Evaluation of an automatic gas chromatographic system for the identification of bacterial infective agents

The potential clinical application of gas chromatography to microbial identifcation was evaluated. A completely automated system, the MIS (Microbial Identification System; Hewlett- Packard) can analyse and identify pure strains by comparison of their cellular fatty acids patterns (C9-C20) with the reference parameters stored in a library. Three hundred and sixty-seven strains were tested, comparing the gas chromatographic results with those obtained by the traditional microbiological methods in the bacteriology laboratory of our Institute. A standardized extractive procedure was followed to obtain the fatty acid methyl esters (FAMEs), but some modifications to the recommended procedure were introduced in the bacterial growth procedures: colonies harvested not only from the recommended growth media but also from selective media routinely used in the bacteriology laboratory were successfully examined. These modifications did not influence the results but improved the ease for the user; good agreement with the comparison method was observed as far as identifications of genus and species are concerned for 238 cases. The major advantages of this computerized system are a reduction in the time required to obtain the final results, the elimination of human errors by using the autosampler and a better inter-laboratory comparability of results owing to a higher degree of objectivity. On the other hand, the limited throughput of MIS (only 40 samples in 24 h) prevents its use in a large routine laboratory; this technology is appropriate in emergency cases, in taxonomic studies and as a confirmatory method

Tocilizumab Effects on Coagulation Factor XIII in Patients with Rheumatoid Arthritis

Introduction: Rheumatoid arthritis (RA) is a chronic systemic auto-immune disease associated with a prothrombotic state. Tocilizumab, an interleukin-6 receptor inhibitor, is highly effective in controlling disease activity and thrombotic risk. Factor XIII (FXIII), involved in thrombotic complications, has been reported to be reduced in RA patients during maintenance treatment with tocilizumab, but no data are available before and after the drug administration. Thus, we investigated the effects of tocilizumab on FXIII, thrombin generation and inflammation in patients with RA na\uefve for the drug. Methods: We studied 15 consecutive adult patients with RA at baseline and 4 weeks after the onset of parenteral administration of tocilizumab, measuring disease activity and plasma levels of C-reactive protein (CRP), FXIII, and prothrombin fragments F1+2 by immunoenzymatic methods. Fifteen healthy subjects, sex-and age-matched with patients, served as normal controls for laboratory measurements. Results: At baseline, patients with established RA had a median DAS28 of 4.8 (3.2\u20138.3) and, compared to healthy controls, had higher plasma levels of CRP (p < 0.0001), FXIII (p = 0.017) and F1+2 (p < 0.0001). Four weeks after starting treatment with tocilizumab, based on the EULAR response criteria, eight patients were classifiable as responders and seven as non-responders. In responders, we observed a statistically significant reduction not only of the values of DAS28 and CRP (p = 0.012 for both), ut also of plasma levels of FXIII (p = 0.05) and F1+2 (p = 0.025). In non-responders, all the studied parameters were unchanged. Conclusion: The decrease of FXIII and F1+2 levels after tocilizumab treatment observed only in those patients who responded to the drug indicates that the effect of tocilizumab on the prothrombotic state is linked to the control of inflammation and disease activity and not to a direct effect of the drug, thus contributing to the reduction of the cardiovascular risk

Development of a One-Dimensional Model for the Prediction of Leakage Flows in Regenerative Pumps

Regenerative pumps are characterized by a low specific speed that place them between rotary positive displacement pumps and purely radial centrifugal pumps. They are interesting for many industrial applications since, for a given flow rate and a specified head, they allow for a reduced size and can operate at a lower rotational speed with respect to purely radial pumps. The complexity of the flow within regenerative machines makes the theoretical performance estimation a challenging task. The prediction of the leakage flow rate between the rotating and the static disks is the one that more than others has an impact on the prediction of global performance. All the classical approaches to the disk clearance problem assume that there is no relevant circumferential pressure gradient. In the present case, the flow develops along the tangential direction and the pressure gradient is intrinsically non-zero. The aim of the present work is to develop a reliable approach for the prediction of leakage flows in regenerative pumps. The method assumes that the flow inside of the disk clearance can be decomposed into several stream-tubes. Energy balance is performed for each tube, thus generating a system that can be solved numerically. The new methodology has been tuned using data obtained from the numerical simulation of virtual prototypes of regenerative pumps where the disk clearance is part of the control volume. After that, the methodology has been integrated into an existing one-dimensional code called DART (developed at the University of Florence in cooperation with Pierburg Pump Technology Italy S.p.A.) and the new algorithm is verified using available experimental and numerical data. It is here demonstrated that an appropriate calibration of the leakage flow model allows for an improved reliability of the one-dimensional code

Selective blockade of mglu5 metabotropic glutamate receptors is protective against acetaminophen hepatotoxicity in mice

BACKGROUND/AIMS: mGlu5 metabotropic glutamate receptor antagonists protect rat hepatocytes against hypoxic death. Here, we have examined whether mGlu5 receptor antagonists are protective against liver damage induced by oxidative stress. METHODS: Toxicity of isolated hepatocytes was induced by tert-butylhydroperoxide (t-BuOOH) after pretreatment with the mGlu5 receptor antagonists, MPEP, SIB-1757 and SIB-1893. The effect of these drugs was also examined in mice challenged with toxic doses of acetaminophen. RESULTS: Addition of tBuOOH (0.5 mM) to isolated hepatocytes induced cell death (70+/-5% at 3 h). Addition of MPEP or SIB-1893 to hepatocytes reduced both the production of reactive oxygen species (ROS) and cell toxicity induced by t-BuOOH (tBuOOH=70+/-5%; tBuOOH+MPEP=57+/-6%; tBuOOH+SIB-1893=40+/-4%). In mice, a single injection of acetaminophen (300 mg/kg, i.p.) induced centrilobular liver necrosis, which was detectable after 24 h. MPEP (20 mg/kg, i.p.) substantially reduced liver necrosis and the production of ROS, although it did not affect the conversion of acetaminophen into the toxic metabolite, N-acetylbenzoquinoneimine. MPEP, SIB-1893 and SIB-1757 (all at 20 mg/kg, i.p.) also reduced the increased expression and activity of liver iNOS induced by acetaminophen. CONCLUSIONS: We conclude that pharmacological blockade of mGlu5 receptors might represent a novel target for the treatment of drug-induced liver damage

Revealing structural evolution occurring from photo-initiated polymer network formation

Acomplete account of the structural evolution occurring during photopolymerisation is lacking. Here the physical changes occurring on the nanometer scale during photopolymerisation of acrylates are followed over time by FTIR, X-ray reflectometry, AFM, and GISAXS, offering insight into the mechanism by which initial composition influences the final morphology

A Nanoparticle Approach towards Morphology Controlled Organic Photovoltaics (OPV)

polymer

Breast adenocarcinoma liver metastases, in contrast to colorectal cancer liver metastases, display a non-angiogenic growth pattern that preserves the stroma and lacks hypoxia

Although angiogenesis is a prerequisite for the growth of most human solid tumours, alternative mechanisms of vascularisation can be adopted. We have previously described a non-angiogenic growth pattern in liver metastases of colorectal adenocarcinomas (CRC) in which tumour cells replace hepatocytes at the tumour-liver interface, preserving the liver architecture and co-opting the sinusoidal blood vessels. The aim of this study was to determine whether this replacement pattern occurs during liver metastasis of breast adenocarcinomas (BC) and whether the lack of an angiogenic switch in such metastases is due to the absence of hypoxia and subsequent vascular fibrinogen leakage. The growth pattern of 45 BC liver metastases and 28 CRC liver metastases (73 consecutive patients) was assessed on haematoxylin- and eosin-stained tissue sections. The majority of the BC liver metastases had a replacement growth pattern (96%), in contrast to only 32% of the CRC metastases (P<0.0001). The median carbonic anhydrase 9 (CA9) expression (M75 antibody), as a marker of hypoxia, (intensity x % of stained tumour cells) was 0 in the BC metastases and 53 in the CRC metastases (P<0.0001). There was CA9 expression at the tumour-liver interface in only 16% of the BC liver metastases vs 54% of the CRC metastases (P=0.002). There was fibrin (T2G1 antibody) at the tumour-liver interface in only 21% of the BC metastases vs 56% of the CRC metastases (P=0.04). The median macrophage count (Chalkley morphometry; KP-1 anti-CD68 antibody) at the interface was 4.3 and 7.5, respectively (P<0.0001). Carbonic anhydrase 9 score and macrophage count were positively correlated (r=0.42; P=0.002) in all metastases. Glandular differentiation was less in the BC liver metastases: 80% had less than 10% gland formation vs only 7% of the CRC metastases (P<0.0001). The liver is a densely vascularised organ and can host metastases that exploit this environment by replacing the hepatocytes and co-opting the vasculature. Our findings confirm that a non-angiogenic pattern of liver metastasis indeed occurs in BC, that this pattern of replacement growth is even more prevalent than in CRC, and that the process induces neither hypoxia nor vascular leakage

Opeatogenys gracilis (Pisces: Gobiesocidae): An overlooked species or another ‘Mediterranean endemism’ found in Atlantic waters?

The occurrence of Opeatogenys gracilis outside the Mediterranean Sea is confirmed for the first time. This is probably a more common species than previously thought, but its apparent complete dependence on seagrass beds suggests the possibility of including it in the IUCN threatened species list. Some sex differences are described and a complete meristic and morphometric description of the species is presented. The occurrence of the species in the north-east Atlantic indicates that it might be a recent dispersal from the Mediterranean Sea, or an overlooked part of the autochthonous fauna