Proinsulin is converted to insulin by the concerted action of two sequence-specific subtilisin-like proteases termed prohormone convertase 2 (PC2) and prohormone convertase 3 (PC3). PC3 is a type I proinsulin-processing enzyme that initiates the sequential processing of proinsulin to insulin by cleaving the proinsulin molecule on the COOH-terminal side of the dibasic peptide, Arg31-Arg32, joining the B-chain and C-peptide. Thus, PC3 plays a key role in regulating insulin biosynthesis. Expressions of insulin and PC3, but not PC2, are coordinately regulated by glucose, consistent with the important role of PC3 in regulating proinsulin processing. NIDDM is associated with increased secretion of proinsulin and proinsulin-like molecules, suggesting that mutations in the PC3 gene may be involved in the development of this disorder. To examine this hypothesis, we have isolated and characterized the human PC3 gene and screened it for mutations in a group of Japanese subjects with NIDDM. The PC3 gene consists of 14 exons spanning more than 35 kb. The exon-intron organization of PC2 and PC3 genes are conserved, consistent with a common evolutionary origin for the prohormone convertase gene family. Single-strand conformational analysis and nucleotide sequencing of the entire coding region of the PC3 gene in 102 Japanese subjects with NIDDM revealed missense mutations in exons 2 (Arg/Gln53) and 14 (Gln/Glu638), neither of which was associated with NIDDM in this population. These data suggest that genetic variation in the PC3 gene is unlikely to be a major contributor to NIDDM susceptibility in Japanese.

Insulin is synthesized in the pancreatic beta cell as a larger precursor molecule proinsulin which is processed to insulin by the combined action of prohormone convertase 2 (PC2), prohormone convertase 3 (PC3) and carboxypeptidase E (CPE) [1±4]. Proinsulin has about 10 % of the potency of insulin and its conversion to insulin is necessary for full biological activity. Recent studies have shown that human proinsulin is first cleaved by PC3 to form 32±33 split proinsulin followed by the rapid removal of Arg31Arg32 by CPE to generate des 31, 32 proinsulin, and subsequent processing of this intermediate product by PC2 and CPE generates insulin and C-peptide [5].Elevated proinsulin level and/or proinsulin/insulin molar ratio is often observed in non-insulin-dependent diabetes mellitus (NIDDM) subjects [6±8]. Recent studies suggest that mutations in PC2, PC3 and/ or CPE might be responsible for the hyperproinsu- Diabetologia (1998) Organization of the human carboxypeptidase E gene and molecular scanning for mutations in Japanese subjects with NIDDM or obesity N. Utsunomiya, S. Ohagi, T. Sanke, H. Tatsuta, T. Hanabusa, K. NanjoThe First Department of Medicine, Wakayama University of Medical Science, Wakayama, JapanSummary Insulin is synthesized in the pancreatic beta cell as a larger precursor molecule proinsulin which is converted to insulin and C-peptide by the concerted action of prohormone convertase 2 (PC2), prohormone convertase 3 (PC3) and carboxypeptidase E (CPE). One of the features of non-insulin-dependent diabetes mellitus (NIDDM) is an elevation in the proinsulin level and/or proinsulin/insulin molar ratio suggesting that mutations in these three proinsulin processing enzymes might contribute to the development of NIDDM. The identification of a mutation in the CPE gene of the fat/fat mouse which leads to marked hyperproinsulinaemia and late-onset obesity and diabetes is consistent with a possible role for mutations in CPE in the development of diabetes and obesity in humans. In order to test this hypothesis, we have isolated and characterized the human CPE gene and screened it for mutations in a group of Japanese subjects with NIDDM and obesity. The human CPE gene consists of 9 exons spanning more than 60 kb. Primer extension analysis identified the transcriptional start site at ±141 bp from the translational start site. Single strand conformational polymorphism analysis and nucleotide sequencing of the promoter and entire coding region of the CPE gene in 269 Japanese subjects with NIDDM, 28 nondiabetic obese subjects and 104 nonobese and nondiabetic controls revealed three nucleotide changes, a G-to-T substitution at nucleotide ±53, a G-to-A substitution at nucleotide ±144 (relative to start of transcription) in the promoter region and a silent G-to-A substitution in codon 219. None of the nucleotide substitutions were associated with NIDDM or obesity. Thus, genetic variation in the CPE gene does not appear to play a major role in the pathogenesis of NIDDM or obesity in Japanese subjects. [Diabetologia (...

: Objective :The prediction of health impairment due to work overload is subjectively assessed based on recognized symptoms ; however, objective evaluation is primarily ideal in the field of occupational health. Recently, some biomarkers of autonomic function and/or oxidative stress were reported to be associated with fatigue. This study aimed to preliminarily investigate whether these biomarkers could be objective indicators for fatigue and stress among working women. Method: Participants included 118 full-time female workers (mean age 37.8 years ) , including 55 shift workers. Selfadministered questionnaires, such as visual analog scale (VAS) for general health, a lifestyle questionnaire, SF-8 for health-related quality of life, and K6 for mental health screening, were used. In addition, biomarkers such as acceleration plethysmogram ( APG ) , reactive oxygen metabolites-derived compounds (d-ROMs), and biological antioxidant potential (BAP) were measured. Results: A significant association was observed between BAP and VAS (r=0.482, p<0.01) among shift workers. However, other biomarkers such as APG and d-ROMs were not significantly associated with symptoms. d-ROMs were significantly correlated with age and body mass index. There was a significant negative correlation between BAP and smoking. Results of the APG ( lowfrequency (LF)/high-frequency (HF) ratio) were significantly correlated with BAP, but not with d-ROMs. The LF/HF ratio and BAP for shift workers were significantly higher than those for day-time workers. Conclusions : Our results suggest that APG and BAP are potential objective biomarkers for fatigue among working women, although further follow-up studies are needed to clarify the scope of usefulness of the biomarkers for fatigue.

Health and Welfare Organization Wakayama Rousai Hospital (2014 年 12 月 24 日 受付・2015 年 4 月 22 日 受理) 要 旨 当院において 2014 年 2 月から 3 月の 1 ヶ月間に，同一病棟において 3 名の患者から methicillin-resistant Staphylococcus aureus (MRSA)が検出された．3 名は入院後 48 時間以降の検出例であ った．さらに，検出同時期に長期入院 MRSA 保菌患者 1 名が同じ病棟に入院していた．これら 4 名から検出された MRSA 株は，薬剤感受性パターン(アンチバイオグラム)と phage open reading frame typing 法による遺伝子学的解析が一致した．我々は院内伝播を疑い，感染経路を明らかにす るために同病棟における環境の MRSA 培養と遺伝子学的解析を実施した．その結果，環境から 4 株の MRSA が検出され，患者由来株のアンチバイオグラムと遺伝子学的解析が同一であった．こ れらのことから，病棟の環境における MRSA の拡散が示唆された．その後，感染制御チームが環 境整備の徹底を含めた対策を講じ，院内伝播は終息した． これらの結果より，環境の MRSA 培養と POT 法を用いた遺伝子学的解析に基づいて環境整備 を徹底したことで，院内伝播を最小限に抑えられたと考えられた． Key wordsmethicillin-resistant Staphylococcus aureus (MRSA)，院内伝播，環境調査，infection control team (ICT)，PCR-based open-reading frames typing method (POT 法)