Comparison of gene expression between left atria and left ventricles from non-diseased humans

We examine the reliability and accuracy of gene array technology in analyzing differences in gene expression between human non-diseased left atrium and left ventricle. We have used cDNA gene arrays and validated those data by carefully designed quantitative real-time polymerase chain reaction (PCR). We have identified pitfalls using cDNA gene array technology based on comparisons with other gene array studies and with changes reported for the levels of expression of the genes corresponding to these cDNAs. The high error rate reported here underscores the cautionary comments reported by others in this field.     

Proteasome involvement in the repair of DNA double-strand breaks

Affinity purification of the yeast 19S proteasome revealed the presence of Sem1 as a subunit. Its human homolog, DSS1, was found likewise to copurify with the human 19S proteasome. DSS1 is known to associate with the tumor suppressor protein BRCA2 involved in repair of DNA double-strand breaks (DSBs). We demonstrate that Sem1 is required for efficient repair of an HO-generated yeast DSB using both homologous recombination (HR) and nonhomologous end joining (NHEJ) pathways. Deletion of SEM1 or genes encoding other nonessential 19S or 20S proteasome subunits also results in synthetic growth defects and hypersensitivity to genotoxins when combined with mutations in well-established DNA DSB repair genes. Chromatin immunoprecipitation showed that Sem1 is recruited along with the 19S and 20S proteasomes to a DSB in vivo, and this recruitment is dependent on components of both the HR and NHEJ repair pathways, suggesting a direct role of the proteasome in DSB repair.     

The use of diagnostic radiology to detect shell irregularities in the New Zealand paua (abalone) Haliotis iris

A method is described for the non-destructive, non-invasive, detection of shell lesions in the New Zealand paua, a marine gastropod Haliotis iris using diagnostic radiology. The X-ray method reliably detected the presence of shell lesions in 96% of the cases examined once lesion dimensions exceeded 6.2 x 7.1 mm. The extent of lesions above this size can be reliably and accurately determined from X-ray images viewed on a video display unit (VDU). Biofouling on the outside of the shell can cause misdiagnoses. This method is a significant animal welfare refinement in the identification of marine gastropods with shell lesions, when compared with traditional techniques which kill the animals.     

Spectral correspondence between visual spectral sensitivity and bioluminescence emission spectra in the click beetle Pyrophorus punctatissimus (Coleoptera: Elateridae)

The presence of two spectral mechanisms, near-ultraviolet and green (lambda(max)=545nm), is strongly suggested by electroretinographic visual spectral sensitivity curves obtained under dark and red chromatic adaptation conditions in the compound eyes of the click beetle Pyrophorus punctatissimus. The bioluminescence emission of the dorsal prothoracic lanterns is deep green (lambda(max)=543nm) and that of the ventral abdominal lantern is lime green (lambda(max)=556nm) in colour in P. punctatissimus. A broad green visual receptor would detect both deep green and lime green bioluminescent optical signals.     

Interleukin-2-producing helper T lymphocyte precursor frequency and rejection: a longitudinal cellular study after cardiac transplantation

Interleukin-2-producing helper T lymphocyte precursors (HTLp) in the recipient recognize donor alloantigen expressed by the transplanted organ. The frequency of these reactive cells in the peripheral blood was determined and correlated with rejection episodes. Endomyocardial biopsy is generally used to quantify cardiac allograft rejection and guide immunotherapy. While non-invasive techniques have been investigated, none of these has demonstrated sufficient sensitivity or specificity to replace myocardial biopsy. Twelve cardiac transplant recipients were assessed over a 1 year period using limiting dilution analysis, to determine the frequency of HTLp in response to cadaver donor splenocytes. The IL-2-dependent mouse cell line CTLL-2 was used to measure the IL-2 present and the precursor frequency was calculated using maximum likelihood estimation. In the months immediately post transplantation, six of the 12 recipients displayed an association with increases in HTLp frequency, which preceded histologically detectable rejection. The second six recipients had fewer rejection episodes and achieved 'acceptance' of their graft sooner. Once 'acceptance' was achieved, the association between IL-2 HTLp frequency and rejection was no longer apparent. The ability to identify two groups of patients on the basis of IL-2 HTLp frequency clearly highlights the heterogenous nature of the response to the graft and this emphasizes the need to monitor other cytokines, which may influence the functioning of effector T cells.     

Moderate weight loss reduces renin and aldosterone but does not influence basal or stimulated pituitary-adrenal axis function.

Body fat mass and nutrition influence secretion of the adrenocortical hormones--aldosterone and cortisol--via several mechanisms. However, there are no data on adrenocortical function following widely prescribed mild diet-induced weight loss (10%) in obese subjects. In the present study, 25 healthy obese volunteers (BMI 32.9+/-4.3 kg/m (2)) followed a 30% calorie restricted diet over 12 weeks. Hypothalamic-pituitary-adrenal (HPA) axis function was assessed by 24-hour urine free cortisol/cortisone and a 1 mcg ACTH stimulation test with measurement of total and free cortisol and corticosteroid-binding globulin (CBG). The renin-angiotensin-aldosterone system (RAAS) was assessed by measurement of plasma aldosterone and renin under salt depleted (30 mmol/d) and loading (250 mmol/d) conditions. Volunteers' weight fell by 8.5+/-0.8 kg (8.9+/-0.7%) and seated systolic blood pressure fell by 8.7+/-2.7 mmHg and diastolic blood pressure by 7.0+/-1.4 mmHg (p<0.01). Plasma aldosterone and renin levels fell significantly with weight loss (aldosterone: 853+/-156-635+/-73 pmol/l; renin: 35.4+/-7-24+/-3 mU/l, both p<0.05). The volunteers were relatively salt insensitive (mean arterial pressure change with salt intake: 4 mmHg) and this was not affected by weight loss. Moderate weight loss had no effect on 24-hour urine free cortisol/cortisone, or on basal, or ACTH-stimulated free and total cortisol, or CBG. Hence this conventional weight loss program reduces blood pressure and activity of the RAAS via an effect on renin release. Despite various described influences of fat mass and energy restriction on HPA axis function, there were no changes in basal and stimulated HPA axis function with moderate weight loss. There may be a threshold effect of weight loss/energy restriction required to alter HPA axis function, or moderate weight loss may lead to a counterbalanced effect of stimulatory and inhibitory influences on HPA axis function.     

PERCHED AT THE MITO‐NUCLEAR CROSSROADS: DIVERGENT MITOCHONDRIAL LINEAGES CORRELATE WITH ENVIRONMENT IN THE FACE OF ONGOING NUCLEAR GENE FLOW IN AN AUSTRALIAN BIRD

Relationships among multilocus genetic variation, geography, and environment can reveal how evolutionary processes affect genomes. We examined the evolution of an Australian bird, the eastern yellow robin Eopsaltria australis, using mitochondrial (mtDNA) and nuclear (nDNA) genetic markers, and bioclimatic variables. In southeastern Australia, two divergent mtDNA lineages occur east and west of the Great Dividing Range, perpendicular to latitudinal nDNA structure. We evaluated alternative scenarios to explain this striking discordance in landscape genetic patterning. Stochastic mtDNA lineage sorting can be rejected because the mtDNA lineages are essentially distinct geographically for > 1500 km. Vicariance is unlikely: the Great Dividing Range is neither a current barrier nor was it at the Last Glacial Maximum according to species distribution modeling; nuclear gene flow inferred from coalescent analysis affirms this. Female philopatry contradicts known female‐biased dispersal. Contrasting mtDNA and nDNA demographies indicate their evolutionary histories are decoupled. Distance‐based redundancy analysis, in which environmental temperatures explain mtDNA variance above that explained by geographic position and isolation‐by‐distance, favors a nonneutral explanation for mitochondrial phylogeographic patterning. Thus, observed mito‐nuclear discordance accords with environmental selection on a female‐linked trait, such as mtDNA, mtDNA–nDNA interactions or genes on W‐chromosome, driving mitochondrial divergence in the presence of nuclear gene flow.     

Step on it: can footprints from tracking tunnels be used to identify lizard species?

There are few effective or efficient established methods for monitoring cryptic herpetofauna. Footprint tracking tunnels are routinely used to index small mammal populations, but also have potential for monitoring herpetofauna. We evaluated the utility of tracking tunnels for identification of New Zealand lizards using captive- and wild-sourced animals (four skink and eight gecko species). All skink prints that we obtained were indistinct or obscure, but we obtained relatively clear, measurable prints for all gecko species. We found that identification to species level was possible for the two gecko species for which we had a large sample—Naultinus gemmeus and Woodworthia ‘Otago large’—using linear discriminant analysis (the best model correctly assigned 96.1% of individuals). Our findings suggest that footprints from tracking tunnels may be used to distinguish between species of geckos. Additional research is needed to assess the ability to further discriminate intra- and inter-genera lizard footprints from tracking tunnels, and the utility of the technique for surveying and monitoring lizard populations.     

PCR gut analysis reveals that Tenuiphantes tenuis (Araneae: Linyphiidae) is a potentially significant predator of Argentine stem weevil,Listronotus bonariensis (Coleoptera: Curculionidae), in New Zealand pastures

Polymerase chain reaction (PCR) gut analysis was conducted on specimens of the introduced spider Tenuiphantes tenuis collected from dairy pasture in Canterbury, New Zealand. PCR primers were specifically designed to amplify a fragment of the mitochondrial gene cytochrome c oxidase subunit 1 (COI) from Listronotus bonariensis and revealed that this major pasture pest species is consumed in the field by T. tenuis. The field predation rate of L. bonariensis by T. tenuis was estimated from our PCR results together with published data on the degradation of DNA and the density of T. tenuis in Canterbury pastures. We found that T. tenuis is a potentially significant predator of L. bonariensis in New Zealand pastures.     

Immune responses to stress after stress management training in patients with rheumatoid arthritis

Introduction

Psychological stress may alter immune function by activating physiological stress pathways. Building on our previous study, in which we report that stress management training led to an altered self-reported and cortisol response to psychological stress in patients with rheumatoid arthritis (RA), we explored the effects of this stress management intervention on the immune response to a psychological stress task in patients with RA.

Methods

In this study, 74 patients with RA, who were randomly assigned to either a control group or a group that received short stress management training, performed the Trier Social Stress Test (TSST) 1 week after the intervention and at a 9-week follow-up. Stress-induced changes in levels of key cytokines involved in stress and inflammatory processes (for example, interleukin (IL)-6 and IL-8) were assessed.

Results

Basal and stress-induced cytokine levels were not significantly different in patients in the intervention and control groups one week after treatment, but stress-induced IL-8 levels were lower in patients in the intervention group than in the control group at the follow-up assessment.

Conclusions

In line with our previous findings of lower stress-induced cortisol levels at the follow-up of stress management intervention, this is the first study to show that relatively short stress management training might also alter stress-induced IL-8 levels in patients with RA. These results might help to determine the role of immunological mediators in stress and disease.

Trial registration

The Netherlands National Trial Register (NTR1193)