Identification of novel porcine and bovine parvoviruses closely related to human parvovirus 4

Human parvovirus 4 (PARV4), a recently discovered parvovirus found exclusively in human plasma and liver tissue, was considered phylogenetically distinct from other parvoviruses. Here, we report the discovery of two novel parvoviruses closely related to PARV4, porcine hokovirus (PHoV) and bovine hokovirus (BHoV), from porcine and bovine samples in Hong Kong. Their nearly full-length sequences were also analysed. PARV4-like viruses were detected by PCR among 44.4% (148/333) of porcine samples (including lymph nodes, liver, serum, nasopharyngeal and faecal samples), 13% (4/32) of bovine spleen samples and 2% (7/362) of human serum samples that were sent for human immunodeficiency virus and hepatitis C virus antibody tests. Three distinct parvoviruses were identified, including two novel parvoviruses, PHoV and BHoV, from porcine and bovine samples and PARV4 from humans, respectively. Analysis of genome pequences from seven PHoV strains, from three BHoV strains and from one PARV4 strain showed that the two animal parvoviruses were most similar to PARV4 with 61.5-63% nt identities and, together with PARV4 (HHoV), formed a distinct cluster within the family Parvoviridae. The three parvoviruses also differed from other parvoviruses by their relatively large predicted VP1 protein and the presence of a small unique conserved putative protein. Based on these results, we propose a separate genus, Hokovirus, to describe these three parvoviruses. The co-detection of porcine reproductive and respiratory syndrome virus, the agent associated with the recent 'high fever' disease outbreaks in pigs in China, from our porcine samples warrants further investigation. © 2008 SGM.published_or_final_versio

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

Background Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications. Methods We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC). Findings In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683–0·717]). Interpretation In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required. Funding British Journal of Surgery Society

Specific labelling of sulfhydryl-containing biomolecules with redox-active N-(ferrocenyl)iodoacetamide

The synthesis, characterisation, X-ray crystal structure and electrochemical properties of a new redox-active labelling reagent, N-(ferrocenyl)iodoacetamide (Fc-IAA), are reported. This compound exhibits a reversible ferrocenium/ferrocene couple at ca. +0.345 V vs. SCE at a sweep rate of 100 mV s-1 in CH3CN at 298 K, and two irreversible reduction waves at ca. -1.324 and -2.048 V, attributable to the reduction of the iodoacetamide group. Since the iodoacetamide moiety can react specifically with the sulfhydryl group, Fc-IAA has been coupled to various biomolecules including a sulfhydryl-modified oligonucleotide, cysteine, glutathione and sulfhydryl-modified bovine serum albumin. The electrochemical properties of the bioconjugates have also been investigated.link_to_subscribed_fulltex

Derivatisation of microcystin with a redox-active label for high-performance liquid chromatography/electrochemical detection

Microcystins are a group of low molecular weight, cyclic peptide hepatotoxins. The most common detection and quantitation methods for these toxins are liquid chromatography with UV or mass spectrometric detections, phosphatase inhibition assays and enzyme-linked immunosorbent assays. In addition, derivatisation of these toxins with organic fluorophores followed by CE/laser induced fluorescence detection and HPLC/chemiluminescence detection; and with luminescent lanthanide chelates for competition assays have also been reported. However, the use of an electrochemical-active unit as a tag for microcystins has never been explored. Since the sulfhydryl group of 6-ferrocenylhexanethiol (Fc-C6-SH) can undergo a facile addition reaction with the α,β-unsaturated carbonyl group, this compound has been used as a redox-active labelling agent for a derivative of microcystins, microcystin-LR (MC-LR). The conjugate, Fc-MC-LR, has been isolated by high-performance liquid chromatography with electrochemical detection. The peak height-concentration curve was linear in the test range 20-400 ng of MC-LR (r value for linear regression > 0.9987). The detection limit was determined to be ca. 18 ng MC-LR (S/N ≈ 3). Meanwhile, the conjugate Fc-MC-LR has also been characterised by positive-ion electrospray-ionisation mass spectrometry. Electrochemical studies show that the adduct displays a reversible ferrocenium/ferrocene couple at ca. -0.040 V vs. SCE (scan rate = 50 mV s-1) in 0.1 M aqueous ammonium acetate-acetonitrile (55:45 v/v).link_to_subscribed_fulltex

Health care provider's experience and perspective of cervical cancer screening in Singapore: A qualitative study

10.3389/fpubh.2022.853453Frontiers in Public Health10853453

Non-covalent Binding of Luminescent Transition Metal Polypyridine Complexes to Avidin, Iodole-binding Proteins and Estrogen Receptors

A number of luminescent transition metal complexes possess rich photophysical and photochemical properties that allow them to serve as useful labels and probes for biological molecules. This article describes the current trend in this area of research, with emphasis on our recent work on luminescent rhenium(I), iridium(III) and ruthenium(II) polypyridine complexes as non-covalent probes for avidin, indole-binding proteins and estrogen receptors. We focus on the molecular design, photophysical properties and biomolecule-binding behaviour of these systems; different approaches to enhancing the detection sensitivity are also discussed