bluuebunny/crossref_metadata_2025 huggingface dataset:
Spontaneous Cytokine Production and Its Effect on Induced Production
Authors: Walker Derrick , Jason Janine , Wallace Kelly , Slaughter Justin , Whatley Virginia , Han Alison , Nwanyanwu Okey C. , Kazembe Peter N. , Dobbie Hamish , Archibald Lennox , Jarvis William R.
Published: August 2002

Cytokines regulate cellular immune activity and are produced by a variety of cells, especially lymphocytes, monocytes, and macrophages. Multiparameter flow cytometry is often used to examine cell-specific cytokine production after in vitro phorbol 12-myristate 13-acetate and ionomycin induction, with brefeldin A or other agents added to inhibit protein secretion. Spontaneous ex vivo production reportedly rarely occurs. We examined the spontaneous production of interleukin 2 (IL-2), IL-4, IL-6, IL-8, IL-10, tumor necrosis factor alpha (TNF-α), and gamma interferon (IFN-γ) by peripheral-blood B lymphocytes, T cells, CD8
−
T cells, CD8
+
T cells, CD3
−
CD16/56
+
lymphocytes (natural killer [NK] cells), CD3
+
CD16/56
+
lymphocytes (natural T [NT] cells), and/or monocytes of 316 acutely ill hospitalized persons and 62 healthy adults in Malawi, Africa. We also evaluated the relationship between spontaneous and induced cytokine production. In patients, spontaneous TNF-α production occurred most frequently, followed in descending order by IFN-γ, IL-8, IL-4, IL-10, IL-6, and IL-2. Various cells of 60 patients spontaneously produced TNF-α; for 12 of these patients, TNF-α was the only cytokine produced spontaneously. Spontaneous cytokine production was most frequent in the immunoregulatory cells, NK and NT. For IL-2, IL-4, IL-6, IL-8, and IL-10, spontaneous cytokine production was associated with greater induced production. For TNF-α and IFN-γ, the relationships varied by cell type. For healthy adults, IL-6 was the cytokine most often produced spontaneously. Spontaneous cytokine production was not unusual in these acutely ill and healthy persons living in an area where human immunodeficiency virus, mycobacterial, malaria, and assorted parasitic infections are endemic. In such populations, spontaneous, as well as induced, cell-specific cytokine production should be measured and evaluated in relation to various disease states.
Use of Egg Yolk-Derived Immunoglobulin as an Alternative to Antibiotic Treatment for Control of
Helicobacter pylori
Infection
Authors: Shin Ji-Hyun , Yang Mierha , Nam Seung Woo , Kim Jung Taik , Myung Na Hye , Bang Won-Gi , Roe Im Hwan
Published: August 2002

The present study evaluated the potential use of immunoglobulin prepared from the egg yolk of hens immunized with
Helicobacter pylori
(immunoglobulin Y [IgY]-Hp) in the treatment of
H. pylori
infections. The purity of our purified IgY-Hp was 91.3%, with a yield of 9.4 mg of IgY per ml of egg yolk. The titer for IgY-Hp was 16 times higher than that for IgY in egg yolk from nonimmunized hens, and IgY-Hp significantly inhibited the growth and urease activity of
H. pylori
in vitro. Bacterial adhesion on AGS cells was definitely reduced by preincubation of both
H. pylori
(10
8
CFU/ml) and 10 mg of IgY-Hp/ml. In Mongolian gerbil models, IgY-Hp decreased
H. pylori
-induced gastric mucosal injury as determined by the degree of lymphocyte and neutrophil infiltration. Therefore, in this experimental model,
H. pylori
-associated gastritis could be successfully treated by orally administered IgY-Hp. The immunological activity of IgY-Hp stayed active at 60°C for 10 min, suggesting that pasteurization can be applied to sterilize the product. Fortification of food products with this immunoglobulin would significantly decrease the
H. pylori
infection. In conclusion, the IgY-Hp obtained from hens immunized by
H. pylori
could provide a novel alternative approach to treatment of
H. pylori
infection.
Immunoglobulin G Antibody Response to Infection with Coccoid Forms of
Helicobacter pylori
Authors: Figueroa G. , Faúndez G. , Troncoso M. , Navarrete P. , Toledo M. S.
Published: August 2002

An increasing number of studies support a potential role for coccoid forms in
Helicobacter pylori
infection. Evidence for this was obtained through scanning microscopy, genetic analysis for virulence traits, examination of the presence and activity of key enzymes, and other methods. We studied the serum immunoglobulin G responses to coccoid
H. pylori
forms by enzyme-linked immunosorbent assay (ELISA) and immunoblotting and compared them with those of bacillary cells. Sera from a total of 295 infected individuals were studied; these included sera from 100 patients with duodenal ulcers, 98 patients with nonulcer dyspepsia, 11 patients with gastroduodenal cancer, and 86 asymptomatic individuals. Initially, we characterized and selected coccoid and bacillary antigenic preparations by one-dimensional (1-D) and 2-D gel electrophoresis and immunoblotting. Data showed that coccoid and bacillary preparations with comparable protein contents have similar patterns in 1-D and 2-D electrophoresis gels and antigenic recognition at blotting. These results revealed that coccoid and spiral antigens in ELISA can equally recognize specific antibodies to
H. pylori
in sera from infected individuals. The analysis of the spiral and coccoid preparations by Western blotting showed no major differences in antigen recognition. No specific bands or profiles associated with a single gastric condition were identified.
Clinical and Epidemiological Relevance of Quantitating Hepatitis E Virus-Specific Immunoglobulin M
Authors: Seriwatana Jitvimol , Shrestha Mrigendra P. , Scott Robert M. , Tsarev Sergei A. , Vaughn David W. , Myint Khin Saw Aye , Innis Bruce L.
Published: August 2002

Diagnosis of acute hepatitis E by detection of hepatitis E virus (HEV)-specific immunoglobulin M (IgM) is an established procedure. We investigated whether quantitation of HEV IgM and its ratio to HEV total Ig furnished more information than conventional IgM tests that are interpreted as positive or negative. A previously described indirect immunoassay for total Ig against a baculovirus-expressed HEV capsid protein was modified to quantitate HEV-specific IgM in Walter Reed (WR) antibody units by using a reference antiserum and the four-parameter logistic model. A receiver-operating characteristics curve derived from 197 true-positive specimens and 449 true-negative specimens identified 30 WR units/ml as an optimum cut point. The median HEV IgM level in 36 patients with acute hepatitis E fell from 3,000 to 100 WR units/ml over 6 months, suggesting that 100 WR units/ml would be a more appropriate cut point for distinguishing recent from remote IgM responses. Among three hepatitis E case series, determination of the HEV IgM-to-total-Ig ratio in acute-phase serum revealed that most patients had high ratios consistent with primary infections whereas a few had low ratios, suggesting that they had sustained reinfections that elicited anamnestic antibody responses. The diagnostic utility of the new IgM test was similar to that of a commercially available test that uses different HEV antigens. In conclusion, we found that HEV IgM can be detected specifically in >95% of acute hepatitis E cases defined by detection of the virus genome in serum and that quantitation of HEV IgM and its ratio to total Ig provides insight into infection timing and prior immunity.
Cytokine Gene Expression by Peripheral Blood Leukocytes in Horses Experimentally Infected withAnaplasma phagocytophila
Authors: Kim Hyung-Yong , Mott Jason , Zhi Ning , Tajima Tomoko , Rikihisa Yasuko
Published: August 2002

Human granulocytic ehrlichiosis (HGE), a tick-borne zoonosis, is caused by an obligatory intragranulocytic bacterium, the HGE agent, a strain ofAnaplasma phagocytophila. The equine model of HGE is considered valuable in understanding pathogenic and immune mechanisms of HGE. In the present study, cytokine mRNA expression by peripheral blood leukocytes (PBLs) in horses was examined during the course of infection by intravenous inoculation ofA. phagocytophilaor by allowing feeding by infected ticks. Thep44genes encoding the major outer membrane protein P44s ofA. phagocytophilawere detected by PCR in PBLs of all four horses from 4 to 20 days postexposure. During the 20-day infection period, interleukin-1β (IL-1β) and tumor necrosis factor alpha (TNF-α) mRNA expression was upregulated in PBLs of all four horses, and IL-8 mRNA expression was upregulated in three horses. Gamma interferon, IL-10, and IL-12 p35 mRNAs were weakly expressed in only one horse each. IL-2, IL-4, IL-6, and IL-12 p40 mRNA expression , however, could not be detected in the PBLs of any of the four horses. These results suggest that IL-1β, TNF-α, and IL-8 generation duringA. phagocytophilainfection has a primary role in HGE pathogenesis and immunomodulation.
Gamma Interferon Inhibits Production of Anti-OspA Borreliacidal Antibody In Vitro
Authors: Munson Erik L. , Du Chateau Brian K. , Jensen Jani R. , Callister Steven M. , DeCoster David J. , Schell Ronald F.
Published: August 2002

The ability of a Lyme borreliosis vaccine to induce and maintain sustained levels of borreliacidal antibody is necessary for prolonged protection against infection withBorrelia burgdorferi. Vaccination against infection withB. burgdorfericould be improved by determining the mechanism(s) that influences the production of protective borreliacidal antibody. Borreliacidal antibody was inhibited in cultures of lymph node cells obtained from C3H/HeJ mice vaccinated with formalin-inactivatedB. burgdorferiand cultured with macrophages andB. burgdorferiand treated with recombinant gamma interferon (rIFN-γ). The suppression of production of outer surface protein A (OspA) borreliacidal antibody by rIFN-γ was not affected by the time of treatment. In addition, treatment with rIFN-γ inhibited the production of other anti-B. burgdorferiantibodies. By contrast, treatment of cultures of immune lymph node cells with anti-IFN-γ marginally increased the production of borreliacidal antibody and enhanced the production of other antibodies directed againstB. burgdorferi. These results show that IFN-γ does not play a major role in the production of anti-OspA borreliacidal antibody. Additional studies are needed to determine which cytokine(s) will enhance production of borreliacidal antibody.
Suppression of Growth by All-
trans
Retinoic Acid Requires Prolonged Induction of Interferon Regulatory Factor 1 in Cervical Squamous Carcinoma (SiHa) Cells
Authors: Arany Istvan , Whitehead William E. , Grattendick Kenneth J. , Ember Istvan A. , Tyring Stephen K.
Published: August 2002

All-
trans
retinoic acid (ATRA) suppresses growth of cervical dysplasias in vivo, although the sensitivity to retinoids is frequently lost during cervical carcinogenesis. It has been suggested that prolonged treatment or use of higher doses of retinoids might offer favorable response rates. We found SiHa cervical squamous carcinoma cells that were virtually resistant to ATRA-induced growth-inhibitory effects at physiological doses (10
−7 to
10
−6
M) to be more responsive at pharmacological doses (10
−5 to
10
−4
M). The growth inhibition by high-dose (10
−4
M) ATRA was associated with a sustained activation of interferon regulatory factor 1 (IRF-1), while a low dose (10
−6
M) of ATRA activated IRF-1 only transiently. Antisense IRF-1 inhibited the high-dose (10
−4
M), ATRA-mediated growth arrest; forced expression of IRF-1 caused a significant reduction in cell growth. High-dose (10
−4
M) ATRA increased binding of NF-κB and STAT1 proteins to sequences that originated from the IRF-1 promoter region, while low-dose (10
−6
M) ATRA induced only NF-κB binding. A delayed tyrosine phosphorylation of the signal transducer and activator of transcription-1 (STAT1) was observed after high-dose (10
−4
M) but not low-dose (10
−6
M) ATRA treatment. In agreement with this, induction of IRF-1 mRNA by ATRA was only modest and transient in a STAT1 knockout cell line, suggesting the importance of STAT1 in sustained IRF-1 expression. Our data showed that ATRA is capable of inducing dose-dependent cellular changes, which might be appropriate to overcome resistance to retinoids that frequently develops during cervical carcinogenesis.
Performance of Two Commercial Glycoprotein G-Based Enzyme Immunoassays for Detecting Antibodies to Herpes Simplex Viruses 1 and 2 in Children and Young Adolescents
Authors: Leach Charles T. , Ashley Rhoda L. , Baillargeon Jacques , Jenson Hal B.
Published: August 2002

In 61 patients 1 to 14 years of age, the Gull/Meridian enzyme-linked immunosorbent assay (ELISA) had a sensitivity of 100% for herpes simplex virus type 1 (HSV-1) and specificities of 74% for HSV-1 and 48% for HSV-2. In 128 similarly aged patients, the HerpeSelect ELISA (Focus Technologies) showed sensitivities of 80% for HSV-1 and 88% for HSV-2, and specificities of 97% for HSV-1 and 100% for HSV-2.
Determination of the Nucleotide Sequences of Heat Shock Operon
groESL
and the Citrate Synthase Gene (
gltA
) of
Anaplasma
(
Ehrlichia
)
platys
for Phylogenetic and Diagnostic Studies
Authors: Inokuma Hisashi , Fujii Kaori , Okuda Masaru , Onishi Takafumi , Beaufils Jean-Pierre , Raoult Didier , Brouqui Philippe
Published: August 2002

The 1,670-bp nucleotide sequence of the heat shock operon
groESL
and the 1,236-bp sequence of the citrate synthase gene (
gltA
) of
Anaplasma
(
Ehrlichia
)
platys
were determined. The topology of the
groEL
- and
gltA
-based phylogenetic tree was similar to that derived from 16S rRNA gene analyses with distances. Both
groESL
- and
gltA
-based PCRs specific to
A. platys
were also developed based upon the alignment data.
Diagnostic Techniques To Detect Cryptic Leishmaniasis in Dogs
Authors: Iniesta Laura , Fernández-Barredo Salceda , Bulle Béatrice , Gómez M. Teresa , Piarroux Renaud , Gállego Montserrat , Alunda José M. , Portús Montserrat
Published: August 2002

This study of several techniques for detecting cryptic leishmaniasis in dogs from areas in Spain where
Leishmania infantum
is highly endemic concludes that immunological techniques (enzyme-linked immunosorbent assay, immunofluorescence antibody test, Western blotting, delayed-type hypersensitivity reaction, and in vitro lymphocyte proliferation assay) do not clearly differentiate between noninfected and infected asymptomatic dogs and that culture and PCR are more reliable diagnostic tools.
Active Surveillance for Scrapie by Third Eyelid Biopsy and Genetic Susceptibility Testing of Flocks of Sheep in Wyoming
Authors: O'Rourke Katherine I. , Duncan John V. , Logan James R. , Anderson Anne K. , Norden Dianne K. , Williams Elizabeth S. , Combs Bret A. , Stobart Robert H. , Moss Gary E. , Sutton Diane L.
Published: August 2002

Control of scrapie, an ovine transmissible spongiform encephalopathy or prion disorder, has been hampered by the lack of conventional antemortem diagnostic tests. Currently, scrapie is diagnosed by postmortem examination of the brain and lymphoid tissues for PrPSc, the protein marker for this group of disorders. For live, asymptomatic sheep, diagnosis using tonsil or third-eyelid lymphoid tissue biopsy and PrPScassay has been described. To evaluate the feasibility and efficacy of third-eyelid testing for identification of infected flocks and individual infected sheep, 690 sheep from 22 flocks were sampled by third-eyelid lymphoid tissue biopsy and immunohistochemistry. Sheep were further evaluated for relative genetic susceptibility and potential contact exposure to scrapie. Third-eyelid testing yielded suitable samples for 80% of the sheep tested, with a mean of 18.1 lymphoid follicles (germinal centers) per histologic section. Three hundred eleven of the sheep were sampled through passive surveillance programs, in which only sheep with potential contact with an infected sheep at a lambing event were tested, regardless of their scrapie susceptibility genotype. In addition, 141 genetically susceptible sheep with no record of contact with an infected animal at a lambing event were sampled through a targeted active surveillance program. Ten PrPSc-positive sheep were identified through the passive surveillance program, and an additional three PrPSc-positive sheep, including two from flocks with no history of scrapie, were identified through the active surveillance program. All PrPSc-positive sheep had the highly susceptible PrP genotype. Third-eyelid testing is a useful adjunct to flock monitoring programs, slaughter surveillance, and mandatory disease reporting in a comprehensive scrapie eradication and research program.
Augmentation of the Lipopolysaccharide-Neutralizing Activities of Human Cathelicidin CAP18/LL-37-Derived Antimicrobial Peptides by Replacement with Hydrophobic and Cationic Amino Acid Residues
Authors: Nagaoka Isao , Hirota Satoko , Niyonsaba François , Hirata Michimasa , Adachi Yoshiyuki , Tamura Hiroshi , Tanaka Shigenori , Heumann Didier
Published: August 2002

Mammalian myeloid and epithelial cells express various peptide antibiotics (such as defensins and cathelicidins) that contribute to the innate host defense against invading microorganisms. Among these peptides, human cathelicidin CAP18/LL-37 (L1to S37) possesses not only potent antibacterial activity against gram-positive and gram-negative bacteria but also the ability to bind to gram-negative lipopolysaccharide (LPS) and neutralize its biological activities. In this study, to develop peptide derivatives with improved LPS-neutralizing activities, we utilized an 18-mer peptide (K15to V32) of LL-37 as a template and evaluated the activities of modified peptides by using the CD14+murine macrophage cell line RAW 264.7 and the murine endotoxin shock model. By replacement of E16and K25with two L residues, the hydrophobicity of the peptide (18-mer LL) was increased, and by further replacement of Q22, D26, and N30with three K residues, the cationicity of the peptide (18-mer LLKKK) was enhanced. Among peptide derivatives, 18-mer LLKKK displayed the most powerful LPS-neutralizing activity: it was most potent at binding to LPS, inhibiting the interaction between LPS and LPS-binding protein, and attaching to the CD14 molecule, thereby suppressing the binding of LPS to CD14+cells and attenuating production of tumor necrosis factor alpha (TNF-α) by these cells. Furthermore, in the murine endotoxin shock model, 18-mer LLKKK most effectively suppressed LPS-induced TNF-α production and protected mice from lethal endotoxin shock. Together, these observations indicate that the LPS-neutralizing activities of the amphipathic human CAP18/LL-37-derived 18-mer peptide can be augmented by modifying its hydrophobicity and cationicity, and that 18-mer LLKKK is the most potent of the peptide derivatives, with therapeutic potential for gram-negative bacterial endotoxin shock.
Impaired Macrophage Phagocytosis of Apoptotic Neutrophils in Patients with Human Immunodeficiency Virus Type 1 Infection
Authors: Torre Donato , Gennero Luisa , Baccino F. M. , Speranza Filippo , Biondi Gilberto , Pugliese Agostino
Published: August 2002

Dysfunction of neutrophils (polymorphonuclear leukocytes [PMNL]) and macrophagic cells occurs as a consequence of human immunodeficiency virus type 1 (HIV-1) infection. Macrophages contribute to the resolution of early inflammation ingesting PMNL apoptotic bodies. This study investigated macrophage ability to phagocytose PMNL apoptotic bodies in patients with HIV-1 infection in comparison with uninfected individuals and the effect of HIV Nef protein on apoptotic body phagocytosis to determine if phagocytic activity is impaired by HIV infection. Monocytes/macrophages were isolated from 10 HIV-1-infected patients and from five healthy volunteers, whereas PMNL were isolated from healthy volunteers. Macrophage phagocytosis of apoptotic PMNL was determined by staining of apoptotic bodies with fluorescein-conjugated concanavalin A or with fluorescein-labeled phalloidin. Our data show significant impairment of PMNL apoptotic body macrophage phagocytosis in subjects with HIV-1 infection presenting a concentration of CD4+T lymphocytes of >200/mm3and in particular in those with <200 CD4+T lymphocyte cells/mm3. In addition, HIV-1 recombinant Nef protein is able to decrease phagocytosis of apoptotic PMNL from normal human macrophages in a dose-dependent manner. The results of our study suggest that impaired macrophage phagocytosis of PMNL apoptotic bodies may contribute to the persistence of the inflammatory state in HIV-infected subjects, especially during opportunistic infections that are often favored by defective phagocytic activity.
Occupational exposure assessment in case–control studies: opportunities for improvement
Authors: Teschke K , Olshan A F , Daniels J L , De Roos A J , Parks C G , Schulz M , Vaughan T L
Published: August 2002

Community based case–control studies are an efficient means to study disease aetiologies, and may be the only practical means to investigate rare diseases. However, exposure assessment remains problematic. We review the literature on the validity and reliability of common case–control exposure assessment methods: occupational histories, job–exposure matrices (JEMs), self reported exposures, and expert assessments. Given the variable quality of current exposure assessment techniques, we suggest methods to improve assessments, including the incorporation of hygiene measurements: using data from administrative exposure databases; using results of studies identifying determinants of exposure to develop questionnaires; and where reasonable given latency and biological half life considerations, directly measuring exposures of study subjects.
Work organisation and unintentional sleep: results from the WOLF study
Authors: Åkerstedt T , Knutsson A , Westerholm P , Theorell T , Alfredsson L , Kecklund G
Published: August 2002

Background:Falling asleep at work is receiving increasing attention as a cause of work accidents.

Aims:To investigate which variables (related to work, lifestyle, or background) are related to the tendency to fall asleep unintentionally, either during work hours, or during leisure time.

Methods:5589 individuals (76% response rate) responded to a questionnaire. A multiple logistic regression analysis of the cross sectional data was used to estimate the risk of falling asleep.

Results:The prevalence for falling asleep unintentionally at least once a month was 7.0% during work hours and 23.1% during leisure time. The risk of unintentional sleep at work was related to disturbed sleep, having shift work, and higher socioeconomic group. Being older, being a woman, and being a smoker were associated with a reduced risk of unintentionally falling asleep at work. Work demands, decision latitude at work, physical load, sedentary work, solitary work, extra work, and overtime work were not related to falling asleep at work. Removing “disturbed sleep” as a predictor did not change the odds ratios of the other predictors in any significant way. With respect to falling asleep during leisure time, disturbed sleep, snoring, high work demands, being a smoker, not exercising, and higher age (>45 years) became risk indicators.

Conclusion:The risk of involuntary sleep at work is increased in connection with disturbed sleep but also with night work, socioeconomic group, low age, being a male, and being a non-smoker.
Validity of empirical models of exposure in asphalt paving
Authors: Burstyn I , Boffetta P , Burr G A , Cenni A , Knecht U , Sciarra G , Kromhout H
Published: August 2002

Aims:To investigate the validity of empirical models of exposure to bitumen fume and benzo(a)pyrene, developed for a historical cohort study of asphalt paving in Western Europe.

Methods:Validity was evaluated using data from the USA, Italy, and Germany not used to develop the original models. Correlation between observed and predicted exposures was examined. Bias and precision were estimated.

Results:Models were imprecise. Furthermore, predicted bitumen fume exposures tended to be lower (−70%) than concentrations found during paving in the USA. This apparent bias might be attributed to differences between Western European and USA paving practices. Evaluation of the validity of the benzo(a)pyrene exposure model revealed a similar to expected effect of re-paving and a larger than expected effect of tar use. Overall, benzo(a)pyrene models underestimated exposures by 51%.

Conclusions:Possible bias as a result of underestimation of the impact of coal tar on benzo(a)pyrene exposure levels must be explored in sensitivity analysis of the exposure–response relation. Validation of the models, albeit limited, increased our confidence in their applicability to exposure assessment in the historical cohort study of cancer risk among asphalt workers.
Urinary bisphenol A and plasma hormone concentrations in male workers exposed to bisphenol A diglycidyl ether and mixed organic solvents
Authors: Hanaoka T , Kawamura N , Hara K , Tsugane S
Published: August 2002

Aims:To evaluate effects of exposure to bisphenol A diglycidyl ether (BADGE) on urinary excretion of bisphenol A, and plasma gonadotrophic hormones and testosterone in male epoxy resin sprayers.

Methods:Cross sectional study of 42 workers whose job was to spray epoxy resin hardening agents including BADGE and mixed organic solvents, and 42 matched control workers without BADGE use in the same machine plants.

Results:Concentrations of urinary bisphenol A were higher in the epoxy resin sprayers (median 1.06 μmol/mol creatinine) compared with the controls (median 0.52 μmol/mol creatinine). Urinary metabolite concentrations of organic solvents used were all higher in the epoxy resin workers compared with the controls. Endocrinological examination showed different concentrations of follicle stimulating hormone (FSH) between the epoxy sprayers (median 5.3 mIU/ml) and the controls (median 7.6 mIU/ml). FSH showed a mild correlation with urinary bisphenol A, but not with the metabolites of organic solvents. Luteinising hormone and free testosterone concentrations did not differ between the two groups.

Conclusion:BADGE may generate bisphenol A endogenously. Results suggest that bisphenol A may disrupt secretion of gonadotrophic hormones in men. The clinical significance of endocrine disrupting effects by bisphenol A should be further investigated in male workers exposed to bisphenol A.
Occupational exposure to noise and the attributable burden of hearing difficulties in Great Britain
Authors: Palmer K T , Griffin M J , Syddall H E , Davis A , Pannett B , Coggon D
Published: August 2002

Aims:To determine the prevalence of self reported hearing difficulties and tinnitus in working aged people from the general population, and to estimate the risks from occupational exposure to noise and the number of attributable cases nationally.

Methods:A questionnaire was mailed to 22 194 adults of working age selected at random from the age–sex registers of 34 British general practices (21 201 subjects) and from the central pay records of the British armed services (993 subjects). Information was collected on years of employment in a noisy job; and whether the respondent wore a hearing aid, had difficulty in hearing conversation, or had experienced persistent tinnitus over the past year. Associations of hearing difficulty and tinnitus with noise exposure were examined by logistic regression, with adjustment for age, sex, smoking habits, and frequent complaints of headaches, tiredness, or stress. The findings were expressed as prevalence ratios (PRs) with associated 95% confidence intervals (CIs). Attributable numbers were calculated from the relevant PRs and an estimate of the prevalence of occupational exposure to noise nationally.

Results:Some 2% of subjects reported severe hearing difficulties (wearing a hearing aid or having great difficulty in both ears in hearing conversation in a quiet room). In men, the prevalence of this outcome rose steeply with age, from below 1% in those aged 16–24 years to 8% in those aged 55–64. The pattern was similar in women, but severe hearing loss was only about half as prevalent in the oldest age band. Tinnitus was far more common in subjects with hearing difficulties. In both sexes, after adjustment for age, the risk of severe hearing difficulty and persistent tinnitus rose with years spent in a noisy job. In men older than 35 years with 10 or more years of exposure, the PR for severe hearing difficulty was 3.8 (95% CI 2.4 to 6.2) and that for persistent tinnitus 2.6 (95% CI 2.0 to 3.4) in comparison with those who had never had a noisy job. Nationally, some 153 000 men and 26 000 women aged 35–64 years were estimated to have severe hearing difficulties attributable to noise at work. For persistent tinnitus the corresponding numbers were 266 000 and 84 000.

Conclusions:Significant hearing difficulties and tinnitus are quite common in men from the older working age range. Both are strongly associated with years spent in a noisy occupation—a predominantly male exposure. The national burden of hearing difficulties attributable to noise at work is substantial.
Raynaud's phenomenon, vibration induced white finger, and difficulties in hearing: Table 1
Authors: Palmer K T , Griffin M J , Syddall H E , Pannett B , Cooper C , Coggon D
Published: August 2002

Background:An association has previously been reported between finger blanching and hearing difficulties, but only in workers with exposure to noise and hand transmitted vibration (HTV).

Aims:To explore the association in a community sample, including cases who lacked occupational exposure to noise or HTV.

Method:A questionnaire was mailed to 12 606 subjects aged 35–64 years, chosen at random from the age–sex registers of 34 British general practices. Inquiry was made about years of employment in noisy jobs, lifetime exposure to HTV, hearing difficulties and tinnitus, and lifetime history of cold induced finger blanching. Subjects were classed as having severe hearing difficulty if they used a hearing aid or found it difficult or impossible to hear conversation in a quiet room. Associations of finger blanching with hearing difficulties and tinnitus were analysed by logistic regression.

Results:Among 8193 respondents were 185 who reported severe hearing difficulty and 1151 who reported finger blanching. After adjustment for age and years of work in noisy jobs, hearing difficulty was about twice as common in men and women who reported finger blanching, including those who had never been importantly exposed to noise and in those never exposed to HTV.

Conclusions:These data support an association between finger blanching and hearing loss, which is not explained by confounding occupational exposure to noise, and suggest that it may extend to causes of blanching other than vibration induced white finger. Further investigations are warranted to confirm the association and explore possible mechanisms, such as sympathetic vasoconstriction in the cochlea.
Chrysotile and tremolite asbestos fibres in the lungs and parietal pleura of Corsican goats
Authors: Dumortier P , Rey F , Viallat J R , Broucke I , Boutin C , De Vuyst P
Published: August 2002

Background and Aims:Environmental exposures to chrysotile and tremolite from the soil cause pleural plaques and mesothelioma in northeast Corsica. Goats grazing in the contaminated areas inhale asbestos fibres. We used this natural animal model to study whether these exposures actually result in increased fibre burdens in the lungs and parietal pleura.

Methods:Ten goats from areas with asbestos outcrops and two from other areas were slaughtered. Fibre content of lung and parietal pleural samples was determined by analytical transmission electron microscopy.

Results:Both chrysotile and tremolite fibres were detected. In the exposed goats, the geometric mean concentrations of asbestos fibres longer than 1 μm were 0.27 × 106fibres/g dry lung tissue and 1.8 × 106fibres/g dry pleural tissue. Asbestos fibres were not detected in the lungs of the two control goats. Chrysotile fibres shorter than 5 μm were predominant in the parietal pleura. Tremolite fibres accounted for 78% and 86% of the fibres longer than 5 μm in lung and parietal pleural samples, respectively.

Conclusions:Environmental exposure in northeast Corsica results in detectable chrysotile and tremolite fibre loads in the lung and parietal pleura of adult goats. Tremolite fibres of dimensions with a high carcinogenic potency are detected in the parietal pleura.
BOSONIC CENTRAL LIMIT THEOREM FOR THE ONE-DIMENSIONAL XY MODEL
Authors: MATSUI TAKU
Published: August 2002

We prove the central limit theorem for Gibbs states and ground states of quasifree Fermions (bilinear Hamiltonians) and those of the off critical XY model on a one-dimensional integer lattice.
APPROXIMATELY INNER FLOWS ON SEPARABLE C*-ALGEBRAS
Authors: KISHIMOTO AKITAKA
Published: August 2002

We present two types of result for approximately inner one-parameter automorphism groups (referred to as AI flows hereafter) of separable C*-algebras. First, if there is an irreducible representation π of a separable C*-algebra A such that π(A) does not contain non-zero compact operators, then there is an AI flow α such that π is α-covariant and α is far from uniformly continuous in the sense that α induces a flow on π(A) which has full Connes spectrum. Second, if α is an AI flow on a separable C*-algebra A and π is an α-covariant irreducible representation, then we can choose a sequence (hn) of self-adjoint elements in A such that αt is the limit of inner flows Ad eithn and the sequence π(eithn) of one-parameter unitary groups (referred to as unitary flows hereafter) converges to a unitary flow which implements α in π. This latter result will be extended to cover the case of weakly inner type I representations. In passing we shall also show that if two representations of a separable simple C*-algebra on a separable Hilbert space generate the same von Neumann algebra of type I, then there is an approximately inner automorphism which sends one into the other up to equivalence.
FUSION RULES OF MODULAR INVARIANTS
Authors: EVANS DAVID E.
Published: August 2002

Modular invariants satisfy remarkable fusion rules. Let Z be a modular invariant associated to a braided subfactor N ⊂ M. The decomposition of the non-normalized modular invariants ZZ* and Z*Z into sums of normalized modular invariants is related to the decomposition of the full induced M-M system of sectors.
MODULAR LOCALIZATION AND WIGNER PARTICLES
Authors: BRUNETTI R. , GUIDO D. , LONGO R.
Published: August 2002

We propose a framework for the free field construction of algebras of local observables which uses as an input the Bisognano–Wichmann relations and a representation of the Poincaré group on the one-particle Hilbert space. The abstract real Hilbert subspace version of the Tomita–Takesaki theory enables us to bypass some limitations of the Wigner formalism by introducing an intrinsic spacetime localization. Our approach works also for continuous spin representations to which we associate a net of von Neumann algebras on spacelike cones with the Reeh–Schlieder property. The positivity of the energy in the representation turns out to be equivalent to the isotony of the net, in the spirit of Borchers theorem. Our procedure extends to other spacetimes homogeneous under a group of geometric transformations as in the case of conformal symmetries and of de Sitter spacetime.
A REMARK ON QUANTUM GROUP ACTIONS AND NUCLEARITY
Authors: DOPLICHER S. , LONGO R. , ROBERTS J. E. , ZSIDÓ L.
Published: August 2002

Let H be a compact quantum group with faithful Haar measure and bounded counit. If α is an action of H on a C*- algebra A, we show that A is nuclear if and only if the fixed-point subalgebra Aα is nuclear. As a consequence H is a nuclear C*-algebra.
QUANTUM 'ax + b' GROUP
Authors: WORONOWICZ S. L. , ZAKRZEWSKI S.
Published: August 2002

'ax + b' is the group of affine transformations of the real line R. In quantum version ab = q2ba, where q2 = e-i ℏ is a number of modulus 1. The main problem of constructing quantum deformation of this group on the C*-level consists in non-selfadjointness of Δ(b) = a ⊗ b + b ⊗ I. This problem is overcome by introducing (in addition to a and b) a new generator β commuting with a and anticommuting with b. β (or more precisely β ⊗ β) is used to select a suitable selfadjoint extension of a ⊗ b + b ⊗ I. Furthermore we have to assume that [Formula: see text], where k = 0,1,2, ·. In this case, q is a root of 1.

To construct the group, we write an explicit formula for the Kac–Takesaki operator W. It is shown that W is a manageable multiplicative unitary in the sense of [3,19]. Then using the general theory we construct a C*-algebra A and a comultiplication Δ ∈ Mor (A,A ⊗ A). A should be interpreted as the algebra of all continuous functions vanishing at infinity on quantum 'ax + b'-group. The group structure is encoded by Δ. The existence of coinverse also follows from the general theory [19].
REMARKS ON TIME-ENERGY UNCERTAINTY RELATIONS
Authors: BRUNETTI ROMEO , FREDENHAGEN KLAUS
Published: August 2002

Using a recent construction of observables characterizing the time of occurence of an effect in quantum theory, we present a rigorous derivation of the standard time-energy uncertainty relation. In addition, we prove an uncertainty relation for time measurements alone.
KMS, ETC.
Authors: BIRKE LOTHAR , FRÖHLICH JÜRG
Published: August 2002

A general form of the "Wick rotation", starting from imaginary-time Green functions of quantum-mechanical systems in thermal equilibrium at positive temperature, is established. Extending work of H. Araki, the rôle of the KMS condition and of an associated anti-unitary symmetry operation, the "modular conjugation", in constructing analytic continuations of Green functions from real- to imaginary times, and back, is clarified.

The relationship between the KMS condition for the vacuum with respect to Lorentz boosts, on one hand, and the spin-statistics connection and the PCT theorem, on the other hand, in local, relativistic quantum field theory is recalled.

General results on the reconstruction of local quantum theories in various non-trivial gravitational backgrounds from "Euclidian amplitudes" are presented. In particular, a general form of the KMS condition is proposed and applied, e.g., to the Unruh- and the Hawking effects.
ON HAHN–BANACH TYPE THEOREMS FOR HILBERT C*-MODULES
Authors: FRANK MICHAEL
Published: August 2002

We establish three Hahn–Banach type extension criteria for (sets of) bounded C*-linear maps of Hilbert C*-modules to the underlying C*-algebras of coefficients. One criterion gives an alternative description of the property of C*-algebras to be monotone complete or additively complete.
ON THE GROWTH OF HOLOMORPHIC PROJECTIVE FOLIATIONS
Authors: AZEVEDO SCÁRDUA B. C. , CANILLE MARTINS J. C.
Published: August 2002

In the theory of real (non-singular) foliations, the study of the growth of the leaves has proved to be useful in the comprehension of the global dynamics as the existence of compact leaves and exceptional minimal sets. In this paper we are interested in the complex version of some of these basic results. A natural question is the following: What can be said of a codimension one (possibly singular) holomorphic foliation on a compact hermitian manifold M exhibiting subexponential growth for the leaves? One of the first examples comes when we consider the Fubini–Study metric on [Formula: see text] and dimension one foliations. In this case, under some non-degeneracy hypothesis on the singularities, we may classify the foliation as a linear logarithmic foliation. In particular, the limit set of ℱ is a union of singularities and invariant algebraic curves. Applications of this and other results we prove are given to the general problem of uniformization of the leaves of projective foliations.
PT-SYMMETRIC SQUARE WELL AND THE ASSOCIATED SUSY HIERARCHIES
Authors: BAGCHI B. , MALLIK S. , QUESNE C.
Published: August 2002

The PT-symmetric square well problem is considered in a SUSY framework. When the coupling strength Z lies below the critical value [Formula: see text] where PT symmetry becomes spontaneously broken, we find a hierarchy of SUSY partner potentials, depicting an unbroken SUSY situation and reducing to the family of sec 2-like potentials in the Z → 0 limit. For Z above [Formula: see text], there is a rich diversity of SUSY hierarchies, including some with PT-symmetry breaking and some with partial PT-symmetry restoration.
ANGULAR INFLATION FROM SUPERGRAVITY
Authors: GERMÁN G. , MAZUMDAR ANUPAM , PÉREZ-LORENZANA A.
Published: August 2002

We study supergravity inflationary models where inflation is produced along the angular direction. For this we express the scalar component of a chiral superfield in terms of the radial and the angular components. We then express the supergravity potential in a form particularly simple for calculations involving polynomial expressions for the superpotential and Kähler potential. We show for a simple Polonyi model the angular direction may give rise to a stage of inflation when the radial field is fixed to its minimum. We obtain analytical expressions for all the relevant inflationary quantities and discuss the possibility of supersymmetry breaking in the radial direction while inflating by the angular component.
STRUCTURES IN A MAGNETIC SUSPENSION SUBJECTED TO UNIDIRECTIONAL AND ROTATING FIELD
Authors: CARLETTO P. , BOSSIS G. , CEBERS A.
Published: August 2002

Field induced structures are studied inside suspensions of magnetic colloidal particles of micronic size. We have characterized the average distance between aggregates in a thin cell with the magnetic field perpendicular to the plane and also in the presence of a rotating field with the plane of rotation perpendicular to the plane of the cell. The characteristic size of the mesostructure is predicted on the basis of a thermodynamic model. The theory well predicts the experimental results in the uniaxial case but not in the case of ae rotating field; in this last case, the surface tension which is needed to have a good fit is far too low compared to its expected order of magnitude. When the field is uniaxial and sinusoidal we have found a collective instability where all the aggregates are rotating simultaneously in a chaotic way.
CHAIN ROTATIONAL DYNAMICS IN MR SUSPENSIONS
Authors: MELLE SONIA , CALDERÓN OSCAR G. , RUBIO MIGUEL A. , FULLER GERALD G.
Published: August 2002

The dynamics of induced dipolar chains in magnetorhelogical suspensions subject to rotating magnetic fields has been experimentally studied combining scattering dichroism and video microscopy experiments. When a rotating field is imposed the chainlike aggregates rotate synchronously with the magnetic field. We found that the average size of the aggregates decreases with Mason number (ratio of viscous to magnetic forces) following a power law with exponent -0.5 being the hydrodynamic friction forces the cause of the chains break up. However the total number of aggregated particles shows two different behaviors depending on Mason number. For low Mason numbers, the total number of aggregated particles remains almost constant and above a critical Mason number, the rotation of the field prevents the particle aggregation process from taking place so the number of aggregated particles decreases with Mason number following a power law behavior with exponent -1. Athermal molecular dynamics simulations are also reported, showing good agreement with the experiments.
MONODISPERSE COLLOIDAL SUSPENSIONS OF SILICA AND PMMA SPHERES AS MODEL ELECTRORHEOLOGICAL FLUIDS: A REAL-SPACE STUDY OF STRUCTURE FORMATION
Authors: YETHIRAJ ANAND , VAN BLAADEREN ALFONS
Published: August 2002

Colloidal particle coordinates in three dimensions can be obtained in 3D samples with a combination of the increased resolution and optical sectioning capabilities of confocal microscopy and fluorescently labeled model core-shell silica colloids. In this work we show how this capability can be used to analyze structure formation in electrorheological fluids on a quantitative basis. We find body-centered-tetragonal (BCT) crystals for colloidal particles in an electric field. Metastable sheet like structures were identified as an intermediate phase prior to BCT crystal formation. Due to finite-size effects induced by the electrode surface the sheets are not randomly oriented, but grow preferentially with a 60° tilt with respect to the electric field. Preliminary measurements indicate that flow-aligned sheets form under shear. Finally, we show that in the case that the ionic strength is very low, electric-field-induced dipolar interactions can be present in addition to long-range repulsions between the colloids leading to interesting metastable and equilibrium structures with possibilities for applications in photonic bandgap crystals as well as in model ER studies.
POLARIZATION OF NON-EQUILIBRIUM DOUBLE LAYER AND AGGLOMERATION OF POLYELECTROLYTE BALLS
Authors: CEBERS A. , RUBINSTEIN I.
Published: August 2002

Non-equilibrium polarizability of a polyelectrolyte ball is calculated in the frame-work of a quasi-onedimensional model, taking into account the concentration polarization phenomenon. This non-equilibrium polarizability is shown to be proportional to the volume of a polyball and to have a negative sign. Based on these results, the available experimental data to the aggregation phenomena in DNA solutions are considered in terms of the electric field induced phase separation. Numerical estimates for the critical electric field strength necessary for the aggregation to take place and the frequency range where it is observed are in a reasonable agreement with experiment. In the framework of this model, the internal circulations observed in the DNA aggregates are interpreted as being due to the spontaneous rotation of polyelectrolyte balls with a negative polarizability.
HEXAGON-STRIPE TRANSITION AT THE MAGNETIC FIELD INDUCED PHASE TRANSFORMATIONS OF THE MAGNETORHEOLOGICAL SUSPENSIONS
Authors: CEBERS A.
Published: August 2002

The phase diagram of the magnetorheological suspension allowing for the modulated phases in the Hele-Shaw cell under the action of the normal field is calculated. The phase boundaries between the stripe, the hexagonal and the unmodulated phases in dependence on the layer thickness and the magnetic field strength are found. The existence of the transitions between the stripe and the hexagonal phases at the corresponding variation of the physical parameters is illustrated by the numerical simulation of the concentration dynamics in the Hele-Shaw cell. It is remarked that those transitions in the case of the magnetorheological suspensions can be caused by the compression or the expansion of the layer. Among the features noticed at the numerical simulation of the concentration dynamics in the Hele-Shaw cell are: the stripe patterns formed from the preexisting hexagonal structures are more ordered than arising from the initial randomly perturbed state; at the slightly perturbed boundary between the concentrated and diluted phases the hexagonal and the inverted hexagonal phases are formed and others.
EQUILIBRIUM PATTERNS OF CHAIN CLUSTERS COMPOSED OF FERROMAGNETIC PARTICLES IN AN EXTERNAL MAGNETIC FIELD
Authors: UKAI TOMOFUMI , MAEKAWA TORU , MORIMOTO HISAO
Published: August 2002

We carry out Monte Carlo simulations of a ferromagnetic colloidal system, which is subjected to an external magnetic field, to investigate the structures formed by chain clusters. The control parameters are the ratio of the dipole moment energy to thermal energy, λ, and the ratio of the interactive energy between the dipole and the external magnetic field to thermal energy, ξ. We investigate the effect of the system height on the pattern formations for λ=18 and ξ=30, ∞. Note that the system becomes paramagnetic when ξ=∞. We find that as the system height increases, chains coagulate to form fat clusters and spatially ordered structures are created when ξ=30, whereas chains form thin meandering walls when ξ=∞.