Organic solvent exposure for the chronic kidney disease: updated systematic review with meta-analysis.

Background: Studies on the relationship between organic solvent exposure and chronic kidney disease (CKD) have presented inconsistent results. Definition of CKD has changed in 2012, and other cohort studies have been newly published. Therefore, this study aimed to newly confirm the relationship between organic solvent exposure and CKD through an updated meta-analysis including additional studies. Methods: This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. The search was conducted on January 2, 2023 using Embase and MEDLINE databases. Case-control and cohort studies on the relationship between organic solvent exposure and CKD were included. Two authors independently reviewed full-text. Results: Of 5,109 studies identified, a total of 19 studies (control studies: 14 and cohort studies: 5) were finally included in our meta-analysis. The pooled risk of CKD in the organic solvent exposed group was 2.44 (1.72-3.47). The risk of a low-level exposure group was 1.07 (0.77-1.49). The total risk of a high-level exposure group was 2.44 (1.19-5.00). The risk of glomerulonephritis was 2.69 (1.18-6.11). The risk was 1.46 (1.29-1.64) for worsening of renal function. The pooled risk was 2.41 (1.57-3.70) in case-control studies and 2.51 (1.34-4.70) in cohort studies. The risk of subgroup classified as 'good' by the Newcastle Ottawa scale score was 1.93 (1.43-2.61). Conclusions: This study confirmed that the risk of CKD was significantly increased in workers exposed to mixed organic solvents. Further research is needed to determine the exact mechanisms and thresholds. Surveillance for kidney damage in the group exposed to high levels of organic solvents should be conducted. Trial Registration: PROSPERO Identifier: CRD42022306521.

Technetium-99m hand perfusion scintigraphy (Raynaud's scan) as a method of verification in hand arm vibration syndrome: a review.

It is important to assess the blood flow of fingers in the verification of hand-arm vibration syndrome. In the Republic of Korea, most assessments of the blood flow in the fingers are performed using a cold provocation test with finger skin color change. However, this test is a non-objective method with a relatively low sensitivity, leading to possible social and legal problems. Thus, we reviewed the characteristics of several tests that assess the blood flow in the fingers. Among these tests, using the radioactive isotope method, Raynaud's scan has a relatively higher sensitivity and specificity than other tests, provides objective results, and is approachable in many hospitals. So we suggest using Raynaud's scan as an alternative test when cold provocation test with finger skin color change is negative in vibration exposed worker.

A work-relatedness assessment in epidemiological case investigation of occupational cancers: II. Practice: an upper urinary tract cancer in a dyer.

An epidemiological case investigation of occupational cancer is conducted to determine the causation between the cancer and the worker's job. This review describes the overall process of work-relatedness assessment of the epidemiological case investigation through a case of upper urinary tract cancer (UUTC) in benzidine exposed worker in dyeing industry. Medical referrals, occupational history, material safety data sheet, and working environment monitoring submitted by the Korea Workers' Compensation and Welfare Service were reviewed. We further investigated literatures about the cotton dyeing industry, the domestic law and working environment monitoring reports. Benzidine was listed as an International Agency for Research on Cancer risk factor only for bladder cancer among urinary tract cancers, requiring different logical grounds for establishing causation. A literature review was conducted on the metabolic pathways of benzidine to establish biological plausibility. In addition, several papers were investigated that UUTC and bladder cancer share risk factors to extrapolate the epidemiological studies of bladder cancer. Epidemiologic studies of benzidine and bladder cancer were investigated. The worker is a 71-year-old man and performed dyeing and transporting at several dyeing factories for 29 years. The worker was diagnosed with UUTC based on radiologic and histologic results. It was critical to consider that he worked as a dyer for 3 years. The cancer was diagnosed in 2018, with a latent period of approximately 35 years. The worker performed cotton dyeing, and benzidine-based dye was mainly used. The quantitative exposure level of benzidine was reported from non-detection to 397.4 µg/m3. In biological metabolisms, N-acetylhydroxylamine changes DNA structure of urothelium. As a result of reviewing 4 epidemiological studies, the standardized incidence ratio and standardized mortality ratio were significantly high with 3 years of exposure. Work-relatedness was finally assessed as probable based on biological mechanisms and epidemiological evidence. This review will help solutions for work-relatedness assessment processes.

MicroRNA-98 is a prognostic factor for asbestos-induced mesothelioma.

Malignant pleural mesothelioma (MPM) is a type of cancer characterized by a short survival time and poor prognosis. Malignant pleural mesothelioma is most frequently associated with exposure to asbestos and other elongated mineral fibers. The aim of this study was to examine molecular differences between asbestos-exposed and non-exposed MPM patients and assess prognostic significances of molecular factors. Clinical and genetic data were downloaded from Cancer Genome Atlas. To identify the molecular differences, Significant Analysis of Microarray method was used. Prognostic significances of differentially expressed genes were confirmed by using Kaplan-Meier curve with the Log-Rank test. Although mRNAs did not exhibit any significant differences between the two patient groups, nine miRNAs were found to be down-regulated in the asbestos-exposed group. The top five pathways most relevant to the selected miRNAs were extracted through pathway enrichment analysis. Survival analysis revealed that high expression of only hsa-miR-98 was significantly associated with poor prognosis in patients with asbestos-exposed MPM. Evidence suggests that management of the aggressiveness and progression of asbestos-induced MPM may require high levels of hsa-miR-98 due to its tumor-suppressive role. This study might be helpful in enhancing our understanding of the biological mechanisms underlying asbestos-induced MPM and for acquiring greater insights into targeted therapy.Abbreviations: FDR: false discovery rate; MM: malignant mesothelioma; MPM: malignant pleural mesothelioma; mRNA: messenger RNA; miRNA: microRNA; SAM: significance analysis of microarrays; TCGA: the cancer genome atlas.

Crystallization Behavior of Amorphous Si3N4 and Particle Size Control of the Crystallized α-Si3N4.

Amorphous silicon nitride powder prepared by low-temperature vapor-phase reaction was heat treated at various temperatures for different periods of time to examine the crystallization behavior. The effects of the heat-treatment temperature and duration on the degree of crystallization were investigated along with the effect of the heat-up rate on the particle size, and its distribution, of the crystallized α-phase silicon nitride powder. A phase transition from amorphous to α-phase occurred at a temperature above 1400 degrees C. The crystallization. process was completed after heat treatment at 1500 degrees C for 3 h or at 1550 degrees C for 1 h. The crystallization process starts at the surface of the amorphous particle: while the outer regions of the particle become crystalline, the inner part remains amorphous. The re-arrangement of the Si and N atoms on the surface of the amorphous particle leads to the formation of hexagonal crystals that are separated from the host amorphous particle. The particle size and size distribution can be controlled by varying the heat-treatment profile (namely, the heat-treatment temperature, heating rate, and heating duration at the specified temperature), which can be used to control the relative extent of the nucleation and growth. The completion of most of the nucleation process by lowering the heat-up rate can be used to achieve a singlet particle size distribution. Bimodal particle size distribution can be achieved by fast heat-up during the crystallization process.