Activities of levofloxacin, ofloxacin, and ciprofloxacin, alone and in combination with amikacin, against acinetobacters as determined by checkerboard and time-kill studies.

A total of 101 Acinetobacter genospecies (77 Acinetobacter baumannii strains and 24 non-A. baumannii strains) were tested for their susceptibilities to levofloxacin, ofloxacin, and ciprofloxacin and for synergy between the quinolones and amikacin by checkerboard titration and time-kill analyses. The MICs at which 50% of the isolates are inhibited (MIC50)/MIC90s for the 101 strains were as follows (in micrograms per milliliter): levofloxacin, 0.25/16.0; ofloxacin, 0.5/32.0; ciprofloxacin, 0.25/> 64.0; and amikacin, 1.0/> 32.0. At empiric breakpoints of < or = 2.0 microg/ml, 61% of the strains were susceptible to all three quinolones. At a breakpoint of < or = 16.0 microg/ml, 84% of the strains were susceptible to amikacin. Checkerboard titrations yielded synergistic fractional inhibitory concentration (FIC) indices (< or = 0.5) for one strain with levofloxacin and amikacin and for two strains with ofloxacin and amikacin. Indices of > 0.5 to 1.0 were seen for 57, 54, and 55 strains with levofloxacin plus amikacin, ofloxacin plus amikacin, and ciprofloxacin plus amikacin, respectively, and indices of > 1.0 in 43, 45, and 46 strains, respectively, were found with the above three combinations. No strains yielded antagonistic FIC indices (> 4.0). Most FIC results of > 1.0 occurred in strains for which the quinolone MICs were > 2.0 microg/ml and for which the amikacin MICs were > or = 32.0 microg/ml. By contrast, synergy (defined as > or = 2 log10 decrease compared to the more active compound alone by time-kill analysis) was found in all seven strains tested for which the quinolone MICs were < or = 2.0 microg/ml. For eight other strains for which the quinolone MICs were > 2.0 microg/ml as determined by time-kill analysis, quinolone and amikacin concentrations in combination were usually too high to permit clinical use. Time-kill analysis was found to be more sensitive in detecting synergy than was the checkerboard method.     

Antipneumococcal activities of cefpirome and cefotaxime, alone and in combination with vancomycin and teicoplanin, determined by checkerboard and time-kill methods.

The checkerboard titration method was used to test the synergy of cefpirome and cefotaxime with teicoplanin or vancomycin against 35 penicillin-susceptible, 34 penicillin-intermediate, and 31 penicillin-resistant pneumococci. The MICs at which 50 and 90% of isolates are inhibited (MIC50s and MIC90s, respectively) of both cefpirome and cefotaxime were 0.016 and 0.06 microgram/ml, respectively, for penicillin-susceptible strains and 0.125 and 0.5 microgram/ml, respectively, for penicillin-intermediate strains. The MIC50s and MIC90s of cefotaxime for penicillin-resistant strains were 1.0 and 2.0 micrograms/ml, respectively, and those of cefpirome were 0.5 and 1.0 microgram/ml, respectively. All pneumococci were inhibited by cefpirome at MICs of < or = 1.0 microgram/ml. The MIC50s and MIC90s of vancomycin and teicoplanin (0.25 and 0.25 microgram/ml and 0.03 and 0.03 microgram/ml, respectively) did not differ for the three groups. Checkerboard synergy studies showed that cefpirome and vancomycin showed synergy for 31 strains (fractional inhibitory concentration [FIC] indices, < or = 0.5) cefpirome and teicoplanin showed synergy for 18 strains, cefotaxime and vancomycin showed synergy for 51 strains, and cefotaxime and teicoplanin showed synergy for 27 strains. Cefpirome and vancomycin had FIC indices indicating indifference (2.0) for two strains, and cefotaxime and vancomycin had FIC indices indicating indifference for one strain. All other FIC indices indicating indifference or additivity were > 0.5 to 1.0. No FIC indices indicating antagonism (> 4.0) were found. Synergy between beta-lactams and glycopeptides for three susceptible, three intermediate, and three resistant strains were tested by the time-kill assay, and all combinations were synergistic by this method. Synergy between cephalosporins and glycopeptides can be demonstrated and may be useful for the treatment of pneumococcal infections, especially meningitis.     

Human herpesvirus portal proteins: Structure,function, and antiviral prospects

Herpesviruses (Herpesvirales) and tailed bacteriophages (Caudovirales) package their dsDNA genomes through an evolutionarily conserved mechanism. Much is known about the biochemistry and structural biology of phage portal proteins and the DNA encapsidation (viral genome cleavage and packaging) process. Although not at the same level of detail, studies on HSV‐1, CMV, VZV, and HHV‐8 have revealed important information on the function and structure of herpesvirus portal proteins. During dsDNA phage and herpesviral genome replication, concatamers of viral dsDNA are cleaved into single length units by a virus‐encoded terminase and packaged into preformed procapsids through a channel located at a single capsid vertex (portal). Oligomeric portals are formed by the interaction of identical portal protein monomers. Comparing portal protein primary aa sequences between phage and herpesviruses reveals little to no sequence similarity. In contrast, the secondary and tertiary structures of known portals are remarkable. In all cases, function is highly conserved in that portals are essential for DNA packaging and also play a role in releasing viral genomic DNA during infection. Preclinical studies have described small molecules that target the HSV‐1 and VZV portals and prevent viral replication by inhibiting encapsidation. This review summarizes what is known concerning the structure and function of herpesvirus portal proteins primarily based on their conserved bacteriophage counterparts and the potential to develop novel portal‐specific DNA encapsidation inhibitors.     

Reducing seclusion and restraint: meeting the organizational challenge

The Mohawk Valley Psychiatric Center has experienced a major reduction in the use of seclusion and restraint in the past five years. It has used the traditional quality improvement (QI) tools like the Plan Do Check Act, Flowcharts, Fishbone diagrams, and Parieto Charts as suggested in the QI literature. The original work to reduce seclusion and restraint are described in two previous articles by Visalli and McNasser. This article describes the additional work since that time. The seclusion/restraint rate in adult service per 1,000 patient days is 0.13 for restraint and 0.15 for seclusion for calendar year 1998. Children and youth service also has comparatively minimal use of seclusion and restraint. The success of this program is attributed to the organizational leadership and the interdisciplinary approach taken to provide individualized treatment. Many of the initiatives stem from a working relationship with patients on how to improve customer service.     

In vitro CO2-induced ROS production impairs cell cycle in SH-SY5Y neuroblastoma cells

Purpose

We evaluated in vitro the role of CO₂-induced oxidative stress on the expression of proteins involved in cell-cycle regulation of neuroblastoma cells.

Methods

SH-SY5Y cells were exposed to CO₂ at 15 mmHg pressure (100 %) for 4 h and then moved to normal condition for 24 h. Control cells were maintained in 5 % CO₂ for the same time. ROS production was determined by fluorescent staining with H2DCF-DA. DNA damage was measured by COMET assay. p53 protein expression was analyzed by western blot and confocal laser scanning microscopy was used to evaluate its sub-cellular localization. Cyclin expression was quantified by real-time PCR and western blot. Cell-cycle analysis was performed by FACS.

Results

CO₂ incubation was associated with an increase in ROS production (p < 0.01), cell DNA damage mainly after 24 h (12 % increase of tail DNA content and 4-fold increase of tail length) and a significant up-regulation in p53 expression at 24 h with an intense nuclear staining. In CO₂-treated cells, we observed an S-phase arrest in correlation with a reduction of cyclin B1 expression.

Conclusions

In vitro-simulated pneumoperitoneum environment with CO₂ induces oxidative stress and cell DNA damage, leading to p53 up-regulation involved in cell-cycle arrest of neuroblastoma cells.     

Multigenerational mitochondrial alterations in pneumocytes exposed to oil fly ash metals

Oil fly ash (OFA), containing high amounts of transition metals, is among the most reactive airborne particulate matter emissions, which have been associated with several diseases, such as chronic obstructive pulmonary diseases (COPD), lung cancer, and cardiovascular diseases. The aim of the present study was to evaluate mitochondrial alterations in OFA-exposed cultured pneumocytes and in their progeny. Alveolar epithelial cells (A549 line) were exposed either to an OFA water solution, containing 68.8 μM vanadium (V), 110.4 μM iron (Fe), and 18.0 μM nickel (Ni), or to the individual metal solutions. Structural and functional mitochondrial parameters were determined in exposed cultures and in 3 consecutive subcultures. OFA, V and Fe solutions caused a time-dependent loss of mitochondrial enzymatic activity, glutathione depletion, generation of lipid hydroperoxides, hydrogen peroxide and other reactive oxygen species, especially in G(0)-G(1) phase cells, accompanied by a decrease in mitochondrial mass and transmembrane potential. Mitochondrial alterations were partly transmissible to daughter cells for up to 3 generations. Fe and especially V were responsible for the observed mitochondrial alterations in pneumocytes exposed to OFA. Spread of mitochondrial dysfunctions to daughter cells is expected to amplify oxidative stress in the respiratory epithelium and to play an important role in the pathogenesis of respiratory diseases.     

CT-MR integrated diagnostic imaging of the oral cavity: neoplastic disease

The oral cavity is a complex anatomical region consisting of different anatomical sites and subsites. Cancer undoubtedly represents the most frequent and relevant disease of this region. Clinical examination is often the first approach to oral cavity tumours. Cross-sectional computed tomography (CT) and magnetic resonance imaging (MRI) play a key role in staging locoregional disease by demonstrating submucosal spread and involvement of deep layers; evaluation of specific pathways of spread to peculiar anatomical subsites is also fundamental information that can be obtained with these techniques. The purpose of this paper is to illustrate CT and MRI findings of anatomical subsites involved by tumours of the oral cavity.     

Vaccination with a HSV-2 UL24 mutant induces a protective immune response in murine and guinea pig vaginal infection models

The rational design and development of genetically attenuated HSV-2 mutant viruses represent an attractive approach for developing both prophylactic and therapeutic vaccines for genital herpes. Previously, HSV-2 UL24 was shown to be a virulence determinant in both murine and guinea pig vaginal infection models. An UL24-βgluc insertion mutant produced syncytial plaques and replicated to nearly wild type levels in tissue culture, but induced little or no pathological effects in recipient mice or guinea pigs following vaginal infection. Here we report that immunization of mice or guinea pigs with high or low doses of UL24-βgluc elicited a highly protective immune response. UL24-βgluc immunization via the vaginal or intramuscular routes was demonstrated to protect mice from a lethal vaginal challenge with wild type HSV-2. Moreover, antigen re-stimulated splenic lymphocytes harvested from immunized mice exhibited both HSV-2 specific CTL activity and IFN-γ expression. Humoral anti-HSV-2 responses in serum were Th1-polarized (IgG_2a > IgG₁) and contained high-titer anti-HSV-2 neutralizing activity. Guinea pigs vaccinated subcutaneously with UL24-βgluc or the more virulent parental strain (186) were challenged with a heterologous HSV-2 strain (MS). Acute disease scores were nearly indistinguishable in guinea pigs immunized with either virus. Recurrent disease scores were reduced in UL24-βgluc immunized animals but not to the same extent as those immunized with strain 186. In addition, challenge virus was not detected in 75% of guinea pigs subcutaneously immunized with UL24-βgluc. In conclusion, disruption of the UL24 gene is a prime target for the development of a genetically attenuated live HSV-2 vaccine.