Kinematic posture analysis of orthodontists in their daily working practice.

PURPOSE: The aim of this study is to conduct a kinematic analysis of occupational posture in orthodontists. METHODS: A representative sample of 21 (13 female/8 male) residents in orthodontics and orthodontists was studied. The CUELA system collects kinematic data of the occupational posture. Alongside the kinematic analysis, the tasks performed on-site were also subject to a detailed computerized analysis. Data analysis comprised the evaluation and comparison of joint angle distribution in accordance with ergonomic standards categorized as neutral, moderate or awkward posture. RESULTS: The most common activities were executed in a seated position. During "treatment" (28% of total time) participants most often worked with a straight back (84.7%), whereas a "bent or twisted" torso posture was observed 23.4% of the time. For head and cervical spine, the 75th and 95th percentiles presented worse (higher) values during treatment as compared to non-orthodontic activities. The seated position next to the patient during treatment showed a stronger inclination of the thoracic spine to the right and an inclination of the lumber spine to the left. CONCLUSIONS: Orthodontists do take characteristic postures during treatment activities with highest angle values. The postures differ in the area of head and cervical spine with regard to the various activities carried out in the 3 categories.

Motion analysis in the field of dentistry: a kinematic comparison of dentists and orthodontists.

OBJECTIVES: To conduct a kinematic comparison of occupational posture in orthodontists and dentists in their workplace. DESIGN: Observational study. SETTING: Dentist surgeries and departments of orthodontics at university medical centres in Germany. PARTICIPANTS: A representative sample of 21 (10 female, 11 male) dentists (group G1) and 21 (13 female, 8 male) orthodontists (G2) with one male dropout in G2. OUTCOME MEASURES: The CUELA (computer-assisted acquisition and long-term analysis of musculoskeletal loads) system was used to analyse occupational posture. Parallel to the recording through the CUELA system, a software-supported analysis of the activities performed (I: treatment; II: office; III: other activities) was carried out. In line with ergonomic standards the measured body angles are categorised into neutral, moderate and awkward postures. Activities between the aforementioned groups are compared using the stratified van Elteren U test and the Wilcoxon-Mann-Whitney U test. All p values are subject to the Bonferroni-Holm correction. The level of significance is set at 5%. RESULTS: The percentage of time spent on activities in categories I-II-III was as follows: dentists 41%-23%-36% and orthodontists 28%-37%-35%. The posture analysis of both groups showed, for all percentiles (P5-95), angle values primarily in the neutral or moderate range. However, depending on the activity performed, between 5% and 25% of working hours were spent in unfavourable postures, especially in the head-and-neck area. Orthodontists have a greater tendency than dentists to perform treatment activities with the head and torso in unfavourable positions. The statistically significant differences between the two groups with regard to the duration and the relevance of the activities performed confirm this assumption for all three categories (p<0.01, p<0.05). CONCLUSIONS: Generally, both groups perform treatment activities in postures that are in the neutral or medium range; however, dentists had slightly more unfavourable postures during treatment for a greater share of their work day.

PO-58 - Cardiovascular risk profile in survivors of adult cancer - results from the general population study.

INTRODUCTION: The advancements in cancer treatment and detection of early cancer have resulted in steady increase of adult cancer survivors over the years. However, due to the long term toxic effects of chemotherapy and radiotherapy, the incidence of cardiovascular diseases (CVD) is increasing in survivors. Identifying risk factors and interventions to reduce the excess burden of CVD in this vulnerable population is urgently needed. AIM: To investigate the cardiovascular risk factors (CVRFs), inflammation and coagulation profile in cancer survivors from a large population-based study. MATERIALS AND METHODS: Presence of CVRFs and laboratory markers have been compared in individuals with (n=1,359) and without (n=13,626) history of cancer. Standard laboratory profile, including blood glucose and lipid profile, has been evaluated in 15,010 individuals from the Gutenberg Health Study (GHS). Coagulation factors, D-dimer and von Willebrand factor (vWF) activity were available in N=4,993. RESULTS: The individuals with history of cancer were older compared to no history of cancer with mean age of 61,5years and 54.4years, respectively (p<0.001). Traditional CVRFs as diabetes (14% vs 8.8%), dyslipidemia (49.6% vs 43.7%) and hypertension (60.3 vs 48.7%) were more frequent whereas smoking was less frequent (14.5% vs 19.9%) in cancer survivors (p<0.001). The standard laboratory profile showed cancer survivors with lower erythrocyte, platelet and white blood cell counts and higher C-reactive protein (CRP), glucose, HbA1c and triglycerides levels (p<0.001). Multivariable logistic regression analysis adjusted for age, sex and CVRFs demonstrated an independent association with diabetes (odds ratio, OR: 1.24, 1.02-1.50; p=0.027) and higher CRP (OR: 1.01, 1.01-1.02; p=0.00071). Fibrinogen, FV, FVII, FVIII and FXI, D-dimer and vWF activity were higher in cancer survivors (p<0.001). Multivariable logistic regression confirmed an independent association with higher fibrinogen (OR: 1.002, 1.000-1.003) and vWF activity (OR: 1.005, 1.001-1.008). CONCLUSIONS: This is the first study investigating CVRFs, inflammation and coagulation profile in individuals with history of cancer from a well characterized population-representative adult sample. It gives evidence for higher prevalence of CVRFs, particularly diabetes in this vulnerable population. Markers of inflammation as CRP and fibrinogen and vWF activity were higher in cancer survivors independent of the cardiovascular risk profile. These results underline the increased risk of CVD and need for development of cardio-oncology programs offering cardiovascular prevention.

Improving ergonomics in milking parlors: empirical findings for optimal working heights in five milking parlor types.

Milking postures have shifted from seated milking in tethered stalls to milking in a standing position in parlors. However, the musculoskeletal workload of dairy farmers remains high. Previous studies have shown that different working heights affect ergonomics, but they could not objectively evaluate and quantify the workload. The aim of the present study was to assess the effect of working height in different milking parlor types on the milker's workload during the task of attaching milking clusters. Computer-assisted recording and long-term analysis of movements were used to record positions of joints and body regions while performing certain tasks in terms of angular degrees of joints (ADJ) according to the neutral zero method. The 5th, 50th, and 95th percentiles described the distribution of angular degree values measured for each joint. The ADJ were evaluated according to international standards and other scientific literature on the issue to assess the muscular load. The workload was compared between 5 parlor types (auto tandem, herringbone 30°, herringbone 50°, parallel, and rotary) on 15 farms with 2 subjects per parlor and 1 milking period per subject. The working height was defined as a coefficient based on the milker's body height, the floor level, and the cow's udder height. The data recorded during the attachment task were analyzed using generalized linear mixed-effects models taking into account the hierarchical experimental design. The results indicated that the interaction of the cow's udder height, the milker's body height, and the parlor type had a larger effect on ergonomics than each parameter had independently. The interaction was significant in at least 1 of the 3 percentiles in 28 out of 31 ADJ. The postural differences between parlor types, however, were minor. A milking health formula was created to calculate the ideal depth of pit by considering the parlor type, the milker's height, and the mean herd udder height. This formula can be used to develop individual recommendations for future parlor construction.

[Locoregional deformation pattern of the patellar cartilage after different loading types - high-resolution 3D-MRI volumetry at 3 T in-vivo]. / Lokoregionäre Deformationsmuster im Patellarknorpel nach unterschiedlichen Belastungsparadigmen - hochauflösende 3-D-MR-Volumetrie bei 3 T in vivo.

PURPOSE: To analyze locoregional deformation patterns indicative of contact areas in patellar cartilage after different loading exercises. MATERIALS AND METHODS: 7 healthy patellae were examined in-vivo before and immediately after standardized loading (kneeling, squatting or knee bends) and after 90 minutes of rest using a sagittal 3D-T1-w FLASH WE sequence (22 msec/ 9.8 msec/ 15°/ 0.3 × 0.3 × 1.5 mm³) at 3 T. After cartilage segmentation and 3D reconstruction, voxel-based and global precision errors (PR) were calculated. The former were used to determine significant differences in local cartilage thickness. Voxel-based 2σ-thickness difference maps were calculated to visualize locoregional deformation patterns. Global changes in volume (Vol), mean thickness (mTh) and cartilage-bone-interface area (CBIA) were calculated. RESULTS: The voxel-based PR depended on cartilage thickness (D) ranging from 0.12 - 0.35 mm. For D ≥ 1 mm the RF was < 0.31 mm (< voxel size), and for D ≥ 2 mm, the RF was < 0.22 mm. The global PR was 83 mm³ (2.4 %) for Vol, 0.06 mm (2.0 %) for mTh and 16 mm² (1.4 %) for CBIA. The focal cartilage deformation equaled 14 % of the local thickness reduction. The deformation areas were oval and located in the peripheral medial (more vertically oriented, all exercises) and caudo-lateral (more horizontally oriented, kneeling and knee bends) aspects of the patella and were least pronounced in knee bends. Significant changes for Vol/mTh ranged from 2.1 to 3.7 %. CONCLUSION: This MRI-based study is the first to identify in-vivo voxel-based patellar cartilage deformation patterns indicating contact and loading zones after kneeling and squatting. These zones are anatomically and functionally plausible and may represent areas where stress induced degeneration and subsequent OA can originate. The data may facilitate understanding of individual knee loading properties and help to improve and validate biomechanical models for the knee.

Induction of stress proteins in human endothelial cells by heavy metal ions and heat shock.

In the present study, we compared the induction of heat shock proteins (HSPs) by heat and heavy metal ions in three different endothelial cell types, namely, human umbilical vein endothelial cells, human pulmonary microvascular endothelial cells, and the cell line EA.hy 926. Our results show that especially Zn(2+) and Cd(2+) are inducers of 70-kDa (HSP70), 60-kDa (HSP60), 32-kDa (HSP32), and 27-kDa (HSP27) HSPs. The strength of inducibility is specific for each HSP. Ni(2+) and Co(2+) only show an inducible effect at very high concentrations, that is, in the clearly cytotoxic range. Furthermore, we investigated the time course of HSP expression and the involvement of heat shock factor-1. Our study demonstrates that the three endothelial cell types that were under investigation show comparable stress protein expression when treated with heavy metal ions or heat shock. The expression of stress proteins may be used as an early marker for the toxic damage of cells. This damage can be an inducer of acute respiratory distress syndrome in which microvascular endothelial lesions occur early. Our study provides evidence that human umbilical vein endothelial cells or EA.hy 926 cells, which are much more easily isolated and/or cultivated than pulmonary microvascular endothelial cells, could be used as alternative cell culture systems for studies on cellular dysfunction in the lung caused by toxic substances, certainly with respect to the expression of HSPs.

Physiology and cell biology of the endothelium: a dynamic interface for cell communication.

This manuscript presents a brief overview of the physiology and cell biology of the endothelium, which is the basis for understanding the role of endothelial cells in pathological processes as diverse as atherosclerosis, tumour intravasation and multiple organ failure. Following consideration of general aspects of endothelial function in regulating haemostasis, vascular tone and growth, special emphasis will be placed on endothelial regulation of the inflammatory response, which centres on the microcirculation. A particular role in inflammation is played by cell adhesion molecules (CAM), expressed both on endothelial and blood cells. Cell and molecular biological methods to investigate the expression of CAM in endothelial cells in vitro will be presented, as well as novel data, indicating that cytokine-induced up-regulation of CAM in the endothelium may involve signal transduction pathways other than those culminating in the activation of NF-kappa B. Finally, the phenomenon of angiogenesis will be briefly reviewed as a characteristic of endothelial cell activity of central importance to both physiology and pathology and new experimental data presented from an in vitro model to study the ability of individual endothelial cells to form vessel-like structures. In comparative studies to investigate the roles of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor, the dominant role of VEGF in the formation of capillary networks could be unequivocally demonstrated.

Comparative studies on vascular endothelium in vitro. 2. Hypoxia: its influences on endothelial cell proliferation and expression of cell adhesion molecules.

Recent studies have presented evidence that the processes of hypoxaemia and reperfusion are involved in several pathogenetic mechanisms of atherosclerotic lesions. The ability of hypoxaemia to activate circulating white blood cells (WBCs) and enhance WBC-endothelial cell (EC) interactions is suspected to be a major factor in deleterious processes in the blood vessel wall. Various groups have suggested that cell adhesion molecules (CAMs), such as ICAM-1, VCAM-1 and E-selectin and their leukocyte ligands are involved in intercellular activities of the relevant cell types. We studied the effects of different oxygen tensions, simulating normoxic conditions, hypoxia and hyperoxia in vitro with the help of an umbilical vein EC model in order to determine the effects of oxygenation on CAM presentation on vascular ECs with and without further cytokine and endotoxin (lipopolysaccharides; LPS) stimulation. Semiquantitative analysis of ICAM-1, E-selectin and VCAM-1 was performed using cell enzyme immunoassay techniques. The presentation of ICAM-1, E-selectin and VCAM-1 remained on the whole unaffected by both hypoxia and hyperoxic conditioning after both 7 and 24 h. Stimulation of ICAM-1 by cytokines and LPS was only marginally influenced by the oxygen tension. Cytokine induction of E-selectin was not affected after 7 h and was even reduced under hypoxia, compared to the control culture after 24 h, while stimulation was increased by hyperoxia. VCAM-1 was reduced in both the hypoxic and hyperoxic culture, while being maximally stimulated by cytokines and LPS after 7 h. In general, an effect of hypoxia was not found without any further stimulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparative studies on vascular endothelium in vitro. 3. Effects of cytokines on the expression of E-selectin, ICAM-1 and VCAM-1 by cultured human endothelial cells obtained from different passages.

Endothelial cells (EC) are very responsive to proinflammatory cytokines, e.g. interleukin-1 (IL-1) and tumor necrosis factor alpha (TNF alpha), as well as to bacterial lipopolysaccharide. EC are stimulated by these substances to secrete chemotactic factors and to increase expression of cell adhesion molecules (CAM), leading to dramatically altered interactions with leukocytes, e.g. granulocytes and monocytes. In these interactions E-selectin, ICAM-1 and VCAM-1 are known to play an important role, as they are presented by the EC and interact with corresponding ligands on the white blood cell membranes. These adhesion molecules have been studied worldwide in a variety of in vitro experiments using cultured EC. Different passages and mixtures of passages have been used in these experiments, often without any regard to the comparability of the results. In this study the expression of E-selectin, ICAM-1 and VCAM-1 on cultured human umbilical vein EC (HUVEC) obtained from different passages (passages 1-6) was studied after 4, 8 and 24 h of exposure to IL-1 beta and TNF alpha. In previous studies, we have shown that IL-1 beta and TNF alpha increase the expression of E-selectin and ICAM-1 on the cytoplasmatic membranes of HUVEC and human adult EC from the saphenous vein and femoral artery in a similar fashion. Using a comparative quantitative cell enzyme immunoassay, we found that the expression of the adhesion molecules was significantly reduced with increasing passages. There was also a decreased persistence of CAM comparing different periods of stimulation between 6 and 24 h in the different passages. These data indicate that the number of passages plays an important role in the expression of adhesion molecules on EC. The results are relevant for the meaningful planning of comparative in vitro studies on EC presentation of CAM.

Comparative studies on vascular endothelium in vitro. I. Cytokine effects on the expression of adhesion molecules by human umbilical vein, saphenous vein and femoral artery endothelial cells.

Endothelial cells (ECs) are very responsive to proinflammatory cytokines. ECs are stimulated by these substances to increase expression of cell surface adhesion molecules, leading to dramatically altered interactions with leukocytes. In these interactions, E-selectin, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) are suggested to play the most important role. Recent evidence has suggested diversity in the responses of ECs from different regions of the vascular system. Human umbilical vein ECs (HUVECs) are the most often used EC culture model, although there are few studies comparing their response with other human EC types from the adult organism. In this study the expression of E-selectin, ICAM-1 and VCAM-1 on cultured human adult ECs from the saphenous vein (HSVECs) and from the femoral artery (HAFECs), as well as HUVECs was studied. Using a cell enzyme immunoassay as well as immunoelectron microscopical methods, we found that both HSVECs and HAFECs respond in a similar way to HUVECs to exogenous stimulation by IL-1 beta, TNF alpha or LPS. IL-1 beta and TNF alpha increased the expression of E-selectin on the cytoplasmic membranes of HUVECs, HSVECs and HAFECs and elicited even similar absolute quantities of this molecule, comparing the different cell types. ICAM-1 and VCAM-1 appeared to be regulated dose dependently by IL-1 beta, independent of the EC type. HUVECs as well as HSVECs and HAFECs gave a reproducible constitutive ICAM-1 expression, whereas E-selectin and VCAM-1 were absent on nonstimulated ECs.(ABSTRACT TRUNCATED AT 250 WORDS)