Occupational cancer risk in pilots and flight attendants: current epidemiological knowledge

Occupational studies of aircrew in civil or military aviation did not receive much attention until the beginning of this decade. Since 1990, a number of epidemiological studies has been published on the cancer risk among flight personnel. Their results are equivocal: elevated cancer risks have been observed in some studies, but not in others. The exposure situation for pilots and flight attendants is unique with respect to several factors and particularly in that cosmic rays contribute substantially to their cumulative radiation dose. The average annual doses received are relatively low, however, and commonly range between 3 and 6 mSv. Results of epidemiological studies are presented as well as information on planned studies.     

The effects of double-shifts (15.5 hours) on sleep, fatigue and health

The aim of the present study was to investigate how "double-shifts" (15.5 hours) affects sleep, fatigue and self-rated health. The study was carried out on male construction workers of which 80% were long-distance commuters. The schedule involved two work periods and each work period involved two double shifts in a row. The subjects filled in a sleep/wake diary at 8 times across a year and a questionnaire at 3 times. They also wore an actigraph during one shift cycle. The results showed that sleepiness, and to a certain extent, mental fatigue increased during double shifts and accumulated across days. The short rest time (8.5 hours) between days caused insufficient sleep and approximately 5.5 hours of sleep was obtained between double shifts. Questionnaire data showed that complaints of insufficient sleep, exhaustion on awakening and pain symptoms increased across the year. It was concluded that a shift system involving double shifts has a negative effect on fatigue, recovery and health-related well-being.     

Phosphorylation of bovine neurofilament proteins by protein kinase FA (glycogen synthase kinase 3).

A highly purified preparation of protein kinase FA (where FA is the activating factor for phosphatase 1)/glycogen synthase kinase 3 from rabbit muscle readily phosphorylated bovine neurofilaments. All three neurofilament proteins, the high, middle, and low molecular proteins (NF-H, NF-M, and NF-L), were phosphorylated when intact filaments were incubated with the kinase. Experiments with individual proteins showed that NF-M was the best substrate. At protein concentrations of 0.13 mg/ml, the initial rate of NF-M phosphorylation was 30% of that observed for glycogen synthase. Km values were 0.24 mg/ml (7 x 10(-7) M tetramer) for glycogen synthase and 0.10 mg/ml (5 x 10(-7) M dimer) for NF-M. Vmax values were 0.36 mumol/min/mg for glycogen synthase and 0.035 mumol/min/mg for NF-M. Dephosphorylated NF-M was phosphorylated only half as much as native NF-M; this is consistent with the known substrate specificity of the kinase. The possible involvement of FA/GSK-3 in the phosphorylation of neurofilaments in vivo is discussed.     

Working hours and nonalcoholic fatty liver disease according to sleep duration

ABSTRACT

There is no study on the relationship between working hours and nonalcoholic fatty liver disease (NAFLD). The objective of the present study was to determine the relationship between working hours and NAFLD by sleep duration using a large set of abdominal ultrasonography examination data. Data from 194,625 patients who underwent health examinations from 2015 to 2017 were analyzed. Chi-square tests, linear-by-linear association and ANOVA were performed to compare general characteristics according to working hours. Multivariate logistic regression analysis was performed to determine the relationship between working hours and NAFLD by sleep duration. There was no significant relationship between working hours and NAFLD prevalence in the group of short sleep duration of ≤5 hours or the group of long sleep duration of ≥7 hours. The risk of NAFLD in the >52 working hour group was significantly higher (aOR, 1.09; 95% CI, 1.04–1.14) than that in the 40- to 52-hour working hour group after adjusting for confounding factors in the 5- to 6-hour sleep duration group. There was no significant difference between ≤40 working hours and 40 ~ 52 working hours in the 5 ~ 6 hours sleep duration group (aOR, 1.02; 95% CI, 0.97–1.06). In general, working hours were significantly related to NAFLD. There was a difference in the relationship between working hours and NAFLD according to sleep duration.     

Hopping and climbing gait of Japanese Pygmy Woodpeckers (Picoides kizuki).

Single cycles of hopping and climbing were investigated in Japanese Pygmy Woodpeckers Picoides kizuki using motion analyses on video. Body movements on substrate angled from 0-90 degrees were compared for every 10 degrees. The body was inclined forward during stance phase for both small and large substrate angles, and the inclination amplitude increased when the substrate angle increased. The tail was bent ventrally almost simultaneously to this body inclination, and its amplitude was apparently high at large substrate angles. Most of the gait parameters changed when the stride length increased. The minimum body-tail angle and most of the parameters representing body movements during stance phase changed when the substrate angle increased, probably because gravity pulled the birds further backward when they were moving on a steeper slope. These parameters showed a clear difference between the data on substrate steeper than 40 degrees and lower than 30 degrees. The abrupt changes in these parameters most likely mean that the motor pattern changed from hopping to climbing between these angles.     

Mitochondrial DNA variation and evolution of Japanese black cattle (Bos taurus).

This article describes complete mitochondrial DNA displacement loop sequences from 32 Japanese Black cattle and the analysis of these data in conjunction with previously published sequences from African, European, and Indian subjects. The origins of North East Asian domesticated cattle are unclear. The earliest domestic cattle in the region were Bos taurus and may have been domesticated from local wild cattle (aurochsen; B. primigenius), or perhaps had an origin in migrants from the early domestic center of the Near East. In phylogenetic analyses, taurine sequences form a dense tree with a center consisting of intermingled European and Japanese sequences with one group of Japanese and another of all African sequences, each forming distinct clusters at extremes of the phylogeny. This topology and calibrated levels of sequence divergence suggest that the clusters may represent three different strains of ancestral aurochs, adopted at geographically and temporally separate stages of the domestication process. Unlike Africa, half of Japanese cattle sequences are topologically intermingled with the European variants. This suggests an interchange of variants that may be ancient, perhaps a legacy of the first introduction of domesticates to East Asia.     

The epididymal region of the Japanese quail (Coturnix coturnix japonica).

The epididymal region of the Japanese quail was studied histologically. The organ consists of the extratesticular portion of the rete testis, the ductuli efferentes proximales and distales, the ducti conjugentes and ductus epididymidis. Distinct tubuli recti link the seminiferous tubules with the rete testis. The non-ciliated cells of the ductuli efferentes proximales and distales show, between them, certain internal structural differences which were highlighted. In 40% of the birds, the ductus deferens showed dark-grey pigments, regarded as melanin. The epididymal region was generally similar in structure to that of the domestic fowl, turkey and duck.     

Blood sampling and intravenous injections in Japanese quail (Coturnix coturnix japonica).

The suitability of five different sites (brachial, jugular, caudal tibial vein, external dorsal thoracic vein and the heart) were examined for blood sampling and intravenous injections in Japanese quail. In terms of safety, ease of collection, repeated collections or injections, the jugular vein was found to be the most suitable.     

Oxygen equilibrium characteristics of adult and fetal hemoglobin of Japanese monkey (Macaca fuscata).

Adult hemoglobin and fetal hemoglobin were obtained from Japanese monkey (Macaca fuscata) and their oxygen equilibrium characteristics were studied. (1) The oxygen affinity of fetal hemoglobin was higher than that of adult hemoglobin both in the presence and absence of 2,3-diphosphoglycerate. The presence of diphosphoglycerate lowers the oxygen affinity of adult hemoglobin much greater than does that of HbF and the diphosphoglycerate levels of red cells of adult and newborn monkeys are about the same. (2) The intensity of the Bohr effect, as expressed by -deltalogP50/deltapH, at pH 7.4 was in the order of fetal hemoglobin-diphosphoglycerate greater than adult hemoglobin-diphosphoglycerate greater than fetal hemoglobin greater than adult hemoglobin.     

Cyclic phosphorylation-dephosphorylation of rhodopsin in retina by protein kinase FA (the activator of ATP.Mg-dependent protein phosphatase).

The ATP.Mg-dependent protein phosphatase activating factor (protein kinase FA) was identified to exist in bovine retina. Furthermore, rhodopsin, the visual light pigment associated with rod outer segments in retina, could be well phosphorylated by kinase FA to about 0.9 mol of phosphates per mol of protein. Moreover, more than 90% of the phosphates in [32P]-rhodopsin could be completely removed by ATP.Mg-dependent protein phosphatase and the rhodopsin phosphatase activity was strictly kinase FA-dependent. Taken together, the results provide initial evidence that a cyclic phosphorylation-dephosphorylation of rhodopsin can be controlled by the retina-associated protein kinase FA, representing an efficient cyclic cascade mechanism possibly involved in the rapid regulation of rhodopsin function in retina.     

Cultivation of Eimeria tenella in Japanese quail embryos (Coturnix coturnix japonica).

Complete development of Eimeria tenella in Japanese quail embryos was observed. Sporozoites were inoculated into the allantoic cavity of 7-day-old Japanese quail embryos (Coturnix coturnix japonica), after which the infected embryos were incubated at 41 C. In the chorioallantoic membrane mature first generation schizonts, mature second generation schizonts, and gametes were detected at 48 hr postinoculation of sporozoites (PI), 84 hr PI, and 126 hr PI, respectively. Mature gametes and zygotes were found at 132 hr PI, and oocysts were detected at 138 hr PI. Mortality of embryos increased with increment of inoculum size of sporozoites. LD50 was 1.7 x 10(2) sporozoites. Oocyst production was also dependent on inoculum size. Oocysts harvested from embryos sporulated. The oocysts were inoculated into 13-day-old chickens, and oocysts, capable of sporulating normally, were recovered from ceca 7 days after inoculation.     

Regulation of hydroxyindole-O-methyltransferase gene expression in Japanese quail (Coturnix coturnix japonica).

Hydroxyindole-O-methyltrasferase (HIOMT) plays an important role as the final enzyme in the synthesis of melatonin. In this study, the expression of the HIOMT gene in Japanese quail was investigated with respect to tissue distribution and the effects of light and vitamin A deficiency. HIOMT mRNA in the pineal gland and eye had a clear daily rhythm with peak values in daytime. The testis also contained a detectable amount of HIOMT mRNA, which did not display a rhythmic change over a 24-h period. When birds were rendered vitamin A deficient through feeding with a vitamin A-free diet, the daily rhythm of the HIOMT gene almost disappeared in both the pineal gland and eye due to increases in the nighttime values. Our previous observations and these results suggest that vitamin A and a photo-signal are required to maintain the rhythmic expression of the HIOMT gene as well as the arylalkylamine N-acetyltransferase gene.     

Echolocation behaviours of the Japanese pipistrelle batPipistrellus abramus during foraging flight

The acoustic structure of echolocation pulses emitted by Japanese pipistrellePipistrellus abramus (Temminck, 1840) bats during different phases of aerial hawking is described here for the first time. Behavioural observations of the foraging flight in conjunction with acoustical analysis of echolocation pulses indicated a flight path consisting of four distinct phases following the reconnaissance or search phase. Short (∼4.68 ms) and relatively broadband frequencymodulated (FM) pulses (∼23.55 kHz bandwidth) were emitted at a repetition rate of 15 Hz during presumed target approach. Presumed insect capture consisted of an early and a late buzz phase. Both buzz types were emitted at high repetition rates (111 Hz in early to 222 Hz in late) and consisted of very short, broadband FM pulses (1.26 ms in early to 0.3 ms in late). There was also a characteristically sharp drop in both the peak and terminal frequencies of each echolocation pulse during the transition from early to late buzz. No pulses were recorded during the final phase of foraging referred to as a “post-buzz pause”. Thus the foraging behaviour of this species consisted of five sequential phases involving four broad types of echolocation pulses.