Occupational stress and musculoskeletal disorders in firefighters: the mediating effect of depression and job burnout.

The firefighting profession carries a heightened risk of musculoskeletal disorders. A firefighter's job is physically demanding and includes activities such as running, climbing, dragging, and lifting. Often, these tasks are unpredictable, performed in harsh environments, and have been found to cause psychological stress. The purpose of this study was to investigate the effects of occupational stress on work-related musculoskeletal disorders (WRMSD) in firefighters. In addition, the mediating effects of depression and job burnout on proposed relationships were examined. Data informing this study were collected using a survey questionnaire. The survey questionnaire included the Beck Depression Inventory, the Center for Epidemiological Studies Depression Scale (CES-D), the Maslach Burnout Inventory, the Post Traumatic Stress Disorder Inventory (PCL), and the Nordic Musculoskeletal Questionnaire. Collected data were analyzed using structural equation modeling approach in AMOS. The results of the 2339 responding firefighters suggest that work related stress is positively related to WRMSDs in firefighters and can lead to musculoskeletal symptoms through four paths, being emotional exhaustion, personal accomplishment, CES-D total score, and depersonalization. Through depersonalization, job stress had the most significant impact on musculoskeletal symptoms (coefficient = 0.053). Furthermore, the results showed that post-traumatic stress disorders (PTSD) can affect musculoskeletal symptoms through ten paths, again through depersonalization, PTSD had the most significant impact on musculoskeletal symptoms (coefficient = 0.141). The results of this study suggest that organizations should design interventions and policies to prevent and manage occupational stress, depression, and job burnout to negate its undesired consequences on firefighters' health (i.e. WRMSD).

Relationships between job stress, post-traumatic stress and musculoskeletal symptoms in firefighters and the role of job burnout and depression mediators: a bayesian network model.

INTRODUCTION: Job stress, post-traumatic stress disorder (PTSD), and negative psychological outcomes in firefighters can be caused, or aggravated, by their work. These mental disorders can impart musculoskeletal symptoms. This study aimed to investigate relationships between musculoskeletal and psychological disorders in a population of firefighters using a Bayesian network model. METHODS: This cross-sectional study, conducted in 2022, included 2339 firefighters who completed questionnaires during their rest periods. The questionnaires comprised of demographical information, the Occupational Stress Questionnaire-HSE, the PTSD Checklist, Maslach Burnout Inventory, Center for Epidemiologic Studies - Depression scale (CES-D), and Nordic Musculoskeletal Questionnaire. GeNIe academic software was used to analyze the Bayesian network. RESULTS: High job stress and high PTSD each increased the probability of musculoskeletal symptoms by 34%. When combined, high job stress and high PTSD increased the probability of musculoskeletal symptoms by 37%. Among the mediator's burnout and depression, depression had the highest association with musculoskeletal symptoms. CONCLUSIONS: Job stress and PTSD can increase musculoskeletal symptoms and are influenced by psychological mediators (like burnout and depression). Adopting preventive and therapeutic measures to mitigate job stress and PTSD, mitigate and rehabilitate WMSD, and manage associated mediators are critical for the mental and physical health of firefighters.

Acidic Osteoid Templates the Plywood Structure of Bone Tissue.

Bone is created by osteoblasts that secrete osteoid after which an ordered texture emerges, followed by mineralization. Plywood geometries are a hallmark of many trabecular and cortical bones, yet the origin of this texturing in vivo has never been shown. Nevertheless, extensive in vitro work revealed how plywood textures of fibrils can emerge from acidic molecular cholesteric collagen mesophases. This study demonstrates in sheep, which is the preferred model for skeletal orthopaedic research, that the deeper non-fibrillar osteoid is organized in a liquid-crystal cholesteric geometry. This basophilic domain, rich in acidic glycosaminoglycans, exhibits low pH which presumably fosters mesoscale collagen molecule ordering in vivo. The results suggest that the collagen fibril motif of twisted plywood matures slowly through self-assembly thermodynamically driven processes as proposed by the Bouligand theory of biological analogues of liquid crystals. Understanding the steps of collagen patterning in osteoid-maturation processes may shed new light on bone pathologies that emerge from collagen physico-chemical maturation imbalances.

The global prevalence of musculoskeletal disorders among firefighters: a systematic review and meta-analysis.

This systematic review and meta-analysis study aimed to explore the global prevalence of musculoskeletal disorders (MSDs) among firefighters. A systematical search was performed in three international academic databases (Scopus, PubMed and Web of Science). Overall, 31 articles were included in this review. The pooled prevalence of total MSDs in firefighters was identified as 41% (95% confidence interval [CI] [33, 50]). The prevalence of MSDs in neck, shoulders, upper back, lower back, upper extremity and lower extremity was 9% (95% CI [7, 10]), 11% (95% CI [8, 15]), 8% (95% CI [5, 12]), 31% (95% CI [27, 34]), 13% (95% CI [9, 17]) and 16% (95% CI [14, 18]), respectively. No statistically significant relationship was observed between prevalence of MSDs and year of study, mean age, size of sample, duration of prevalence, region or income level. Demographic, occupational and medical condition factors were identified that can create these disorders among firefighters.

Monitoring the Spatial and Interannual Dynamic of Zostera noltei.

Seagrass is a vital structural and functional element of the marine environment worldwide and is highly valued for its ecological benefits. Monitoring the evolution of the seagrass habitat is essential to understand how this coastal ecosystem changes, and to develop good environmental management practices. For the present study, two remote sensing methods were used to map and monitor Zostera noltei Hornemann, 1832 (Z. noltei), in the Merja Zerga lagoon from 2010 to 2020. These methods which are the random forest algorithm and the object-oriented classification, were convenient to provide significant results. The first approach employed Sentinel-2 images from 2018 to 2020, which were used to extract information on changes in Z. noltei (commonly called dwarf eelgrass) distribution and aboveground biomass estimation. The second involved three orthophotography (orthophoto) mosaics from the years 2010, 2016, and 2018, which were analyzed to map the distribution of the species. It was revealed that Z. noltei coverage has increased by 212 ha since 2010, with most of the growth occurring in the center and upstream part of the lagoon. The mean aboveground biomass of dwarf eelgrass in the lagoon was 78.5 DW/m² in 2018, 92.6 DW/m² in 2019, and 115.2 g DW/m² in 2020. The approach used in this study has provided important insights into the dynamic and mean biomass of Z. noltei in the Merja Zerga lagoon. It is therefore a valuable, non-destructive method that uses freely-available Sentinel-2 satellite data.

Global prevalence and associated factors of sleep disorders and poor sleep quality among firefighters: A systematic review and meta-analysis.

Lack of sleep can affect the health and performance of firefighters. This systematic review and meta-analysis estimated the global prevalence of sleep disorders and poor sleep quality among firefighters and reported associated factors. Four academic databases (Scopus, PubMed, Web of Science, and Embase) were systematically searched from January 1, 2000 to January 24, 2022. These databases were selected as they are known to index studies in this field. The search algorithm included two groups of keywords and all possible combinations of these words. The first group included keywords related to sleep and the second group keywords related to the firefighting profession. The relevant Joanna Briggs Institute checklist was used to evaluate study quality. Data from eligible studies were included in a meta-analysis. In total, 47 articles informed this review. The pooled prevalence of sleep disorders and poor sleep quality in firefighters were determined as 30.49% (95% CI [25.90, 35.06]) and 51.43% (95% CI [42.76, 60.10]), respectively. The results of a subgroup analysis showed that individuals in low- and middle-income countries (LMICs) had a higher prevalence of sleep disorders than those in high-income countries (HICs) but HICs had a higher prevalence of poor sleep quality than LMICs. Various factors, including shift work, mental health, injuries and pain, and body mass index were associated with sleep health. The findings of this review highlight the need for sleep health promotion programs in firefighters.

Chloe for COVID-19: Evolution of an Intelligent Conversational Agent to Address Infodemic Management Needs During the COVID-19 Pandemic.

There is an unprecedented demand for infodemic management due to rapidly evolving information about the novel COVID-19 pandemic. This viewpoint paper details the evolution of a Canadian digital information tool, Chloe for COVID-19, based on incremental leveraging of artificial intelligence techniques. By providing an accessible summary of Chloe's development, we show how proactive cooperation between health, technology, and corporate sectors can lead to a rapidly scalable, safe, and secure virtual chatbot to assist public health efforts in keeping Canadians informed. We then highlight Chloe's strengths, the challenges we faced during the development process, and future directions for the role of chatbots in infodemic management. The information presented here may guide future collaborative efforts in health technology in order to enhance access to accurate and timely health information to the public.

Collagen Suprafibrillar Confinement Drives the Activity of Acidic Calcium-Binding Polymers on Apatite Mineralization.

Bone collagenous extracellular matrix provides a confined environment into which apatite crystals form. This biomineralization process is related to a cascade of events partly controlled by noncollagenous proteins. Although overlooked in bone models, concentration and physical environment influence their activities. Here, we show that collagen suprafibrillar confinement in bone comprising intra- and interfibrillar spaces drives the activity of biomimetic acidic calcium-binding polymers on apatite mineralization. The difference in mineralization between an entrapping dentin matrix protein-1 (DMP1) recombinant peptide (rpDMP1) and the synthetic polyaspartate validates the specificity of the 57-KD fragment of DMP1 in the regulation of mineralization, but strikingly without phosphorylation. We show that all the identified functions of rpDMP1 are dedicated to preclude pathological mineralization. Interestingly, transient apatite phases are only found using a high nonphysiological concentration of additives. The possibility to combine biomimetic concentration of both collagen and additives ensures specific chemical interactions and offers perspectives for understanding the role of bone components in mineralization.

Origin of transparency in scattering biomimetic collagen materials.

Living tissues, heterogeneous at the microscale, usually scatter light. Strong scattering is responsible for the whiteness of bones, teeth, and brain and is known to limit severely the performances of biomedical optical imaging. Transparency is also found within collagen-based extracellular tissues such as decalcified ivory, fish scales, or cornea. However, its physical origin is still poorly understood. Here, we unveil the presence of a gap of transparency in scattering fibrillar collagen matrices within a narrow range of concentration in the phase diagram. This precholesteric phase presents a three-dimensional (3D) orientational order biomimetic of that in natural tissues. By quantitatively studying the relation between the 3D fibrillar network and the optical and mechanical properties of the macroscopic matrices, we show that transparency results from structural partial order inhibiting light scattering, while preserving mechanical stability, stiffness, and nonlinearity. The striking similarities between synthetic and natural materials provide insights for better understanding the occurring transparency.

A Short Synthesis of (+)-Brefeldin†C through Enantioselective Radical Hydroalkynylation.

A very concise total synthesis of (+)-brefeldin C starting from 2-furanylcyclopentene is described. This approach is based on an unprecedented enantioselective radical hydroalkynylation process to introduce the two cyclopentane stereocenters in a single step. The use of a furan substituent allows a high trans diastereoselectivity to be achieved during the radical process and it contains the four carbon atoms C1-C4 of the natural product in an oxidation state closely related to the one of the target molecule. The eight-step synthesis requires six product purifications and it provides (+)-brefeldin C in 18 % overall yield.

Photosynthetic epibionts and endobionts of Pacific oyster shells from oyster reefs in rocky versus mudflat shores.

The Pacific oyster, Crassostrea gigas (Thunberg), is the main bivalve species cultivated in the world. With global warming enabling its reproduction and larval survival at higher latitudes, this species is now recognized as invasive and creates wild oyster reefs globally. In this study, the spatial distribution of photosynthetic assemblages colonizing the shells of wild C. gigas was investigated on both a large scale (two contrasting types of reefs found in mudflats and rocky areas) and a small scale (within individual shells) using a hyperspectral imager. The microspatial distribution of all phototrophs was obtained by mapping the Normalized Difference Vegetation Index (NDVI). Second derivative (δδ) analyses of hyperspectral images at 462, 524, 571 and 647 nm were subsequently applied to map diatoms, cyanobacteria, rhodophytes and chlorophytes, respectively. A concomitant pigment analysis was carried out by high performance liquid chromatography and completed by taxonomic observations. This study showed that there was high microalgal diversity associated with wild oyster shells and that there were differences in the structure of the phototropic assemblages depending on the type of reef. Namely, vertically-growing oysters in mudflat areas had a higher biomass of epizoic diatoms (hyperspectral proxy at δδ462 nm) and were mainly colonized by species of the genera Navicula, Nitzschia and Hippodonta, which are epipelic or motile epipsammic. The assemblages on the horizontal oysters contained more tychoplanktonic diatoms (e.g. Thalassiosira pseudonana, T. proschkinae and Plagiogrammopsis vanheurckii). Three species of boring cyanobacteria were observed for both types of reef: Mastigocoleus testarum, Leptolyngbya terrebrans, and Hyella caespistosa, but the second derivative analysis at 524 nm showed a significantly higher biomass for the horizontally-growing oysters. There was no biomass difference for the boring chlorophyte assemblages (δδ647 nm), with two species: Eugomontia testarum and Ostreobium quekettii observed for both types of reef. This study shows that oyster shells are an idiosyncratic but ubiquitous habitat for phototrophic assemblages. The contribution of these assemblages in terms of biomass and production to the functioning of coastal areas, and particularly to shellfish ecosystems, remains to be evaluated.

The impact of body armor on physical performance of law enforcement personnel: a systematic review.

BACKGROUND: The law enforcement officer profession requires performance of arduous occupational tasks while carrying an external load, consisting of, at minimum, a chest rig, a communication system, weaponry, handcuffs, personal protective equipment and a torch. The aim of this systematic review of the literature was to identify and critically appraise the methodological quality of published studies that have investigated the impacts of body armour on task performance and to synthesize and report key findings from these studies to inform law enforcement organizations. METHODS: Several literature databases (Medline, CINAHL, SPORTDiscus, EMBAS) were searched using key search words and terms to identify appropriate studies. Studies meeting the inclusion criteria were critically evaluated using the Downs and Black protocol with inter-rater agreement determined by Cohen's Kappa. RESULTS: Sixteen articles were retained for evaluation with a mean Downs and Black score of 73.2 ± 6.8% (k = 0.841). Based on the research quality and findings across the included studies, this review determined that while effects of body armour on marksmanship and physiological responses have not yet been adequately ascertained, body armour does have significant physical performance and biomechanical impacts on the wearer, including: a) increased ratings of perceived exertion and increased time to complete functional tasks, b) decreased work capability (indicated by deterioration in fitness test scores), c) decreased balance and stability, and d) increased ground reaction forces. CONCLUSIONS: Given the physical performance and biomechanical impacts on the wearer, body armour should be carefully selected, with consideration of the physical fitness of the wearers and the degree to which the armour systems can be ergonomically optimized for the specific population in question.

Self-reported load carriage injuries of military soldiers.

The aim of this study was to investigate whether occupational load carriage constitutes a significant source of injury to military soldiers. An online survey was sent to soldiers serving in specific Australian Army Corps known to experience the greatest occupational exposure to load carriage. Of the 338 respondents, 34% sustained at least one load carriage injury. Fifty-two per cent of those injured during initial training reported sustaining an additional load carriage injury. The majority of injuries (61%) were to the lower limbs with bones and joints the most frequently injured body structures (39%). Endurance marching (continuous marching as part of a physical training session) was the activity accounting for most (38%) injuries. Occupational load carriage is associated with military soldier injuries and, once injured, soldiers are at a high risk of future load carriage injury. The bodily sites and nature of self-reported injuries in this study are akin to those of formally reported injuries and those of other militaries.

The impact of body armor on physical performance of law enforcement personnel: a systematic review

BACKGROUND: The law enforcement officer profession requires performance of arduous occupational tasks while carrying an external load, consisting of, at minimum, a chest rig, a communication system, weaponry, handcuffs, personal protective equipment and a torch. The aim of this systematic review of the literature was to identify and critically appraise the methodological quality of published studies that have investigated the impacts of body armour on task performance and to synthesize and report key findings from these studies to inform law enforcement organizations. METHODS: Several literature databases (Medline, CINAHL, SPORTDiscus, EMBAS) were searched using key search words and terms to identify appropriate studies. Studies meeting the inclusion criteria were critically evaluated using the Downs and Black protocol with inter-rater agreement determined by Cohen's Kappa. RESULTS: Sixteen articles were retained for evaluation with a mean Downs and Black score of 73.2 ± 6.8% (k = 0.841). Based on the research quality and findings across the included studies, this review determined that while effects of body armour on marksmanship and physiological responses have not yet been adequately ascertained, body armour does have significant physical performance and biomechanical impacts on the wearer, including: a) increased ratings of perceived exertion and increased time to complete functional tasks, b) decreased work capability (indicated by deterioration in fitness test scores), c) decreased balance and stability, and d) increased ground reaction forces. CONCLUSIONS: Given the physical performance and biomechanical impacts on the wearer, body armour should be carefully selected, with consideration of the physical fitness of the wearers and the degree to which the armour systems can be ergonomically optimized for the specific population in question.

The impact of fire suppression tasks on firefighter hydration: a critical review with consideration of the utility of reported hydration measures.

BACKGROUND: Firefighting is a highly stressful occupation with unique physical challenges, apparel and environments that increase the potential for dehydration. Dehydration leaves the firefighter at risk of harm to their health, safety and performance. The purpose of this review was to critically analyse the current literature investigating the impact of fighting 'live' fires on firefighter hydration. METHODS: A systematic search was performed of four electronic databases for relevant published studies investigating the impact of live fire suppression on firefighter hydration. Study eligibility was assessed using strict inclusion and exclusion criteria. The included studies were critically appraised using the Downs and Black protocol and graded according to the Kennelly grading system. RESULTS: Ten studies met the eligibility criteria for this review. The average score for methodological quality was 55 %, ranging from 50 % ('fair' quality) to 61 % ('good' quality) with a 'substantial agreement' between raters (k = .772). Wildfire suppression was considered in five studies and structural fire suppression in five studies. Results varied across the studies, reflecting variations in outcome measures, hydration protocols and interventions. Three studies reported significant indicators of dehydration resulting from structural fire suppression, while two studies found mixed results, with some measures indicating dehydration and other measures an unchanged hydration status. Three studies found non-significant changes in hydration resulting from wildfire firefighting and two studies found significant improvements in markers of hydration. Ad libitum fluid intake was a common factor across the studies finding no, or less severe, dehydration. CONCLUSIONS: The evidence confirms that structural and wildfire firefighting can cause dehydration. Ad libitum drinking may be sufficient to maintain hydration in many wildfire environments but possibly not during intense, longer duration, hot structural fire operations. Future high quality research better quantifying the effects of these influences on the degree of dehydration is required to inform policies and procedures that ensure firefighter health and safety.

Gender differences in load carriage injuries of Australian army soldiers.

BACKGROUND: With the removal of gender restrictions and the changing nature of warfare potentially increasing female soldier exposure to heavy military load carriage, the aim of this research was to determine relative risks and patterns of load carriage related injuries in female compared to male soldiers. METHODS: The Australian Defence Force Occupational Health, Safety and Compensation Analysis and Reporting workplace injury database was searched to identify all reported load carriage injuries. Using key search terms, the narrative description fields were used as the search medium to identify records of interest. Population estimates of the female: male incident rate ratio (IRR) were calculated with ninety-five percent confidence interval (95% CI) around the population estimate of each IRR determined. RESULTS: Female soldiers sustained 10% (n = 40) of the 401 reported injuries, with a female to male IRR of 1.02 (95% CI 0.74 to 1.41). The most common site of injury for both genders was the back (F: n = 11, 27%; M: n = 80, 22%), followed by the foot in female soldiers (n = 8, 20%) and the ankle (n = 60, 17%) in male soldiers. Fifteen percent (n = 6) of injuries in female soldiers and 6% (n = 23) of injuries in males were classified as Serious Personal Injuries (SPI) with the lower back the leading site for both genders (F: n = 3, 43%: M: n = 8, 29%). The injury risk ratio of SPI for female compared to male soldiers was 2.40 (95% CI 0.98 to 5.88). CONCLUSIONS: While both genders similarly have the lower back as the leading site of injury while carrying load, female soldiers have more injuries to the foot as the second leading site of injury, as opposed to ankle injuries in males. The typically smaller statures of female soldiers may have predisposed them to their observed higher risk of suffering SPI while carrying loads.

The Use of 2 Conditioning Programs and the Fitness Characteristics of Police Academy Cadets.

CONTEXT: Police academy training must physically prepare cadets for the rigors of their occupational tasks to prevent injury and allow them to adequately perform their duties. OBJECTIVE: To compare the effects of 2 physical training programs on multiple fitness measures in police cadets. DESIGN: Cohort study. SETTING: Police training academy. PATIENTS OR OTHER PARTICIPANTS: We collected data from 70 male (age = 27.4 ± 5.9 years, body weight = 85.4 ± 11.8 kg) and 20 female (age = 30.5 ± 5.8 years, body weight = 62.8 ± 11.0 kg) police cadets and analyzed data from 61 male cadets (age = 27.5 ± 5.5 years, body weight = 87.7 ± 13.2 kg). INTERVENTION(S): Participants completed one of two 6-month training programs. The randomized training group (RTG; n = 50), comprising 4 separate and sequential groups (n = 13, n = 11, n = 13, n = 13), completed a randomized training program that incorporated various strength and endurance exercises chosen on the day of training. The periodized group (PG; n = 11) completed a periodized training program that alternated specific phases of training. MAIN OUTCOME MEASURE(S): Anthropometric fitness measures were body weight, fat mass, and lean body mass. Muscular and metabolic fitness measures were 1-repetition maximum bench press, push-up and sit-up repetitions performed in 1 minute, vertical jump, 300-m sprint, and 2.4-km run. RESULTS: The RTG demonstrated improvements in all outcome measures between pretraining and posttraining; however, the improvements varied among the 4 individual RTGs. Conversely, the PG displayed improvements in only 3 outcome measures (push-ups, sit-ups, and 300-m sprint) but approached the level of significance set for this study (P < .01) in body weight, fat mass, and 1-repetition maximum bench press. CONCLUSIONS: Regardless of format, physical training programs can improve the fitness of tactical athletes. In general, physical fitness measures appeared to improve more in the RTG than in the PG. However, this observation varied among groups, and injury rates were not compared.

A functional movement screen profile of an Australian state police force: a retrospective cohort study.

BACKGROUND: Police officers are required to perform dynamic movements in unpredictable environments, the results of which can lead to injury. Early identification of poor movement patterns of a police population, and potential sub groups within this population, may provide opportunities to treat and minimise injury risks. The aim of this study was to profile the functional movement capabilities of an Australian state police force and potential sub groups through a retrospective cohort study. METHODS: Retrospective data from an Australian State Police Force were provided for analysis (♂ n = 1155, mean (±SD) age = 31.34 ± 8.41 years: ♀ n = 357, mean age = 27.99 ± 8.02 years). Data consisted of Functional Movement Screen (FMS) assessment results of male and female trainees and qualified police officers with all assessments conducted by a qualified Police Physical Training Instructor. RESULTS: Significantly higher (U = 253863, p < .001) FMS total scores were found for recruits (mean 15.23 ± SD 2.01 points) when compared to attested officers (14.57 ± 2.96 points) and differences in FMS total scores also approached significance for females (15.24 ± 2.35 points) when compared to males (14.84 ± 2.55 points, U = 186926, p = .007), with age found to be a key, significant factor in explaining these observed differences (F (1,1507) = 23.519, p < .001). The FMS components demonstrating poorest movement performance across all groups were the hurdle step and rotary stability. CONCLUSIONS: Generally, police personnel (both attested officers and recruits of both genders) of greater age have a lower functional movement capability when compared to younger personnel, with greater percentages scoring 14 or below on the FMS. Specific conditioning programs to improve strength, range of motion and stability during identified key movement types in those demonstrating poorer movement performance may serve to reduce injuries in police personnel.

Associations between anthropometric characteristics and physical performance in male law enforcement officers: a retrospective cohort study.

BACKGROUND: Police officers are often required to undertake physically demanding tasks, like lifting, dragging and pursuing a suspect. Therefore, physical performance is a key requirement. METHODS: Retrospective data for 76 male police officers (mean age = 39.42 ± 8.41 years; mean weight = 84.21 ± 12.91 kg) was obtained. Data included anthropometric (skinfolds, estimated percentage body fat, lean body mass and fat mass) and physical performance (1 Repetition Maximum Bench Press, 1-min sit-ups, 1-min push-ups, vertical jump, 300 m run, 1.5 mile run) measures and correlations between anthropometric measurement and fitness score were obtained. RESULTS: Estimated percentage body fat was significantly (p ≤ .001) and negatively correlated with all performance measures, except sit-ups and 300 m and 1.5 mile run performance. Estimated lean body mass was significantly and positively (p ≤ .001) correlated with push-ups, bench press and vertical jump measures, while increasing estimated fat mass was significantly (p ≤ .001) associated with reduced performance on sit-up, vertical jump, 1.5 mile run and estimated maximal voluntary oxygen uptake. CONCLUSIONS: A targeted approach, going beyond just decreasing percentage body fat to also selectively increasing lean mass, should be applied for optimal improvement in physical fitness performance.

Involvement of 3D osteoblast migration and bone apatite during in vitro early osteocytogenesis.

The transition from osteoblast to osteocyte is described to occur through passive entrapment mechanism (self-buried, or embedded by neighboring cells). Here, we provide evidence of a new pathway where osteoblasts are "more" active than generally assumed. We demonstrate that osteoblasts possess the ability to migrate and differentiate into early osteocytes inside dense collagen matrices. This step involves MMP-13 simultaneously with IBSP and DMP1 expression. We also show that osteoblast migration is enhanced by the presence of apatite bone mineral. To reach this conclusion, we used an in vitro hybrid model based on both the structural characteristics of the osteoid tissue (including its density, texture and three-dimensional order), and the use of bone-like apatite. This finding highlights the mutual dynamic influence of osteoblast cell and bone extra cellular matrix. Such interactivity extends the role of physicochemical effects in bone morphogenesis complementing the widely studied molecular signals. This result represents a conceptual advancement in the fundamental understanding of bone formation.