bluuebunny/crossref_metadata_2025 huggingface dataset:
Regulation of Membrane Permeability by a Two-Component Regulatory System in
Pseudomonas aeruginosa
Authors: Wang Yanping , Ha Unhwan , Zeng Lin , Jin Shouguang
Published: December 2002

Membrane impermeability is the major contributing factor to multidrug resistance in clinical isolates of
Pseudomonas aeruginosa
. By using laboratory strain PAK, a spontaneous
P. aeruginosa
mutant (mutant PAK1-3) whose membrane had reduced permeability and which displayed increased levels of resistance to various antibiotics, especially aminoglycosides, was isolated. By complementation of the mutant with a genomic clone library derived from wild-type strain PAK, a novel two-component regulatory system (PprA and PprB) was identified and was found to be able to increase the permeability of the bacterial membrane and render PAK1-3 sensitive to antibiotics. Furthermore, specific phosphorylation of the response regulator (PprB) by histidine kinase (PprA) was observed in vitro, demonstrating that they are cognate two-component regulatory genes. Introduction of a plasmid expressing the
pprB
gene into randomly chosen clinical isolates (
n
= 17) resulted in increased sensitivity to aminoglycosides in the majority of isolates (
n
= 13) tested. This is the first demonstration that
P. aeruginosa
membrane permeability can be regulated, providing an important clue in the understanding of the mechanism of membrane impermeability-mediated multidrug resistance in
P. aeruginosa
.
The effectiveness of current approaches to workplace stress management in the nursing profession: an evidence based literature review
Authors: Mimura C , Griffiths P
Published: December 2002

The effectiveness of current approaches to workplace stress management for nurses was assessed through a systematic review. Seven randomised controlled trials and three prospective cohort studies assessing the effectiveness of a stress management programmes were identified and reviewed. The quality of research identified was weak. There is more evidence for the effectiveness of programmes based on providing personal support than environmental management to reduce stressors. However, since the number and quality of studies is low, the question as to which, if any, approach is more effective cannot be answered definitively. Further research is required before clear recommendations for the use of particular interventions for nursing work related stress can be made.
Dose-response patterns for vibration-induced white finger
Authors: Griffin M J , Bovenzi M , Nelson C M
Published: December 2002

Aims:To investigate alternative relations between cumulative exposures to hand-transmitted vibration (taking account of vibration magnitude, lifetime exposure duration, and frequency of vibration) and the development of white finger (Raynaud’s phenomenon).

Methods:Three previous studies have been combined to provide a group of 1557 users of powered vibratory tools in seven occupational subgroups: stone grinders, stone carvers, quarry drillers, dockyard caulkers, dockyard boilermakers, dockyard painters, and forest workers. The estimated total operating duration in hours was thus obtained for each subject, for each tool, and for all tools combined. From the vibration magnitudes and exposure durations, seven alternative measurements of cumulative exposure were calculated for each subject, using expressions of the form: dose = ∑amiti, whereaiis the acceleration magnitude on tooli,tiis the lifetime exposure duration for tooli, andm= 0, 1, 2, or 4.

Results:For all seven alternative dose measures, an increase in dose was associated with a significant increase in the occurrence of vibration-induced white finger, after adjustment for age and smoking. However, dose measures with high powers of acceleration (m> 1) faired less well than measures in which the weighted or unweighted acceleration, and lifetime exposure duration, were given equal weight (m= 1). Dose determined solely by the lifetime exposure duration (without consideration of the vibration magnitude) gave better predictions than measures withmgreater than unity. All measures of dose calculated from the unweighted acceleration gave better predictions than the equivalent dose measures using acceleration frequency-weighted according to current standards.

Conclusions:Since the total duration of exposure does not discriminate between exposures accumulated over the day and those accumulated over years, a linear relation between vibration magnitude and exposure duration seems appropriate for predicting the occurrence of vibration-induced white finger. Poorer predictions were obtained when the currently recommended frequency weighting was employed than when accelerations at all frequencies were given equal weight. Findings suggest that improvements are possible to both the frequency weighting and the time dependency used to predict the development of vibration-induced white finger in current standards.
Organisational justice and health of employees: prospective cohort study
Authors: Kivimäki M , Elovainio M , Vahtera J , Ferrie J E
Published: December 2002

Aims:To examine the association between components of organisational justice (that is, justice of decision making procedures and interpersonal treatment) and health of employees.

Methods:The Poisson regression analyses of recorded all-cause sickness absences with medical certificate and the logistic regression analyses of minor psychiatric morbidity, as assessed by the General Health Questionnaire, and poor self rated health status were based on a cohort of 416 male and 3357 female employees working during 1998–2000 in 10 hospitals in Finland.

Results:Low versus high justice of decision making procedures was associated with a 41% higher risk of sickness absence in men (rate ratio (RR) 1.4, 95% confidence interval (CI) 1.1 to 1.8), and a 12% higher risk in women (RR 1.1, 95% CI 1.0 to 1.2) after adjustment for baseline characteristics. The corresponding odds ratios (OR) for minor psychiatric morbidity were 1.6 (95% CI 1.0 to 2.6) in men and 1.4 (95% CI 1.2 to 1.7) in women, and for self rated health 1.4 in both sexes. In interpersonal treatment, low justice increased the risk of sickness absence (RR 1.3 (95% CI 1.0 to 1.6) and RR 1.2 (95% CI 1.2 to 1.3) in men and women respectively), and minor psychiatric morbidity (OR 1.2 in both sexes). These figures largely persisted after control for other risk factors (for example, job control, workload, social support, and hostility) and they were replicated in initially healthy subcohorts. No evidence was found to support the hypothesis that organisational justice would represent a consequence of health (reversed causality).

Conclusions:This is the first longitudinal study to show that the extent to which people are treated with justice in workplaces independently predicts their health.
Update of predictions of mortality from pleural mesothelioma in the Netherlands
Authors: Segura O , Burdorf A , Looman C
Published: December 2002

Aims:To predict the expected number of pleural mesothelioma deaths in the Netherlands from 2000 to 2028 and to study the effect of main uncertainties in the modelling technique.

Methods:Through an age-period-cohort modelling technique, age specific mortality rates and cohort relative risks by year of birth were calculated from the mortality of pleural mesothelioma in 1969–98. Numbers of death for both sexes were predicted for 2000 to 2028, taking into account the most likely demographic development. In a sensitivity analysis the relative deviation of the future death toll and peak death number were studied under different birth cohort risk assumptions.

Results:The age-cohort model on mortality 1969–98 among men showed the highest age specific death rates in the oldest age group (79 per 100 000 person-years in the age group 80–84 years) and the highest relative risks for the birth cohorts of 1938–42 and 1943–47. Among men a small period effect was observed. The age-cohort model was considered the best model for predicting future mortality. The most plausible scenario predicts an increase in pleural mesothelioma mortality up to 490 cases per year in men, with a total death toll close to 12 400 cases during 2000–28. However, using different assumptions this death toll could rise to nearly 15 000 in men (20% increase). Mortality among women remains low, with a total death toll of about 800 cases. It is predicted that the total death toll in the period 2000–28 is 44% lower than previous predictions using mortality data from 1969 to 1993.

Conclusion:Adding five recent years of observed mortality in an age-cohort model resulted in a 44% lower prediction of the future death toll of pleural mesothelioma. A statistically significant period effect was observed, possibly influenced by initial asbestos safety guidelines in the 1970s and introduction of the ICD-10 codification.
Combined effect of smoking and occupational exposure to noise on hearing loss in steel factory workers
Authors: Mizoue T , Miyamoto T , Shimizu T
Published: December 2002

Background:Evidence has accumulated concerning the adverse effects of smoking on hearing acuity, but it is not clear whether smoking modifies the association between exposure to noise and hearing loss.

Aims:To examine the synergistic effect of these variables on hearing.

Methods:Data used were derived from periodic health examinations for 4624 steel company workers in Japan and included audiometry testing and information on smoking habits. Occupational exposure to noise was determined based on company records. Logistic regression was used to examine the dose-response association between smoking and hearing loss. The Cochran-Mantel-Haenszel method was used to calculate the prevalence rate ratio (PRR) of hearing loss for each combination of smoking and noise exposure factors, taking non-smokers not exposed to occupational noise as a reference. The interaction between smoking and noise exposure was assessed using a synergistic index, which equals 1 when the joint effect is additive.

Results:Smoking was associated with increased odds of having high frequency hearing loss in a dose-response manner. The PRR for high frequency hearing loss among smokers exposed to occupational noise was 2.56 (95% CI 2.12 to 3.07), while the PRR for smokers not exposed to noise was 1.57 (95% CI 1.31 to 1.89) and the PRR for non-smokers exposed to noise was 1.77 (95% CI 1.36 to 2.30). The synergistic index was 1.16. Smoking was not associated with low frequency hearing loss.

Conclusions:Smoking may be a risk factor for high frequency hearing loss, and its combined effect on hearing with exposure to occupational noise is additive.
Periportal fibrosis and other liver ultrasonography findings in vinyl chloride workers
Authors: Maroni M , Mocci F , Visentin S , Preti G , Fanetti A C
Published: December 2002

Aims:To investigate the presence of liver lesions and their relation with vinyl chloride monomer (VCM) exposure or other personal risk factors, in workers involved in the production of VCM and polyvinyl chloride (PVC).

Methods:A liver ultrasonography examination was conducted in 757 workers, some of whom had long standing service in the production of VCM and PVC. The study involved: assessment of individual past and present VCM exposure of each worker; collection of past personal health history, lifestyle and personal data; routine liver function tests; and liver ultrasonography.

Results:No cases of liver malignancies were detected. Angiomas and liver cysts were found with a frequency of occurrence within the expected range of the general population. The main findings consisted of hepatomegaly (34.7%), steatosis (31.8%), and periportal fibrosis (16.0%). A logistic regression analysis indicated that hepatomegaly and steatosis were associated with obesity and lipid metabolism disturbances and not with VCM exposure. Periportal fibrosis, in addition to constitutional or dietary factors, was shown to be associated with VCM exposure, but only when maximum exposure in the subject’s history had been at least 200 ppm as a yearly average; no effects were observed at 50 ppm or below.

Conclusions:Workers exposed to 200 ppm VCM for at least one year have a fourfold increased risk of developing periportal liver fibrosis. Liver ultrasonography is a suitable and important diagnostic test for the medical surveillance of vinyl chloride workers.
Multiple sclerosis in nurse anaesthetists: Table 1
Authors: Flodin U , Landtblom A-M , Axelson O
Published: December 2002

Background:Volatile anaesthetics are chemically related to organic solvents used in industry. Exposure to industrial solvents may increase the incidence of multiple sclerosis (MS).

Aim:To examine the risk among nurse anaesthetists of contracting MS.

Methods:Nurses with MS were identified by an appeal in the monthly magazine of the Swedish Nurse Union and a magazine of the Neurological Patients Association in Sweden. Ninety nurses with MS responded and contacted our clinic. They were given a questionnaire, which was filled in by 85 subjects; 13 of these were nurse anaesthetists. The questionnaire requested information about work tasks, exposure, diagnosis, symptoms, and year. The number of active nurse anaesthetists was estimated based on information from the National Board of Health and Welfare and The Nurse Union. Incidence data for women in the region of Gothenburg and Denmark were used as the reference to estimate the risk by calculation of the standardised incidence ratio (SIR).

Results:Eleven of the 13 nurse anaesthetists were exposed to anaesthetic gases before onset of MS. Mean duration of exposure before diagnosis was 14.4 years (range 4–27 years). Ten cases were diagnosed in the study period 1980–99, resulting in significantly increased SIRs of 2.9 and 2.8 with the Gothenburg and the Danish reference data, respectively.

Conclusion:Although based on crude data and a somewhat approximate analysis, this study provides preliminary evidence for an excess risk of MS in nurse anaesthetists. The risk may be even greater than observed, as the case ascertainment might have been incomplete because of the crude method applied. Further studies in this respect are clearly required to more definitely assess the risk.
Visual and ocular changes associated with exposure to two tertiary amines
Authors: Page E H , Cook C K , Hater M A , Mueller C A , Grote A A , Mortimer V D
Published: December 2002

Aims:To determine if exposure to dimethylisopropanolamine (DMIPA) and dimethylaminoethanol (DMAE) in a label printing plant was associated with visual disturbances and/or ocular changes.

Methods:Questionnaires, eye examinations (visual acuity, contrast sensitivity at 2.5% and 1.25% contrast, slit lamp biomicroscopy, and pachymetry), and industrial hygiene monitoring for DMIPA and DMAE were performed over a two week period.

Results:Eighty nine per cent of line workers reported having experienced blurry vision while at work in the past 12 months, compared to 12.5% of prime workers. A total of 108 full shift personal breathing zone (PBZ) air samples for the amines were collected. The mean time weighted average (TWA) concentration of DMIPA was significantly higher in the line division than in the prime division, as was the mean TWA concentration for total amines. The mean TWA concentration of DMAE was higher in the prime division than the line division. Higher levels of total amines were associated with increased risk of reporting blurry vision, halo vision, and blue-grey vision. The risk of corneal opacity rose with increasing exposure to total amines. The prevalence of corneal opacity also increased with increasing concentration of total amines. Median corneal thickness increased with increasing grades of corneal opacity. There was a statistically significant relation between total amine concentration and increased risk of reduced bilateral visual acuity and 2.5% contrast sensitivity.

Conclusions:Exposure to tertiary amines was associated with blurry, halo, and blue-grey vision, corneal opacity, and decrements in visual acuity and contrast sensitivity at 2.5% contrast.
Social and cultural factors leading to mothers being brought dead to hospital
Authors: Jafarey S.N. , Korejo R.
Published: December 2002

In a 12‐year period (1981–1992) 150 pregnant or recently delivered women were dead when they reached the hospital. Relevant history with emphasis on the events of the previous 24 h and the reasons for delay in reaching the hospital were obtained from the relatives accompanying the patient. The probable cause of death was determined on the basis of history only; no autopsies were done. The causes of delay were economic (54), sociocultural factors (51) and inadequate maternal services (31). In 14 cases the reasons for delay could not be established. The medical problems were either preventable or treatable if managed in time. A combination of economic, social and cultural factors played a more significant role in these deaths than medical causes.
Training of traditional birth attendants: success and failure in Bangladesh
Authors: Nessa S.
Published: December 2002

In Bangladesh, training of traditional birth attendants (TBAs) began in 1978. Since then, the government has prepared over 44000 TBAs. A few thousands more have received instruction through the efforts of various non‐governmental organizations in the country. The objective of TBA training is primarily to change their practices of conducting deliveries. They are taught cleanliness so that maternal and infant mortality, which is significantly high among South and South East Asian nations, may be checked. The writer has herself learned from graduates of the course that they have received sufficient guidance and direction towards performing safe deliveries, a concept totally lacking until that experience. TBAs are thereby in a position to contend with the prevailing socioeconomic and cultural beliefs of the country's rural masses, and to cope with their problems.
Chronic repetitive reaching and grasping results in decreased motor performance and widespread tissue responses in a rat model of MSD
Authors: Barbe Mary F. , Barr Ann E. , Gorzelany Irene , Amin Mamta , Gaughan John P. , Safadi Fayez F.
Published: December 2002

This study investigated changes in motor skills and tissues of the upper extremity (UE) with regard to injury and inflammatory reactions resulting from performance of a voluntary forelimb repetitive reaching and grasping task in rats. Rats reached for food at a rate of 4 reaches/min, 2 h/day, and 3 days/week for up to 8 weeks during which reach rate, task duration and movement strategies were observed. UE tissues were collected bilaterally at weekly time points of 3–8 weeks and examined for morphological changes. Serum was tested for levels of interleukin‐1α (IL‐1) protein. The macrophage‐specific antibody, ED1, was used to identify infiltrating macrophages and the ED2 antibody was used to identify resident macrophages. Rats were unable to maintain baseline reach rate in weeks 5 and 6 of task performance. Alternative patterns of movement emerged. Fraying of tendon fibrils was observed after 6 weeks in the mid‐forelimb. After 4 weeks, a general elevation of ED1‐IR macrophages were seen in all tissues examined bilaterally including the contralateral, uninvolved forelimb and hindlimbs. Significantly more resident macrophages were seen at 6 and 8 weeks in the reach limb. At 8 weeks, serum levels of IL‐1α increased significantly above week 0. Our results demonstrate that performance of repetitive tasks elicits motor decrements, signs of injury and a cellular and tissue responses associated with inflammation.

© 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Differences in the cytokine profiles associated with prostate cancer cell induced osteoblastic and osteolytic lesions in bone
Authors: Lee Y. , Schwarz E. , Davies M. , Jo M. , Gates J. , Wu J. , Zhang X. , Lieberman J. R.
Published: December 2002

Prostate adenocarcinoma is associated with the formation of osteoblastic metastases in bone. It is hypothesized that osteoclastogenesis is a critical component in the development of skeletal metastases. These findings, however, were generally noted in predominantly osteolytic lesions. The pathophysiology of osteoblastic lesions remains unknown but the type of bone lesion formed may be influenced by the cytokines produced by prostate tumors. To test this theory, we implanted PC‐3 and LAPC‐9 cells into the tibias of SCID mice. These mice were sacrificed at 1, 2, 4, 6, and 8 weeks after implantation and histologic analysis was performed on these tibias. PCR analysis was also performed on bulk tumors. The results showed that the PC‐3 implanted tibias developed pure osteolytic lesions while the LAPC‐9 implanted tibias developed pure osteoblastic lesions on radiographs. Analysis of tibias after injection with PC‐3 cells revealed progressive osteolytic lesions with abundant osteoclast activity at 2 weeks and destruction of the proximal tibia at 6 weeks after cell implantation. In contrast, the LAPC‐9 cells formed osteoblastic lesions six weeks after cell injection. There were rare osteoclasts prior to the establishment of the osteoblastic lesions but greater osteoclast activity was noted with remodeling of the osteoblastic lesion 8 weeks after implantation of the tumor cells. PCR analysis revealed that PC‐3 cells produced RANKL, IL‐1, and TNF‐α, which are associated with osteoclastogenesis. In contrast, LAPC‐9 cells produced osteo‐protegerin, which blocks osteoclast production and no detectable levels of RANKL or IL‐1 and only minimal amounts of TNF‐α were noted. These cells secreted BMP‐2, ‐4, ‐6, and IL‐6, which are associated with bone formation. These results suggest that the role of the osteoclast in the development of a metastatic lesion is variable depending on the phenotype of the prostate cancer cells, and that tumor‐induced osteolysis may not be required for osteoblastic metastases.

© 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Inhibition of cell migration from tendon explants into fibrin clots by extracts derived from cheese whey is largely due to transforming growth factor‐beta
Authors: Conlon Michael A. , Tomas Frank M.
Published: December 2002

Whey‐derived growth factor extract (WGFE) and the acid‐activated form (WGFE‐a) were tested for their ability to influence the migration of cells from chicken flexor tendon biopsies into fibrin clots. When added to the medium surrounding clots, both extracts significantly inhibited migration relative to controls (P < 0.05) in a dose‐dependent manner when measurements were made after seven days of incubation. WGFE‐a was approximately ten times more potent than WGFE. Since transforming growth factor (TGF)‐β1 and ‐β2 activity of WGFE‐a is much higher than in WGFE we hypothesized that TGF‐β was responsible for the inhibition of tendon cell migration. Neutralizing anti‐TGF‐β monoclonal antibody was added to the medium bathing tendon biopsies in fibrin clots along with WGFE‐a. WGFE‐a alone inhibited migration by 51% and this was reversed by the antibody in a dose‐dependent manner. Furthermore, recombinant human TGF‐β1 and ‐β2 significantly inhibited tendon cell migration with similar dose‐dependent potency when tested in the assay. These results indicate that TGF‐β is largely responsible for the inhibition of tendon cell migration by WGFE‐a. This sheds further light on the functions of this growth factor during the early events in tendon repair.

© 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Engineered allogeneic mesenchymal stem cells repair femoral segmental defect in rats
Authors: Tsuchida Hiroyuki , Hashimoto Junichi , Crawford Eric , Manske Paul , Lou Jueren
Published: December 2002

Bone marrow derived mesenchymal stem cells (MSC) have been shown to be progenitor cells for mesenchymal tissues. These cells may also provide a potential therapy for bone repair. Our previous studies showed that MSC engineered with the gene for bone morphogenetic protein 2 (BMP‐2), a growth factor for bone cells, were capable of differentiating into osteoblast lineage and inducing autologous bone formation in several animal models. Culturing individual MSC for autologous implantation, however, remains problematic. The number of human MSC with osteogenic potential decreases with age, and, in certain diseases, the patient's marrow may be damaged or the healthy cells reduced in number. In this study, we used rats with a femoral segmental defect to investigate whether allogeneic BMP‐2 engineered MSC would facilitate bone healing. We show that BMP‐2 engineered allogeneic MSC can repair critical bone defects to the same degree as rats treated with BMP‐2 engineered autologous MSC, if the allogeneic group receives short‐term treatment with immunosuppressant FK506. We also show that allogeneic gene transferred MSC are directly involved in bone repair, in addition to acting as gene deliverers.

© 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Artificial Cornea: Towards a Synthetic Onlay for Correction of Refractive Error
Authors: Xie Ruo Zhong , Stretton Serina , Sweeney Deborah F.
Published: December 2002

Synthetic onlays that are implanted onto the surface of the cornea have the potential to become an alternative to spectacles and contact lenses for the correction of refractive error. A successful corneal onlay is dependent on development of a biocompatible polymer material that will maintain a healthy cornea after implantation and that will promote growth of corneal epithelial cells over the onlay, and development of a method for attachment of the onlay with minimal surgical invasiveness. The ideal onlay should be made of a material that is highly permeable yet has sufficient surface characteristics to stimulate stable and firm attachment of the corneal epithelium over the onlay. Recent research indicates that collagen I coated polymer materials that mimic the basement membrane of the corneal epithelium promote the most favorable growth of epithelial cells in vivo in comparison to wholly biological or synthetic materials.
Keratitis
Authors: Sharma Savitri
Published: December 2002

Corneal inflammation or keratitis is a significant cause of ocular morbidity around the world. Fortunately, the majority of the cases are successfully managed with medical therapy, but the failure of therapy does occur, leading to devastating consequences of either losing the vision or the eye. This review attempts to provide current information on most, though not all, aspects of keratitis.

Corneal inflammation may be ulcerative or nonulcerative and may arise because of infectious or noninfectious causes. The nonulcerative corneal inflammation may be confined to the epithelial layer or to the stroma of the cornea or may affect both. For clarity, this section has been divided into nonulcerative superficial keratitis and nonulcerative stromal keratitis. While the former usually includes hypersensitivity responses to microbial toxins and unknown agents, the latter can be either infectious or noninfectious.

In the pathogenesis of ulcerative keratitis, microorganisms such as bacteria, fungi, parasites (Acanthamoeba), or viruses play an important role. Approximately, 12.2% of all corneal transplantations are done for active infectious keratitis. Available world literature pertaining to the incidence of microbial keratitis has been provided special place in this review. On the other hand, noninfectious ulcerative keratitis can be related to a variety of systemic or local causes, predominantly of autoimmune origin.
AN INVESTIGATION OF THE CONTENTS AND CONSEQUENCES OF MAJOR ORGANIZATIONAL INNOVATIONS
Authors: TOTTERDELL PETER , LEACH DESMOND , BIRDI KAMAL , CLEGG CHRIS , WALL TOBY
Published: December 2002

To compare the consequences of different types of major organizational innovation and to identify the characteristics of more beneficial innovations, a telephone interview survey of senior managers from 513 UK organizations was conducted. Although 90% of major innovations were reported to have an overall beneficial impact, statistical analyses showed that specific effects on finances, employee relations, customers, and quality of life depended on the type of innovation and its characteristics. The effects of different types of innovation were related but not reducible to their characteristics. The findings suggest that a more differentiated view of the outcomes of innovation is both possible and useful.
RADIOFREQUENCY RADIATION FROM TRANSMITTER SITES: FACTORS AFFECTING ACCEPTABILITY OF RISK AND PROTECTION STANDARDS
Authors: BEALE IVAN L. , HERIOT SANDRA A. , MURRELL KATHRYN A. , PETRIE KEITH J.
Published: December 2002

Although there is widespread concern about public exposure to radiation from cellphone relay stations, there have been no systematic studies of psychosocial factors affecting public attitudes and beliefs. This paper reports on an analysis of the responses of 105 adults to a questionnaire about their preferences between different standards for exposure to radiation from cellular telephone relay stations and other radiofrequency transmitters. Participants demonstrated clear preference for a more-restrictive (all-effects) protection standard over a less-restrictive (thermal) standard. This preference was not influenced by whether or not participants were personally at risk, or by consideration of costs to industry. Most participants opting initially for an all-effects standard did not shift their preference in the face of substantial hypothetical increases in personal monetary cost. On the other hand, the balance of preference between the two standards was significantly influenced by factors such as the attitude towards the responsibilities of industry, perceptions of possible existing health effects on household members, and self-estimated distance of participants' residences from a transmitter.
Reversible posterior leukoencephalopathy syndrome and silent cerebral infarcts are associated with severe acute chest syndrome in children with sickle cell disease
Authors: Henderson Jessica N. , Noetzel Michael J. , McKinstry Robert C. , White Desiree A. , Armstrong Melissa , DeBaun Michael R.
Published: December 2002

Patients with severe acute chest syndrome (ACS) requiring endotracheal intubation and erythrocytopheresis are at increased risk for neurologic morbidity. This study examines patients with sickle cell disease who developed severe episodes of ACS, leading to endotracheal intubation, ventilatory support for respiratory failure, and erythrocytapheresis. Magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) studies, a neurologic examination by a pediatric neurologist, and cognitive testing were done in all patients. Five consecutive patients, aged 3 to 9 years, were identified with severe ACS. All patients developed neurologic complications resulting from ACS episodes, including seizures (n = 2), silent cerebral infarcts (n = 3), cerebral hemorrhage (n = 2), and reversible posterior leukoencephalopathy syndrome (n = 3). Children with severe ACS should have a magnetic resonance image of the brain, neurologic examination by a neurologist, and cognitive testing to detect the presence of neurologic morbidity.
How effective is antenatal care to promote maternal and neonatal health?
Authors: Acharya S.
Published: December 2002

Antenatal care is effective, but relies heavily on the sympathetic attitude of health personnel. Essential to its promotion is community participation and involvement of family members. Transportation to a well‐equipped facility for emergency obstetric care is a critical element. The effectiveness of antenatal care to reduce maternal morbidity and mortality from certain major causes is reviewed.
Expression of smooth muscle actin in cells involved in distraction osteogenesis in a rat model
Authors: Kinner B. , Pacicca D. M. , Gerstenfeld L. C. , Lee C. A. , Einhorn T. A. , Spector M.
Published: December 2002

Distraction osteogenesis has proven to be of great value for the treatment of a variety of musculoskeletal problems. Little is still known, however, about the phenotypic changes in the cells participating in the bone formation process, induced by the procedure. Recent findings of the expression of a contractile muscle actin isoform, α‐smooth muscle actin (SMA), in musculoskeletal connective tissue cells prompted this immunohistochemical study of the expression of SMA in cells participating in distraction osteogenesis in a rat model. The tissues within and adjacent to the distraction site could be distinguished histologically on the basis of cell morphology, density, and extracellular matrix make‐up. The percentage of SMA‐containing cells within each tissue zone was graded from 0 to 4. The majority of the cells in each of the zones stained positive for SMA within five days of the distraction period. The SMA‐containing cells included those with elongated morphology in the center of the distraction site and the active osteoblasts on the surfaces of the newly forming bone.

These finding warrant further investigation of the role of this contractile actin isoform in distraction osteogenesis and investigation of the effects of modulation of this actin isoform on the procedure.

© 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Evaluation of collagen fiber maturation and ordering in regenerating tendons employing H‐1 double quantum filtered NMR spectroscopy
Authors: Ikoma Kazuya , Kusaka Yoshiaki , Takamiya Hisatake , Eliav Uzi , Navon Gil , Seo Yoshiteru
Published: December 2002

It is difficult to monitor the chronic stage of the healing process of ruptured tendons employing the present diagnostic modes. However, the results of this study have shown that 1H double quantum filtered (DQF) NMR spectroscopy is sensitive to the later stages of the healing process. Regenerated tendons of rabbits were dissected and measured at the end of the acute phase (three weeks), the subacute phase (nine weeks), and the chronic phase (13 and 18 weeks after tenotomy). Four parameters were determined by 1H DQF NMR spectroscopy: (a) the maximum signal intensity (hmax) relative to the single quantum spectrum, (b) the creation time of the maximum signal intensity (τmax), (c) the decay time from the maximum signal intensity to a value half of that intensity (τ1/2) and (d) the residual dipolar splitting of water (δ), representing the order of the collagen fibers. The values of hmax, τmax, τ1/2, and δ of the intact Achilles tendons were 11.3 ± 1.0%, 0.48 ± 0.03 ms, 0.67 ± 0.04 ms and 732 ± 62 Hz (mean ± SEM, n = 6), respectively. In the regenerating tendon, hmax increased from 0.41 ± 0.12% at three weeks to 7.07 ± 0.77% at 18 weeks, τmax decreased from 1.88 ± 0.31 ms at three weeks to 0.72 ± 0.04 ms at 18 weeks, τ1/2 decreased from 11.6 ± 1.8 ms at 3 weeks to 1.48 ± 0.16 ms at 18 weeks, and δ increased from 129 ± 8 Hz at three weeks to 414 ± 29 Hz at 18 weeks. We have concluded that reordering of collagen fibers proceeds continuously even in the chronic stage of healing. Thus, the 1H DQF NMR spectroscopy is a useful non‐invasive technique to evaluate the reconstruction and the order of collagen fibers in regenerating tendon. It is also suggested that τ1/2 and hmax are most useful for in vivo DQF NMR spectroscopy and imaging, respectively, in combination with τmax.

© 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Effects of nicotine on bone mass and strength in aged female rats
Authors: Akhter M. P. , Iwaniec U. T. , Haynatzki G. R. , Fung Y. K. , Cullen D. M. , Recker R. R.
Published: December 2002

This study investigated the effects of nicotine on bone mass and biomechanical properties in aged, estrogen‐replete (sham‐operated) and estrogen‐deplete (ovariectomized) female rats. Eight month old, retired breeder, sham‐operated and ovariectomized Sprague‐Dawley rats were left untreated for 12 weeks to establish cancellous osteopenia in the ovariectomized group. The animals were then administered saline, low dose nicotine (6.0 mg/kg/day) or high dose nicotine (9.0 mg/kg/day) via osmotic minipumps for 12 weeks. Vertebrae and femora were collected at necropsy for determination of bone mass and strength. As expected, ovariectomy had a negative effect on most endpoints evaluated. Vertebral body bone mineral content (BMC) and density (BMD) and the structural (ultimate load and yield load) and material (ultimate stress, yield stress, and flexural modulus of elasticity) strength properties were lower in the OVX rats than in the sham‐operated rats. Femoral diaphysis BMC, BMD, ultimate load, and flexural modulus were also lower in the OVX rats than in the sham‐operated rats. The nicotine doses administered resulted in serum nicotine levels that averaged 1.5–4.5‐fold greater than those observed in heavy smokers. Despite the high doses used, nicotine had no effect on vertebral BMC, BMD, or any of the structural and material strength properties in either the OVX or the Sham rats. In addition, nicotine had no effect on femoral diaphysis BMC, BMD, ultimate load, stiffness, ultimate stress, or flexural modulus. Femoral yield load and stress were lower in low dose nicotine‐treated rats than in vehicle‐treated rats. However, differences were not detected between the high dose nicotine‐ and vehicle‐treated rats for either femoral yield load or stress. The results suggest that tobacco agents other than nicotine are responsible for the decreased bone density and increased fracture risk as observed in smokers.

© 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Contact Lens Related Corneal Infections
Authors: Willcox M.D.P. , Holden B.A.
Published: December 2002

This article describes microbial keratitis, infection of the cornea by micro-organisms. Contact lens wear is a predisposing factor for the development of microbial keratitis. Micro-organisms probably adhere to the contact lens, transfer from the contact lens to a damaged or compromised corneal epithelial surface, penetrate into the deeper layers of the cornea and produce corneal damage. Host responses to the invading micro-organisms, while designed to protect the eye, can often exacerbate the situation and the resulting microbial keratitis can lead to permanent blindness. The microbial, biochemical and immunological aspects of MK will be described in detail.
Treating Depression in Primary Care: An Innovative Role for Mental Health Nurses
Authors: Saur Carol D. , Harpole Linda H. , Steffens David C. , Fulcher Caryl D. , Porterfield Yvonne , Haverkamp Rita , Kivett Dena , Unützer Jürgen
Published: December 2002

Late-life depression is common in primary care. However, because of barriers such as stigma and the assumption that depression in older adults is a normal part of aging, it is often under recognized and under treated. Further, most primary care providers do not have the time or resources to provide adequate follow-up depression care. By integrating a depression clinical specialist into the primary care setting, many of these barriers to effective treatment can be addressed. In this paper, a collaborative, stepped care treatment program with registered nurses practicing as depression clinical specialists is described. Additionally, three case reports illustrate the model. This intervention program offers a unique opportunity for mental health nurses to practice collaboratively in the primary care setting and to provide much needed care to an underserved population.
Assessment and Diagnosis of Sexual Addiction
Authors: Coleman-Kennedy Carol , Pendley Amanda
Published: December 2002

As many as 20 million people in the United States are affected by sexual addiction. However, few clinicians assess for its existence, and most nursing program curricula are not addressing this phenomenon. Sexual addiction often coexists with substance addiction, and both can be destructive to persons and families. Clinicians who recognize the risk factors for possible sexual addiction, often revealed in the initial psychiatric assessment, can further assess for its existence in patients. The authors present an algorithm to enhance clinicians’ abilities to recognize, assess, and diagnose sexual addiction during a substance addiction assessment.
The role of emergency obstetric care in preventing maternal deaths: an historical perspective on European figures since 1751
Authors: Papiernik E.
Published: December 2002

A review of the time‐relationships is provided between the introduction of obstetric techniques and organization of obstetric care in Europe and the decrease of maternal death rates from 1751 to 1980. Published figures were used to discover the evolution of maternal deaths in Europe for the last 250 years, and to propose a parallel analysis of major modifications of obstetric care. The teaching of obstetrics to midwives and general practitioners, introduction of forceps and of low‐segment cesarean section technique, disappearance of home deliveries, antibiotics, anesthesia and blood banks are among the addressed techniques. Even if a causal relationship cannot be proposed, the major inflection in the rate of reduction of maternal deaths is related to the introduction of low segment cesarean section in the first years of the 20th century. This progress was also related to the progressive transfer of birth sites, from home to specialized units.
Traditional birth attendants in Bangladeshi villages: cultural and sociologic factors
Authors: Rozario S.
Published: December 2002

World Health Organization policy for some years has emphasized working through traditional birth attendants as the best path to improving the appalling level of maternal and child mortality and illness in much of the Third World. The universal appropriateness of this strategy has begun to be called into question. Recent research on childbirth in rural Bangladesh, as elsewhere in South Asia, suggests that the concept of the ‘traditional birth attendant’ in the context of this region needs to be reexamined. The dai typically have tittle training and low status, due to their close association with the removal of birth pollution. A policy based on converting them into modern health professionals faces serious obstacles. In practice, neither the poorly‐trained village dai nor such biomedically‐trained practitioners as are available at the village level are able to deliver competent health care. Their effectiveness is further compromised by the cultural and material environment within which they operate. A more adequate approach to care for birthing women in the village still has to be developed.
Protective effects of intermittent hydrostatic pressure on osteoarthritic chondrocytes activated by bacterial endotoxin in vitro
Authors: Lee Mel S. , Ikenoue Takashi , Trindade Michael C. D. , Wong Neal , Goodman Stuart B. , Schurman David J. , Smith R. Lane
Published: December 2002

The role of continuous passive motion (CPM) in the management of septic arthritis and inflammatory arthritis remains of interest. CPM produces cyclic variations in intraarticular pressure that facilitates transport of fluid, nutrients, and solutes within and/or across the joint and stimulates chondrocyte metabolism. However, the precise mechanisms mediating the responses of chondrocytes to joint motion remain unclear. This study tested the hypothesis that dynamic mechanical loading counteracts effects of bacterial lipopolysaccharide (LPS), an inflammatory mediator, on chondrocyte metabolism. Intermittent hydrostatic pressure (IHP) (10 MPa for 4 h) was applied to human chondrocytes pretreated with LPS (1 μg/ml for 18 h). LPS activation of chondrocytes decreased mRNA signal levels of type II collagen by 67% and aggrecan by 56% and increased nitric oxide by 3.1‐fold, monocyte chemotactic protein‐1 mRNA signal levels by 6.5‐fold, and matrix metalloproteinase‐2 mRNA signal levels by 1.3‐fold. Application of IHP to LPS‐activated chondrocytes decreased nitric oxide synthase mRNA signal levels and nitric oxide levels in the culture medium. Exposure of LPS‐activated chondrocytes to IHP upregulated type II collagen and aggrecan mRNA signal levels by 1.7‐fold, relative to chondrocytes activated by LPS and maintained without loading. In addition, application of IHP decreased the upregulation in signal levels of monocyte chemotactic factor‐1 and matrix metalloproteinase‐2 following LPS activation by 45% and 15%, respectively. These data show that mechanical loading counteract effects of inflammatory agents, such as bacterial LPS, and suggest that postinfection sequelae are influenced by the presence or absence of joint loading.

© 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
The fate of soft callus chondrocytes during long bone fracture repair
Authors: Ford Joanna L. , Robinson Derek E. , Scammell Brigitte E.
Published: December 2002

Following fracture, the cartilaginous tissue of the soft callus is eventually replaced by bone. Removal of the cartilage is a critical part of the bone healing process but information concerning the changes in chondrocytes during this process is sparse. The aim of the study was to investigate the fate of chondrocytes in the soft callus during the bone repair process using a rabbit tibial fracture model. Fracture tissue was processed for collagen I‐III and keratan sulphate immunohistochemistry to study changes in matrix composition and the TUNEL technique (terminal deoxynucleotidyl transferase medicated dUTP nick‐end labelling) to identify death of soft callus chondrocytes. Transmission electron microscopy (TEM) was also carried out to investigate the ultrastructure of chondrocytes within the soft callus. Results showed that the size of the cartilage area decreased over time and that cartilage matrix was replaced with new matrix rich in collagen I and III. Chondrocytes became engulfed in the new matrix and appeared to stop producing cartilage matrix. Chondrocyte cell death was seen at the border of the soft callus, just within the newly produced matrix. TEM revealed that these dying/dead cells were not typically apoptotic in appearance. In conclusion, results indicate that chondrocytes of the soft callus die as a result of the progressive production of bone matrix which eventually engulfs them and leads to the remodelling of the area and eventual bone repair.

© 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Epigallocatechin‐3‐gallate selectively inhibits interleukin‐1 β‐induced activation of mitogen activated protein kinase subgroup c‐Jun N‐terminal kinase in human osteoarthritis chondrocytes
Authors: Singh Rashmi , Ahmed Salahuddin , Malemud Charles J. , Goldberg Victor M. , Haqqi Tariq M.
Published: December 2002

Activation of mitogen activated protein kinases (MAPK) is a critical event in pro‐inflammatory cytokine‐induced signaling cascade in synoviocytes and chondrocytes that lead to the production of several mediators of cartilage damage in an arthritic joint. Green tea (Camellia sinensis) is a widely consumed beverage and we earlier showed that polyphenols present in green tea (GTP) inhibit the development of inflammation and cartilage damage in an animal model of arthritis. In this study we evaluated the role of epigallocatechin‐3‐gallate (EGCG), a green tea polyphenol which mimics its anti‐inflammtory effects, in modulating the IL‐1β‐induced activation of MAPK's in human chondrocytes. We discovered that EGCG inhibited the IL‐1β‐induced phosphorylation of c‐Jun N‐terminal kinase (JNK) isoforms, accumulation of phospho‐c‐Jun and DNA binding activity of AP‐1 in osteoarthritis (OA) chondrocytes. Also IL‐1β, but not EGCG, induced the expression of JNK p46 without modulating the expression of JNK p54 in OA chondrocytes. In immunecomplex kinase assays, EGCG completely blocked the substrate phosphorylating activity of JNK but not of p38‐MAPK. EGCG had no inhibitory effect on the activation of extracellular signal‐regulated kinase p44/p42 (ERKp44/p42) or p38‐MAPK in OA chondrocytes. EGCG or IL‐1β did not alter the total non‐phosphorylated levels of either p38‐MAPK or ERKp44/p42 in OA chondrocytes. These are novel findings and indicate that EGCG may be of potential benefit in inhibiting IL‐1β‐induced catabolic effects in OA chondrocytes that are dependent on JNK activity.

© 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.