Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Awareness and agreement with neurofibromatosis care guidelines among U.S. neurofibromatosis specialists

Introduction

The neurofibromatoses (NF) are a group of rare, genetic diseases sharing a predisposition to develop multiple benign nervous system tumors. Given the wide range of NF symptoms and medical specialties involved in NF care, we sought to evaluate the level of awareness of, and agreement with, published NF clinical guidelines among NF specialists in the United States.

Methods

An anonymous, cross-sectional, online survey was distributed to U.S.-based NF clinicians. Respondents self-reported demographics, practice characteristics, awareness of seven NF guideline publications, and level of agreement with up to 40 individual recommendations using a 5-point Likert scale. We calculated the proportion of recommendations that each clinician rated “strongly agree”, and assessed for differences in guideline awareness and agreement by respondent characteristics.

Results

Sixty-three clinicians (49% female; 80% academic practice) across > 8 medical specialties completed the survey. Awareness of each guideline publication ranged from 53%-79% of respondents; specialists had higher awareness of publications endorsed by their medical professional organization (p < 0.05). The proportion of respondents who “strongly agree” with individual recommendations ranged from 17%-83%; for 16 guidelines, less than 50% of respondents “strongly agree”. There were no significant differences in overall agreement with recommendations based on clinicians’ gender, race, specialty, years in practice, practice type (academic/private practice/other), practice location (urban/suburban/rural), or involvement in NF research (p > 0.05 for all).

Conclusions

We identified wide variability in both awareness of, and agreement with, published NF care guidelines among NF experts. Future quality improvement efforts should focus on evidence-based, consensus-driven methods to update and disseminate guidelines across this multi-specialty group of providers. Patients and caregivers should also be consulted to proactively anticipate barriers to accessing and implementing guideline-driven care. These recommendations for improving guideline knowledge and adoption may also be useful for other rare diseases requiring multi-specialty care coordination.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-022-02196-x.

The impact of the COVID-19 pandemic on neurofibromatosis clinical care and research

Purpose

The coronavirus disease 2019 (COVID-19) pandemic has had unprecedented impact on the provision of medical care for genetic disorders. The purpose of this study was to assess the effects of the pandemic on neurofibromatosis (NF) care and research.

Methods

Sixty-three United States NF clinics were surveyed to identify the impact of the pandemic on clinician role, patient volume, continuity of guideline-driven surveillance, research protocols, and use of (and satisfaction with) telehealth for the delivery of NF care.

Results

Fifty-two clinic directors or their representatives completed the survey (83% response rate). About 2/3 of the clinics reported a greater than 50% decrease in the number of available patient appointments, and modified clinical surveillance and research protocols. Fifty-one clinics (98%) newly instituted telehealth during the pandemic. Barriers to telehealth prior to the pandemic were insurance reimbursement concerns and lack of infrastructure. Since telehealth was initiated, high provider satisfaction was reported with ease of use. The most common area of concern was related to inability to perform a physical examination.

Conclusion

Results show marked impacts on NF care and research since the beginning of the pandemic, with potential long-term changes related to the introduction (or adoption) of telehealth for clinical care.

Phenotypic heterogeneity of neurofibromatosis type 1 in a large international registry

Neurofibromatosis type 1 (NF1) is a rare genetic disorder, characterized by the development of benign and malignant nerve tumors. Although all individuals with NF1 harbor genetic alterations in the same gene, the clinical manifestations of NF1 are extremely heterogeneous even among individuals who carry identical genetic defects. In order to deepen the understanding of phenotypic manifestations in NF1, we comprehensively characterized the prevalence of 18 phenotypic traits in 2051 adults with NF1 from the Children's Tumor Foundation's NF1 registry. We further investigated the coassociation of traits and found positive correlations between spinal neurofibromas and pain, spinal neurofibromas and scoliosis, spinal neurofibromas and optic gliomas, and optic gliomas and sphenoid wing dysplasia. Furthermore, with increasing numbers of cutaneous neurofibromas, the odds ratio of malignant peripheral nerve sheath tumor increased. Phenotypic clustering revealed 6 phenotypic patient cluster subtypes: mild, freckling predominant, neurofibroma predominant, skeletal predominant, late-onset neural severe, and early-onset neural severe, highlighting potential phenotypic subtypes within NF1. Together, our results support potential shared molecular pathogenesis for certain clinical manifestations and illustrate the utility of disease registries for understanding rare diseases.

The Use of MEK Inhibitors in Neurofibromatosis Type 1-Associated Tumors and Management of Toxicities

Early-phase clinical trials using oral inhibitors of MEK, the mitogen-activated protein kinase kinase, have demonstrated benefit for patients with neurofibromatosis type 1 (NF1)-associated tumors, particularly progressive low-grade gliomas and plexiform neurofibromas. Given this potential of MEK inhibition as an effective medical therapy, the use of targeted agents in the NF1 population is likely to increase substantially. For clinicians with limited experience prescribing MEK inhibitors, concern about managing these treatments may be a barrier to use. In this manuscript, the Clinical Care Advisory Board of the Children's Tumor Foundation reviews the published experience with MEK inhibitors in NF1 and outlines recommendations for side-effect management, as well as monitoring guidelines. These recommendations can serve as a beginning framework for NF providers seeking to provide the most effective treatments for their patients. IMPLICATIONS FOR PRACTICE: Neurofibromatosis type 1 (NF1) clinical care is on the cusp of a transformative shift. With the success of recent clinical trials using MEK inhibitors, an increasing number of NF1 patients are being treated with MEK inhibitors for both plexiform neurofibromas and low-grade gliomas. The use of MEK inhibitors is likely to increase substantially in NF1. Given these changes, the Clinical Care Advisory Board of the Children's Tumor Foundation has identified a need within the NF1 clinical community for guidance for the safe and effective use of MEK inhibitors for NF1-related tumors. This article provides a review of the published experience of MEK inhibitors in NF1 and provides recommendations for monitoring and management of side effects.

Activated carbon biochar from municipal waste as a sorptive agent for the removal of polyaromatic hydrocarbons (PAHs), phenols and petroleum based compounds in contaminated liquids

Wastewater (WW) sludge cake is problematic to dispose of with treatment unable to remove organic pollutants. Typical disposal options include landfill or deposition on agricultural land, at considerable expense and environmental impact. Pyrolysis can recycle this waste to biochar however, additional unwanted organic pollutants are generated, differing in composition and volume according to the feedstock. These pollutants can be captured in solvent impingers or 'scrubbers' to avoid environmental release but lead to alternative waste. Both activated carbon and biochar are proven clean-up methods for organic pollutants with pine wood biochar showing changes in extraction selectivity with preparation temperature. Activated carbon biochar (ACB) from pine wood has also been successfully compared as a substitute at reduced cost and improved efficacy. To our knowledge, ACB from sludge cake has remained untested along with its application to clean-up solvent scrubbers. We have investigated this material from two WW treatment plants (UK and Ghana) as a sorbent, generated at 400 and 700 °C, to minimise contamination of liquids from pyrolysis and, petrochemicals in the event of a spill. This study confirmed the use and selective production of ACB for preferential clean-up of specific pollutants. Despite high temperature pine wood ACB proving most effective in removing petrochemical mixtures (>76%) extractions of equivalent repeatability and reasonable recovery were achieved with low temperature sludge cake ACB. This re-use of waste sludge cake offers improved thermochemical (recycling) and WW process efficiency, limiting the environmental impact and overall operational costs, minimising waste for disposal.

Increasing access to specialty care for rare diseases: a case study using a foundation sponsored clinic network for patients with neurofibromatosis 1, neurofibromatosis 2, and schwannomatosis

Background

Our primary aim was to assess the ability of a non-profit foundation-sponsored clinic network to facilitate access to specialized care for patients with neurofibromatoses (NF), a group of neurogenetic disorders including NF1, NF2, and schwannomatosis (SWN). Our secondary aim was to identify how our findings in NF could be applied more broadly to other rare diseases.

Methods

We retrospectively reviewed aggregate data on patient volume reported by specialty NF clinics in a nonprofit network from 2008 to 2015. We classified clinics as high or low volume for disease type (NF1 and NF2/schwannomatosis) and pediatric/adult care. We compared clinic-level data to self-reported patient-level data from a large online patient registry.

Results

Between 2008 and 2015, the number of certified NF clinics grew from 32 to 50, and annual patient volume rose from 6776 to 10,245 patients (13% of the total estimated U.S. NF patient population). For patient registry participants (n = 4476), the median driving distance to the nearest network clinic was 51.3 miles. Driving distances to reach high-volume centers were elevated for adults compared to children (295.8 vs. 67.9 miles), and schwannomatosis and NF2 patients compared to NF1 patients (310.9 vs. 368.1 vs. 161.7 miles). Of registry participants reporting their location of care (n = 2271), only 43.2% received care in a network specialty clinic, with especially low rates of attendance in the Southwest and Far West.

Conclusions

While the number of certified NF clinics and volume of patients seen in these clinics has increased, many NF patients still do not attend specialty clinics and/or travel a significant distance for care. Geographic access to care is more limited for adults, patients with rarer conditions, and patients in the Western U.S. Potential measures to improve access to specialty care for people living with NF and other rare diseases are discussed.

Paediatric intensive care and neonatal intensive care airway management in the United Kingdom: the PIC-NIC survey

In 2011, the Fourth National Audit Project (NAP4) reported high rates of airway complications in adult intensive care units (ICUs), including death or brain injury, and recommended preparation for airway difficulty, immediately available difficult airway equipment and routine use of waveform capnography monitoring. More than 80% of UK adult intensive care units have subsequently changed practice. Undetected oesophageal intubation has recently been listed as a 'Never Event' in UK practice, with capnography mandated. We investigated whether the NAP4 recommendations have been embedded into paediatric and neonatal intensive care practice by conducting a telephone survey of senior medical or nursing staff in UK paediatric intensive care units (PICUs) and neonatal intensive care units (NICUs). Response rates were 100% for paediatric intensive care units and 90% for neonatal intensive care units. A difficult airway policy existed in 67% of paediatric intensive care units and in 40% of neonatal intensive care units; a pre-intubation checklist was used in 70% of paediatric intensive care units and in 42% of neonatal intensive care units; a difficult intubation trolley was present in 96% of paediatric intensive care units and in 50% of neonatal intensive care units; a videolaryngoscope was available in 55% of paediatric intensive care units and in 29% of neonatal intensive care units; capnography was 'available' in 100% of paediatric intensive care units and in 46% of neonatal intensive care units, and 'always available' in 100% of paediatric intensive care units and in 18% of neonatal intensive care units. Death or serious harm occurring secondary to complications of airway management in the last 5 years was reported in 19% of paediatric intensive care units and in 26% of neonatal intensive care units. We conclude that major gaps in optimal airway management provision exist in UK paediatric intensive care units and especially in UK neonatal intensive care units. Wider implementation of waveform capnography is necessary to ensure compliance with the new 'Never Event' and has the potential to improve airway management.

Cutaneous neurofibromas in the genomics era: current understanding and open questions

Cutaneous neurofibromas (cNF) are a nearly ubiquitous symptom of neurofibromatosis type 1 (NF1), a disorder with a broad phenotypic spectrum caused by germline mutation of the neurofibromatosis type 1 tumour suppressor gene (NF1). Symptoms of NF1 can include learning disabilities, bone abnormalities and predisposition to tumours such as cNFs, plexiform neurofibromas, malignant peripheral nerve sheath tumours and optic nerve tumours. There are no therapies currently approved for cNFs aside from elective surgery, and the molecular aetiology of cNF remains relatively uncharacterised. Furthermore, whereas the biallelic inactivation of NF1 in neoplastic Schwann cells is critical for cNF formation, it is still unclear which additional genetic, transcriptional, epigenetic, microenvironmental or endocrine changes are important. Significant inroads have been made into cNF understanding, including NF1 genotype–phenotype correlations in NF1 microdeletion patients, the identification of recurring somatic mutations, studies of cNF-invading mast cells and macrophages, and clinical trials of putative therapeutic targets such as mTOR, MEK and c-KIT. Despite these advances, several gaps remain in our knowledge of the associated pathogenesis, which is further hampered by a lack of translationally relevant animal models. Some of these questions may be addressed in part by the adoption of genomic analysis techniques. Understanding the aetiology of cNF at the genomic level may assist in the development of new therapies for cNF, and may also contribute to a greater understanding of NF1/RAS signalling in cancers beyond those associated with NF1. Here, we summarise the present understanding of cNF biology, including the pathogenesis, mutational landscape, contribution of the tumour microenvironment and endocrine signalling, and the historical and current state of clinical trials for cNF. We also highlight open access data resources and potential avenues for future research that leverage recently developed genomics-based methods in cancer research.

Current status and recommendations for biomarkers and biobanking in neurofibromatosis

OBJECTIVE

Clinically validated biomarkers for neurofibromatosis 1 (NF1), neurofibromatosis 2 (NF2), and schwannomatosis (SWN) have not been identified to date. The biomarker working group's goals are to (1) define biomarker needs in NF1, NF2, and SWN; (2) summarize existing data on biomarkers in NF1, NF2, and SWN; (3) outline recommendations for sample collection and biomarker development; and (4) standardize sample collection and methodology protocols where possible to promote comparison between studies by publishing standard operating procedures (SOPs).

METHODS

The biomarker group reviewed published data on biomarkers in NF1, NF2, and SWN and on biobanking efforts outside these diseases via literature search, defined the need for biomarkers in NF, and developed recommendations in a series of consensus meetings.

RESULTS

We describe existing biomarkers in NF and report consensus recommendations for SOP and a minimal clinical dataset to accompany samples derived from patients with NF1, NF2, and SWN in decentralized biobanks.

CONCLUSIONS

These recommendations are intended to provide clinicians and researchers with a common set of guidelines to collect and store biospecimens and for establishment of biobanks for NF1, NF2, and SWN.

Risk factors in equine transport-related health problems: A survey of the Australian equine industry

BACKGROUND

Transportation can affect equine health and is a potential source of economic loss to the industry.

OBJECTIVES

To identify journey (duration, vehicle, commercial or noncommercial) and horse (sex, age, breed, use, amateur or professional status) characteristics associated with the development of transport-related health problems in horses.

STUDY DESIGN

Cross-sectional online survey.

METHODS

An online survey was conducted targeting amateur and professional participants in the Australian equine industry; eligible respondents were required to organise horse movements at least monthly. Respondents provided details of the last case of a transport-related health problem that had affected their horse(s). Associations between type of health problem, journey and horse characteristics were examined with multivariable multinomial regression analysis.

RESULTS

Based on 214 responses, health problems were classified as injuries, muscular problems, heat stroke, gastrointestinal and respiratory problems, and death or euthanasia. Respiratory problems were reported most frequently (33.7%), followed by gastrointestinal problems (23.8%) and traumatic injuries (16.3%). The type of health problem was associated with journey duration (P<0.001) and horse breed (P = 0.001). Injuries were more likely to occur on short journeys, whereas more severe illnesses (gastrointestinal and respiratory problems, and death or euthanasia) were more likely to occur on long journeys. Using Standardbreds as the reference group, Thoroughbreds, Arabians and Warmbloods were more likely to experience a severe illness than an injury.

MAIN LIMITATIONS

Self-selected participation in the study and the self-reported nature of transport-related problems.

CONCLUSIONS

Horses undertaking journeys of longer than 24 h are at greater risk for the development of severe disease or death. Further studies on long-haul transportation effects are required to safeguard the welfare of horses moved over long distances.

Abstract 772: The molecular landscape of dermal neurofibromatosis

Background: Neurofibromatosis type I (NF1) is a genetic disorder that disrupts neurological tissue growth and can lead to a diverse set of symptoms including systematic growth of benign tumors, learning disorders and bone deformities. It is a rare disease occurring in only 1 in 3,000 people worldwide. While the disease has been linked to loss of function in the NF1 gene - a known tumor suppressor - there is a high degree of phenotypic diversity in the NF1 patient population, making it difficult to identify the underlying cause of the disease and treat it effectively. In this work we seek to improve overall knowledge of dermal NF1 through global molecular characterization of the disease.

Methods: We have collected four dermal neurofibromas and peripheral blood from each of 11 NF1 patients. We analyzed each sample using (1) Whole genome sequencing (WGS) on the Illumina HiSeq X platform, (2) Illumina OMNI2.5 Arrays (3) RNA-Sequencing on an Illumina HiSeq v4 machine and (4) iTRAQ-labeled proteomics. WGS data for both tumor and blood samples from each patient were used to identify patient-specific germ-line mutations as well as tumor-specific somatic mutations in each sample. Single nucleotide polymorphisms identified by the OMNI Arrays were used to identify copy number alterations in both blood and tumor samples. RNA-Seq data and proteomics data were mapped to transcripts and proteins respectively.

Results: Preliminary analysis of this data illustrates a diverse genomic landscape of NF1. Hierarchical clustering of copy number alterations largely show samples clustering by tissue, suggesting that most copy number alterations are somatic and not shared across the germline. However, there are two patients that show germline copy number alterations, including one patient with loss in the NF1 region. WGS analysis suggests similar diversity with each patient possessing a distinct combination of germline and somatic mutations of NF1 and other cancer-related genes. Cluster analysis of the RNA-Seq data shows no patient-specific clusters, suggesting that that each tumor executes a unique transcriptional program.

Conclusion: This work represents a first-ever attempt to profile the diversity of dermal neurofibromatosis at a molecular level. Preliminary analysis of the data underscores the complexity of this disease and explains, in part, previous difficulty in identifying effective treatments. Ongoing work includes expanding the analysis to include more patient samples and other types of NF1-derived tumors. As an orphan disease, NF1 has been poorly characterized compared to more common cancers. To rectify this, the Children's Tumor Foundation and Sage Bionetworks are collaborating to make NF1 data available to the public to accelerate research and the drug discovery pipeline. We expect that this data will be a resource for other NF1 researchers to assist in the study of this disease at the molecular level. All data and preliminary results are publicly available at http://www.synapse.org/dermalNF

Citation Format: Sara JC Gosline, Pamela Knight, Thomas Yu, Nripesh Prasad, Angela Jones, Shristi Shrestha, Braden Boone, Shawn E. Levy, Andrew J. Link, Allison C. Galassie, Hubert Weinberg, Stephen Friend, Salvatore La Rosa, Justin Guinney, Annette Bakker. The molecular landscape of dermal neurofibromatosis. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 772.

Neurofibromatosis as a gateway to better treatment for a variety of malignancies

The neurofibromatoses (NF) are a group of rare genetic disorders that can affect all races equally at an incidence from 1:3000 (NF1) to a log unit lower for NF2 and schwannomatosis. Since the research community is reporting an increasing number of malignant cancers that carry mutations in the NF genes, the general interest of both the research and pharma community is increasing and the authors saw an opportunity to present a novel, fresh approach to drug discovery in NF. The aim of the paper is to challenge the current drug discovery approach to NF, whereby existing targeted therapies that are either in the clinic or on the market for other disease indications are repurposed for NF. We offer a suggestion for an alternative drug discovery approach. In the new approach, selective and tolerable targeted therapies would be developed for NF and later expanded to patients with more complex diseases such as malignant cancer in which the NF downstream pathways are deregulated. The Children's Tumor Foundation, together with some other major NF funders, is playing a key role in funding critical initiatives that will accelerate the development of better targeted therapies for NF patients, while these novel, innovative treatments could potentially be beneficial to molecularly characterized cancer patients in which NF mutations have been identified.

Abstract A32: Gaps and opportunities for RASopathies: Use of new tools to make the right choice in target and compound selection

“RASopathies” are a class of developmental disorders caused by germline mutations in genes that encode protein components of the Ras/MAPK pathway. Each syndrome exhibits different phenotypic features, though there are many overlapping features among syndromes, including characteristic facial features, cardiac defects, cutaneous abnormalities, autism, learning disabilities and a predisposition to malignancies. Neurofibromatosis type 1 (NF1) has been more extensively studied than the other syndromes and today 11 clinical trials are ongoing for NF1 versus 3 in all other RASopathies.

In the last couple of years a few studies were published which directly connected the molecular mechanisms of these diseases to each other, creating a new opportunity to cross-validate the effects of modulating the RAS pathway at different stages and with different tools, and providing new overlapping strategies which could also benefit less studied syndromes. We recently acquired in-house capabilities to access MetaCore and Integrity databases to help in the process of data mining and compound selection. We applied these capabilities in a multi-tiered approach to compare NF1 with Noonan Syndrome (NS). First, we analyzed the molecular profiles of these two RASopathies using MetaCore and zeroed in on a well-known common molecular target, MEK. Among the large number of MEK inhibitors now in development, an analysis of these agents has been made with the use of the database to compare the different chemical classes of inhibitors and analyse properties, opportunities and redundancies among these compounds. The same approach will be then applied to try to identify a novel drug target in common in NF1 and NS. For this new target, an analysis of available drugs will be made to try to identify the best candidate/s which could be explored for in vitro or in vivo testing or as a proof-of-concept. Combining the capabilities of bioinformatic analysis and chemical analysis, a more informed drug choice for screening and/or preclinical testing can be done on the basis of detailed information on drugs and interconnections of targets/pathways. This approach, taking into account the various aspects of a particular model or disease, will attempt to accelerate research by allowing the selection of the most suitable compounds for a particular experiment, allowing for more informed choices.

Citation Format: Salvatore La Rosa, Pamela Knight, Patrice Pancza, Kimberly Scobie, Annette Bakker. Gaps and opportunities for RASopathies: Use of new tools to make the right choice in target and compound selection. [abstract]. In: Proceedings of the AACR Special Conference on RAS Oncogenes: From Biology to Therapy; Feb 24-27, 2014; Lake Buena Vista, FL. Philadelphia (PA): AACR; Mol Cancer Res 2014;12(12 Suppl):Abstract nr A32. doi: 10.1158/1557-3125.RASONC14-A32

cDNA cloning and substrate specificity of equine tryptase, a possible mediator in equine heaves

BACKGROUND

Mast cell mediators are believed to play a central role in inflammatory lung disorders such as human allergic and occupational asthma. Equine heaves is characterized by reversible neutrophilic airway inflammation and airway obstruction, primarily due to bronchospasm and mucus hypersecretion, following exposure of susceptible horses to organic stable dusts. As such, heaves shares many similarities with human occupational dust-induced asthma and therefore it is proposed that mast cells may also be implicated in the pathogenesis of heaves. Tryptase, a mast cell-specific proteinase, can be used as an indicator of biological mast cell activity.

OBJECTIVE

The aim of this study was to determine the cDNA sequence of equine tryptase and to investigate its substrate specificity in order to rationalize its enzymatic activity.

METHODS

RT-PCR cloning was used to sequence equine tryptase. Substrate specificity of equine tryptase was investigated using arginine and lysine containing substrates.

RESULTS

The cDNA and deduced amino acid (Aa) sequences for equine tryptase shared strong identity with other tryptases. Unusually for a trypsin-like proteinase however, equine tryptase has alanine at residue 216, rather than glycine, which confers increased arginine substrate specificity in vitro and may restrict fibrinogenolysis in vivo.

CONCLUSION

Cloning and sequencing of the mast cell proteinase equine tryptase will allow molecular probing of its expression in the lung of control and heaves-affected horses. Further work is warranted to determine the biological relevance of the unique alanine 216 substitution in the molecular sequence of the equine tryptase substrate-binding pocket.

Treatment and postrelease rehabilitative programs for juvenile offenders

The juvenile justice system has become notably aware of the increasing use of postrelease rehabilitative treatment interventions for offenders. In many instances, juvenile justice systems are required to ensure that core treatment needs of youth are met. As a result of the heightened awareness of the need for postrelease rehabilitation treatment programs, many researchers and providers are calling for more systematic approaches to offender treatment. This article summarizes a body of literature on juvenile offenders who have specialized postrelease rehabilitative treatment needs. It reviews cognitive-behavioral theoretical models and core postrelease treatment strategies. It presents a review of youth who have specialized needs in light of postrelease practices, describes several model postrelease rehabilitation programs, and reviews outcomes of these programs.

Alterations in grip strength during male sexual arousal

Although it is known that alterations in grip strength occur under a number of conditions, little is known about relationships between grip strength and sexual arousal. This relationship was investigated in 30 healthy heterosexual males, who viewed both erotic and nonerotic videos. A questionnaire was used to assess the extent of sexual arousal. The grip strengths of both hands were measured with a five-position (P1-P5) dynamometer, before and after watching the videos. After watching the erotic video, there was a statistically significant reduction in grip strength for the P2 position, with nonsignificant overall reductions in grip strength for all other positions tested. No such effect was observed in control tests. The results indicate that during sexual arousal, the neural system is likely to reduce the output to muscles not directly related to sexual function, presumably to enhance the physiological responses of sexual arousal.

Mast cell protease 5 mediates ischemia-reperfusion injury of mouse skeletal muscle

Ischemia with subsequent reperfusion (IR) injury is a significant clinical problem that occurs after physical and surgical trauma, myocardial infarction, and organ transplantation. IR injury of mouse skeletal muscle depends on the presence of both natural IgM and an intact C pathway. Disruption of the skeletal muscle architecture and permeability also requires mast cell (MC) participation, as revealed by the fact that IR injury is markedly reduced in c-kit defective, MC-deficient mouse strains. In this study, we sought to identify the pathobiologic MC products expressed in IR injury using transgenic mouse strains with normal MC development, except for the lack of a particular MC-derived mediator. Histologic analysis of skeletal muscle from BALB/c and C57BL/6 mice revealed a strong positive correlation (R(2) = 0.85) between the extent of IR injury and the level of MC degranulation. Linkage between C activation and MC degranulation was demonstrated in mice lacking C4, in which only limited MC degranulation and muscle injury were apparent. No reduction in injury was observed in transgenic mice lacking leukotriene C(4) synthase, hemopoietic PGD(2) synthase, N-deacetylase/N-sulfotransferase-2 (enzyme involved in heparin biosynthesis), or mouse MC protease (mMCP) 1. In contrast, muscle injury was significantly attenuated in mMCP-5-null mice. The MCs that reside in skeletal muscle contain abundant amounts of mMCP-5 which is the serine protease that is most similar in sequence to human MC chymase. We now report a cytotoxic activity associated with a MC-specific protease and demonstrate that mMCP-5 is critical for irreversible IR injury of skeletal muscle.

An investigation of the components of best nursing practice in the care of acutely ill hospitalized older patients with coincidental dementia: a multi-method design

The main aim of this study was to examine, from the consumer's perspective, the components of best nursing practice in the care of acutely ill hospitalized elderly people who coincidentally suffered from dementia. Due to the complexity of the problem under investigation a triangulated design was formulated. This design comprised survey methodology, audit and critical incident technique. Data derived from each of these approaches were analysed first in isolation and subsequently combined at a conceptual level. The sample comprised 213 people aged 65 years and older, who were consecutive admissions from two acute medical and two acute care of elderly people wards. Sixty-six per cent of these individuals were found to suffer from cognitive impairment, 40% experiencing severe problems. The documentary survey revealed that patients with normal or severely abnormal cognitive functioning were more likely to have this noted than those with mild-moderate levels of impairment. No evidence of formal assessment was located and only 15% of these patients had items included in their nursing care plans associated with their chronic confusion. A sub-sample of 41 chronically confused people and their main hospital visitor were invited to participate in critical incident interviews. These conversations led to the identification of four major themes which reflected the most valued aspects of the nursing care which had been received or observed. The relationship between documentary care scores and the proportion of positive descriptions of care within each of the four themes was explored. The findings indicate that acute nursing care is deemed only to be at its best when it is delivered in tandem with dementia care. Discrete areas for practice development are identified and standards to guide nursing care are proposed. In addition to the practice development issues raised by the work, the methodological lessons further advance the practice of multi-method research.

Determination of emamectin benzoate in medicated fish feed

A method was developed to quantitate emamectin benzoate in fish feed at levels between 5 and 15 ppm. The active ingredient is extracted from 20 g medicated feed into aqueous-methanolic solvent by overnight shaking. A solid-phase extraction procedure using a 2 g C18 cartridge is then used to concentrate the active residue and remove interfering matrix components. The extracted drug and internal standard are eluted from the cartridge, evaporated to dryness, and reconstituted in methanol. A control feed sample and fortified control working standard are simultaneously prepared. Remaining interferences and sample analysis are further separated on a gradient liquid chromatographic system. Recovery of emamectin benzoate from fortified feeds ranged from 97 to 100%, with a coefficient of variation (CV) of 1.2%. Determination of emamectin benzoate in medicated feeds resulted in CVs ranging from 2.3 to 4.2% and recoveries of 88 to 98% of label claim.

Implications for space radiation environment models from CREAM & CREDO measurements over half a solar cycle

Flight data obtained between 1990 and 1997 from the Cosmic Radiation Environment Monitors CREAM & CREDO carried on UoSAT-3, Space Shuttle, STRV-1a (Space Technology Research Vehicle) and APEX (Advanced Photovoltaic and Electronics Experiment Spacecraft) provide coverage over half a solar cycle. The modulation of cosmic rays and evolution of the South Atlantic Anomaly are observed, the former comprising a factor of three increase at high latitudes and the latter a general increase accompanied by a north-westward drift. Comparison of particle fluxes and linear energy transfer (LET) spectra is made with improved environment & radiation transport calculations which account for shield distributions and secondary particles. While there is an encouraging convergence between predictions and observations, significant improvements are still required, particularly in the treatment of locally produced secondary particles. Solar-particle events during this time period have LET spectra significantly below the October 1989 event which has been proposed as a worst case model.

Evaluation of recombinant sporozoite antigen SPAG-1 as a vaccine candidate against Theileria annulata by the use of different delivery systems

The major sporozoite surface antigen of Theileria annulata (SPAG-1) is a candidate for inclusion in a subunit vaccine. In this paper we summarize the results of 4 vaccination experiments using recombinant SPAG-1 expressed in different systems and presented in different adjuvants. The antigen has been presented as either a C terminal 108 amino acid peptide (called SR1) expressed as both beta-galactosidase and hepatitis B core antigen fusions or as a full-length form expressed as a GST fusion with an N terminal His6 tag. We used different adjuvants, namely Freund's, saponin, ISCOMs and a proprietary adjuvant supplied by SmithKline Beecham, which we call SKBA. The data point to the conclusion that SPAG-1 can elicit partial protection and is therefore suitable for inclusion in an eventual multicomponent subunit vaccine.

Ellipticity and pulse shape dependence of localised wavepackets

Atoms in intense, high-frequency laser fields exhibit the remarkable property that they can be stable against ionization. We investigate the structure of stabilized wavepackets for a two-dimensional model hydrogen atom interacting with an intense, high frequency laser pulse as a function of the laser pulse ellipticity and laser pulse rise-time. The computed wavepackets are compared with the corresponding Kramers-Henneberger (K-H) ground states. Laser pulse turn-on effects are studied by contrasting the structure of the localized part of the wavepackets and the ionizing part of the wavepackets for three different ellipticities and for various pulse turn-on times.