LincRNA-ROR induces epithelial-to-mesenchymal transition and contributes to breast cancer tumorigenesis and metastasis

LncRNAs have critical roles in various biological processes ranging from embryonic development to human diseases, including cancer progression, although their detailed mechanistic functions remain illusive. The lncRNA linc-ROR has been shown to contribute to the maintenance of induced pluripotent stem cells and embryonic stem cells. In this study, we discovered that linc-ROR was upregulated in breast tumor samples, and ectopic overexpression of linc-ROR in immortalized human mammary epithelial cells induced an epithelial-to-mesenchymal transition (EMT) program. Moreover, we showed that linc-ROR enhanced breast cancer cell migration and invasion, which was accompanied by generation of stem cell properties. Contrarily, silencing of linc-ROR repressed breast tumor growth and lung metastasis in vivo. Mechanistically, our data revealed that linc-ROR was associated with miRNPs and functioned as a competing endogenous RNA to mi-205. Specifically, linc-ROR prevented the degradation of mir-205 target genes, including the EMT inducer ZEB2. Thus our results indicate that linc-ROR functions as an important regulator of EMT and can promote breast cancer progression and metastasis through regulation of miRNAs. Potentially, the findings of this study implicate the relevance of linc-ROR as a possible therapeutic target for aggressive and metastatic breast cancers.

Inhibition enhancer of zeste homologue 2 promotes senescence and apoptosis induced by doxorubicin in p53 mutant gastric cancer cells

OBJECTIVES

Enhancer of zeste homologue 2 (EZH2) is crucially involved in epigenetic silencing by acting as a histone methyltransferase. Although EZH2 is overexpressed in many cancers and is involved in malignant cell proliferation and invasion, the role of EZH2 in senescence induced by DNA damage has up to now remained largely unknown. In this study, we sought to explore the outcome of EZH2 depletion along with exposure of doxorubicin (DOX), and related mechanisms, in gastric cancer cells.

MATERIALS AND METHODS

Here, senescence induced by DNA damage was achieved in gastric cancer cells by DOX treatment. EZH2 was downregulated by transfection with siRNA or treated with (-)-epigallocatechin-3-gallate, a targeted inhibitor. Senescence-associated β galactosidase (SA-β-gal) and formation of senescence-associated heterochromatin foci were used to identify cell senescence. To investigate effects of EZH2 depletion on the cell cycle, apoptosis and proliferation, flow cytometry and MTT analysis were employed. Changes in p53-p21 axis activation were detected by Western blotting.

RESULTS

We found that cell proliferative arrest caused by DOX could be promoted by EZH2 depletion. Mechanistically, EZH2 depletion not only worked in coordination with DNA damage during the progression of cell senescence but also promoted apoptosis in p53 mutant cells. However, it had no cooperative relationship with DOX in p53 wild-type cells.

CONCLUSIONS

These data help unravel a crucial role for EZH2 in senescence and apoptosis in gastric cancer cells and that p53 genomic status was associated with different cell responses to EZH2 silencing.

Mitochondrial bioenergetic deficits in the hippocampi of rats with chronic ischemia-induced vascular dementia

Vascular dementia (VD), defined as a loss of memory and cognitive function resulting from vascular lesions in the brain, is the second-most-common cause of dementia in the elderly, after Alzheimer's disease. In recent years, research has focused on the pathogenesis of VD, and mitochondrial bioenergetic deficits have been suggested to contribute to VD onset. To further investigate the role of mitochondria in VD, we used a rat model of VD, which involved permanent bilateral occlusion of the common carotid arteries (with a 1-week interval between artery occlusion to avoid an abrupt reduction in cerebral blood flow) leading to chronic cerebral hypoperfusion. Prior to occlusion, male Wistar rats underwent 7 days of Morris water maze training. Only animals that could swim and passed the Morris water maze test were chosen for the study. After 5 days of Morris water maze training, mitochondria from the hippocampi of rats, which were randomly selected from animals that could complete the Morris water maze test, were isolated for functional assessment. Mitochondria isolated from the hippocampi of rats from the ischemia group had decreased pyruvate dehydrogenase protein levels, and increased oxidative stress, as manifested by increased hydrogen peroxide production. The ischemia group mitochondria also exhibited decreased respiration coupled to decreased expression and activity of the electron transport chain complex IV (cytochrome c oxidase). These results indicate that the mitochondrial oxidative metabolism is inhibited in the hippocampi of rats following chronic ischemia-induced VD. As the mitochondrial oxidative metabolism deficits, namely mitochondrial bioenergetic deficits directly affect the functions of neurons, it may contribute to VD onset.

Apparent diffusion coefficients of normal uterus in premenopausal women with 3 T MRI

AIM

To investigate the apparent diffusion coefficient (ADC) values of the normal uterine cervical zonal structures (cervical epithelium, the junctional zone, and myometrium) during different phases of the menstrual cycle among premenopausal women in different age groups.

MATERIALS AND METHODS

Seventy healthy women, who were divided into three age groups (group A, 24 women in their twenties; group B, 23 women in their thirties; group C, 23 women in their forties), underwent 3 T magnetic resonance imaging (MRI) with T2-weighted and diffusion-weighted imaging (DWI) during the mid-proliferative and the mid-secretory phases.

RESULTS

The ADC values of each cervical zonal structure were significantly different from one another (p < 0.001). The ADC values of the epithelium and junctional zones were both lower during the mid-secretory phase than those during the mid-proliferative phase in each age group (p < 0.05). There were no significant differences in the ADC values of any of the cervical zones among the three age groups for a given phase (p > 0.05).

CONCLUSION

ADC values of normal cervical epithelium and the junctional zone change with different phases of the menstrual cycle, which should be taken into consideration when early cervical disease is detected, when monitoring treatment response, and differentiating early tumour recurrence.

Development and application of a loop-mediated isothermal amplification assay for rapid detection of Borrelia burgdorferi s. l. in ticks

A loop-mediated isothermal amplification (LAMP) assay was developed to detect Borrelia burgdorferi s. l. in ticks, which is a pathogen that causes Lyme disease. Cross-reactions with Chlamydia psittaci, Mycoplasma mycoides subsp. capri and some tick-borne pathogens were excluded. Analytical sensitivity of LAMP showed its detection limit was from 0.02 to 0.2 pg of DNA in detection of the reference samples at 65°C for 40 min. The performance of LAMP was assessed by testing 110 samples from susceptible tick species and comparing the results with conventional and nested PCR tests previously described. The results demonstrated that LAMP was significantly more sensitive than the conventional PCR (32.7% versus 15.5%, P < 0.05) and slightly more sensitive, although not significantly so, than nested PCR (32.7% versus 26.4%, P > 0.05). The assay was used to analyse a total of 1052 ticks collected from eight provinces in China. The results showed that the infection rates of B. burgdorferi s. l. varied from 12.5% to 88.9% across the different geographical sites. Selected positive samples were subjected to sequencing and sequence analysis for conformation of the accuracy of the assay. Here we report a highly sensitive, specific and easy diagnostic assay based on LAMP technology. These data indicate that LAMP is a useful approach for detecting B. burgdorferi s. l. in field-collected ticks and has the potential as an alternative tool for the ecological and epidemiological surveillance of Lyme disease.

Simultaneous detection of piroplasma infections in field Haemaphysalis qinghaiensis ticks by reverse line blotting

Piroplasmosis is caused by tick-borne haemoprotozoan parasites in the genera of Theileria and Babesia, in which numbers of agents are highly pathogenic for cattle, sheep and goats. We developed a reverse line blot (RLB) assay for detection and differentiation of four different parasites, in which 18S ribosomal RNA gene sequence was amplified with a set of universal primers specific for all members in the genera of Theileria and Babesia; and the probes were designed on the basis of hypervariable region 4 (V4 region) of 18S rRNA gene. Three Theileria and one Babesia can be detected simultaneously on this system and it was sensitive to detect a parasitemia level between 10(-5) and 10(-8)%. A total of 149 Haemaphysalis qinghaiensis ticks collected from Lintan County of Gannan Tibetan Autonomous Region was tested by RLB. Among these, 136 tick samples were also tested by a nested PCR assay developed previously. After comparison of these results, it showed that more T. luwenshuni was detected in RLB assay, while more T. uilenbergi was detected in H. qinghaiensis ticks by nested PCR. The RLB has shown capability for simultaneous detection of four species of piroplasm in H. qinghaiensis ticks, indicating its usefulness for epidemiological studies of piroplasmosis.

A facile preparation of novel multifunctional vectors by non-covalent bonds for co-delivery of doxorubicin and gene

In this study, novel multifunctional ternary complexes of biotinylated transferrin-avidin-biotin-poly(ethylene glycol)-poly(L-glutamate acid)/poly(2-(2-aminoethylamino) ethyl methacrylate)/doxorubicin-poly(L-aspartic acid)/pDNA (TAB/PIC-D/pDNA complexes) were prepared based on polyion complex micelles (PIC) and the avidin-biotin system, which aimed to target co-delivery of anti-cancer doxorubicin and gene. Cytotoxicity studies revealed that PIC-D could have anti-tumor effect on HeLa cells and HepG2 cells; TAB coating could increase the biocompatibility of PIC-D/pDNA complexes and the targeting delivery efficiency of doxorubicin. TAB/PIC-D/pDNA complexes possessed higher transfection efficiency than the unmodified complexes in serum, and transferrin could enhance luciferase expression in HeLa cells and HepG2 cells. Furthermore, confocal laser scanning microscopy showed that doxorubicin and gene could be delivered into HepG2 cells simultaneously by TAB/PIC-D/pDNA complexes. The formation of the ternary complexes provides a facile approach to constructing a multifunctional delivery system for targeted co-delivery of anticancer drugs and gene.

Feasibility and safety of stenting for symptomatic carotid arterial dissection

OBJECTIVE

To determine the procedural feasibility and safety of carotid angioplasty and stent placement of carotid artery dissection (CAD) patients who had failed antithrombotic therapy in acute dissection.

METHODS

A series of 33 consecutive patients (mean age, 40.21 years; 29 men and 4 women) who underwent angioplasty and stent placement for symptomatic carotid artery dissection (sCAD) from May 2005 to December 2010 in the Nanjing Stroke Registry Program (NSRP) was retrospectively reviewed. All the included patients had been diagnosed definitively based on catheter angiography, and had failed to respond to medical therapy during the course of initial hospital admission. The baseline and followed up data of these patients were collected and analyzed.

RESULTS

Of all the 33 included patients, 32 patients had achieved technical success without any intraoperative complications. Two patients manifested ipsilateral Horner sign on the next day after stenting, and one of them suffered from recurrence of transient ischaemic attack (TIA) during the course of follow up, but completely remission via antithrombotic therapy.

CONCLUSION

Endovascular stenting is a feasible and safe therapeutic strategy of CAD patients who have failed medical therapy.

Karyotypic Variation within Clonal Lineages of the Rice Blast Fungus, Magnaporthe grisea

We have analyzed the karyotype of the rice blast fungus, Magnaporthe grisea, by using pulsed-filed gel electrophoresis. We tested whether the electrophoretic karyotype of an isolate was related to its pathotype, as determined by infection assays, or its genetic lineage, as determined by DNA fingerprinting. Highly reproducible electrophoretic karyotypes were obtained for a collection of U.S. and Chinese isolates representing a diverse collection of pathotypes and genetic lineages. Chromosomes ranged in size from 3 to 10 Mb. Although chromosome number was largely invariant, chromosome length polymorphisms were frequent. Minichromosomes were also found, although their presence was not ubiquitous. They ranged in number from 1 to 3 and in size from 470 kb to 2.2 Mb. Karyotypes were sufficiently variable as to obscure the obvious relatedness of isolates on the basis of pathogenicity assays or genetic lineage analysis by DNA fingerprinting. We documented that the electrophoretic karyotype of an isolate can change after prolonged serial transfer in culture and that this change did not alter the isolate's pathotype. The mechanisms bringing about karyotype variability involve deletions, translocations, and more complex rearrangements. We conclude that karyotypic variability in the rice blast fungus is a reflection of the lack of sexuality in wild populations which leads to the maintenance of neutral genomic rearrangements in clones of the fungus.

Association between indoor exposure to semi-volatile organic compounds and building-related symptoms among the occupants of residential dwellings

The aim of this study was to evaluate the levels of semi-volatile compounds (SVOCs) in residential detached houses in Sapporo, Japan, and whether exposure to these SVOCs was associated with the development of building-related symptoms named 'sick house syndrome' (SHS). The definition of SHS is fundamentally the same as that of the sick building syndrome (SBS). The presence of symptoms of SHS was evaluated using a validated self-administered questionnaire. Surveys and samplings of air and house dust in 41 dwellings were performed from October 2006 to January 2007, and 134 occupants responded to questionnaires. Samples were analyzed to quantify the concentrations of eight plasticizers, eleven phosphate triester flame retardants, two alkyl phenols used as anti-oxidants, and one organochlorine synergist called s-421, by gas chromatography-mass spectrometry and gas chromatography-flame photometry. The compounds frequently detected were di-n-butylphthalate, di(2-ethylhexyl)phthalate (DEHP), and dibutylhydroxytoluene in air, and DEHP and tris(2-butoxyethyl)phosphate (TBEP) in dust. Tributylphosphate was strongly and directly associated with mucosal symptoms of SHS; s-421 was also directly associated with mucosal symptoms of SHS. On the contrary, some chemicals such as diethylphthalate and TBEP were inversely associated with SHS. In future studies, we plan to assess these associations in a larger population.

PRACTICAL IMPLICATIONS

This study suggests that it may be possible to reduce building-related symptoms by altering exposure to certain SVOCs, such as tributylphosphate commonly found in ceiling and wall coverings and s-421 used as a synergist for pyrethroids. The association between SHS and s-421 suggested that use of pyrethroid insecticides could elicit symptoms of SHS. However, further studies are necessary to test the associations observed in the present study and to examine whether the SVOCs associated with symptoms are causative agents or simply surrogates for some other factor that is causing the symptoms.

Differential effect of specific gr/gr deletion subtypes on spermatogenesis in the Chinese Han population

As a common variation in the azoospermia factor c (AZFc) region of Y chromosome, the gr/gr deletion is regarded as a significant risk factor for spermatogenic impairment, whereas the association of the deletion's phenotypic expression with Y-chromosomal background is still a subject of debate. To further investigate the contribution of the deletion to spermatogenic impairment in different Y-chromosomal haplogroups, the partial AZFc deletion was detected with AZFc-specific sequence tagged sites, gene dosage and gene copy analyses of deleted in azoospermia (DAZ), chromodomain Y1 (CDY1) and basic protein Y2 (BPY2) in 1426 azoo/oligozoospermic and 672 normozoospermic men from a Chinese population. The haplogrouping was performed in 231 deletion carriers with 12 polymorphic loci of Y chromosome. As a result, five gr/gr rearrangement types in eight Y haplogroups were observed, in which the simple gr/gr deletion was the most common type, and its frequency was significantly higher in men with azoo/oligozoospermia relative to normozoospermia. Also the distribution of gr/gr-rearranged Y haplogroups was significantly different between the two groups, in which gr/gr-deleted haplogroups C and DE were more common in men with azoo/oligozoospermia. In the 6 gr/gr copy deletion haplotypes, the frequencies of DAZ1/DAZ2+CDY1a or CDY1b deletion were significantly higher in men with azoo/oligozoospermia, while all DAZ3/DAZ4+CDY1b+BPY2.2 or 2.3 deletions were found only in haplogroup Q1 without any distribution difference between the azoo/oligozoospermic and normozoospermic groups. This study provided further evidence for the existence of multiple subtypes of gr/gr deletion and indicates that gr/gr-DAZ1/DAZ2 deletion is a significant risk factor. However, the association of the phenotypic variation of gr/gr deletion with Y-chromosomal haplogroups is not definite yet, because of the limited amounts of the deletions observed in each of the haplogroups and the lack of the quantitative trait analyses such as sperm density analysis. The fact that a common gr/gr copy deletion haplotype was found exclusively in the Y hgr Q1, without pathogenic consequences, implies the importance of haplogrouping and of copy deletion typing prior to genetic counselling of deletion carriers of Chinese descent.

First molecular detection of group A rotaviruses in drinking water sources in Beijing, China

The most prevalent group A rotavirus found in the diarrheic children was also determined in drinking water sources including raw water, treated water and tap water in Beijing, and then the possible contamination contributions to tap water for human consumption were discussed in this study. A total of 26 raw water samples, 77 treated water samples and 143 tap water samples in Beijing were collected for analysis of group A rotavirus from April 2006 to August 2007. According to the results, it was shown that group A rotaviruses occurred in 9 raw water samples (34.6%), 9 treated water samples (11.7%) and 32 tap water samples (22.4%) during the sampling period, and low disinfectant residuals or a vulnerability of the distribution system to pressure transients, in addition to raw water, may account for the group A rotaviruses contamination to tap water. The rotavirus contamination observed in this study may highlight a potential public health risk and illustrate the importance of including routine virological analysis of drinking water supplies during winter time in Beijing.

Low-dose oral sirolimus reduces atherogenesis, vascular inflammation and modulates plaque composition in mice lacking the LDL receptor

BACKGROUND AND PURPOSE

Chronic proliferative responses of different vascular cell types have been involved in the pathogenesis of atherosclerosis. However, their functional role remains to be established. Sirolimus reduces neointimal proliferation after balloon angioplasty and chronic graft vessel disease. These studies were undertaken to investigate the effects of this anti-proliferative drug on atherogenesis.

EXPERIMENTAL APPROACH

Low-density lipoprotein receptor-deficient (LDL r-KO) mice on a cholesterol-rich diet were randomized to receive placebo or sirolimus (0.1; 0.3; or 1 mg.kg(-1)) in their diet for 8 or 16 weeks.

RESULTS

In both studies, plasma levels of the drug increased in a dose-dependent fashion, animals gained weight normally and, among groups, plasma lipids levels did not differ significantly. Compared with placebo, plasma levels of interleukin-6, monocyte chemoattractant protein-1, interferon gamma, tumour necrosis factor alpha and CD40, and their mRNA levels in aortic tissue were significantly reduced in sirolimus-treated mice. This effect resulted in a significant and dose-dependent reduction in atherosclerotic lesions, in both the root and aortic tree. Also these lesions contained less monocyte/macrophages and smooth muscle cells, but more collagen.

CONCLUSIONS AND IMPLICATIONS

The present results demonstrated that at low doses, sirolimus was an effective and safe anti-atherogenic agent in the LDL r-KO mice. It attenuated the progression of atherosclerosis and modulated the plaque phenotype by reducing the pro-inflammatory vascular responses typical of the disease.

Maghemite nanoparticles and their protamine derivatives: cellular internalization and effects on cell-cycle progress

Dimercaptosuccinic acid-coated maghemite nanoparticles and their protamine derivatives were prepared. TEM revealed that the average size of nanoparticles is 10 nm and derivatives with larger size consist of several original nanoparticles. The cellular uptake of nanoparticles and derivatives by human hepatoma cells, and their effects on cell viability and cell-cycle were detected. Results showed that the internalization of nanoparticles into cells was very limited, while derivatives could be internalized into cells with high efficiency. Nanoparticles didn't display significant cytotoxicity at a wide range of concentrations (0.3-2.4 mg/ml), whereas derivatives had a narrow range of non-toxicity concentrations (0.3-0.6 mg/ml). Both nanoparticles and derivatives could affect cell-cycle progress and the mechanisms underlying were discussed.

Detection and differentiation of Theileria luwenshuni and T. uilenbergi infection in small ruminants by PCR

Theileria luwenshuni and T. uilenbergi are newly identified Theileria species highly pathogenic for sheep and goats in China. As they are morphologically indistinguishable and poorly characterized, there is no easily applicable method available to differentiate between these species. In the present study, PCR assays are described for the differentiation and detection of T. luwenshuni and T. uilenbergi using species-specific primers, which were designed based on the hypervariable region of the small subunit ribosomal RNA gene sequences. By testing 100 field blood samples of sheep collected from five geographically different regions where the Theileria species were described to be prevalent, the PCR assays not only detected infected samples but also identified mixed infection. This suggests that these PCR assays are useful tools for the detection of and differentiation between T. luwenshuni and T. uilenbergi.

Effects of maize grain and lucerne particle size on ruminal fermentation, digestibility and performance of cows in midlactation

This study evaluated the effects of, and interactions between, maize grain particle size (MPS) and lucerne particle size (LPS) on dry matter intake, milk production, milk composition, ruminal fermentation, microbial yield, chewing activity and nutrient digestibility in midlactation cows. Four multiparous Holstein cows with ruminal cannulas were assigned randomly to a 4 x 4 Latin square design, averaged 595 kg (SD = 52) of body weight and 121 days in milk (SD = 21) at the start of the experiment. Experimental periods were 21 days in length (14 days of treatment adaptation and 7 days of data collection). All diets were fed as total mixed ration and were formulated to meet or exceed the requirements of a 600 kg multiparous cow producing 20 kg milk/day with 4.0% fat. The ratio of concentrate to forage was 39:61 (dry matter basis). Treatments were arranged in a 2 x 2 factorial design; two levels of LPS (2.54 and 6.22 mm) were combined with concentrates based on either ground maize grain (711 mum) or cracked maize grain (1755 mum). Maize grain and LPS did not affect milk production and milk fat percentage. Milk protein percentage increased when MPS was decreased (p = 0.04). Milk urea nitrogen was lower for cows fed ground maize grain compared with cracked maize grain (118-134 mg/l, p = 0.05). Estimated microbial N supply increased 41.9 g/day for ground maize grain compared with cracked maize grain. Cows fed long lucerne (LL) hay spent more time ruminating compared with cows fed short lucerne (SL) hay ranging from 293 to 336 min/day (p < 0.001). Total time spent chewing by cows increased from 505 to 574 min/day (p = 0.002) for SL and LL respectively. Based on the results from this study, midlactation cows can be fed diets that contain ground maize grain and SL hay without leading to negative effects on ruminal pH and nutrient digestibility.

Influence of pH of TSI medium on the detection of hydrogen sulfide production by Campylobacter hyointestinalis

AIMS

To examine the influence of pH of triple sugar iron (TSI) agar medium on the detection of hydrogen sulfide (H(2)S) production in Campylobacter hyointestinalis ssp. hyointestinalis (CHH).

METHODS AND RESULTS

TSI medium was adjusted by the addition in HCl or NaOH to cover a pH 6.0-9.0. One loopful of bacterial growth of CHH strain ATCC 35217 was inoculated into each different pH medium, and incubated at 37 degrees C under micro-aerobic conditions. The H(2)S production was not detectable even after incubation for 72 h in acidic medium pH; however, TSI with alkaline pH (8.0-9.0) allowed detection as early as 3 h of incubation. A total of 20 CHH strains from various animal sources were examined for the detection of H(2)S production in TSI medium with pH 9.0. The H(2)S was detected in all the strains examined within 12 h, and the judgment was unambiguous.

CONCLUSION

The results showed that the detection of H(2)S production by CHH was influenced by medium pH, and TSI with alkaline condition is highly sensitive.

SIGNIFICANCE AND IMPACT OF THE STUDY

The findings of the present study suggest that TSI medium with alkaline pH contributes to fast detection and led to unambiguous judgment of H(2)S production by CHH.

Clinical experience with a chronic pain management programme in Hong Kong Chinese patients

OBJECTIVE

To describe experience with a chronic pain management programme in Hong Kong Chinese patients.

DESIGN

Prospective study.

SETTING

Regional hospital, Hong Kong.

PARTICIPANTS

Patients with chronic pain who participated in the first six Comprehensive Out-patient Pain Engagement programmes between 2002 and 2005.

INTERVENTION

Comprehensive Out-patient Pain Engagement is a 14-day structured, multidisciplinary out-patient programme conducted over 6 weeks. It includes pain education, cognitive re-conceptualisation, training in communication skills and coping strategies, graded physical exercises and functional activities training. It aims to improve patient function and quality of life, despite persistent pain.

MAIN OUTCOME MEASURES

Changes in scores from baseline values after joining the programme, with respect to several assessment tools. These included the following: visual analogue pain scale, Pain Catastrophizing Scale, Patient Self-efficacy Questionnaire, Canadian Occupational Performance Measure, Medical Outcome Survey-Short Form 36 Questionnaire, and duration of physical tolerances, medication utilisation, and work status records.

RESULTS

Forty-five patients were available for analysis. After the Comprehensive Out-patient Pain Engagement programme, improvements in Medical Outcome Survey-Short Form 36 Questionnaire (role physical and vitality), Pain Catastrophizing Scale, Patient Self-efficacy Questionnaire, and Canadian Occupational Performance Measure were demonstrated (P<0.05). The duration of standing and sitting tolerances increased (P<0.05). An improvement in employment rate was also evident (P=0.01).

CONCLUSION

The initial results of our management programme in Chinese patients with chronic pain are encouraging. This type of programme should be promoted more widely in this group of patients, as it appears to improve physical function, psychological well-being, and productivity.