Corneal collagen cross‐linking for infectious keratitis: an update of clinical studies

Collagen cross‐linking (CXL) with ultraviolet light‐activated riboflavin is a corneal surface procedure developed for the treatment of keratoconus and corneal ectasia. With the known microbicidal and corneal stiffening effects of ultraviolet irradiation and photoactivated riboflavin, it has recently been introduced for the management of infectious keratitis, especially for ulcers resistant to antimicrobial therapy or associated with corneal melting. Various authors have attempted to use CXL as an adjunctive, salvage or even as the sole treatment for infectious corneal ulcers. The aim of this review was to provide a summary of the clinical studies in the literature. It is worth noting that there is still no consensus on the treatment protocol of CXL against infectious keratitis. The disparities in outcome measures, treatment protocol and study design can confound the interpretation and hamper the generalization of the study results. Based on current evidence, the role of CXL in infectious keratitis remained unclear despite the reported success in some clinical cases. Further investigations are warranted concerning the efficacy and safety of treating infectious keratitis with CXL.     

Enrollment in Hispanic Serving Institutions as a Moderator of the Relationship Between Drinking Norms and Quantity of Alcohol Use Among Hispanic College Students

Background: Hispanic college students represent a growing proportion of the college population. Studies have found that an individual's perception of the drinking of others is linked to one's own personal use and that college students frequently overestimate the drinking of their peers. The current study builds on previous college student drinking literature by examining the influence that attending a Hispanic-serving institution (HSI) has on the personal alcohol use and perception of peers’ drinking norms among Hispanic college students. Methods: This secondary data analysis utilized data from the American College Health Association's National College Health Assessment. Participants were self-identified Hispanics between the ages of 18 and 25 (N = 4336). Results: Results indicated that there was a significant interaction between attending an HSI and the perception of the number of drinks of a typical student. Specifically, the perception of others’ drinking was more strongly linked to personal drinking for students in non-Hispanic serving institutions. Conclusions: The protective effect of attending a Hispanic-serving institution may be related to a more culturally affirming college environment.     

Intensity discrimination deficits cause habituation changes in middle-aged Caenorhabditis elegans

The ability to learn and remember is critical for all animals to survive in the ever-changing environment. As we age, many of our biological faculties decay and of these, decline in learning and memory can be the most distressing. To carefully define age-dependent changes in learning during reproductive age in the nematode Caenorhabditis elegans, we performed a parametric behavioral study of habituation to nonlocalized mechanical stimuli (petri plate taps) over a range of intensities in middle-aged worms. We found that as worms age (from the onset of reproduction to the end of egg laying), response probability habituation increases (at both 10- and 60-second interstimulus intervals) and that these age-related changes were associated with a decrease in the discrimination between stimuli of different intensities. We also used optogenetics to investigate where these age-dependent changes occur. Our data suggest that the changes occur upstream of mechanosensory neuron depolarization. These data support the idea that declines in stimulus intensity discrimination abilities during aging may be one variable underlying age-related cognitive deficits.     

Heritability and linkage analysis of personality in bipolar disorder

Background

The many attempts that have been made to identify genes for bipolar disorder (BD) have met with limited success, which may reflect an inadequacy of diagnosis as an informative and biologically relevant phenotype for genetic studies. Here we have explored aspects of personality as quantitative phenotypes for bipolar disorder through the use of the Temperament and Character Inventory (TCI), which assesses personality in seven dimensions. Four temperament dimensions are assessed: novelty seeking (NS), harm avoidance (HA), reward dependence (RD), and persistence (PS). Three character dimensions are also included: self-directedness (SD), cooperativeness (CO), and self-transcendence (ST).

Methods

We compared personality scores between diagnostic groups and assessed heritability in a sample of 101 families collected for genetic studies of BD. A genome-wide SNP linkage analysis was then performed in the subset of 51 families for which genetic data was available.

Results

Significant group differences were observed between BD subjects, their first-degree relatives, and independent controls for all but RD and PS, and all but HA and RD were found to be significantly heritable in this sample. Linkage analysis of the heritable dimensions produced several suggestive linkage peaks for NS (chromosomes 7q21 and 10p15), PS (chromosomes 6q16, 12p13, and 19p13), and SD (chromosomes 4q35, 8q24, and 18q12).

Limitations

The relatively small size of our linkage sample likely limited our ability to reach genome-wide significance in this study.

Conclusions

While not genome-wide significant, these results suggest that aspects of personality may prove useful in the identification of genes underlying BD susceptibility.     

Interstitial high-dose-rate brachytherapy in the treatment of keloids: Moving toward a volumetric approach

PurposeBrachytherapy (BT) after surgical resection of keloids reduces the risk of local recurrence, but standardization of dose/technique is lacking. Typical keloid BT treatment utilizes a single-channel source prescribed to 5-mm depth. We investigated the dosimetry of a volume-based target definition for interstitial high-dose-rate BT treatment of keloids.Methods and MaterialsWe retrospectively identified consecutive 14 patients who had a total of 20 keloids treated with interstitial high-dose-rate BT for keloids at our institution between 2004 and 2014. Keloids were treated with a single 8 Gy fraction prescribed to 5 mm beneath the scar within 36 h of surgery. Retrospectively, a 3-mm skin high-risk clinical target volume (HR-CTV) was contoured under the scar for volume-based dose calculations.ResultsMean (SD) HR-CTV was 3.91 cm³ (3.1) and mean (SD) HR-CTV dose was 11.3 Gy (3.6). Mean D₉₀ (SD) was 62.9% (25.8) and mean V₁₀₀ (SD) was 56.5% (26.4). The mean V₁₅₀ (SD), V₂₀₀ (SD), and V₃₀₀ (SD) were as follows: 37.6% (19.9), 25.1% (14.4), and 11.3% (6.5), respectively. No local failures were reported at 9 months median followup. There were no Grade 2 or higher late toxicities.ConclusionsUsing a volume-based target definition, a wide range of target coverage was observed. This is likely a consequence of the curvature of the skin and the challenges of keeping the catheter equidistant from the skin across the target. Additional data are needed to define the potential clinical impact on outcomes/toxicities of dosimetric correlates with single-catheter BT keloid treatment.     

Neuroinflammatory phenotype in early Alzheimer's disease

Alzheimer's disease (AD) involves progressive neurodegeneration in the presence of misfolded proteins and poorly-understood inflammatory changes. However, research has shown that AD is genetically, clinically, and pathologically heterogeneous. In frozen brain samples of frontal cortex (diseased) and cerebellum (nondiseased) from the University of Kentucky Alzheimer's Disease Center autopsy cohort, we performed gene expression analysis for genes categorizing inflammatory states (termed M1 and M2) from early and late stage AD, and age-matched nondemented controls. We performed analysis of the serum samples for a profile of inflammatory proteins and examined the neuropathologic data on these samples. Striking heterogeneity was found in early AD. Specifically, early-stage AD brain samples indicated apparent polarization toward either the M1 or M2 brain inflammatory states when compared with age-matched nondisease control tissue. This polarization was observed in the frontal cortex and not in cerebellar tissue. We were able to detect differences in AD neuropathology, and changes in serum proteins that distinguished the individuals with apparent M1 versus M2 brain inflammatory polarization.     

Chemotherapy and peripheral neuropathy

Neurological Sciences - Chemotherapy-induced peripheral neurotoxicity (CIPN) is a major dose-limiting side effect of many anti-cancer agents, including taxanes, platinums, vinca alkaloids,...