Engrailed: Pathological and physiological effects of a multifunctional developmental gene.

Engrailed-1 (EN1) is a developmental gene that encodes En1, a highly conserved transcription factor involved in regionalization during early embryogenesis and in the later maintenance of normal neurons. After birth, EN1 still plays a role in the development and physiology of the body; for example, it exerts a protective effect on midbrain dopaminergic (mDA) neurons, and loss of EN1 causes mDA neurons in the ventral midbrain to gradually die approximately 6 weeks after birth, resulting in motor and nonmotor symptoms similar to those observed in Parkinson's disease. Notably, EN1 has been identified as a possible susceptibility gene for idiopathic Parkinson's disease in humans. EN1 is involved in the processes of wound-healing scar production and tissue and organ fibrosis. Additionally, EN1 can lead to tumorigenesis and thus provides a target for the treatment of some tumors. In this review, we summarize the effects of EN1 on embryonic organ development, describe the consequences of the deletion or overexpression of the EN1 gene, and discuss the pathways in which EN1 is involved. We hope to clarify the role of EN1 as a developmental gene and present potential therapeutic targets for diseases involving the EN1 gene.

Involvement of the ventral tegmental area but not periaqueductal gray matter in the paradoxical rewarding and aversive effects of morphine.

The paradoxical effects of reward and aversion with abused drugs may interact to produce drug addiction, which is the so-called paradoxical effect hypothesis of abused drugs. However, there is no research examining how the ventral tegmental area (VTA) or periaqueductal gray matter (PAG) regulates morphine's paradoxical effect of reward and aversion. The present study addresses this issue, utilizing a high concentration of N-methyl-D-aspartic acid (NMDA) via injections to destroy the VTA or the PAG. Moreover, the study employed the new "pre- and postassociation" experimental paradigm (2010) to test whether the simultaneous rewarding and aversive effects of morphine can be affected by an NMDA lesion in the VTA or the PAG. The results indicated that the NMDA lesion of the VTA simultaneously reduced morphine-induced conditioned suppression of saccharin solution intake in conditioned taste aversion (CTA) and morphine-induced spent time in the preference compartment in conditioned place preference (CPP), whereas the PAG lesion did not change either measure. Thus, the VTA, but not the PAG, appears to contribute to the paradoxical effect reward in CPP and aversion in CTA induced by morphine. The VTA's involvement in morphine-induced CTA aversion and CPP reward supports the paradoxical effect hypothesis of abused drugs. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Occupational bladder cancer in a 4,4 -methylenebis(2-chloroaniline) (MBOCA)-exposed worker.

A 52-year-old male chemical worker was admitted to the hospital with a history of paroxysmal microscopic hematuria for about 2 years and nocturia with gross hematuria about five times per night for 2 months. He was a nonsmoker and denied a history of any other bladder carcinogen exposure except for occasional pesticide application during agricultural work. Intravenous urogram imaging showed a mass occupying half of the bladder capacity. Cystoscopy revealed a mass over the left dome of the bladder. Cystoscopic biopsy revealed a grade 3 invasive transitional cell carcinoma with marked necrosis. From 1987 until hospital admission in 2001, the patient had worked in a company that produced the 4,4 -methylenebis(2-chloroaniline) (MBOCA) curing agent. He did not wear any personal protective equipment during work. Ambient air MBOCA levels in the purification process area (0.23-0.41 mg/m3) exceeded the U.S. Occupational Safety and Health Administration's permissible exposure level. Urinary MBOCA levels (267.9-15701.1 microg/g creatinine) far exceeded the California Occupational Safety and Health Administration's reference value of 100 microg/L. This patient worked in the purification process with occupational exposure to MBOCA for 14 years. According to the environmental and biologic monitoring data and latency period, and excluding other potential bladder carcinogen exposure, this worker was diagnosed as having occupational bladder cancer due to high exposure to MBOCA through inhalation or dermal absorption in the purification area. This case finding supports that MBOCA is a potential human carcinogen. Safe use of skin-protective equipment and respirators is required to prevent workers from MBOCA exposure.

The effects of simultaneous exposure to methyl ethyl ketone and toluene on urinary biomarkers of occupational N,N-dimethylformamide exposure.

General regulations and risk assessment regarding toxicants are single-compound oriented even though humans are exposed to multi-chemicals in the general environment. This study investigated the effects of different levels of N,N-dimethylformamide (DMF) and co-exposure levels of methyl ethyl ketone (MEK) and toluene (TOL) on two biomarkers of DMF exposure: non-metabolized urinary (U-)DMF and the DMF metabolite urinary N-methylformamide (NMF). Thirty-five workers were selected from a two-stage field investigation strategy and were classified into four groups based on DMF exposure and co-exposure levels. Breathing-zone air concentrations of DMF, MEK, and TOL as well as dermal DMF exposure were determined. Post-shift U-DMF and U-NMF levels were determined for each individual. U-DMF concentrations were significantly higher in high-DMF groups than in low-DMF groups, but U-NMF concentrations were significantly (P<0.05) lower in the high-DMF-high-co-exposure group than in the high-DMF-low-co-exposure group; there were no significant differences between two low-DMF groups. The ratio of U-NMF to U-DMF showed the biotransformation from DMF to NMF was significantly suppressed at high co-exposure (P<0.001) for high-DMF exposure groups, possibly because of competitive inhibition of CYP2E1, the responsible enzyme involved. Due to the ubiquity of MEK/TOL in DMF-exposed occupational settings, the biological exposure index for occupational DMF exposure should be re-evaluated at high co-exposure levels.

An integrated approach for improving occupational health and safety management: the voluntary protection program in Taiwan.

A voluntary compliance program for occupational health and safety management, Voluntary Protection Programs (VPP), was implemented with a strategy of cooperation and encouragement in Taiwan. Due to limitations on increasing the human forces of inspection, a regulatory-based guideline addressing the essence of Occupational Health and Safety Management Systems (OHSMS) was promulgated, which combined the resources of third parties and insurance providers to accredit a self-improving worksite with the benefits of waived general inspection and a merit contributing to insurance premium payment reduction. A designated institute accepts enterprise's applications, performs document review and organizes the onsite inspection. A final review committee of Council of Labor Affairs (CLA) confers a two-year certificate on an approved site. After ten years, the efforts have shown a dramatic reduction of occupational injuries and illness in the total number of 724 worksites granted certification. VPP worksites, in comparison with all industries, had 49% lower frequency rate in the past three years. The severity rate reduction was 80% in the same period. The characteristics of Taiwan VPP program and international occupational safety and health management programs are provided. A Plan-Do-Check-Act management cycle was employed for pursuing continual improvements to the culture fostered. The use of a quantitative measurement for assessing the performance of enterprises' occupational safety and health management showed the efficiency of the rating. The results demonstrate that an employer voluntary protection program is a promising strategy for a developing country.

Study on occupational safety and health strategy for Taiwan.

The aim of this study was to establish a set of occupational safety and health (OSH) issues and development policies suitable for adoption in Taiwan. A survey was conducted on a sample of 102 experts and 235 industrial work safety personnel in Taiwan for statistical analysis of the general consensus, with the results showing such consensus in 104 individual policy indicators. Our results reveal that the most appropriate targets were considered to be annual 10% reductions in the 'occupational accident disability rate', 'occupational accident injury rate' and 'occupational diseases before 2010'. Responding to the specific question of the appropriate method of achieving a reduction in the number of accidents in Taiwan, the primary consideration for 13.4% of the experts and 10.6% of the industry personnel was 'promoting OSH awareness and enhancing the overall safety culture'. As regards the current OSH policy focus, 11.2% of the experts considered 'improving OSH legislation, standards and systems' to be the most important, whilst 8.9% of the industry personnel felt that 'recognizing work stress, overwork and emerging OSH issues' were the most important.

Identification of flurbiprofen and its photoproducts in methanol by gas chromatography-mass spectrometry.

A sample of 10 mM flurbiprofen in methanol (or ethanol) was photoirradiated with sixteen 8 W low-pressure quartz mercury lamps irradiated at 306 nm in a Panchum PR-2000 photochemical reactor. In total, four major photoproducts derived from each sample were observed from the HPLC chromatogram. The photoproducts were separated and their structures elucidated by various spectroscopic methods. Alternatively, using GC-MS, 11 major photoproducts were observed. A reaction scheme of flurbiprofen in methanol is proposed: the photochemical reaction routes occur mainly via esterification and decarboxylation, followed by oxidation with singlet oxygen to produce a ketone, alcohols and other derivatives.

Bladder cancer screening and monitoring of 4,4'-methylenebis(2-chloroaniline) exposure among workers in Taiwan.

OBJECTIVES: Transitional cell carcinoma of the urinary bladder is associated with occupational exposure to 4,4'-methylenebis(2-chloroaniline) (MBOCA). A program to monitor MBOCA levels in the work environment and to screen for bladder cancer was performed at four MBOCA manufacturing factories. METHODS: The U.S. Occupational Safety and Health Administration analytic method No. 24 was adopted in this study to measure air MBOCA concentrations. A total of 70 MBOCA-exposed workers and another 92 nonexposed workers were recruited for screening. Urine occult blood tests, urine cytology, tests for the urine tumor marker nuclear matrix protein, and abdominal ultrasonography were performed in all patients. Intravenous urography and cystoscopy were used to confirm the presence of bladder cancer. RESULTS: The air concentration of MBOCA was greatest in the purification area (0.23 to 0.41 mg/m3), followed by the washing area (less than 0.02 to 0.08 mg/m3) and neutralization area (less than 0.05 to 0.06 mg/m3). This study identified a current worker with proved bladder cancer. In addition, we also identified 1 worker with suspected malignant cells on urine cytology and 1 worker with atypical cytology combined with gross hematuria. Although the prevalence of atypical urinary cells and the nuclear matrix protein 22 tumor marker was not significantly different between the MBOCA-exposed workers and nonexposed workers as a whole or when grouped by sex, the prevalence of positive occult blood was marginally significantly (P = 0.055) greater in male exposed workers (18%) than in male nonexposed workers (7%). CONCLUSIONS: The findings of this study support the conclusions from other studies that MBOCA is potentially carcinogenic to humans. Control measures are needed to prevent overexposure from inhalation and skin absorption.