Unique features of the motility and structures in the flagellate polar region of Campylobacter jejuni and other species: an electron microscopic study

Similarly to Helicobacter pylori but unlike Vibrio cholerae O1/O139, Campylobacter jejuni is non‐motile at 20°C but highly motile at ≥37°C. The bacterium C. jejuni has one of the highest swimming speeds reported (>100 μm/s), especially at 42°C. Straight and spiral bacterial shapes share the same motility. C. jejuni has a unique structure in the flagellate polar region, which is characterized by a cup‐like structure (beneath the inner membrane), a funnel shape (opening onto the polar surface) and less dense space (cytoplasm). Other Campylobacter species (coli, fetus, and lari) have similar motility and flagellate polar structures, albeit with slight differences. This is especially true for Campylobacter fetus, which has a flagellum only at one pole and a cup‐like structure composed of two membranes.     

Genetic variability characterization of the moroccan houbara bustard (Chlamydotis undulata undulata) inferred from pedigree analysis

A Moroccan Houbara Bustard pedigree was analyzed to evaluate the genetic variability in captive breeding population using genealogical approaches. The whole Houbara breeding flock (WP) for the period 1993–2004 was made up of 531 birds comprising 346 females and 185 males. The reference population (RP) comprised 198 individuals ready for reproduction from 2000 to 2004 cohorts. The corresponding percentage of known ancestors was estimated as 98.23% for the parent generation, 41.19% for the grandparent generation and 7.00% for the great grandparents generation. The average generation interval for Houbara was computed as 4.64 years. Genetic variability loss per generation was ascertained using the effective population size (), the founder genome equivalent (fge), the effective number of ancestors and founders (fa) and (fe), respectively, for the RP and across each cohort. The results showed no bottleneck events in the breed but some loss of genetic variability just after the initiation of the conservation program. However, the annual effective population size based on the realized increase in inbreeding () was estimated to be 207 for the RP and 1,000 for the WP. With regard to conservation breeding schemes, the genealogical evidence presented here is very useful as it revealed the positive effect of migration on Houbara breeding. The mating strategies will assist in the future control and management of the genetic variability of this population. Zoo Biol. 32:366‐373, 2013. © 2012 Wiley Periodicals, Inc.     

Effect of Lysine Addition on Growth of Black Iguana (Ctenosaura pectinata)

The effects of the addition of lysine to commercial feed given to captive black iguana (Ctenosaura pectinata) were evaluated in terms of growth and feed digestibility. Twenty‐eight‐day‐old black iguana with an initial weight of 5.5 ± 0.3 g were housed individually in cages measuring 45 × 45 × 45 cm. The experiment lasted 150 days. The ambient temperature ranged from 28 to 35°C with a relative humidity of 60 to 95%. Treatments consisted of the addition of different percentages of lysine to the feed (0.0, 0.1, 0.2, and 0.3%, dry matter [DM] base). There was a linear response (P < 0.01) in daily gain (68, 112, 118, and 151 mg/d) and daily intake (251, 289, 297, and 337 mg/d) for levels from 0 to 0.3%, respectively, as well in the growth in head size, snout–vent length, and total length. The digestibility of DM, neutral detergent fiber, and acid detergent fiber were reduced linearly (P < 0.01) as lysine levels increased. Intake and digestibility were negatively correlated (r = –0.74; P < 0.001). It is concluded that the addition of lysine to the black iguana diet in the first months of life is important to stimulate growth and intake. Zoo Biol 32:277–280, 2013. © 2012 Wiley Periodicals, Inc.     

Thermoregulatory effects of melatonin in relation to sleepiness

Thermoregulatory processes have long been implicated in the initiation of human sleep. In this paper, we review our own studies conducted over the last decade showing a crucial role for melatonin as a mediator between the thermoregulatory and arousal system in humans. Distal heat loss, via increased skin temperature, seems to be intimately coupled with increased sleepiness and sleep induction. Exogenous melatonin administration during the day when melatonin is essentially absent mimics the endogenous thermophysiological processes occurring in the evening and induces sleepiness. Using a cold thermic challenge test, it was shown that melatonin‐induced sleepiness occurs in parallel with reduction in the thermoregulatory set‐point (threshold); thus, melatonin may act as a circadian modulator of the thermoregulatory set‐point. In addition, an orthostatic challenge can partially block the melatonin‐induced effects, suggesting an important role of the sympathetic nervous system as a link between the thermoregulatory and arousal systems. A topographical analysis of finger skin temperature with infrared thermometry revealed that the most distal parts of the fingers, i.e., fingertips, represent the important skin regions for heat loss regulation, most probably via opening the arteriovenous anastomoses, and this is clearly potentiated by melatonin. Taken together, melatonin is involved in the fine‐tuning of vascular tone in selective vascular beds, as circulating melatonin levels rise and fall throughout the night. Besides the role of melatonin as “nature's soporific”, it can also serve as nature's nocturnal vascular modulator.     

Hypersomnolence and Accidents in Truck Drivers: A Cross‐Sectional Study

Truck drivers are more likely to suffer severe injury and death due to certain truck driving characteristics. Identifying and preventing factors associated with accidents in this population is important to minimize damage and improve road safety. Excessive daytime sleepiness is a major public health problem, leading to impaired cognitive function, reduced alertness, and increased risk of motor vehicle crashes. The aim of this cross‐sectional study was to determine the prevalence and predictors of hypersomnolence (defined as an Epworth Sleepiness Scale score greater than 10) among truck drivers. Three hundred male truck drivers were studied. Quality of sleep was assessed by the Pittsburgh Sleep Quality Index, and the association between demographic, clinical, and occupational data with excessive sleepiness was analyzed. The mean daily sleep duration was 5.6±1.3 h, and poor quality of sleep was found in 46.3% of the individuals. Hypersomnolence was found in 46% of the drivers and was associated with younger age, snoring, and working >10 h without rest. A positive correlation between hypersomnolence and previous accidents was detected (p=0.005). These results show that sleep deprivation and hypersomnolence are frequent among truck drivers. The treatment of sleep‐disordered breathing and the implementation of educational programs, particularly targeting younger drivers and promoting increased awareness of the deleterious effects of sleep loss and work overload, may help to reduce hypersomnolence and accidents among truck drivers.     

Short Sleep Is Associated with Obesity among Truck Drivers

Recent studies suggest that short‐sleep duration is independently associated with obesity in the general population. The population of truck drivers is of particular interest, because they frequently work irregular shifts that in turn are associated with short‐sleep duration. In addition, truck drivers have a high prevalence of sedentary habits, poor diet, and obesity. The present study aimed at verifying the association between sleep patterns and factors associated with obesity in this population. The study sample consisted in 4,878 truck drivers who participated in a campaign promoted by a highway company in the State of São Paulo, Brazil. This campaign offered highway truck drivers a medical and laboratorial evaluation. The truck drivers completed a questionnaire concerning demographic data, sleep duration, consumption of medications, and medical problems, such as diabetes, cardiopathy, and hypertension; as well as the Berlin questionnaire, which is able to discriminate low and high risk for obstructive sleep apnea. Blood samples were collected to measure glucose and cholesterol levels. Also, body weight and height were registered to calculate the body mass index (BMI). The mean age (±SD) of the truck drivers studied was 40±10 years. Out of the truck drivers analyzed, 28.3% (n=1,379) had a BMI ≥30.0 Kg/m² (obesity). Among the 4,878 drivers included in the study, 1,199 (24.6%) were on medications and 334 (6.8%) were diabetic. Drivers (26.9%) with the greater BMI had a short sleep length. The independent factors associated with obesity were sleep duration <8 h/day (OR=1.24), age >40 years (OR=1.20), glucose levels >200 (OR=2.02), cholesterol levels >240 (OR=1.57), snoring (OR=1.74), and hypertension (OR=2.14). Smoking was not associated with obesity (OR=0.69), and diabetes was considered a control variable. In conclusion, this study supports the hypothesis that short sleep duration as well as age >40 years are independently associated with obesity. This particular combination (short‐sleep duration and obesity) is independently associated with several healthcare problems, including high levels of cholesterol, glucose, snoring, and hypertension. However, due to the cross‐sectional nature of this study, no cause–effect relationship can be drawn from these results.     

Circadian Time‐Effect of Orally Administered Loratadine on Plasma Pharmacokinetics in Mice

Little is known about the chronopharmacokinetics of loratadine, a long‐acting tricyclic antihistamine H₁ widely used in the treatment of allergic diseases. Hence, the pharmacokinetics of loratadine and its major metabolite, desloratadine, were investigated after a 20 mg/kg dose of loratadine had been orally administered to comparable groups of mice (n=33), synchronized for three weeks to 12 h light (rest span)/12 h dark (activity span). The drug was administered at three different circadian times (1, 9, and 17 h after light onset [HALO]). Multiple blood samples were collected over 48 h, and plasma concentrations of loratadine and desloratadine were determined by high performance liquid chromatography. There were no significant differences in T_max of loratadine and desloratadine between treatment‐time different groups. However, the elimination half‐life (t1/2) of the parent compound and its metabolite was significantly longer (p<0.01) following administration at 9 HALO (t1/2 loratadine and desloratadine 5.62 and 4.08 h at 9 HALO vs. 4.29 and 2.6 h at 17 HALO vs. 3.26 and 3.27 at 1 HALO). There were relevant (p<0.05) differences in C_max between the three treated groups for loratadine and desloratadine; 133.05±3.55 and 258.07±14.45 ng/mL at 9 HALO vs. 104.5±2.61 and 188.62±7.20 ng/mL at 1 HALO vs. 94.33±20 and 187.75±10.79 ng/mL at 17 HALO. Drug dosing at 17 HALO resulted in highest loratadine and desloratadine total apparent clearance values: 61.46 and 15.97 L/h/kg, respectively, whereas loratadine and desloratadine clearances (CL) were significantly slower (p<0.05) at the other administration times (loratadine and desloratadine CL was 57.3 and 14.22 L/h/kg at 1 HALO vs. 43.79 and 12.89 L/h/kg at 9 HALO, respectively). The area under the concentration‐time curve (AUC) of loratadine and desloratadine was significantly (p<0.05) greater following drug administration at 9 HALO (456.75 and 1550.57 (ng/mL) · h, respectively); it was lowest following treatment at 17 HALO (325.39 and 1252.53 (ng/mL) · h, respectively). These pharmacokinetic data indicate that the administration time of loratadine significantly affected its pharmacokinetics: the elimination of loratadine and its major metabolite desloratadine.     

Effects of 12‐Hour Rotating Shifts on Menstrual Cycles of Photoelectronic Workers in Taiwan

12 h rotating shifts are common in high‐tech industries in Taiwan. The aim of this longitudinal study was to evaluate the effect of the disruption of circadian rhythms by the shift schedule on menstrual cycle length (MCL) and regularity of female workers at an optoelectronic company in Taiwan. We recruited females who worked rotating shifts in a clean room environment as the shift‐work group and female office workers who worked normal business hours as the comparison group. Every participant recorded their MCL for each menstruation cycle up to eight consecutive months prospectively and provided demographic characteristics, reproductive history, and menstrual characteristics. We collected data on 1,135 and 117 menstruation cycles in the shift‐work (n=280) and comparison groups (n=49). Whereas the two groups had similar group means for MCL and number of menstrual bleeding days, the prevalence of menstrual cycle irregularity (cycles<25 or>35 days) was higher in the shift‐work group (p=0.04). Univariate and multivariate logistic regression analyses demonstrated that rotating shift work was an independent predictor of menstrual cycle irregularity (odds ratio=1.71, 95% confidence interval: 1.03–2.88) after adjusting for shift‐work history, employment duration, coffee consumption, and pre‐employment menstrual cycle irregularity. Although further study is required to confirm our findings plus to explore prevention and control measures, our data indicate rotating shift work can increase the risk of MCL irregularity.