Describing the resource utilisation and costs associated withvertebral fractures: the Build Better Bones with Exercise (B3E) Pilot Trial

This analysis examined costs/resources of 141 women with vertebral fractures, randomised to a home exercise programme or control group. Total, mean costs and the incremental cost-effectiveness ratio (ICER) were calculated. Quality of life was collected. Cost drivers were caregiver time, medications and adverse events (AEs). Results show adding an exercise programme may reduce the risk of AEs.

INTRODUCTION

This exploratory economic analysis examined the health resource utilisation and costs experienced by women with vertebral fractures, and explored the effects of home exercise on those costs.

METHODS

Women ≥ 65 years with one or more X-ray-confirmed vertebral fractures were randomised 1:1 to a 12-month home exercise programme or equal attention control group. Clinical and health system resources were collected during monthly phone calls and daily diaries completed by participants. Intervention costs were included. Unit costs were applied to health system resources. Quality of life (QoL) information was collected via EQ-5D-5L at baseline, 6 and 12 months.

RESULTS

One hundred and forty-one women were randomised. Overall total costs (CAD 2018) were $664,923 (intervention) and $614,033 (control), respectively. The top three cost drivers were caregiver time ($250,269 and $240,811), medications ($151,000 and $122,145) and AEs ($58,807 and $71,981). The mean cost per intervention participant of $9365 ± $9988 was higher compared with the mean cost per control participant of $8772 ± $9718. The mean EQ-5D index score was higher for the intervention participants (0.81 ± 0.11) compared with that of controls (0.79 ± 0.13). The differences in quality-adjusted life year (QALY) (0.02) and mean cost ($593) were used to calculate the ICER of $29,650.

CONCLUSIONS

Women with osteoporosis with a previous fracture experience a number of resources and associated costs that impact their care and quality of life. Caregiver time, medications and AEs are the biggest cost drivers for this population. The next steps would be to expand this feasibility study with more participants, longer-term follow-up and more regional variability.

Obstetric admissions to intensive care units in Australia and New Zealand: a registry-based cohort study

OBJECTIVE

Describe the epidemiology of obstetric patients admitted to an Intensive Care Unit (ICU).

DESIGN

Registry-based cohort study.

SETTING

One hundred and eighty-three ICUs in Australia and New Zealand.

POPULATION

Women aged 15-49 years, admitted to ICU between 2008 and 2017, classified as pregnant, postpartum or with an obstetric-related diagnosis.

METHODS

Data were extracted from the Australia and New Zealand Intensive Care Society (ANZICS) Adult Patient Database and national agencies.

MAIN OUTCOME MEASURES

Incidence of ICU admission, cohort characteristics, maternal outcomes and changes over time.

RESULTS

The cohort comprised 16 063 patients. The annual number of obstetric ICU admissions increased, whereas their proportion of total ICU admissions (1.3%) did not change (odds ratio 1.02, 95% CI 0.99-1.04, P = 0.14). There were 10 518 (65%) with an obstetric-related ICU diagnosis, and 5545 (35%) with a non-obstetric ICU diagnosis. Mean (SD) age was 31 (6.4) years, 1463 (9.1%) were Indigenous, 2305 (14%) were transferred from another hospital, and 3008 (19%) received mechanical ventilation. Median [IQR] length of stay in hospital was 5.2 [3.1-7.9] days, which included 1.1 [0.7-1.8] days in ICU. There were 108 (0.7%) maternal deaths, most (n = 97, 90%) having a non-obstetric diagnosis. There was no change in risk-adjusted length of stay or mortality over time.

CONCLUSIONS

Obstetric patients account for a stable proportion of ICU admissions in Australia and New Zealand. These patients typically have a short length of ICU stay and low hospital mortality.

TWEETABLE ABSTRACT

Obstetric patients in Australia/New Zealand ICUs have a short length of ICU stay and low mortality.

Accuracy of contrast-enhanced CT and predictive factors for extracapsular spread in unknown primary head and neck squamous cell cancer

AIM

To determine the accuracy of contrast-enhanced computed tomography (CECT) for nodal extracapsular spread (ECS) and identify predictive radiological signs and clinicopathological features for ECS in unknown-primary head and neck squamous cell cancer (UPHNSCC).

MATERIALS AND METHODS

The CECT imaging of patients who underwent primary neck dissection for UPHNSCC during 2011-2015 was analysed. The largest pathological-looking node at each radiologically involved level was evaluated in consensus by two head and neck radiologists. Parameters included longest diameter, margin sharpness, haziness in adjacent fat, necrosis, and loss of fat plane with adjacent structures. Independent assessment was also made regarding the presence/absence of ECS. Findings and clinicopathological parameters were correlated with histopathology.

RESULTS

Thirty-one patients with 39 neck levels had metastatic nodal involvement determined on CECT. Confirmed ECS was found at 26 levels in 23 patients. Sensitivity of radiological assessment for ECS by nodal level was 81-85% (95% confidence interval [CI]=65-93%) and specificity 46-54% (95% CI=19-81%); kappa 0.87. On univariate analysis based on the largest involved node per patient, longest diameter being ≥30 mm (p=0.007), haziness in adjacent fat (p=0.023), increasing age (p=0.006), and more advanced pathological nodal status (p=0.027) were statistically significantly associated with ECS. Haziness and increasing age were independent predictors on multivariate analysis (odds ratio [OR]=26.4 and 1.24).

CONCLUSION

Expert assessment of ECS on CECT had good sensitivity with excellent interobserver agreement. A longest nodal diameter of ≥30 mm, haziness in the surrounding fat on CECT, advanced pathological nodal status, and advancing patient age were significantly associated with ECS in UPHNSCC patients, findings not previously reported.

Build better bones with exercise (B3E pilot trial): results of a feasibility study of a multicenter randomized controlled trial of 12 months of home exercise in older women with vertebral fracture

We pilot-tested a trial of home exercise on individuals with osteoporosis and spine fracture. Our target enrollment was met, though it took longer than expected. Participants stayed in the study and completed the exercise program with no safety concerns. Future trials should expand the inclusion criteria and consider other changes.

PURPOSE

Osteoporotic fragility fractures create a substantial human and economic burden. There have been calls for a large randomized controlled trial examining the effect of exercise on fracture incidence. The B3E pilot trial was designed to evaluate the feasibility of a large trial examining the effects of home exercise on individuals at high risk of fracture.

METHODS

Community-dwelling women ≥ 65 years with radiographically confirmed vertebral compression fractures were recruited at seven sites in Canada and Australia. We randomized participants in a 1:1 ratio to a 12-month home exercise program or equal attention control group, both delivered by a physiotherapist (PT). Participants received six PT home visits in addition to monthly phone calls from the PT and a blinded research assistant. The primary feasibility outcomes of the study were recruitment rate (20 per site in 1 year), retention rate (75% completion), and intervention adherence rate (60% of weeks meeting exercise goals). Secondary outcomes included falls, fractures and adverse events.

RESULTS

One hundred forty-one participants were recruited; an average of 20 per site, though most sites took longer than anticipated. Retention and adherence met the criteria for success: 92% of participants completed the study; average adherence was 66%. The intervention group did not differ significantly in the number of falls (IRR 0.97, 95% CI 0.58 to 1.63) or fragility fractures (OR 1.11, 95% CI 0.60 to 2.05) compared to the control group. There were 18 serious adverse events in the intervention group and 12 in the control group.

CONCLUSION

An RCT of home exercise in women with vertebral fractures is feasible but recruitment was a challenge. Suggestions are made for the conduct of future trials.

"Left to my own devices, I don't know": using theory and patient-reported barriers to move from physical activity recommendations to practice

Knowledge exchange with community-dwelling individuals across Ontario revealed barriers to implementation of physical activity recommendations that reflected capability, opportunity, and motivation; barriers unique to individuals with osteoporosis include fear of fracturing, trust in providers, and knowledge of exercise terminology. Using the Behaviour Change Wheel, we identified interventions (training, education, modeling) and policy categories (communication/marketing, guidelines, service provision).

INTRODUCTION

Physical activity recommendations exist for individuals with osteoporosis; however, to change behavior, we must address barriers and facilitators to their implementation. The purposes of this project are (1) to identify barriers to and facilitators of uptake of disease-specific physical activity recommendations (2) to use the findings to identify behavior change strategies using the Behaviour Change Wheel (BCW).

METHODS

Focus groups and semi-structured interviews were conducted with community-dwelling individuals attending osteoporosis-related programs or education sessions in Ontario. They were stratified by geographic area, urban/rural, and gender, and transcribed verbatim. Two researchers coded data and identified emerging themes. Using the Behaviour Change Wheel framework, themes were categorized into capability, opportunity, and motivation, and interventions were identified.

RESULTS

Two hundred forty community-dwelling individuals across Ontario participated (mean ± SD age = 72 ± 8.28). Barriers were as follows: capability: disease-related symptoms hinder exercise and physical activity participation, lack of exercise-related knowledge, low exercise self-efficacy; opportunity: access to exercise programs that meet needs and preferences, limited resources and time, physical activity norms and preferences; motivation: incentives to exercise, fear of fracturing, trust in exercise providers. Interventions selected were training, education, and modeling. Policy categories selected were communication/marketing, guidelines, and service provision.

CONCLUSIONS

Barriers unique to individuals with osteoporosis included the following: lack of knowledge on key exercise concepts, fear of fracturing, and trust in providers. Behavior change techniques may need tailoring to gender, age, or presence of comorbid conditions.

"I do not have time. Is there a handout I can use?": combining physicians' needs and behavior change theory to put physical activity evidence into practice

Guidelines for physical activity exist and following them would improve health. Physicians can advise patients on physical activity. We found barriers related to physicians' knowledge, a lack of tools and of physician incentives, and competing demands for limited time with a patient. We discuss interventions that could reduce these barriers.

INTRODUCTION

Uptake of physical activity (PA) guidelines would improve health and reduce mortality in older adults. However, physicians face barriers in guideline implementation, particularly when faced with needing to tailor recommendations in the presence of chronic disease. We performed a behavioral analysis of physician barriers to PA guideline implementation and to identify interventions. The Too Fit To Fracture physical activity recommendations were used as an example of disease-specific PA guidelines.

METHODS

Focus groups and semi-structured interviews were conducted with physicians and nurse practitioners in Ontario, stratified by type of physician, geographic area, and urban/rural, and transcribed verbatim. Two researchers coded data and identified emerging themes. Using the behavior change wheel framework, themes were categorized into capability, opportunity and motivation, and interventions were identified.

RESULTS

Fifty-nine family physicians, specialists, and nurse practitioners participated. Barriers were as follows: Capability-lack of exercise knowledge or where to refer; Opportunity-pragmatic tools, fit within existing workflow, available programs that meet patients' needs, physical activity literacy and cultural practices; Motivation-lack of incentives, not in their scope of practice or professional identity, competing priorities, outcome expectancies. Interventions selected: education, environmental restructuring, enablement, persuasion. Policy categories: communications/marketing, service provision, guidelines.

CONCLUSIONS

Key barriers to PA guideline implementation among physicians include knowledge on where to refer or what to say, access to pragmatic programs or resources, and things that influence motivation, such as competing priorities or lack of incentives. Future work will report on the development and evaluation of knowledge translation interventions informed by the barriers.

Mycobacterium tuberculosis resistance in pulmonary TB patients in Cameroon: a phenotypic susceptibility assay

OBJECTIVE

To determine the resistance of Mycobacterium tuberculosis to first- and second-line agents in adult pulmonary tuberculosis (TB) patients in Cameroon using a novel phenotypic assay.

SETTING

Samples were collected from TB patients at Bamenda Hospital in Bamenda, Cameroon.

DESIGN

Samples were collected consecutively from adult pulmonary TB patients over a 2-month period. TREK Sensititre(TM) MYCOTB panels were used to perform phenotypic drug susceptibility testing (DST). Susceptibility/resistance was determined by comparing minimum inhibitory concentrations to standard critical concentrations established for first- and second-line anti-tuberculosis drugs.

RESULTS

Of 103 sputum samples processed, growth on Löwenstein-Jensen media was confirmed in 78 samples, 65 of which were suitable for DST. Thirty-nine strains (60%) were susceptible to all first- and second-line drugs. Five strains (8%) were categorized as multidrug-resistant TB. Two strains (3%) were classified as pre-extensively drug-resistant TB. Of those isolates susceptible to first-line drugs, 20% were resistant to at least one second-line drug.

CONCLUSION

Antimicrobial resistance may be higher than assumed in TB strains in Cameroon, especially with regard to second-line drugs. There remains a need for rapid, comprehensive DST.

Current and potential renal applications of contrast-enhanced ultrasound

The combination of microbubble technology and complementary ultrasound techniques has resulted in the development of contrast-enhanced ultrasound (CEUS) and, although initial clinical applications largely focussed on the liver, these are now becoming more diverse. With regard to the kidney, it is a safe, well-tolerated, and reproducible technique, and in selected cases, can obviate the need for computed tomography or magnetic resonance imaging. A clear advantage is the absence of nephrotoxicity. With respect to the current and potential renal applications, it is a useful technique in the evaluation of pseudotumours, acute pyelonephritis, renal tumours, cystic lesions, vascular insults, and renal transplantation. It may also be of value for monitoring the kidney following anti-angiogenic treatment or nephron-sparing interventional techniques for renal tumours. Assessment of microvascular perfusion using time-intensity curves is also likely to have further far-reaching applications in the kidney as well as other organs.

Changing the referral criteria for bone scan in newly diagnosed prostate cancer patients

OBJECTIVES

The aim of this study was to correlate the prostate-specific antigen (PSA) level and Gleason score with staging bone scan result in patients with a new diagnosis of prostate cancer in order to establish the feasibility of implementing the European Association Urology guidelines, which state that a bone scan may not be indicated when PSA <20 in well-moderately differentiated tumours.

METHODS

We identified 633 patients retrospectively and 186 patients prospectively with a new diagnosis of prostate cancer undergoing a staging bone scan between March 2005 and January 2010. Patients were excluded if there was no Gleason score available or if the PSA level was checked over 3 months prior to bone scan. Bone scan results were analysed with respect to age, PSA level and Gleason score. In the case of an equivocal result, subsequent imaging was taken into consideration or the initial bone scan was re-reviewed. In persistently equivocal cases, all relevant imaging was assessed by a blinded panel of radiologists to allow a final decision to be made.

RESULTS

Of 672 patients aged 39-93 years (median 71 years), who fulfilled the inclusion criteria, 54 (8%) had evidence of bony metastases. PSA level and Gleason score were both independent predictors of bone scan positivity and their predictive value was additive p<0.01. None of the 357 patients with a PSA level of <20 and a Gleason score of <8 had a positive bone scan.

CONCLUSION

Staging bone scans in newly diagnosed prostate cancer patients with a PSA level of <20 and a Gleason score of <8 can be safely omitted, with these criteria having a negative predictive value of 100% in our series.

International albumin use: 1995 to 2006

Over the last ten years more reliable information regarding the risks and benefits of the use of albumin for fluid resuscitation has emerged. To determine what influence this has had on clinical practice, we sought to document albumin use (from mass of albumin supplied to hospitals) in 16 industrialised countries between 1995 and 2006. Data on national albumin and synthetic colloid use was sought from independent intensive care researchers and albumin issuers. The mass of albumin supplied per 10,000 persons on an annual basis by country and aggregated across the study countries was calculated. Volumes of synthetic colloid supplied per 10,000 persons were calculated. Data were obtained for 15 countries. Albumin use varied significantly between countries and throughout the observation period. Overall, aggregate albumin use decreased from a peak of 2.54 kg per 10,000 persons in 1995 to 1.40 kg per 10,000 persons in 1999; use has remained relatively constant since. Data on supply of synthetic colloids was available in only three countries and varied from 11.7 litres per 10,000 persons in Canada in 1995, to 231.8 litres per 10,000 persons in Denmark in 2004. Between 1995 and 1999 albumin use decreased and has been materially constant since; where data were available, use of synthetic colloids increased. Whether these practice changes have resulted in a net health gain or in harm requires further research.

Ovarian cancer stem-like side-population cells are tumourigenic and chemoresistant

Background:

Ovarian cancer is the most lethal gynaecological malignancy. Although ovarian cancer patients often respond initially to chemotherapy, they usually develop chemoresistance. We hypothesised that a small portion of ovarian cancer cells have stem-like cell properties that contribute to tumourigenesis and drug resistance.

Methods:

Flow cytometry and Hoechst 33342 efflux isolated side-population (SP) cells from ascites derived from ovarian cancer patients and from mice inoculated with human ovarian cancer cell lines. The SP cells were examined for stem cell markers OCT4, NANOG, STELLAR, and ABCG2/BCRP1 by immunocytochemistry and RT–PCR. The SP cells and non-SP cells were studied for tumourigenesis and chemoresistance in vitro and in vivo.

Results:

The SP cells expressed ABCG2/BCRP1, OCT4, STELLAR, and NANOG, detected by immunocytochemistry and RT–PCR. ABCG2/BCRP1 expression was higher in SP than in non-SP cells. Xenogeneic mice inoculated with SP cells yielded more tumours than did mice inoculated with non-SP cells. In parallel, SP cell culture resulted in extensive cell proliferation, which was markedly more than in non-SP cells. SP cells resisted chemotherapy compared with non-SP cells, both in vivo and in vitro.

Conclusion:

Ovarian cancer SP cells are tumourigenic and chemoresistant. ABCG2/BCRP1 has an important role in chemoresistance, which has implications for new therapeutic approaches.

Pandemic influenza A(H1N1)v in New Zealand: the experience from April to August 2009

Following the detection of imported cases of pandemic influenza A(H1N1)v on 25 April 2009, New Zealand implemented containment measures that appeared to slow establishment of the pandemic during May. The pandemic accelerated markedly in June, reaching a peak within four to six weeks, and has been declining since mid-July. By 23 August there had been 3,179 recorded cases (97.8% reported as confirmed), including 972 hospitalisations, 114 intensive care admissions, and 16 deaths. Influenza-like illness (ILI) surveillance in general practice suggests that 7.5% (95% CI: 3.4-11.2) of the population of New Zealand had symptomatic infection, giving a case fatality ratio of 0.005%. Hospitalisations were markedly higher for Māori (age standardised relative risk (RR)=3.0, 95% CI: 2.9-3.2) and Pacific peoples (RR=6.7, 95% CI: 6.2-7.1) compared with Europeans and others. The apparent decline of the pandemic (shown by all surveillance systems) cannot be fully explained. New Zealand remains in the middle of its traditional influenza season, the influenza A(H1N1)v virus appears relatively infectious, and we estimate that only about 11% of the population have been infected by this novel agent.

Experimental infection studies of UK Culicoides species midges with bluetongue virus serotypes 8 and 9

This paper describes a rapid, standardised method for testing the susceptibility to bluetongue virus (BTV) of northern Palaearctic Culicoides species midges that can be used to assess the competence of both field-caught and laboratory-infected midges. The method has been used to show that Culicoides scoticus can replicate btv serotype 8 and BTV serotype 9 strains to more than 3 log(10) TCID50/midge, the first evidence of the potential of this species to transmit BTV.

[HIV seroprevalence in ophthalmologic patients of Cameroon]

BACKGROUND

It is difficult to estimate the exact HIV infection rates in countries such as Cameroon because of diagnostic and statistical problems. The majority of people seek help from traditional healers outside the health system.

PATIENTS AND METHODS

A screening for human immunodeficiency virus type 1 (HIV-1) and type 2 (HIV-2) was performed on 2452 patients of the western province of Cameroon. All data were evaluated regarding HIV seroprevalence and ophthalmological findings in HIV-seropositive patients. The test covered all patients who came for cataract surgery (group 1), all outpatients with suspicious ophthalmological findings (group 2), and all remarkable patients of the collaborating department of general medicine (group 3) between 20 September 2000 and 20 September 2001.

RESULTS

Of the 2452 screened patients, 467 (19.0%) were HIV seropositive. A positive test result was obtained in 29 (5.5%) of the 525 patients in group 1, 154 (35.6%) of the 433 patients in group 2, and 284 (19.0%) of the 1494 patients in group 3. The main ocular manifestations of the 154 HIV-seropositive patients in group 2 were uveitis (17.6%), squamous cell carcinoma of the conjunctiva (14.9%), zoster ophthalmicus (14.9%), and corneal ulcers (11.0%).

CONCLUSIONS

This study shows that the seroprevalence of the screened population of Cameroon lies between 5.5% (results of group 1) and 19.0% (results of group 3).

Habitat selection by common brushtail possums in a patchy eucalypt-forestry environment

We investigated population density and patterns of habitat selection by the common brushtail possum (Trichosurus vulpecula fuliginosus) within a patchy forestry environment in north-west Tasmania. Population density was extremely low overall (0.04 animals.ha-1) and varied between habitats (0.01 ? 0.13 animals.ha-1). Selection indices from population surveys and animal movement data showed clear patterns for two closed habitats across two spatio-temporal scales: native forest was selected for, while 5 - 7 year old Eucalyptus nitens plantation was selected against, for both home range placement within the study area and habitats selectively used while foraging at night. Daytime habitat selection also showed the same pattern. We argue that native forest represented high quality habitat, offering both food and shelter (tree-hollows), while older plantation represented low quality habitat, lacking both of these resources. Results for open habitats (young Eucalyptus nitens plantation and grassland) were less clear. These patterns are discussed in relation to potential effects of a changing forestry landscape on this species.

Multidisciplinary HIV adherence intervention: a randomized study

Maintaining greater than 95% adherence to antiretroviral medication is necessary in order to have the greatest therapeutic impact on HIV infection. Furthermore, evidence suggests that adherence rates of between 70% and 89% are significantly associated with viral rebound and the development of drug resistance. Adherence rates at and above the 95% level are difficult for patients to achieve and maintain. Our aim was to determine if an adherence intervention could improve adherence among patients attending an ambulatory care clinic at a large public hospital. The intervention was delivered by a multidisciplinary team of health care professionals and consisted of education coupled with the provision of devices designed to assist patient memory and adherence. A crucial component of the intervention consisted of the identification of patient specific barriers to adherence and the development of strategies to circumvent these problems. Adherence was assessed using patient self-report over the past 4, 7, and 28 days and by calculation of the Morisky score. The study was conducted as a randomised controlled trial using the stepped wedge design with a total of 68 subjects randomised to receive the intervention over a 20-week period. Adherence before and after the intervention formed the analysis. There was a significant decrease in the number of missed doses over the past 4 (1.9 to 1.0, p < 0.001), 7 (3.0 to 1.8, p < 0.001) and 28 (7.4 to 4.2, p < 0.001) days and a decrease in the Morisky score, indicating an improvement in medication taking behaviour (1.3 to 0.5 p < 0.001).

Randomized trial of an adherence programme for clients with HIV

Our aim was to determine if a comprehensive adherence package improved self reported adherence to antiretroviral therapy. The adherence package included an education programme, individualized planning of regimens, and the opportunity for a patient to choose from a number of adherence aids and reminder devices. A randomized step wedge design was used. Forty-three individuals were randomized to begin the intervention over a five-month period. There was a substantial fall in the number of missed doses reported for the last four days (0.76 to 0.38, P =0.03) and last seven days (1.5 to 0.74, P =0.005) but not for the last 28 days (2.5 to 2.5, P =0.63). There was no statistical difference in the viral load or CD4 lymphocyte count in the period before or after the intervention. The Morisky score during the pre and post intervention periods was significantly different (P =0.006), 2.9 (SD 0.9) and 3.3 (SD 0.8) respectively. This adherence package improved self reported adherence during the last four and seven days.

Home ranges of sympatric red-necked wallabies, red-bellied pademelons and common brushtail possums in a temperate eucalypt forestry environment

We investigated home ranges of sympatric red-necked (or Bennett?s) wallabies Macropus rufogriseus rufogriseus, red-bellied pademelons Thylogale billardierii and common brushtail possums Trichosurus vulpecula fuliginosus within a forestry environment in north-west Tasmania. Six indiviuals of each species were radio-tracked between 7 and 11 months. Nocturnal and diurnal data were used to estimate Minimum Convex Polygon (MCP) home range, 95% fixed-Kernel (KE) home range and 50% KE core area. Home ranges (mean � s.e.) were as follows: M. r. rufogriseus MCP = 61 � 12 ha, KE = 41 � 3 ha; T. billardierii MCP = 22 � 5 ha, KE = 16 � 3 ha; and Tr. v. fuliginosus MCP = 39 � 8 ha, KE = 17 � 3 ha. M. r. rufogriseus had larger MCP home ranges than T. billardierii (P < 0.05), and larger KE home ranges and core areas than both T. billardierii and Tr. v. fuliginosus (P < 0.05), which reflected their larger body mass. Inter-sexual comparisons within the sexually dimorphic macropods showed that M. r. rufogriseus males had significantly larger MCP and KE home ranges and core areas than females (P < 0.05), and T. billardierii males tended to have a larger KE home ranges than females (P = 0.08). No inter-sexual difference in home range size was detected for Tr. v. fuliginosus.

Diet and diet selection of two species in the macropodid browser–grazer continuum— do they eat what they 'should'?

On the basis of their dentition, species of Macropus are predicted to be grazers and species of Thylogale are predicted to be browsers. We tested these predictions by comparing diet and diet selection of the red-necked wallaby (Macropus rufogriseus rufogriseus) and red-bellied pademelon (Thylogale billardierii), by analysing forestomach contents of animals that had fed in the same region of a young pine plantation. Grasses, followed by broad-leafed forbs, were the most abundant plant groups in the field (together comprising 71% of the plant biomass), and were also the main dietary components of both macropodid species (91%). No differences were detected in diet of the two species when summarised in terms of diet diversity, evenness or overlap. When diet selection was compared, however, distinct differences were found between the two species. Red-necked wallabies selected for grasses (74% of the diet compared with 55% in the field) whereas red-bellied pademelons selected for broad-leafed forbs (38% of the diet compared with 16% in the field). Feeding patterns were therefore consistent with dietary predictions, provided diet selection was considered rather than simply diet. Diet selection is more appropriate for testing dietary predictions, because it reflects animals' attempts to consume food items that they prefer, that is, that they are functionally suited to consuming, even when such items are not as abundant as less preferred food.

Endovascular repair of para-anastomotic aneurysms of the aorta and iliac arteries: preferred treatment for a complex problem

PURPOSE

Standard surgical repair of para-anastamotic aneurysms (PAAs) of the abdominal and thoracic aorta and the iliac arteries has been associated with high morbidity and mortality rates. We reviewed our continuing experience with endovascular repair of these lesions to determine whether this approach is favorable and durable.

METHODS

All patients with PAAs of the aorta or iliac arteries who underwent endovascular treatment of their lesions between August 1993 and July 1999 were prospectively followed up, and data on age, previous aortic pathology and surgery, size of PAA, time to diagnosis, and symptoms at presentation were recorded. Preoperative, intraoperative, and postoperative imaging studies were analyzed. All patients had endovascular stent-grafts placed under digital fluoroscopic guidance in the operating room. Data on intraoperative and postoperative complications, mortality, and endoleaks were reviewed.

RESULTS

From August 1993 to July 1999, 28 patients (20 men, 8 women) had 35 PAAs of the aorta or iliac arteries. There were 5 thoracic aortic, 12 abdominal aortic, and 18 iliac artery PAAs. Three patients had a contained rupture of their PAA. All patients who had originally undergone reconstruction for occlusive disease had lesions consistent with false aneurysms, whereas 73% of the aortic or iliac PAAs in patients originally treated for aneurysm disease appeared to be true aneurysms. Thirty-four of 35 PAAs were successfully excluded with stent-grafts (97%). There was one death at 30 days (3.6%) in a patient who was successfully treated endovascularly for a contained rupture of a thoracic PAA. There were four major postoperative complications (14.2%) in the 28 patients who were treated. One patient had continued perfusion of a thoracic aortic PAA (type I endoleak). The in-hospital length of stay after endovascular repair of PAA was 4 days (range, 1-18 days). The mean follow-up period was 21 months (range, 1-68 months).

CONCLUSION

Endovascular repair of aortic and iliac artery PAAs is technically feasible and provides a high rate of lesion exclusion. Morbidity and mortality rates appear lower than those reported for open surgical repair. These patients can typically be discharged by the second postoperative day. Endovascular therapy for stable ruptured PAAs can be successfully performed and should be considered as an option only when appropriate devices and expertise are available. For uncomplicated PAAs of the aorta and iliac arteries, endovascular therapy may be more favorable than surgical repair.

Il-13 and IFN-gamma: interactions in lung inflammation

Chronic inflammatory diseases of the lungs, such as asthma, are frequently associated with mixed (Th2 and Th1) T cell responses. We examined the impact of critical Th1 and Th2 cytokines, IFN-gamma and IL-13, on the responses in the lungs. In a mouse model of airway inflammation induced by mixed T cell responses, the number of Th1 (IFN-gamma-positive) cells was found to be negatively correlated with airway hyperreactivity. In these mice, blockade of IL-13 partially inhibited airway hyperreactivity and goblet cell hyperplasia but not inflammation. In contrast, in mice that responded with a polarized Th2 response to the same Ag, blockade of IL-13 inhibited airway hyperreactivity, goblet cell hyperplasia, and airway inflammation. These results indicated that the presence of IFN-gamma would modulate the effects of IL-13 in the lungs. To test this hypothesis, wild-type mice were given recombinant cytokines intranasally. IFN-gamma inhibited IL-13-induced goblet cell hyperplasia and airway eosinophilia. At the same time, IFN-gamma and IL-13 potentiated each other's effects. In the airways of mice given IL-13 and IFN-gamma, levels of IL-6 were increased as well as numbers of NK cells and of CD11c-positive cells expressing MHC class II and high levels of CD86. In conclusion, IFN-gamma has double-sided effects (inhibiting some, potentiating others) on IL-13-induced changes in the lungs. This may be the reason for the ambiguous role of Th1 responses on Th2 response-induced lung injury.

Histopathologic analysis of endovascular stent grafts from patients with aortic aneurysms: Does healing occur?

BACKGROUND

Research with animal models has demonstrated tissue healing of endovascular grafts in both native arterial segments and in experimentally created arterial aneurysms. Fundamental to the successful clinical use of endovascular grafts for the treatment of aneurysmal disease is the creation of a permanent hemostatic seal between the graft ends and the arterial wall. Characteristics of this healing process in patients with aneurysmal disease have not been fully studied. In this study, we analyzed the macroscopic and histopathologic changes of the arterial wall after endovascular repair of aortic aneurysms.

METHODS

Over a 7-year period, 313 patients were treated with endovascular grafts to exclude arterial aneurysms of the thoracic and abdominal aorta. Of these patients, 11 had their endovascular grafts recovered for analysis. Five graft specimens were recovered during subsequent open aortic surgery. Six grafts were recovered at autopsy after the death of the patient of causes unrelated to the patient's endovascular graft. All specimens were fixed in formalin. Histologic analysis included light microscopy with hematoxylin and eosin and trichrome stains. Well-preserved specimens were selected after light microscopic examination and postfixed in 3% buffered glutaraldehyde for electron microscopy. The aortas from autopsy specimens were removed en bloc and fixed in formalin; representative regions of each graft were sectioned for analysis. Adherence of the graft to the vessel wall was categorized as densely adherent or easily separated after graft explantation. Traction applied to the graft-aortic anastomosis was equal to traction generated by suspending a standardized 2-kg weight. Infrarenal graft specimens were obtained with supraceliac aortic clamping, longitudinal aortotomy, and graft sampling before endograft revision.

RESULTS

In eight patients, endograft fixation was found to be firmly adherent to the arterial wall. A translucent film of fibrinous material was consistently seen across the entire luminal surface of the endograft. Light and electron microscopy failed to demonstrate an endothelial layer or organized pseudointima at the graft-artery interface.

CONCLUSION

Despite suggestive experimental data regarding endograft healing in animals, minimal graft incorporation was apparent in the stent grafts recovered in this study. A greater emphasis on the construction and mechanism of fixation of endograft attachment systems will be important for long-term device function.

Evaluation of line-transect sampling to estimate nocturnal densities of macropods in open and closed habitats

Walked line transects were evaluated for estimating nocturnal densities of red-necked wallaby (Macropus rufogriseus) and the red-bellied pademelon (Thylogale billardierii) in a range of open and closed habitats. The use of cleared transect lines in densely vegetated habitats reduced noise produced by travelling, while permanent grid markers facilitated collection of perpendicular distance data at night. Results from sighting histograms indicated that animals did not display evasive movement in response to the observer before detection. The probabilities of detecting the macropod species varied significantly between habitats. Significant differences in probabilities of detection were also recorded within species between habitats. Consequently, line-transect sampling is recommended over strip-transect sampling for estimating species abundance when more than one species and/or habitat are of interest. Recommendations are made, however, for forest managers wanting to monitor macropod populations on newly established plantations, when line-transect sampling is not feasible and strip-transect sampling is the only alternative.

Observer error in counts of macropod scats

The accuracy of faecal pellet, or scat, count data can be reduced by observer error. Two experiments were carried out to determine what proportion of Bennett’s wallaby (Macropus rufogriseus) and Tasmanian pademelon (Thylogale billardierii) scats were misidentified by observers and what proportion of scats were overlooked during counts. Observers did not always correctly identify the species from which scats originated. For each species, this affected estimates of the proportion of scats that were present. Observers still made errors even when they did not attempt to make identifications for any scats that they felt were not distinct in form. On average, there was no significant difference in the proportion of scats that were misidentified by inexperienced and experienced observers. Between 3% and 12% of scats were overlooked during standard counts. The probability of overlooking a scat was positively related to vegetation height and negatively related to vegetation cover.

Cost comparison of antibacterial therapies for serious infections. A New Zealand 3-hospital study

OBJECTIVE

The first aim was to identify and determine the economic costs of the regimens currently used in 3 New Zealand hospitals in the treatment of bacterial infections in haematology patients with febrile neutropenia and in intensive care patients with severe infections. The second was to develop a spreadsheet-based decision analytic model for use by hospital decision-makers as an aid in evaluating the comparative cost of drug regimens.

DESIGN AND SETTING

The research utilised time and motion and microcosting techniques. The analytical perspective adopted for the study was that of a hospital administrator or clinical manager.

PATIENTS AND INTERVENTIONS

Patients were eligible for inclusion in the study if either they were treated with the imipenem/cilastatin monotherapy, or could have been treated with this regimen. The final analysis considered 360 patient-treatment days and 8 antibacterials.

MAIN OUTCOME MEASURES AND RESULTS

Drug acquisition cost ranged from 4.52 New Zealand dollars ($NZ; 1997 values) per patient-treatment day for gentamicin to $NZ104.81 for imipenem. The cost per patient-treatment day (when other cost components such as fluid additives, giving sets and needles were added) ranged from $NZ8.75 for gentamicin to $NZ129.12 for tazobactam. Drug acquisition cost, as a percentage of total drug preparation and administration cost, ranged from 52% for gentamicin to 93% for piperacillin. Giving sets and intravenous (i.v.) fluids were found to be important cost items when they were required specifically for the treatment regimen. There was a mean monitoring rate of 0.40 at a cost of $NZ6.41 per patient-treatment day for gentamicin. It was estimated that nephrotoxicity could add between $NZ23 and $NZ43 per day to the cost of aminoglycoside treatment.

CONCLUSIONS

Although the small sample sizes of the study mean that results should be regarded as indicative rather than conclusive, there were sufficient information to construct a working model and show how the total cost of an antibacterial regimen could be evaluated in practical terms. The important cost drivers were found to be drug cost, the use of fluids and giving sets, and monitoring.

Book review: Marsupial Nutrition by Ian D. Hume

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Indirect calorimetry

Indirect calorimetry can be a useful tool to define nutritional status, determine nutritional requirements, and assess response to nutritional interventions. Measurements of oxygen consumption and carbon dioxide production may be used to determine cardiac output and work of breathing, and estimate the components of minute ventilation. An understanding of the potential technical and physiological pitfalls is necessary to obtain meaningful and useful information.

The medial tibial syndrome. The role of surgery

Among authors over the past 35 years, medial tibial syndrome, or "shin splints," has been interpreted to mean many different things. We present a review of the literature to attempt to ascribe one definition to this clinical entity, and to clearly define its symptoms, signs, pathophysiology, biomechanics, and treatment. In addition, we describe our results with five patients whose seven affected limbs eventually required surgery for this condition, and we compare them to the results in the literature.

Stimulation of vascular Na(+)-K(+)-ATPase activity by nitric oxide: a cGMP-independent effect

An endothelium-derived factor with the properties of nitric oxide (NO) has been implicated in the regulation of Na(+)-K(+)-adenosinetriphosphatase (ATPase) activity in vascular smooth muscle. To examine this phenomenon further and to explore its modulation by guanosine 3',5'-cyclic monophosphate (cGMP), studies were carried out in the isolated rabbit aorta. Incubation of endothelium-denuded rings with NO (1 microM) or sodium nitroprusside (SNP, 10 microM) caused a time-dependent increase in ouabain-sensitive (OS) 86Rb uptake with the maximal stimulation (approximately 170%) seen after 20 min. In contrast, increases in cGMP concentration caused by NO and SNP (40- and 20-fold increases, respectively) were transient, with peak values observed after 2 min and significantly lower values by 10 min. The ability of NO or SNP to increase OS Rb uptake in endothelium-denuded rings was not mimicked by incubation with 8-bromo- or dibutyryl-cGMP or increases in cGMP caused by treatment with the phosphodiesterase inhibitor isobutylmethylxanthine. Depletion of intracellular cGMP levels by the guanylate cyclase inhibitor LY83583 also did not alter OS Rb uptake. SNP-stimulated OS Rb uptake was not inhibited by LY83583 in endothelium-denuded rings; however, it was completely prevented by the Na(+)-H+ exchange inhibitors amiloride and ethylisopropylamiloride. The results suggest that NO stimulates Na(+)-K(+)-ATPase activity in rabbit aorta by a mechanism independent of its ability to increase the intracellular cGMP concentration. They also suggest that NO may stimulate Na(+)-K(+)-ATPase activity secondary to increases in Na(+)-H+ exchange.

Role of endothelium-derived nitric oxide in stimulation of Na(+)-K(+)-ATPase activity by endothelin in rabbit aorta

An endothelium-derived factor with the properties of nitric oxide (NO) has recently been implicated in the regulation of basal Na(+)-K(+)-adenosinetriphosphatase (ATPase) activity in vascular smooth muscle. To determine whether this factor also plays a role in the stimulation of ouabain-sensitive (OS) 86Rb uptake by specific agonists, studies were carried out using rabbit aortic rings. In endothelium-intact rings incubated for 3 h with Krebs-Henseleit solution containing 5.5 mM glucose, endothelin (ET) caused a concentration-dependent increase in OS 86Rb uptake (maximal increase = 205%, with 100 nM ET). Incubation with phenylephrine (Phe; 0.1 and 1 microM) or phorbol 12,13-dibutyrate (PDBu; 0.1 microM), under the same conditions, increased OS 86Rb uptake by 128, 144, and 140%, respectively. Removal of endothelium before incubation decreased the ability of ET to stimulate OS 86Rb uptake by 38-45%, but it did not diminish the stimulation of OS 86Rb uptake by Phe or PDBu. An increase in the concentration of glucose from 5.5 to 44 mM diminished ET-stimulated OS 86Rb uptake by 50% in endothelium-intact rings but had no effect on Phe- or PDBu-induced increases in OS 86Rb uptake. Addition of the NO synthase inhibitor NG-monomethyl-L-arginine (L-NMMA; 0.3 mM) to the medium decreased ET-stimulated OS 86Rb uptake by 40%. Guanosine 3',5'-cyclic monophophate (cGMP) formation in endothelium-intact rings was also increased (65%) by ET but not by Phe or PDBu. The increase in cGMP by ET was totally inhibited by L-NMMA or endothelium denudation.(ABSTRACT TRUNCATED AT 250 WORDS)

Diet selection by a ruminant generalist browser in relation to plant chemistry

Captive mule deer (Odocoileus hemionus hemionus) and black-tailed deer (O. h. sitkensis) were used in cafeteria-type, two choice feeding trials to test the hypothesis that digestible dry matter (energy) and nontannin phenolics of tree, shrub, and forb leaves are major determinants of diet preference. Deer selected plants in relation to a trade-off between the benefit derived from digestible dry matter and the cost of nontannin phenolics presumably associated with toxicity when absorbed. When one of the forages contained both the highest digestible dry matter and lowest nontannin phenolics, the deer always preferred that plant. When one forage had the highest digestible dry matter but the other plant had the lowest nontannin phenolics, the deer selected the high-energy plant when the difference in nontannin phenolics was relatively small, but they preferred the low-energy plant when the other forage had much higher levels of nontannin phenolics. Tannins influenced diet choice only as one of the factors reducing digestible dry matter in these forages. Apparently total dry-matter intake was constrained by the nontannin phenolic fraction but not by tannins. Tannins and nontannin phenolics both contribute to defending plants against browsers.

Validation of a clinical antisaccadic eye movement test in the assessment of dementia

The ability to generate antisaccades (eye movements deliberately made in the direction opposite to that of a visual stimulus) may be used to assess central nervous system function in a variety of neurologic and psychiatric disorders. However, the usefulness of this paradigm in clinical practice is limited by the need for an oculographic laboratory. We describe a clinical version of such an antisaccadic task and present normative data from 332 subjects. We also examined clinical antisaccades and cognitive performance in 30 patients with Alzheimer's disease, five patients with Huntington's disease, and 12 patients with pseudodementia. In Alzheimer's disease, error rates in the clinical antisaccadic test correlated well with those from a laboratory-based antisaccadic task measured on the same day by infrared oculography, confirming that the clinical antisaccadic test is a valid analog of the more sophisticated laboratory paradigms. Clinical antisaccadic error rates correlated strongly with the severity of dementia in Alzheimer's disease, and correlations with cognitive performance suggested that the clinical antisaccadic test may have some specificity for frontal lobe dysfunction. Patients with pseudodementia had normal clinical antisaccadic error rates, and the test may therefore be of use in differentiating dementia from pseudodementia. This clinical antisaccadic test provides a simple, reliable, and inexpensive quantitative clinical tool that is of value in the assessment of disturbances of higher cortical function.

Awake inspiratory airway occlusion in normal humans is followed by hyperpnea and hypocapnia

The ventilatory response following 15 seconds of inspiratory airway occlusion at functional residual capacity (FRC) was studied in nine normal supine awake subjects. Expired minute ventilation (VE), CO2 output (VCO2), tidal volume (VT), and end-tidal PCO2 (PETCO2) were measured on a breath-by-breath basis. Alveolar PCO2 rose 5.6 mm Hg during the apnea (P less than 0.001). Ventilation rose 10.8 L/min on the first breath following apnea and remained elevated above control measurements for five breaths (P less than 0.05). The persistent hyperpnea was due to an increase in tidal volume and was associated with alveolar hypocapnia for 6 breaths or 30 sec (P less than 0.05) and an increase in CO2 output for 4 breaths (P less than 0.05). Changes in end-tidal PCO2 correlated with excess CO2 output relative to control measurements immediately prior to airway occlusion (P less than 0.03). After 15 sec airway occlusion at FRC, there is alveolar hypercapnia with a 2.6-fold first breath rise in ventilation. Persistent alveolar hyperventilation lasting 30 sec following airway occlusion may be due to delays in central chemoreceptor response or an afterdischarge phenomenon. This overshoot hypercapnia following airway occlusion may have some relevance to the development of central apneas following obstructive apnea episodes.