New approaches for diagnosis of dry eye disease

We reviewed the literature for different diagnostic approaches for dry eye disease (DED) including the most recent advances, contradictions and promising diagnostic tools and technique. We performed a broad literature search for articles discussing different methods for diagnosis of DED including assessment of tear osmolarity, tear film stability, ocular biomarkers and others. Articles indexed in PubMed and google scholar were included. With the growing cosmetic industry, environmental pollution, and booming of digital screens, DED is becoming more prevalent. Its multifactorial etiology renders the diagnosis challenging and invites the emergence of new diagnostic tools and tests. Diagnostic tools can be classified, based on the parameter they measure, into tear film osmolarity, functional visual acuity, tear volume, tear turnover, tear film stability, tear film composition, ocular biomarkers and others. Although numerous methods exist, the most accurate diagnosis can be reached through combining the results of more than one test. Many reported tests have shown potential as diagnostic/screening tools, however, require more research to prove their diagnostic power, alone or in combination. Future research should focus on identifying and measuring parameters that are the most specific to DED diagnosis.     

A comprehensive non‐invasive framework for automated evaluation of acute renal transplant rejection using DCE‐MRI

The objective was to develop a novel and automated comprehensive framework for the non‐invasive identification and classification of kidney non‐rejection and acute rejection transplants using 2D dynamic contrast‐enhanced magnetic resonance imaging (DCE‐MRI). The proposed approach consists of four steps. First, kidney objects are segmented from the surrounding structures with a geometric deformable model. Second, a non‐rigid registration approach is employed to account for any local kidney deformation. In the third step, the cortex of the kidney is extracted in order to determine dynamic agent delivery, since it is the cortex that is primarily affected by the perfusion deficits that underlie the pathophysiology of acute rejection. Finally, we use an analytical function‐based model to fit the dynamic contrast agent kinetic curves in order to determine possible rejection candidates. Five features that map the data from the original data space to the feature space are chosen with a k‐nearest‐neighbor (KNN) classifier to distinguish between acute rejection and non‐rejection transplants. Our study includes 50 transplant patients divided into two groups: 27 patients with stable kidney function and the remainder with impaired kidney function. All of the patients underwent DCE‐MRI, while the patients in the impaired group also underwent ultrasound‐guided fine needle biopsy. We extracted the kidney objects and the renal cortex from DCE‐MRI for accurate medical evaluation with an accuracy of 0.97 ± 0.02 and 0.90 ± 0.03, respectively, using the Dice similarity metric. In a cohort of 50 participants, our framework classified all cases correctly (100%) as rejection or non‐rejection transplant candidates, which is comparable to the gold standard of biopsy but without the associated deleterious side‐effects. Both the 95% confidence interval (CI) statistic and the receiver operating characteristic (ROC) analysis document the ability to separate rejection and non‐rejection groups. The average plateau (AP) signal magnitude and the gamma‐variate model functional parameter α have the best individual discriminating characteristics. Copyright © 2013 John Wiley & Sons, Ltd.     

Skin infections in Egyptian renal transplant recipients

N.I. Bakr, E. El‐Sawy, A.F. Hamdy, M.A. Bakr. Skin infections in Egyptian renal transplant recipients.
Transpl Infect Dis 2011: 13: 131–135. All rights reserved Background. The risk of skin infections in renal transplant recipients (RTRs) has been described previously; however, it differs markedly by ethnic groups, skin type, and geographical location. We investigated the prevalence and nature of skin infections in a large series of RTRs in our locality in Egypt. Patients and methods. A total 302 RTRs (216 males and 86 females) were included in this study. They were screened for the presence of bacterial, fungal, and viral skin infections depending on clinical signs, Woods lamp examinations, culture, and biopsy if indicated. The patients were compared with 300 healthy controls matched for age and sex (200 males and 100 females) Results. We found 191 (63.25%) RTRs had some kind of skin infection. Folliculitis (10.3%), tinea versicolor (30.1%), dermatophytosis (19.5%), and onychomycosis (7.6%) were statistically significantly more common in RTRs compared with control subjects. Conclusion. Our RTRs have higher prevalence rates of folliculitis and superficial fungal infections than the healthy population and they should be searched for in every patient with renal transplantation to ensure early treatment and avoid complications. Low‐dose ketoconazole should be considered in renal transplant populations with high rates of superficial fungal infections, as it may reduce risk of such infections.