AB1570-PARE PROFILING LOW BACK PAIN PATIENTS FOR THE DEVELOPMENT OF A PERSONALIZED COACHING APPLICATION

Background

Low back pain is a major public health problem that is increasing with the aging of the population. It is the leading cause of disability in most countries [1]. The recommendations of Inserm (2019) include personalized physical activity programs according to the individual characteristics (motivation, preferences, attitude towards physical activity) and life context of each patient (family and professional load, socioeconomic level, living place) [2]. However, the current management of chronic low back pain includes rehabilitation programs that are costly and/or not always personalized, which reduces their effectiveness.

Objectives

The objective of this research is to better understand the characteristics of people with chronic low back pain to identify main motivational profiles that will allow us to offer personalized coaching via a mobile application.

Methods

After a review of the literature and following advice from experts in the management of chronic low back pain, we selected 8 scales to characterize patients: General Health Status (MYMOP), Treatment Burden (TBQ), Quality of Life (EQ-5D-5L), Level (IPAQ), Fears and Beliefs (FABQ-AP), and Motivation (EMAPS) for physical activity, Emotional Status (PHQ-9), and Sense of Self-Efficacy (FC-CPSES). These questionnaires were administered online to participants in the ComPaRe (Community of Patients for Research) chronic low back pain cohort. An initial descriptive analysis of the results allowed us to describe our sample. In order to distinguish different motivational profiles of patients towards physical activity, we performed a Agglomerative Hierarchical Clustering (AHC) and a principal component analysis (PCA) of the results of the EMAPS, PHQ-9, FABQ-AP and FC-CPSES scales.

Results

A total of 193 patients with chronic low back pain were included (m ≃ 54years, s ≃ 13years; majority women (74%); duration of low back pain: m ≃ 15years, s ≃ 12years; occupational status: 44% employed, 22% on disability, 19% retired). Clustering analysis allowed us to distinguish 4 main profiles that we named as follows: (1) “Amotivated,” characterized by the lowest motivation and highest amotivation toward physical activity (i.e. they do not understand why it is useful), (2) “Cautious” with low motivation and having the highest fears and beliefs toward physical activity, (3) “Depressed” with good intrinsic motivation but also a significant level of depressive symptoms, and (4) “Confident” also showing good intrinsic motivation and having the highest sense of self-efficacy.

Conclusion

The main novelty of this research is a new classification of 4 motivational profiles in the low back pain population determined by a clustering method. This typology is in line with the HAPA model of behavior change [3]. It will allow us to make recommendations for the design of a personalized mobile coaching application. Future work will aim to test and evaluate the personalization of e-coaching according to these profiles.

References

[1]Hurwitz, E.L., Randhawa, K., Yu, H. et al. Initiative mondiale de soins de la colonne vertébrale: un résumé du fardeau mondial des études sur les douleurs lombaires et cervicales. Eur Spine J 27, 796–801 (2018). https://doi.org/10.1007/s00586-017-5432-9

[2]Julie Boiche, Béatrice Fervers, Damien Freyssenet, Isabelle Gremy, Thibaut Guiraud, et al. Activité physique: Prévention et traitement des maladies chroniques. [Rapport de recherche] Institut national de la santé et de la recherche médicale(INSERM). 2019, Paris: Inserm: Éditions EDP Sciences (ISSN: 0990-7440) / 824 p.〈inserm-02102457〉

[3]Schwarzer, R. (2016). Health action process approach (HAPA) as a theoretical framework to understand behavior change. Actualidades en Psicología, 30(121), 119–130. https://doi.org/10.15517/ap.v30i121.23458

Disclosure of Interests

None declared

Factor VII-Deficient Substrate Plasmas Depleted of Protein C Raise the Sensitivity of the Factor VII Bio-Assay to Activated Factor VII: an International Study

Plasma from healthy individuals, pregnant women and patients on warfarin were distributed to 3 laboratories supporting major cardiovascular surveys (Northwick Park, Muenster and Houston) for assay of factor VII coagulant activity (VIIC) with their own bio-assays. The mean VIIC in 147 samples agreed to within 1% of standard in Northwick Park and Houston, but was 14% of standard lower in Muenster owing to its more potent standard. In samples with an increased VIIC the Northwick Park assay gave a higher result than the other assays owing to its increased responsiveness to activated factor VII (VIIa). Thus when VIIa concentrations were determined directly with a clotting assay which utilises a soluble recombinant tissue factor, the increase in VIIC with increase in VIIa was considerably greater with the Northwick Park assay than the Muenster assay. This feature of the Northwick Park assay was traced to the virtual absence of protein C in its substrate plasma. Factor Va appears rate-limiting for the coagulant expression of VIIa in test plasma. If the thrombotic response to release of tissue factor is determined by the circulating concentration of VIIa, then the Northwick Park factor VII bio-assay may be preferable to other bio-assays currently employed to estimate risk of acute coronary events.

Sources of Variability in Coagulation Factor Assays

Estimates of the components of variation of a number of coagulation factor assays are presented and are compared with those for other haematological and biochemical variables. They have been derived from a study in which fourteen volunteers gave blood samples approximately bi-monthly for three years. The systematic between-batch variation w7as generally only a small component of the total variation. However, the proportion of the total variation due to differences between people ranged from about 15% in the case of two measures of antithrombin III to about 85% for cholesterol and haemoglobin. For factor VII activity and fibrinogen, the figure was just over 70%. These estimates of the components of variation are not generally available in the literature. In view of the increasing interest in the role of coagulation factors in the pathogenesis of arterial disease, estimates of this kind are needed both for the interpretation of observed relationships as well as for planning sample sizes for future studies.

Very Low Activated Factor VII and Reduced Factor VII Antigen in Familial Abetalipoproteinaemia

Abetalipoproteinaemia is a rare disorder of apolipoprotein B metabolism associated with extremely low plasma concentrations of triglyce-ride. To discover whether the general positive association between factor VII and triglyceride levels extends to this condition, 5 patients were compared with 18 controls. All patients had a triglyceride below 100 μmol/l. Plasma unesterified fatty acid concentration was normal. Although factor IX activity was only slightly reduced (mean 88% standard) and factor IX antigen was normal, mean activated factor VII in patients was strikingly reduced to 34% of that in controls, a level similar to that found in haemophilia B. The patients’ mean factor VII activity and factor VII antigen were also significantly reduced to 54% and 63% of those in controls, respectively. Mean factor XI activity and tissue factor pathway inhibitor activity were reduced in patients to 70% and 75% of control values respectively, while factor XII, factor XI antigen, factor X, prothrombin and protein C were normal.

Development of a Web Site for Transplant Patient Education

The Internet is a global communication network used by more than 17.6 million adults as a major source of current health information. Both the number of health-related Web sites and the number of Web users are increasing exponentially as well as reports indicating a growth in the number of persons who access the Internet specifically to retrieve information about organ transplantation. However, few are using this medium for posttransplant educational or psychosocial purposes. Armed with this information, as well as a commitment from the transplant team, we chose to develop a Web-based educational program to facilitate posttransplant care for our transplant recipients. The purpose of this article is to describe the planning, development, and implementation of a Web-based education program for transplant recipients.

Exenatide decreases liver fat content and epicardial adipose tissue in patients with obesity and type 2 diabetes: a prospective randomized clinical trial using magnetic resonance imaging and spectroscopy

AIM

To conduct a prospective randomized trial to investigate the effect of glucagon-like peptide-1 (GLP-1) analogues on ectopic fat stores.

METHODS

A total of 44 obese subjects with type 2 diabetes uncontrolled on oral antidiabetic drugs were randomly assigned to receive exenatide or reference treatment according to French guidelines. Epicardial adipose tissue (EAT), myocardial triglyceride content (MTGC), hepatic triglyceride content (HTGC) and pancreatic triglyceride content (PTGC) were assessed 45 min after a standardized meal with 3T magnetic resonance imaging and proton magnetic resonance spectroscopy before and after 26 weeks of treatment.

RESULTS

The study population had a mean glycated haemoglobin (HbA1c) level of 7.5 ± 0.2% and a mean body mass index of 36.1 ± 1.1 kg/m(2) . Ninety five percent had hepatic steatosis at baseline (HTGC ≥ 5.6%). Exenatide and reference treatment led to a similar improvement in HbA1c (-0.7 ± 0.3% vs. -0.7 ± 0.4%; p = 0.29), whereas significant weight loss was observed only in the exenatide group (-5.5 ± 1.2 kg vs. -0.2 ± 0.8 kg; p = 0.001 for the difference between groups). Exenatide induced a significant reduction in EAT (-8.8 ± 2.1%) and HTGC (-23.8 ± 9.5%), compared with the reference treatment (EAT: -1.2 ± 1.6%, p = 0.003; HTGC: +12.5 ± 9.6%, p = 0.007). No significant difference was observed in other ectopic fat stores, PTGC or MTGC. In the group treated with exenatide, reductions in liver fat and EAT were not associated with homeostatic model assessment of insulin resistance index, adiponectin, HbA1c or fructosamin change, but were significantly related to weight loss (r = 0.47, p = 0.03, and r = 0.50, p = 0.018, respectively).

CONCLUSION

Our data indicate that exenatide is an effective treatment to reduce liver fat content and epicardial fat in obese patients with type 2 diabetes, and these effects are mainly weight loss dependent.

Cidofovir, a New Agent with Potent Anti-Herpesvirus Activity

Cidofovir is a potent, broad spectrum antiviral agent with activity in vitro and in vivo against cytomegalovirus and other members of the herpesvirus family, as well as certain other DNA viruses. After uptake into cells it is converted enzymatically to cidofovir diphosphate, a structural analogue of deoxycytidine triphosphate, which selectively inhibits viral DNA polymerases relative to host cell polymerases. Cross-resistance to cidofovir is not usually seen with human cytomegalovirus isolates that are foscarnet-resistant, or isolates that are ganciclovir-resistant due to a deficiency in ganciclovir phosphorylation. Cross-resistance is seen, however, with isolates that are ganciclovir resistant due to polymerase mutations. A prolonged elimination phase seen in vivo, correlates with a long intracellular half-life seen in vitro and allows for efficacy in animal models of virus infection with infrequent dosing or prophylaxis. Clinical studies of intravenous cidofovir in cytomegalovirus retinitis in patients with AIDS are claimed to show delay of retinitis progression with maintenance doses given once every 2 weeks.

Intestinal microbiota contributes to individual susceptibility to alcoholic liver disease

OBJECTIVE

There is substantial inter-individual diversity in the susceptibility of alcoholics to liver injury. Alterations of intestinal microbiota (IM) have been reported in alcoholic liver disease (ALD), but the extent to which they are merely a consequence or a cause is unknown. We aimed to demonstrate that a specific dysbiosis contributes to the development of alcoholic hepatitis (AH).

DESIGN

We humanised germ-free and conventional mice using human IM transplant from alcoholic patients with or without AH. The consequences on alcohol-fed recipient mice were studied.

RESULTS

A specific dysbiosis was associated with ALD severity in patients. Mice harbouring the IM from a patient with severe AH (sAH) developed more severe liver inflammation with an increased number of liver T lymphocyte subsets and Natural Killer T (NKT) lymphocytes, higher liver necrosis, greater intestinal permeability and higher translocation of bacteria than mice harbouring the IM from an alcoholic patient without AH (noAH). Similarly, CD45+ lymphocyte subsets were increased in visceral adipose tissue, and CD4(+)T and NKT lymphocytes in mesenteric lymph nodes. The IM associated with sAH and noAH could be distinguished by differences in bacterial abundance and composition. Key deleterious species were associated with sAH while the Faecalibacterium genus was associated with noAH. Ursodeoxycholic acid was more abundant in faeces from noAH mice. Additionally, in conventional mice humanised with the IM from an sAH patient, a second subsequent transfer of IM from an noAH patient improved alcohol-induced liver lesions.

CONCLUSIONS

Individual susceptibility to ALD is substantially driven by IM. It may, therefore, be possible to prevent and manage ALD by IM manipulation.

IL-22BP is produced by eosinophils in human gut and blocks IL-22 protective actions during colitis

Crohn's disease and ulcerative colitis, the two major forms of inflammatory bowel diseases (IBDs), are characterized by high levels of IL-22 production. Rodent studies revealed that this cytokine is protective during colitis but whether this is true in IBDs is unclear. We show here that levels of the soluble inhibitor of IL-22, interleukin 22-binding protein (IL-22BP), are significantly enhanced during IBDs owing to increased numbers of IL-22BP-producing eosinophils, that we unexpectedly identify as the most abundant source of IL-22BP protein in human gut. In addition, using IL-22BP-deficient rats, we confirm that endogenous IL-22BP is effective at blocking protective actions of IL-22 during acute colitis. In conclusion, our study provides new important insights regarding the biology of IL-22 and IL-22BP in the gut and indicates that protective actions of IL-22 are likely to be suboptimal in IBDs thus making IL-22BP a new relevant therapeutic target.

Chronic eccentric cycling improves quadriceps muscle structure and maximum cycling power

An interesting finding from eccentric exercise training interventions is the presence of muscle hypertrophy without changes in maximum concentric strength and/or power. The lack of improvements in concentric strength and/or power could be due to long lasting suppressive effects on muscle force production following eccentric training. Thus, improvements in concentric strength and/or power might not be detected until muscle tissue has recovered (e. g., several weeks post-training). We evaluated alterations in muscular structure (rectus-femoris, RF, and vastus lateralis, VL, thickness and pennation angles) and maximum concentric cycling power (Pmax) 1-week following 8-weeks of eccentric cycling training (2×/week; 5-10.5 min; 20-55% of Pmax). Pmax was assessed again at 8-weeks post-training. At 1 week post-training, RF and VL thickness increased by 24±4% and 13±2%, respectively, and RF and VL pennation angles increased by 31±4% and 13±1%, respectively (all P<0.05). Compared to pre-training values, Pmax increased by 5±1% and 9±2% at 1 and 8 weeks post-training, respectively (both P<0.05). These results demonstrate that short-duration high-intensity eccentric cycling can be a time-effective intervention for improving muscular structure and function in the lower body of healthy individuals. The larger Pmax increase detected at 8-weeks post-training implies that sufficient recovery might be necessary to fully detect changes in muscular power after eccentric cycling training.

A dairy fat matrix providing alpha-linolenic acid (ALA) is better than a vegetable fat mixture to increase brain DHA accretion in young rats

Achieving an appropriate DHA status in the neonatal brain is an important goal of neonatal nutrition. We evaluated how alpha-linolenic acid (ALA), provided for six weeks after weaning by different dietary fat matrix, improved brain DHA content of young male rats born from deficient-dams. The level of ALA achieved was based on the fat composition of usual infant vegetable formula. A palm oil-blend diet thus providing 1.5%ALA was compared to dairy fat-blend-based diets that provided either 1.5%ALA or 2.3%ALA, or a rapeseed oil diet providing 8.3%ALA (n-6/n-3 ratio were, respectively 10,10,5,2.5). The 1.5%ALA-dairy-fat-blend was superior to 1.5%ALA-palm-oil-blend to restore values of brain DHA, while the 2.3%ALA-dairy-fat-blend exhibited a further increase and reached the values obtained with pure rapeseed diet (8.3%ALA). Dairy-fat-blends enriched with ALA appear to be an interesting strategy for achieving optimal DHA levels in the brain of post-weaning rats. Providing dairy fat as well as a reduction of the LA/ALA ratio should be reconsidered to design infant formula.

Gut microbiota-derived propionate reduces cancer cell proliferation in the liver

Background:

Metabolites released by the gut microbiota may influence host metabolism and immunity. We have tested the hypothesis that inulin-type fructans (ITF), by promoting microbial production of short-chain fatty acids (SCFA), influence cancer cell proliferation outside the gut.

Methods:

Mice transplanted with Bcr-Abl-transfected BaF3 cells, received ITF in their drinking water. Gut microbiota was analysed by 16S rDNA polymerase chain reaction (PCR)–denaturing gradient gel electrophoresis (DGGE) and qPCR. Serum Short-chain fatty acids were quantified by UHPLC-MS. Cell proliferation was evaluated in vivo, by molecular biology and histology, and in vitro.

Results:

Inulin-type fructans treatment reduces hepatic BaF3 cell infiltration, lessens inflammation and increases portal propionate concentration. In vitro, propionate reduces BaF3 cell growth through a cAMP level-dependent pathway. Furthermore, the activation of free fatty acid receptor 2 (FFA2), a Gi/Gq-protein-coupled receptor also known as GPR43 and that binds propionate, lessens the proliferation of BaF3 and other human cancer cell lines.

Conclusion:

We show for the first time that the fermentation of nutrients such as ITF into propionate can counteract malignant cell proliferation in the liver tissue. Our results support the interest of FFA2 activation as a new strategy for cancer therapeutics. This study highlights the importance of research focusing on gut microbes–host interactions for managing systemic and severe diseases such as leukaemia.

Functional dysbiosis within the gut microbiota of patients with constipated-irritable bowel syndrome

BACKGROUND

The role of the gut microbiota in patho-physiology of irritable bowel syndrome (IBS) is suggested by several studies. However, standard cultural and molecular methods used to date have not revealed specific and consistent IBS-related groups of microbes.

AIM

To explore the constipated-IBS (C-IBS) gut microbiota using a function-based approach.

METHODS

The faecal microbiota from 14 C-IBS women and 12 sex-match healthy subjects were examined through a combined strictly anaerobic cultural evaluation of functional groups of microbes and fluorescent in situ hybridisation (16S rDNA gene targeting probes) to quantify main groups of bacteria. Starch fermentation by C-IBS and healthy faecal samples was evaluated in vitro.

RESULTS

In C-IBS, the numbers of lactate-producing and lactate-utilising bacteria and the number of H(2) -consuming populations, methanogens and reductive acetogens, were at least 10-fold lower (P < 0.05) compared with control subjects. Concomitantly, the number of lactate- and H(2) -utilising sulphate-reducing population was 10 to 100 fold increased in C-IBS compared with healthy subjects. The butyrate-producing Roseburia - E. rectale group was in lower number (0.01 < P < 0.05) in C-IBS than in control. C-IBS faecal microbiota produced more sulphides and H(2) and less butyrate from starch fermentation than healthy ones.

CONCLUSIONS

A major functional dysbiosis was observed in constipated-irritable bowel syndrome gut microbiota, reflecting altered intestinal fermentation. Sulphate-reducing population increased in the gut of C-IBS and were accompanied by alterations in other microbial groups. This could be responsible for changes in the metabolic output and enhancement in toxic sulphide production which could in turn influence gut physiology and contribute to IBS pathogenesis.

Alterations of single molecule fluorescence lifetimes in near-field optical microscopy

Fluorescence lifetimes of single Rhodamine 6G molecules on silica surfaces were measured with pulsed laser excitation, time-correlated single photon counting, and near-field scanning optical microscopy (NSOM). The fluorescence lifetime varies with the position of a molecule relative to a near-field probe. Qualitative features of lifetime decreases are consistent with molecular excited state quenching effects near metal surfaces. The technique of NSOM provides a means of altering the environment of a single fluorescent molecule and its decay kinetics in a repeatable fashion.

Limitations of relaxation kinetics on muscular work

AIM

Positive net work produced during cyclic contractions is partially limited by relaxation kinetics, which to date, have not been directly investigated. Therefore, the purpose of this investigation was to determine the influence of relaxation kinetics on cyclic work.

METHODS

Soleus muscles of four cats were isolated and subjected to a series of work loops (0.5, 1, 1.5 and 2 Hz cycle frequencies) during which stimulation terminated prior to the end of the shortening phase to allow for complete muscle relaxation and matched discrete sinusoidal shortening contractions during which stimulation remained on until the completion of the shortening phase. Muscle length changes during these protocols were centred on optimum length and were performed across muscle lengths that represented walking gait.

RESULTS

When muscle excursions were centred on L(o) relaxation kinetics decreased muscular work by 2.8 + or - 0.8%, 12.1 + or - 4.1%, 27.9 + or - 4.5% and 40.1 + or - 5.9% for 0.5, 1, 1.5 and 2 Hz respectively. However, relaxation kinetics did not influence muscular work when muscle excursions represented walking gait. In addition, muscular work produced at muscle lengths associated with walking gait was less than the work produced across L(o) (55.7 + or - 20.0%, 53.5 + or - 21.0%, and 50.1 + or - 22.0% for 0.5, 1 and 1.5 Hz respectively).

CONCLUSION

These results imply that relaxation kinetics are an important factor that limit the ability of muscle to produce work; however, the influence of relaxation kinetics on physiological function may depend on the relation between the optimum length and natural excursion of a muscle.

Techniques for flow cytometer alignment

This unit provides essential knowledge for correctly using any flow cytometer to ensure that data collected are accurate and reliable. Two levels of system alignment are described: routine alignment checks and complete alignment, both of which can be applied to a variety of instrument configurations.

Degradation and utilization of xylans by the rumen anaerobe Prevotella bryantii (formerly P. ruminicola subsp. brevis) B(1)4

Freshly harvested whole cells from cultures of P. bryantii B(1)4 grown with oat spelt xylan (OSX) as an energy source showed less than 25% of the enzyme activity against OSX, and less than 15% of the activity against birchwood xylan (BWX) and carboxymethylcellulose, that was detectable in sonicated cell preparations. This indicates that much of this hydrolytic activity is either periplasmic, membrane-associated or intracellular and may be concerned with the processing of transported oligosaccharides.P. bryantii B(1)4 cultures were able to utilise up to 45% and 51% of the total pentose present in OSX and BWX, respectively, after 24 h, but could utilize 84% of a water-soluble fraction of BWX. Analysis of the xylan left undegraded after incubation with P. bryantii showed that while xylose and arabinose were removed to a similar extent, uronic acids were utilized to a greater extent than xylose. Predigestion of xylans with two cloned xylanases from the cellulolytic rumen anaerobe Ruminococcus flavefaciens gave little increase in overall pentose utilization suggesting that external P. bryantii xylanases are as effective as the cloned R. flavefaciens enzymes in releasing products that can be utilised by P. bryantii cells. The xylanase system of P. bryantiiis able to efficiently utilise not only xylo-oligosaccharides but also larger water-soluble xylan fragments.

Use of clinical risk factors to identify postmenopausal women with vertebral fractures

INTRODUCTION AND HYPOTHESIS

Previous studies have been unable to identify risk factors for prevalent vertebral fractures (VF), which are suitable for use in selection strategies intended to target high-risk sub-groups for diagnostic assessment. However, these studies generally consisted of large epidemiology surveys based on questionnaires and were only able to evaluate a limited number of risk factors. Here, we investigated whether a stronger relationship exists with prevalent VF when conventional risk factors are combined with additional information obtained from detailed one-to-one assessment.

METHODS

Women aged 65-75 registered at four geographically distinct GP practices were invited to participate (n=1,518), of whom 540 attended for assessment as follows: a questionnaire asking about risk factors for osteoporosis such as height loss compared to age 25 and history of non-vertebral fracture (NVF), the get-up-and-go test, Margolis back pain score, measurement of wall-tragus and rib-pelvis distances, and BMD as measured by the distal forearm BMD. A lateral thoraco-lumbar spine X-ray was obtained, which was subsequently scored for the presence of significant vertebral deformities.

RESULTS

Of the 509 subjects who underwent spinal radiographs, 37 (7.3%) were found to have one or more VF. Following logistic regression analysis, the four most predictive clinical risk factors for prevalent VF were: height loss (P=0.006), past NVF (P=0.004), history of back pain (P=0.075) and age (P=0.05). BMD was also significantly associated with prevalent VF (P=0.002), but its inclusion did not affect associations with other variables. Factors elicited from detailed one-to-one assessment were not related to the risk of one or more prevalent VFs. The area under ROC curves derived from these regressions, which suggested that models for prevalent VF had modest predictive accuracy, were as follows: 0.68 (BMD), 0.74 (four clinical risk factors above) and 0.78 (clinical risk factors + BMD). Analyses were repeated in relation to the subgroup of 13 patients with two or more VFs, which revealed that in this instance, the Margolis back pain score and rib-pelvis distance were associated with the presence of multiple VFs (P=0.022 and 0.026, respectively). Moreover, the predictive value as reflected by the ROC curve area was improved: 0.80 (BMD), 0.88 (the four most predictive clinical risk factors consisting of the height loss, past NVF, Margolis back pain score and rib-pelvis distance) and 0.91 (clinical risk factors + BMD).

CONCLUSIONS

Evaluation of additional risk factors from detailed one-to-one assessment does not improve the predictive value of risk factors for one or more prevalent vertebral deformities in postmenopausal women. However, the use of factors such as the Margolis back pain score and rib-pelvis distance may be helpful in identifying postmenopausal women at high risk of multiple prevalent VFs.

Using a representative sample of workers for constructing the SUMEX French general population based job-exposure matrix

BACKGROUND

Job-exposure matrices (JEMs) applicable to the general population are usually constructed by using only the expertise of specialists.

AIMS

To construct a population based JEM for chemical agents from data based on a sample of French workers for surveillance purposes.

METHODS

The SUMEX job-exposure matrix was constructed from data collected via a cross-sectional survey of a sample of French workers representative of the main economic sectors through the SUMER-94 survey: 1205 occupational physicians questioned 48 156 workers, and inventoried exposure to 102 chemicals. The companies' economic activities and the workers' occupations were coded according to the official French nomenclatures. A segmentation method was used to construct job groups that were homogeneous for exposure prevalence to chemical agents. The matrix was constructed in two stages: consolidation of occupations according to exposure prevalence; and establishment of exposure indices based on individual data from all the subjects in the sample.

RESULTS

An agent specific matrix could be constructed for 80 of the chemicals. The quality of the classification obtained for each was variable: globally, the performance of the method was better for less specific and therefore more easy to assess agents, and for exposures specific to certain occupations.

CONCLUSIONS

Software has been developed to enable the SUMEX matrix to be used by occupational physicians and other prevention professionals responsible for surveillance of the health of the workforce in France.

Fat-depleted CLA-treated mice enter torpor after a short period of fasting

Resting energy expenditure (Resting-EE), EE with treadmill exercise, and post-prandial thermogenesis were continuously monitored by indirect calorimetry during a 24 h recording session in control (CT) and CLA-treated (CLA) (1% CLA in the food, by weight) C57Bl/6 male mice. After 15 days of CLA treatment, the fat content of CLA mice had fallen to 20% of that in CT mice. CLA mice were able to face the energy challenge of exercise but used less lipid than CT mice. Resting-EE values fell during the post-exercise period. The thermogenic response to a calibrated test meal given 5 h after the run abolished the differences in EE and substrate oxidation between CT and CLA mice. However, 2.5 h after ingestion of the test meal onward, CT mice gradually increased their lipid oxidation to sustain resting-EE levels. In contrast, CLA mice did not increase their lipid oxidation and their resting-EE levels fell significantly until they entered into torpor. Blood leptin was low but similar in CT and CLA-treated mice suggesting that leptin is not critical to induce torpor. We suggest that the durable inhibition of lipid oxidation in fasting CLA mice was an adaptive behaviour devoted at sparing the residual adipose deposits.

No Differences in Cycling Efficiency Between World-Class and Recreational Cyclists

The aim of this experiment was to compare the efficiency of elite cyclists with that of trained and recreational cyclists. Male subjects (N = 69) performed an incremental exercise test to exhaustion on an electrically braked cycle ergometer. Cadence was maintained between 80 - 90 rpm. Energy expenditure was estimated from measures of oxygen uptake (VO (2)) and carbon dioxide production (VCO(2)) using stoichiometric equations. Subjects (age 26 +/- 7 yr, body mass 74.0 +/- 6.3 kg, Wpeak 359 +/- 40 W and VO(2)peak 62.3 +/- 7.0 mL/kg/min) were divided into 3 groups on the basis of their VO (2)peak (< 60.0 (Low, N = 26), 60 - 70 (Med, N = 27) and > 70 (High, N = 16) mL/kg/min). All data are mean +/- SE. Despite the wide range in aerobic capacities gross efficiency (GE) at 165 W (GE (165)), GE at the same relative intensity (GE (final)), delta efficiency (DE) and economy (EC) were similar between all groups. Mean GE (165) was 18.6 +/- 0.3 %, 18.8 +/- 0.4 % and 17.9 +/- 0.3 % while mean DE was 22.4 +/- 0.4 %, 21.6 +/- 0.4 % and 21.2 +/- 0.5 % (for Low, Medium and High, respectively). There was no correlation between GE (165), GE (final), DE or EC and VO(2)peak. Based on these data, we conclude that there are no differences in efficiency and economy between elite cyclists and recreational level cyclists.

Determinants of metabolic cost during submaximal cycling

The metabolic cost of producing submaximal cycling power has been reported to vary with pedaling rate. Pedaling rate, however, governs two physiological phenomena known to influence metabolic cost and efficiency: muscle shortening velocity and the frequency of muscle activation and relaxation. The purpose of this investigation was to determine the relative influence of those two phenomena on metabolic cost during submaximal cycling. Nine trained male cyclists performed submaximal cycling at power outputs intended to elicit 30, 60, and 90% of their individual lactate threshold at four pedaling rates (40, 60, 80, 100 rpm) with three different crank lengths (145, 170, and 195 mm). The combination of four pedaling rates and three crank lengths produced 12 pedal speeds ranging from 0.61 to 2.04 m/s. Metabolic cost was determined by indirect calorimetery, and power output and pedaling rate were recorded. A stepwise multiple linear regression procedure selected mechanical power output, pedal speed, and pedal speed squared as the main determinants of metabolic cost (R(2) = 0.99 +/- 0.01). Neither pedaling rate nor crank length significantly contributed to the regression model. The cost of unloaded cycling and delta efficiency were 150 metabolic watts and 24.7%, respectively, when data from all crank lengths and pedal speeds were included in a regression. Those values increased with increasing pedal speed and ranged from a low of 73 +/- 7 metabolic watts and 22.1 +/- 0.3% (145-mm cranks, 40 rpm) to a high of 297 +/- 23 metabolic watts and 26.6 +/- 0.7% (195-mm cranks, 100 rpm). These results suggest that mechanical power output and pedal speed, a marker for muscle shortening velocity, are the main determinants of metabolic cost during submaximal cycling, whereas pedaling rate (i.e., activation-relaxation rate) does not significantly contribute to metabolic cost.

A comparative study to assess the clinical use of Fluorescein Meniscus Time (FMT) with Tear Break up Time (TBUT) and Schirmer's tests (ST) in the diagnosis of dry eyes

INTRODUCTION

The clinical diagnosis of dry-eye is confirmed by a suitable test of tear production and the technique commonly used today to diagnose dry eye is the Schirmer's test (ST). Although the ST is easy to perform it gives variable results, poor reproducibility and low sensitivity for detecting dry eyes. Another test, the tear break up time (TBUT) is used to assess the stability of tears which if abnormal may also cause symptomatic dry-eye. We present the results of both these tests and a new test, which shows greater sensitivity than the ST in detecting aqueous tear deficiency. The fluorescein meniscus time (FMT) is a new test developed in conjunction with one of the authors (CL) and the Department of Ophthalmology at the University Hospital of Wales. The FMT is a measure of the rate at which a fluorescent tear meniscus is formed using 2% sodium fluorescein, a stopwatch and suitable illumination with a slit lamp.

METHOD

An open controlled study in 62 patients and 51 controls was conducted to compare the ability of ST, FMT and TBUT to detect dry-eye in a group of patients diagnosed with rheumatoid arthritis and symptomatic dry eyes for a minimum period of 6 months. A separate control group of 15 subjects was tested on three separate occasions to assess the reproducibility of the FMT test.

RESULTS

All three tests showed a statistically significant difference between the patient and control populations; Mann-Whitney P < 0.001. There was a correlation between the right and left eye for all three tests in the control group (ST r(2) = 0.77, FMT r(2) = 0.98, TBUT r(2) = 0.94). This correlation was markedly reduced for FMT and TBUT in the patient population and was in keeping with the symptoms reported as being worse on one side in a proportion of the patients (FMT r(2) = 0.52, TBUT r(2) = 0.54, ST r(2) = 0.75). A correlation with age was also observed for all the three tests in the control group (ST r(2) = 0.74, FMT r(2)= 0.92, TBUT r(2) = 0.51), but not in the patient population (ST r(2) = 0.06, FMT r(2) = 0.18, TBUT r(2) = 0.03). A significant correlation was observed between the ST and FMT in both the control (ST vs FMT r(2) = 0.65) and patient population (ST vs FMT r(2) = 0.44). There was no value greater than 200 seconds for FMT recorded in the control group. Using this value to define an abnormal FMT, 85% of the patients (72% of the eyes tested) had an abnormal result. This was in contrast to 35% of patients (26% of the eyes tested) with abnormal results detected by ST. Using ANOVA and Student's paired t-test, there were no significant differences between the three sets of values recorded serially over 3 months to assess the reproducibility of the FMT. The average standard error of the mean was 2.72% and the average co-efficient of variation 4.07%.

CONCLUSION

Our study suggests that the FMT is a more sensitive test with good reproducibility compared to the Schirmer's test. The FMT correlates with the ST and suggests that both tests measure aqueous tear deficiency. The FMT therefore is a better alternative to ST currently being used to test aqueous tear deficiency.

Bronchial challenge with flour: early response is dependent on the dose of activated allergen inhaled

Specific bronchial challenges provide information about the relationship between inhaled dose of allergen and change in lung function, but the intermediate pathways remain largely obscure. The aim of this study was to investigate the relationships between the early asthmatic response and 1) the inhaled dose of wheat flour, 2) the concentration of wheat flour, 3) the duration of the exposure, and 4) the deactivation of inhaled allergens and mediators. Thirty-one patients with occupational asthma to wheat flour were studied. Particle aerosols were generated by a computer-controlled aerosoliser and the results were expressed as the provocative dose causing a 20% fall in forced expiratory volume in one second (FEVi) (PD20). The cumulative dose (from the beginning of the challenge), the last inhaled dose, and an estimated dose (taking into account exponential deactivation), were calculated. Twenty patients had high reactivity to flour (reaching a PD20 value). Eleven patients had intermediate reactivity (no measurable PD20 but significantly greater fall in FEV1 compared with lactose challenge). A better correlation between change in FEV1 and dose was obtained for the estimated dose than for the cumulative or last inhaled dose. The bronchial response to wheat flour can be measured by the individual specific hyperreactivity and is expressed by provocative dose of flour. However, deactivation of the allergen and mediators has to be taken into account. This problem can be addressed by using a mathematical model.

Indirect effects of heavy metals on parasites may cause shifts in snail species compositions

We studied the direct and indirect effects of pollution on the distributions and abundances of two closely related species of pulmonate freshwater snails. Physella columbiana is more numerous at heavy metal-polluted lakes, and Lymnaea palustris is more numerous at reference lakes. Both species are present at all sites, as are predatory bluegill sunfish (Lepomis macrochirus). The direct effects examined included the snails' growth and reproduction in both the presence and absence of heavy metals and their short-term survival when exposed to large concentrations of heavy metals. The indirect effects were the species' ability to elude capture by sunfish and the diversity and abundance of parasites within the snails. We found that heavy metals had little direct effect on growth and reproduction and that both species acquired similar levels of metals in their tissues. Interestingly, P. columbiana (the more abundant species in polluted lakes) actually exhibited higher recruitment in the absence of metals than did L. palustris (reference lakes). L. palustris has life history characteristics that favor increased growth and reduced reproduction. These characteristics resulted in decreased predation of adults by gape-limited predators and a greater ability to cope with heavy parasite burdens. P. columbiana exhibited slower growth, which resulted in increased predation although higher reproduction rates may compensate.The major effect of heavy metals on species distributions was indirect on the snails' parasites. Parasites appeared to be very susceptible to metals, and this resulted in lower parasite diversity and intensities at polluted sites for both species of snails. P. columbiana may only be able to outcompete L. palustris at polluted sites due to the indirect effects of heavy metals; the negative effect of heavy metals on parasites, and a proposed negative effect of metals on the foraging ability of sunfish that favors the faster-reproducing P. columbiana.

Lifestyle behaviors affect cardiovascular risk status in men 1 year after kidney transplantation

Persons with end-stage renal disease have an accelerated risk for cardiovascular (CV) morbidity and mortality. Unfortunately, their accelerated CV risk persists even after kidney transplantation associated with pretransplant and post-transplant vascular disease. number of rejections treated with high-dose steroids, prolonged use of immunosuppressive therapy post-transplant, effects of comorbid chronic conditions and male gender. Unhealthy, modifiable lifestyle practices often augment their CV risk. The purpose of this study was to examine health-related lifestyle behaviors and estimate CV risks of men 1 year following kidney transplantation. Using the Healthier People Network Health Risk Appraisal (HPN-HRA), we examined CV risk characteristics of 34 men (M age=47.3 years) enrolled in an urban, mid-southern transplant center. Participants were assessed via self-administered paper-and-pencil questionnaires and medical record review provided biological data for analyses. HPN-HRA software was used to analyze biological and behavioral characteristics to compute CV risk estimates. Data were analyzed using descriptive, inferential and correlational analyses. The majority of participants reported smoke cessation (n= 19) or never having smoked (n = 8), and consumption of one or less alcoholic drinks per week (n=28). On the other hand, increased risk for heart attack and stroke were associated with advancing age (P<0.0001), white race (P<0.05) and higher systolic blood pressure (P<0.01). While risk for heart attack was associated with current cigarette smoking (P<0.01), risk for stroke was not. Conversely, risk for stroke was associated with higher BMI (P<0.05), risk for heart attack was not. Thus, the study provides evidence that male kidney transplant survivors exhibit a significant number of non-modifiable and modifiable characteristics that contribute to their posttransplant CV risk.