Effects of long working hours and the night shift on severe sleepiness among workers with 12‐hour shift systems for 5 to 7 consecutive days in the automobile factories of Korea

We investigated the effects of 12‐hour shift work for five to seven consecutive days and overtime on the prevalence of severe sleepiness in the automobile industry in Korea. [Correction added after online publication 28 Nov: Opening sentence of the summary has been rephrased for better clarity.] A total of 288 randomly selected male workers from two automobile factories were selected and investigated using questionnaires and sleep‐wake diaries in South Korea. The prevalence of severe sleepiness at work [i.e. Karolinska Sleepiness Scale (KSS) score of 7 or higher] was modeled using marginal logistic regression and included theoretical risk factors related to working hours and potential confounding factors related to socio‐economic status, work demands, and health behaviors. Factors related to working hours increased the risk for severe sleepiness at the end of the shift in the following order: the night shift [odds ratio (OR): 4.7; 95% confidence interval (CI): 3.6–6.0)], daily overtime (OR: 2.2; 95% CI: 1.7–2.9), weekly overtime (OR: 1.6; 95% CI: 1.0–2.6), and night overtime (OR: 1.6; 95% CI: 0.8–3.0). Long working hours and shift work had a significant interactive effect for severe sleepiness at work. Night shift workers who worked for 12 h or more a day were exposed to a risk of severe sleepiness that was 7.5 times greater than day shift workers who worked less than 11 h. Night shifts and long working hours were the main risk factors for severe sleepiness among automobile factory workers in Korea. Night shifts and long working hours have a high degree of interactive effects resulting in severe sleepiness at work, which highlight the need for immediate measures to address these characteristics among South Korean labor force patterns.     

Dual suppression with oral contraceptives and gonadotrophin releasing- hormone agonists improves in-vitro fertilization outcome in high responder patients

Certain patients have a tendency for high response to gonadotrophin therapy which is often not ameliorated with prior gonadotrophin- releasing hormone agonist (GnRHa) suppression. As a result, these patients are frequently cancelled and often experience ovarian hyperstimulation syndrome (OHSS) episodes during in-vitro fertilization (IVF)-embryo transfer cycles. Patients with polycystic ovarian syndrome (PCOS) have been noted to be particularly sensitive to exogenous gonadotrophin therapy. We have developed a protocol which is effective in improving IVF outcome in high responder patients, including those with PCOS. Oral contraceptive pills (OCP) are taken for 25 days followed by s.c. leuprolide acetate, 1 mg/day, which is overlapped with the final 5 days of oral contraceptive administration. Low-dose gonadotrophin stimulation is then initiated on the third day of withdrawal bleeding in the form of either human menopausal gonadotrophins or purified urinary follicle-stimulating hormone at a dosage of 150 IU/day. Over a 5 year period, we reviewed our experience utilizing this dual method of suppression in 99 cycles obtained in 73 high responder patients. There were only 13 cancellations prior to embryo transfer (13.1%). The clinical and ongoing pregnancy rates per initiated cycle were 46.5 and 40.4% respectively. Only eight patients experienced mild-moderate OHSS following treatment. For those patients who had undergone previous IVF-embryo transfer cycles at our centre, significant improvements were noted in oocyte fertilization rates, embryo implantation rates and clinical/ongoing pregnancy rates with this protocol. Hormonal analyses revealed that the chief mechanism may be through an improved luteinizing hormone/follicle-stimulating hormone ratio following dual suppression. An additional feature of this dual method of suppression is significantly lower serum androgen concentrations, particularly dehydroepiandrosterone sulphate.      

Coronary risk factors in school children in relation to their family history of coronary heart disease and hyperlipidemia

A school-based study was implemented to assess the family history of coronary heart disease (CHD) and hyperlipidemia (HL) in relation to serum lipoprotein and apolipoprotein levels. One hundred and twenty-five elementary school students (aged9–10 years) and 297 junior high school students (aged12–13 years) participated. Family history was evaluated by the following scoring method: positive family history in a parent. 2 points: in a grandparent. 1 point: and onset of CHD before age 60, 1 additional point. Family history of HL was positive in 8.2% of elementary school students, and 4.2% in junior high school students. Family history of CHD was positive in 11.5% of elementary students, and 11.0% in junior students. Family history score (FHS) for HL was related to serum total cholesterol (TC), low density lipoprotein cholesterol (LDLC), high density lipoprotein cholesterol, apolipoprotein A-T, apolipoprotein B (apoB) and lipoprotein (a) in elementary students, and to TC, LDLC, triglyceride and apoB in junior students. There was no relationship between FHS for CHD and serum lipoprotein or apolipoprotein levels in any student. The children with a positive FH of HL already demonstrated an atherogenic lipid profile while those with FH of CHD did not. which was probably because lipid profiles in children are more genetically mediated by a FH of HL than of CHD.     

The relationship between chronic kidney disease and SYNTAX score

Chronic kidney disease (CKD) is associated with increased risk of cardiovascular disease and death. We evaluated the association between CKD and severity of coronary artery stenosis by calculating SYNTAX Score in patients with left main coronary artery and/or 3-vessel coronary artery disease. Coronary angiograms of 217 patients were assessed. Chronic kidney disease was staged using the estimated glomerular filtration rate (eGFR, mL/min per 1.73 m(2)) prior to coronary angiography. Patients were divided into 5 groups according to the National Kidney Foundation Kidney Disease Outcome Quality Initiative (NKF KDOQI) Clinical Practice Guidelines (14). Patients with eGFR >90 mL/min per 1.73 m(2) (group 1), patients with eGFR 60 to 89 mL/min per 1.73 m(2) (group 2), patients with eGFR 30 to 59 mL/min per 1.73 m(2) (group 3), patients with eGFR >15 to < 30 per 1.73 m(2) and dialysis patients with eGFR < 15 per 1.73 m(2) were combined as group 4. The risk of significant lesion complexity increased progressively with decreasing kidney function (P = .001). Estimated glomerular filtration rate was a strong predictor of higher SYNTAX Score.     

Calcified carotid atherosclerotic plaque is associated less with ischemic symptoms than is noncalcified plaque on MDCT

OBJECTIVE: Risk assessment based on plaque vulnerability would be valuable in the management of asymptomatic carotid stenosis. The purpose of this study was to compare plaque morphology in symptomatic and asymptomatic patients with significant extracranial carotid artery stenosis using MDCT angiography. MATERIALS AND METHODS: We identified 31 patients with greater than 60% carotid artery stenosis on MDCT angiography using the criteria of the North American Symptomatic Carotid Endarterectomy Trial Collaborators. We analyzed plaque density by blinded review in Hounsfield units in the atherosclerotic plaques of 15 symptomatic and 21 asymptomatic stenotic vessels for classification as soft, intermediate, or calcified. Data were analyzed using multiple logistic regression. RESULTS: Even with age, traditional cardiovascular risk factors, and treatment taken into account, we found that calcified plaques were 21 times less likely to be symptomatic than noncalcified plaques (95% confidence interval for odds ratio, 0.003, 0.749; p = 0.030). No significant predictive value was found between soft (p = 0.23) or intermediate (p = 0.18) plaque morphology for the occurrence of symptoms. CONCLUSION: MDCT angiography may help risk-stratify patients with asymptomatic carotid artery stenosis. Extracranial carotid artery calcified plaques causing stenosis are significantly less likely to be symptomatic and thus may be more stable than noncalcified plaques. This finding may have implications for the interpretation of calcification of atherosclerotic plaque in other vascular beds.     

The Effects of Serum Potassium and Magnesium Levels in a Patient with Gitelman's Syndrome on the Timing of Ventricular Wall Motion and the Pattern of Ventricular Strain and Torsion

Gitelman's syndrome is a primary renal tubular hypokalemic metabolic alkalosis. Hypokalemia and hypomagnesemia can cause cardiac tissue excitability and conduction. Global ventricular mechanical function is directly related to the contractile properties of cardiac myocytes, which are largely dependent on the flow of ions such as potassium and magnesium. Here, we show that increased levels of potassium, in addition to magnesium, in a patient with Gitelman's syndrome significantly impacts the timing of ventricular wall motion and the pattern of ventricular strain and torsion. Two‐dimensional speckle tracking echocardiography was used for evaluation of the hypokalemic–hypomagnesemic period (first day) and third day after potassium chloride and magnesium replacement therapy. The transthoracic echocardiography showed that the percent ejection fraction was similar in hypokalemic–hypomagnesemic (63%) and normokalemic–normomagnesemic (after potassium and magnesium therapy, 67%) hearts. However, decreased left ventricular apical 4‐chamber peak systolic longitudinal strain, left ventricle global peak systolic strain, and global torsion values increased after potassium chloride and magnesium replacement therapy.     

Biological evaluation of glass ionomer cements

Summary. Sixty human premolar and canine teeth were used in this study. Class V cavities were prepared with a turbine handpiece. The experimental material was ASPA, with silicate cement and zinc oxide-eugenol cements being used as controls. The teeth were extracted approximately 4 days, 30 days or 90 days after insertion of the filling material. They were demineralized and prepared for histological examination. The test procedure and evaluation closely followed recommendations by the FDI (1980). The reaction at the short time interval for each material was similar, while at the intermediate and long periods silicate cement caused the most inflammation, zinc oxideeugenol cement the least, and ASPA an intermediate response. The reaction to ASPA was reduced at the long period compared with the intermediate period.     

Morphogenesis and Regulation of Bergmann Glial Processes During Purkinje Cell Dendritic Spine Ensheathment and Synaptogenesis

星形胶质细胞在突触形成中发挥重要作用,但星形胶质细胞突起如何在发育过程中与突触结构相联系还不是很清楚。本文分析在小脑突触发生过程中Bergmann胶质细胞(BG)突起生长的类型。本文发现在这个过程中,BG突起向外生长与树突棘增多的包被作用相关。此外,双光子时间分辩显像显示BG突起是高度动态的,在棘包被过程中突起趋于稳定。虽然突触活力依赖于肌动蛋白的聚合作用,但细胞骨架调节器Rac1和RhoG的活动在胶质细胞突起的动力或密度上并未发挥作用,而是对于保持突起长度起关键性作用。本文扩展这个发现,探查突起形态和包被之间的关系,发现缩短的突起导致棘覆盖的减少。本文进一步发现在BG表达dn-Rac1和低水平突触包被的区域,显示突触数量的增加。这些分析提示BG突起如何生长并包围突触结构,阐明BG突起结构对突触包被适当发育的重要性,并提示包被在突触形成中的作用。     

Auto-circler device (Tercan device) for marking a vertical scar mammaplasty

It is known that the desired shape and position of the nipple–areola complex may be difficult to achieve in vertical-scar reduction mammaplasty. The marking of a mosque-shaped areolar pattern varies from one surgeon to another, and therefore, periareolar trimming or resection may be inevitable with the use of such technique. We have developed a device to standardize the periareolar marking, and reduce the irregularity of the periareolar region. This device mimics the elasticity of normal breast tissue, and has the flexibility to be applicable to all breast types. We believe that this device improves the results of vertical-scar reduction mammaplasty and can eliminate the necessity of “last-minute” modifications intraoperatively.