The longitudinal behavioral effects of acute exposure to galactic cosmic radiation in female C57BL/6J mice: implications for deep space missions, female crews, and potential antioxidant countermeasures.

Galactic cosmic radiation (GCR) is an unavoidable risk to astronauts that may affect mission success. Male rodents exposed to 33-beam-GCR (33-GCR) show short-term cognitive deficits but reports on female rodents and long-term assessment is lacking. Here we asked: What are the longitudinal behavioral effects of 33-GCR on female mice? Also, can an antioxidant/anti-inflammatory compound mitigate the impact of 33-GCR? Mature (6-month-old) C57BL/6J female mice received the antioxidant CDDO-EA (400 µg/g of food) or a control diet (vehicle, Veh) for 5 days and either Sham-irradiation (IRR) or whole-body 33-GCR (0.75Gy) on the 4th day. Three-months post-IRR, mice underwent two touchscreen-platform tests: 1) location discrimination reversal (which tests behavior pattern separation and cognitive flexibility, two abilities reliant on the dentate gyrus) and 2) stimulus-response learning/extinction. Mice then underwent arena-based behavior tests (e.g. open field, 3-chamber social interaction). At the experiment end (14.25-month post-IRR), neurogenesis was assessed (doublecortin-immunoreactive [DCX+] dentate gyrus neurons). Female mice exposed to Veh/Sham vs. Veh/33-GCR had similar pattern separation (% correct to 1st reversal). There were two effects of diet: CDDO-EA/Sham and CDDO-EA/33-GCR mice had better pattern separation vs. their respective control groups (Veh/Sham, Veh/33-GCR), and CDDO-EA/33-GCR mice had better cognitive flexibility (reversal number) vs. Veh/33-GCR mice. Notably, one radiation effect/CDDO-EA countereffect also emerged: Veh/33-GCR mice had worse stimulus-response learning (days to completion) vs. all other groups, including CDDO-EA/33-GCR mice. In general, all mice show normal anxiety-like behavior, exploration, and habituation to novel environments. There was also a change in neurogenesis: Veh/33-GCR mice had fewer DCX+ dentate gyrus immature neurons vs. Veh/Sham mice. Our study implies space radiation is a risk to a female crew's longitudinal mission-relevant cognitive processes and CDDO-EA is a potential dietary countermeasure for space-radiation CNS risks.

Raised levels of metal ions in the blood in patients who have undergone uncemented metal-on-polyethylene Trident-Accolade total hip replacement.

The issues surrounding raised levels of metal ions in the blood following large head metal-on-metal total hip replacement (THR), such as cobalt and chromium, have been well documented. Despite the national popularity of uncemented metal-on-polyethylene (MoP) THR using a large-diameter femoral head, few papers have reported the levels of metal ions in the blood following this combination. Following an isolated failure of a 44 mm Trident-Accolade uncemented THR associated with severe wear between the femoral head and the trunnion in the presence of markedly elevated levels of cobalt ions in the blood, we investigated the relationship between modular femoral head diameter and the levels of cobalt and chromium ions in the blood following this THR. A total of 69 patients received an uncemented Trident-Accolade MoP THR in 2009. Of these, 43 patients (23 men and 20 women, mean age 67.0 years) were recruited and had levels of cobalt and chromium ions in the blood measured between May and June 2012. The patients were then divided into three groups according to the diameter of the femoral head used: 12 patients in the 28 mm group (controls), 18 patients in the 36 mm group and 13 patients in the 40 mm group. A total of four patients had identical bilateral prostheses in situ at phlebotomy: one each in the 28 mm and 36 mm groups and two in the 40 mm group. There was a significant increase in the mean levels of cobalt ions in the blood in those with a 36 mm diameter femoral head compared with those with a 28 mm diameter head (p = 0.013). The levels of cobalt ions in the blood were raised in those with a 40 mm diameter head but there was no statistically significant difference between this group and the control group (p = 0.152). The levels of chromium ions in the blood were normal in all patients. The clinical significance of this finding is unclear, but we have stopped using femoral heads with a diameter of ≤ 36 mm, and await further larger studies to clarify whether, for instance, this issue particularly affects this combination of components.

Fracture healing assessment comparing stiffness measurements using radiographs.

Based on published reports, we presumed radiographs would be unreliable as a sole measure of fracture healing. To confirm this presumption we correlated radiographic fracture healing assessments with fracture stiffness measurements. We showed 100 plain radiographs of fractures with corresponding fracture stiffness measurements to 92 observers. The radiographs were shown twice to assess intraobserver variation. Observers were divided into three groups and asked to determine whether each fracture had healed (union corresponded to a fracture stiffness greater than 15 nm/degrees). Group 1 based fracture healing on the general appearance of healing. Groups 2 and 3 assessed fracture healing based on the number of cortices bridged by callus. In Group 2, the fracture was considered healed if two or more cortices were bridged on both radiographic views and in Group 3 if three or more cortices were bridged by callus. All groups performed poorly. There was no difference in terms of correct prediction of healing between methods, although there was a trend toward more reliability with cortical callus bridging assessment. We found substantial intraobserver variability, which improved using cortical bridging methods. Observers were less reliable at predicting healing when there was a metaphyseal extension to a diaphyseal fracture.

Development of signature-tagged mutagenesis in Burkholderia pseudomallei to identify genes important in survival and pathogenesis.

Burkholderia pseudomallei, the causative agent of melioidosis, is an important human pathogen in Southeast Asia and northern Australia for which a vaccine is unavailable. A panel of 892 double signature-tagged mutants was screened for virulence using an intranasal BALB/c mouse model of infection. A novel DNA tag microarray identified 33 mutants as being attenuated in spleens, while 6 were attenuated in both lungs and spleens. The transposon insertion sites in spleen-attenuated mutants revealed genes involved in several stages of capsular polysaccharide biosynthesis and DNA replication and repair, a putative oxidoreductase, ABC transporters, and a lipoprotein that may be important in intercellular spreading. The six mutants identified as missing in both lungs and spleens were found to have insertions in recA involved in the SOS response and DNA repair; putative auxotrophs of leucine, threonine, p-aminobenzoic acid, and a mutant with an insertion in aroB causing auxotrophy for aromatic compounds were also found. Murine challenge studies revealed partial protection in BALB/c mice vaccinated with the aroB mutant. The refined signature-tagged mutagenesis approach developed in this study was used to efficiently identify attenuating mutants from this highly pathogenic species and could be applied to other organisms.

A 12-month follow-up study of self-management training for people with chronic disease: are changes maintained over time?

OBJECTIVE: A previous study reported some improved outcomes at 4-month follow-up after attendance on a lay-led, chronic disease self-management course (CDSMC). The purpose of this study was to determine whether changes were maintained over time (i.e. at 12 months) and to describe participants' current use of self-management techniques. DESIGN: The study was a 12-month follow-up of a sample of 171 participants who attended a CDSMC in the UK. METHOD: Data were collected by self-administered questionnaires mailed to participants 12 months after they commenced a CDSMC and via telephone interviews with a sub-sample. RESULTS: The sample had a mean age of 54 years, mean disease duration of 16 years, 73% were women, and chronic diseases included endometriosis, depression, diabetes, myalgic encephalomyelitis, osteoporosis and polio. The significant improvements in outcomes identified at 4 months (i.e. cognitive symptom management, self-efficacy, communication with physician, fatigue, anxious and depressed moods and health distress) were sustained at 12 months. No significant changes between 4- and 12-month assessments were found on any study variables. Interview data confirmed that participants continued to use some of the self-management techniques learned on the course. CONCLUSION: Attendance on the CDSMC may lead to longer-term changes in key outcomes such as self-efficacy, use of some self-management behaviours and some aspects of health status (e.g. fatigue, depressed mood).

Volunteer, lay tutors' experiences of the Chronic Disease Self-Management Course: being valued and adding value.

Chronic disease is a public health issue that could be addressed, in part, by increasing the ability of individuals to better manage their condition and its consequences on a day-to-day basis. One intervention designed to facilitate this is the Chronic Disease Self Management Course (CDSMC) that is delivered by volunteer, lay tutors who themselves have a chronic disease. Although there is growing evidence of course effectiveness for participants, the experiences of tutors have been neglected. This study aims to address this omission. Telephone interviews were conducted with 11 (six male) tutors: all interviews were transcribed and thematically analysed. Being a volunteer lay-tutor was perceived to be an enjoyable and valuable experience despite the challenges associated with course delivery, such as organizational demands and managing the diverse needs of mixed groups of chronic disease participants that led to a tension between disease-specific needs and the generic approach of the course. Being valued and adding value to the lives of others were key benefits of being a volunteer tutor, along with increased confidence that they were doing something positive for others. Course delivery prompted the initiation and maintenance of tutors' own self-management behaviours.

Self-management training for people with chronic disease: an exploratory study.

OBJECTIVE: To determine the effectiveness of a community-based Chronic Disease Self-management Course (CDC) for UK participants with a range of chronic diseases. DESIGN: The study was a multiple baseline, pre-test post test design with a sample of 185 participants who attended a CDC delivered in community settings by lay tutors, in the UK. METHOD: Data were collected by self-completed questionnaires before attendance and at four-month follow-up. RESULTS: The sample comprised 72% women (mean age = 53 years, mean disease duration = 16 years). The main chronic diseases included endometriosis, depression, diabetes, myalgic encephalomyelitis, osteoporosis and polio. Adjusting for baseline values and gender, small to moderate increases were found on cognitive symptom management, self-efficacy (disease and symptoms) and communication with physician. A similar sized decrease was found on fatigue, and small decreases were evident on anxious and depressed moods, and health distress. There were no changes in the use of health care resources, or on self-reported exercise behaviour. CONCLUSION: The results of this exploratory study suggest that self-management training for people with chronic diseases can offer benefits in terms of enhanced self-efficacy, greater use of cognitive behavioural techniques, and improvement in some aspects of physical and psychological well-being.

A study of titanium nitride diffusion barriers between aluminum and silicon by X-ray absorption spectroscopy: the Si, Ti and N results.

We report a multi-elment, multi-edge and multi-detection mode X-ray photoabsorption study of a series of Al/TiN(x)/Si(100) thin films as a function of the TiN(x) film thickness (100A-500A) and of the annealing temperature (400 degrees C-600 degrees C). The Si K- and L-edge results show that Si does not diffuse to the surface for all the films. The high resolution Ti L-edge and N K-edge spectra show that the TiN(x) layer undergoes a dramatic chemical reaction with the gradual increase in the annealing temperature. This chemical reaction stabilizes at 560 degrees C at which the TiN(x) film is known to fail to act as an effective diffusion barrier between Al and Si.

Production of matrix metalloproteinases in response to mycobacterial infection.

Matrix metalloproteinases (MMPs) constitute a large family of enzymes with specificity for the various proteins of the extracellular matrix which are implicated in tissue remodeling processes and chronic inflammatory conditions. To investigate the role of MMPs in immunity to mycobacterial infections, we incubated murine peritoneal macrophages with viable Mycobacterium bovis BCG or Mycobacterium tuberculosis H37Rv and assayed MMP activity in the supernatants by zymography. Resting macrophages secreted only small amounts of MMP-9 (gelatinase B), but secretion increased dramatically in a dose-dependent manner in response to either BCG or M. tuberculosis in vitro. Incubation with mycobacteria also induced increased MMP-2 (gelatinase A) activity. Neutralization of tumor necrosis alpha (TNF-alpha), and to a lesser extent interleukin 18 (IL-18), substantially reduced MMP production in response to mycobacteria. Exogenous addition of TNF-alpha or IL-18 induced macrophages to express MMPs, even in the absence of bacteria. The immunoregulatory cytokines gamma interferon (IFN-gamma), IL-4, and IL-10 all suppressed BCG-induced MMP production, but through different mechanisms. IFN-gamma treatment increased macrophage secretion of TNF-alpha but still reduced their MMP activity. Conversely, IL-4 and IL-10 seemed to act by reducing the amount of TNF-alpha available to the macrophages. Finally, infection of BALB/c or severe combined immunodeficiency (SCID) mice with either BCG or M. tuberculosis induced substantial increases in MMP-9 activity in infected tissues. In conclusion, we show that mycobacterial infection induces MMP-9 activity both in vitro and in vivo and that this is regulated by TNF-alpha, IL-18, and IFN-gamma. These findings indicate a possible contribution of MMPs to tissue remodeling processes that occur in mycobacterial infections.

Characterization of auxotrophic mutants of Mycobacterium tuberculosis and their potential as vaccine candidates.

Auxotrophic mutants of Mycobacterium tuberculosis have been proposed as new vaccine candidates. We have analyzed the virulence and vaccine potential of M. tuberculosis strains containing defined mutations in genes involved in methionine (metB), proline (proC), or tryptophan (trpD) amino acid biosynthesis. The metB mutant was a prototrophic strain, whereas the proC and trpD mutants were auxotrophic for proline and tryptophan, respectively. Following infection of murine bone marrow-derived macrophages, H37Rv and the metB mutant strain survived intracellularly for over 10 days, whereas over 90% of proC and trpD mutants were killed during this time. In SCID mice, both H37Rv and the metB mutant were highly virulent, with mouse median survival times (MST) of 28.5 and 42 days, respectively. The proC mutant was significantly attenuated (MST, 130 days), whereas the trpD mutant was essentially avirulent in an immunocompromised host. Following infection of immunocompetent DBA mice with H37Rv, mice survived for a median of 83.5 days and the metB mutant now showed a clear reduction in virulence, with two of five infected mice surviving for 360 days. Both proC and trpD mutants were avirulent (MST of >360 days). In vaccination studies, prior infection with either the proC or trpD mutant gave protection equivalent (proC mutant) to or better (trpD mutant) than BCG against challenge with M. tuberculosis H37Rv. In summary, proC and trpD genes are essential for the virulence of M. tuberculosis, and mutants with disruptions in either of these genes show strong potential as vaccine candidates.

Bystander activation of CD8+ T cells contributes to the rapid production of IFN-gamma in response to bacterial pathogens.

The bacterium Burkholderia pseudomallei causes a life-threatening disease called melioidosis. In vivo experiments in mice have identified that a rapid IFN-gamma response is essential for host survival. To identify the cellular sources of IFN-gamma, spleen cells from uninfected mice were stimulated with B. pseudomallei in vitro and assayed by ELISA and flow cytometry. Costaining for intracellular IFN-gamma vs cell surface markers demonstrated that NK cells and, more surprisingly, CD8(+) T cells were the dominant sources of IFN-gamma. IFN-gamma(+) NK cells were detectable after 5 h and IFN-gamma(+) CD8(+) T cells within 15 h after addition of bacteria. IFN-gamma production by both cell populations was inhibited by coincubation with neutralizing mAb to IL-12 or IL-18, while a mAb to TNF had much less effect. Three-color flow cytometry showed that IFN-gamma-producing CD8(+) T cells were of the CD44(high) phenotype. The preferential activation of NK cells and CD8(+) T cells, rather than CD4(+) T cells, was also observed in response to Listeria monocytogenes or a combination of IL-12 and IL-18 both in vitro and in vivo. This rapid mechanism of CD8(+) T cell activation may be an important component of innate immunity to intracellular pathogens.

Adrenaline suppression of the macrophage nitric oxide response to lipopolysaccharide is associated with differential regulation of tumour necrosis factor-alpha and interleukin-10.

Adrenaline is a catecholamine hormone secreted by the adrenal medulla in response to acute stress. Previous studies have shown that adrenaline suppresses the nitric oxide (NO) response of murine macrophages (M phi s) stimulated in vitro with lipopolysaccharide (LPS). We have now extended these studies to examine the effects of adrenaline on the production of tumour necrosis factor alpha (TNF-alpha) and interleukin-10 (IL-10). Our results showed that NO, TNF-alpha and IL-10 were concurrently produced following in vitro LPS (10 micrograms/ml) stimulation of murine peritoneal M phi s. Adrenaline suppressed both NO and TNF-alpha with concomitant up-regulation of the IL-10 response above that seen with LPS alone. In this in vitro model of LPS stimulation we demonstrated that TNF-alpha was required for NO production, as the TNF-alpha neutralizing monoclonal antibody, TN3.19.12, abolished the response; in contrast, IL-10 suppressed NO. In order to determine any functional consequence of adrenaline-mediated IL-10 augmentation on NO production, M phi s were stimulated with LPS and specific neutralizing anti-IL-10 antibodies were added to the cultures. The LPS NO response was suppressed to 43% of the control value by adrenaline (10(-8) M) and an irrelevant control antibody had no effect on the adrenaline-mediated inhibition of NO, but anti-IL-10 treatment restored the NO response to levels similar to those observed with LPS alone. Furthermore, we demonstrated that exogenous TNF-alpha, at a dose range of 1.9-50 ng per ml, also restored the nitrite response to LPS in the presence of adrenaline. Together, the observations that neutralization of IL-10 and addition of TNF-alpha abrogate adrenaline's inhibition of NO, suggest that this hormone suppresses NO partly through up-regulation of IL-10 which, in turn, may suppress TNF-alpha that is required for NO production. Finally, we also observed that the M phi-activating cytokine, interferon-gamma (IFN-gamma), attenuated the inhibitory effect of adrenaline on the LPS NO response.

Early nonspecific immune responses and immunity to blood-stage nonlethal Plasmodium yoelii malaria.

The early role of natural killer cells and gamma delta T cells in the development of protective immunity to the blood stage of nonlethal Plasmodium yoelii infection was studied. Splenic cytokine levels were measured 24 h after infection of natural killer cell-depleted immunodeficient and littermate mice or transiently T-cell-depleted normal mice. Splenic gamma interferon levels were significantly increased above background in immunodeficient and littermate mice 24 h after infection. Depletion of natural killer cells resulted in markedly depressed gamma interferon levels and poor control of parasitemia, particularly in severe combined immunodeficient mice. In the littermates, gamma interferon levels were partially reduced, but parasitemias were resolved normally. However, in athymic mice, natural killer cell depletion had no effect on gamma interferon production. Levels of tumor necrosis factor alpha were increased in all animals 24 h after infection, and responses were not affected by natural killer cell depletion. However, in T-cell-depleted animals, both gamma interferon and tumor necrosis factor alpha levels were decreased 24 h after infection, and depleted mice were unable to control their parasitemia. These results suggest that the early production of both cytokines is important in the early control of parasitemia and that both natural killer and gamma delta T cells contribute equally towards their production. The data also suggest that the subsequent resolution of infection requires early production of gamma interferon, which might act by switching on the appropriate T-helper-cell subsets and other essential parasitotoxic effector mechanisms.

First results from the Canadian SGM beamline at SRC.

The first experimental results obtained from the Canadian SGM beamline at SRC (Synchrotron Radiation Centre, University of Wisconsin-Madison, USA) are reported. The beamline is based on the Dragon-type design, with a constant deviation angle, using photons from a second-generation bending-magnet light source. The medium-energy grating on this beamline covers a photon energy range from 240 to 700 eV, with a ruling density of 600 lines mm(-1). A maximum resolving power of approximately 10000 is achieved at a photon energy of approximately 400 eV. Gas-phase absorption spectra collected at the N, O and C K-edges are presented to demonstrate the excellent performance of this beamline. High-resolution absorption spectra of some C- and Ti-containing solid-state samples are also reported.

Variable-energy photoelectron spectroscopy of substituted rhenium and manganese pentacarbonyls: molecular orbital assignments and the interatomic resonant effect.

High-resolution variable-energy photoelectron spectra of M(CO)5X [M = Re, X = Re(CO)5, Cl, Br, and I; and M = Mn, X = Mn(CO)5 and Br] are reported. Tunable synchrotron radiation is used to distinguish the Re 5d and Br 4p orbital based peaks for the controversial Re(CO)5Br. Our results provide firm molecular orbital assignments for all of these molecules. The valence orbital in the ordering of ionization energies for M(CO)5Cl (M = Mn and Re) and Mn(CO)5Br is a 1(M-X) > e(X) > b2(M) > e(M); but for M(CO)5I (M = Mn and Re) and Re(CO)5Br the ordering is a1(M-X) > e(M) > b2(M) > e(X). The crossover of the HOMO in the Re molecules due to the change in the halogen electronegativities occurs at Re(CO)5Br. The metal np-->nd resonance is observed for all of these molecules. For molecules like M2(CO)10 (M = Re and Mn) and Mn(CO)5Br, the observation of this np-->nd resonance is useful in assigning the metal nd based orbitals in their valence level spectra. However, for molecules like Re(CO)5X (X = Br and Cl), a np-->nd type resonance is observed on bands arising from both Re 5d and halogen mp based orbitals. This new resonant effect on the ligand-based orbitals is shown to be mainly due to the interatomic resonant effect. The core and valence level chemical shifts of these compounds are treated using Jolly's approach to confirm the assignments for the valence level spectra of some of these molecules. The high-resolution inner valence and core level spectra of these compounds are reported. Broadening of Re 4f, Br 3d, and I 4d core level spectra is discussed. The Auger peaks are observed in the high-resolution, high-intensity Br 3d of Re(CO)5Br and I 4d of Re(CO)5I spectra.

Cytokine and chemokine responses following pulmonary challenge with Aspergillus fumigatus: obligatory role of TNF-alpha and GM-CSF in neutrophil recruitment.

Aspergillus fumigatus causes life-threatening invasive pulmonary aspergillosis in the immunocompromised patient. In this study we have used a murine model of intratracheal challenge with A. fumigatus to investigate the recruitment of inflammatory cells in the lung and the expression of proinflammatory cytokines and chemokines. Our results show that A. fumigatus causes an acute pulmonary inflammatory response which is dominated by neutrophils and to a lesser extent macrophages. During the peak of infection, proinflammatory cytokines (TNF-alpha, GM-CSF and IL-1beta) and chemokines (MIP-1alpha, MCP-1 and MIP-2), are induced within the lung. Furthermore, treatment of mice with neutralizing anti-TNF-alpha and anti-GM-CSF mAbs reduced the influx of neutrophils into the lung and delayed fungal clearance. Our observations show that Aspergillus conidia are effective inducers of host chemokine responses both in vitro and in vivo. Furthermore, TNF-alpha and GM-CSF play a central role in the recruitment of neutrophils into the lung in response to this clinically important pathogen.

Obligatory role of gamma interferon for host survival in a murine model of infection with Burkholderia pseudomallei.

Burkholderia pseudomallei, the causative agent of melioidosis, is a gram-negative bacterium capable of causing either acute lethal sepsis or chronic but eventually fatal disease in infected individuals. However, despite the clinical importance of this infection in areas where it is endemic, there is essentially no information on the mechanisms of protective immunity to the bacterium. We describe here a murine model of either acute or chronic infection with B. pseudomallei in Taylor Outbred (TO) mice which mimics many features of the human pathology. Intraperitoneal infection of TO mice at doses of >10(6) CFU resulted in acute septic shock and death within 2 days. In contrast, at lower doses mice were able to clear the inoculum from the liver and spleen over a 3- to 4-week period, but persistence of the organism at other sites resulted in a chronic infection of between 2 and 16 months duration which was eventually lethal in all of the animals tested. Resistance to acute infection with B. pseudomallei was absolutely dependent upon the production of gamma interferon (IFN-gamma) in vivo. Administration of neutralizing monoclonal antibody against IFN-gamma lowered the 50% lethal dose from >5 x 10(5) to ca. 2 CFU and was associated with 8,500- and 4,400-fold increases in the bacterial burdens in the liver and spleen, respectively, together with extensive destruction of lymphoid architecture in the latter organ within 48 h. Neutralization of either tumor necrosis factor alpha or interleukin-12 but not granulocyte-macrophage colony-stimulating factor, also increased susceptibility to infection in vivo. Together, these results provide the first evidence of a host protective mechanism against B. pseudomallei. The rapid production of IFN-gamma within the first day of infection determines whether the infection proceeds to an acute lethal outcome or becomes chronic.