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.     

Reverse dot blot assay (insertion site typing) for precise detection of sites of IS6110 insertion in the Mycobacterium tuberculosis genome

We have developed an amplification-based reverse dot blot assay for the detection of specific sites of insertion of the Mycobacterium tuberculosis insertion sequence IS6110. In this assay, a set of biotin-labeled amplicons representing the various copies of IS6110 and their flanking sequences is generated by linker-mediated PCR. The amplicons are then hybridized to immobilized oligonucleotide probes that are specific for known IS6110 insertion sites. The method was evaluated using an array of oligonucleotide probes corresponding to IS6110 insertion sites from M. tuberculosis strains CDC1551, Erdman, and H37Rv, and multidrug-resistant strain W. A set of 72 DNA samples from 60 M. tuberculosis clinical isolates was analyzed for the presence or absence of these insertion sites, and the assay was found to be highly reproducible. This method of identifying insertion sites has been named "insite" and can be used for the genotyping of M. tuberculosis complex strains based on IS6110 insertion site profiles.     

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.      

Benigne familiäre Neugeborenenkrämpfe Molekulare Pathogenese und Diagnostik

Benign familial neonatal convulsions are a rare monogenic form of idiopathic epilepsy characterized by the onset of frequent brief seizures after the second day of life. The seizures disappear spontaneously within a few weeks, but recurrent seizures later in life are common. Linkage studies located genes to chromosome 20q13.3 and 8q24, and the voltage-gated potassium channels KCNQ2 and KCNQ3 were recently identified. Since then, several mutations have been found leading to haplosufficiency of the ion channel. Functional studies showed that KCNQ2 and KCNQ3 are able to contribute to a heteromeric channel exhibiting kinetic and pharmacological properties similar to those of the native M current, the latter playing an important role in the regulation of neuronal excitability. This overview presents a summary of the molecular, genetic, and electrophysiological findings and discusses them with respect to their clinical relevance.     

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.     

Nicotinic acetylcholine receptors and epilepsy

The neuronal nicotinic acetylcholine receptors (nAChRs) have multiple roles in the brain: they are involved in signal transduction by fast synaptic transmission, axo-axonic transmission, and in the modulation of presynaptic transmitter release. Presynaptic nAChRs can increase the release of excitatory as well as of inhibitory transmitters, and can thereby control neuronal excitability. Furthermore, nAChRs which are expressed in fetal brain might also be involved in brain morphogenesis. Thus, the genes coding for the different nAChR subunits are likely candidates for several neurological disorders. The CHRNA4- or CHRNB2 subunits of the nAChR are associated with autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE), a rare monogenic type of idiopathic epilepsy. Electrophysiological studies demonstrated that ADNFLE mutations are causing both a loss-of-function and a gain-of-function in alpha4/beta2-heteropentameric nAChRs.     

A Korean kindred with autosomal dominant nocturnal frontal lobe epilepsy and mental retardation

BACKGROUND: A Korean family had distinctive clinical and neuroimaging features and carried the same genetic mutation that was found in a previously described Japanese kindred with autosomal dominant nocturnal frontal lobe epilepsy. OBJECTIVE: To describe the first Korean family with autosomal dominant nocturnal frontal lobe epilepsy. METHODS: Members of a large family, including 9 affected individuals from 3 generations, underwent a comprehensive genetic, clinical, electroencephalographic, neuropsychological, and neuroimaging evaluation. Affected members were tested for possible mutations in transmembrane regions 1 through 3 of the neuronal nicotinic acetylcholine receptor alpha4 subunit (CHRNA4) by direct sequencing and subsequent restriction analysis. RESULTS: Seizures began in childhood, presenting as nocturnal episodes of staring, confusion, shouting, perioral movements, unintelligible speech, and hand waving. Some patients had ictal or interictal epileptiform activity in the temporal and/or frontocentral areas. Neurological examination and brain magnetic resonance imaging results showed no abnormalities, except that all patients available for testing had mild to moderate mental retardation. Fluorodeoxyglucose F 18 with positron emission tomography showed mild decreased glucose uptake in the superior and middle frontal regions, more so on the left than on the right. Patient response to carbamazepine was poor. All affected members were heterozygous for the CHRNA4 Ser252Leu mutation. CONCLUSIONS: Disorders associated with mutations in the transmembrane region 2 of CHRNA4 are genetically and phenotypically heterogeneous. Distinctive features of this kindred include (1) mental retardation in all affected members available for testing, (2) abnormal brain findings on fluorodeoxyglucose F 18 with positron emission tomography, (3) poor response to carbamazepine, and (4) full penetrance.     

The CHRNB2 mutation I312M is associated with epilepsy and distinct memory deficits

Mutations in nAChRs are found in a rare form of nocturnal frontal lobe epilepsy (ADNFLE). Previously, some nAChR mutations have been described that are associated with additional neurological features such as psychiatric disorders or cognitive defects. Here, we report a new CHRNB2 mutation located in transmembrane region 3 (M3), outside the known ADNFLE mutation cluster. The CHRNB2 mutation I312M, which occurred de novo in twins, markedly increases the receptor's sensitivity to acetylcholine. Phenotypically, the mutation is associated not only with typical ADNFLE, but also with distinct deficits in memory. The cognitive problems are most obvious in tasks requiring the organization and storage of verbal information.