Molybdenum(0) tricarbonyl and tetracarbonyl complexes with a cationic pyrazolylpyridine ligand: synthesis,crystal structures and catalytic performance in olefin epoxidation

The synthesis of molybdenum(0) tricarbonyl and tetracarbonyl complexes of the form [Mo(CO)₃(ptapzpy)Br] (1) and cis-[Mo(CO)₄(ptapzpy)]Br (2) is reported, where ptapzpy = 2-(1-propyltrimethylammonium-3-pyrazolyl)pyridine. Preparation of these derivatives was accomplished either through thermal replacement of CO in Mo(CO)₆ (for 1) or substitution under milder conditions of piperidine ligands in the precursor cis-[Mo(CO)₄(pip)₂] (for 2). The crystal structures of the ligand [ptapzpy]Br and complexes 1 and 2 were determined. Thermal treatment of 2 at 125–150 °C leads to mono decarbonylation and formation of 1. On the other hand, oxidative decarbonylation of 1 and 2 by reaction with tert-butylhydroperoxide (TBHP, 10 equiv.) gives a molybdenum oxide hybrid material formulated as [Mo₃O₉([ptapzpy]Br)₂]·nH₂O (3), which was characterised by FT-IR and Raman spectroscopy, thermogravimetric analysis, and ¹³C{¹H} CP MAS NMR spectroscopy. Compounds 1–3 were effective (pre)catalysts for the epoxidation of cis-cyclooctene at 55 °C with aqueous H₂O₂ or TBHP (slightly better results were obtained with the former). The characterisation of the Mo-containing solids isolated after the catalytic reaction showed that poorly soluble β-octamolybdate salts, (L)_x[Mo₈O₂₆], were formed from 1–3 with TBHP and from 1 with H₂O₂, while soluble oxoperoxo species were formed from 3 with H₂O₂. These findings helped to explain the different catalytic performances obtained.

The oxidative decarbonylation and catalytic chemistry of molybdenum(0) tricarbonyl and tetracarbonyl complexes containing the same diimine ligand are compared.     

Xenobiotic-metabolizing enzymes in plants and their role in uptake and biotransformation of veterinary drugs in the environment

Many various xenobiotics permanently enter plants and represent potential danger for their organism. For that reason, plants have evolved extremely sophisticated detoxification systems including a battery of xenobiotic-metabolizing enzymes. Some of them are similar to those in humans and animals, but there are several plant-specific ones. This review briefly introduces xenobiotic-metabolizing enzymes in plants and summarizes present information about their action toward veterinary drugs. Veterinary drugs are used worldwide to treat diseases and protect animal health. However, veterinary drugs are also unwantedly introduced into environment mostly via animal excrements, they persist in the environment for a long time and may impact on the non-target organisms. Plants are able to uptake, transform the veterinary drugs to non- or less-toxic compounds and store them in the vacuoles and cell walls. This ability may protect not only plant themselves but also other organisms, predominantly invertebrates and wild herbivores. The aim of this review is to emphasize the importance of plants in detoxification of veterinary drugs in the environment. The results of studies, which dealt with transport and biotransformation of veterinary drugs in plants, are summarized and evaluated. In conclusion, the risks and consequences of veterinary drugs in the environment and the possibilities of phytoremediation technologies are considered and future perspectives are outlined.     

Implication of different cardiac troponin I levels for clinical outcomes and prognosis of acute chest pain patients

OBJECTIVES: We compared outcomes in patients with non-ST-segment elevation acute coronary syndromes (ACS) according to the degree of cardiac troponin I (cTnI) elevation. BACKGROUND: Controlled trials of high-risk patients have found that troponin elevations identify an even higher risk subset. It is unclear whether outcomes are similar among a lower risk, heterogeneous patient group. Also, few studies have reported outcomes other than myocardial infarction (MI) or death, based on the peak troponin value. METHODS: Consecutively, admitted patients without ST-segment elevation on the initial electrocardiogram underwent serial marker sampling using creatine kinase (CK), CK-MB fraction, and cTnI. Patients were grouped according to peak cTnI: negative = no detectable cTnI; low = peak greater than the lower limit of detectability but less than the optimal diagnostic value; intermediate = peak greater than or equal to the optimal diagnostic value but less than the manufacturer's suggested upper reference limit (URL); and high = peak greater than or equal to the URL. Thirty-day outcomes included cardiac death, MI based on CK-MB, revascularization, significant disease, and a reversible defect on stress testing. Six-month mortality was also determined. Negative evaluations for ischemia included nonsignificant disease, no reversible stress defect, and negative rest perfusion imaging. RESULTS: Of the 4,123 patients admitted, 893 (22%) had detectable cTnI values. Cardiac events and positive test results at 30 days and 6-month mortality increased significantly with increasing cTnI values. Negative evaluations for ischemia were significantly and inversely related to peak cTnI values. Although adverse events were significantly more common in patients with a low cTnI value than in those with negative cTnI, negative evaluations for ischemia were frequent. CONCLUSIONS: Increased cTnI values are associated with worse outcomes. Although low cTnI values are associated with adverse events, they do not have the same implication as higher cTnI values, and nonischemic evaluations are frequent.     

Management and treatment of hepatitis C virus in patients with HIV and hepatitis C virus coinfection: A practical guide for health care professionals

Concomitant HIV and hepatitis C virus (HCV) is a common yet complex coinfection. The present document is a practical guide for treating HCV infection in people coinfected with HIV. Effective antiretroviral therapies have prolonged survival rates for HIV-infected people over the past decade, which have made latent complications of HCV major causes of morbidity and mortality in these patients. Advances in the treatment of HCV (eg, combined pegylated interferon and ribavirin) offer the possibility of eradicating HCV infection in coinfected persons. The treatment of HCV must be considered in all cases. Intensive management of the adverse effects of HCV treatment is one of the factors for the success of these therapies. HCV eradication is predicted to decrease the mortality associated with coinfection and reduce the toxicity of HIV treatment.     

Calcium-binding proteins: distribution and implication in mammalian placenta

During gestation, transport by the placenta is solely responsible for nutrient supply to the developing fetus. In this context, calcium (Ca²⁺) transport machinery of the placenta thus represents the primary tissue site for regulating fetal Ca²⁺ homeostasis. In humans, the transplacental movements of Ca²⁺ increase dramatically during the last trimester of gestation, when fetal skeletal mineralization is at its highest. However, little is known about the exact mechanism of transport. Evidence suggests that some developmentally expressed cytosolic Ca²⁺-binding proteins (CaBPs) have an important role in regulating or shuttling cytosolic Ca²⁺ since they are endowed with a high affinity for Ca²⁺ (∼10⁶ M ⁻¹). CaBPs belong to a large family of eukaryotic proteins containing a specific helix-loop-helix structure, referred to as the EF-hand motif, which counts more than 200 members. Several of these CaBPs were identified in the placenta: CaBP9k, CaBP28k, CaBP57k, oncomodulin, S-100P, S-100α, and S-100β. This review discusses the current views in this field to guide future investigations into the localization and functions of CaBPs during Ca²⁺ intracellular homeostasis in the placenta.     

Early epileptic seizures in ischaemic stroke treated by mechanical thrombectomy: influence of rt-PA

Journal of Neurology - The epileptogenicity of recombinant tissue-plasminogen activator (rt-PA) has been suggested, but seizures were not evaluated in randomised controlled trials. To evaluate...     

Genetic diversity of porcine sapoviruses, kobuviruses, and astroviruses in asymptomatic pigs: an emerging new sapovirus GIII genotype

Small, non-enveloped RNA viruses belonging to the genera Sapovirus, Kobuvirus, and Mamastrovirus are usually associated with gastroenteritis in humans and animals. These enteric pathogens are considered potential zoonotic agents. In this study, the prevalence and genetic diversity of sapoviruses (SaVs), kobuviruses (KoVs), and astroviruses (AstVs) in asymptomatic pigs were investigated using a PCR approach. KoV was found to be the most prevalent virus (87.3 %), followed by AstV (34.2 %) and SaV (10.2 %). Interestingly, the intra- and inter-cluster distances between porcine SaV capsid sequences revealed one strain (P38/11/CZ) that formed a new genotype within genogroup III of porcine SaVs, and it is tentatively called “P38/11-like” genotype. Moreover, this is the first report of porcine kobuvirus detection on Czech pig farms. The high prevalence rate of gastroenteritis-producing viruses in clinically healthy pigs represents a continuous source of infection of pigs, and possibly to humans.     

HHV-6 cell receptor CD46 expression on various cell subsets of six blood and graft sources: A prospective series

BackgroundCord Blood (CB) are increasingly used as an alternative stem cells source in adults for allogeneic Stem Cell Transplantation (allo-SCT). The risk of human herpesvirus (HHV-6) reactivation is significantly higher after CB transplant vs unrelated peripheral blood stem cells (PBSC) allo-SCT. Higher HHV-6 cell receptor CD46 expression on progenitor cells in CB may explain this difference.ObjectivesTo prospectively compare the HHV-6 cell receptor CD46 expression on various cell subsets of three freshly harvested blood sources on one hand and of three graft sources on the other hand.Study design52 samples were used for the purpose of this study. They were issued from peripheral blood (PB, n = 10), G-CSF mobilised PB (GCSF-PB, n = 10), cord blood (CB, n = 10), unmanipulated bone marrow (uBM, n = 5), leukapheresis product (LP, n = 10) and thawed CB graft (n = 7). CD46 expression was assessed by FACS analysis on total lymphocytes, monocytes, NK cells, T and B cells subsets, plasmacytoid (pDCs) dendritic cells and stem cells.ResultsAs all cell subsets were found CD46 positive, CD46 mean fluorescence intensity (MFI) was then considered for comparison between the three blood sources and the three graft sources. The most impressive result observed was that HHV-6 cell receptor CD46 expression was significantly reduced in almost all cell components of thawed CB graft compared to other graft sources.ConclusionsThis original study shows strong differences in term of quantitative CD46 expression between several blood and grafts samples. Our results suggest that other factors than the qualitative CD46 expression play a role in the higher HHV-6 reactivation observed after CB transplant in adults.     

Removal of osseointegrated dental implants: a systematic review of explantation techniques

Objectives

This systematic review aims to evaluate current literature regarding available techniques for removal of osseointegrated implants in terms of explantation’s success, complications, and bone loss.

Material and methods

Two reviewers conducted a systematic literature search through electronic databases (PubMed and EMBASE), complimented by manual and grey literature searches. Successful explantation was defined as the primary outcome. Complications and availability of residual bone for immediate implantation were defined as secondary outcomes.

Results

Eighteen articles, comprising 372 implants and 241 patients, were included. Five techniques were identified: reverse torque, trephines, burs, piezosurgery, and laser-assisted explantation. Peri-implantitis was the most common reason for explantation, followed by crestal bone loss, fracture, and malpositioning. The reverse torque was the most frequently reported technique (284 implants) with 87.7% success rate. Burs were used for explantation of 49 implants with a 100% success rate, while trephines were utilized for removal of 35 implants with 94% success. Piezosurgery (11 implants) and Er.Cr:YSGG laser (1 implant) showed 100% success. One study reported perforation of the sinus floor following trephine explantation, while another reported fracture of 3 implants following reverse torque application. Further analysis was hindered by the quality of the available studies and their lack of data.

Conclusions

Reverse torque seems the most conservative, and in the authors’ opinion, should be the first choice for explantation despite its inferior success rate. Additional studies with randomized controlled designs and larger sample sizes are required.

Clinical relevance

Dental implants have become the leading choice to replace missing teeth with gradually increasing numbers of complications and failures. An effective, conservative, and economic explantation technique is necessary to allow a successive implant placement.