ORCID Profile
0000-0001-6208-3313
Current Organisation
University of Tasmania
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Publisher: American Physiological Society
Date: 03-2020
DOI: 10.1152/AJPLUNG.00492.2019
Abstract: Both overdistension and atelectasis contribute to lung injury and mortality during mechanical ventilation. It has been proposed that combinations of tidal volume and end-expiratory lung volume exist that minimize lung injury linked to mechanical ventilation. The aim of this study was to examine this at the regional level in the healthy and endotoxemic lung. Adult female BALB/c mice were injected intraperitoneally with 10 mg/kg lipopolysaccharide (LPS) in saline or with saline alone. Four hours later, mice were mechanically ventilated for 2 h. Regional specific end-expiratory volume (sEEV) and tidal volume (sVt) were measured at baseline and after 2 h of ventilation using dynamic high-resolution four-dimensional computed tomography images. The regional expression of inflammatory genes was quantified by quantitative PCR. There was a heterogenous response in regional sEEV whereby endotoxemia increased gas trapping at end-expiration in some lung regions. Within the healthy group, there was a relationship between sEEV, sVt, and the expression of Tnfa, where high Vt in combination with high EEV or very low EEV was associated with an increase in gene expression. In endotoxemia there was an association between low sEEV, particularly when this was combined with moderate sVt, and high expression of IL6. Our data suggest that preexisting systemic inflammation modifies the relationship between regional lung volumes and inflammation and that although optimum EEV-Vt combinations to minimize injury exist, further studies are required to identify the critical inflammatory mediators to assess and the effect of different injury types on the response.
Publisher: American Society for Microbiology
Date: 2015
DOI: 10.1128/JCM.02029-14
Abstract: The etiology of an outbreak of gastroenteritis in humans cannot always be determined, and ∼25% of outbreaks remain unsolved in New Zealand. It is hypothesized that novel viruses may account for a proportion of unsolved cases, and new unbiased high-throughput sequencing methods hold promise for their detection. Analysis of the fecal metagenome can reveal the presence of viruses, bacteria, and parasites which may have evaded routine diagnostic testing. Thirty-one fecal s les from 26 gastroenteritis outbreaks of unknown etiology occurring in New Zealand between 2011 and 2012 were selected for de novo metagenomic analysis. A total data set of 193 million sequence reads of 150 bp in length was produced on an Illumina MiSeq. The metagenomic data set was searched for virus and parasite sequences, with no evidence of novel pathogens found. Eight viruses and one parasite were detected, each already known to be associated with gastroenteritis, including adenovirus, rotavirus, sapovirus, and Dientamoeba fragilis . In addition, we also describe the first detection of human parechovirus 3 (HPeV3) in Australasia. Metagenomics may thus provide a useful audit tool when applied retrospectively to determine where routine diagnostic processes may have failed to detect a pathogen.
Publisher: American Physiological Society
Date: 10-2020
DOI: 10.1152/JAPPLPHYSIOL.00097.2020
Abstract: This study provides novel insights into the regional response to mechanical ventilation in the setting of acid-induced lung injury and highlights the complex interaction between tidal stretch and low end-expiratory lung volumes both of which caused altered regulation of different injury pathways.
Publisher: Springer Science and Business Media LLC
Date: 25-11-2009
Publisher: Springer Science and Business Media LLC
Date: 25-10-2007
Abstract: Malaria diagnosis is vital to efficient control programmes and the recent advent of malaria rapid diagnostic tests (RDTs) provides a reliable and simple diagnostic method. However a characterization of the efficiency of these tests and the proteins they detect is needed to maximize RDT sensitivity. Plasmodial lactate dehydrogenase ( pLDH ) gene of wild isolates of the four human species of Plasmodium from a variety of malaria endemic settings were sequenced and analysed. No variation in nucleotide was found within Plasmodium falciparum , synonymous mutations were found for Plasmodium malariae and Plasmodium. vivax and three different types of amino acid sequence were found for Plasmodium ovale . Conserved and variable regions were identified within each species. The results indicate that antigen variability is unlikely to explain variability in performance of RDTs detecting pLDH from cases of P. falciparum, P. vivax or P. malariae malaria, but may contribute to poor detection of P. ovale .
Publisher: International Union Against Tuberculosis and Lung Disease
Date: 07-2013
Abstract: In New Zealand, the lineage genotypes of Mycobacterium tuberculosis clinical isolates and their role in the epidemiology of tuberculosis (TB) are currently unknown. 1) To measure the relative frequency of each phylogenetic lineage of the M. tuberculosis complex in New Zealand, and 2) to examine its relationship with patient demographics and multidrug-resistant TB (MDR-TB). All non-duplicate M. tuberculosis complex isolates recovered in 2010 and 2011 underwent large sequence polymorphism and/or single nucleotide polymorphism analyses. Mycobacterial interspersed repetitive units (MIRU) profiling was also performed for cluster identification. New Zealand isolates were dominated by lineage 4 (Euro-American: 37.8%, 95%CI 33.6-42.2), followed by lineage 1 (Indo-Oceanic: 22.6%, 95%CI 19.1-26.5), lineage 2 (East Asian: 19.5%, 95%CI 16.2-23.3) and lineage 3 (East-African Indian, which included Central Asian: 17.7%, 95%CI 14.5-21.3). Lineage 2 accounted for 58.1% of MDR-TB cases from 2002 to 2011. Among immigrants, the predominant lineages corresponded to high prevalence lineages in the country of origin. In New Zealand-born in iduals, Māori and NZ Europeans share the same predominant lineage, lineage 4, with a higher proportion of non-unique MIRU types observed in Māori cases. Lineage 3 was more prevalent in Māori than in NZ Europeans. In New Zealand, M. tuberculosis complex phylogenetic lineage is associated with TB epidemiology in terms of ethnicity, country of origin and MDR-TB.
Publisher: American Thoracic Society
Date: 05-2019
Location: New Zealand
No related grants have been discovered for Seiha Yen.