Methylation of TIMP3 in esophageal squamous cell carcinoma

AIM： To measure the frequency of DNA methylation of the tissue inhibitor of metalloproteinase 3 （TIMP3） promoter and relate this to any change of gene expression in esophageal squamous cell carcinoma in patients from a region of high incidence in China. METHODS： Cancer cell lines were treated with or without the demethylating reagent 5-aza-2′-deoxycytidine. Methylation of the TIMP3 promoter was assessed in three regions by melt curve analysis and its expression was assessed by real-time RT-PCR. Tumors and proximal resection margins were obtained from 64 patients with esophageal squamous cell carcinoma from a region of high incidence in China. Methylation was assessed by melt curve analysis and expression by immunohistochemistry.
RESULTS： Methylation in one of the three promoter regions assessed correlated with gene silencing in esophageal cell lines. A degree of methylation of TIMP3 was found in only four esophageal squamous cell carcinomas, and partial loss of TIMP3 protein expression in just one.
CONCLUSION： Methylation and loss of expression of TIMP3 occurs infrequently in esophageal squamous cell carcinoma in a region of high incidence in China.     

The guanylate kinase domain of the beta-subunit of voltage-gated calcium channels suffices to modulate gating

Inactivation of voltage-gated calcium channels is crucial for the spatiotemporal coordination of calcium signals and prevention of toxic calcium buildup. Only one member of the highly conserved family of calcium channel β-subunits—Ca_Vβ—inhibits inactivation. This unique property has been attributed to short variable regions of the protein; however, here we report that this inhibition actually is conferred by a conserved guanylate kinase (GK) domain and, moreover, that this domain alone recapitulates Ca_Vβ-mediated modulation of channel activation. We expressed and refolded the GK domain of Ca_Vβ_2a, the unique variant that inhibits inactivation, and of Ca_Vβ_1b, an isoform that facilitates it. The refolded domains of both Ca_Vβ variants were found to inhibit inactivation of Ca_V2.3 channels expressed in Xenopus laevis oocytes. These findings suggest that the GK domain endows calcium channels with a brake restraining voltage-dependent inactivation, and thus facilitation of inactivation by full-length Ca_Vβ requires additional structural determinants to antagonize the GK effect. We found that Ca_Vβ can switch the inactivation phenotype conferred to Ca_V2.3 from slow to fast after posttranslational modifications during channel biogenesis. Our findings provide a framework within which to understand the modulation of inactivation and a new functional map of Ca_Vβ in which the GK domain regulates channel gating and the other conserved domain (Src homology 3) may couple calcium channels to other signaling pathways.     

Impact of poly-arginine peptides R18D and R18 on alteplase and tenecteplase thrombolysis in vitro,and neuroprotective stability to proteolysis

The poly-arginine peptides R18D and R18 represent novel potential neuroprotective treatments for acute ischaemic stroke. Here we examined whether R18D and R18 had any significant effects on the thrombolytic activity of alteplase (tPA) and tenecteplase (TNK) on clots formed from whole blood in an in vitro thrombolysis plate assay. R18D and R18 were examined at concentrations of 0.25, 0.5, 1, 2, 4, 8 and 16 µM during the 1-h thrombolytic assay. We also included the well-characterised neuroprotective NA-1 peptide as a control. R18D, R18 and NA-1 all reduced tPA or TNK percentage clot lysis by 0–9.35%, 0–3.44% and 0–4.8%, respectively. R18D, R18 and NA-1 had a modest and variable effect on the lag time, increasing the time to the commencement of thrombolysis by 0–9.9 min, 0–5.53 min and 0–7.16 min, respectively. Lastly, R18 and NA-1 appeared to increase the maximal activity of the thrombolysis reaction. In addition, the in vitro anti-excitotoxic neuroprotective efficacy of R18D and R18 was not affected by pre-incubation for 1–2 h or overnight with tPA or TNK, whereas only R18D retained high anti-excitotoxic neuroprotective efficacy when pre-incubated in a synthetic trypsin (TrypLE Express). The present in vitro findings suggest that neither R18D or R18 when co-administered with the thrombolytic inducing agents tPA or TNK are likely to have a significant impact when used clinically during clot thrombolysis and confirm the superior proteolytic stability of the R18D peptide.

     

Clinical correlation of asbestos bodies in BAL fluid

BACKGROUND: Asbestos bodies (AB) in BAL cells are specific markers of asbestos exposure. METHODS: We retrospectively reviewed BAL cytocentrifuge slides of 30 utility workers with a history of asbestos exposure and 30 normal volunteers. BAL cytocentrifuge slides were blinded and scanned under 40 x light microscope. RESULTS: AB were found more frequently in subjects with a history of asbestos exposure compared to normal volunteers (10 of 30 subjects, 33%, vs 0 of 30 subjects). The mean number of AB seen in the AB-positive group was 2.7 per slide. Demographic data were comparable including age, gender, and smoking. Exposure histories were also similar: duration > 20 years, onset > 30 years ago, and time since last exposure > 7 years. More AB-positive patients reported respiratory symptoms (70% vs 26%, p < 0.05). High-resolution CT scans of AB-positive patients revealed a higher prevalence of parenchymal disease (70% vs 26%, p < 0.05). AB-positive subjects had reduced pulmonary function compared to AB-negative subjects: FVC (86% vs 97% predicted), FEV(1) (77% vs 92% predicted, p < 0.05), and diffusion capacity of the lung for carbon monoxide (76% vs 104% predicted, p < 0.01). CONCLUSION: In individuals with a history of asbestos exposure, the presence of AB in BAL cells is associated with higher prevalence of parenchymal abnormalities, respiratory symptoms, and reduced pulmonary function.     

Living with multiple losses: Insights from patients living with pressure injury

Background

Pressure injury is a common problem. Its prevention and treatment is predominantly focussed on views, perceptions and knowledge of healthcare staff rather than on patient experience, particularly those patients living in their own homes.

Exhaled nitric oxide is age-dependent in asthma

We determined whether the exhaled nitric oxide (eNO) level in asthmatics is age-dependent. Eighty-seven asthmatic patients aged 2-41 years were studied. Hyperreactivity to adenosine 5'-monophosphate (AMP) was used to confirm asthma (相似文献