Joint capsule matrix turnover in a rabbit model of chronic joint contractures: Correlation with human contractures.

To evaluate changes in matrix molecules of the joint capsule, the right knees of 24 skeletally mature female NZW rabbits were immobilized while the contralateral limb served as an unoperated control. The immobilization was discontinued at 8 weeks and the rabbits were divided among four groups (n = 6) based on the number of weeks the right knees were remobilized: 0, 8, 16, or 32. Three rabbits (six knees) that did not have operations provided normal control joint capsules. The mRNA levels for collagen types I, II, and III, and MMP-1 and -13 were significantly increased in the joint capsules of the contracture knees in all groups when compared to normal and contralateral limb joint capsules. In contrast, the mRNA levels for TIMP-1, -2, and -3 were decreased in the joint capsules of the contracture knees in all groups when compared to normal and contralateral limb joint capsules. The mRNA levels for lumican and decorin were increased in the joint capsules of the contracture knees in all groups when compared to normal capsules. Many of the changes observed in this animal model are similar to those observed in human joint capsules from posttraumatic elbow contractures, supporting the value of this rabbit model.     

The relationship between interviewers' characteristics and ratings assigned during a multiple mini-interview.

PURPOSE: To assess the consistency of ratings assigned by health sciences faculty members relative to community members during an innovative admissions protocol called the Multiple Mini-Interview (MMI). METHOD: A nine-station MMI was created and 54 candidates to an undergraduate MD program participated in the exercise in Spring 2003. Three stations were staffed with a pair of faculty members, three with a pair of community members, and three with one member of each group. Raters completed a four-item evaluation form. All participants completed post-MMI questionnaires. Generalizability Theory was used to examine the consistency of the ratings provided within each of these three subgroups. RESULTS: The overall test reliability was found to be .78 and a Decision Study suggested that admissions committees should distribute their resources by increasing the number of interviews to which candidates are exposed rather than increasing the number of interviewers within each interview. Divergence of ratings was greater within the pairing of community member to faculty member and least for pairings of community members. Participants responded positively to the MMI. CONCLUSION: The MMI provides a reliable protocol for assessing the personal qualities of candidates by accounting for context specificity with a multiple sampling approach. Increasing the heterogeneity of interviewers may increase the heterogeneity of the accepted group of candidates. Further work will determine the extent to which different groups of raters provide equally valid (albeit different) judgments.     

In vitro characterization of peptide-modified p(AAm-co-EG/AAc) IPN-coated titanium implants.

Interpenetrating polymer networks (IPNs) of poly(acrylamide-co-ethylene glycol/acrylic acid) [p(AAm-co-EG/AAc)] functionalized with an -Arg-Gly-Asp- containing peptide derived from rat bone sialoprotein [bsp-RGD(15)] were grafted to titanium implants in an effort to modulate osteoblast behavior in vitro. Surface characterization data were consistent with the presence of an IPN, and ligand density measurements established that the range of peptide density on the modified implants spanned three orders of magnitude (0.01-20 pmol/cm2). In vitro biological characterization of the modified implants employing the primary rat calvarial osteoblast (RCO) model resulted in the identification of a critical ligand density (0.01相似文献   

Cataract surgery takes longer in functionally monocular patients.

BACKGROUND AND OBJECTIVES: To determine differences in the amount of work involved in caring for functionally monocular patients who undergo cataract surgery compared with binocularly sighted patients. PATIENTS AND METHODS: This was a retrospective study that included 100 consecutive functionally monocular patients and 100 binocularly sighted control patients matched by age (+/-5 years) and date of surgery ( +/-1 year). Office records were reviewed to determine several measures of office and operating room work effort. RESULTS: There was no difference between groups in preoperative telephone calls (P = .136), postoperative telephone calls (P = .580), preoperative office visits (P = .875), postoperative office visits (P = .601), or the number of times surgery was scheduled (P = 1.00). Monocular patients required more time for surgery (37.4 minutes) than binocular patients (32.4 minutes) (P= .010). CONCLUSIONS: It takes longer to perform cataract surgery on functionally monocular patients than on binocularly sighted patients.     

Provider attitudes regarding use of an immunization information system to identify children with asthma for influenza vaccination.

OBJECTIVES: Despite longstanding national guidelines, many children with asthma do not receive annual influenza vaccinations. Information from Medicaid-administrative claims data was integrated into the Michigan Care Improvement Registry (MCIR) to prompt providers regarding influenza vaccination among children with high-risk conditions such as asthma. The attitudes of pediatric primary care providers regarding the implementation of this system were assessed. METHODS: A survey was sent in February 2006 to office-based general pediatricians (n = 300) and family physicians (n = 300) in Michigan. The survey focused on influenza vaccination during the 2005-2006 influenza season and attitudes regarding a reminder system for providers using the MCIR. RESULTS: Overall response rate was 67 percent. MCIR participation was high (91%) among respondents, and most (83%) had MCIR information available to them prior to visits with pediatric patients. Most physicians (75%) considered the MCIR high-risk indicator for influenza vaccination a feature that they would find helpful. Some respondents reported concerns that the reminder system is limited to Medicaid patients only (44%) and regarding the completeness of Medicaid data to identify children with asthma (24%). CONCLUSIONS: Physicians have a positive overall view of a statewide registry-based automated reminder system to assist in identifying children with asthma for influenza vaccination, albeit with specific areas of concern.     

Risk indicators for third molar caries and periodontal disease in senior adults.

PURPOSE: This study was designed to identify risk indicators for the prevalence at enrollment and incidence over 36 months of periodontal pathology and coronal caries experience affecting third molars in a community-based study of people over 65 years of age. SUBJECTS AND METHODS: Data from a subsample of 810 dentate subjects from the Piedmont 65+ Study were available for analyses. All visible teeth were examined. Periodontal probing measures were taken at 2 sites, mesiobuccal and buccal/facial. Clinical data on caries experience were collected by visual-tactile examination. At enrollment, 340 subjects had at least 1 visible third molar; all were examined for caries experience. Periodontal probing measures were available for 277 of these same subjects. The significance of the possible risk indicators for periodontal pathology and caries affecting third molars was determined by chi(2) tests. Statistical significance was set at .05. Logistic multivariable models were used to derive odds ratios and 95% confidence intervals. RESULTS: African-American subjects were more likely to have visible third molars (P < .01). Caucasian subjects were more likely to have third molar coronal caries experience (P < .01), as were subjects with greater than a high school education and those with a dental visit within 3 years (both P < .01). However, African American subjects were more likely to have periodontal pathology, CALs >/= 3 mm on third molars (P < .01), as were those who used tobacco (P < .01). None of the other risk indicators we studied were associated with progression of periodontal pathology or coronal caries experience on visible third molars. CONCLUSION: In this population study of senior adults, Caucasians and African Americans appear to have different levels of risk for caries experience and periodontal pathology affecting retained third molars.     

Release of Proinflammatory Cytokines During Pediatric Cardiopulmonary Bypass: Heparin-Bonded Versus Nonbonded Oxygenators

Background. Heparin bonding of the cardiopulmonary bypass (CPB) circuit may be associated with a reduced inflammatory response and improved clinical outcome. The relative contribution of a heparin-bonded oxygenator (ie, >80% of circuit surface area) to these effects was assessed in a group of pediatric patients.

Methods. Twenty-one pediatric patients undergoing CPB operations were assigned randomly to receive either a heparin-bonded oxygenator (group H, n = 11) or a nonbonded oxygenator (group C, n = 10) in otherwise nonbonded circuits. The two groups were similar in pathology, age, weight, CPB time, and cross-clamp time. Plasma levels of the cytokines tumor necrosis factor-, interleukin-6, and interleukin-8, as well as terminal complement complex, neutrophils, and elastase, were analyzed before, during, and after CPB.

Results. Significant levels of tumor necrosis factor- were not detected in either group. Plasma levels of all other markers increased during and after CPB compared with baseline. Plasma levels of interleukin-6 peaked in both groups 2 hours after the administration of protamine but remained significantly higher in group C 24 hours after operation. Plasma concentrations of interleukin-8 peaked at similar levels in both groups 30 minutes after protamine administration and returned to baseline thereafter. Levels of terminal complement complex and elastase peaked in both groups 30 minutes after protamine administration. Plasma levels of terminal complement complex were significantly higher at the end of CPB and after protamine administration in group C. Elastase levels were significantly higher 2 and 24 hours after CPB in group C. The ventilation time of patients in group H was significantly lower than that of patients in group C: 10 (range, 3 to 24) versus 22 (range, 7 to 24) hours, respectively (p < 0.01).

Conclusions. The present study confirms the proinflammatory nature of pediatric operations and demonstrates a lessened systemic inflammatory response with the use of heparin-bonded oxygenators. This is achieved without bonding of the entire circuit, which could have significant cost-benefit implications by negating the need for custom-built heparin-bonded circuitry.     

Effect of compressive follower preload on the flexion-extension response of the human lumbar spine.

Traditional experimental methods are unable to study the kinematics of whole lumbar spine specimens under physiologic compressive preloads because the spine without active musculature buckles under just 120 N of vertical load. However, the lumbar spine can support a compressive load of physiologic magnitude (up to 1200 N) without collapsing if the load is applied along a follower load path. This study tested the hypothesis that the load-displacement response of the lumbar spine in flexion-extension is affected by the magnitude of the follower preload and the follower preload path. Twenty-one fresh human cadaveric lumbar spines were tested in flexion-extension under increasing compressive follower preload applied along two distinctly different optimized preload paths. The first (neutral) preload path was considered optimum if the specimen underwent the least angular change in its lordosis when the full range of preload (0-1200 N) was applied in its neutral posture. The second (flexed) preload path was optimized for an intermediate specimen posture between neutral and full flexion. A twofold increase in flexion stiffness occurred around the neutral posture as the preload was increased from 0 to 1200 N. The preload magnitude (400 N and larger) significantly affected the range of motion (ROM), with a 25% decrease at 1200 N preload applied along the neutral path. When the preload was applied along a path optimized for an intermediate forward-flexed posture, only a 15% decrease in ROM occurred at 1200 N. The results demonstrate that whole lumbar spine specimens can be subjected to compressive follower preloads of in vivo magnitudes while allowing physiologic mobility under flexion-extension moments. The optimized follower preload provides a method to simulate the resultant vector of the muscles that allow the spine to support physiologic compressive loads induced during flexion-extension activities.