Strong topographic sheltering effects lead to spatially complex treeline advance and increased forest density in a subtropical mountain region

Altitudinal treelines are typically temperature limited such that increasing temperatures linked to global climate change are causing upslope shifts of treelines worldwide. While such elevational increases are readily predicted based on shifting isotherms, at the regional level the realized response is often much more complex, with topography and local environmental conditions playing an important modifying role. Here, we used repeated aerial photographs in combination with forest inventory data to investigate changes in treeline position in the Central Mountain Range of Taiwan over the last 60 years. A highly spatially variable upslope advance of treeline was identified in which topography is a major driver of both treeline form and advance. The changes in treeline position that we observed occurred alongside substantial increases in forest density, and lead to a large increase in overall forest area. These changes will have a significant impact on carbon stocking in the high altitude zone, while the concomitant decrease in alpine grassland area is likely to have negative implications for alpine species. The complex and spatially variable changes that we report highlight the necessity for considering local factors such as topography when attempting to predict species distributional responses to warming climate.

Using heart failure instruments to determine when to refer heart failure patients to palliative care

AIM

The purpose of this study was to determine whether the Edmonton Symptom Assessment Scale (ESAS) or the Palliative Performance Scale (PPS) are associated with traditionally used scores for heart failure patients -- specifically, the Minnesota Living with Heart Failure Questionnaire (MLHFQ), an overall health visual analog scale (VAS), and the Seattle Heart Failure Model (SHFM). Furthermore, we sought to determine whether the PPS or the ESAS provided additional information on quality of life, symptom severity, or prognosis above that provided by the traditional scores for patients with heart failure.

METHODS

We administered the ESAS, MLHFQ, VAS, PPS, and SHFM in a shuffled manner to 78 New York Heart Association Functional Classification (NYHA-FC) Ill-IV ambulatory heart failure patients. Pearson's r correlation was used to determine whether the scores from the ESAS and PPS correlated with the scores from the MLHFQ, VAS, and SHFM.

RESULTS

The sample was predominately male (62.8 percent), mean age 60.1 +/- 13 years, with a diagnosis of idiopathic cardiomyopathy (45 percent). Moderate correlations were found between the ESAS and MLHFQ (r = 0.483, p < 0.01), the ESAS and VAS (r = -0.345, p < 0.01), the PPS and MLHFQ (r = -0.54, p < 0.01), and the PPS and VAS (r = 0.53, p < 0.01). There was no significant correlation between the PPS and SHFM.

CONCLUSION

The results of this study suggest that administration of the ESAS and PPS provides additional information on symptom severity and functional decline for patients with heart failure. Standardized administration of these scales may aid in the assessment and evaluation of heart failure patients.

Can the early condition at admission of a high-risk infant aid in the prediction of mortality and poor neurodevelopmental outcome? A population study in Australia

AIM

The aim of this article was to evaluate the Revised Clinical Risk Index for Babies' (CRIB-II) severity of illness score as a predictor of moderate to severe functional disability (FD) in very premature infants.

METHODS

Population study of infants born <29 weeks' gestation cared for in all Neonatal Intensive Care Unit in New South Wales and the Australian Capital Territory between 1998 and 2003. FD at 2-3 years corrected age was defined as developmental delay (quotient < 2 standard deviation), non-ambulatory cerebral palsy (needing aids to walk), blindness (acuity <6/60 in better eye) or deafness (hearing aids). Sensitivity and specificity of CRIB-II scores to predict FD were performed by receiver operating characteristic curve analysis.

RESULTS

Of study population of 2210, 480 (21.7%) died before hospital discharge. Among 1328 infants assessed, 217 (16.3%) had FD, 109 (8.2%) developmental delay, 75 (5.6%) cerebral palsy and 54 (4.1%) blindness or deafness. CRIB-II performed significantly better than gestation or birthweight (BW) alone in predicting mortality (area under the curve (AUC) ± standard error 0.83 ± 0.01, vs. 0.78 ± 0.01 and 0.76 ± 0.01, respectively). CRIB-II scores were significantly higher in FD than non-FD children (11.9 ± 2.9 vs. 10.1 ± 2.6), but the AUC for CRIB-II (0.68 ± 0.02) did not significantly differ from that of gestation (0.65 ± 0.02) and BW (0.65 ± 0.02).

CONCLUSION

CRIB-II improved prediction of mortality but did not perform better than gestational age or BW in predicting FD. We would caution clinicians against using the infant's condition at admission to predict long-term outcome.

Financial, vocational, and interpersonal impact of living liver donation

The ability to inform prospective donors of the psychosocial risks of living liver donation is currently limited by the scant empirical literature. The present study was designed to examine donor perceptions of the impact of donation on financial, vocational, and interpersonal life domains and identify demographic and clinical factors related to longer recovery times and greater life interference. A total of 143 donors completed a retrospective questionnaire that included a standardized measure of life interference [Illness Intrusiveness Rating Scale (IIRS)] and additional questions regarding the perceived impact of donation. Donor IIRS scores suggested that donors experience a relatively low level of life interference due to donation [1.60 +/- 0.72, with a possible range of 1 ("not very much" interference) to 7 ("very much" interference)]. However, approximately 1 in 5 donors reported that donating was a significant financial burden. Logistic regression analysis revealed that donors with a psychiatric diagnosis at or prior to donation took longer to return to their self-reported predonation level of functioning (odds ratio = 3.78, P = 0.016). Medical complications were unrelated to self-reported recovery time. Multiple regression analysis revealed 4 independent predictors of greater life interference: less time since donation (b = 0.11, P < 0.001), income lower than CAD$100,000 (b = 0.28, P = 0.038), predonation concerns about the donation process (b = 0.24, P = 0.008), and the perception that the recipient is not caring for the new liver (b = 0.12, P = 0.031). In conclusion, life interference due to living liver donation appears to be relatively low. Donors should be made aware of risk factors for greater life disruptions post-surgery and of the potential financial burden of donation.

Adult right-lobe living liver donors: quality of life, attitudes and predictors of donor outcomes

To refine selection criteria for adult living liver donors and improve donor quality of care, risk factors for poor postdonation health-related quality of life (HRQOL) must be identified. This cross-sectional study examined donors who underwent a right hepatectomy at the University of Toronto between 2000 and 2007 (n = 143), and investigated predictors of (1) physical and mental health postdonation, as well as (2) willingness to participate in the donor process again. Participants completed a standardized HRQOL measure (SF-36) and measures of the pre- and postdonation process. Donor scores on the SF-36 physical and mental health indices were equivalent to, or greater than, population norms. Greater predonation concerns, a psychiatric diagnosis and a graduate degree were associated with lower mental health postdonation whereas older donors reported better mental health. The majority of donors (80%) stated they would donate again but those who perceived that their recipient engaged in risky health behaviors were more hesitant. Prospective donors with risk factors for lower postdonation satisfaction and mental health may require more extensive predonation counseling and postdonation psychosocial follow-up. Risk factors identified in this study should be prospectively evaluated in future research.

Fgf2 is expressed in human and murine embryonic choroid plexus and affects choroid plexus epithelial cell behaviour

Background

Although fibroblast growth factor (Fgf) signalling plays crucial roles in several developing and mature tissues, little information is currently available on expression of Fgf2 during early choroid plexus development and whether Fgf2 directly affects the behaviour of the choroid plexus epithelium (CPe). The purpose of this study was to investigate expression of Fgf2 in rodent and human developing CPe and possible function of Fgf2, using in vitro models. The application of Fgf2 to brain in vivo can affect the whole tissue, making it difficult to assess specific responses of the CPe.

Methods

Expression of Fgf2 was studied by immunohistochemistry in rodent and human embryonic choroid plexus. Effects of Fgf2 on growth, secretion, aggregation and gene expression was investigated using rodent CPe vesicles, a three-dimensional polarized culture model that closely mimics CPe properties in vivo, and rodent CPe monolayer cultures.

Results

Fgf2 was present early in development of the choroid plexus both in mouse and human, suggesting the importance of this ligand in Fgf signalling in the developing choroid plexus. Parallel analysis of Fgf2 expression and cell proliferation during CP development suggests that Fgf2 is not involved in CPe proliferation in vivo. Consistent with this observation is the failure of Fgf2 to increase proliferation in the tri-dimensional vesicle culture model. The CPe however, can respond to Fgf2 treatment, as the diameter of CPe vesicles is significantly increased by treatment with this growth factor. We show that this is due to an increase in cell aggregation during vesicle formation rather than increased secretion into the vesicle lumen. Finally, Fgf2 regulates expression of the CPe-associated transcription factors, Foxj1 and E2f5, whereas transthyretin, a marker of secretory activity, is not affected by Fgf2 treatment.

Conclusion

Fgf2 expression early in the development of both human and rodent choroid plexus, and its ability to modulate behaviour and gene expression in CPe, supports the view that Fgf signalling plays a role in the maintenance of integrity and function of this specialized epithelium, and that this role is conserved between rodents and humans.

Bacterial isolates from equine infections in western Canada (1998-2003)

All bacterial samples of equine origin submitted to the diagnostic laboratory at the Western College of Veterinary Medicine from January 1998 to December 2003 from either "in-clinic" or Field Service cases were accessed (1323 submissions). The most common bacterial isolates from specific presenting signs were identified, along with their in vitro antimicrobial susceptibility patterns. The most common site from which significant bacterial isolates were recovered was the respiratory tract, followed by wounds. Streptococcus zooepidemicus was the most common isolate from most infections, followed by Escherichia coli. Antimicrobial resistance was not common in the isolates and acquired antimicrobial resistance to multiple drugs was rare. The results are compared with previous published studies from other institutions and used to suggest appropriate antimicrobial treatments for equine infections in western Canada.

Do single and partnered women with gynecologic cancer differ in types and intensities of illness- and treatment-related psychosocial concerns? A pilot study

OBJECTIVE

We compared the psychosocial and psychosexual concerns of single and partnered women with gynecologic cancer, since relationship status and psychosocial context are known to affect sexuality, a life domain commonly affected by this cancer.

METHOD

A cross-sectional convenience sample of 49 women (68% response), with ovarian (n=31), endometrial (n=12), and cervical (n=6) cancer, responded to a 72-item self-report Cancer Concerns Questionnaire and additional psychosocial questionnaires.

RESULTS

Single (n=13) and partnered women (n=36) similarly reported prognosis as their highest concern, but single women (26% of the sample) reported that communication with the treatment team, treatment side effects, and prognosis were of greater salience to them than did partnered women. The latter group had greater sexuality and partner relationship concerns.

CONCLUSION

These preliminary findings suggest that relationship status, whether partnered or single, influences current psychosocial concerns among women with gynecologic cancer, despite similar levels of illness- and treatment-related intrusions on important life domains.

The role of GABAA receptor biogenesis, structure and function in epilepsy

Maintaining the correct balance in neuronal activation is of paramount importance to normal brain function. Imbalances due to changes in excitation or inhibition can lead to a variety of disorders ranging from the clinically extreme (e.g. epilepsy) to the more subtle (e.g. anxiety). In the brain, the most common inhibitory synapses are regulated by GABAA (γ-aminobutyric acid type A) receptors, a role commensurate with their importance as therapeutic targets. Remarkably, we still know relatively little about GABAA receptor biogenesis. Receptors are constructed as pentameric ion channels, with α and β subunits being the minimal requirement, and the incorporation of a γ subunit being necessary for benzodiazepine modulation and synaptic targeting. Insights have been provided by the discovery of several specific assembly signals within different GABAA receptor subunits. Moreover, a number of recent studies on GABAA receptor mutations associated with epilepsy have further enhanced our understanding of GABAA receptor biogenesis, structure and function.

Growth of choroid plexus epithelium vesicles in vitro depends on secretory activity

Although a number of models have been used to study choroid plexus epithelium (CPe) function, analysis in physiological conditions of this polarised epithelium which produces the majority of the cerebrospinal fluid (CSF) and is one of the key barriers between blood and CSF in the brain remains challenging. As CPe cells form polarised CPe vesicles when cultured in Matrigel, we have assessed their behaviour and potential use for pharmacological studies. Like CPe cells in vivo, CPe vesicles express transthyretin, E2f5, Fox-j1 and p73, and contain tight junctions, as indicated by ZO-1 expression and electron microscopy analysis. Time-lapse microscopy shows that CPe cells plated in Matrigel are highly migratory and rapidly form homotypic cell aggregates, which then reorganise to form vesicles whose size increases linearly overtime. Neither aggregate nor vesicle size is affected by AraC treatment, though this inhibitor significantly reduces proliferation in CPe monolayers. Increase in size of vesicles, which have reached a growth plateau is observed following addition of fluorescently-labelled CPe cells, which become incorporated into the vesicle walls. Significantly, treatment with secretion inhibitors blocks vesicle formation and their expansion. These results show that secretion, rather than cell division, controls vesicle growth, consistent with low levels of proliferation and thinning of the CPe observed both in growing vesicles and during CPe development. Therefore, changes in vesicle size can be used to evaluate the effect of putative molecules involved in the regulation of secretion.

The psychosocial impact of cervical cancer among affected women and their partners

This study aimed to assess the range and intensity of psychosocial concerns experienced by women with cervical cancer and their male partners. A cross-sectional survey assessed 26 couples where the woman had invasive cervical cancer stage I-IV, up to 2 years posttreatment, using a concerns questionnaire and widely used psychosocial questionnaires. Respondents indicated their concerns about the impact of the disease and treatment as well as general psychosocial impact. Women with cervical cancer and their male partners expressed equal intensities of concern regarding the illness and its treatment, rating sexuality, prognosis, and communication with the treatment team most highly in terms of current concerns. Couples where the patient had a more advanced stage of cancer expressed higher concerns than those with earlier stage disease. Although women with cervical cancer reported more fatigue and illness intrusiveness than their male partners, both experienced disruptions in relationships, intimacy, and instrumental life domains. With increased time posttreatment, concerns differed subtly between affected women and their male partners. Effective psychosocial support for cervical cancer must be provided for both the affected woman and her male partner. Support and information should address the most salient concerns of patients and partners as these evolve over significant clinical milestones.

Progression of the morphogenetic furrow in the Drosophila eye: the roles of Hedgehog, Decapentaplegic and the Raf pathway

During Drosophila eye development, Hedgehog (Hh) protein secreted by maturing photoreceptors directs a wave of differentiation that sweeps anteriorly across the retinal primordium. The crest of this wave is marked by the morphogenetic furrow, a visible indentation that demarcates the boundary between developing photoreceptors located posteriorly and undifferentiated cells located anteriorly. Here, we present evidence that Hh controls progression of the furrow by inducing the expression of two downstream signals. The first signal, Decapentaplegic (Dpp), acts at long range on undifferentiated cells anterior to the furrow, causing them to enter a ‘pre-proneural’ state marked by upregulated expression of the transcription factor Hairy. Acquisition of the pre-proneural state appears essential for all prospective retinal cells to enter the proneural pathway and differentiate as photoreceptors. The second signal, presently unknown, acts at short range and is transduced via activation of the Serine-Threonine kinase Raf. Activation of Raf is both necessary and sufficient to cause pre-proneural cells to become proneural, a transition marked by downregulation of Hairy and upregulation of the proneural activator, Atonal (Ato), which initiates differentiation of the R8 photoreceptor. The R8 photoreceptor then organizes the recruitment of the remaining photoreceptors (R1-R7) through additional rounds of Raf activation in neighboring pre-proneural cells. Finally, we show that Dpp signaling is not essential for establishing either the pre-proneural or proneural states, or for progression of the furrow. Instead, Dpp signaling appears to increase the rate of furrow progression by accelerating the transition to the pre-proneural state. In the abnormal situation in which Dpp signaling is blocked, Hh signaling can induce undifferentiated cells to become pre-proneural but does so less efficiently than Dpp, resulting in a retarded rate of furrow progression and the formation of a rudimentary eye.

Different levels of Ras activity can specify distinct transcriptional and morphological consequences in early Drosophila embryos

The terminal portions of the Drosophila body pattern are specified by the localized activity of the receptor tyrosine kinase Torso (Tor) at each pole of the early embryo. Tor activity elicits the transcription of two ‘gap’ genes, tailless (tll) and huckebein (hkb), in overlapping but distinct domains by stimulating the Ras signal transduction pathway. Here, we show that quantitative variations in the level of Ras activity can specify qualitatively distinct transcriptional and morphological responses. Low levels of Ras activity at the posterior pole direct tll but not hkb transcription; higher levels drive transcription of both genes. Correspondingly, low levels of Ras activity specify a limited subset of posterior terminal structures, whereas higher levels specify a larger subset. However, we also show that the response to Ras activity is not uniform along the body. Instead, levels of Ras activity which suffice to drive tll and hkb transcription at the posterior pole fail to drive their expression in more central portions of the body, apparently due to repression by other gap gene products. We conclude that tll and hkb transcription, as well as the terminal structures, are specified by two inputs: a gradient of Ras activity which emanates from the pole, and the opposing influence of more centrally deployed gap genes which repress the response to Ras.