The role of leukotriene inhibition using a 5-lipoxygenase (5-LO) inhibitor in a joint contracture model.

PURPOSE: Arthrofibrosis is a common inflammatory complication of joint trauma and surgery. 5lipoxygenase (5-LO) is a key enzyme involved in inflammation. Inhibition of 5-LO has been shown to reduce inflammation in heart and lung models but has not been examined in a joint contracture model. METHODS: Twenty-six rats underwent joint contracture. Six rats served as non-surgical controls. A 5-LO inhibitor, caffeic acid (CA), suspended in 10% ethanol was orally administered to 14 rats and ethanol without CA to the remaining 12 rats daily for 21 days. Leukotriene B4 (LTB4) levels were measured, both systemically and locally. 5-LO levels in the posterior capsule were quantified by measuring the ratio of the length of the posterior capsule demonstrating 5-LO immunostaining to the total length of the capsule. RESULTS: Joint contracture was successfully achieved in all rats who underwent manipulation. Levels of 5- LO measured in the posterior capsule were significantly increased in the animals who underwent surgery (56%/44-64) compared to the non-surgical control animals (7%/4-9). LTB4 levels were found to be significantly lower in the non-surgical control animals (107.79 ± 34.08 pg/ml) compared to all surgical animals (157.6 ± 55.3 pg/ml). CONCLUSION: Surgical intervention resulted in increased 5-LO activity of the synovial surface of the posterior capsule and increased LTB4 levels in the patellar tendon-fat pad. Oral administration of the 5LO inhibitor, CA, was ineffective at reducing systemic and local LTB4 levels and preventing knee joint contracture. Inhibiting 5-LO activity may still be effective in preventing arthrofibrosis and warrants further investigation.

Racial/ethnic disparities of the pact in predicting recidivism and court dispositions for justice-involved youth.

OBJECTIVE: Responding to the concern about racial/ethnic disparities (R/ED) in the use of risk assessment instruments (RAIs) in justice systems, previous research has overwhelmingly tested the extent to which RAI scores consistently predict recidivism across race and ethnicity (predictive bias). However, little is known about R/ED in the association between RAI measures and court dispositions (disparate application) for justice-involved youths. This study investigated predictive bias and disparate application of three risk measures-criminal history, social history, and the overall risk level-produced by the Positive Achievement Change Tool (PACT) for White, Black, and Hispanic justice-involved youths. HYPOTHESES: Given the mixed evidence in existing research for predictive bias and lack of evidence for disparate application, we did not make any specific hypothesis but conducted exploratory analyses. From a clinical perspective, however, we anticipated little or no evidence to support predictive bias and disparate application of the PACT among White, Black, and Hispanic youths in the jurisdiction we examined. METHOD: The sample consisted of 5,578 youths (11.4% White, 43.9% Black, and 44.7% Hispanic) who completed the PACT while in the Harris County Juvenile Probation Department, Texas. The outcome variables included recidivism (general and violent reoffending) and court dispositions (deferred adjudication, probation without placement, and probation with placement). We ran a series of moderating binary logistic regression models and moderating ordinal logistic regression models to evaluate predictive bias and disparate application. RESULTS: Race and ethnicity influenced how the criminal history score related to violent recidivism: This compromised the validity of the score as a predictor of recidivism. Moreover, evidence showed that the overall risk of reoffending was associated with harsher sanctioning decisions for Black and Hispanic youths than for White youths. CONCLUSION: Ensuring that RAI results are consistently interpreted and used in informing decisions is as important as ensuring that RAI scores function equally well in predicting recidivism regardless of race and ethnicity. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Exploring the possibility of early cataract diagnostics based on tryptophan fluorescence.

A novel route for early cataract diagnostics is investigated based on the excitation of tryptophan fluorescence (TF) at the red edge of its absorption band at 317 nm. This allows penetration through the cornea and aqueous humour to provide excitation of the ocular lens. The steepness of the red edge gives the potential of depth control of the lens excitation. Such wavelength selection targets the population of tryptophan residues, side chains of which are exposed to the polar aqueous environment. The TF emissions around 350 nm of a series of UV-irradiated as well as control lenses were observed. TF spectra of the UV cases were red-shifted and the intensity decreased with the radiation dose. In contrast, intensity of non-tryptophan emission with maximum at 435 nm exhibited an increase suggesting photochemical conversion of the tryptophan population to 435 nm emitting molecules. We demonstrate that the ratio of intensities at 435 nm to that around 350 nm can be used as a measure of early structural changes caused by UV irradiation in the lens by comparison with images from a conventional slit-lamp, which can only detect defects of optical wavelength size. Such diagnostics at a molecular level could aid research on cataract risk investigation and possible pharmacological research as well as assisting surgical lens replacement decisions.