"

Mode of selection and experimental evolution of antiviral drugs resistance in vesicular stomatitis virus

2004

Abstract The possession of an antiviral resistance mutation benefits a virus when the corresponding antiviral is present. But does the resistant virus pay a fitness cost when the antiviral is absent? Would an evolutionary history of association between a genotype and a resistance mutation overcome this cost by changes compensating the harmful side-effect of resistance mutations? Are combined therapies more effective against the rise of resistant viruses or against evolutionary compensations? To explore all these questions, we took an experimental evolution approach. After selecting vesicular stomatitis virus (VSV) populations able to replicate under increasing concentrations of ribavirin an…

Proteinaceous bacterial toxins and pathogenesis of sepsis syndrome and septic shock: the unknown connection

1994

Inducing properties of rifampicin and rifabutin for selected enzyme activities of the cytochrome P-450 and UDP-glucuronosyltransferase superfamilies …

1996

Important species differences have been reported concerning the induction properties of rifampicin towards enzymes of the P-450 superfamily. Mice, rabbits and humans are far more responsive than rats and guinea pigs. In the present study a strong induction of cytochrome P-450 3A-dependent enzyme activities was observed in female rat liver microsomes after high dose treatment (> or = 250 mg/kg/day for 9 days) with rifampicin, resulting in an up to 30-fold enhanced hydroxylation rate of testosterone in the 2 beta-, 6 beta- and 15 beta-position in vitro. Other cytochrome P-450 isozyme-selective reactions were not, or only marginally, affected. A steep increase in cytochrome P-450 3A activity o…

In vitro activity of LY333328, a new glycopeptide, against extracellular and intracellular vancomycin-resistant enterococci.

2000

The objectives of the study were to observe the activity of LY333328, a new semisynthetic glycopeptide, compared to that of vancomycin against six strains of Enterococcus faecium and Enterococcus faecalis, including four vancomycin-resistant strains. Bacteria ingested by polymorphonuclear leukocytes (PMN) as well as extracellular bacteria were studied using a colony count method. The activity against intracellular bacteria was tested with the drugs present in the extracellular medium, as well as after preincubating the PMN and removal of the drugs. LY333328 is active against the tested enterococci, regardless of their susceptibility to vancomycin, with MICs of 1-2 mg/l. It is bacteriostatic…

Factors influencing hospital infection control policies in Italian hospitals

2003

A study was undertaken to determine the resources available in Italian hospitals for the control of nosocomial infections and the factors favouring a successful approach. During January-May 2000 a questionnaire about infection control was sent to the hospital health director of all Italian National Health System hospitals treating acute patients and with more than 3500 admissions in 1999. An active programme was defined as a hospital infection control committee (HICC) meeting at least four times in 1999, the presence of a doctor with infection control responsibilities, a nurse employed in infection control and at least one surveillance activity and one infection control guideline issued or …

Current and future challenges in HCV: insights from an Italian experts panel

2017

Background: The recent availability of direct acting antiviral drugs (DAAs) has drastically changed hepatitis C virus (HCV) treatment scenarios, due to the exceedingly high rates of sustained virological response (SVR) and excellent tolerability allowing for treatment at all disease stages. Methods: A panel of Italian experts was convened twice, in November 2016 and January 2017, to provide further support on some open issues and provide guidance for personalized HCV care, also in light of forthcoming regimens. Results and conclusions: Treatment recommendations issued by international and national liver societies to guide clinicians in the management of HCV infection are constantly updated …

Reduction of spherical-aberration impact in microscopy by wavefront coding

2009

In modern high-NA optical scanning instruments, like scanning microscopes, the refractive-index mismatch between the sample and the immersion medium introduces a significant amount of spherical aberration when imaging deep inside the specimen, spreading out the impulse response. Since such aberration depends on the focalization depth, it is not possible to achieve a static global compensation for the whole 3D sample in scanning microscopy. Therefore a depth-variant impulse response is generated. Consequently, the design of pupil elements that increase the tolerance to this aberration is of great interest. In this paper we report a hybrid technique that provides a focal spot that remains alm…

Possible involvement of nitric oxide in morphine-induced miosis and reduction of intraocular pressure in rabbits.

2006

The role of μ3 opioid receptors in morphine-induced intraocular pressure (IOP) lowering effect and miosis was evaluated in conscious, dark-adapted New Zealand white (NZW) rabbits using a masked-design study. IOP and pupil diameter (PD) measurements were taken at just before and 0.5, 1, 2, 4, 6 h after monolateral instillation of morphine (10, 50 and 100 μg/30 μl) as compared to vehicle administered in the contralateral eye. Morphine-induced ocular effects were challenged by a pre-treatment with the non-selective opioid receptor antagonist, naloxone (100 μg/30 μl), the nitric oxide synthase inhibitor, Nω-nitro-l-arginine methyl ester (l-NAME, 1%, 30 μl), or the non-selective μ3 opioid recept…

ALDH-2 deficiency increases cardiovascular oxidative stress--evidence for indirect antioxidative properties.

2007

Abstract Mitochondrial aldehyde dehydrogenase (ALDH-2) reduces reactive oxygen species (ROS) formation related to toxic aldehydes; additionally, it provides a bioactivating pathway for nitroglycerin. Since acetaldehyde, nitroglycerin, and doxorubicin treatment provoke mitochondrial oxidative stress, we used ALDH-2−/− mice and purified recombinant human ALDH-2 to test the hypothesis that ALDH-2 has an indirect antioxidant function in mitochondria. Antioxidant capacity of purified ALDH-2 was comparable to equimolar doses of glutathione, cysteine, and dithiothreitol; mitochondrial oxidative stress was comparable in C57Bl6 and ALDH-2−/− mice after acute challenges with nitroglycerin or doxorubi…

Manganese superoxide dismutase and aldehyde dehydrogenase deficiency increase mitochondrial oxidative stress and aggravate age-dependent vascular dys…

2008

AimsImbalance between pro- and antioxidant species (e.g. during aging) plays a crucial role for vascular function and is associated with oxidative gene regulation and modification. Vascular aging is associated with progressive deterioration of vascular homeostasis leading to reduced relaxation, hypertrophy, and a higher risk of thrombotic events. These effects can be explained by a reduction in free bioavailable nitric oxide that is inactivated by an age-dependent increase in superoxide formation. In the present study, mitochondria as a source of reactive oxygen species (ROS) and the contribution of manganese superoxide dismutase (MnSOD, SOD-2) and aldehyde dehydrogenase (ALDH-2) were inves…