Occupational exposure and idiopathic pulmonary fibrosis: a multicentre case-control study in Korea

SETTING

Multicentred hospital-based cases and control subjects in Korea.

OBJECTIVE

To evaluate the association between idiopathic pulmonary fibrosis (IPF) and hazardous materials to which people are occupationally exposed.

DESIGN

A multicentre, hospital-based, matched case-control study was performed. The ratio of IPF cases to controls was 1:1 (n = 78 in each group). IPF cases and controls were matched in terms of age group, sex and place of residence. Conditional logistic regression analysis was performed.

RESULTS

In simple logistic regression analysis, exposure to metal dust and any exposure for >1 year in an occupational setting were significantly associated with IPF (metal dust OR 4.00, 95%CI 1.34-11.97; any exposure OR 3.67, 95%CI 1.02-13.14). After adjustment for environmental and military exposures and smoking history, the OR for metal dust exposure was 4.97 (95%CI 1.36-18.17) in multiple logistic regression analysis.

CONCLUSIONS

Metal dust was associated with incident IPF in Seoul and Gyeonggi Provinces in Korea. This information will be used to support a tailored preventive strategy in specific industries or occupations.

A programmable platform for sub-second multichemical dynamic stimulation and neuronal functional imaging in C. elegans

Caenorhabditis elegans (C. elegans) is a prominent model organism in neuroscience, as its small stereotyped nervous system offers unique advantages for studying neuronal circuits at the cellular level. Characterizing temporal dynamics of neuronal circuits is essential to fully understand neuronal processing. Characterization of the temporal dynamics of chemosensory circuits requires a precise and fast method to deliver multiple stimuli and monitor the animal's neuronal activity. Microfluidic platforms have been developed that offer an improved control of chemical delivery compared to manual methods. However, stimulating an animal with multiple chemicals at high speed is still difficult. In this work, we have developed a platform that can deliver any sequence of multiple chemical reagents, at sub-second resolution and without cross-contamination. We designed a network of chemical selectors wherein the chemical selected for stimulation is determined by the set of pressures applied to the chemical reservoirs. Modulation of inlet pressures has been automated to create robust, programmable sequences of subsecond chemical pulses. We showed that stimulation with sequences of different chemicals at the second to sub-second range can generate different neuronal activity patterns in chemosensory neurons; we observed previously unseen neuronal responses to a controlled chemical stimulation. Because of the speed and versatility of stimulus generated, this platform opens new possibilities to investigate neuronal circuits.

The Development of Emergency Medicine in South Korea: Academic Productivity in Highly Cited Journals

Introduction

The purpose of this study was to examine the number of publications by South Korean emergency physicians in highly cited journals and the increase in their numbers. It also sought to assess the impact factors of such publications.

Methods

The present study was a retrospective quantitative literature review of the publications by South Korean emergency physicians from 1996 to 2011 in the category of “emergency medicine” in the science edition of Journal Citation Reports 2011. We analysed the total number of articles published by South Korean emergency physicians and their impact factors.

Results

Between 1996 and 2011, the number of South Korean board-certified emergency physicians increased from 51 to 958, and 230 articles were published in 14 highly cited journals. The total impact factor (IF) of the original articles published during that period was 227.86, and the mean IF was 1.93. More than 10 articles had been published annually in the past 5 years in highly cited journals and there were over 400 South Korean board-certified emergency physicians.

Conclusions

Emergency medicine in South Korea started about 20 years ago, but academic productivity, indicated by at least ten articles annually in highly cited journals, was only achieved in the last five years. The mean IF of these articles was similar to that in other highly productive countries. (Hong Kong j.emerg.med. 2014;21:205-212)

Corpectomy and circumferential fusion for advanced thoracolumbar Kümmell's disease

BACKGROUND

The aim of this study was to investigate the surgical treatment of neurologically compromised advanced Kümmell's disease. The surgical treatment of Kümmell's disease has various options according to clinical and radiologic status. Far collapsed Kümmell's disease patients with neurological deficit need to be treated surgically.

MATERIALS AND METHODS

We retrospectively analyzed 22 patients operated to our hospital with neurologically compromised Kümmell's disease between January 2011 and January 2014. Surgical approach was vertebrectomy, mesh cage insertion and segmental cement-augmented pedicle screw fixation. Corpectomy tissue was examined histopathologically. Anterior vertebral heights, kyphotic angle, the visual analog scale (VAS) and the Frankel classification were used to evaluate the effects of the surgery.

RESULTS

The mean time of follow-up was 26 months (range, 13-40 months). The VAS, anterior vertebral heights, kyphotic angle and neurological state were improved significantly immediate postoperatively and at the last follow-up compared with the preoperative examinations (P < 0.05). Most of the patients in this study exhibited intravertebral clefts, and postoperative pathology revealed bone necrosis.

CONCLUSION

Posterior vertebrectomy with mesh cage insertion and segmental cement-augmented pedicle screw fixation is an effective option for advanced Kümmell's disease with neurological deficits.

Commutability and concordance of four hepatitis B virus DNA assays in an international multicenter study

BACKGROUND

HBV DNA is the most important molecular marker in hepatitis B, used to determine treatment indication and monitoring. Most patients require lifelong hepatitis B virus (HBV) management, thus viral load (VL) monitoring may be performed at different laboratories, with different HBV assays, which may result in different VL results. This multicenter study compares the commutability and concordance of results from four different HBV DNA assays: CAP/CTM HBVv2, HPS/CTM HBVv2 and the new cobas 6800/8800 HBV and cobas 4800 HBV assays.

METHODS

Across all four assays, HBV limit of detection (LoD) and linearity at lower concentrations were assessed using panels traceable to the World Health Organization international standard, and concordance was investigated at the important medical decision cutoffs 2000 and 20,000 IU/ml, using specimens from HBV-positive patients.

RESULTS

The calculated LoD via a probit curve was 2.7 IU/ml for cobas 6800/8800 HBV, 2.8 IU/ml for cobas 4800 HBV, 9.6 IU/ml for CAP/CTM HBVv2, and 6.2 IU/ml for HPS/CTM HBVv2. The average accuracy was comparable between cobas 6800/8800 HBV, cobas 4800 HBV and CAP/CTM HBVv2 (0.04-0.05 log₁₀ IU/ml), while a slightly lower accuracy was documented for HPS/CTM HBVv2 (-0.16 log₁₀ IU/ml). A total of 211-245 clinical samples were used for a pairwise comparison. Mean paired log differences ranged from -0.17 log₁₀ IU/ml to -0.01 log₁₀ IU/ml. Coefficient of determination was over 98% for all pairs with high overall percent agreement at the 2000 and 20,000 IU/ml cutoffs (from 91.7% to 96.3%). In a subset of samples with VL±0.5 log₁₀ to the 2000 and 20,000 IU/ml thresholds, concordance was still 72% and 82%, respectively.

CONCLUSIONS

The new cobas 6800/8800 HBV and 4800 HBV assays show high accuracy in samples with low-level viremia and a high concordance with the established HBV tests, CAP/CTM HBVv2 and HPS/CTM HBVv2, at 2000 and 20,000 IU/ml. Thus, all four HBV assays have high commutability and may be used interchangeably in routine clinical practice.

Reduction of Slit Diaphragm-associated Molecules by Sirolimus: Is it Enough to Induce Proteinuria?

Sirolimus (SRL), a mammalian target of rapamycin inhibitor, is widely used in transplantation, but the mechanisms whereby it induces adverse effects, such as proteinuria and edema, remain unclear. To determine whether isolated SRL induces proteinuria or not, the authors intraperitoneally injected C57BL/6 mice with different doses of SRL (0 mg/[kg·d], 3 mg/[kg·d], 10 mg/[kg·d], or 30 mg/[kg·d]) for 24 days. Urinary albumin excretion was then quantified using a double-sandwich enzyme-linked immunosorbent assay, and serum creatinine levels were measured using a single dry-film chemistry auto-analyzer. The mRNA expression levels of various genes were also measured by polymerase chain reaction. Urinary albumin was not detected in the SRL-treated mice, but serum creatinine levels were found to increase dose-dependently and were significantly higher in the animals treated with 30 mg/kg of SRL than in untreated controls. Glomerular mRNA expression profiling showed down-regulations of podocyte-related genes (Wilms tumor 1, synaptopodin, nephrin, CD2-associated protein, and podocin) and of transforming growth factor-beta (a marker of fibrosis) in sirolimus-treated mice. In addition, expressions of the antiapoptotic genes Bcl-2 and Bcl-xL were also down-regulated. Furthermore, the protein levels of these genes in mice kidney were also decreased by sirolimus. Although sirolimus treatment reduced the expressions of slit diaphragm-associated molecules and increased serum creatinine levels, it failed to induce proteinuria. Our findings indicate that proteinuria is not induced by isolated SRL treatment. Further studies are required to identify conditions in which sirolimus induces proteinuria.