Enablers and barriers to mental health initiatives in construction SMEs.

BACKGROUND: Mental ill-health is prevalent in the construction industry, and workers in small- to medium-sized enterprises (SMEs) are at high risk. Knowledge about the implementation of mental health initiatives in construction SMEs is limited. AIMS: To explore enablers and barriers to implementing mental health initiatives within UK SME construction firms from the perspective of the business owners, directors and managers with responsibilities for workplace mental health. METHODS: Qualitative study involving semi-structured interviews conducted with company owners/managers with responsibilities for workforce mental health. Participants were sampled from construction SMEs in the UK. RESULTS: Eleven construction professionals were interviewed (10 men, 1 woman; aged 34-55 years, M = 40.6) representing UK SME construction firms that were micro (<10 employees, n = 8), small (<50 employees, n = 1) and medium (<250 employees, n = 2) sized organizations. Reflexive thematic analysis generated four themes: (i) traditional views and macho culture, identified as barriers to implementation; (ii) mental health awareness, knowledge and education; (iii) valuing good mental health and (iv) a reactive or proactive approach to mental health, which all served as both enablers and barriers depending on perspective and context. CONCLUSIONS: This study sheds light on an under-researched but high-risk category of workers experiencing poor mental health. We provide recommendations for policy and practice with a 'call to action' for SME owners, industry and policymakers to embark on workplace mental health implementation projects in SME settings.

Development of a selective androgen receptor modulator for transdermal use in hypogonadal patients.

We have identified a non-steroidal selective androgen receptor modulator (SARM), termed LY305, that is bioavailable through a transdermal route of administration while highly cleared via hepatic metabolism to limit parent compound exposure in the liver. Selection of this compound and its transdermal formulation was based on the optimization of skin absorption properties using both in vitro and in vivo skin models that supported PBPK modeling for human PK predictions. This molecule is an agonist in perineal muscle while being a weak partial agonist in the androgenic tissues such as prostate. When LY305 was tested in animal models of skeletal atrophy it restored the skeletal muscle mass through accelerated repair. In a bone fracture model, LY305 remained osteoprotective in the regenerating tissue and void of deleterious effects. Finally, in a small cohort of healthy volunteers, we assessed the safety and tolerability of LY305 when administered transdermally. LY305 showed a dose-dependent increase in serum exposure and was well tolerated with minimal adverse effects. Notably, there were no statistically significant changes to hematocrit or HDL after 4-week treatment period. Collectively, LY305 represents a first of its kind de novo development of a non-steroidal transdermal SARM with unique properties which could find clinical utility in hypogonadal men.

The nongenotropic synthetic ligand 4-estren-3alpha17beta-diol is a high-affinity genotropic androgen receptor agonist.

The nongenotropic ligand estren (Science 298:843-846, 2002) was evaluated for its transcriptional activity mediated by the human androgen receptor (AR). Our results show that estren can bind, translocate, transactivate, and regulate two known target genes of AR in androgen-responsive cell lines. Estren binds recombinant AR with 10-fold higher affinity than either estrogen receptor (ER)-alpha or ERbeta. Estren-bound AR can translocate AR to the nucleus and stimulate the androgen response element-luciferase reporter activity with an efficacy similar to that of androgen. Estren also increased the expression of prostate-specific antigen (PSA) in a dose-dependent manner in human LnCaP cells. Using chromatin immunoprecipitation analysis, we show that the estren-bound AR coimmunoprecipitates with a region of the PSA gene promoter. Therefore, cotreatment with an AR antagonist, bicalutamide, blocked the estren-induced increase in PSA expression. In contrast, phosphoinositol 3-kinase inhibitor wortmannin, or extracellular signal-regulated kinase inhibitor 1,4-diamino-2,3-dicyano-1,4-bis(2-aminophynyltio)butadiene (U0126), and ER antagonist ICI-182780 failed to block the effects of estren. In vivo analysis of estren's action on male-orchidectomized ICR mice revealed estren's AR agonist actions on the levator ani and seminal vesicle target tissues. Taken together, our results reveal the hitherto unidentified genotropic action of estren mediated by AR in androgen-responsive cells and tissues.

IL-10 receptor dysfunction in macrophages during chronic inflammation.

The immunosuppressive activity of interleukin-10 (IL-10) makes this cytokine a potentially important clinical tool to reduce inflammatory responses in various diseases. Its efficacy as a therapeutic modality is dependent on the responsiveness of immune cells. We report that macrophages from mice chronically infected with the LP-BM5 retrovirus had a reduced capacity to respond to IL-10 in vitro. The ability of IL-10 to inhibit lipopolysaccharide-induced production of tumor necrosis factor (TNF) alpha and IL-6 was significantly reduced in both alveolar and peritoneal macrophages from infected versus uninfected mice. IL-10 hyporesponsiveness was not related to direct infection by the retrovirus, because bone marrow-derived macrophages infected in vitro with LP-BM5 were as responsive to IL-10 as were uninfected bone marrow-derived macrophages. TNF-alpha appeared to contribute to development of IL-10 hyporesponsiveness, because exposure of normal macrophages to TNF-alpha but not interferon-gamma reduced macrophage responsiveness to IL-10. Reverse transcriptase-PCR and flow cytometry demonstrated normal expression of the alpha and beta chains of the IL-10 receptor in macrophages from infected mice, suggesting that IL-10 hyporesponsiveness is not related to a change in receptor expression. The potential role of reduced IL-10 responsiveness in the chronicity of inflammation in this and other diseases is discussed.

Altered expression of Ape1/ref-1 in germ cell tumors and overexpression in NT2 cells confers resistance to bleomycin and radiation.

The human AP endonuclease (Ape1 or ref-1) DNA base excision repair (BER) enzyme is a multifunctional protein that has an impact on a wide variety of important cellular functions including oxidative signaling, transcription factor regulation, and cell cycle control. It acts on mutagenic AP (baseless) sites in DNA as a critical member of the DNA BER repair pathway. Moreover, Ape1/ref-1 stimulates the DNA-binding activity of transcription factors (Fos-Jun, nuclear factor-kappaB, Myb, ATF/cyclic AMP-responsive element binding protein family, HIF-1alpha, HLF, PAX, and p53) through a redox mechanism and thus represents a novel component of signal transduction processes that regulate eukaryotic gene expression. Ape1/ref-1 has also been shown to be closely linked to apoptosis associated with thioredoxin, and altered levels of Ape1/ref-1 have been found in some cancers. In a pilot study, we have examined Ape1/ref-1 expression by immunohistochemistry in sections of germ cell tumors (GCTs) from 10 patients with testicular cancer of various histologies including seminomas, yolk sac tumors, and malignant teratomas. Ape1/ref-1 was expressed at relatively high levels in the tumor cells of nearly all sections. We hypothesized that elevated expression of Ape1/ref-1 is responsible in part for the resistance to therapeutic agents. To answer this hypothesis, we overexpressed the Ape1/ref-1 cDNA in the GCT cell line NT2/D1 using retroviral gene transduction with the vector LAPESN. Using an oligonucleotide cleavage assay and immunohistochemistry to assess Ape1/ref-1 repair activity and expression, respectively, we found that the repair activity and relative Ape1/ref-1 expression in GCT cell lines are directly related. NT2/D1 cells transduced with Ape1/ref-1 exhibited 2-fold higher AP endonuclease activity in the oligonucleotide cleavage assay, and this was reflected in a 2-3-fold increase in protection against bleomycin. Lesser protection was observed with gamma-irradiation. We conclude that: (a) Ape1/ref-1 is expressed at relatively high levels in some GCTs; (b) elevated expression of Ape1/ref-1 in testicular cancer cell lines results in resistance to certain therapeutic agents; and (c) Ape1/ref-1 expression in GCT cell lines determined by immunohistochemistry and repair activity assays parallels the level of protection from bleomycin. We further hypothesize that elevated Ape1/ref-1 levels observed in human testicular cancer may be related to their relative resistance to therapy and may serve as a diagnostic marker for refractory disease. To our knowledge, this is the first example of overexpressing Ape1/ref-1 in a mammalian system resulting in enhanced protection to DNA-damaging agents.

In vivo reactivity of T cell clones isolated from mice with syngeneic graft-versus-host disease.

Syngeneic graft-versus-host disease (SGVHD) has been shown to occur in murine syngeneic radiation bone marrow chimeras following a short course of cyclosporine. To analyze the effector mechanisms present in diseased animals, four T cell clones (1D5, 1D8, 1C10, 2D8) were isolated from the spleens of C3H/HeN mice late in the disease course by cloning on irradiated syngeneic spleen cells. These clones were CD4+, alpha beta TCR+ and responded to I-Kk in vitro. In addition to I-Ek reactivity, three of the clones exhibited crossreactivity with the superantigen MIs 1a (mtv 7). Clones 1D5 and 1C10 were found to express TCR V beta chains (V beta 4 and V beta 8.1, respectively), which are normally present in the T cell repertoire of C3H/HeN mice. All SGVHD clones were found to be autoreactive in that they responded to syngeneic stimulator cells in the absence of xenogeneic serum proteins. To test in vivo activity, the 1D5 SGVHD clone was injected into the hind footpad of mice where it was shown to induce footpad swelling in a cell dose-dependent, I-Ek-specific manner in sublethally irradiated, but not normal mice. Histological analysis indicated that the clone induced dermal and subcutaneous edema that correlated directly with injection of 1D5 and not the control clone. Preliminary experiments suggested that the other three autoreactive clones behaved in a similar manner. These data are consistent with the involvement of a self-class II-specific CD4+ T cell in murine SGVHD.

Biphasic ordered induction of heme synthesis in differentiating murine erythroleukemia cells: role of erythroid 5-aminolevulinate synthase.

During dimethyl sulfoxide (DMSO)-stimulated differentiation of murine erythroleukemia (MEL) cells, one of the early events is the induction of the heme biosynthetic pathway. While recent reports have clearly demonstrated that GATA-1 is involved in the induction of erythroid cell-specific forms of 5-aminolevulinate synthase (ALAS-2) and porphobilinogen (PBG) deaminase and that cellular iron status plays a regulatory role for ALAS-2, little is known about regulation of the remainder of the pathway. In the current study, we have made use of a stable MEL cell mutant (MEAN-1) in which ALAS-2 enzyme activity is not induced by DMSO, hexamethylene bisacetamide (HMBA), or butyric acid. In this cell line, addition of 2% DMSO to growing cultures results in the normal induction of PBG deaminase and coproporphyrinogen oxidase but not in the induction of the terminal two enzymes, protoporphyrinogen oxidase and ferrochelatase. These DMSO-treated cells did not produce mRNA for beta-globin and do not terminally differentiate. In addition, the cellular level of ALAS activity declines rapidly after addition of DMSO, indicating that ALAS-1 must turn over rapidly at this time. Addition of 75 microM hemin alone to the cultures did not induce cells to terminally differentiate or induce any of the pathway enzymes. However, the simultaneous addition of 2% DMSO and 75 microM hemin caused the cells to carry out a normal program of terminal erythroid differentiation, including the induction of ferrochelatase and beta-globin. These data suggest that induction of the entire heme biosynthetic pathway is biphasic in nature and that induction of the terminal enzymes may be mediated by the end product of the pathway, heme. We have introduced mouse ALAS-2 cDNA into the ALAS-2 mutant cell line (MEAN-1) under the control of the mouse metallothionein promoter (MEAN-RA). When Cd and Zn are added to cultures of MEAN-RA in the absence of DMSO, ALAS-2 is induced but erythroid differentiation does not occur and cells continue to grow normally. In the presence of metallothionein inducers and DMSO, the MEAN-RA cells induce in a fashion similar to that found with the wild-type 270 MEL cells. Induction of the activities of ALAS, PBG deaminase, coproporphyrinogen oxidase, and ferrochelatase occurs. In cultures of MEAN-RA where ALAS-2 had been induced with Cd plus Zn 24 h prior to DMSO addition, onset of heme synthesis occurs more rapidly than when DMSO and Cd plus Zn are added simultaneously. This study reveals that induction of ALAS-2 alone is not sufficient to induce terminal differentiation of the MEAN-RA cells, and it does not appear that ALAS-2 alone is the rate-limiting enzyme of the heme biosynthetic pathway during MEL cell differentiation.

Marijuana and immunity: tetrahydrocannabinol-mediated inhibition of growth and phagocytic activity of the murine macrophage cell line, P388D1.

The effects of delta-9-tetrahydrocannabinol (THC) on the growth, DNA synthesis and phagocytic activity of P388D1, a murine macrophage cell line, were investigated. Incubating cell cultures with THC resulted in a dose-dependent inhibition of cell propagation and DNA synthesis. The magnitude of these effects was dependent upon the number of cells in the culture as well as the protein content in the culture medium. As the cell number increased, the THC effect decreased. Using cell cultures in which the cell concentration was standardized, THC (greater than or equal to 5 micrograms/ml) produced pronounced inhibitions of cell growth and DNA synthesis, while lower THC concentrations (less than or equal to 3 micrograms/ml) were less effective. Studies examining the phagocytic activity of the P388D1 cells indicating exposure to THC (5 micrograms/ml for 2 h) only marginally affected the association of latex beads with the external surface of the plasma membrane. However, the ability of these THC-treated cells to internalize the latex particles was severely depressed. Thus, the data indicate that THC inhibited the growth and functional activity of murine macrophages in vitro and suggests that the P388D1 cell line is a useful model to study the effects of cannabinoids on the phagocytic process.