Portfolios in practice: Developing advancing practice within a musculoskeletal competency-based model

INTRODUCTION

The development of professional portfolios and the relevance of this within professional practice, competency and capability is gaining significant credibility in line with professional requirements. Nursing and medicine in terms of historical perspectives have long held the need for clinicians to maintain a portfolio for professional validation, whilst in other professional groups it is a requirement of registration. The allied health professionals, physiotherapy and ultimately musculoskeletal practice within this context are rapidly developing advancing and consultant practice. This professional development further requires appropriate verification and validation of practice, and achieving this can be through formal and non-formal routes.

PURPOSE

This paper looks to explore this and give direction to professionals developing portfolios whilst placing the requirements in context to contemporary practice in the U.K. Universities, professional bodies and special interest groups are now aligning in the need to support practice in a multi-format way, that moves away from traditional methods of evaluation into more diverse models of competency-based assessment.

IMPLICATIONS

With improvement in technology, the development of national frameworks and standards, portfolios in practice although commonly considered as standard practice will be a requirement not only of registration but as a criteria of maintaining status, career development and expansion of roles.

BACKGROUND

Musculoskeletal (MSK) physiotherapy in the U.K. has moved forward significantly in the last 20 years. Sitting within a clinical reasoned framework, the introduction of additional skills such is image requesting, injection therapies, and non-medical prescribing has further underpinned the advanced practice agenda (Langridge et al., 2015). While these advancements in practice are driving the profession forward, challenges remain in providing the workforce with a clear process of career development. Alongside developing professional pathways methods of evidencing advanced knowledge and skills acquired outside formal routes are required to support practitioners' career pathway into advancing practice.

15 FRAILTY AND ADVERSE OUTCOMES IN HIP FRACTURE PATIENTS

Background

Frailty is highly prevalent in older hip fracture patients, conferring greater risk of poorer outcomes including increased Length of Stay (LOS), Nursing Home (NH) placement and mortality

Methods

This prospective observational study took place in a large university hospital with a daily trauma list and an established orthogeriatric service. We compared 3 different screening tools; Rockwood Clinical Frailty Scale (CFS), Zuckerman’s Functional Recovery Score (FRS) and New Mobility Score (NMS) and their ability to predict outcomes in hip fracture patients. Participants included all hip fracture patients (>/= 60 years old) admitted to the orthopaedic ward from 2016-2018. Scores were assigned by an ortho-geriatrician and were analysed at admission and at 1 year.

Results

Increasing frailty scores were associated with increased mortality, LOS and NH admission rates. Those with a CFS of 4-6 had an increased risk of mortality compared to those with a CFS of 1-3 (OR:3.81, CI 2.15-6.76). Those with a CFS of 7-9 demonstrated increased risk of mortality compared to those without frailty (OR: 8.75, CI 4.58-16.72). Patients with mild-moderate frailty (CFS 4-6) were 5 times more likely to require NH at 1-year (OR 5.09, CI 3.03-8.56) and those with severe frailty (CFS 7-9) were 7 times more likely to be in a NH at 1-year (OR 7.03, CI 3.82-12.94). The moderate frailty group had an inpatient stay 16 days longer than the non-frail group and the severe frailty group, 26 days longer than the non-frail group. Results were similar for FRS and NMS and when adjusted for age. Comparing the discrimination of the different measures for predicting survival, analysis of receiver operating characteristic curves revealed - 0.73 (CFS), 0.72 (NMS) 0.74 (FRS). Interestingly, the mortality rate for men was 32% compared to 21% for females (OR: 1.75 p=0.005).

Conclusion

Assessing frailty with a standardised protocol could reliably estimate the risk of adverse outcomes in hip fracture patients.

Acute postoperative pain management

Background

Acute postoperative pain is common. Nearly 20 per cent of patients experience severe pain in the first 24 h after surgery, a figure that has remained largely unchanged in the past 30 years. This review aims to present key considerations for postoperative pain management.

Methods

A narrative review of postoperative pain strategies was undertaken. Searches of the Cochrane Library, PubMed and Google Scholar databases were performed using the terms postoperative care, psychological factor, pain management, acute pain service, analgesia, acute pain and pain assessment.

Results

Information on service provision, preoperative planning, pain assessment, and pharmacological and non-pharmacological strategies relevant to acute postoperative pain management in adults is presented, with a focus on enhanced recovery after surgery pathways.

Conclusion

Adequate perioperative pain management is integral to patient care and outcomes. Each of the biological, psychological and social dimensions of the pain experience should be considered and understood in order to provide optimum pain management in the postoperative setting.

Perioperative and early rehabilitation outcomes following osseointegration in UK military amputees

Introduction

This paper examines the pain management, from surgery to specialist rehabilitation, of the first seven military transfemoral amputee patients treated in the UK with femoral osseointegration. All the patients had sustained complex ballistic injuries on the battlefield. The patients were characterised by long-standing problems with functional rehabilitation due to limitations with conventional prostheses, including stump soft tissue issues and impaired biomechanics.

Methods

A prospective service investigation was undertaken to evaluate the effectiveness of the pain management of patients undergoing osseointegration. Data were collected by daily direct patient contact, supplemented by a focused review of perioperative and rehabilitation case notes. Physiological and medication details were recorded with specific reference to systemic and regional analgesia and the impact of postoperative complications, including infection and accidental injury.

Results

Seven patients underwent femoral osseointegration and were followed up for a period of up to 3 years following surgery. The perioperative recovery was associated with significant escalation of analgesic requirements. Postoperative systemic inflammatory response syndrome was identified in six patients, with wound infection persisting in some cases into the rehabilitation phase. Three patients suffered femoral fractures following accidental injuries secondary to increased mobilisation following surgery.

Conclusions

Successful surgical outcomes were achieved in a difficult patient cohort disadvantaged by previously restricted functional recovery from complex injuries. The importance of supporting the operative and recovery phases with a multidisciplinary pain service is emphasised. We offer this data and the lessons learnt to assist clinicians contemplating the establishment and service development of osseointegration services.

(ICORG 05-03): prospective randomized non-inferiority phase III trial comparing two radiation schedules in malignant spinal cord compression (not proceeding with surgical decompression); the quality of life analysis

BACKGROUND

The optimal primary external beam radiation therapy (EBRT) radiation schedule for malignant epidural spinal cord compression (MSCC) remains to be determined. The ICORG 05-03 trial assessed if a 10 Gy single fraction radiation schedule was not inferior to one with 20 Gray (Gy) in five daily fractions, in terms of functional motor outcome, for the treatment of MSCC in patients not proceeding with surgical decompression. This article reports on two of the secondary endpoints, Quality of life (QoL), assessed according to the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30 (QLQ-C30) version 3.0 (EORTC Data Center, Brussels, Belgium) and pain control assessed using a visual analog scale.

METHODS

A randomized, parallel group, multicenter phase III trial was conducted by Cancer Trials Ireland (formerly All-Ireland Cooperative Oncology Research Group, ICORG), across five hospital sites in Ireland and Northern Ireland. Patients were randomized to 10 Gy single fraction of EBRT or 20 Gy in five fractions in a 1:1 ratio. Patients with baseline and 5-week follow up QoL data are included in this analysis.

FINDINGS

From 2006 to 2014, 112 eligible patients were enrolled for whom 57 were evaluated for this secondary analysis. After adjusting for pre-intervention scores, there was no statistically significant difference in post-treatment Summary scores (excl. FI and QL), or pain scores between the two RT schedules at 5 weeks and 3 months following EBRT. There was a statistically significant relationship between the pretreatment and post-treatment Summary scores (p =  .002) but not between the pre-treatment and post-treatment pain scores.

INTERPRETATION

Primary radiotherapy for the treatment of MSCC significantly improves QoL in patients not proceeding with surgical decompression. After adjusting for pre-intervention scores, there was no statistically significant difference between a 10 Gy single fraction radiation schedule and one with 20 Gy in five daily fractions on post-treatment QoL Summary scores. For most patients, an effective treatment with low burden would be desirable. A single fraction schedule should be considered for this group of patients.

Neuropathic pain treatment and research: experiences from the United Kingdom mission to Afghanistan and future prospects

The Defence Medical Services (DMS) of the United Kingdom (UK) assumed command of the Role 3 Medical Treatment Facility field hospital during Operation HERRICK in Afghanistan from April 2006 until the final drawdown in November 2014. The signature injury sustained by coalition personnel during this period was traumatic amputation from improvised explosive devices. Many patients who had suffered extensive tissue damage experienced both nociceptive and neuropathic pain (NeuP). This presented as a heterogeneous collection of symptoms that are resistant to treatment. This paper discusses the relationship of NeuP in the context of ballistic injury, drawing in particular on clinical experience from the UK mission to Afghanistan, Operation HERRICK. The role of this paper is to describe the difficulties of assessment, treatment and research of NeuP and make recommendations for future progress within the DMS.

Adjuvant Radiotherapy Use by US Radiation Oncologists After Radical Cystectomy for Muscle-invasive Bladder Cancer

AIMS

Historic trials suggested significant toxicity with adjuvant radiotherapy (ART) after radical cystectomy for muscle-invasive bladder cancer (MIBC). However, recent trials have found improved locoregional control and the 2016 National Comprehensive Cancer Network (NCCN) guidelines recommend ART consideration for select patients at high risk of local recurrence. ART practice patterns among US radiation oncologists are unknown and we carried out a survey to explore current trends.

MATERIALS AND METHODS

We conducted a survey of US radiation oncologists regarding the management of patients with cT2-3N0M0 transitional cell MIBC. Responses were reported using descriptive statistics. Chi-square and univariate logistic regression of clinical and demographic covariates were conducted, followed by multivariable logistic regression analysis to identify factors predicting for ART use.

RESULTS

In total, 277 radiation oncologists completed our survey. Nearly half (46%) have used ART for MIBC at least once in the past. In ART users, indications for ART include gross residual disease (93%), positive margins (92%), pathological nodal involvement (64%), pT3 or T4 disease (46%), lymphovascular invasion (16%) and high-grade disease (13%). On univariate logistic regression, ART use was associated with the number of years in practice (P=0.04), pre-cystectomy radiation oncology consultation (P=0.004), primarily treating MIBC patients fit for cystectomy (P=0.01) and intensity-modulated radiotherapy use (P=0.01). On multivariable logistic regression analysis, routine pre-cystectomy radiation oncology consultation (odds ratio 1.91, 95% confidence interval 1.04-3.51; P=0.04) and intensity-modulated radiotherapy use (odds ratio 2.77, 95% confidence interval 1.48-5.22; P=0.002) remained associated with ART use.

CONCLUSIONS

ART use is controversial in bladder cancer, yet unexpectedly has commonly been used among US radiation oncologists treating patients with MIBC after radical cystectomy. NRG-GU001 was a randomised trial in the US randomizing patients with high-risk pathological findings for observation or ART after cystectomy. However, due to poor accrual it recently closed and thus it will be up to other international trials to clarify the role of ART and identify patients benefiting form this adjuvant therapy.

Therapeutic effect of flax-based diets on fatty liver in aged laying hens

This study examined the ability of flax-based ingredients to attenuate nonalcoholic fatty liver disease ( NAFLD: ) in aged laying hens-a novel and more physiologically relevant model of human disease. Our results showed only hens supplemented with whole flaxseed ( WFX: ) reduced steatosis and hepatocellular ballooning. Serum AST was also reduced in hens provided WFX and defatted flaxseed meal ( DFM: ). Hepatic ω-3 PUFA enrichment was improved with supplementation of WFX, DFM, and flaxseed oil ( FXO: ). However, this effect was more evident in the WFX group. In contrast, transcript abundance of genes linked to NAFLD were predominantly modified with FXO supplementation. Taken together, our data indicate a potential synergistic relationship between the fatty acid and lignan content in flaxseed which attenuated the progression of NAFLD in aged laying hens. Although more research is necessary, these findings demonstrate the potential use of whole flaxseed for the treatment and prevention of NAFLD in humans.

Effect of colored lenses on muscular performance

AIM

The effect of color on physiological parameters appears well documented. However, methodological weaknesses and limitations to practical application suggest it to be substantially under researched with regard to physical performance. The aim of this study was to consider the effects of red, blue and clear (control) colored lens glasses on a muscular endurance task.

METHODS

Fifteen healthy males (21±1.34 years) were instructed to perform repetitions to failure using their predetermined 25 repetition maximum (RM) on a seated leg press. Participants completed three randomised trials exposed to blue, red and clear lenses.

RESULTS

A repeated measure ANOVA identified a significant difference in the amount of repetitions performed between the three conditions. A pairwise comparison revealed significantly greater repetitions for the blue lens condition compared to clear lenses (P=0.008). From the data an effect size (ES) of 0.76 was calculated for blue lensed glasses. The red lens condition showed no significant variation from clear lenses in repetitions performed.

CONCLUSION

The findings of this research suggest that exposure to the color blue improves performance of a muscular endurance based task. Such a simple and inexpensive performance enhancement warrants further investigation to explore different exercise modalities as well as effects of different colored lenses, and the mechanisms as to how color affects performance.

Application of machine learning methodology for PET-based definition of lung cancer

We applied a learning methodology framework to assist in the threshold-based segmentation of non-small-cell lung cancer (nsclc) tumours in positron-emission tomography–computed tomography (pet–ct) imaging for use in radiotherapy planning. Gated and standard free-breathing studies of two patients were independently analysed (four studies in total). Each study had a pet–ct and a treatment-planning ct image. The reference gross tumour volume (gtv) was identified by two experienced radiation oncologists who also determined reference standardized uptake value (suv) thresholds that most closely approximated the gtv contour on each slice. A set of uptake distribution-related attributes was calculated for each pet slice. A machine learning algorithm was trained on a subset of the pet slices to cope with slice-to-slice variation in the optimal suv threshold: that is, to predict the most appropriate suv threshold from the calculated attributes for each slice. The algorithm’s performance was evaluated using the remainder of the pet slices. A high degree of geometric similarity was achieved between the areas outlined by the predicted and the reference suv thresholds (Jaccard index exceeding 0.82). No significant difference was found between the gated and the free-breathing results in the same patient. In this preliminary work, we demonstrated the potential applicability of a machine learning methodology as an auxiliary tool for radiation treatment planning in nsclc.

232. Developmentally regulated activin A signal transduction by Sertoli cells is required for normal mouse testis development

Activin A, a TGF-β superfamily ligand, is critical for normal mouse testis development and quantitatively normal sperm production. Testicular activin production changes during development, being substantially higher in the immature testis relative to the adult [1, 2]. Activin influences the Sertoli cell, the nurse cell to developing sperm, enhancing proliferation during its immature phase, but not following terminal differentiation [3]. In the Inha−/− mouse, chronic excessive activin production results in Sertoli cell-derived tumours [4] whereas reduced activin bioactivity, in the InhbaBK/BK mouse, delays fertility [5]. Activin signals are transduced by the phosphorylation and nuclear accumulation of the transcription factors SMAD2 and SMAD3. By comparing activin signal transduction in immature v. terminally differentiated Sertoli cells, using quantitative confocal microscopy and western blot analysis of total and phosphorylated SMAD2 and SMAD3, we discovered that mouse Sertoli cells exhibit developmentally regulated activin responses. Activin induces nuclear accumulation of SMAD3, but not SMAD2, in immature cells, although both proteins are phosphorylated. In contrast, terminally differentiated cells exhibit nuclear accumulation of both SMAD2 and SMAD3. We observed that this shift coincides with decreased SMAD3 production at puberty and changes in FSH-induced Smad transcription, which favours Smad3 in immature cells but promotes Smad2 synthesis in terminally differentiated cells. Furthermore, whereas removal of SMAD3 from the Inha−/− mouse rescues the tumour phenotype [6], we demonstrated that insufficient SMAD3 production impairs testis growth. We hypothesised that this developmentally regulated SMAD utilisation drives specific transcriptional outcomes. Using microarray and quantitative PCR, we identified novel activin target genes displaying developmental stage-specific expression patterns coinciding with differential SMAD usage, including Gja1 and Serpina5 which are required for male fertility. These mRNAs are also modulated in vivo, increased 1.5–2 fold in Inha−/− testes and decreased by half in InhbaBK/BK testes, confirming that normal testis development requires carefully regulated activin production and responsiveness. (1) Buzzard J et al. 2004. Endocrinology 145(7): 3532–3541 (2) Barakat et al. 2008. Reproduction 2008 Epub ahead of print (3) Boitani C et al. 1995. Endocrinology 136(12): 4538–4544 (4) Matzuk M et al. 1992. Nature 360: 313–319 (5) Brown C et al. 2000. Nature Genetics 25(4): 453–457 (6) Li Q et al. 2007. Molecular Endocrinology 21(10: 2472–2486

Examination of reproductive aging milestones among women who carry the FMR1 premutation

BACKGROUND

The fragile X premutation is characterized by a large CGG repeat track (55-199 repeats) in the 5' UTR of the FMR1 gene. This X-linked mutation leads to an increased risk for premature ovarian failure; interestingly, the association of repeat size with risk is non-linear. We hypothesize that the premutation-associated ovarian insufficiency is due to a diminished oocyte pool and examined reproductive aging milestones by repeat size group to determine if the same non-linear association is observed.

METHODS

We analyzed cross-sectional reproductive history questionnaire data from 948 women with a wide range of repeat sizes.

RESULTS

We have confirmed the non-linear relationship among premutation carriers for ovarian insufficiency. The mid-range repeat size group (80-100 repeats), not the highest group, had an increased risk for: altered cycle traits (shortened cycle length, irregular cycles and skipped cycles), subfertility and dizygotic twinning. Smoking, a modifiable risk, decreased the reproductive lifespan of women with the premutation by about 1 year, similar to its effect on non-carriers. As expected, premutation carriers were found to be at an increased risk for osteoporosis.

CONCLUSIONS

Possible molecular mechanisms to explain the non-linear repeat size risk for ovarian insufficiency are discussed.

Examination of reproductive aging milestones among women who carry the FMR1 premutation

BACKGROUND

The fragile X premutation is characterized by a large CGG repeat track (55-199 repeats) in the 5' UTR of the FMR1 gene. This X-linked mutation leads to an increased risk for premature ovarian failure; interestingly, the association of repeat size with risk is non-linear. We hypothesize that the premutation-associated ovarian insufficiency is due to a diminished oocyte pool and examined reproductive aging milestones by repeat size group to determine if the same non-linear association is observed.

METHODS

We analyzed cross-sectional reproductive history questionnaire data from 948 women with a wide range of repeat sizes.

RESULTS

We have confirmed the non-linear relationship among premutation carriers for ovarian insufficiency. The mid-range repeat size group (80-100 repeats), not the highest group, had an increased risk for: altered cycle traits (shortened cycle length, irregular cycles and skipped cycles), subfertility and dizygotic twinning. Smoking, a modifiable risk, decreased the reproductive lifespan of women with the premutation by about 1 year, similar to its effect on non-carriers. As expected, premutation carriers were found to be at an increased risk for osteoporosis.

CONCLUSIONS

Possible molecular mechanisms to explain the non-linear repeat size risk for ovarian insufficiency are discussed.

Ghrelin increases food intake in obese as well as lean subjects

OBJECTIVE

To investigate whether effects on food intake are seen in obese subjects receiving exogenous administration of ghrelin.

DESIGN

Randomised, double-blind, placebo-controlled study of intravenous ghrelin at doses 1 pmol/kg/min and 5 pmol/kg/min.

SUBJECTS

In all, 12 healthy lean subjects (mean body mass index (BMI) 20.5+/-0.17 kg/m(2)) and 12 healthy overweight and obese subjects (mean BMI 31.9+/-1.02 kg/m(2)).

MEASUREMENTS

Food intake, appetite and palatability of food, ghrelin and other obesity-related hormones, growth hormone.

RESULTS

Low-dose infusion of ghrelin increased ad libitum energy intake at a buffet meal in the obese group only (mean increase 36.6+/-9.4%, P<0.01.) High-dose ghrelin infusion increased energy intake in both groups (mean increase 20.1+/-10.6% in the lean and 70.1+/-15.5% in the obese, P<0.01 in both cases.) Ghrelin infusion increased palatability of food in the obese group.

CONCLUSION

Ghrelin increases food intake in obese as well as lean subjects. Obese people are sensitive to the appetite-stimulating effects of ghrelin and inhibition of circulating ghrelin may be a useful therapeutic target in the treatment of obesity.

The influence of ridge migration on the magmatic segmentation of mid-ocean ridges

The Earth's mid-ocean ridges display systematic changes in depth and shape, which subdivide the ridges into discrete spreading segments bounded by transform faults and smaller non-transform offsets of the axis. These morphological changes have been attributed to spatial variations in the supply of magma from the mantle, although the origin of the variations is poorly understood. Here we show that magmatic segmentation of ridges with fast and intermediate spreading rates is directly related to the migration velocity of the spreading axis over the mantle. For over 9,500 km of mid-ocean ridge examined, leading ridge segments in the 'hotspot' reference frame coincide with the shallow magmatically robust segments across 86 per cent of all transform faults and 73 per cent of all second-order discontinuities. We attribute this relationship to asymmetric mantle upwelling and melt production due to ridge migration, with focusing of melt towards ridge segments across discontinuities. The model is consistent with variations in crustal structure across discontinuities of the East Pacific Rise, and may explain variations in depth of melting and the distribution of enriched lavas.

Effect of apolipoprotein E genotype on hippocampal volume loss in aging healthy women

OBJECTIVE

To determine whether the presence of a single epsilon4 allele of the APOE gene is associated with an increased rate of hippocampal volume loss or decline in cognition in healthy women in their sixth decade of life.

METHODS

Nine APOE-epsilon4 allele-negative (mean age +/- SD, 60.6 +/- 10.2 years) and 16 APOE-epsilon4 allele-positive (mean age +/- SD, 55.1 +/- 6.0 years) healthy women underwent neurocognitive testing and MRI at the time of entry into the study (baseline) and 2 years later. Neurocognitive testing consisted of the Buschke-Fuld Free Recall, verbal fluency tests, the Rey Figure Test, the Wechsler Memory Scale-Revised, and the Wechsler Adult Intelligence Survey-Revised Block Design. Hippocampal volume determinations were based on manual outlining of sagittal slices aided by axial, coronal, and three-dimensional views of high-resolution 124-slice whole-brain scans; the scans were obtained with a 1.5-tesla scanner using a T1-weighted three-dimensional gradient echo sequence with RF spoiling (TR/TE/flip angle, 24 msec/3 msec/30 degrees ).

RESULTS

The percent change in hippocampal volume per year was greater in the APOE-epsilon4 allele-positive group (mean +/- SD, 2.32 +/- 1.75%) than in the APOE-epsilon4 allele-negative group (mean +/- SD, 0.77 +/- 1.02%; t = 2.41; p < 0.03, two-tailed test). There were no significant differences between the two groups in terms of any of the cognitive measures, and hippocampal volume loss was not correlated with changes in any of the above-mentioned cognitive measures.

CONCLUSIONS

The presence of a single APOE-epsilon4 allele is associated with an increased rate of hippocampal volume loss in healthy women in their sixth decade of life that is not related to any detectable memory changes.

Orexin A immunoreactivity and preproorexin mRNA in the brain of Zucker and WKY rats

The primary role of the orexins was originally believed to be appetite regulation, but is now believed to be the regulation of sleep, arousal and locomotor activity. Orexin A immunoreactivity (orexin A-IR) and prepro-orexin mRNA were measured in the CNS of obese and lean Zucker rats. There were no differences in orexin A-IR or prepro-orexin mRNA levels between obese and lean Zucker rats. The orexins are therefore unlikely to be important in this model of obesity. Levels of orexin A-IR and prepro-orexin mRNA were measured in the CNS of Wistar-Kyoto (WKY) rats, which are hypoactive and have abnormal sleep architecture. Compared to Wistar rats, WKY rats had significantly lower orexin A-IR (with differences of up to 100% in some brain regions) and prepro-orexin mRNA levels. These observations suggest that the sleep and activity phenotype of the WKY strain may be related to orexin deficiency and that this strain may be a useful model of partial orexin deficiency.

Overlapping roles for granulocyte-macrophage colony-stimulating factor and interleukin-3 in eosinophil homeostasis and contact hypersensitivity

Studies of mice rendered deficient in granulocyte-macrophage colony-stimulating factor (GM-CSF) or interleukin-3 (IL-3) have established unique roles for these cytokines in pulmonary homeostasis, resistance to infection, and antigen-specific T- and B-cell responses. In addition to these distinctive properties, however, GM-CSF and IL-3 also stimulate the development and activation of hematopoietic cells in many similar ways, raising the possibility that each factor might partially compensate for the other's absence in singly deficient mice. To test whether endogenous GM-CSF and IL-3 mediate redundant functions in vivo, we generated mice lacking both cytokines through sequential gene targeting experiments in embryonic stem (ES) cells. Surprisingly, doubly deficient animals, but not single knockouts, showed increased numbers of circulating eosinophils. Doubly deficient mice, moreover, developed weaker contact hypersensitivity reactions to haptens applied epicutaneously than mice deficient in either factor alone. Together, these findings delineate overlapping roles for GM-CSF and IL-3 in hematopoiesis and immunity. (Blood. 2001;97:922-928)

Gdf11 is a negative regulator of chondrogenesis and myogenesis in the developing chick limb

GDF11, a new member of the TGF-beta gene superfamily, regulates anterior/posterior patterning in the axial skeleton during mouse embryogenesis. Gdf11 null mice display skeletal abnormalities that appear to represent anterior homeotic transformations of vertebrae consistent with high levels of Gdf11 expression in the primitive streak, presomitic mesoderm, and tail bud. However, despite strong Gdf11 expression in the limb throughout development, this structure does not appear to be affected in the knockout mice. In order to understand this dichotomy of Gdf11 expression versus Gdf11 function, we identified the chicken Gdf11 gene and studied its role during limb formation. In the early limb bud, Gdf11 transcripts are detected in the subectodermal mesoderm at the distal tip, in a region overlapping the progress zone. At these stages, Gdf11 is excluded from the central core mesenchyme where precartilaginous condensations will form. Later in development, Gdf11 continues to be expressed in the distal most mesenchyme and can also be detected more proximally, in between the forming skeletal elements. When beads incubated in GDF11 protein were implanted into the early wing bud, GDF11 caused severe truncations of the limb that affected both the cartilage elements and the muscle. Limb shortening appeared to be the result of an inhibition of chondrogenesis and myogenesis and using an in vitro micromass assay, we confirmed the negative effects of GDF11 on both myogenic and chondrogenic cell differentiation. Analysis of molecular markers of skeletal patterning revealed that GDF11 induced ectopic expression of Hoxd-11 and Hoxd-13, but not of Hoxa-11, Hoxa-13, or the Msx genes. These data suggest that GDF11 may be involved in controlling the late distal expression of the Hoxd genes during limb development and that misregulation of these Hox genes by excess GDF11 may cause some of the observed alterations in skeletal element shape. In addition, GDF11 induced the expression of its own antagonist follistatin, indicating that the activity of GFD11 may be limited by a negative feedback mechanism. The data from our studies in the chick suggest that Gdf11 plays a role in the formation and development of the avian limb skeleton.

Altered fetal pituitary-adrenal function in the ovine fetus treated with RU486 and meloxicam, an inhibitor of prostaglandin synthase-II

Term and preterm labor are associated with increased fetal hypothalamic-pituitary-adrenal (HPA) activation and synthesis of prostaglandins (PGs) generated through the increased expression of prostaglandin H synthase-II (PGHS-II) in the placenta. Inhibition of PGHS-II has been advocated as a means of producing uterine tocolysis, but the effects of such treatment on fetal endocrine functions have not been thoroughly examined. Because PGE(2) is known to activate the fetal HPA axis, we hypothesized that administration of meloxicam, a PGHS-II inhibitor, to sheep in induced labor would suppress fetal HPA function. Chronically catheterized pregnant ewes were treated with RU486, a progesterone receptor antagonist, to produce active labor, and then treated with either high-maintenance-dose meloxicam, graded-maintenance-dose meloxicam, or a saline infusion. Maternal uterine contraction frequency increased 24 h after the RU486 injection and the animals were in active labor by 48 +/- 4 h. RU486 injection led to increased concentrations of PGE(2), ACTH, and cortisol in the fetal circulation, and increased concentrations of 13,14 dihydro 15-ketoprostaglandin F(2 alpha) (PGFM) in the maternal circulation. Uterine activity was inhibited within 12 h of beginning meloxicam infusion at both infusion regimes. During meloxicam infusion there were significant decreases in fetal plasma PGE(2), ACTH, and cortisol concentrations, and PGFM concentrations in maternal plasma. In control animals, frequency of uterine contractions, maternal plasma PGFM, fetal plasma PGE(2), ACTH, and cortisol concentrations increased after RU486 administration, and continued to rise during saline infusion until delivery occurred. We conclude that RU486-provoked labor in sheep is associated with activation of fetal HPA function, and that this is attenuated during meloxicam treatment to a level considered compatible with pregnancy maintenance.

Unarmed, tumor-specific monoclonal antibody effectively treats brain tumors

The epidermal growth factor receptor (EGFR) is often amplified and rearranged structurally in tumors of the brain, breast, lung, and ovary. The most common mutation, EGFRvIII, is characterized by an in-frame deletion of 801 base pairs, resulting in the generation of a novel tumor-specific epitope at the fusion junction. A murine homologue of the human EGFRvIII mutation was created, and an IgG2a murine mAb, Y10, was generated that recognizes the human and murine equivalents of this tumor-specific antigen. In vitro, Y10 was found to inhibit DNA synthesis and cellular proliferation and to induce autonomous, complement-mediated, and antibody-dependent cell-mediated cytotoxicity. Systemic treatment with i.p. Y10 of s.c. B16 melanomas transfected to express stably the murine EGFRvIII led to long-term survival in all mice treated (n = 20; P < 0.001). Similar therapy with i.p. Y10 failed to increase median survival of mice with EGFRvIII-expressing B16 melanomas in the brain; however, treatment with a single intratumoral injection of Y10 increased median survival by an average 286%, with 26% long-term survivors (n = 117; P < 0.001). The mechanism of action of Y10 in vivo was shown to be independent of complement, granulocytes, natural killer cells, and T lymphocytes through in vivo complement and cell subset depletions. Treatment with Y10 in Fc receptor knockout mice demonstrated the mechanism of Y10 to be Fc receptor-dependent. These data indicate that an unarmed, tumor-specific mAb may be an effective immunotherapy against human tumors and potentially other pathologic processes in the "immunologically privileged" central nervous system.

Cathepsin S required for normal MHC class II peptide loading and germinal center development

Major histocompatibility complex (MHC) class II molecules acquire antigenic peptides after degradation of the invariant chain (Ii), an MHC class II-associated protein that otherwise blocks peptide binding. Antigen-presenting cells of mice that lack the protease cathepsin S fail to process Ii beyond a 10 kDa fragment, resulting in delayed peptide loading and accumulation of cell surface MHC class II/10 kDa Ii complexes. Although cathepsin S-deficient mice have normal numbers of B and T cells and normal IgE responses, they show markedly impaired antibody class switching to IgG2a and IgG3. These results indicate cathepsin S is a major Ii-processing enzyme in splenocytes and dendritic cells. Its role in humoral immunity critically depends on how antigens access the immune system.

Hypsographic demography: the distribution of human population by altitude

The global distribution of the human population by elevation is quantified here. As of 1994, an estimated 1.88 x 10(9) people, or 33. 5% of the world's population, lived within 100 vertical meters of sea level, but only 15.6% of all inhabited land lies below 100 m elevation. The median person lived at an elevation of 194 m above sea level. Numbers of people decreased faster than exponentially with increasing elevation. The integrated population density (IPD, the number of people divided by the land area) within 100 vertical meters of sea level was significantly larger than that of any other range of elevations and represented far more people. A significant percentage of the low-elevation population lived at moderate population densities rather than at the highest densities of central large cities. Assessments of coastal hazards that focus only on large cities may substantially underestimate the number of people who could be affected.

Involvement of interleukin-3 in delayed-type hypersensitivity

The in vivo functions of interleukin-3 (IL-3) were investigated by generating IL-3-deficient mice. Although hematopoiesis was unimpaired in homozygous mutant animals, contact hypersensitivity reactions were compromised. IL-3 was required for efficient priming of hapten-specific contact hypersensitivity responses, but was dispensable for T-cell-dependent sensitization to tumor cells. These findings reveal a critical role for IL-3 in some forms of delayed-type hypersensitivity.

Leptin interacts with glucagon-like peptide-1 neurons to reduce food intake and body weight in rodents

The adipose tissue hormone, leptin, and the neuropeptide glucagon-like peptide-1 (7-36) amide (GLP-1) both reduce food intake and body weight in rodents. Using dual in situ hybridization, long isoform leptin receptor (OB-Rb) was localized to GLP-1 neurons originating in the nucleus of the solitary tract. ICV injection of the specific GLP-1 receptor antagonist, exendin(9-39), at the onset of dark phase, did not affect feeding in saline pre-treated controls, but blocked the reduction in food intake and body weight of leptin pre-treated rats. These findings suggest that GLP-1 neurons are a potential target for leptin in its control of feeding.