bluuebunny/crossref_metadata_2025 huggingface dataset:
Acclimation to hypothermic incubation in developing chicken embryos(Gallus domesticus)
Authors: Black Juli L. , Burggren Warren W.
Published: March 2004

Hypothermic incubation reduces the ability of the late-stage chicken embryo to mount endothermic heat production. This study investigates whether blood O2 transport is similarly limited by cooler incubation temperatures. Two populations of chicken embryos were incubated at 38°C and 35°C. At Hamilton–Hamburger (HH) developmental stage 41–42, hypothermic incubation had no significant effect on hematocrit(∼26%) or [Hb] (7 g%). However, in the final stages of incubation (stage 43–44), hypothermic incubation reduced hematocrit from ∼31% at 38°C to ∼27.5% at 35°C. Hypothermic incubation similarly caused a reduced [Hb] from 8.5 g% (38°C) to 6.25 g% (35°C), indicating a reduction in blood O2-carrying capacity in embryos. Incubation temperature had a strong effect on blood–O2 affinity in late development (stage 43–44), with P50 at 38°C falling significantly from ∼6 kPa in 38°C embyros to ∼4 kPa in 35°C embryos. PO2 values in chorioallantoic arterial blood at HH 41–42 were 4.3 kPa at pH 7.46 (38°C) and 3.4 kPa at pH 7.39 (35°C). In chorioallantoic venous blood these values were 9.1 kPa at pH 7.34 (38°C) and 8.1 kPa at pH 7.42 (35°C). With further development to HH 43–44, chorioallantoic arterial blood oxygenation fell to 2.4 kPa at pH 7.54 (38°C) and 2.8 kPa at pH 7.52 (35°C). Similarly, PO2 in chorioallantoic venous blood fell slightly to 7.7 kPa at pH 7.42 (38°C) and 7.4 kPa at pH 7.48 (35°C). Collectively, these data reveal that beyond HH 41–42, 35°C embryos experience retarded hematological development, and the findings that support the observed delayed metabolic response to acute temperature changes.
β-naphthoflavone induction of CYP1A in brain of juvenile lake trout(Salvelinus namaycush Walbaum)
Authors: Chung-Davidson Yu-Wen , Rees Christopher B. , Wu Hong , Yun Sang-Seon , Li Weiming
Published: March 2004

Many environmental pollutants induce expression of the cytochrome P450(CYP) 1A subfamily of genes. We integrated cellular and molecular biological techniques to examine the effects of β-naphthoflavone (BNF) exposure in lake trout brain CYP1A distribution and dynamics. Over a 32-day time-course,real time quantitative reverse transcription polymerase chain reaction(Q-RT-PCR) results showed that CYP1A mRNA induction in response to BNF exposure occurred rapidly and continued to rise in the BNF-treated lake trout after 4 h, with a peak at or after 2 days. Messenger RNA levels fell after 4 days, and this trend continued after 16 days of exposure. In situhybridization indicated that CYP1A mRNA was universally elevated in the brain of BNF-exposed fish and was mainly expressed in the endothelia and occasionally in the glial cells. CYP1A immunoreactivity was induced in the olfactory bulb and valvula cerebelli of BNF-treated fish. Other brain areas showed constitutive CYP1A immunoreactivity in both control and BNF-treated fish. Some BNF-treated fish contained multifocal hemorrhages in the brain tissue, and these fish had overall depressed CYP1A immunoreactivity in the brain. The relationship between transcriptional and translational effects of BNF exposure in the brain of juvenile lake trout is discussed.
On the nature of pre-freeze mortality in insects: water balance, ion homeostasis and energy charge in the adults ofPyrrhocoris apterus
Authors: Koštál V. , Vambera J. , Bastl J.
Published: March 2004

Three acclimation groups [i.e. non-diapause (LD), diapause (SD) and diapause, cold-acclimated (SDA)] of the adult bugs Pyrrhocoris apterus differed markedly in their levels of chill tolerance. Survival time at a sub-zero, but non-freezing, temperature of –5°C (Lt50)extended from 7.6 days, through 35.6 days, to >60 days in the LD, SD and SDA insects, respectively. The time necessary for recovery after chill-coma increased linearly with the increasing time of exposure to –5°C, and the steepness of the slope of linear regression decreased in the order LD>SD>SDA. The capacity to prevent/counteract leakage of Na+ down the electrochemical gradient (from haemolymph to tissues) during the exposure to –5°C increased in the order LD<SD<SDA. As a result, the rates of counteractive outward movement of K+, and of the EK dissipation, decreased in the same order. The least chill-tolerant insects (LD) showed the highest rate of body-water loss. Most of the water was lost from the haemolymph compartment. The ability to regulate a certain fraction of ion pools into the hindgut fluid was the highest in the SDA group, medium in the SD group and missing in the LD group. The adenylate energy charge in the fat body cells was constant in all three groups. The total pools of ATP, ADP and AMP, however, decreased in the SD and SDA groups but remained constant in the LD group. The inability of insects to maintain ion gradients at sub-zero temperature is discussed as an important cause of pre-freeze mortality.
Locomotory behaviour and post-exercise physiology in relation to swimming speed, gait transition and metabolism in free-swimming smallmouth bass(Micropterus dolomieu)
Authors: Peake Stephan J. , Farrell Anthony P.
Published: March 2004

We examined swimming behaviour, gait recruitment and post-exercise muscle glycogen, muscle lactate, plasma lactate and oxygen consumption in smallmouth bass (Micropterus dolomieu; 24–38 cm fork length) that voluntarily ascended a 25 m raceway against water velocities ranging from 40 to 120 cm s–1. Physiological parameters were referenced to additional measurements made following exhaustive exercise in a static tank and aerobic exercise in a swim tunnel. Maximum speeds maintained exclusively using a steady gait in the raceway ranged from 53.6 to 97.3 cm s–1 and scaled positively with fish length. Minimum swimming speeds maintained exclusively through recruitment of an unsteady gait were also positively correlated to fish length and ranged from 81.4 to 122.9 cm s–1. Fish switched between steady and unsteady swimming at intermediate speeds. Smallmouth bass always maintained a positive ground speed in the raceway; however, those that primarily swam using a steady gait to overcome low to moderate water velocities (20–50 cm s–1) maintained mean ground speeds of ∼20 cm s–1. By contrast, mean ground speeds of fish that primarily recruited an unsteady locomotory gait increased significantly with water velocity, which resulted in an inverse relationship between exercise intensity and duration. We interpret this behaviour as evidence that unsteady swimming was being fuelled by the limited supply of anaerobic substrates in the white muscle. This hypothesis is supported by the fact that unsteady swimming fish showed significantly lower muscle glycogen levels, higher lactate concentrations (muscle and plasma) and higher post-exercise oxygen consumption rates compared with fish that used a steady gait. The reduction in passage time achieved by fish using an unsteady gait allowed them to ascend the raceway with relatively minor post-exercise metabolic imbalances, relative to individuals chased to exhaustion.
Palladium Catalyzed Aerobic Dehydrogenation: From Alcohols to Indoles and Asymmetric Catalysis
Authors: Stoltz Brian M
Published: March 2004

Catalytic aerobic dehydrogenation of organic substrates is going through a Renaissance. Recent advances in this area have led to the discovery of palladium-catalyzed alcohol dehydrogenations and oxidative hetero- and carbocyclizations. The development of asymmetric catalytic dehydrogenations is the latest advance in a long line of catalytic asymmetric oxidation reactions.
Formation of Luminescent CdTe–Silica Nanoparticles through an Inverse Microemulsion Technique
Authors: Selvan S Tamil , Li Chunliang , Ando Masanori , Murase Norio
Published: March 2004

CdTe quantum dots (QDs, 3–6 nmφ) were incorporated into silica nanoparticles (20–30 nmφ) by an inverse microemulsion technique. The transmission electron microscope image shows that the QDs are situated on the surface of silica particles. These QD-silica particles in solution exhibited a stable luminescence with at least the similar quantum efficiency (ca. 5%) as that of the initial colloidal solution over several weeks of storage. The particles taken out from the solution as a powder form showed the same quantum efficiency for a long time as well. This is because silica acts as an effective protective environment for the QDs.
Synthesis of Model Compound Containing an Indole Spiro-β-lactam Moiety with Vinylchloride in Chartellines
Authors: Nishikawa Toshio , Kajii Shigeo , Isobe Minoru
Published: March 2004

A model compound containing an indole β-lactam moiety bearing vinylchloride in chartellines was synthesized from the Mannich reaction of isatin imine with ketene silyl acetal, β-lactam formation of the resulting β-amino ester, and copper(I)-mediated coupling with (E)-α-chloro-β-iodostyrene.
An Improved Synthesis of Chacotriose
Authors: Lequart Vincent , Goethals Gérard , Banoub Joseph , Villa Pierre , Martin Patrick
Published: March 2004

Glycosylation using the trichloroacetimidate method was investigated in order to synthetize chacotriose. In a continuation of previous studies we present here a shorter approach to the synthesis of chacotriose, α-l-rhamnopyranosyl-(1→2)-[α-l-rhamnopyranosyl-(1→4)]-d-glucopyranose.
Synthesis of 3,3,6,6-Tetraaryl-1,2-Dioxanes via TiO2-catalyzed Photooxygenation of 1,1-Diarylethenes in the Presence of Mg(ClO4)2
Authors: Maeda Hajime , Miyamoto Hisayuki , Mizuno Kazuhiko
Published: March 2004

Photooxygenation of methoxy-substituted 1,1-diarylethenes and 1,1,8,8-tetraaryl-1,7-octadienes catalyzed by titanium dioxide proceeded via photoinduced electron transfer to give 3,3,6,6-tetraaryl-1,2-dioxanes in high yields. The photooxygenation was remarkably accelerated by the addition of Mg(ClO4)2.
An Overview of Some Recent Developments in Ionization Methods for Mass Spectrometry
Authors: Van Berkel Gary J.
Published: March 2004

An overview of some recent advances in ionization sources for mass spectrometry is presented. Limitations were set so that the overview covers ionization techniques relevant to organic and biological analysis that have appeared in the literature since the year 2000. No effort is made to be comprehensive. Rather, a broad sweep overview of author-subjective highlights among a wide variety of sources is presented. These ionization sources include electron ionization, chemical ionization, various atmospheric plasma ionization sources, laser desorption sources, sonic spray and electrospray ionization sources.
Depression of the Apparent Chiral Recognition Ability Obtained in the Host–Guest Complexation Systems by Electrospray and Nano-Electrospray Ionization Mass Spectrometry
Authors: Sawada Masami , Takai Yoshio , Yamada Hitoshi , Yoshikawa Muneyoshi , Arakawa Ryuichi , Tabuchi Hiroyuki , Takada Mikio , Tanaka Jyuichi , Shizuma Motohiro , Yamaoka Hiroshi , Hirose Keiji , Fukuda Kazuo , Tobe Yoshito
Published: March 2004

Chiral recognition in the host–guest complexation systems of chiral crown ether hosts and amino ester guests was thoroughly examined using the electrospray ionization (ESI) mass spectrometry/enantiomer labeled (EL)-guest method. In this method, the mass spectra of a mixture of three components in a solution, a chiral host (H), an equal amount of an ( S)-enantiomer guest labeled with deuterium atoms (GS-dn+) and an unlabeled ( R)-enantiomer guest (G R+), were measured and the relative peak intensity value [ I(H+G R)+ / I(H + GS-dn)+= IRIS] of the host–guest complex ions, observed with an excess guest concentration, was taken to provide the chiral recognition ability of the host. In our earlier report (1996), we demonstrated that the apparent chiral recognition abilities using a mass spectrometer with a homemade ESI interface were depressed by about one tenth compared with the corresponding abilities obtained by fast-atom bombardment (FAB) MS. In the present study, the enantioselective complexation behaviors of various combinations of chiral crown hosts with chiral guests were further investigated in detail mainly using a modern commercial ESI/ion trap (IT) mass spectrometer. Consequently, it was found that the apparent IRIS values from the ESI-MS/EL-guest method changed significantly, depending upon the instrument used, and in particular, upon the ESI interfaces. Moreover, under the specific measuring conditions in ESI-IT-MS, the degrees of depression of the apparent chiral recognition abilities are roughly grouped into three classes, depending upon the number (or probably the type) of the hydrophobic substituents of the hosts. Representing the degrees by the slopes when plotting the apparent IRIS values in ESI-MS versus those in FAB-MS, the slopes for the three classes are (1) 1.0, (2) 0.7 and (3) 0.3; the higher the hydrophobicity of the hosts (and then, the host–guest complex ions), the lower the slope (the apparent enantioselectivity). Strengthening the degree of depression may be caused by an increase in the local concentration of the host close to the surface of the droplets produced during the electrospary ionization process. The chiral recognition ability ( KR/KS) in an equilibrated solution agrees quite well with the IRIS value in FAB-MS rather than that in ESI-MS.
Is Collision-Induced Dissociation of Low-Energy Carbonyl Sulfide Cations Adversely Affected by Asymmetry?
Authors: Shukla Anil K.
Published: March 2004

We have measured relative abundances of fragment ions resulting from collision-induced dissociation of OCS+ ions in collision with xenon neutrals as a function of ion kinetic energy and scattering angle. The lowest energy dissociation product, S+, dominates at all energies up to 53 eV kinetic energy studied here. Surprisingly, the second most abundant dissociation channel is CS+ and not CO+ even though the thermochemical threshold for CO+ is lower than that for CS+ and CO+ is more abundant than CS+ in the normal mass spectrum of OCS. We do not observe any significant abundance of CO+ in this energy range, suggesting that collision-induced excitation and dissociation of OCS+ is significantly different to that of symmetric triatomic ions. A possible role of asymmetry in the molecular ion's collisional activation via neutral collision is suggested for the different behavior.
Energetics and Dynamics of Peptide Fragmentation from Multiple-Collision Activation and Surface-Induced Dissociation Studies
Authors: Laskin Julia
Published: March 2004

This account summarizes the energetics and dynamics of peptide fragmentation obtained using a new approach recently developed in our laboratory. The approach involves RRKM modeling of time- and energy-resolved tandem mass spectrometry (MS/MS) data obtained using collisional activation. We demonstrate that surface-induced dissociation (SID) on a long time-scale of Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) is perfectly suited for studying the energetics and dynamics of peptide fragmentation. The advantages provided by SID include very fast ion activation, which eliminates possible discrimination against higher-energy dissociation pathways, and efficient “amplification” of small changes in dissociation parameters. We present a summary of results obtained for small alanine-containing peptides as well as larger peptides including angiotensin analogs and a series of peptides containing the LDIFSDF motif.
Contact Regions in the Dimer of Alzheimer β-Amyloid Domain [1–28] Studied by Mass Spectrometry
Authors: Li Aiqun , Fenselau Catherine
Published: March 2004

Information is provided about the amino acid residues in the [1–28] domain of the Alzheimer β-amyloid protein, which participate in interstrand pairing and initiate fibillogenesis. The study was carried out using electrospray ionization on a four sector mass spectrometer, measuring kinetic energy release for a fragmentation process, and modeling the transition state with molecular dynamics calculations. The results eliminate the sequence [11–24] proposed earlier as the central core, and are consistent with, but do not distinguish between, residues [17–28] and [17–23] proposed by others based on biochemical studies.
Mitochondrial 3′ tRNA editing in the jakobid Seculamonas ecuadoriensis: A novel mechanism and implications for tRNA processing
Authors: LEIGH JESSICA , LANG B. FRANZ
Published: March 2004

The jakobid flagellates are bacteriovorus protists with mitochondrial genomes that are the most ancestral identified to date, in that they most resemble the genomes of the α-proteobacterial ancestors of the mitochondrion. Because of the bacterial character of jakobid mitochondrial genomes, it was expected that mechanisms for gene expression and RNA structures would be bacterial in nature. However, sequencing of the mitochondrial genome of the jakobid Seculamonas ecuadoriensis revealed several apparent mismatches in the acceptor stems of two predicted tRNAs. To investigate this observation, we determined the cDNA sequences of these tRNAs by RT-PCR. Our results show that the last three positions of the 3′ extremity, plus the discriminator position of seryl and glutamyl tRNAs, are altered posttranscriptionally, restoring orthodox base-pairing and replacing the discriminator with an adenosine residue, in an editing process that resembles that of the metazoan Lithobius forficatus. However, the most 5′ of the edited nucleotides is occasionally left unedited, indicating that the editing mechanism proceeds initially by exonucleolytic degradation, followed by repair of the degraded region. This 3′ tRNA editing mechanism is likely distinct from that of L. forficatus, despite the apparent similarities between the two systems.
The Neurospora crassa CYT-18 protein C-terminal RNA-binding domain helps stabilize interdomain tertiary interactions in group I introns
Authors: CHEN XIN , MOHR GEORG , LAMBOWITZ ALAN M.
Published: March 2004

The Neurospora crassa mitochondrial tyrosyl-tRNA synthetase (CYT-18 protein) promotes the splicing of group I introns by stabilizing the catalytically active RNA structure. To accomplish this, CYT-18 recognizes conserved structural features of group I intron RNAs using regions of the N-terminal nucleotide-binding fold, intermediate α-helical, and C-terminal RNA-binding domains that also function in binding tRNATyr. Curiously, whereas the splicing of the N. crassa mitochondrial large subunit rRNA intron is completely dependent on CYT-18’s C-terminal RNA-binding domain, all other group I introns tested thus far are spliced efficiently by a truncated protein lacking this domain. To investigate the function of the C-terminal domain, we used an Escherichia coli genetic assay to isolate mutants of the Saccharomyces cerevisiae mitochondrial large subunit rRNA and phage T4 td introns that can be spliced in vivo by the wild-type CYT-18 protein, but not by the C-terminally truncated protein. Mutations that result in dependence on CYT-18’s C-terminal domain include those disrupting two long-range GNRA tetraloop/receptor interactions: L2–P8, which helps position the P1 helix containing the 5′-splice site, and L9–P5, which helps establish the correct relative orientation of the P4–P6 and P3–P9 domains of the group I intron catalytic core. Our results indicate that different structural mutations in group I intron RNAs can result in dependence on different regions of CYT-18 for RNA splicing.
Definition of bases in 23S rRNA essential for ribosomal subunit association
Authors: MAIVÄLI ÜLO , REMME JAANUS
Published: March 2004

The ribosome is a two-subunit molecular machine, sporting a working cycle that involves coordinated movements of the subunits. Recent structural studies of the 70S ribosome describe a rather large number of intersubunit contacts, some of which are dynamic during translocation. We set out to determine which intersubunit contacts are functionally indispensable for the association of ribosome subunits by using a modification interference approach. Modification of the N-1 position of A715, A1912, or A1918 inEscherichia coli50S subunits is strongly detrimental to 70S ribosome formation. This result points to 23S rRNA helices 34 and 69, and thus bridges B2a and B4, as essential for ensuring stability of the 70S ribosome.
Mutations in the middle domain of yeast poly(A) polymerase affect interactions with RNA but not ATP
Authors: ZHELKOVSKY ALEXANDER , HELMLING STEFFEN , BOHM ANDREW , MOORE CLAIRE
Published: March 2004

The eukaryotic poly(A) polymerase (PAP) is responsible for the posttranscriptional extension of mRNA 3′ ends by the addition of a poly(A) tract. The recently published three-dimensional structures of yeast and bovine PAPs have made a more directed biochemical analysis of this enzyme possible. Based on these structures, the middle domain of PAP was predicted to interact with ATP. However, in this study, we show that mutations of conserved residues in this domain of yeast PAP, Pap1, do not affect interaction with ATP, but instead disrupt the interaction with RNA and affect the enzyme’s ability to process substrate lacking 2′ hydroxyls at the 3′ end. These results are most consistent with a model in which the middle domain of PAP interacts directly with the recently extended RNA and pyrophosphate byproduct.
Evaluation of Exposure to 2,2‐Dichloro‐1,1,1‐Trifluoroethane (HCFC‐123) in Air‐conditioner Manufacturing Workers and their Health Effects in South Korea
Authors: Shin Yong Chul , Yi Gwang Yong , Kim Tae‐Kyun , Sohn Nam‐Seok , Park Jungsun , Chung Ho‐keun , Yoo Cheolin , Lee Ji Ho , Kim Yangho
Published: March 2004

Evaluation of exposure to 2,2‐Dichloro‐1,1,1‐trifluoroethane (HCFC‐123) in air‐conditioner manufacturing workers and their health effects in South Korea: Yong Chul Shin, et al. Department of Occupational Health and Safety, Inje University—Hepatic dysfunction in workers exposed to HCFC‐123 has recently been reported, but information on the level of exposure to the material and the related hepatotoxicity in workers handling the material is very limited. This study evaluated the exposure status in some Korean workers handling the chemical and whether they have liver dysfunction. We investigated all four factories manufacturing large‐sized industrial air‐conditioners operating in South Korea in 1998. The range and geometric mean of the estimated 8‐hour TWA concentrations at two factories were 2.2 ppm (0.89‐4.2 ppm) and 32.5 ppm (4.9‐113.9 ppm), respectively. It was estimated that the HCFC‐123 concentrations at the other two factories were lower than those at the former two. Liver function was within the normal range in all the exposed workers. The present study did not show any health effect of HCFC‐123 on workers. Worker exposure in this study was intermittent and lower than in studies which reported cases of liver dysfunction, so that the level and pattern of exposure to HCFC‐123 would be very important as a cause of liver dysfunction. Our study showed that liver dysfunction did not occur at an exposure concentration less than 32.5 ppm as an 8‐hour TWA of HCFC‐123.
Excessive Daytime Sleepiness and its Associated Factors among Male Non‐shift White‐collar Workers
Authors: Doi Yuriko , Minowa Masumi , Fujita Toshiharu
Published: March 2004

Excessive Daytime Sleepiness and its Associated Factors among Male Non‐shift White‐collar Workers: Yuriko Doi, et al. Department of Epidemiology, National Institute of Public Health— Excessive daytime sleepiness (EDS) has been noted as a tremendous burden on our modern society and life, but evidence on EDS is limited for white‐collar workers in occupational settings. To estimate the prevalence rate of EDS and examine its associated factors, we investigated 3,909 male non‐shift white‐collar employees aged 20‐59 working in a telecommunications company in the Tokyo metropolitan area between December 1999 and January 2000 (a response rate of 91.0%). Our main findings in the present study were that the prevalence rate of EDS was 7.2% and five factors associated with EDS were identified in a multivariate logistic regression model (p <0.05): nocturnal sleep duration, sleep‐wake schedules, depression, marital status and smoking. These results suggest that the individual behavioral modification of sleep habits and lifestyle is one of the promising strategies for reducing EDS. More importantly, it is possible that occupational and health promotion policies such as a ban on overtime work and the provision of mental health hygiene and social support at worksites are effective for the prevention of EDS in the workplace.
Biological Monitoring of Cadmium Exposed Workers in a Nickel‐Cadmium Battery Factory in China
Authors: Zhang Guicheng , Lindars Elaine , Chao Zeren , Bai Yu , Spickett Jeff
Published: March 2004

Biological Monitoring of Cadmium Exposed Workers in a Nickel‐Cadmium Battery Factory in China: Guicheng Zhang, et al. School of Public Health, Curtin University of Technology—A cross‐sectional study of renal damage in workers from a Chinese Ni‐Cd battery factory is reported in this paper. The present exposure of surveyed workers to Cd may be likened to that of factories in developed countries prior to the 1950s. The results show urinary cadmium did not increase significantly with the years of exposure in aged workers exposed to cadmium. In these occupationally exposed workers urinary cadmium levels of 3 to 60 pg/g creatinine relate to between 15% and 20% of the workers having B2‐MG proteinura, and blood cadmium levels less than 5μg/l relate to more than 10% of the workers having B2‐MG proteinura. The results suggest that a urinary cadmium concentration of 5 pg/g cr or a blood cadmium concentration of 5μg/l would not be a safe level.
Acceptability and Long‐Term Compliance with Drug Treatment for Hypercholesterolemia in Japanese Male Workers: I. Acceptability of Drug Treatment
Authors: Tatemichi Masayuki , Hamaguchi Tsutahiro , Hashira Munetaka , Hayashi Takeshi , Ito Masato , Nakatani Atsushi , Hiro Hisanori , Mori Koji , Ookubo Yasushi , Ezaki Takafumi , Sugimori Hiroki , Yoshida Katsumi , Group S‐LIT Study
Published: March 2004

Acceptability and Long‐Term Compliance with Drug Treatment for Hypercholesterolemia in Japanese Male Workers: 1. Acceptability of Drug Treatment: Masayuki Tatemichi, et al. Department of Environmental and Occupational Health, Toho University School of Medicine—We performed a prospective study to assess the acceptability and long‐ term compliance with drug treatment for hypercholesterolemia in Japanese male workers aged 40 to 57 yr with hypercholesterolemia detected in legally required periodical physical examinations. This paper describes the acceptability of statin‐based drug treatment. All eligible workers who had not improved after 3‐month diet therapy were recommended for drug treatment with simvastatin, a 3 hydroxy‐3‐ methylcoenzyme A reductase inhibitor. Subsequently, according to each individual preference, the subjects were divided to two groups: a group which accepted drug treatment (DT) and a group which rejected it. The subjects who did not accept drug treatment were further assigned to two groups according to their preference: a group which accepted only dietary intervention (Dl) and a non‐treatment group (NT). Among 1,278 workers recruited, 656 (51.3%) were placed in the DT group, 414 (32.4%) in the Dl group and 208 (16.3%) in the NT group. In the DT group, mean serum total cholesterol (TC) was the highest [272 ± 30 (SO) mg/dl]. The acceptability of drug treatment was significantly associated with the serum TC level, pre‐existing medical history of hypertension and a family history of ischemic heart disease (IHO). The occupational issues such as type of job, overtime worked, sleeping time and psychologicalstatus were different among the three groups, and habits of taking breakfast and daily exercise were associated with acceptability of drug treatment. These data suggest that acceptability of the drug treatment is low and associated with the work‐and lifestyle‐ related issues as well as IHO risk factors.
Blood Pressure and Heart Rate Variability in Taxi Drivers on Long Duty Schedules
Authors: Kobayashi Fumio , Watanabe Takemasa , Watanabe Misuzu , Akamatsu Yasuhiro , Tomita Teruyuki , Nakane Taisuke , Furui Hikari , Takeuchi Kiyomi , Okada Akiyoshi , Ohashi Rumi , Hayano Junichiro
Published: March 2004

Blood Pressure and Heart Rate Variability in Taxi Drivers on Long Duty Schedules: Fumio KObayashi, et al. Department of Health and Psychosocial Medicine, Aichi Medical University School of Medicine

Objective

To clarify the mechanisms of excessive risk of cardiovascular disease among taxi drivers, the effects of taxi driving with long work hours on taxi drivers' blood pressure and heart rate variability were examined.

Methods

We measured the physical activity level, ambulatory blood pressure, and Holter ECG in 34 healthy middleaged male taxi drivers over one work day and the two following non‐work days. The subjects worked for a 24‐h period starting at 07:00, then rested from work for 48 h. Ambulatory blood pressure was recorded automatically at 30‐min intervals over the 72‐h period. Holter ECG records were also kept for the 72 h, and temporal changes in the R‐R interval were analyzed by the complex demodulation method (COM). The amplitude of the high frequency (HF) components (central frequency 0.30 Hz), and the ratio of lowfrequency components (central frequency 0.09 Hz) to high‐frequency components (LlH) was calculated.

Results

Blood pressure during the work day was significantly higher than that during the non‐work days, with a stronger effect in the hypertensive subjects. There were no significant overall differences in heart rate variability between the work day and the non‐work days, but the temporal patterns of HF and UH on the work day revealed a potent effect of reversed‐phased circadian rhythm for work at night.

Conclusions

Long duty taxi driving raises blood pressure and may increase cardiovascular risk as a result. The conflict between the circadian rhythms of autonomic nervous activity and work activity at night may also result in increased risk.
Prevalence and Risk Factors of Chronic Liver Disease among Oil Refinery Workers
Authors: Sia Hon‐Ke , Wang Jung‐Der , Huang Chun‐Cheng , Huang Chi‐Hung
Published: March 2004

Prevalence and Risk Factors of Chronic Liver Disease among Oil Refinery Workers: Hon‐Ke SIA, et ale Department of Internal Medicine, Chang‐Hua Christian Hospital—Objectives: The objective of this study was to determine the prevalence and major risk factors of chronic liver diseases among workers in an oil refinery and research factory with ultrasonography as an assessment tool. Methods: After a walk‐through survey in the factory, workers were classified into exposed and non‐exposed groups. Regular health screening data for the past four years were collected and all 700 workers were asked to fill out a questionnaire about their life style. A total of 345 workers voluntarily participated in the study, and 326 of them had abdominal ultrasonography. Results: Fatty liver disease (FLD) was found to be the most common problem (27.9%), followed by hepatitis virus infection (HBsAg positive rate: 18.0%, anti‐HCV positive rate: 2.6%). The major causes of persistent alanine aminotransferase (ALT) increase were FLD and hepatitis virus infection. Obesity was the most important determinant of FLD and hepatitis virus infection was that of parenchymal liver disease (PLD). Modeling by multiple logistic regression model demonstrated that exposure to petroleum distillates or other chemicals in this factory was not associated with FLD, PLD or persistent ALT increase even in workers employed for more than twenty years. Obesity and virus infection did not show a synergistic hepatotoxic effect on solvent exposure probably due to a low level of exposure. Conclusions: Fatty liver and chronic hepatitis B infection were the major chronic liver diseases in oil‐refinery workers in Taiwan, where exposure to hepatotoxic solvents was low.
Exposure Assessment on Volatile Organic Compounds (VOCs) for Tollway Station Workers via Direct and Indirect Approaches
Authors: Lee Ching‐Chang , Chen Mei‐Ru , Shih Tung‐Sheng , Tsai Perng‐Jy , Lai Ching‐Huang , Liou Saou‐Hsing
Published: March 2004

Exposure Assessment on Volatile Organic Compounds (VOCs) for Tollway Station Workers via Direct and Indirect Approaches: Ching‐Chang Lee, et al. Department of Environmental and Occupational Health, Medical College, National Cheng Kung University—The present study was set out to assess the exposure levels of volatile organic compounds (VOCs) for tollway station workers via direct and indirect approaches. For direct approach, personal samplings were conducted on 25, 30 and 31 booth attendants of a tollway station during the dayshift (08:00 AM‐16:00 PM), nightshift (16:00 PM‐24:00 AM), and late‐nightshift (24:00 AM‐08:00 AM), respectively. For each collected sample, five target VOCs including benzene, toluene, xylene, ethylbenzene and methyl tertiary‐butyl ether (MTBE) were analyzed. Results show that at least four of the exposure profiles of the five target VOCs for the booth attendants on any given workshift were log‐normally distributed. The above results suggest that the booth attendants on any given workshift can be regarded as a similar exposure group (SEG). The exposure levels for both the dayshift and the nightshift booth attendants were quite similar, but were significantly higher than those for the late‐ nightshift booth attendants. A similar tend was found in the vehicle flow rates. The above results indicate that the difference in VOC exposure levels for the booth attendants on the three workshifts could be due to the intrinsic difference in the vehicle flow rates. After conducting linear regression analyses, we found that the vehicle flowrates were able to explain the variation in VOC exposure levels up to 40%‐52%. It is concluded that the vehicle flow rates can be used as an indirect indicator for predicting the booth attendants’ VOC exposure levels.
Association between Liver Dysfunction and Hyperglycemia in Japanese Male Workers at Printing and Papermaking Plants
Authors: Kaido Takero , Honda Yasushi , Kitamura Kuniaki
Published: March 2004

Association between Liver Dysfunction and Hyperglycemia in Japanese Male Workers at Printing and Papermaking Plants: Takero Kaido, et al., Osaka Prefecture College of Nursing—This cohort study investigated the association between liver dysfunction and two types of impaired glucose metabolism, i.e., hyperglycemia (HG) and quasi‐ diabetes mellitus (quasi‐DM) (quasi‐DM was treated as a subset of HG). Accordingly, the study consists of a quasi‐DM study and an HG study. Study subjects were middle‐aged male workers at printing and paper‐ making plants who participated in both 1993 and 1997 annual health checkups. In the quasi‐DM study, the number of subjects was 1,422. A logistic regression model revealed that liver dysfunction (AST>40IU/l and/ or ALT>40IU/l and/or GGT>80IU/l) and obesity (BMI>=25 kg/m2) in 1993 were associated with an increased risk of having quasi‐DM in 1997 (odds ratio (OR) for liver dysfunction = 2.1,95% confidence interval (Cl): 1.1‐4.1; OR for obesity = 2.0, 95%CI: 1.0‐4.0). For alcohol intake, the relationship was positive for former drinkers and negative for current drinkers (for former drinkers, OR=2.7, 95%CI: 0.86‐8.6, and for current drinkers, OR=0.39, 95%CI: 0.19‐0.81). Age and smoking status did not show a meaningful association. In the HG study, the number of subjects was 1,254. In an analysis identical to that of the quasi‐ DM study, we found that liver dysfunction and obesity in 1993 was associated with an increased risk of having HG in 1997 (for liver dysfunction, OR=1.8, 95%CI: 1.2‐ 2.7, and for obesity OR=1.6, 95%CI: 1.0‐2.4). These analyses suggest that liver dysfunction can be a predictor of impaired glucose metabolism.
Magnetometric Evaluation for Cytotoxicity of Potassium Octatitanate Whisker on Alveolar Macrophages of Fischer 344 Rats
Authors: Watanabe Mitsuyasu , Shibata Kaori , Okada Mitsushi , Kudo Yuichiro , Niitsuya Masato , Satoh Toshihiko , Kotani Makoto , Aizawa Yoshiharu
Published: March 2004

Magnetometric Evaluation for Cytotoxicity of Potassium Octatitanate Whisker on Alveolar Macrophages of Fischer 344 Rats: Mitsuyasu Watanabe, et al. Department of Preventive Medicine and Public Health, Kitasato University School of Medicine—Alveolar macrophages are thought to play a major role in the pathophysiology of lung diseases caused by exposure to various kinds of pathogens and particles. In the present study, the cytotoxic effect of potassium octatitanate whisker (PT) on macrophages was evaluated by means of magnetometry, lactate dehydrogenase (LDH) release measurement, apoptosis measurement and morphological observations. Alveolar macrophages obtained from Fischer rats (F344/N Sic) by bronchoaiveolar lavage were incubated in vitro for 18 h with Fe3O4 as a magnetometric indicator, and PTs as test materials. In the control group and the group exposed to 10 μg/ml of PT, rapid attenuation of the remanent magnetic field (RMF), so called “relaxation,” was observed immediately after cessation of the external magnetic field. In comparison, a delay of relaxation was observed in alveolar macrophages exposed to 20 and 40 μg/ml of PT. The decay constants, which are calculated from decreasing RMF for the first 2 min, in the groups exposed to 20 and 40 μg/ml of PT had significantly lower values than the control. LDH release induced by exposure to 20 and 40 μg/ml of PT increased significantly in a concentration dependent manner in PT‐exposed macrophages, whereas only negligible LDH release was observed in control groups. The level of PT affecting alveolar macrophages was at the same concentration, and in a dose‐dependent manner among relaxation, decay constant and LDH measurement. A DNA ladder detection method and morphological observations detected no apoptosis in PT‐exposed macrophages. Electron microscopic examination revealed vacuolar changes and cell membrane damage in PT‐exposed macrophages, but no significant changes in control macrophages. The results of magnetometry, LDH release, apoptosis measurement and electron microscopic observations suggest concentration dependent cytotoxicity caused by exposure of alveolar macrophages to PT.
Urinary Excretion of Mercury from Mice Exposed to Metallic Mercury Vapor Determined with NTA Complex
Authors: Aikoh Hiromi , Tagawa Chie , Shibahara Takashi
Published: March 2004

Urinary Excretion of Mercury from Mice Exposed to Metallic Mercury Vapor Using NTA Complex: Hiromi Aikoh, et al. Department of Chemistry, Faculty of Science, Okayama University of Science—Urinary excretion of mercury was determined in mice exposed to mercury vapor by using the incomplete cubane‐type sulfur‐bridged molybdenum complex [Mo3S4(Hnta)3]2‐ (referred to as the NTA complex). Mice exposed to metallic mercury vapor quickly excreted the mercury in their urine after being given the NTA complex solution. The cumulative amount of mercury in the urine of these mice was 1.3 times higher than that in mice that had received L‐ cysteine and 1.8 times higher than that in mice that had received water. The study revealed that the NTA complex is capable of promoting extra‐corporeal excretion of mercury that had been bodily absorbed by mice.
Childhood Immunisation Recall in Swiss Employees
Authors: Schilling Julian , Duvoisin Nicole , Lee Chung‐Yol , Naguel Claudine , Gyurech Danielle , Gutzwiller Felix
Published: March 2004

Childhood Immunisation Recall in Swiss Employees: Julian Schilling, et al. Institute of Social and Preventive Medicine, University of Zurich—During the workplace health promotion project “Check Bus”, we asked 10,321 employees (4,070 women, 6,251 men, mean age=39 yr) of two nationwide Swiss enterprises, a large bank and an industrial company, about their vaccination status by using a self‐administered questionnaire. Among all respondents, 43.8% reported having a valid (up to date) tetanus vaccination (<10 years old), 29.9% a pertussis vaccination, 74.2% a poliomyelitis vaccination, 53.8% a tuberculosis vaccination, 22.7% a rubella vaccination and 12.7% an MMR vaccination (measles, mumps, rubella). A large number of respondents had no knowledge of their personal immunisation status. We found significant socio‐demographic differences. For all vaccinations, age, gender (with the exception of MMR) and language independently predicted vaccination status. Hierarchic occupational rank was an independent and significant predictor for pertussis, poliomyelitis and tuberculosis vaccinations. Our study showed that especially elderly people, males and Italian speaking participants had a very limited knowledge of their personal vaccination status.
Distribution of Inhaled m‐Xylene in Rat Brain and its Effect on GAB AA Receptor Binding
Authors: Ito Takehiko , Yoshitome Kei , Horike Tokushi , Kira Shohei
Published: March 2004

Distribution of Inhaled m‐Xylene in Rat Brain and its Effect on GAB Aa Receptor Binding: Takehiko Ito, et al. Faculty of Education, Okayama University—Organic solvents generally depress the central nervous system (CNS), similarly to volatile anesthetics. The precise mechanism of their action on the CNS, however, is not fully understood, and remains to be clarified. This study is focused on how inhaled m‐xylene distributes in the brain, and whether region specific change in GAB Aa receptor binding takes place due to the exposure. To conduct this study, we first developed a simple exposure system suitable for inhalation experiments with small animals. Using this system, six‐week‐old male Sprague‐Dawley rats were exposed to m‐xylene vapor (2000 ppm) 4 h/d, for 5 consecutive days. At the end of the exposure, m‐xylene levels in four different regions of the brain were measured by head‐space gas chromatography. Also 14μm‐thick frozen sections of the brain were made, and [35S] t‐butylbicyclophosphorothionate (TBPS) binding autoradiography was performed. Uneven distribution of m‐xylene in the brain was observed. The concentration in the cerebellum (976 ± 93.4μg/g tissue) was the highest, while that in the cerebral cortex (467 ± 43.6μ/g tissue) was the lowest. [35S]TBPS binding was significantly greater in the molecular layer of the cerebellum (control: 12.6 ± 0.64, m‐xylene 16.0 ± 1.34 fmol/mg tissue). These results suggest that m‐xylene is distributed unevenly in the rat brain, and acute exposure to m‐xylene at a high concentration alters PSJTBPS binding, which may reflect changes in GABAA receptor characteristics.
Effect of Acute Exposure to Loud Occupational Noise during Daytime on the Nocturnal Sleep Architecture, Heart Rate, and Cortisol Secretion in Healthy Volunteers
Authors: Gitanjali Batmanabane , Ananth Ramachandran
Published: March 2004

Effect of Acute Exposure to Loud Occupational Noise during Daytime on the Nocturnal Sleep Architecture, Heart Rate, and Cortisol Secretion in Healthy Volunteers: Batmanabane Gitanjali, et al. Department of Pharmacology, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), India

Objectives

Noise is one of the commonest physical stressors to which industrial workers are exposed. Many workers complain of symptoms associated with a non‐specific generalized stress response, including disturbed sleep. However, industrial workers may be exposed to more than one source of stress and it is not possible to completely attribute the disturbed nocturnal sleep and changes in heart rate to the effects of loud noise alone. This study was done to find out whether acute exposure of healthy individuals to loud occupational noise during the daytime would cause changes in their nocturnal sleep architecture, heart rate during sleep and serum cortisol levels.

Methods

Baseline polysomnography was done on ten subjects who were exposed for eight hours either to continuous occupational background noise levels of >75dB(A), or a quiet environment. Sleep polysomnography was done on the night prior to and after exposure. Blood was collected for serum cortisol estimation at night prior to sleep and in the morning after waking up. Statistical analysis was done by repeated measures ANOVA with Tukey's post test.

Results

The sleep efficiency was less than 80% and the total time spent in Rapid Eye Movement (REM) sleep, Slow Wave Sleep (SWS) and the REM onset latency were significantly decreased on the night after exposure to noise. There was a significant increase in stage shifts. The percentage fall in heart rate during sleep was decreased compared to the baseline values. The serum cortisol levels in the morning after exposure to noise was significantly increased.

Conclusion

Workers exposed to loud background occupational noise react to the stress and show changes in nocturnal sleep architecture and heart rate which may be contributed to the exposure to noise.
Effects of Genetic Polymorphisms in Metabolic Enzymes on the Relationships between 8‐hydroxydeoxyguanosine Levels in Human Leukocytes and Urinary 1‐hydroxypyrene and 2‐naphthol Concentrations
Authors: Kim Yong‐Dae , Lee Chul‐Ho , Nan Hong‐Mei , Kang Jong‐Won , Kim Heon
Published: March 2004

Effects of Genetic Polymorphisms in Metabolic Enzymes on the Relationships between 8‐hydroxydeoxyguanosine Levels in Human Leukocytes and Urinary 1‐hydroxypyrene and 2‐naphthol Concentrations: Yong‐Dae Kim, et al. Department of Preventive Medicine, College of Medicine, Chungbuk National University, South Korea—This study was designed to investigate the relationship between environmental exposure to polycyclic aromatic hydrocarbons (PAHs) and oxidative stress, and to evaluate the effects of cigarette smoking and the genetic polymorphisms of CYP1A1, CYP2E1, GSTM1, NAT2 and UGT1A6 on the relationship. The subjects of this study were 105 healthy Korean males without occupational exposure to PAHs. The 8‐hydroxydeoxyguanosine (8‐OHdG) level in leukocytes, and urinary 1‐hydroxypyrene (1‐OHP) and 2‐naphthol concentrations, were measured by high‐performance liquid chromatography. Genetic polymorphisms of CYP1A1, CYP2E1, GSTM1, NAT2 and UGT1A6 were identified by PCR and PCR‐RFLP methods. The 8‐OHdG level showed a significant correlation with the 1‐OHP concentration in all subjects (p< .001) and in smokers (p< .01), and with the 2‐naphthol level in nonsmokers (p< .01). The 8‐OHdG level was significantly higher in smoking rapid acetylators than in smoking slow or intermediate acetylators, and in individuals with the UGT1A6 wild‐type than in those with the UGT1A6 mutant genotype. Significant positive correlations between 8‐OHdG and 1‐OHP concentrations were found in subjects with every genotype of the CYP1A1 and CYP2E1 genes, with the GSTM1 null‐type, with the NAT2 genotype of a rapid acetylator, and with the UGT1A6 wild‐type, respectively. The urinary 2‐naphthol level significantly correlated with the 8‐OHdG level only in subjects with the GSTM1 null‐type. In conclusion, there is a significant correlation between the 8‐OHdG level in leukocytes and the urinary 1‐OHP concentration in the population not occupationally exposed to PAHs. This relationship is affected by genetic polymorphisms in PAH metabolic enzymes.
Simple Hydrothermal Synthesis of Nanostructured and Nanorod Zn–Al Complex Oxides as Novel Nanocatalysts
Authors: Shen S. C. , Hidajat K. , Yu L. E. , Kawi S.
Published: March 2004

Nanoparticles of Zn–Al complex oxides (see Figure) have been successfully synthesized in large quantities using a simple hydrothermal process without a surfactant. When these nanomaterials with high surface areas are used as the catalyst for selective reduction of NOx, they show high activity, thermal/hydrothermal stability, and high selectivity to N2. The results indicate good potential for application of these new nanomaterials as environmental catalysts.
From Hollow to Dense Spheres: Control of Dipolar Interactions by Tailoring the Architecture in Colloidal Aggregates of Superparamagnetic Iron Oxide Nanocrystals
Authors: Tartaj P. , González‐Carreño T. , Serna C. J.
Published: March 2004

The synthesis of spherical colloidal aggregates (see Figure) of superparamagnetic iron oxide nanocrystals with different packing fractions is reported. Using a mean‐field model, the magnitude of dipolar interactions between nanomagnets has been correlated with differences in their assembly. The results could help understanding of the magnetic behavior of magnetic liposomes and hollow capsules, which are promising for drug delivery.