Short link N acts as a disease modifying osteoarthritis drug.

Osteoarthritis (OA) is a degenerative joint disease characterised by a progressive degradation of articular cartilage and underlaying bone and is associated with pain and disability. Currently, there is no medical treatment to reverse or even retard OA. Based on our previous reports, where we establish the repair potential of short Link N (sLN) in the intervertebral disc, a cartilage-like tissue, we hypothesise that sLN may hold similar promises in the repair of articular cartilage. This study aimed to determine if sLN, could prevent OA disease progression. Skeletally mature New Zealand white rabbits underwent unilateral anterior cruciate ligament transection (ACLT) of their left femorotibial joints to induce joint degeneration typical of OA. Beginning 3 weeks post-operatively, and every three weeks thereafter for 12 weeks, either saline (1 mL) or sLN (100 µg in 1 mL saline) was injected intraarticularly into the operated knee. Six additional rabbits underwent sham surgery but without ACLT or post-operative injections. The effects on gross joint morphology and cartilage histologic changes were evaluated. In the Saline group, prominent erosion of articular cartilage occurred in both femoral condyle compartments and the lateral compartment of the tibial plateau while, sLN treatment reduced the severity of the cartilage damage in these compartments of the knee showing erosion. Furthermore, statistically significant differences were detected between the joint OA score of the saline and sLN treated groups (p = 0.0118). Therefore, periodic intraarticular injection of sLN is a promising nonsurgical treatment for preventing or retarding OA progression, by reducing cartilage degradation.

Treatment durability, effectiveness, and safety with atazanavir/ritonavir-based HAART regimen in treatment-naïve HIV-infected patients.

PURPOSE: To describe the durability of treatment, virological and immunological response, and safety of an atazanavir/ritonavir (ATV/RTV)-based highly active antiretroviral therapy (HAART) regimen in treatment-naïve HIV-infected patients. METHODS: This was a multicentre retrospective study. Medical charts of antiretroviral-na'i've HIV-infected adults who initiated ATV/RTV (300/100 mg) from January 2004 to December 2007 in 10 Canadian clinics were reviewed. Data were collected from time of ATV/RTV treatment initiation until discontinuation of ATV. Durability of treatment and time to virological response were estimated with Kaplan-Meier functions. Change in viral load, CD4 cell counts, and lipid parameters were assessed with linear regression analyses. RESULTS: 176 patients were enrolled, 153 (86.9%) were male, and the majority (52.3%) were 40 to 54 years old. Duration of observation ranged from 1.6 to 56 months. The mean (SE) durability of treatment was 33.5 (0.7) months. There were 37 (21.0%) patients who discontinued ATV/ RTV, among whom 18 (10.2%) discontinued due to toxicity, suboptimal virological response, loss to follow-up, or death. The mean (SE) time to HIV viral load of <50 and <400 copies/mL was 6.6 (0.4) and 4.3 (0.3) months, respectively. At 96 weeks of treatment, least squares mean (LSM) estimated change in log10(HIV copies/mL) was -2.94 (P < .001) and +245 cells/mL (P < .001) for CD4 cell count. A significant LSM increase in HDL-C of 0.24 mmol/L (P = .007 for trend over time) was also observed; total cholesterol, triglycerides, and LDL-C increased over time but their change did not reach statistical significance. The most frequently reported adverse event was increased bilirubin (16.5%). CONCLUSIONS: ATV/RTV-based first-line HAART regimen demonstrated durability and effectiveness and was well tolerated in treatment-naïve HIV-infected patients.

Development and validation of the Spondyloarthritis Research Consortium of Canada (SPARCC) Enthesitis Index.

BACKGROUND: Enthesitis is a recommended core domain for assessment of ankylosing spondylitis (AS), but no measurement has yet been validated according to Outcome Measures in Rheumatoid Arthritis Clinical Trials (OMERACT) criteria. OBJECTIVE: The purpose of this study was to seek to validate an enthesitis index for patients with AS according to OMERACT criteria. METHODS: An enthesitis index was validated in two AS patient cohorts: (1) a longitudinal cohort (n = 223) and (2) 22 patients from three Canadian sites participating in a 24-week randomised placebo-controlled trial of adalimumab in AS. Construct validity was evaluated by correlation analysis with the Bath AS Disease Activity Index (BASDAI), the Bath AS Functional Index (BASFI) and quality of life instruments. Reproducibility was assessed by intraclass correlation coefficient (ICC), and responsiveness was assessed by Guyatt's effect size and standardised response mean. RESULTS: The most frequently affected sites were the greater trochanter and supraspinatus insertion ( approximately 20%). Patients with enthesitis had significantly greater scores for the BASDAI, BASFI, patient global, AS-specific quality of life index (ASQOL) and the Short Form 36 (SF-36) General Health Survey (p<0.001). The enthesitis score contributed significantly to variance in the BASDAI and BASFI. Interobserver ICCs were 0.96 in the longitudinal cohort and 0.89 and 0.77 in the adalimumab clinical trial cohort (for status and change score, respectively). Significant differences in change scores were evident for all patients after 24 weeks of adalimumab treatment, (p = 0.04), this being more significant when a subset of the most commonly affected entheses were analysed (p = 0.01). CONCLUSION: AS patients with enthesitis constitute a more severe subset of disease, and the Spondyloarthritis Research Consortium of Canada (SPARCC) Enthesitis Index is feasible and reliable for measurement of this condition. Discrimination requires further study in larger trials.

Impact of government health coverage for ART: The results of a 5-year experience in Quebec.

An analysis of national registry data for 5 years of in-vitro fertilization (IVF) funding in Quebec, Canada was compared with the previous complete year of non-funded IVF cycles, as well as the first complete year following the end of funding. The number of cycles, livebirth rates, age group of patients treated, use of donor gametes, multiple pregnancy rates and cycle cancellation rates were assessed. The total number of IVF cycles performed increased dramatically during the funded period, averaging over 10,000 cycles per year. There was no change in the age group distribution of patients treated, but less egg donation was performed. Interestingly, funding was also associated with an increase in the IVF cycle cancellation rate (17.0% versus 34.4%, P < 0.001), a dramatic decline in the multiple pregnancy rate (25.6% versus 4.9%, P < 0.001), and a decline in the livebirth rate per fresh embryo transfer in stimulated IVF cycles (32.3% versus 25.5%, P < 0.001). Although the livebirth rate for stimulated IVF declined, over 9000 babies were born as a result of the coverage. Lessons learned from this experience could help develop a more fiscally responsible programme that still facilitates access to IVF care.

Clinical Benefits of Tramiprosate in Alzheimer's Disease Are Associated with Higher Number of APOE4 Alleles: The "APOE4 Gene-Dose Effect".

BACKGROUND: Tramiprosate is an oral amyloid anti-aggregation agent that reduces amyloid oligomer toxicity in preclinical studies and was evaluated in two 78-week trials in North America and Western Europe that enrolled 2,025 patients with Mild to Moderate Alzheimer's Disease. The completed North American study did not achieve its efficacy objectives, but a pre-specified subgroup analysis suggested potential efficacy in apolipoprotein E4 (APOE4) carriers. To further explore this observation, we analyzed tramiprosate Phase 3 clinical data based on the number of APOE4 alleles. OBJECTIVES: To analyze tramiprosate efficacy, safety, and occurrence of vasogenic edema in the three APOE4 subgroups: homozygous, heterozygous and non-carriers. DESIGN: Randomized, double-blind, placebo-controlled parallel-arm multi-center studies. SETTING: Academic Alzheimer's disease and dementia centers, community-based dementia and memory clinics, and neuropsychiatric clinical research sites. PARTICIPANTS: Subjects included 2,025 patients, 50 years of age or older, with approximately 60% having APOE4 carrier status (10-15% homozygotes and 45-50% heterozygotes), and mild to moderate disease. All subjects were on stable symptomatic drugs. INTERVENTION: Randomized subjects received placebo, 100 mg BID, or 150 mg BID of tramiprosate. MEASUREMENTS: Co-primary outcomes in both studies were change from baseline in the ADAS-cog11 and CDR-SB assessment scales. RESULTS: Highest efficacy was observed in APOE4/4 homozygotes receiving 150 mg BID of tramiprosate, showing statistically significant effects on ADAS-cog and positive trends on CDR-SB (respectively, 40-66% and 25-45% benefit compared to placebo). APOE4 heterozygotes showed intermediate efficacy, and non-carriers showed no benefit. In 426 patients with MRI scans, no cases of treatment-emergent vasogenic edema were observed. In the three subgroups, the most common adverse events were nausea, vomiting, and decreased weight. CONCLUSIONS: The "APOE4 Gene-Dose effect" is likely explained by the high prevalence of amyloid pathology in symptomatic APOE4 carriers. In APOE4/4 Alzheimer's disease patients, the high dose of tramiprosate showed favorable safety and clinically meaningful efficacy in addition to standard of care.

Adult Still's disease: manifestations, disease course, and outcome in 62 patients.

Clinical and laboratory manifestations, disease course, outcome, and HLA associations were studied in an inception cohort of 62 subjects with adult Still's disease (ASD) from 5 Canadian universities. Twenty-eight patients (45%) were female and the median age at disease onset was 24 years. In general, the clinical features observed in our patients were identical to those in other published series. However, significantly higher frequencies of sore throat (92%), weight loss (76%), lymphadenopathy (74%), pleuritis (53%), pneumonitis (27%), and abdominal pain (48%) were noted in our patients compared to those in a recent literature review. Liver involvement with hepatomegaly (44%) or abnormal liver function tests (LFTs) (76%) was common and was responsible for the 2 deaths attributed to Still's disease in our series. Severe liver failure always occurred in conjunction with aspirin or NSAID therapy. Therefore, whether or not aspirin or other NSAIDs are used, we recommend close monitoring of LFTs in patients with ASD, especially early in the disease course. Laboratory manifestations were similar to those already reported. Leukocytosis (greater than or equal to 15,000/mm3) was present in 50 patients (81%), a normochromic, normocytic anemia (hemoglobin less than or equal to 10 g/dl) in 42 (68%), and an elevated ESR in all. The mean follow-up of the 62 patients was 70 months (range, 2-163). Twenty-one patients (34%) had a self-limited disease course, 15 (24%) an intermittent course, and 22 (36%) a chronic disease course. Four patients (6%) died, and 2 of these deaths were attributed to Still's disease. For those patients who experienced a recurrence of ASD, the flares were usually of shorter duration and milder in severity than the initial episode. No initiating factor for disease exacerbation was identified in our patients. Although 22 of 62 patients (36%) had a chronic disease course, 52 (90%) were in ARA Functional Class I, and only 4 and 2 patients were in ARA Functional Class II and III, respectively. Patients with Still's disease had higher scores than the controls on the Pain (P less than 0.01) and Physical Disability (P less than 0.05) subscales of Arthritis Impact Measurement Scales health status questionnaire. Joint radiographs performed at the follow-up evaluation disclosed typical carpometacarpal and intercarpal involvement in 16 of 39 patients. In our series, HLA-B17, B18, B35, and DR2 were significantly associated with ASD. Three significant predictors of an unfavorable outcome, either a chronic disease course or a longer time to clinical remission, were identified.(ABSTRACT TRUNCATED AT 400 WORDS)

A controlled study of the long-term prognosis of adult Still's disease.

PURPOSE: To assess the long-term prognosis of patients with adult Still's disease for physical and psychological disability, pain, social functioning, social support, medication use, formal education, occupation, time lost from work, and family income, and to contrast these results with those of same-sex sibling controls. PATIENTS AND METHODS: Patients were recruited from medical center-based cohorts in Pittsburgh and Eastern Canada and from a national survey of rheumatologists. Patients and same-sex sibling controls completed the Health Assessment Questionnaire for physical disability, the psychological and social function domains of the Arthritis Impact Measurement Scales, and the Interpersonal Skills Evaluation List questionnaire for social support, and replied to questions on medication use, formal education, occupation, time lost from work, and family income. RESULTS: One hundred four of 111 eligible adult Still's patients (94%) provided data. They identified 86 same-sex sibling controls, of whom 60 (70%) participated. The mean duration of adult Still's disease was 10 years. Approximately half of patients continued to require medication even 10 years after diagnosis. Patients had significantly higher levels of pain, physical disability, and psychological disability when compared with the controls. However, the levels of pain and physical disability were low compared to patients with other rheumatic diseases. Educational achievement, occupational prestige, social functioning and support, time lost from work, and family income were similar for both patients and controls. CONCLUSIONS: Despite causing disability, pain, and, in many, the need for long-term medication, patients with adult Still's disease are resilient. The disease did not interfere with educational attainment, occupational prestige, social functioning and support, time lost from work, or family income.

Measuring postoperative complications in general surgery patients using an outcomes-based strategy: comparison with complications presented at morbidity and mortality rounds.

BACKGROUND: This study was undertaken to compare the incidence of adverse postoperative outcomes recorded in a prospective general surgery database with that identified through weekly morbidity and mortality (M&M) rounds and to measure the impact of feedback of information to the providers of care. METHODS: Data were collected on patients admitted to one general surgery service between October 1, 1995, and May 15, 1996, and recorded in a computer database. Postoperative complications were graded in severity from I (minor) to IV (mortality). RESULTS: Of 479 admissions entered into the database during the study period, 325 (311 patients) led to operations and were further analyzed. Admissions resulting in complications were associated with longer hospital stays, regardless of complication grade, compared to uncomplicated admissions (p < 0.01). A total of 29 of 106 patients with postoperative complications were presented at M&Ms (27.4%). Whereas 15.4% of database patients with grade I complications were presented at M&Ms, this proportion increased to 22.2% for grade IIa, 34.8% for grade IIb, 33.3% for grade III, and 87.5% for grade IV. (p < 0.05 for grade I, IIa, and IIb compared to grade IV). A total of 58 of 142 patients in the first part of the study period developed complications (40.8%), compared to 53 of 183 patients in the second part of the study (29%, p = 0.034). CONCLUSIONS: Although most severe complications are recorded at M&M rounds, a large proportion of complications remain unreported. Monitoring of outcomes may contribute to improvements in quality of care.

Coronary artery bypass using internal mammary artery branches.

The excellent long-term patency rates achieved with use of the internal mammary artery (IMA) to bypass the left anterior descending coronary artery have stimulated a variety of approaches to expand the use of this conduit in coronary bypass surgery. In this report we document our results using the two terminal branches of the IMA to bypass two arteries in a Y configuration. Sixty-seven patients received IMA Y grafts during a 6-month period in 1987. A total of 150 IMA branch anastomoses were performed (8 patients received bilateral IMA Y grafts). Fourteen of 67 patients were revascularized using IMA grafts only. Operative mortality was 2 of 67 (3%), and follow-up mortality was 5 of 67 (7.5%). Fifty-eight patients could be evaluated 37 +/- 2.7 months later. Clinically 36% of patients reported some recurrence of angina and 12 of 47 (25%) had a positive electrocardiographic stress test. Four patients were reoperated on (2 redo coronary artery bypass grafting, 2 transplants). Sixty (40%) of the 150 branch anastomoses could be evaluated objectively and 30 (50%) were patent. Five (8.5%) were stenotic and 25 (41.5%) were occluded (overall patency rate, 58.5%). We conclude that although the use of IMA Y grafts is a technically feasible means to increase IMA usage, extended application of this technique cannot be recommended unless improved patency rates can be demonstrated.

Teaching cardiopulmonary resuscitation to CEGEP students in Quebec--a pilot project.

In order to increase CPR training in Quebec, we designed a pilot study to test out the efficacy of training CEGEP (junior college) students in CPR. We tried out four different methods of teaching CPR on students (Group A 'control', 4 h course, manikin to student ratio 1:4; Group B, 4 h course, manikin to student ratio 1:1; Group C, 2 h course, manikin to student ratio 1:1; Group D, video-assisted CPR instruction, manikin to student ratio 1:1). CPR skills were tested on a computerized manikin at the end of the initial course and again at the end of the semester in order to evaluate short and long-term retention of skills. There were no significant differences between the test groups and the control group in terms of compressions or ventilations at the beginning and end of the semester, however groups C and D performed significantly better primary surveys (Airway, Breathing, Circulation - ABC sequences) during the initial testing. The most common reasons reported by students for not taking CPR courses were the cost of courses (49.2%) and the inconvenience of courses (26.2%), similarly the two most common incentives which could get students to take CPR courses were; free courses (65.6%) and greater accessibility of courses (54.1%). Video-assisted CPR training appears to be feasible, enjoyable and as, if not more effective than traditional CPR courses. Instituting a mandatory video-assisted CPR program in the CEGEP system in Quebec and in high schools and colleges throughout the world, would be a cost-effective way to train massive amounts of young people in CPR.

Cardiopulmonary resuscitation: errors made by pre-hospital emergency medical personnel.

The purpose of the current study was to evaluate the CPR techniques of emergency healthcare professionals (emergency medical technicians, firemen, emergency first responders, CPR instructors). Skills were evaluated using a Laerdal Skillmeter Manikin, which provided a computerized printout of the quantifiable data during the CPR sequence. All of the 66 subjects in the study had completed a recertification course within the last 2 years (mean = 0.86 +/- 0.18, 95% CI). The sequence was videotaped for later viewing and for correlating the errors with the data. In addition, the participants were required to fill in a questionnaire. The most frequently occurring errors were observed in landmarking, overcompression, palpating a carotid pulse and insufficient ventilation. Although 98.5% of participants made an attempt to landmark their position for compression on the sternum, 35.9% of the total compressions performed by all subjects were incorrectly positioned on the patient's chest. Overcompression of the patient's chest accounted for 55.3% of incorrect compressions. Although 94% of participants attempted to verify a carotid pulse, only 45% were able to feel it and therefore stop performing cardiac massage. Of the total ventilations, 49% were below the American Heart Association (AHA) recommended minimum (800 ml). The results of this study showed a high rate of errors occurring in the CPR provided by emergency healthcare professionals.

Results of the surgical treatment of obesity.

A prospective, randomized trial comparing vertical banded gastroplasty (VBG) and vertical gastric bypass (GB) for obesity was completed in 106 patients who did not differ in baseline body mass index (BMI = kg/m2) or length of follow-up. The goal of this surgery was to return patients to within 50% of their ideal weight, i.e., a body mass index less than 35 kg/m2, and to accomplish this while maintaining a low risk for malnutrition as well as other morbidity and mortality. Success was defined as a BMI less than 35 kg/m2 because the mortality risk increases rapidly above this degree of obesity. Surgical failures were encountered in 43% of the 54 patients in the VBG group, all of whom had division between the vertical staple lines. The main causes of failure were stenosis and enlargement of the gastroplasty orifice. Surgery failed in 23% of the GB-treated patients, due to perforation of the vertical staple line. An isolated gastric bypass (IGB) not dependent on staples was performed as the remedial operation for the failures of both VBG and GB. IGB was significantly better than VBG or GB, with a success rate of 83% compared with 39% for VBG and 58% for GB. Subsequent experience since completion of this randomized trial in 54 consecutive patients supports IGB for primary, as well as remedial, operations for the morbidly obese (BMI = 40 to 50 kg/m2), as well as for patients who are super obese (BMI greater than 50 kg/m2).

International prospective evaluation of scintimammography with technetium-99m sestamibi: interim results.

OBJECTIVE: The purpose of this study is to evaluate the validity and reliability of scintimammography with technetium-99m (99mTc)-labeled sestamibi as an adjunct radiodiagnostic agent in the diagnosis of breast cancer. METHODS: This is a multicenter prospective cohort clinical trial that was initiated in June 1999 and will terminate May 2001. All patients with a physical or mammographic finding visiting any of the participating clinics are enrolled in the study. Patients who are younger than 18 years, pregnant, not willing to sign the consent form, or who have undergone an invasive procedure on the breast 30 days or less before scintimammography are excluded. At the time of the first interim report, 633 patients had been recruited from six Canadian centers. To date complete data have been collected for 530 patients. RESULTS: The mean (SD) age of the patients is 56 (12) years with a range between 24 and 85. There were 122 (23%) of the women in the sample who were postmenopausal and 36 (7%) who were perimenopausal. Breast density was graded as dense for 127 (24%), normal for 260 (50%), and fatty for 138 (26%). Of the 530 women in the study 156 (29%) had a palpable mass at physical examination. The mammographic results were classified as 76 (14%) breast imaging reporting and data system (BIRADS) 5, 60 (11%) BIRADS 4, 70 (13%) BIRADS 3 and the remaining BIRADS 2 or 1. The scintimammography results were positive for 118 (23%) of the patients and negative for 412 (78%). The histopathology showed malignant breast disease for 66 (12.5%) of the patients in the sample. Sensitivity and specificity of scintimammography for the detection of breast cancer was estimated 90.9% and 87.5%, respectively. A positive predictive value (PPV) of 50.8% with a negative predictive value of 98.5% and an accuracy of 87.5% were calculated. The PPV is interpreted as the posttest probability of disease given a positive test result. In this sample the pretest probability of disease would be best estimated by the prevalence of disease, which is equal to 12.5%. A positive scintimammography result would change the estimated probability to 51%, which is equivalent to a 400% change from the pretest value. Therefore a positive scintimammography result significantly increases our ability to predict the presence of malignant disease in this population. CONCLUSION: The interim results of the present study suggest that scintimammography with 99mTc-sestamibi is accurate and potentially useful as an adjunct to mammography for the detection of breast cancer.

Coronary artery bypass profile in Canada and the United States.

This study compares computer registry data on coronary bypass surgery from several centres in Canada and the United States to assess current trends in patient profile, and looks at demand and resources available for this form of treatment. A computerized registry established at the Royal Victoria Hospital in 1982 was used to document the profile of patients undergoing coronary artery bypass graft. Comparing 1988 to the previous six years (1982-87), a significant increase was found in patients with unstable angina (P less than 0.001) and abnormal left ventricular function (P less than 0.015) among those operated. The incidence of emergency operations also increased (P less than 0.001). The patient profile was similar to that of the Toronto university hospital population and many major United States university hospitals. The incidence of coronary artery bypass graft per 100,000 population, however, is much greater in the United States than in Canada (120 versus 56). Resources in many Canadian centres appear to be insufficient to meet demand for this type of surgical intervention.

Aortic flow velocity indices during upright exercise: reliability and relationship to cardiac output.

OBJECTIVE: To determine the intra- and interobserver reproducibility of Doppler-derived ascending aortic flow velocity measurements at rest and during upright exercise of increasing intensity; and to determine the relationship between Doppler-derived measurements and cardiac output obtained by the indirect Fick carbon dioxide rebreathing method in the same conditions. SUBJECTS: Twenty young healthy adults participated in the study; eight participated in the first part and 12 in the second. DESIGN: For the intra-observer study, subjects were submitted to three workloads (50, 100 and 150 W) of 5 mins duration on two occasions, seven days apart. The intra-observer reproducibility was determined by two technicians taking the Doppler measurements within 90 s during the steady state of each workload during the first session. The relationship between cardiac output and aortic flow velocities was studied by measuring cardiac output by carbon dioxide rebreathing and flow velocities by continuous wave Doppler ultrasound simultaneously at rest as well as during the last minute of the three workloads (50, 100 and 150 W) of 5 mins duration. RESULTS: The interobserver reproducibility was very good, with r values of 0.87 for peak velocity (PV) and 0.97 for peak acceleration (PA). The intra-observer reproducibility at the seventh day interval showed r values of 0.93 for PV and 0.96 for PA for one of the technicians. PV and PA of the ascending aortic flow correlated well with cardiac output (r = 0.85 and 0.82, respectively, P < 0.01). ANOVA showed that PV and PA increase proportionately with exercise intensity. CONCLUSION: PV and PA of ascending aortic flow are reproducible and reflect changes in left ventricular function during exercise.

Preventable death classification: interrater reliability and comparison with ISS-based survival probability estimates.

The purpose of the study was to compare the injury-related threat to survival estimated by the Injury Severity Score (ISS) and a committee of experts. The charts of 116 (73 fatalities and 43 survivors) patients with severe injuries were reviewed. A committee of nine clinicians classified each case as survivable, potentially survivable, and nonsurvivable based on anatomical descriptors, mechanism of injury, and patient's age. Majority was used to determine the final committee classification. Based on the ISS values, cases were classified as survivable (9-24), potentially survivable (25-49), and nonsurvivable (> 49). The results showed poor interrater reliability among the nine clinicians with an overall intraclass correlation coefficient of 0.43. The ISS-based classification had high agreement with the final committee classification (overall weighted kappa = 0.71). Lower agreement was observed for falls and with increasing number of injuries. This study has demonstrated no additional benefit for using a committee to classify injury severity on the basis of anatomical damage over applying ISS-based survival probabilities. The continued use of the ISS is supported.

Predictive validity and internal consistency of the pre-hospital index measured on-site by physicians.

Physiological measures of injury are used as triage tools to identify patients that require treatment in trauma centres. The Pre-Hospital Index (PHI) is based on systolic blood pressure, pulse, respiratory rate, (level of) consciousness, and presence of penetrating injury. The present study evaluated the validity and internal consistency of the PHI. The study was based on 628 patients assessed by physicians at the scene. Mean age was 38.7 years (SD = 24.8), and 65% were male. Motor vehicle collisions caused the injury for 45%. The majority had head/neck (56%) and extremity (45%) injuries. Mean PHI was 4.62 (SD = 5.77), 40% had a PHI of zero, 6% between 1 and 3, 32% between 4 and 7, and 21% greater than 7. The associations between PHI and rates of hospital admission, surgery, ICU treatment, mortality, duration of hospitalization, and length of ICU stay were significant (p < 0.001). A total of 260 (41.4%) patients had major trauma requiring treatment at a trauma centre. A PHI > 3 had 83% sensitivity and 67% specificity for identifying these patients. Internal consistency of the PHI variables was above the acceptable limits. This study has shown that the PHI is a valid and reliable physiological measure of injury severity and field triage tool.

Biodegradation of polyurethane foam, revisited, in the rat model.

In a prospective, randomized, controlled animal study, we systematically analyzed implanted polyurethane foam to determine the rate of degradation in the rat and to compare it to our previous human data. Sixteen 1-cm2 silicone-backed pieces of polyurethane foam were randomly implanted into dorsal subcutaneous pockets in each of 16 Sprague-Dawley rats. Eight animals had polyurethane implants removed at 3 and 6 months and the remaining 8 animals at 9 and 12 months. Specimens were examined either by histology or by scanning electron microscopy of recovered foam after collagenase digestion of the capsule. Histologically, there was evidence of foam degradation and a multinucleated giant cell inflammatory response surrounding the implants. With the scanning electron microscope, the strut width of the polyurethane foam upon implantation measured 51.4 +/- 1.3 microns (mean+SEM). This progressively decreased to 29.1 +/- 1.3 microns at 3 months, 16.6 +/- 0.6 micron at 6 months, 14.9 +/- 0.5 micron at 9 months, and 13.2 +/- 0.3 micron at 12 months (p < 0.0001). Duration of implantation has a significant impact on polyurethane degradation as measured by scanning electron microscopy in the rat animal model. The rate of degradation in the rat is much faster than in our human study, indicating that the rat studies cannot be used to draw conclusions regarding rate of biodegradation in humans.