Protocol for a living systematic review for the management of concussion in adults

INTRODUCTION

Concussion/mild traumatic brain injury (mTBI) often presents initially with disabling symptoms that resolve, but for an unfortunate minority some of these symptoms may become prolonged. Although research into diagnosis and interventions for concussion is increasing, study quality overall remains low. A living systematic review that is updated as evidence becomes available is the ideal research activity to inform a living guideline targeting clinicians and patients. The purpose of this paper is to present the protocol of an ongoing living systematic review for the management of adult concussion that will inform living guidelines building off the Guideline for Concussion/Mild Traumatic Brain Injury and Persistent Symptoms: third Edition.

METHODS AND ANALYSIS

The Preferred Reporting Items for Systematic Review and Meta-Analysis Protocol guidelines were followed in the reporting of this systematic review protocol. We are including English peer-reviewed observational studies, trials, qualitative studies, systematic reviews and clinical practice guidelines related to diagnosis/assessment or treatment of adult concussion. Future searches will be conducted at minimum every 6 months using the following databases: MEDLINE ALL, EMBASE, Cochrane, PsycInfo and CINAHL. The data are managed in the Covidence website. Screening, data extraction and risk-of-bias assessments are being done through multiple raters working independently. Multiple validated tools are being used to assess risk of bias, and the tool applied matches the document or study design (eg, Downs and Black Scale for healthcare interventions). Many concussion experts in various clinical disciplines from across North America have volunteered to examine the evidence in order to make recommendations for the living guidelines.

ETHICS AND DISSEMINATION

No ethical approval is necessary because primary data are not collected. The results will be disseminated through peer-reviewed publications and on the living guidelines website once built.

PROSPERO REGISTRATION NUMBER

CRD42022301786.

Treatment Adherence in Integrative Medicine-Part One: Review of Literature

Treatment adherence is a topic that is well studied but not well understood. Low treatment adherence is a significant issue that limits the effective management and treatment of chronic conditions, creating significant health care burden, costs, and poor patient outcomes. This report provides a review of the factors that facilitate or create barriers to treatment adherence, as well as strategies recommended to overcome adherence barriers. A total of 25 interviews were conducted with practitioners demonstrating both high (n = 16) and low (n = 9) treatment adherence rates. A total of 185 survey responses were received from high-treatment adherence rate practitioners (n = 21), low-treatment adherence rate practitioners (n = 83), and practitioners that were neither in the high- or low-treatment adherence rate range (n = 81). Practitioner prescribing behaviors and adherence statistics were determined and stratified by high-treatment adherence rate and low-treatment adherence rate practitioners. From the interviews, 78% of low-rate practitioners mentioned that establishing trust is a primary best practice for optimizing adherence, and for high-rate practitioners, 69% thought that facilitating trust was important to optimizing adherence. Both low- and high-adherence rate practitioners prioritized using a staged approach as a strategy to overcome barriers to adherence. From the total survey sample it was found that key strategies to improving adherence included the practice of booking follow-up appointments, using lab results to explain treatment plans, and using a staged approach for treatment plans. Our research sought to elicit strategies and skills that can help improve treatment adherence in integrative medicine and our findings have identified several common practices that can help to improve adherence. Research taking advantage of mobile devices and the internet for adherence has started to expand within the last 10 to 15 years. Technology has the potential to lead the development and establishment of a centralized database that acquires adherence information and provides solutions to its practitioners and patients. Further work to advance the field of integrative medicine through additional research and interventions that support treatment adherence would be valuable to the effective treatment and management of integrative medicine patients.

Treatment Adherence in Integrative Medicine-Part Two: Practitioner Insights

Treatment adherence is a topic that is well studied but not well understood. Low treatment adherence is a significant issue that limits the effective management and treatment of chronic conditions, creating significant health care burden, costs, and poor patient outcomes. This report provides a review of the factors that facilitate or create barriers to treatment adherence, as well as strategies recommended to overcome adherence barriers. A total of 25 interviews were conducted with practitioners demonstrating both high (n = 16) and low (n = 9) treatment adherence rates. A total of 185 survey responses were received from high-treatment adherence rate practitioners (n = 21), low-treatment adherence rate practitioners (n = 83), and practitioners that were neither in the high- or low-treatment adherence rate range (n = 81). Practitioner prescribing behaviors and adherence statistics were determined and stratified by high-treatment adherence rate and low-treatment adherence rate practitioners. From the interviews, 78% of low-rate practitioners mentioned that establishing trust is a primary best practice for optimizing adherence, and for high-rate practitioners, 69% thought that facilitating trust was important to optimizing adherence. Both low-and high-adherence rate practitioners prioritized using a staged approach as a strategy to overcome barriers to adherence. From the total survey sample it was found that key strategies to improving adherence included the practice of booking follow-up appointments, using lab results to explain treatment plans, and using a staged approach for treatment plans. Our research sought to elicit strategies and skills that can help improve treatment adherence in integrative medicine and our findings have identified several common practices that can help to improve adherence. Research taking advantage of mobile devices and the internet for adherence has started to expand within the last 10 to 15 years. Technology has the potential to lead the development and establishment of a centralized database that acquires adherence information and provides solutions to its practitioners and patients. Further work to advance the field of integrative medicine through additional research and interventions that support treatment adherence would be valuable to the effective treatment and management of integrative medicine patients.

Thromboprophylaxis practice patterns and beliefs among physicians treating patients with abdominopelvic cancers at a Canadian centre

Background

There is inadequate high-quality evidence on thromboprophylaxis for patients undergoing surgery for abdominopelvic cancer. We surveyed physicians who treat patients with abdominopelvic cancer to determine current thromboprophylaxis practice patterns and to determine where research is needed.

Methods

We created an online survey with questions on thromboprophylaxis topics, including type of thromboprophylaxis used, timing of initial thromboprophylaxis dose, use of thromboprophylaxis during chemotherapy, use of extended-duration thromboprophylaxis and areas for future research. The survey questions were reviewed by external content experts to ensure they were appropriate and relevant. Surgeons, thrombosis experts and medical oncologists who manage patients with abdominopelvic cancers at 1 large Canadian academic centre were invited to complete the survey between January and April 2019.

Results

Of the 57 physicians invited, 42 (74%) completed the survey, including 27 surgeons (response rate 79%), 9 thrombosis experts (response rate 75%) and 6 medical oncologists (response rate 55%). Most surgeons (22 [82%]) reported using mechanical thromboprophylaxis, whereas only 1 thrombosis expert (11%) recommended mechanical thromboprophylaxis. There was substantial variability in the timing of the initial dose of thromboprophylaxis, with 9/10 urologists (90%) and all 7 general surgeons giving the first dose intraoperatively, and three-quarters of thoracic surgeons (3/4 [75%]), gynecologists (3/4 [75%]) and thrombosis experts (7/9 [78%]) starting thromboprophylaxis after surgery. All medical oncologists believed chemotherapy increases the risk of venous thromboembolism, but 4 (67%) reported that they do not routinely prescribe thromboprophylaxis owing to bleeding concerns. Most respondents (35/38 [92%]) felt there was a need for more research on thromboprophylaxis and indicated willingness to participate in future clinical trials.

Conclusion

Variability exists in contemporary thromboprophylaxis practice patterns among physicians treating patients with abdominopelvic cancer. Future research is needed to standardize care and improve outcomes for patients.

Shared decision-making for the management of small renal masses: Development and acceptability testing of a novel patient decision aid

INTRODUCTION

Shared decision-making incorporates patients' values and preferences to achieve high-quality decisions. The objective of this study was to develop an acceptable patient decision aid to facilitate shared decision-making for the management of small renal masses (SRMs).

METHODS

The International Patient Decision Aids Standards were used to guide an evidence-based development process. Management options included active surveillance, thermal ablation, partial nephrectomy, and radical nephrectomy. A literature review was performed to provide incidence rates for outcomes of each option. Once a prototype was complete, alpha-testing was performed using a 10-question survey to assess acceptability with patients, patient advocates, urologists, and methodological experts. The primary outcome was acceptability of the decision aid.

RESULTS

A novel patient decision aid was created to facilitate shared decision-making for the management of SRMs. Acceptability testing was performed with 20 patients, 10 urologists, two patient advocates, and one methodological expert. Responders indicated the decision aid was appropriate in length (82%, 27/33), well-balanced (82%, 27/33), and had language that was easy to follow (94%, 31/33). All patient responders felt the decision aid would have been helpful during their consultation and would recommend the decision aid for future patients (100%, 20/20). Most urologists reported they intend to use the decision aid (90%, 9/10).

CONCLUSIONS

A novel patient decision aid was created to facilitate shared decision-making for management of SRMs. This clinical tool was acceptable with patients, patient advocates, and urologists and is freely available at: https://decisionaid.ohri.ca/decaids.html.

A novel prevention bundle to reduce incisional infections after radical cystectomy

PURPOSE

Our institution implemented a novel intervention bundle to reduce incisional surgical site infections (SSIs) for patients undergoing radical cystectomy. The primary objective of this study was to evaluate the efficacy of the bundle in reducing incisional SSIs post-cystectomy.

MATERIAL AND METHODS

A before-after cohort study was performed on all patients who underwent radical cystectomy by urologic oncologists at The Ottawa Hospital from January 2016 to March 2019. Thirty-day postoperative incisional SSIs were identified from the medical record and were compared to institutionally collected National Surgical Quality Improvement Program data. The SSI reduction strategy was implemented as of March 1st, 2018. Adjusted associations between the SSI intervention with the risk of incisional SSI were determined. Cystectomy incisional SSI rates were compared to all other National Surgical Quality Improvement Program-collected surgeries at The Ottawa Hospital during the same time period.

RESULTS

One hundred and thirty-two patients were included; 41 following implementation of the SSI reduction bundle. Mean age was 69 years, 104 (79%) were male, and 59 (45%) received neobladders. The risk of incisional SSI decreased from 16.5% preintervention to 2.4% post intervention (risk ratio 0.17; P = 0.004). Intraoperative transfusion and diabetes were independently associated with an increased risk of incisional SSI (P < 0.05). The SSI rate for all other surgical procedures at our institution remained stable during the same time period.

CONCLUSIONS

The risk of SSI after radical cystectomy is high. Use of an SSI reduction bundle was associated with a large reduction in incisional SSIs. Further evaluation of this intervention in other centers is warranted.

Derivation and validation of text search algorithms for renal and adrenal lesion identification in radiology text reports

INTRODUCTION

Most cohort studies are limited by sampling and accrual bias. The capability to detect specific lesions identified in radiological text reports could eliminate these biases and benefit patient care, clinical research, and trial recruitment. This study derived and internally validated text search algorithms to identify four common urological lesions (solid renal masses, complex renal cysts, adrenal masses, and simple renal cysts) using radiology text reports.

METHODS

A simple random sample of 10 000 abdominal ultrasound (US) and computed tomography (CT) reports was drawn from our hospital's data warehouse. Reports were manually reviewed to determine the true status of the four lesions. Using commonly available software, we created logistic regression models having as predictors the status of a priori selected text terms in the report. We used bootstrap sampling with 95^th percentile thresholds to select variables for the final models, which were modified into point systems. A second independent, random sample of 2855 reports, stratified by the number of points for each abnormality, was reviewed in a blinded fashion to measure the accuracy of each lesion's point system.

RESULTS

The prevalence of solid renal mass, complex renal cyst, adrenal mass, and simple renal cyst, was 2.0%, 1.7%, 3.2%, and 20.0%, respectively. Each model contained between one and five text terms with c-statistics ranging between 0.66 and 0.90. In the independent validation, the scoring systems accurately predicted the probability that a text report cited the four lesions.

CONCLUSIONS

Textual radiology reports can be analyzed using common statistical software to accurately determine the probability that important abnormalities of the kidneys or adrenal glands exist. These methods can be used for case identification or epidemiological studies.

Development and acceptability testing of a patient decision aid for individuals with localized renal masses considering surgical removal with partial or radical nephrectomy

INTRODUCTION

Patient decision aids are structured clinical tools that facilitate shared decision-making. In urology, the decision between partial and radical nephrectomy for a renal mass can be difficult. We sought to develop and evaluate a decision aid for patients with a localized renal mass considering surgery. This paper describes the development process and acceptability testing of our patient decision aid.

MATERIAL AND METHODS

A decision aid was systematically created using the International Patient Decision Aids Standards. Review of the literature identified evidence regarding patient-important outcomes of partial and radical nephrectomy. A mixed methods survey was designed to assess acceptability of the decision aid. Kidney cancer survivors, patient advocates, methodological experts, and urologists were recruited to evaluate the decision aid. The primary outcome was the acceptability of the decision aid reported by survey responders.

RESULTS

An evidence-based decision aid was created. Included benefits were overall survival, cancer-free survival, and length of hospital stay. Included harms were postoperative bleeding, urine leak, stage 3 renal failure, renal replacement therapy, and flank bulge. The decision aid met the International Patient Decision Aids Standards defining (6 of 6), certification (6 of 6), and quality criteria (21 of 23). Results of acceptability testing were highly favorable. Responders (n = 22) reported the decision aid had acceptable language (91%), an appropriate length (82%), and presented balanced options (91%). Nine of 11 urologists (82%) reported intended use with future patients.

CONCLUSIONS

A novel, evidence-based decision aid was created for patients with renal masses considering surgery. The decision aid is available at https://decisionaid.ohri.ca/AZsumm.php?ID=1913. A separate decision aid addressing the management of small renal masses is currently under development.

Venous thromboembolism and transfusion after major abdominopelvic surgery

BACKGROUND

Thromboprophylaxis aims to reduce venous thromboembolism but has the potential to increase bleeding. We sought to evaluate the risk of venous thromboembolism and transfusion after major abdominopelvic procedures and to quantify the association of the procedure with venous thromboembolism.

METHODS

The American College of Surgeons' National Surgical Quality Improvement Program was queried for patients who received an abdominopelvic surgery between 2005 and 2016. Patient factors, operative factors, and outcomes were collected. Multivariable analyses were used to determine the association between individual procedures and venous thromboembolism. Area under the curve analyses were performed to assess whether addition of the procedure to Caprini score improved the association of the model with venous thromboembolism. The primary outcome was risk of venous thromboembolism within 30 days of surgery. Secondary outcomes were the risk of transfusion within 30 days and the association between operative time with venous thromboembolism.

RESULTS

There were 896,441 patients who received an abdominopelvic procedure. The overall risk of venous thromboembolism was 1.9% (n = 16,665). Procedures with the highest risk of venous thromboembolism were esophagectomy (5.5%) and partial esophagectomy (5.3%). The overall risk of transfusion was 9.5% (n = 84,889). Procedures with the highest risk of transfusion were pelvic exenteration (53.6%) and radical cystectomy (37.7%). On multivariable analyses, individual procedures were independently associated with venous thromboembolism, despite adjusting for Caprini score. Area under the curve analyses indicated risk prediction of the baseline model (area under the curve 0.59) improved when procedures were added (area under the curve 0.68).

CONCLUSION

Patients undergoing abdominopelvic surgery are at a high risk of venous thromboembolism and transfusion. Improved risk stratification may be possible by including more procedural information in scoring systems.

Development and Implementation of a Continuing Medical Education Program in Canada: Knowledge Translation for Renal Cell Carcinoma (KT4RCC)

An in-person multidisciplinary continuing medical education (CME) program was designed to address previously identified knowledge gaps regarding quality indicators of care in kidney cancer. The objective of this study was to develop a CME program and determine if the program was effective for improving participant knowledge. CME programs for clinicians were delivered by local experts (uro-oncologist and medical oncologist) in four Canadian cities. Participants completed knowledge assessment tests pre-CME, immediately post-CME, and 3-month post-CME. Test questions were related to topics covered in the CME program including prognostic factors for advanced disease, surgery for advanced disease, indications for hereditary screening, systemic therapy, and management of small renal masses. Fifty-two participants attended the CME program and completed the pre- and immediate post-CME tests. Participants attended in Ottawa (14; 27%), Toronto (13; 25%), Québec City (18; 35%), and Montréal (7; 13%) and were staff urologists (21; 40%), staff medical oncologists (9; 17%), fellows (5; 10%), residents (16; 31%), and oncology nurses (1; 2%). The mean pre-CME test score was 61% and the mean post-CME test score was 70% (p = 0.003). Twenty-one participants (40%) completed the 3-month post-CME test. Of those that completed the post-test, scores remained 10% higher than the pre-test (p value 0.01). Variability in test scores was observed across sites and between French and English test versions. Urologists had the largest specialty-specific increase in knowledge at 13.8% (SD 24.2, p value 0.02). The kidney cancer CME program was moderately effective in improving provider knowledge regarding quality indicators of kidney cancer care. These findings support continued use of this CME program at other sites.

Naturopathy Special Interest Group Research Capacity and Needs Assessment Survey

Objectives: Despite recent shifts in regulation and recognition of the role that naturopathy plays in health care delivery in Canada, comparatively little research has been conducted regarding individuals who conduct naturopathy-related research. A survey was undertaken to better understand the needs and capacity of these individuals to conduct more research.

Design, Setting, and Subjects: The Naturopathy Special Interest Group (N-SIG) of the Interdisciplinary Network of Complementary and Alternative Medicine (INCAM) Researchers created and distributed a survey of individuals interested in naturopathy-related research to assess gaps between current and desired research activity and needs for further participation.

Outcome measures: Results from a previous pilot study (2014; n = 58) were used to inform the design and distribution. This study received approval and oversight from the Research Ethics Board of the Canadian College of Naturopathic Medicine.

Results: The survey was completed by 201 individuals (∼5%–10% of all naturopathic doctors and naturopathy researchers in Canada). The majority (70%) had no peer-reviewed publication experience; however, 63% reported having published in a nonpeer-reviewed medium. Respondents reported differing levels of confidence in completing various components of a research project. Frequently selected obstacles included lack of time due to professional and personal obligations, as well as insufficient training, funding, and mentorship. The greatest identified needs for participation in research were mentorship/support, access to a wider degree of scientific journals, and targeted funding opportunities for CAM research. Overall, the results of this survey suggest that there is interest in further conducting naturopathy-related research in Canada. There are individuals who are already involved and have expressed skills in the area of evidence-based medicine. Mentorship, research training, resources, and critical appraisal and writing skills may be important leverage points.

Conclusion: Findings from this investigation will be used to inform an agenda for naturopathy-related research and activities of the N-SIG with respect to enhancing research capacity. Other CAM groups or geographic regions could consider using similar methodology to assess capacity and needs for research participation.

Reducing overtreatment of prostate cancer by radical prostatectomy in Eastern Ontario: a population-based cohort study

BACKGROUND

Canadian guidelines recommend against population-based screening for prostate cancer because of the risk of overdiagnosis and overtreatment. We sought to assess whether a higher proportion of patients receiving surgery had clinically significant cancer over time.

METHODS

All hospitals in Eastern Ontario that perform prostatectomy participate in a Prostate Cancer Community of Practice, which prospectively maintains a database for the region. Using these data, we conducted a retrospective cohort study that included all patients who underwent prostatectomy from 2009 to 2015 in the region. We examined trends in biopsy findings, clinical stage, prostate-specific antigen level and Gleason score. We then determined whether the proportion of patients with clinically significant cancer (Gleason score ≥ 7 or stage pT3) increased over time.

RESULTS

During the study period, 1897 patients underwent prostatectomy in Eastern Ontario (mean 271 surgeries/yr). The proportion of patients who were determined to have National Comprehensive Cancer Network intermediate or high-risk disease increased from 46.7% in 2009 to 90.2% in 2015. The proportion of men with clinically significant cancer on prostatectomy increased from 59.7% in 2009 to 93.1% in 2015. Adjusted analyses suggested that the proportion of patients with clinically significant cancer increased by 5% per year during the study period.

INTERPRETATION

There has been a change in the tumour characteristics of patients who undergo prostatectomy in Eastern Ontario. In recent years, almost all patients have had clinically significant cancer, which suggests that overtreatment of prostate cancer has decreased.

Age-stratified perioperative mortality after urological surgeries

INTRODUCTION

More elderly patients are presenting for surgical consultation. Understanding the risk of mortality by age group after urological surgery is important for patient selection and counselling.

METHODS

A historical cohort study of The American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database from 2006-2015 was performed. Current procedural terminology (CPT) codes for similar surgical procedures were grouped for analyses. Urological procedures commonly performed in elderly patients were identified and stratified by patient age and surgical approach (open vs. laparoscopic/robotic). The primary outcome was the absolute risk of death by 30 days stratified by age for each surgical procedure. The secondary outcome was risk of death by surgical approach (open vs. laparoscopic/robotic).

RESULTS

Twelve urological procedures were reviewed including 124 262 patients. A total of 1011 (0.8%) deaths occurred by 30 days after surgery. The procedure with the highest incidence of mortality by 30 days was open nephroureterectomy (2.9 %). In patients 80 years and over, the procedure with the highest incidence of death was open radical nephrectomy (5.32%). There was an increased risk of mortality with increasing age group for all procedures. Unadjusted risk of mortality was consistently higher in patients who receive open compared to laparoscopic surgery.

CONCLUSIONS

There is an increasing risk of mortality with age and with open surgical approach in urology. Knowledge regarding the absolute risk of mortality in patients receiving common urological surgeries may improve patient selection and counselling.

Fish-Derived Omega-3 Fatty Acids and Prostate Cancer: A Systematic Review

BACKGROUND

The use of natural health products in prostate cancer (PrCa) is high despite a lack of evidence with respect to safety and efficacy. Fish-derived omega-3 fatty acids possess anti-inflammatory effects and preclinical data suggest a protective effect on PrCa incidence and progression; however, human studies have yielded conflicting results.

METHODS

A search of OVID MEDLINE, Pre-MEDLINE, Embase, and the Allied and Complementary Medicine Database (AMED) was completed for human interventional or observational data assessing the safety and efficacy of fish-derived omega-3 fatty acids in the incidence and progression of PrCa.

RESULTS

Of 1776 citations screened, 54 publications reporting on 44 studies were included for review and analysis: 4 reports of 3 randomized controlled trials, 1 nonrandomized clinical trial, 20 reports of 14 cohort studies, 26 reports of 23 case-control studies, and 3 case-cohort studies. The interventional studies using fish oil supplements in patients with PrCa showed no impact on prostate-specific antigen levels; however, 2 studies showed a decrease in inflammatory or other cancer markers. A small number of mild adverse events were reported and interactions with other interventions were not assessed. Cohort and case-control studies assessing the relationship between dietary fish intake and the risk of PrCa were equivocal. Cohort studies assessing the risk of PrCa mortality suggested an association between higher intake of fish and decreased risk of prostate cancer-related death.

CONCLUSIONS

Current evidence is insufficient to suggest a relationship between fish-derived omega-3 fatty acid and risk of PrCa. An association between higher omega-3 intake and decreased PrCa mortality may be present but more research is needed. More intervention trials or observational studies with precisely measured exposure are needed to assess the impact of fish oil supplements and dietary fish-derived omega-3 fatty acid intake on safety, PrCa incidence, treatment, and progression.

Zinc supplementation does not alter sensitive biomarkers of copper status in healthy boys

The tolerable upper intake levels (UL) for zinc for children were based on limited data and there is concern that the UL may be set too low. The first effect of excessive zinc intake is a reduction in copper status. The primary objective of this study was to examine the effect of zinc supplementation on copper status in children. Healthy, 6- to 8-y-old boys from Ontario, Canada were assigned to take a placebo (n = 10) or 5 mg (n = 10), 10 mg (n = 9), or 15 mg (n = 8) of zinc supplement daily for 4 mo in a double-blinded, placebo-controlled, randomized trial. Biochemical measures were evaluated at baseline and after 2 and 4 mo of supplementation. Food records were completed near the baseline and 4-mo visits. Age and anthropometric measurements did not differ (P > 0.05) between treatment groups at baseline. Mean zinc intakes from food alone (10.9-14.8 mg zinc/d) approached or exceeded the UL of 12 mg/d. Compared with the placebo group, the zinc groups had a greater change in the urine zinc:creatinine ratio at 4 mo (P = 0.02). Traditional (plasma copper and ceruloplasmin activity) and more sensitive biomarkers of copper status, including erythrocyte SOD1 activity and the erythrocyte CCS:SOD1 protein ratio, were unchanged in zinc-supplemented boys, demonstrating that copper status was not depressed. Serum lipid measures and hemoglobin concentrations were also unaffected and gastrointestinal symptoms were not reported. These data provide evidence in support of the need for reexamining the current UL for zinc for children.

Acute lung injury induced by Pseudomonas aeruginosa elastase in hamsters

Human neutrophil elastase (HNE) is the predominant elastolytic enzyme in the sputum of cystic fibrosis (CF) patients. However, a variably small portion of the activity can be ascribed to Pseudomonas aeruginosa elastase (PaE). The purpose of these studies was to evaluate the activities of the two elastases in an in vivo model of acute lung injury (ALI). The elastolytic activity of Pseudomonas aeruginosa elastase (MW = 39K) and human neutrophil elastase (MW = 33K) were also examined using insoluble bovine neck and lung elastin. The ability of hamster serum to inhibit elastinolysis by the two elastases was also examined. On a per milligram protein basis, PaE was the more potent elastase, regardless of substrate, and it preferentially hydrolyzed lung relative to neck elastin. PaE is poorly inhibited by hamster serum compared to HNE. In vivo, PaE is much more efficient than HNE in inducing an acute lung injury in hamsters. The duration of effects induced by doses of the two proteases that produce similar acute biological effects are essentially identical. The increases of lung weight and total lavagable WBCs persist for at least 7 days. All other parameters return to baseline between 3 and 5 days. The predominant cells in the lavage 1 and 2 days post insult are PMNs. By day 7, the predominant cell is the macrophage. These data suggest that even though PaE is a minor component of the elastolytic activity in CF patients, it may still contribute significantly to the pathology of the disease.

Biologic characterization of ICI 200,880 and ICI 200,355, novel inhibitors of human neutrophil elastase

ICI 200,880 and its close structural analog, ICI 200,355, are representatives of a new chemical class of inhibitors of human neutrophil elastase (HNE). Both compounds are substituted tripeptide ketones, which demonstrated competitive kinetics versus HNE, with identical Ki values of 5.0 x 10(-10) M. The selectivity of ICI 200,880 for HNE versus a variety of enzymes ranged from 150-fold [relative to porcine pancreatic elastase (PPE)] to greater than 360,000-fold in favor of HNE. The compound effectively inhibited HNE-hydrolysis of bovine ligamentum nuchae elastin. In pharmacokinetic studies, ICI 200,880 and ICI 200,355 displayed long retention times when administered directly to the lung and were rapidly eliminated after intravenous administration. Pretreatment of hamsters with either inhibitor before intratracheal administration of HNE produced dose- and time-dependent inhibition of enzyme-induced increases in lung weight, total lavageable red cells, and total lavageable white cells. Aerosol administration of ICI 200,880 produced similar results. Subcutaneous administration of either 50 or 100 mumol/kg (twice/day) of ICI 200,880 for 14 or 28 days prevented the time-dependent increase in alveolar diameter produced by a single intratracheal dose of PPE when compound dosing was initiated 24 h after the enzyme. Treatment of hamsters with the same protocol and doses of ICI 200,880 for 8 wk prevented the destructive lesion induced by a single intratracheal dose of HNE. It is concluded that ICI 200,880 and ICI 200,355 have biochemical, pharmacokinetic, and pharmacologic profiles that make them useful therapeutic agents for understanding the role of HNE in various diseases. ICI 200,880 is presently being evaluated in humans.