Effects of 6/6 and 4/8 Watch Systems on Sleepiness among Bridge Officers

During the last ten years, severe sleepiness or falling asleep by watch keeping officers has been a direct or a contributing factor in a number of maritime accidents. This study examined the relationship between two watch systems and its impact on fatigue and sleepiness in bridge officers. A questionnaire and a sleep/work diary were sent to a representative sample of the Finnish Maritime Officer Association. In all, 185 bridge officers answered the questionnaire on sleep, work hours, and safety, including the Skogby Excessive Daytime Sleepiness index (SEDS); 42% of the bridge officers worked two 4 h watches (4/8) per day, while 26% worked two 6 h watches per day (6/6). Ninety‐five of the participants completed a sleep diary for seven consecutive days while at sea. The timing of the watch duties and sleep was recorded, as was subjective sleepiness every 2 h using the Karolinska Sleepiness Scale (KSS). 17.6% of the participants had fallen asleep at least once while on duty during their career. Compared to the 4/8 watch system, the officers working the 6/6 watch system reported shorter sleep durations, more frequent nodding‐off on duty (7.3% vs. 1.5%), and excessive sleepiness (32% vs. 16% with SEDS>14). Based on a logistic regression analysis, high SEDS was significantly related with probable obstructive sleep apnea (OR 5.7), the 6/6 watch system (OR 4.0), and morningness‐eveningness while controlling simultaneously several individual and sleep‐related factors. Subjective sleepiness (KSS) was highest at 04:00 and 06:00 h. In a multivariate analysis, the KSS was significantly related to time of day, time after awaking, sleep length, and interactions of the watch systems with age, morningness‐eveningness, and Epworth sleepiness scale (ESS) score. Severe sleepiness at 04:00–06:00 h was especially problematic in the 6/6 watch system among evening types and among the bridge officers with high ESS. The results suggest the 6/6 watch system is related to a higher risk of severe sleepiness during the early morning hours compared to the 4/8 and the other watch systems assessed.     

Isolation and structural characterisation of 8-O-4/8-O-4- and 8-8/8-O-4-coupled dehydrotriferulic acids from maize bran

Two new dehydrotriferulic acids were isolated from saponified maize bran insoluble fiber using Sephadex LH-20 chromatography followed by semi-preparative RP-HPLC. Based on UV-spectroscopy, mass spectroscopy and one- and two-dimensional NMR experiments, the structures were identified as 8-O-4,8-O-4-dehydrotriferulic acid and 8-8(cyclic),8-O-4-dehydrotriferulic acid. Which of the possible phenols in the initially formed 8-8-dehydrodiferulate was etherified by 4-O-8-coupling with ferulate has been unambiguously elucidated. The ferulate dehydrotrimers which give rise to these dehydrotriferulic acids following saponification are presumed, like the dehydrodiferulates, to cross-link polysaccharides. Neither dehydrotriferulic acid described here involves a 5-5-dehydrodiferulic acid unit; only the 5-5-dehydrodimer may be formed intramolecularly. However, whether dehydrotriferulates are capable of cross-linking more than two polysaccharide chains remains open. Although the levels of the isolated ferulate dehydrotrimers are lower than those of the ferulate dehydrodimers, the isolation now of three different dehydrotriferulates indicates that trimers contribute to a strong network cross-linking plant cell wall polysaccharides.     

Effects of meals on objective and subjective measures of daytime sleepiness

Wells, Anita S., Nicholas W. Read, Chris Idzikowski, andJane Jones. Effects of meals on objective and subjective measures of daytime sleepiness. J. Appl.Physiol. 84(2): 507-515, 1998.Effects of recentfood ingestion on daytime sleepiness were assessed in 16 subjects (8 men and 8 women) who were each studied on two occasions, 28 days apart.On each occasion, subjects ate a high-fat low-carbohydrate (CHO)(fat/CHO energy ratio 54:41) meal and an isoenergetic low-fat high-CHOmeal (fat/CHO energy ratio 7:88) 4 h apart in a counterbalanced order.Sleepiness was measured at 2-h intervals by using the Multiple SleepLatency Test and the Akerstedt electroencephalograph sleepiness test.To control for circadian factors, one group (4 men, 4 women) ate themeals 2 h later than did the other group of subjects. There were nodifferences in sleepiness according to the composition of the meal.Sleepiness in the Multiple Sleep Latency Test was significantly greater1.5 h after the meals were eaten than before (F 11.37; df 1,15;P = 0.004). Sleepiness was alsoenhanced in the Akerstedt sleepiness test 3 h 20 min after the meals.The results suggest that the meals induced an enhancement in sleepiness that was not solely due to circadian rhythms.

     

结核分枝杆菌CFP10和ESAT6对巨噬细胞RAW264.7凋亡及AIM2/ASC/Caspase-8通路的影响

【背景】10 kD培养滤液蛋白(culture filtrate protein 10,CFP10)和6 kD早期分泌性抗原靶蛋白(early secretary antigenic target-6 kD,ESAT6)是结核分枝杆菌(Mycobacterium tuberculosis,Mtb)重要的毒力因子,能引起巨噬细胞的凋亡。【目的】探讨CFP10和ESAT6对巨噬细胞RAW264.7凋亡及AIM2/ASC/Caspase-8信号通路的影响。【方法】利用大肠杆菌表达并纯化获得了CFP10和ESAT6蛋白,重组蛋白处理巨噬细胞RAW264.7后,利用CCK8试剂盒检测细胞存活率,确定重组蛋白处理细胞浓度,利用Western blotting技术检测细胞凋亡相关蛋白及AIM2和ASC炎性小体的变化,利用流式细胞术检测细胞凋亡率。【结果】SDS-PAGE和Westernblotting结果表明重组蛋白CFP10和ESAT6表达正确,不同浓度的CFP10和ESAT6处理RAW264.7后,对细胞的增殖能力具有明显的抑制作用,当CFP10和ESAT6单独处理且浓度为5μg/mL时,细胞存...     

Effects of context on sleepiness self-ratings during repeated partial sleep deprivation

Ratings of subjective sleepiness are often used in laboratory and field studies of sleep loss and shifted sleep hours. Some studies suggest that such ratings might fail to reflect sleepiness as shown in physiology or performance. One reason for this may be the influence of the context of the rating. Social interaction or physical activity may mask latent sleepiness. The present study attempted to approach this question. Nine subjects participated in a partial sleep-deprivation experiment (five days of 4 h of time in bed [TIB]), preceded by two baseline days (8 h TIB) and followed by three recovery days (8 h TIB). Sleepiness was self-rated on the Karolinska Sleepiness Scale (KSS; scores of 1-9) after a period of relaxation, after a reaction-time test, and after 30 min of free activities. The results showed a strong increase in subjective sleepiness during sleep restriction and a significant difference between conditions. Free activity reduced the self-rated subjective sleepiness by 1.1 KSS units compared to the level of sleepiness self-rated at the end of the reaction-time test. Thus, the results of this study indicate that the context of a sleepiness rating affects the outcome of the rating.     

Structural determination of 6-C-diglycosyl-8-C-glycosyl-flavones and 6-C-glycosyl-8-C-diglycosylflavones by mass spectrometry of their permethyl ethers

Permethylated 6-C-diglycosyl-8-C-glycosylflavones and 6-C-glycosyl-8-C-diglycosylflavones gave well defined EIMS including the molecular peak and a fragmentation pattern characteristic of the 6-C-glycosyl residue. X″′-O-glycosides (8-C-disaccharides) are thus easily distinguished from X″-O-glycosides (6-C-disaccharides) and, in the latter, the position of the O-glycosidic bond should be deduced from the MS, after acid hydrolysis. Three new C-glycosylflavones have been characterized in this way from Spergularia rubra and Stellaria holostea.     

The 4-6-8 method of sequence analysis

A new method to obtain more sequence data from a single gel run is described. This method allows the reading of over 500 bases of sequence data from a single gel by taking advantage of the differential migration of specific sized dideoxy terminated chain lengths in sequencing gels containing variable percentages of acrylamide. The method is easy to use, requires no special equipment and requires no special technical abilities. We feel the methodology described will be useful for the average laboratory doing sequencing work.     

Studies on 6-aminoquinolones: synthesis and antibacterial evaluation of 6-amino-8-ethyl- and 6-amino-8-methoxyquinolones

From our quantitative structure-activity relationship (QSAR) study on a large set of 6-aminoquinolones, which indicated that a group larger than methyl could be allocated at C-8 position, we have synthesized two new series of 6-aminoquinolones characterized by the presence of an ethyl or a methoxy group at C-8 position. The antibacterial evaluation shows that, while the 8-ethyl derivatives were devoid of any antibacterial activity, the introduction of methoxy group gave compounds with good antibacterial activity, especially against gram-positive bacteria. A tentative explanation of the different behaviours among the 8-substituted analogues is given taking into account both the length and electronic properties of the C-8 groups.     

Effects of 4- and 8-h preexercise feedings on substrate use and performance

Seven well-trained male cyclists were studied during 105 min of cycling (65% of maximal oxygen uptake) and a 15-min "performance ride" to compare the effects of 4- and 8-h preexercise carbohydrate (CHO) feedings on substrate use and performance. A high CHO meal was given 1) 4-h preexercise (M-4), 2) 8-h preexercise (M-8), 3) 4-h preexercise with CHO feedings during exercise (M-4CHO), and 4) 8-h preexercise with CHO feedings during exercise (M-8CHO). Blood samples were obtained at 0, 15, 60, 105, and 120 min and analyzed for lactate, glucose, insulin, and glycerol. Total work output during the performance ride was similar for the M-4 (217,893 +/- 13,348 N/m) and M-8 trials (216,542 +/- 13,905) and was somewhat higher for the M-4CHO (223,994 +/- 14,387) and M-8CHO (224,702 +/- 15,709) trials (P = 0.059, NS). Glucose was significantly elevated throughout exercise, and insulin levels were significantly elevated at 15 and 60 min during M-4CHO and M-8CHO compared with M-4 and M-8 trials. Glycerol levels were significantly lower during the CHO feeding trials compared with placebo and were not significantly different during exercise when the subject had fasted an additional 4 h. The results of this study suggest that when preexercise meals are ingested 4 or 8 h before submaximal cycling exercise, substrate use and performance are similar.     

Effects of cations on dipalmitoyl phosphatidylcholine/cholesterol/water systems

X-ray diffraction studies have been made on the effects of cations upon the dipamitoyl phosphatidylcholine/water system, which originally consists of a lamellar phase with period of 64.5 Å and of excess water. Addition of 1 mM CaCl₂ destroys the lamellar structure and makes it swell into the excess water. the lamellar phase, however, reappears when the concentration of CaCl₂ increases: a partially disordered lamellar phase with the repeat distance of 150–200 Å comes out at the concentration of about 10 mM, the lamellar diffraction lines become sharp and the repeat distance decreases with increasing CaCl₂ concentration. A small amount of uranyl acetate destroys lamellar phase in pure water. MgCl₂ induces the lamellar phase of large repeat distance, whereas LiCl, NaCl, KCl, SrCl₂ and BaCl₂ exhibit practically no effect by themselves. Addition of cholesterol to the phosphatidylcholine bilayers tends to stabilize the lamellar phaseThe high-angle reflections indicate that molecular arrangements on phosphatidylcholine bilayers change at CaCl₂ concentrations around 0.5 M. The bilayers at high CaCl₂ concentration seem to consist of two phases of pure phosphatidylcholine and of equimolar mixture of phosphatidylcholine and cholesterol.     

Splicing factor Prp8 governs U4/U6 RNA unwinding during activation of the spliceosome

The pre-mRNA 5' splice site is recognized by the ACAGA box of U6 spliceosomal RNA prior to catalysis of splicing. We previously identified a mutant U4 spliceosomal RNA, U4-cs1, that masks the ACAGA box in the U4/U6 complex, thus conferring a cold-sensitive splicing phenotype in vivo. Here, we show that U4-cs1 blocks in vitro splicing in a temperature-dependent, reversible manner. Analysis of splicing complexes that accumulate at low temperature shows that U4-cs1 prevents U4/U6 unwinding, an essential step in spliceosome activation. A novel mutation in the evolutionarily conserved U5 snRNP protein Prp8 suppresses the U4-cs1 growth defect. We propose that wild-type Prp8 triggers unwinding of U4 and U6 RNAs only after structurally correct recognition of the 5' splice site by the U6 ACAGA box and that the mutation (prp8-201) relaxes control of unwinding.     

Opisthorchis viverrini excretory/secretory products induce toll-like receptor 4 upregulation and production of interleukin 6 and 8 in cholangiocyte

Biliary tract infection with the Group I carcinogenic liver fluke Opisthorchis viverrini is associated with severe inflammation leading to cholangiocarcinoma--a major biliary cancer in Southeast Asia. However, mechanism(s) by which the liver fluke induces host mucosal immune/inflammatory responses is unclear. In the present study we address whether a normal immortalized human cholangiocyte cell line (H69 cells) recognizes and responds to O. viverrini excretory/secretory products (OVES). Expression of multiple TLRs, activation of NF-κB, and expression of pro-inflammatory cytokines were monitored in the presence and absence of OVES. Our results showed that OVES induced increased cholangiocyte TLR4 mRNA expression, induced IκB-α degradation in a MyD88-dependent manner, and activated NF-κB nuclear translocation. Moreover, OVES induced expression and secretion of the strong chemoattractant chemokine interleukin 8 (IL-8) and pro-inflammatory cytokine IL-6. These results demonstrate that secreted/excreted products of O. viverrini are recognized by human cholangiocytes and initiate innate mucosal immunity/inflammatory cascades, a primary event in the pathogenesis of opisthorchiasis and cholangiocarcinoma.     

Effects of cations on dipalmitoyl phosphatidylcholine/cholesterol/water systems.

X-ray diffraction studies have been made on the effects of cations upon the dipalmitoyl phosphatidylcholine/water system, which originally consists of a lamellar phase with period of 64.5 A and of excess water. Addition of 1 mM CaCl2 destroys the lamellar structure and makes it swell into the excess water. The lamellar phase, however, reappears when the concentration of CaCl2 increases: a partially disordered lamellar phase with the repeat distance of 150-200 A comes out at the concentration of about 10 mM, the lamellar diffraction lines become sharp and the repeat distance decreases with increasing CaCl2 concentration. A small amount of uranyl acetate destroys the lameellar phase in pure water. MgCl2 induces the lamellar phase of large repeat distance, whereas LiCl, NaCl, KCl, SrCl2 and BaCl2 exhibit practically no effect by themselves. Addition of cholesterol to the phosphatidylcholine bilayers tends to stabilize the lamellar phase. The high-angle reflections indicate that molecular arrangements in phosphatidylcholine bilayers change at CaCl2 concentrations around 0.5 M. The bilayers at high CaCl2 concentration seem to consist of two phases of pure phosphatidylcholine and of equimolar mixture of phosphatidylcholine and cholesterol.     

New onset and natural remission of excessive daytime sleepiness and its correlates among high-school students

Sleep and Biological Rhythms - Excessive daytime sleepiness (EDS) is highly prevalent among high-school students, and preventa-tive measures against it are essential for promotion of school health....     

Effects of sleep disruption on cognitive performance and mood in medical house officers.

Twelve medical house officers were tested on a battery of memory, concentration, and work related tasks after three conditions: a night spent off duty; a night spent on call; and a night spent admitting emergency cases. Short term recall, but not digit span, concentration, or work related abilities, was impaired after a night of emergency admissions. A night spent on call had no effect on cognitive performance. Self reported mood scores showed that house officers were more deactivated (indicating a lack of vigour and drive) after nights of emergency admissions but not after nights on call. Significant between subject differences were found for five of the eight cognitive tests. Though loss of sleep and long hours of work have an effect on memory and mood, the individual differences among doctors are the main source of the variance in performance of tasks.     

MRP8/14 mediates macrophage efferocytosis through RAGE and Gas6/MFG‐E8, and induces polarization via TLR4‐dependent pathway

Myeloid‐related protein 8/14 (MRP8/14) participates in various inflammatory responses, however, its effect on macrophage efferocytosis remains unclear. Here, we demonstrate that MRP8/14 significantly inhibits the efferocytosis of apoptotic thymocytes by mouse bone marrow‐derived macrophages (BMDMs), which later proves to be associated with the receptor for advanced glycation end products (RAGE) or for reducing the expression of growth arrest‐specific protein 6 and milk fat globule epidermal growth factor 8, independent of RAGE. Furthermore, MRP8/14 promotes polarization of BMDMs from the M₂‐ to M₁‐like phenotype by upregulating expression of M₁‐related surface receptor proteins and signature M₁‐marker genes and by downregulating signature M₂‐marker gene expression, which depends on Toll‐like receptor 4 and p38 mitogen‐activated protein kinase/nuclear factor κB pathways. Thus, we report a significant inhibitory effect of MRP8/14 on macrophage efferocytosis and MRP8/14‐mediated phenotypic polarization, which may be helpful in developing novel therapeutic strategies leading to inflammation resolution.     

8-异戊烯基柑橘素促进体外培养成骨细胞成熟矿化的研究

研究8-异戊烯基柑橘素对体外培养大鼠颅骨成骨细胞(rat skull osteoblasts,ROB)的分化成熟及生物矿化的影响.取新生大鼠颅骨多次酶消化法得到成骨细胞,培养于含10%FBS的MEM培养液中,3天后首次换液,待细胞铺满皿底传代培养.以碱性磷酸酶(alkaline phosphatase,ALP)为检测指标,96孔板梯度筛选作用最佳浓度,在最佳浓度作用并成骨性诱导培养的第3、6、9、12天测ALP活性、钙盐沉积量;第12天进行ALP和钙化结节组织化学染色及计数;成骨性诱导后不同时间点提取Total RNA,RT real-time PCR法检测成纤维细胞生长因子(bFGF)、胰岛素样生长因子-1(IGF-1)、成骨相关转录因子Osterix、Runx-2和骨形态发生蛋白-2(BMP-2)的基因表达情况;成骨性诱导的第4、8、12天裂解获得细胞总蛋白,蛋白质印迹法检测人Ⅰ型胶原蛋白(COL-Ⅰ)的蛋白质表达量.研究结果表明:1×10-6 mol/L能显著促进成骨细胞的成熟分化,表现为提高ROB的ALP活性、促进钙盐沉积、增加钙化结节数量;提高bFGF、IGF-1、Osterix、Runx-2和BMP-2 mRNA表达水平;促进COL-Ⅰ的合成.由此可知终浓度为1×10-6 mol/L 8-异戊烯基柑橘素能显著促进ROB的分化成熟及生物矿化,证明8-异戊烯基柑橘素能促进成骨细胞的分化成熟及生物矿化,作为促进骨修复和抗骨质疏松的有效成分具有较大的药用价值.     

小麦-簇毛麦6VS/6AL易位染色体对小麦农艺性状的影响

南京农业大学细胞遗传研究所选育的小麦－簇毛麦6VS/6AL易位系在6VS上携有Pm21基因,用它作抗源已选育出一批高抗白粉病的新品系和新品种。为了研究6VS/6AL易位染色体对普通小麦农艺性状的影响,本研究选用由不同生态类型的推广品种与6VS/6AL易位系经过杂交回交选育的11个高代品系(种)及其轮回亲本和3份涉及6VS/6AL的高代分离品系以及5个F2群体,对产量、株高、穗长、穗粒数、穗粒重和千粒重等农艺性状进行比较分析。结果表明,6VS/6AL易位染色体对后代的小穗数、穗粒数、穗粒重和产量等农艺性状没有表现出明显的影响,对穗长和千粒重表现出一定的正向效应。多数6VS/6AL衍生品系的株高与亲本相比有所增加,但在同一组合的不同品系之间表现出一定的差异,在育种过程中通过选择能够改变增高趋势。6VS/6AL易位系对白粉病免疫,并且遗传稳定,对小麦的抗病育种是很有潜力的抗源亲本。     

Counting on mitogen-activated protein kinases--ERKs 3, 4, 5, 6, 7 and 8

Signal transduction pathways in eukaryotic cells integrate diverse extracellular signals, and regulate complex biological responses such as growth, differentiation and death. One group of proline-directed Ser/Thr protein kinases, the mitogen-activated protein kinases (MAPKs), plays a central role in these signalling pathways. Much attention has focused in recent years on three subfamilies of MAPKs, the extracellular signal regulated kinases (ERKs), c-Jun N-terminal kinases (JNKs) and the p38 MAPKs. However, the ERK family is broader than the ERK1 and ERK2 proteins that have been the subject of most studies in this area. Here we overview the work on ERKs 3 to 8, emphasising where possible their biological activities as well as distinctive biochemical properties. It is clear from these studies that these additional ERKs show similarities to ERK1 and ERK2, but with some interesting differences that challenge the paradigm of the archetypical ERK1/2 MAPK pathway.