Summary
Blastocystis is an enteric parasite that causes acute and chronic intestinal infections, often non‐responsive to conventional antibiotics. The effects of Blastocystis infections on human ...epithelial permeability are not known, and molecular mechanisms of Blastocystis‐induced intestinal pathology remain unclear. This study was conducted to determine whether Blastocystis species alters human intestinal epithelial permeability, to assess whether these abnormalities are rho kinase (ROCK)‐dependent, and to investigate the therapeutic potential of the HMG‐CoA reductase inhibitor Simvastatin in altered intestinal epithelial barrier function. The effect of metronidazole resistant (Mzr) Blastocystis isolated from a symptomatic patient on human colonic epithelial monolayers (Caco‐2) was assessed. Modulation of enterocyte myosin light chain phosphorylation, transepithelial fluorescein isothiocyanate‐dextran fluxes, transepithelial resistance, cytoskeletal F‐actin and tight junctional zonula occludens‐1 (ZO‐1) by parasite cysteine proteases were measured in the presence or absence of HMG‐CoA reductase and ROCK inhibition. Blastocystis significantly decreased transepithelial resistance, increased epithelial permeability, phosphorylated myosin light chain and reorganized epithelial actin cytoskeleton andZO‐1. Thesealterations were abolished byinhibition of enterocyte ROCK, HMG‐CoA reductase and parasite cysteine protease. Our findings suggest that cysteine proteases of Mzr Blastocystis induce ROCK‐dependent disruption of intestinal epithelial barrier function and correlates with reorganization of cytoskeletal F‐actin and tight junctional ZO‐1. Simvastatin prevented parasite‐induced barriercompromise, suggesting a therapeutic potential of statins in intestinal infections.
Blastocystis spp. is a common enteric stramenopile parasite that colonizes the colon of hosts of a diverse array of species, including humans. It has been shown to compromise intestinal epithelial ...cell barrier integrity and mediate the production of pro-inflammatory cytokines and chemokines. Mucosal epithelial surfaces, including the intestinal epithelium, are increasingly recognized to perform a vital surveillance role in the context of innate immunity, through the expression of pathogen recognition receptors, such as Toll-like receptors (TLRs). In this study, we use the human TLR reporter monocytic cell line, THP1-Blue, which expresses all human TLRs, to investigate effects of Blastocystis on TLR activation, more specifically the activation of TLR-2, -4 and -5. We have observed that live Blastocystis spp. parasites and whole cell lysate (WCL) alone do not activate TLRs in THP1-Blue. Live ST4-WR1 parasites inhibited LPS-mediated NF-κB activation in THP1-Blue. In contrast, ST7-B WCL and ST4-WR1 WCL induced pleiotropic modulation of ligand-specific TLR-2 and TLR-4 activation, with no significant effects on flagellin-mediated TLR-5 activation. Real time-qPCR analysis on SEAP reporter gene confirmed the augmenting effect of ST7-B on LPS-mediated NF-κB activation in THP1-Blue. Taken together, this is the first study to characterize interactions between Blastocystis spp. and host TLR activation using an in vitro reporter model.
Blastocystis
is an enteric protistan parasite of uncertain clinical relevance. Recent studies indicate that the parasite is a species complex and humans are potentially hosts to nine
Blastocystis
...subtypes, most of which are zoonotic. Subtype 3 is the most common in prevalence studies, followed by subtype 1. Laboratory diagnosis is challenging; the currently recommended diagnostic approach is trichrome staining of direct smears coupled with stool culture. Polymerase chain reaction testing from stools or culture is useful for determining
Blastocystis
subtype information. The controversial pathogenesis of
Blastocystis
is attributed to subtype variations in virulence; although current studies seem to support this idea, evidence suggests other factors also contribute to the clinical outcome of the infection. Clinical signs and symptoms of blastocystosis include abdominal pain, diarrhea, bloating, and flatulence. Extraintestinal manifestations, predominantly cutaneous, also were reported. In vitro and animal studies shed new light on the pathobiology of
Blastocystis
.
Blastocystis is an emerging protistan parasite colonizing the human intestine. It is frequently reported to cause general intestinal symptoms of vomiting, diarrhea, and abdominal pain. We recently ...demonstrated that Blastocystis rearranged cytoskeletal proteins and induced intestinal epithelial barrier compromise. The effect of Blastocystis on enterocyte apoptosis is unknown, and a possible link between microbially induced enterocyte apoptosis and increased epithelial permeability has yet to be determined. The aim of this study is to assess if Blastocystis induces human enterocyte apoptosis and whether this effect influences human intestinal epithelial barrier function. Monolayers of polarized human colonic epithelial cell-line Caco-2 were incubated with Blastocystis subtype 7 and subtype 4. Assays for both early and late markers of apoptosis, phosphatidylserine externalization, and nuclear fragmentation, respectively, showed that Blastocystis ST-7, but not ST-4, significantly increased apoptosis in enterocytes, suggesting that Blastocystis exhibits host specificity and strain-to-strain variation in pathogenicity. ST-7 also activated Caco-2 caspases 3 and 9 but not 8. ST-7 induced changes in epithelial resistance, permeability, and tight junction (ZO-1) localization. Pretreatment of Caco-2 monolayers with a pan-caspase inhibitor z-VAD-fmk significantly inhibited these changes. This suggests a role for enterocyte apoptosis in Blastocystis-mediated epithelial barrier compromise in the human intestine.
Bermuda grass latent virus (BGLV; genus
Panicovirus
) is identified for the first time in Australia and in only the second country after the USA. A full-length genome sequence was obtained, which has ...97% nucleotide sequence identity to that of the species exemplar isolate. Surveys for BGLV, utilising a newly designed universal panicovirus RT-PCR assay for diagnosis, demonstrated widespread infection by this virus in a broad variety of Bermuda grass cultivars (
Cynodon dactylon
and
C. dactylon
×
C. transvaalensis
) grown in both New South Wales and Queensland. The virus was also detected in Rhodes grass (
Chloris gayana
) and Kikuyu grass (
Cenchrus clandestinus
), which are both important pasture grasses in subtropical Australia, and the latter is also grown as turf. Furthermore, the Rhodes grass plant, which had strong mosaic symptoms, was also infected with sugarcane mosaic virus, warranting further investigations as to whether synergistic interactions occur between these two viruses.
The comparability of endovascular coiling over neurosurgical clipping has not been firmly established in elderly patients with aneurysmal subarachnoid haemorrhage (aSAH). Data were obtained from all ...patients with aSAH aged ≥60 across three tertiary hospitals in Singapore from 2014 to 2019. Outcome measures included modified Rankin Scale (mRS) score at 3 and at 6 months, and in-hospital mortality. Of the 134 patients analyzed, 84 (62.7%) underwent coiling and 50 (37.3%) underwent clipping. The endovascular group showed a higher incidence of good mRS score 0–2 at 3 months (OR = 2.45 95%CI:1.16–5.20;
p
= 0.018), and a lower incidence of in-hospital mortality (OR = 0.31 95%CI:0.10–0.91;
p
= 0.026). There were no significant difference between the two treatment groups in terms of good mRS score at 6 months (OR = 1.98 95%CI:0.97–4.04;
p
= 0.060). There were no significant differences in the incidence of complications, such as aneurysm rebleed, delayed hydrocephalus, delayed ischemic neurological deficit and venous thromboembolism between the two treatment groups. However, fewer patients in the coiling group developed large infarcts requiring decompressive craniectomy (OR = 0.32 95%CI:0.12–0.90;
p
= 0.025). Age, admission WFNS score I–III, and coiling were independent predictors of good functional outcomes at 3 months. Only age and admission WFNS score I–III remained significant predictors of good functional outcomes at 6 months. Endovascular coiling, compared with neurosurgical clipping, is associated with significantly better short term outcomes in carefully selected elderly patients with aSAH. Maximal intervention is recommended for aSAH in the young elderly age group and those with favorable WFNS scores.
Full genome sequences are presented for two isolates of Spartina mottle virus (SpMoV) from two accessions of the hybrid turf grass Cynodon dactylon × C. transvaalensis (Bermuda grass, green couch), ...originally from the USA but detected during post‐entry quarantine in Australia. Both isolates had a genome of 9,346 nucleotides, encoding a single polyprotein of 3,029 amino acids and predicted to be cleaved into 10 mature proteins. Phylogenetic analysis strongly supported placement in a new genus within the family Potyviridae. The isolates possess 715–780 × 11–12 nm flexuous virions and produce cylindrical (pinwheel) inclusions in infected cells. They were mechanically transmitted to several species in the Poaceae including Zea mays (maize, sweet corn), Chloris gayana (Rhodes grass), and Echinochloa colona (awnless barnyard grass).
Two isolates of Spartina mottle virus from Cynodon dactylon × Cynodon transvaalensis (Bermuda grass) are characterized and full genome sequences presented, supporting placement of the virus in a new genus in the family Potyviridae.
Summary
Here, we present a case of mass ventilator failure due to contaminated medical air. Multiple ventilators failed routine tests, including almost all of the ventilators in our intensive care ...unit. A faulty air compressor had led to water contamination of our centre's supply of medical air. Water entered the pipeline supply of air and, hence the ventilators and anaesthetic machines. The disruption of the machines' proportional mixer valve resulted in unreliable delivery of fresh gas flow. This malfunction was discovered during routine pre‐use checks, and backup ventilators were available to replace the faulty ventilators. A shortage of equipment was averted due to a serendipitous availability of ventilator stockpiles prepared for the COVID‐19 pandemic. Ventilator shortages are commonly described in mass casualty and pandemic scenarios. While there are multiple strategies described in literature to augment and maximise equipment available for mechanical ventilation, stockpiling equipment remains an expensive but necessary component of disaster contingency planning.
We demonstrate that when, and only when, the biaxial stress is increased above a critical value of 6+/-1 GPa during the growth of a carbon film at room temperature, tetrahedral amorphous carbon is ...formed. This confirms that the stress present during the formation of an amorphous carbon film determines its sp;{3} bonding fraction. In the vicinity of the critical stress, a highly oriented graphitelike material is formed which exhibits low electrical resistance and provides Ohmic contacts to silicon. Atomistic simulations reveal that the structural transitions are thermodynamically driven and not the result of dynamical effects.
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