Efficacy of Telavancin in Comparison to Linezolid in a Porcine Model of Severe Methicillin-Resistant Staphylococcus aureus Pneumonia.

Current guidelines recommend vancomycin and linezolid as first-line agents against methicillin-resistant Staphylococcus aureus (MRSA) nosocomial pneumonia. Telavancin is a potential new therapeutic alternative, specifically in monomicrobial MRSA pneumonia. This study compared the efficacies of telavancin versus linezolid in a porcine model of severe MRSA pneumonia. In 18 mechanically ventilated pigs (32.11 ± 1.18 kg), 75 ml of 106 CFU/ml of MRSA was administered into each pulmonary lobe. After the onset of pneumonia, pigs were randomized into three groups: a control group, a group receiving 22.5 mg/kg of body weight every 24 h (q24h) of telavancin, and a group receiving 10 mg/kg q12h of linezolid intravenously. Tracheal aspirate and bronchoalveolar lavage (BAL) fluids were cultured every 24 h. After 48 h of treatment, tissue samples were collected from the ventral and dorsal sections of each lobe. Microbiological and histopathological analyses were performed. Lung tissue concentrations differed among the groups (P = 0.019), with the lowest MRSA lung burden in the telavancin group (P < 0.05 versus the control). MRSA was detected in 46.7%, 40.0%, and 21.7% of the lung tissue samples from the control, linezolid, and telavancin groups, respectively (P < 0.001). MRSA concentrations differed among the groups in tracheal aspirate fluid (P = 0.011) but not in BAL fluid. Furthermore, there was no increased risk of kidney injury during telavancin use. Thus, telavancin has higher bactericidal efficacy than linezolid during the first 48 h of treatment in a porcine model of severe MRSA pneumonia. However, studies are needed to confirm the benefits of telavancin in treating MRSA nosocomial pneumonia.

In-vitro analysis of a novel 'add-on' silicone cuff to improve sealing properties of tracheal tubes.

Leakage of colonised oropharyngeal secretions across the tracheal tube cuff may cause iatrogenic pulmonary infection. We studied a novel 'add-on' cuff, which can be inserted over an existing tracheal tube and advanced into the subglottic region. The physical properties of the novel silicone cuff (BronchoGuard, Ciel Medical, USA) were evaluated in comparison with the Hi-Lo® tracheal tube. In a bench study, we identified saline inflation volumes required to transmit pressures between 15 and 30 cmH2 O against artificial tracheas of 18, 20 and 22 mm internal diameter. We computed cuff compliance, and minimal inflation volume to achieve air sealing during mechanical ventilation. Finally, we compared the leakage flow rate of artificial saliva across the novel cuff. On average, the mean (SD) inflation volumes necessary to transmit tracheal pressures of 15, 20, 25 and 30 cmH2 O were 4.1 (2.2), 4.4 (2.3), 4.6 (2.4) and 4.8 (2.4) ml for the novel cuff and 7.7 (2.5), 8.0 (2.6), 8.4 (2.6) and 8.7 (2.7) ml for the Hi-Lo tube, respectively (p < 0.001). The minimal inflation volumes to achieve air sealing were 3.8 (0.9) and 10.5 (2.1) ml (p < 0.001), which resulted in transmitted tracheal pressures of 8.3 (9.8) and 27.6 (34.8) cmH2 O (p < 0.001). Compliance was 0.026 (0.004) and 0.616 (0.324) ml.cmH2 0-1 , respectively (p < 0.001). Although massive leak was found when the novel cuff transmitted pressures ≤ 20 cmH2 O against the trachea, leakage was avoided with pressures ≥ 25 cmH2 O, owing to optimal contact between the cuff and the tracheal wall. In contrast, the standard cuff consistently leaked irrespective of the pressure. We conclude that the novel cuff has advantageous properties that warrant clinical corroboration.

Laboratory assessment of the quality of adult and neonatal red cell concentrates manufactured from whole blood, exchange transfusion or intrauterine transfusion red cell units.

BACKGROUND: We evaluated the quality of red cell components in additive solution over 42 days of storage when re-manufactured from neonatal exchange transfusion (ExTx) or intrauterine transfusion (IUT) units on day 7 for issue to adults, neonates or infants. MATERIALS AND METHODS: Red cell concentrates (RCC) manufactured from WB were compared to RCC re-manufactured from ExTx or IUT on day 7, and red cell splits (RCS) manufactured from WB were compared to RCS re-manufactured from ExTx or IUT on day 7. All components were stored at 2-6°C and tested throughout storage until day 42 for in vitro parameters of red cell quality. One RCS manufactured from each of WB, ExTx or IUT, was irradiated on day 14 and tested on day 28 along with a non-irradiated RCS from the same unit. RESULTS: All the re-manufactured arms had no worse haemolysis, red cell microvesicle (RCMV) release or ATP over storage compared to controls. All arms complied with the 0·8% haemolysis UK specification, except for re-manufactured RCS from the IUT arm irradiated on day 14 and tested on day 28. Re-manufactured units had significantly decreased potassium levels compared to control over storage (P < 0·001 all). CONCLUSION: RCC or RCS re-manufactured from ExTx or IUT units on day 7 are suitable for transfusion up to the standard day 35 of storage. Re-manufactured RCS from ExTx units (but not IUT), may be irradiated up to day 14 and stored for 14 days post-irradiation.

In vitro quality of apheresis platelets divided into paediatric-sized units and stored in PVC bags plasticised with TOTM, BTHC or DINCH.

BACKGROUND AND OBJECTIVES: Two of the predictive factors of the quality of small volumes of platelets suitable for paediatric use are bag size and material. This study evaluated the storage properties of paediatric platelet aliquots in TOTM-, BTHC- or DINCH-PVC bags. METHODS/MATERIALS: (i) Three apheresis platelet concentrates (PC) were pooled and split into three units. One was retained as an adult unit (control; polyolefin bag). The second and third units were split into four MacoPharma TOTM-PVC and BTHC-PVC paediatric bags, respectively. (ii) Two apheresis PC were pooled and split into two units. One PC was retained as an adult unit, and the other was split into four Fresenius DINCH-PVC paediatric bags. Testing was performed on storage for pH, blood gases, hypotonic shock response, soluble CD62P, LDH, glucose and lactate, ATP, CD62P, CD63, platelet-derived microparticles and annexin V. RESULTS: The volumes, platelet yields and pH of all paediatric units met local specifications. The TOTM-PVC bag showed no worse quality than the adult bag up to day 7 for all parameters studied, and it maintained pH higher than BTHC-PVC and DINCH-PVC over storage. The BTHC-PVC bag was shown to be the most gas permeable; however, it had the highest glucose consumption rates and the highest platelet activation. CONCLUSION: All bags showed an acceptable in vitro quality. Overall, the TOTM-PVC paediatric bag showed better platelet quality compared to the other storage bags, whereas storage in the BTHC-PVC bag resulted in poorer platelet quality.

Intestinal helminth infection impacts the systemic distribution and function of the naive lymphocyte pool.

Homeostasis is a fundamental principle of biological systems. A paradigm of immune homeostasis is the remarkably constant number of naive T and B lymphocytes in the body that continuously circulate through the secondary lymphoid organs to maximize immune surveillance. Whether the dynamics and distribution of the systemic naive lymphocyte pool is affected following organ-specific infection is not known. Here we show that, following infection of mice with an enteric helminth, naive T and B lymphocytes accumulate in the T helper type 2-reactive mesenteric lymph node while they are concurrently depleted from non-draining peripheral lymph nodes. This systemic redistribution of naive lymphocytes is sustained into the chronic phase of the infection, requires lymphotoxin beta receptor-dependent signals and is associated with a reduced ability of parasitized animals to mount antigen-specific cellular and humoral immune responses to heterologous immunization or infection at peripheral sites. Our data suggest that the function of the homeostatic naive lymphocyte pool can be modulated by its systemic distribution following infection and may provide a novel concept underlying compromised immune responsiveness at peripheral sites in helminth-infected individuals.

Synthesis and complexing properties of cyclic benzylopeptoids - a new family of extended macrocyclic peptoids.

An efficient protocol for the solid-phase synthesis of six members of a new class of extended macrocyclic peptoids (based on ortho-, meta- and para-N-(methoxyethyl)aminomethyl phenylacetyl units) is described. Theoretical (DFT) and experimental (NMR) studies on the free and Na+-complexed cyclic trimers (3-5) and tetramers (6-8) demonstrate that annulation of the rigidified peptoids can generate new hosts with the ability to sequestrate one or two sodium cations with the affinities and stoichiometries defined by the macrocycle morphology. Ion transport studies have been also performed in order to better appreciate the factors promoting transmembrane cation translocation.

Quality of red cells after combination of prion reduction and treatment with the intercept system for pathogen inactivation.

BACKGROUND AND OBJECTIVES: The pathogen inactivation (PI) INTERCEPT Blood System for Red Blood Cells utilises amustaline (S-303) to inactivate a broad range of pathogens in red cell concentrates (RCC). The aim of this study was to investigate the effect on red cell quality of INTERCEPT treatment with and without prion reduction. METHODS/MATERIALS: Five pools of five RCC each were prepared. These were split and treated as follows: (i) stored at 2-6 °C for 18 h, (ii) stored at 18-24 °C for 18 h, (iii) PI-treated, (iv) PI-treated then prion reduced and (v) prion reduced then PI-treated. Prior to storage, PI-treated RCC underwent an exchange step to remove S-303 and other breakdown products. Components were tested throughout 35 days of storage for in vitro parameters of red cell quality. RESULTS: All RCC met specification for volume and haemoglobin content. Haemolysis, microvesicle formation, supernatant potassium and deformability were lower and ATP levels higher in PI-treated units when compared with control units. The effect of prion reduction in addition to PI treatment was minimal in all parameters tested except haemolysis, which was increased in units prion-reduced after being PI-treated. CONCLUSION: The PI-treatment process did not increase red cell haemolysis or decrease ATP levels over storage. The lower haemolysis and supernatant potassium levels in treated RCC compared with control RCC were attributed to the exchange step. The effects of combining PI treatment and prion reduction were not more than additive when prion reduction precedes PI treatment.

Kinship analysis of brook trout Salvelinus fontinalis during their breeding migration.

Microsatellite markers were used to test whether groups of pre-spawning adult brook trout Salvelinus fontinalis from the same population and captured at the same location during their breeding migration comprised kin. Only weak evidence for kin associations was found at the onset of breeding: the proportion of kin captured at the same location was low and similar to the proportion found across all locations and the average relatedness of S. fontinalis captured at the same location was low. A dilution of kin associations from the feeding to breeding phase is hypothesized to stem from mainly natural mortality that reduces family size by the adult stage. The results illustrate the dynamic nature of kin associations between consecutive life stages, even within the same fish population.

Does Ménière's Disease in the Elderly Present Some Peculiar Features?

Object. Aim of our study was to establish some peculiar features of Ménière's Disease (MD) in a group of elderly MD patients, in which the first vertigo spell happened when over 65 years old. Material and Methods. We analyzed a group of 73 younger than 65-years-old and a group of 30 elderly MD patients. All patients underwent a neurotological evaluation, an anamnestic evaluation including a lifetime history of migraine, and blood withdrawal for autoantibody screening. Results. Some differences were found between elderly and younger MD patients. Elderly MD patients presented a higher prevalence of Tumarkin attacks and a lower prevalence of lifetime history of migraine; moreover, they presented a faster develop of hearing loss and vertigo spells than a subgroup of 32 younger patients matched for the duration of illness. Conclusions. Some clinical features of MD in elderly have been pointed out. Particularly, the lower rate of migrainous history and positivity for autoantibodies often associated with MD, in our opinion, support the hypothesis of a vascular disorder acting as a predisposing factor for MD in elderly.

Can baseball improve balance in blind subjects?

AIM: Baseball, one of the most popular sports in the world, is a fast-moving sport that requires various motor abilities. Baseball is played also by blind subjects that participate in many other sports. In this study, we evaluated the role of the Italian modified version of baseball for blind subjects on balance. METHODS: This modified version of baseball maintains the fast-moving characteristic ensuring the athlete safety. Forty total blind subjects were enrolled: 20 baseball athletes and 20 sedentary participants, as control. The balance was evaluated using the Fukuda Test and Tinetti Test, both in silence and in noise. RESULTS: This baseball game may help to improve the balance ability in blind subjects. The balance was significantly improved in blind athletes as compared with blind sedentary subjects. CONCLUSION: Given the peculiar characteristics of play, this modified version of baseball seems effective in improving various motor skills that, once transferred into daily activities, may significantly ameliorate the quality of life of blind subjects.

Cosmic ray electrons and positrons from supernova explosions of massive stars.

We attribute the recently discovered cosmic ray electron and cosmic ray positron excess components and their cutoffs to the acceleration in the supernova shock in the polar cap of exploding Wolf-Rayet and red supergiant stars. Considering a spherical surface at some radius around such a star, the magnetic field is radial in the polar cap as opposed to most of 4pi (the full solid angle), where the magnetic field is nearly tangential. This difference yields a flatter spectrum, and also an enhanced positron injection for the cosmic rays accelerated in the polar cap. This reasoning naturally explains the observations. Precise spectral measurements will be the test, as this predicts a simple E;{-2} spectrum for the new components in the source, steepened to E;{-3} in observations with an E;{-4} cutoff.

Rate, extent and concentration dependence of histamine-evoked Weibel-Palade body exocytosis determined from individual fusion events in human endothelial cells.

The rate, concentration dependence and extent of histamine-evoked Weibel-Palade body (WPB) exocytosis were investigated with time-resolved fluorescence microscopy in cultured human umbilical vein endothelial cells expressing WPB-targeted chimeras of enhanced green fluorescent protein (EGFP). Exocytosis of single WPBs was characterized by an increase in EGFP fluorescence, morphological changes and release of WPB contents. The fluorescence increase was due to a rise of intra-WPB pH from resting levels, estimated as pH 5.45+/-0.26 (s.d., n=144), to pH 7.40. It coincided with uptake of extracellular Alexa-647, indicating the formation of a fusion pore, prior to loss of fluorescent contents. Delays between the increase in intracellular free calcium ion concentration evoked by histamine and the first fusion event were 10.0+/-4.42 s (n=9 cells) at 0.3 microM histamine and 1.57+/-0.21 s (n=15 cells) at 100 microM histamine, indicating the existence of a slow process or processes in histamine-evoked WPB exocytosis. The maximum rates of exocytosis were 1.20+/-0.16 WPB s(-1) (n=9) at 0.3 microM and 3.66+/-0.45 WPB s(-1) at 100 microM histamine (n=15). These occurred 2-5 s after histamine addition and declined to lower rates with continued stimulation. The initial delays and maximal rate of exocytosis were unaffected by removal of external Ca2+ indicating that the initial burst of secretion is driven by Ca2+ release from internal stores, but sustained exocytosis required external Ca2+. Data were compared to exocytosis evoked by a maximal concentration of the strong secretagogue ionomycin (1 microM), for which there was a delay between calcium elevation and secretion of 1.67+/-0.24 s (n=6), and a peak fusion rate of approximately 10 WPB s(-1).

Vestibular rehabilitation and 6-month follow-up using objective and subjective measures.

CONCLUSIONS: Vestibular rehabilitation improves quality of life by reducing the degree of handicap, improving the ability to perform everyday tasks and providing long-term rehabilitation stability (at 6 months). Recovery of the vestibulo-ocular reflex and the vestibulo-spinal reflex efficiency was proven by the objective results obtained in this study. Vestibular rehabilitation improves both subjective and objective parameters, although no significant correlation between these two indices was found. OBJECTIVE: To determine the outcome of subjective and objective parameters and long-term rehabilitation stability after vestibular rehabilitation in 43 patients with vestibular disorders. MATERIAL AND METHODS: The subjective tests used were the Medical Outcomes Study 36-item Short Form, the Dizziness Handicap Inventory and the Activity-specific Balance Confidence scale. The objective tests used were video-oculoscopy, dynamic visual acuity, the Equitest and the Dynamic Gait Index. All indices were evaluated before and after rehabilitation and at follow-up. RESULTS: All patients showed an improvement in quality of life and a reduction in handicap due to dizziness. Improvement in objective test results was also seen. These results were stable at follow-up. A correlation was found between different subjective measures, but there was no correlation between subjective and objective measures.

Xanthones from Garcinia smeathmannii (Oliver) and their antimicrobial activity.

Two new xanthones, smeathxanthone A (1) (2-(3,7-dimethyl-2,6-octadienyl)-1,3,5,8-tetrahydroxyxanthone) and smeathxanthone B (2) (5,7,10-trihydroxy-2-methyl-2-(4-methylpent-3-enyl)[2H, 6H]pyrano[3,2-b]xanthen-6-one), have been isolated from the stem bark of Garcinia smeathmannii, and their structures elucidated on the basis of 1D and 2D NMR experiments. 1,3,5-Trihydroxyxanthone and 1,5-dihydroxyxanthone were also obtained. The compounds showed only modest activity against a range of bacteria and yeasts.

Standardization of the comet assay technique on FRTL5 cells.

The comet assay is a sensitive and rapid method for DNA strand break detection in individual cells. The principle of break detection, using either the alkaline or neutral version of the assay, makes it a good technique for studying both double and single strand DNA breaks. Furthermore, the possibility of following DNA damage at different time moments also makes it possible to investigate the cell repair mechanisms. This explains why in the last few years there has been a tremendous increase in the number of laboratories which started to use this technique. The technique was first created for lymphocyte cells and later on has been used on many other cell types, growing both in suspension and adherent. To date, no one has applied this technique on normal differentiated endocrine cells, such as FRTL5 cells (Fisher Rat Thyroid Cells). The aim of this study has been to standardize the alkaline version of the Comet Assay technique on FRTL5 cells by studying the kinetics of DNA-damage and DNA-repair after different doses of UV-C (254 nm). FRTL-5 cells not only resulted very sensitive to UV-C (p<0.05 at 5 J/m2), but were also able to repair most of their DNA damage very rapidly (within one hour) as shown by a significant exponential regression in comet length. Finally, the successful measurement of biomarkers of UV-C on thyroid cells established the comet assay as a valuable tool in measurement of DNA damage and repair. Any radiation, or other damaging agents, interacting with living organisms could cause DNA damages which, depending upon dosages and kinetics of exposure, may or may not be completely repaired.

Radiation-dependent apoptosis on cultured thyroid cells.

Aim of this investigation is the study of the modifications and the DNA damage occurring in thyroid cells exposed to radiation. The FRTL-5 rat thyroid cell strain has been chosen for this study. Objects of this research are both Ionizing radiation, of fundamental interest for space missions, and the UV radiation, (also mutagen and frequent cause of several cancer forms). The present study of UV radiation represents a preliminarily tool to investigate the biological radiation damage. FRTL-5 cells have been irradiated with doses of UV-C (254 nm wavelength) ranging from 15 to 80 Joule/m2. The DNA damage has been analyzed with the 'DNA ladder by gel electrophoresis' technique. DNA has been extracted at 24 and 48 hours from irradiation. At 24h the apoptotic process is not detectable. At 48 h from irradiation, cells show the characteristic signs of apoptosis. The lower dose to which the apoptotic process is detectable, corresponds to 20 Joule/m2. At the higher doses a bigger percentage of cells undergoes apoptosis. These data confirms that the FRTL-5 biological system is particularly suitable for further studies on the biological mechanisms of radiation damage.

New isoflavones from Ceiba pentandra.

Two new isoflavones, pentandrin (1) and pentandrin glucoside (2), were isolated from the stem barks of Ceiba pentandra along with beta-sitosterol and its 3-O-beta-D-glucopyranoside, which was isolated for the first time from this plant. The structures of these compounds were elucidated with the help of spectroscopic techniques, while the structure of 1 was unambiguously confirmed by single-crystal X-ray diffraction studies.

Response to thyrotropin of normal thyroid follicular cell strain FRTL5 in hypergravity.

Thyroid hormones control every cell in the organisms and, as indicated by many hormonal changes in astronauts during and shortly after space missions, its complex regulation may be influenced by gravity. To test in vitro the effects of gravity environment on thyroid, we selected a unique cultured cell system: the FRTL5, a normal follicular thyroid cell strain in continuous culture, originally derived from adult rat thyroids. To establish if modifications of the gravitational environment may interfere with post-receptorial signal transduction mechanisms in normal mammalian cultured cells, following our previous microgravity experiments, we exposed thyrotropin-stimulated and unstimulated FRTL5 cells to hypergravity (5 g and 9 g) in a special low-speed centrifuge. At all thyrotropin doses tested, we found significant increases in terms of cyclic AMP production in FRTL5 thyroid cells. The data here reported correlate well with our previous microgravity data, showing that the FRTL5 cells functionally respond to the variable gravity force in a dose-dependent manner in terms of cAMP production following TSH-stimulation.

In vitro cultured cells as probes for space radiation effects on biological systems.

Near future scenarios of long-term and far-reaching manned space missions, require more extensive knowledge of all possible biological consequences of space radiation, particularly in humans, on both a long-term and a short-term basis. In vitro cultured cells have significantly contributed to the tremendous advancement of biomedical research. It is therefore to be expected that simple biological systems such as cultured cells, will contribute to space biomedical sciences. Space represents a novel environment, to which life has not been previously exposed. Both microgravity and space radiation are the two relevant components of such an environment, but biological adaptive mechanisms and efficient countermeasures can significantly minimize microgravity effects. On the other hand, it is felt that space radiation risks may be more relevant and that defensive strategies can only stem from our deeper knowledge of biological effects and of cellular repair mechanisms. Cultured cells may play a key role in such studies. Particularly, thyroid cells may be relevant because of the exquisite sensitivity of the thyroid gland to radiation. In addition, a clone of differentiated, normal thyroid follicular cells (FRTL5 cells) is available in culture, which is well characterized and particularly fit for space research.

Response to hypogravity of normal in vitro cultured follicular cells from thyroid.

Aim of this investigation is the study of molecular modifications occurring in differentiated mammalian cells exposed to gravitational changes. The test system chosen is a well characterized clone of differentiated, normal thyroid follicular cells (FRTL5) in long-term culture. As a follow-up to our recent experiment performed during the MASER-7 sounding rocket mission, flown for European Space Agency by Swedish Space Corporation in May 1996, we evaluated FRTL5 cells responses to Thyroid Stimulating Hormone dependent cAMP production under acute hypogravity conditions obtained in a fast rotating clinostat. Following this approach, we evaluated the FRTL5 cells response to TSH under microgravity conditions in order to optimize experimental tools and strategies in preparation to, and in between real flight missions.