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Background: Regular physical activity (PA) promotes and excessive sedentary behavior (SB) deteriorates health. Yet the Finnish working-aged population spends most of the day sitting. A 1-year Moving To Business (MTB) -intervention supported small and medium-size workplaces to combat sedentariness. This paper reports the changes in employees' PA and SB from before MTB (baseline) to 1 year after baseline (follow-up)., Methods: Twelve workplaces with a total of 396 employees participated. Each workplace nominated a team to promote PA and reduce SB at organizational, working unit and employee level. The teams were mentored regionally through meetings, workshop and tools. Changes in PA and SB were assessed with a questionnaire and an accelerometer. Wald Confidence Interval (Cl) for a difference of proportions with matched pairs was used in the questionnaire data (%-points with 95% CI) and linear mixed model in the accelerometer data (minutes and % of wear-time with 95% CI)., Results: The mean age of the respondents to the questionnaire (N = 296; 75%) was 42.6 (SD 10.9), 64% were women, 95% had some education after high school, 74% worked in the day shift, 71% did sedentary work and 51% were overweight. The mean number of actions implemented in the workplaces was 6.8 and the multilevel approach was fully applied in 6 workplaces. Based on the questionnaire the time spent in SB decreased from baseline to follow-up 16% (95% CI -29 to -3) in total and 22% (-41 to -3) at work. The accelerometer showed daily increases of 33.7 min (15.3 to 52.1) and 6.8% (3.1 to 10.4) in total PA, 30.9 min (15.3 to 46.5) and 6.1% (2.9 to 9.2) in light PA and 673 (209 to 1139) more steps at work. Daily SB at work decreased 44.9 min (-68.0 to -21.8) and 7.6% (-11.9 to -3.2). Daily leisure PA declined 11.0 min (-24.9 to 2.9) and 3.2% (-6.2 to -0.2). Number of levels or actions had no effect on changes., Conclusions: Employees' PA increased and SB reduced at work during the intervention. At the same time leisure PA decreased slightly. Workplaces can achieve meaningful changes in employees' PA and SB if assisted systematically. Controlled studies are needed to confirm the present findings., Trial Registration: NCT01999205 , registration date 11/01/2013.

Objective: The aim of this study was to describe physiological load and psychological stress of Finnish firefighters during a 24-hour work shift., Methods: R-R intervals were recorded during 24-hour work shifts. Short-time Fourier transform was used to analyze heart rate variability during shifts., Results: HRmean, HRpeak, and square root of the mean of the sum of the squares of the differences between adjacent R-to-R peak intervals of the 24-hour shift was 73 ± 7 bpm (38 ± 4% of HRmax), 156 ± 16 bpm (82 ± 8% of HRmax), and 42 ± 14 ms. Mean VO2 was 11 ± 2 (% of VO2max) and VO2peak 72 ± 11 (% of VO2max)., Conclusions: Physiological load and psychological stress were temporarily high, even in young, fit firefighters. As the relative work load may increase and recovery processes slow down among aging employees, fatigue may occur unless work arrangements are well-designed.

The growing knowledge on the mechanisms of gene silencing and gene regulation by non-coding RNAs (ncRNA), mainly small interfering RNA (siRNA) and microRNA (miRNA), is providing a significant boost to the development of new therapeutic strategies for the treatment of cancer. However, the design of RNA-based therapeutics is hampered by biopharmaceutical issues, thus requiring the use of suitable delivery strategies. In this regards, lipid nanovectors have been successfully investigated to deliver RNA in different forms of cancer. Compared to other biomaterials, lipids offer advantages such as biocompatibility, biodegradability, easy production, low cost, limited toxicity and immunogenicity. The possibility to formulate these materials in the form of nanovectors allows overcoming biopharmaceutical issues associated to the therapeutic use of RNA, with the possibility to target tumors. This review takes stock of the main lipid nanovectors proposed to deliver ncRNA. For each considered delivery strategy, the rational design and the most meaningful in vitro and in vivo results are reported and discussed.

The chemokine CXCL12 activates CXCR4, initiating multiple pathways that control immune cell trafficking, angiogenesis and embryogenesis; CXCR4 is also overexpressed in multiple tumors affecting metastatic dissemination. While there has been great enthusiasm for exploiting the CXCR4-CXCL12 axis as a target in cancer therapy, to date the promise has yet to be fulfilled. A new class of CXCR4-antagonist cyclic peptides was recently developed and the compound named Peptide R was identified as the most active. With the intent to improve the efficacy and biodistribution of Peptide R, stealth liposomes decorated with Peptide R were developed (PL-Peptide R). In vitro PL-Peptide R efficiently inhibited CXCR4-dependent migration and in vivo it significantly reduced lung metastases and increased overall survival in B16-CXCR4 injected C57BL/6 mice. To evaluate if PL-Peptide R could also be a drug delivery system for CXCR4 expressing tumors, the PL-Peptide R was loaded with doxorubicin (DOX) (PL-Peptide R-DOX). PL-Peptide R-DOX efficiently delivered DOX to CXCR4 expressing cell lines with a consequent decrease in the DOX IC50 efficient dose. In vivo, B16-CXCR4 injected C57BL/6 mice treated with PL-Peptide R-DOX developed fewer lung metastases compared to PL-DOX treated mice. This work provides the proof-of-concept to prevent metastasis by using combined nanomedicine.

The resistance to chemotherapy and the tumor escape from host immunosurveillance are the main causes of the failure of anthracycline-based regimens in breast cancer, where an effective chemo-immunosensitizing strategy is lacking.The clinically used aminobisphosphonate zoledronic acid (ZA) reverses chemoresistance and immunoresistance in vitro. Previously we developed a nanoparticle-based zoledronic acid-containing formulation (NZ) that allowed a higher intratumor delivery of the drug compared with free ZA in vivo. We tested its efficacy in combination with doxorubicin in breast tumors refractory to chemotherapy and immune system recognition as a new combinatorial approach to produce chemo- and immunosensitization.NZ reduced the IC50 of doxorubicin in human and murine chemoresistant breast cancer cells and restored the doxorubicin efficacy against chemo-immunoresistant tumors implanted in immunocompetent mice. By reducing the metabolic flux through the mevalonate pathway, NZ lowered the activity of Ras/ERK1/2/HIF-1α axis and the expression of P-glycoprotein, decreased the glycolysis and the mitochondrial respiratory chain, induced a cytochrome c/caspase 9/caspase 3-dependent apoptosis, thus restoring the direct cytotoxic effects of doxorubicin on tumor cell. Moreover, NZ restored the doxorubicin-induced immunogenic cell death and reversed the tumor-induced immunosuppression due to the production of kynurenine, by inhibiting the STAT3/indoleamine 2,3 dioxygenase axis. These events increased the number of dendritic cells and decreased the number of immunosuppressive T-regulatory cells infiltrating the tumors.Our work proposes the use of nanoparticle encapsulating zoledronic acid as an effective tool overcoming at the same time chemoresistance and immunoresistance in breast tumors, thanks to the effects exerted on tumor cell and tumor-infiltrating immune cells.

Introduction: Nursing personnel have high risk for incidence of low back pain (LBP) followed by development of chronic pain and disability. Multiple risk factors such as patient handling, night shift work and lack of supporting work culture have been identified. In subacute LBP, high-fear avoidance is prognostic for more pain, disability and not returning to work. Lack of leisure-time physical activity predicts long-term sickness absence. The purpose of this study is to compare effectiveness of 6-month neuromuscular exercise and counselling in treating back pain in female nursing personnel with recurrent non-specific LBP pain compared with either (exercise or counselling) alone and a non-treatment control group., Methods and Analysis: The design is of a double-blinded four-arm randomised controlled trial with cost-effectiveness evaluation at 12 and 24 months. The study is conducted in 3 consecutive substudies. The main eligibility criteria are experience of LBP during the past 4 weeks with intensity of at least 2 (Numeric Rating Scale 0-10) and engagement in patient handling. Sample size was estimated for the primary outcome of pain intensity (visual analogue scale). Study measurements are outlined according to the model of International Classification of Functioning, Disability and Health, which incorporates the biopsychosocial processes assessed., Ethics and Dissemination: This study is carried out conforming to the guidelines of good scientific practice and provisions of the declaration of Helsinki. Increasing physical and mental capacity with interventions taking place immediately after working hours near the worksite may reduce development of chronic LBP and work disability in female nursing personnel with recurrent non-specific LBP., Trial Registration Number: NCT04165698.

The overexpression of ATP binding cassette (ABC) transporters makes tumor cells simultaneously resistant to several cytotoxic drugs. Impairing the energy metabolism of multidrug resistant (MDR) cells is a promising chemosensitizing strategy, but many metabolic modifiers are too toxic in vivo. We previously observed that the aminobisphosphonate zoledronic acid inhibits the activity of hypoxia inducible factor-1a (HIF-1a), a master regulator of cancer cell metabolism. Free zoledronic acid, however, reaches low intratumor concentration. We synthesized nanoparticle formulations of the aminobisphosphonate that allow a higher intratumor delivery of the drug. We investigated whether they are effective metabolic modifiers and chemosensitizing agents against human MDR cancer cells in vitro and in vivo. At not toxic dosage, nanoparticles carrying zoledronic acid chemosensitized MDR cells to a broad spectrum of cytotoxic drugs, independently of the type of ABC transporters expressed. The nanoparticles inhibited the isoprenoid synthesis and the Ras/ERK1/2-driven activation of HIF-1α, decreased the transcription and activity of glycolytic enzymes, the glucose flux through the glycolysis and tricarboxylic acid cycle, the electron flux through the mitochondrial respiratory chain, the synthesis of ATP. So doing, they lowered the ATP-dependent activity of ABC transporters, increasing the chemotherapy efficacy in vitro and in vivo. These effects were more pronounced in MDR cells than in chemosensitive ones and were due to the inhibition of farnesyl pyrophosphate synthase (FPPS), as demonstrated in FPPS-silenced tumors. Our work proposes nanoparticle formulations of zoledronic acid as the first not toxic metabolic modifiers, effective against MDR tumors.

Purpose: To investigate the prevalence of low back pain among Finnish firefighters and to examine whether sleep disturbances predict membership of low back pain trajectories., Methods: In this prospective study, 360 actively working firefighters responded to a questionnaire in 1996, 1999 and 2009. The outcome variables were radiating and local low back pain during the preceding year. Using logistic regression modeling, the likelihood of membership of pain trajectories was predicted by sleep disturbances at baseline., Results: During the 13-year follow-up, the prevalence of radiating low back pain increased from 16 to 29 % (p < 0.0001) and that of local low back pain from 28 to 40 % (p < 0.001). The following trajectories were identified: "pain free," "recovering," "new pain," "fluctuating" and "chronic." More than one-fifth of the participants belonged to the new pain trajectory as regards both pain types, 6 % of the participants belonged to the chronic radiating and 12 % to the chronic local low back pain trajectory. Those with sleep disturbances at baseline had a 2.4-fold risk (adjusted OR 2.4; 95 % CI 1.2-4.7) of belonging to the new pain or chronic radiating pain cluster compared to pain-free participants., Conclusions: This is the first prospective study to show that low back symptoms are common and persistent among firefighters and that sleep disturbances strongly predict membership of a radiating pain trajectory. Occupational health and safety personnel, as well as the firefighters themselves, should recognize sleep problems early enough in order to prevent back pain and its development into chronic pain.

Glioblastomas are highly aggressive adult brain tumors with poor clinical outcome. In the central nervous system (CNS) the blood-brain barrier (BBB) is the most important limiting factor for both development of new drugs and drug delivery. Here, we propose a new strategy to treat glioblastoma based on transferrin (Tf)-targeted self-assembled nanoparticles (NPs) incorporating zoledronic acid (ZOL) (NPs-ZOL-Tf). NPs-ZOL-Tf have been assessed on the glioblastoma cell line U373MG-LUC that showed a refractoriness in vitro to temozolomide (TMZ) and fotemustine (FTM). NPs-ZOL-Tf treatment resulted in higher in vitro cytotoxic activity than free ZOL. However, the potentiation of anti-proliferative activity of NPs-ZOL-Tf was superimposable to that one induced by NPs-ZOL (not armed with Tf). On the other hand, NPs-ZOL-Tf showed a higher antitumor efficacy if compared with that one caused by NPs-ZOL in immunosuppressed mice intramuscularly bearing U373MG-LUC xenografts, inducing a significant tumor weight inhibition (TWI). The experiments performed on mice with intracranial U373MG-LUC xenografts confirmed the efficacy of NPs-ZOL-Tf. These effects were paralleled by a higher intratumour localization of fluorescently-labeled-NPs-Tf both in intramuscular and intracranial xenografts. In conclusion, our results demonstrate that the encapsulation of ZOL increases the antitumor efficacy of this drug in glioblastoma through the acquisition of ability to cross the BBB.

Objective: To identify work ability trajectories among Finnish firefighters during a 13-year follow-up. We examined whether baseline musculoskeletal pain and depressive symptoms (DPS) predicted membership of the trajectories., Methods: We studied 411 male firefighters who responded to a questionnaire at both baseline and at least one of two follow-ups. The outcome variable was perceived work ability (0 to 10). The predictors were musculoskeletal and depressive symptoms. Covariates included age, diseases, lifestyle habits, and work-related factors., Results: One fourth of the firefighters belonged to the Diminished work ability trajectory. Musculoskeletal and depressive symptoms, lifestyle risks and diseases, and, in separate analyses, low back pain, were strong predictors of this., Conclusions: When planning preventive actions and workplace health promotion among firefighters, even one site musculoskeletal pain and mild signs of depression should be taken into account. Prevention of adverse lifestyle habits is also essential.

Multiple myeloma (MM) is a disease with an adverse outcome and new therapeutic strategies are urgently awaited. A rising body of evidence supports the notion that microRNAs (miRNAs), master regulators of eukaryotic gene expression, may exert anti-MM activity. Here, we evaluated the activity of synthetic miR-34a in MM cells. We found that transfection of miR-34a mimics in MM cells induces a significant change of gene expression with relevant effects on multiple signal transduction pathways. We detected early inactivation of pro-survival and proliferative kinases Erk-2 and Akt followed at later time points by caspase-6 and -3 activation and apoptosis induction. To improve the in vivo delivery, we encapsulated miR-34a mimics in stable nucleic acid lipid particles (SNALPs). We found that SNALPs miR-34a were highly efficient in vitro in inhibiting growth of MM cells. Then, we investigated the activity of the SNALPs miR-34a against MM xenografts in SCID mice. We observed significant tumor growth inhibition (p<0.05) which translated in mice survival benefits (p=0.0047). Analysis of miR-34a and NOTCH1 expression in tumor retrieved from animal demonstrated efficient delivery and gene modulation induced by SNALPs miR-34a in the absence of systemic toxicity. We here therefore provide evidence that SNALPs miR-34a may represent a promising tool for miRNA-therapeutics in MM.

In this work we investigated how the surface charge and the presence of polyethylene glycol (PEG) on liposome carriers affect the delivery of the encapsulated doxorubicin in P-glycoprotein (Pgp)-overexpressing cells. We found that neutral net charge was critical to favour the liposome uptake and decrease the Vmax of doxorubicin efflux. PEG-coating was necessary to increase the Km of doxorubicin for Pgp. In particular the PEGylated phospholipid present in neutral liposomes, i.e. PEGylated distearoyl-phosphatidylethanolamine (DSPE-PEG), was a Pgp allosteric inhibitor, increased doxorubicin Km and inhibited Pgp ATPase activity. Site-directed mutagenesis experiments suggested that the domain centred around glycine 185 of Pgp was necessary for these inhibitory properties of DSPE-PEG and PEGylated neutral liposomes. We conclude that both surface charge and PEGylation must be considered to optimize the doxorubicin delivery within chemoresistant cells. DSPE-PEG-enriched particles may represent promising tools for therapeutic and diagnostic applications in tissues with high levels of Pgp., From the Clinical Editor: These authors investigated how surface charge and PEGylation of liposome carriers affect the delivery of encapsulated doxorubicin to Pgp-overexpressing cells, concluding that both factors need to be considered in order to optimize doxorubicin delivery to chemoresistant cells., (© 2013.)

Objective: To investigate developmental paths in multisite musculoskeletal pain (MPS) and depressive symptoms (DPS) and the effects of job demands (JD), job resources (JR), optimism and health-related lifestyle on these paths. We expected to find four trajectories--Low Symptoms, High Pain, High Depression and High Symptoms--and hypothesised that high JDs, low JRs, low optimism and adverse lifestyle predict belonging to trajectories with high symptom levels., Design: Data on Finnish firefighters (N = 360) were collected in 1996, 1999 and 2009. The effects of JDs (mental and physical workload), JRs (supervisory relations, interpersonal relations, task resources), optimism and lifestyle (alcohol consumption, smoking, physical exercise, sleeping) on MPS and DPS were assessed. Latent class growth modelling and multinomial logistic regression were applied., Results: Three trajectories emerged: Low Symptoms; High Pain; and High Depression. In a multivariable model, high mental workload (OR 2.9, 95% CI 1.5-5.5), poor interpersonal relations (2.6, 1.4-5.0), sleeping problems (2.7, 1.4-5.2) and low optimism (2.0, 1.0-3.7) predicted belonging to High Depression. Alcohol consumption (2.4, 1.4-4.1) and sleeping problems (2.1, 1.3-3.6) were related to High Pain., Conclusions: Different developmental paths in MPS and DPS are possible. Partly different factors predict the development of pain and depressive symptoms.

Time-lapse live cell imaging is a powerful tool for studying the responses of cells to drugs. Zoledronic acid (ZOL) is the most potent aminobiphosphonate able to induce cell growth inhibition at very low concentrations. The lack of clear evidence of ZOL-induced anti-cancer effects is likely due to its unfavorable pharmacokinetic profile. The use of nanotechnology-based formulations allows overcoming these limitations in ZOL pharmaco-distribution. Recently, stealth liposomes (LIPOs) and new self-assembly PEGylated nanoparticles (NPs) encapsulating ZOL were developed. Both the delivery systems showed promising anticancer activity in vitro and in vivo. In this work, we investigated the cytostatic effect of these novel formulations (LIPOs and NPs) compared with free ZOL on 2 different prostate cancer cell lines, PC 3 and DU 145 and on prostate epithelial primary cells EPN using time lapse video-microscopy (TLVM). In PC3 cells, free ZOL showed a significant anti-proliferative effect but this effect was lower than that induced by LIPOs and NPs encapsulating ZOL; moreover, LIPO-ZOL was more potent in inducing growth inhibition than NP-ZOL. On the other hand, LIPO-ZOL slightly enhanced the free ZOL activity on growth inhibition of DU 145, while the anti-proliferative effect of NP-ZOL was not statistically relevant. These novel formulations did not induce anti-proliferative effects on EPN cells. Finally, we evaluated cytotoxic effects on DU145 where, LIPO-ZOL induced the highest cytotoxicity compared with NP-ZOL and free ZOL. In conclusion, ZOL can be transformed in a powerful anticancer agent, if administered with nanotechnology-based formulations without damaging the healthy tissues.

Objective: To investigate the change trajectories of positive and negative moods and their relationship to work ability, self-rated health, and life satisfaction in a three-wave 13-year follow-up study., Methods: The data, consisting of Finnish firefighters (n = 360), were collected via questionnaires in 1996, 1999, and 2009., Results: Four distinct mood trajectories were identified by latent class growth modeling: (1) high positive, (2) high positive but decreasing, (3) moderately positive, and (4) high negative. The trajectory groups were differentially related to well-being. Members of the high positive trajectory had better well-being than members of other latent mood trajectories., Conclusions: Different trajectories exist in positive and negative moods, and these trajectories are differentially related to well-being. Developing work environments in which a positive mood can flourish is beneficial in terms of better well-being among employees.

In the pathogenesis of neuropathic pain, the conversion of astrocytes in the reactive state and the ras-dependent Erk-mediated pathway play an important role. Zoledronic acid (ZOL) is a potent inhibitor of the latter pathway, but its activity in neurological diseases is hampered by its biodistribution that is almost exclusively limited to the bone. We have developed nanotechnological devices able to increase the accumulation of ZOL in extra bone sites. In this work, we have evaluated the effects of ZOL-encapsulating PEGylated liposomes (LipoZOL) on an animal model of neuropathic pain. We have found that 2 iv administrations (10 μg of ZOL, either as free or encapsulated into liposomes) at days 2 and 4 after the injury markedly reduced mechanical hypersensitivity at 3 and 7 days after nerve injury. On the other hand, free ZOL did not exert any significant alteration of the mechanical threshold. Immunohistochemical analysis of spinal cord revealed that GFAP-labeled astrocytes appeared hypertrophic activated cells in the ispilateral dorsal horn of spinal cord 7 days after SNI. LipoZOL significantly changed astrocyte morphology, by inducing a protective phenotype, without changing the total cell number. Moreover, the astrocytes of the spinal cord of LipoZOL-treated mice were positive for interleukin-10. Delivery of ZOL into the CNS was confirmed by biodistribution of fluorescently labeled liposomes. In particular, liposomes accumulated in the liver and kidney in both groups of normal and neuropathic animals; on the other hand, only in the case of neuropathic animals, a fluorescence increase in the brain and spinal cord occurred only in neuropathic animals at 30 min and 1 h. These data demonstrate that ZOL, only by using a delivery system able to cross the altered BBB, could be a new opportunity to treat neuropathic pain.

Occasionally firefighters need to perform very heavy bouts of work, such as smoke diving or clearing an accident site, which induce significant muscle fatigue. The time span for muscular recovery from such heavy work is not known. The purpose of this study was to evaluate firefighters' force-, neural-, metabolic-, and structural-related recovery after task-specific heavy work in the heat. Fifteen healthy firefighters (14 males and 1 female) performed a 20-min heavy work bout that simulated smoke diving and the clearance of an accident site at 35 °C. After the work, muscular recovery was evaluated by wrist flexion maximal voluntary contraction (MVC), average electromyography during MVC and during 10%MVC, rate of force production, motor response and stretch reflex responses, muscle oxygen consumption and oxygenation level, and wrist flexor muscle pennation angle. Recovery was followed for 4 h. Each of the 12 measured parameters changed significantly (p < 0.05) from those at baseline during the follow-up. Muscle oxygen consumption and the wrist flexor pennation angle remained elevated throughout the follow-up (oxygen consumption baseline, 12.9 ± 1.7 mL O2·min(-1)·(100 g)(-1); 4-h value, 17.5 ± 1.6 mL O2·min(-1)·(100 g)(-1); p < 0.05 and pennation angle baseline, 15.7 ± 0.8°; 4-h value, 17.8 ± 0.8°; p < 0.05). Muscle reoxygenation rate was elevated for up to 2 h (baseline, 2.3 ± 0.4 μmol·L(-1)·min(-1); 2-h value, 3.4 ± 0.4 μmol·L(-1)·min(-1); p < 0.05). The other 9 parameters recovered (were no longer significantly different from baseline) after 20 to 60 min. We concluded that the recovery order in main components of muscle function from fastest to slowest was force, neural, metabolic, and structural.

Purpose: To examine the associations of age, lifestyle and work-related factors, and particularly work engagement with the work ability index (WAI) and its sub-dimensions., Methods: Step-wise regression analysis with a sample of Finnish firefighters (n = 403) was used. The outcome variables were the WAI and its six sub-dimensions. The independent variables consisted of age, lifestyle variables (alcohol consumption, BMI, smoking, physical exercise, and sleep problems), working conditions (job demands, physical workload, supervisory relations, and task resources), and work engagement. The outcome variables and all the variables related to lifestyle, working conditions, and work engagement were measured in 2009. Work ability at baseline 10 years earlier was adjusted for in the models., Results: Work engagement, age, physical exercise, sleep problems, and physical workload were associated with the WAI. All independent variables, except BMI and alcohol consumption, were associated with at least one sub-dimension of the WAI after controlling the baseline WAI. Lifestyle variables, working conditions, and work engagement were more strongly related to the subjective WAI sub-dimensions than to the two more objective WAI sub-dimensions., Conclusions: Work engagement was significantly associated with work ability even after adjusting for various factors, indicating its importance in promoting work ability. Other key factors for good work ability were frequent exercise, good sleep, non-smoking, low job demands, low physical workload, and high task resources. More specifically, this study suggests that in maintaining work ability, it is valuable not only to promote lifestyle factors or working conditions, but also to enhance employees' positive state of work engagement.

Objective: To describe changes in aging firefighters' aerobic capacity at 3- and 13-year follow-ups, and to investigate the lifestyle factors predicting them. We evaluated the sufficiency of aerobic capacity for the demands of rescue diving., Methods: We studied 78 male Finnish firefighters aged 30 to 44 years at baseline. The outcome variable was aerobic capacity (L·min(-1) and mL·kg(-1)·min(-1)). The predictors were exercise, smoking, and drinking habits., Results: The average annual change (range) in absolute and relative aerobic capacity was -1.12% (-3.43 to 1.39) and -1.33% (-3.98 to 1.63). Exercising at least 4 to 5 times a week was the best protective factor, and regular smoking and more than 15 units of alcohol a week were risk factors for decline in aerobic capacity., Conclusions: To prevent the excessive decline of aerobic capacity related to work demands, we must pay particular attention to exercise regularity.

The World Trade Center catastrophe and subsequent rescue and clearance operations caused unusual respiratory tract symptoms in fire fighters and rescue workers. Persistent cough was a common symptom, being extraordinarily often associated with the gastroesophageal reflux symptom. Irritant dusts caused reactive airways dysfunction syndrome (RADS). Tracheal hyperreactivity increased with the exposure, and the risk of asthma is estimated to have increased up to 12 times higher as compared with the normal population. Investigation and treatment of exposed persons have yielded generalizable information about the reactions of the respiratory system in situations of heavy exposure.

Objective: The objective of this study was to investigate individual and work-related psychosocial factors associated with changes in the perceived physical and mental strain among fire-fighters., Methods: The 3-year follow-up study, done by a questionnaire, was based on data on 632 fire-fighters. The associations were investigated mainly by logistic regression modelling., Results: Accidents were associated with increased perceived physical as well as mental strain (OR 1.4-2.6). Unfair distribution of work tasks was associated with increased perceived physical strain (OR 8.5, CI 1.5-49.6). Frequent differences of opinion disturbing work (OR 2.7, CI 1.2-6.1) and lack of possibilities for career advancement (OR 4.6, CI = 1.0-22.5) were associated with perceived increased mental strain at work., Conclusions: The results suggest that measures to reduce the perceived physical and mental strain of fire-fighters should be multi-factorial. However, to determine the content of the measures needs further intervention studies.

ORP2 [OSBP (oxysterol-binding protein)-related protein 2] belongs to the 12-member mammalian ORP gene/protein family. We characterize in the present study the effects of inducible ORP2 overexpression on cellular cholesterol metabolism in HeLa cells and compare the results with those obtained for CHO cells (Chinese-hamster ovary cells) that express ORP2 constitutively. In both cell systems, the prominent phenotype is enhancement of [14C]cholesterol efflux to all extracellular acceptors, which results in a reduction of cellular free cholesterol. No change was observed in the plasma membrane cholesterol content or distribution between raft and non-raft domains upon ORP2 expression. However, elevated HMG-CoA (3-hydroxy-3-methylglutaryl-CoA) reductase activity and LDL (low-density lipoprotein) receptor expression, as well as enhanced transport of newly synthesized cholesterol to a cyclodextrin-accessible pool, suggest that the ORP2 expression stimulates transport of cholesterol out of the endoplasmic reticulum. In contrast with ORP2/CHO cells, the inducible ORP2/HeLa cells do not show down-regulation of cholesterol esterification, suggesting that this effect represents an adaptive response to long-term cholesterol depletion in the CHO cell model. Finally, we provide evidence that ORP2 binds PtdIns(3,4,5)P(3) and enhances endocytosis, phenomena that are probably interconnected. Our results suggest a function of ORP2 in both cholesterol trafficking and control of endocytic membrane transport.

Astrocytes secrete cholesterol in lipoprotein particles. Here we show that primary murine embryonic astrocytes secrete endogenously synthesized cholesterol but also the cholesterol precursors desmosterol and lathosterol. In astrocyte membranes, desmosterol and cholesterol were the predominant sterols. Astrocytes derived from Niemann-Pick type C lipidosis (NPC1-/-) mice displayed late endosomal cholesterol deposits, but the secretion of biosynthetic sterols from the cells was not inhibited. Both wild-type and NPC1-/- astrocytes secreted the NPC2 protein. Size-exclusion chromatography combined with electron microscopy showed that the majority of sterols were secreted separately from NPC2 in heterogeneous spherical particles with an average diameter of 20 nm. These data suggest that NPC2 and the majority of sterols secreted from astrocytes are not released together and that the secretion of neither sterols nor NPC2 requires NPC1 function. In addition, the findings reveal a complexity of sterol species in astrocytes and bring up the possibility that some of the effects assigned to astrocyte cholesterol may be attributed to its penultimate precursors.

Objective: The importance of balance abilities for firefighting and rescue work has already been recognized, but there are no valid balance tests available in the test batteries for the physical work capacity of firefighters. Moreover, few studies have examined the associations between balance and work ability in general. Valid work-related balance tests are needed for the purpose of screening in occupational health care and in rehabilitation for assessing the effects of balance training. This study aimed to investigate the predictive value of functional, postural and perceived balance in respect to work ability among firefighters at baseline and after a 3-year follow-up., Methods: The subjects were 135 male firefighters aged 33-56 years. The outcome variables were the work ability index and perceived physical work ability (PWA), determined by questionnaire in 1996 and 1999. The predictors assessed in 1996 were postural balance (tested with a force platform), functional balance (measured during walking on a wooden plank), and perceived balance abilities, enquired about through a questionnaire., Results: Most of the balance test results and the perceived balance ability were associated with the perceived PWA at baseline. The final logistic regression models showed that the best predictors of decreased work ability among firefighters after 3 years were poor-to-moderate perceived balance [odds ratios (ORs) 2.4, 95% confidence interval (CI) 0.9-6.6]; more than one error in the functional balance test (OR 3.6, 95% CI 1.0-12.7); and a high mean amplitude of postural sway with the eyes closed (OR 2.7, 95% CI 0.9-6.1)., Conclusions: The results support the work-related and predictive validity, in terms of perceived work ability, perceived balance, errors in the functional balance test and amplitude of postural sway with the eyes closed, of measuring balance among firefighters.

Introduction: Firefighters must work on roofs, in smoky places, and on slippery surfaces while using fire-protective clothing and a self-contained breathing apparatus (SCBA), together termed "fire-protective equipment" (FPE). The aim of this study was to investigate the effects of FPE on the functional and postural balance abilities of younger and older firefighters., Methods: The subjects were professional firefighters in age groups 33-38 and 43-56 yr. Postural balance was tested with a force platform, and functional balance was measured during walking on a wooden plank with and without FPE., Results: Wearing FPE significantly impaired both postural and functional balance. Postural balance with eyes closed was more negatively affected among the older subjects than the younger ones. Among the older subjects, the mean values for mediolateral velocity were 3.4 +/- 0.8 and 4.8 +/- 2.1 mm x s(-1) without and with FPE, respectively. The corresponding figures for velocity moment were 11.4 +/- 5.1 and 20.7 +/- 15.1 mm2 x s(-1). In the younger age group, the corresponding results were 3.6 +/- 1.0 and 4.1 +/- 1.4 mm x s(-1), in mediolateral velocity and 10.8 +/- 5.0 and 13.9 +/- 8.1 mm2 x s(-1) in velocity moment. SCBA was the most significant single piece of equipment to decrease performance in the functional balance test., Conclusions: These findings should be taken into consideration for preventing balance-related injuries in firefighting and rescue work, especially for older firefighters. Furthermore, balance should be considered in developing FPE and training protocols for firefighter fitness.

Previous work demonstrates that the biosynthetic precursor of cholesterol, desmosterol, is released from cells and that its efflux to high density lipoprotein or phosphatidylcholine vesicles is greater than that of newly synthesized cholesterol (Johnson, W. J., Fischer, R. T., Phillips, M. C., and Rothblat, G. H. (1995) J. Biol. Chem. 270, 25037-25046). Here we report that the release of individual precursor sterols varies with the efflux of newly synthesized zymosterol being greater than that of lathosterol and both exceeding that of newly synthesized cholesterol when using either methyl-beta-cyclodextrin or complete serum as acceptors. The transfer of newly synthesized lathosterol to methyl-beta-cyclodextrin was inhibited by actin polymerization but not by Golgi disassembly whereas that of newly synthesized cholesterol was inhibited by both conditions. Newly synthesized lathosterol associated with cellular detergent-resistant membranes more rapidly than newly synthesized cholesterol. Upon efflux to serum, newly synthesized cholesterol precursors associated with both high and low density lipoproteins. Stimulation of the formation of direct endoplasmic reticulum-plasma membrane contacts was accompanied by enhanced efflux of newly synthesized lathosterol but not of newly synthesized cholesterol to serum acceptors. The data indicate that the efflux of cholesterol precursors differs not only from that of cholesterol but also from each other, with the more polar zymosterol being more avidly effluxed. Moreover, the results suggest that the intracellular routing of cholesterol precursors differs from that of newly synthesized cholesterol and implicates a potential role for the actin cytoskeleton and endoplasmic reticulum-plasma membrane contacts in the efflux of lathosterol.

In this study, we compared the transport of newly synthesized cholesterol with that of influenza virus hemagglutinin (HA) from the endoplasmic reticulum to the plasma membrane. The arrival of cholesterol on the cell surface was monitored by cyclodextrin removal, and HA transport was monitored by surface trypsinization and endoglycosidase H digestion. We found that disassembly of the Golgi complex by brefeldin A treatment resulted in partial inhibition of cholesterol transport while completely blocking HA transport. Further, microtubule depolymerization by nocodazole inhibited cholesterol and HA transport to a similar extent. When the partitioning of cholesterol into lipid rafts was analyzed, we found that newly synthesized cholesterol began to associate with low-density detergent-resistant membranes rapidly after synthesis, before it was detectable on the cell surface, and its raft association increased further upon chasing. When cholesterol transport was blocked by using 15 degrees C incubation, the association of newly synthesized cholesterol with low-density detergent-insoluble membranes was decreased and cholesterol accumulated in a fraction with intermediate density. Our results provide evidence for the partial contribution of the Golgi complex to the transport of newly synthesized cholesterol to the cell surface and suggest that detergent-resistant membranes are involved in the process.

We have investigated whether pyrene-labelled cholesterol esters (PyrnCEs) (n indicates the number of aliphatic carbons in the pyrene-chain) can be used to observe the degradation of low-density lipoprotein (LDL)-derived cholesterol esters (CEs) in the lysosomes of living cells. To select the optimal substrates, hydrolysis of the PyrnCE species by lysosomal acid lipase (LAL) in detergent/phospholipid micelles was compared. The rate of hydrolysis varied markedly depending on the length of the pyrenyl chain. Pyr10CE was clearly the best substrate, while Pyr4CE was practically unhydrolysed. Pyr10CE and [3H]cholesteryl linoleate, the major CE species in LDL, were hydrolysed equally by LAL when incorporated together into reconstituted LDL (rLDL) particles, thus indicating that Pyr10CE is a reliable reporter of the lysosomal degradation of native CEs. When rLDL particles containing Pyr4CE or Pyr10CE were incubated with fibroblasts, the accumulation of bright intracellular vesicular fluorescence was observed with the former fluorescent derivative, but not with the latter. However, when the cells were treated with chloroquine, an inhibitor of lysosomal hydrolysis, or when cells with defective LAL were employed, Pyr10CE also accumulated in vesicular structures. HPLC analysis of cellular lipid extracts fully supported these imaging results. It is concluded that PyrnCEs can be used to observe degradation of CEs directly in living cells. This should be particularly useful when exploring the mechanisms responsible for the accumulation of lipoprotein-derived CEs in complex systems such as the arterial intima.

The effect of the physical state of low density lipoprotein (LDL) core and the selectivity of the degradation of LDL cholesterol esters (CEs) by the lysosomal acid lipase (LAL) in vitro were investigated. The physical state of LDL was modulated by varying temperature or the triglyceride content of the core. Normal LDL showed an abrupt increase of CE hydrolysis at 24 degrees C and another deviation occurred close to 36 degrees C. 1H-NMR measurements showed that these temperatures coincide with the onset and end temperatures of the LDL core lipid transition, respectively. Enrichment of LDL with triglycerides abolished the abrupt changes both in the CE hydrolysis and in the physical state of LDL lipids. These findings show that there is a correlation between the physical state of LDL lipids and the rate of LAL-mediated hydrolysis of the CEs in the particle. The relative rates of hydrolysis of different CE species were also compared. With native LDL, increasing the length of a saturated acyl chain from 14 to 20 carbons reduced the rate of degradation of CE modestly, while increasing acyl chain unsaturation increased the rate of degradation markedly. However, cholesterol oleate was hydrolyzed more slowly than cholesterol stearate. Essentially the same order of hydrolytic susceptibility was observed when the CE species were incorporated into triglyceride-enriched LDL, reconstituted high density lipoprotein particles or in detergent/phospholipid micelles. These results indicate that the selective hydrolysis of CE species in LDL is determined mainly by the ease with which the CE molecule can emerge from the surface layer reach the active site of LAL. Slower degradation of the more saturated CEs by LAL could lead, under certain conditions, to their accumulation in lysosomes and eventually, to cell death, lysis and deposition of crystalline, poorly mobilizable lipids to the arterial intima.

1. Phospholipid transfer protein (PLTP) mediates conversion of high-density lipoprotein (HDL3) to large particles, with concomitant release of apolipoprotein A-I (apoA-I). To study the mechanisms involved in this conversion, reconstituted HDL (rHDL) particles containing either fluorescent pyrenylacyl cholesterol ester (PyrCE) in their core (PyrCE-rHDL) or pyrenylacyl phosphatidylcholine (PysPC) in their surface lipid layer (PyrPC-rHDL) were prepared. Upon incubation with PLTP they behaved as native HDL3, in that their size increased considerably. 2. When PyrPC-rHDL was incubated with HDL3 in the presence of PLTP, a rapid decline of the pyrene excimer/monomer fluorescence ratio (E/M) occurred, demonstrating that PLTP induced mixing of the surface lipids of PyrPC-rHDL and HDL3. As this mixing was almost complete before any significant increase in HDL particle size was observed, it represents PLTP-mediated phospholipid transfer or exchange that is not directly coupled to the formation of large HDL particles. 3. When core-labelled PyrCE-rHDL was incubated in the presence of PLTP, a much slower, time-dependent decrease of E/M was observed, demonstrating that PLTP also promotes mixing of the core lipids. The rate and extent of mixing of core lipids correlated with the amount of PLTP added and with the increase in particle size. The enlarged particles formed could be visualized as discrete, non-aggregated particles by electron microscopy. Concomitantly with the appearance of enlarged particles, lipid-poor apoA-I molecules were released. These data, together with the fact that PLTP has been shown not to mediate transfer of cholesterol esters, strongly suggest that particle fusion rather than (net) lipid transfer or particle aggregation is responsible for the enlargement of HDL particles observed upon incubation with PLTP.4.ApoA-I rHDL, but not apoA-II rHDL, were converted into large particles, suggesting that the presence of apoA-I is required for PLTP-mediated HDL fusion. A model for PLTP-mediated enlargement of HDL particles is presented.

The job demands on physical work capacity and the frequency of the firefighting and rescue tasks were rated by 156 professional firefighters (age range, 22 to 54 years) who responded to a questionnaire. Smoke-diving requiring the use of personal protective equipment was considered to demand most aerobic power. The clearing of debris with heavy manual tools, and roof work set the highest demands on muscular performance and motor coordination, respectively. During the past 5 years, 83 to 88% of the respondents had performed these tasks on average four times a year. The rating and frequency of the tasks were not significantly affected by age. The results suggest that the job demands on physical work capacity remain the same throughout the occupational career of the firefighters.

While wearing a self-contained breathing apparatus and fire-protective clothing, 35 healthy firefighting students aged 19-27 years performed smoke-diving (entry into a smoke-filled room) during a simulated shipboard fire. The mean (+/- SD) ambient temperature inside the simulator was 119 +/- 12 degrees C, and the task lasted 17 +/- 4 min. All subjects were fit according to their maximal oxygen consumption, which was 52.4 +/- 5.2 mL/min/kg (4.08 +/- 0.45 l/min). During the smoke-diving the average heart rate was 150 +/- 13 beats/min (79 +/- 6% of maximal heart rate attained in a cycle-ergometer test), and the peak heart rate was 180 +/- 13 beats/min (95 +/- 6% of maximal heart rate). The estimated oxygen consumption was 2.4 +/- 0.5 L/min (60 +/- 12% of maximal oxygen consumption). Neither ability to tolerate stress (as determined by the instructors) nor previous experience in smoke-diving tasks seemed to influence the heart rate or estimated oxygen consumption during experiment. Smoke-diving was physically very demanding even for the young and fit subjects, showing the importance of regular evaluation of the health and physical fitness of every firefighter who has to carry out smoke-diving tasks.

Partial reactions catalyzed by a (1----3)-N-acetyl-beta-D- glucosaminyltransferase (EC2.4.1.149), known to be present in human serum, were studied by use of biantennary "backbone" saccharides of oligo-N-acetyllactosamine-type as acceptors. Incubation of the radiolabeled blood-group I-active hexasaccharide, beta-D-Galp-(1----4)-beta-D-GlcpNAc-(1----3)-[beta-D-Galp- (1----4)-beta-D-GlcpNAc-(1----6)]-beta-D-Galp-(1----4)-D-GlcNAc (1) and UDP-GlcNAc with serum gave first a transient 1:1 mixture of two isomeric heptasaccharides, beta-D-GlcpNAc-(1----3)-beta-D-Galp-(1----4)-beta-D- GlcpNAc-(1----3)-[beta-D-Galp-(1----4)-beta-D-GlcpNAc-(1----6)]-beta-D- Galp-(1----4)-D-GlcNAc (2) and beta-D-Galp-(1----4)-beta-D-GlcpNAc-(1----3)-[beta-D-GlcpNAc-(1----3)- beta-D-Galp-(1----4)-beta-D-GlcpNAc-(1----6)]-beta-D-Galp-(1----4)-D-Glc NAc (3), showing that both branches of 1 react equally well. The two heptasaccharides reacted further in the incubation mixture to form the radiolabeled octasaccharide, beta-D-GlcpNAc-(1----3)-beta-D-Galp-(1----4)-beta-D-GlcpNAc-(1----3)-[be ta-D- GlcpNAc-(1----3)-beta-D-Galp-(1----4)-beta-D-GlcpNAc-(1----6)]-beta-D-Ga lp- (1----4)-D-GlcNAc (4); during this second reaction, the composition of the heptasaccharide mixture remained unchanged, indicating that 2 and 3 reacted at approximately equal rates. The heptasaccharides 2 and 3 could not be separated from each other, but they could be detected, identified, and quantitatively determined by stepwise enzymic degradations. Partial (1----3)-N-acetyl-beta-D-glucosaminylation reactions, carried out with another acceptor, the branched pentasaccharide, beta-D-Galp-(1----4)-beta-D-GlcpNAc-(1----3)-[beta-D-Galp-(1----4)-beta- D- GlcpNAc-(1----6)]-beta-D-Gal (11), revealed that it reacted also equally well at both branches.(ABSTRACT TRUNCATED AT 400 WORDS)

The Semliki Forest virus directs the synthesis of three virus-specific transmembrane proteins p62, 6K, and E1, which all are made in equimolar amounts from a polyprotein precursor molecule. The p62 and E1 spike proteins form heterodimeric complexes in the endoplasmic reticulum before being transported to the cell surface where virus budding occurs. In this study we show that the 6K protein becomes associated to the p62E1 complex in the endoplasmic reticulum and transported with the complex to the cell surface. During virus budding, E1 and p62 (which has matured into the E2 protein) are incorporated into new virions whereas the 6K is mostly excluded. Virus particles released from infected BHK cells contain only about 3% of 6K in their membrane as compared to the spike protein content. The relevance of these findings for the mechanism of SFV assembly is discussed.

Incubation of UDP-GlcNAc and radiolabeled GlcNAc beta 1-3Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4GlcNAc (1) with human serum resulted in the formation of the branched hexasaccharide GlcNAc beta 1-3Gal beta 1-4GlcNAc beta 1-3(GlcNAc beta 1-6)Gal beta 1-4GlcNAc (2) in yields of up to 22.2%. The novel reaction represents midchain branching of the linear acceptor; the previously known branching reactions of oligo-(N-acetyllactosaminoglycans) involve the nonreducing end of the growing saccharide chains. The structure of 2 was established by use of appropriate isotopic isomers of it for degradative experiments. The hexasaccharide 2 was cleaved by an exhaustive treatment with jack bean beta-N-acetylhexosaminidase, liberating two GlcNAc units and the tetrasaccharide Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4GlcNAc (3). Endo-beta-galactosidase from Bacteroides fragilis cleaved 2 at one site only, yielding the disaccharide GlcNAc beta 1-3Gal (4) and the branched tetrasaccharide GlcNAc beta 1-3(GlcNAc beta 1-6)Gal beta 1-4GlcNAc (5). The structure of 5 was established by partial acid hydrolysis and subsequent identification of the disaccharide GlcNAc beta 1-6Gal (6), together with the trisaccharides GlcNAc beta 1-6Gal beta 1-4GlcNAc (7) and GlcNAc beta 1-3(GlcNAc beta 1-6)Gal (8) among the cleavage products. Galactosylation of 2 with bovine milk beta 1,4-galactosyltransferase and UDP-[6-3H]Gal gave the octasaccharide [6-3H]Gal beta 1-4GlcNAc beta 1-3 Gal beta 1-4GlcNAc beta 1-3([6-3H]-Gal beta 1-4GlcNAc beta 1-6)[U-14C] Gal beta 1-4GlcNAc (17), which could be cleaved with endo-beta-galactosidase into the trisaccharide [6-3H]Gal beta 1-4GlcNAc beta 1-3Gal (18) and the branched pentasaccharide GlcNAc beta 1-3-([6-3H]Gal beta 1-4GlcNAc beta 1-6) [U-14C]Gal beta 1-4GlcNAc (19). Partial hydrolysis of 2 with jack-bean beta-N-acetylhexosaminidase gave the linear pentasaccharide 1 and the branched pentasaccharide Gal beta 1-4GlcNAc beta 1-3(GlcNAc beta 1-6)Gal beta 1-4GlcNAc (20). The serum beta 1,6-GlcNAc transferase catalyzed also the formation of GlcNAc beta 1-3Gal beta 1-4GlcNAc beta 1-3(GlcNAc beta 1-6)Gal beta 1-4Glc (11) from UDP-GlcNAc and GlcNAc beta 1-3Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc (10). The pentasaccharide Gal alpha 1-3Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4GlcNAc (16), too, served as an acceptor for the enzyme.(ABSTRACT TRUNCATED AT 400 WORDS)