Crimp around the globe; patterns of collagen crimp across the corneoscleral shell.

Our goal was to systematically quantify the collagen crimp morphology around the corneoscleral shell, and test the hypothesis that collagen crimp is not uniform over the globe. Axial longitudinal cryosections (30 µm) of three sheep eyes, fixed at 0 mmHg IOP, were imaged using polarized light microscopy to quantify the local collagen in 8 regions: two corneal (central and peripheral) and six scleral (limbus, anterior-equatorial, equatorial, posterior-equatorial, posterior and peripapillary). Collagen crimp period (length of one wave), tortuosity (path length divided by end-to-end length), waviness (SD of orientation), amplitude (half the peak to trough distance), and conformity (width of contiguous similarly oriented bundles) were measured in each region. Measurements were obtained on 8216 collagen fiber bundles. When pooling measurements across the whole eye globe, the median crimp values were: 23.9 µm period, 13.2 µm conformity, 0.63 µm amplitude, 1.006 tortuosity, and 12.7° waviness. However, all parameters varied significantly across the globe. Median bundle periods in the central cornea, limbus, and peripapillary sclera (PPS) were 14.1 µm, 29.5 µm, and 22.9 µm, respectively. Median conformities were 20.8 µm, 14.5 µm, and 15.1 µm, respectively. Median tortuosities were 1.005, 1.007, and 1.007, respectively. Median waviness' were 11.4°, 13.2°, and 13.2°, respectively. Median amplitudes were 0.35 µm, 0.87 µm, and 0.65 µm, respectively. All parameters varied significantly across the globe. All regions differed significantly from one another on at least one parameter. Regions with small periods had large conformities, and bundles with high tortuosity had high waviness and amplitude. Waviness, tortuosity, and amplitude, associated with nonlinear biomechanical behavior, exhibited "double hump" distributions, whereas period and conformity, representing tissue organization, were substantially different between sclera and cornea. Though the biomechanical implications and origin of the patterns observed remain unclear, our findings of well-defined patterns of collagen crimp across the corneoscleral shell, consistent between eyes, support the existence of mechanisms that regulate collagen characteristics at the regional or smaller levels. These results are experimental data necessary for more realistic models of ocular biomechanics and remodeling.

RNA-binding protein HuR regulates RGS4 mRNA stability in rabbit colonic smooth muscle cells.

Regulator of G protein signaling 4 (RGS4) regulates the strength and duration of G protein signaling and plays an important role in smooth muscle contraction, cardiac development, and psychiatric disorders. Little is known about the posttranscriptional regulation of RGS4 expression. We cloned the full-length cDNA of rabbit RGS4, which contains a long 3'-untranslated region (UTR) with several AU-rich elements (AREs). We determined whether RGS4 mRNA stability is mediated by the RNA-binding protein human antigen R (HuR) and contributes to IL-1ß-induced upregulation of RGS4 expression. We show that IL-1ß treatment in colonic smooth muscle cells doubled the half-life of RGS4 mRNA. Addition of RGS4 3'-UTR to the downstream of Renilla luciferase reporter induced dramatic reduction in the enzyme activity and mRNA expression of luciferase, which was attenuated by the site-directed mutation of the two 3'-most ARE sites. IL-1ß increased luciferase mRNA stability in a UTR-dependent manner. Knockdown of HuR significantly aggravated UTR-mediated instability of luciferase and inhibited IL-1ß-induced upregulation of RGS4 mRNA. In addition, IL-1ß increased cytosolic translocation and RGS4 mRNA binding of HuR. These findings suggest that 3'-most ARE sites within RGS4 3'-UTR are essential for the instability of RGS4 mRNA and IL-1ß promotes the stability of RGS4 mRNA through HuR.

Health behavior practice among understudied Chinese and Filipino Americans with cardiometabolic diseases.

Lifestyle modification and health behavior practice among the individuals with cardiometabolic diseases (CMD) are important for secondary prevention and disease control. This study was designed to investigate and compare health behavior practices among Chinese and Filipino Americans with CMD. Three hundred seventy-four Asian Americans (211 Chinese and 163 Filipino) who reside in the greater Philadelphia region and had either CMD or no identified disease were included in the study. Information on smoking, alcohol intake, physical activity, and salt and sweets consumption was collected, as well as demographic and acculturative characteristics. Of the 374 participants, 241 (64.4%) had CMD and 133 (35.6%) had no identified disease. The majority of Chinese and Filipino Americans with CMD failed to meet the dietary and physical activity guidelines, and only a small percentage of them restricted their amount of salt added to food and amount of sweets consumption. Compared to participants with no disease, Chinese participants with CMD were more likely to "never" add salt to food (AOR 4.42 compared to "frequently"). Filipino Americans with CMD were less likely to be those who "never" consume sweets than those who frequently consume sweets (AOR = 0.12). Among the participants with CMD, Chinese participants with CMD were less likely to restrict drinking (AOR 0.11) than Filipinos with CMD. The findings suggest that tailored interventions for Chinese and Filipino Americans with CMD should be developed to enhance their compliance to behavioral guidelines to prevent further disease progression and complications.

Formalin Fixation and Cryosectioning Cause Only Minimal Changes in Shape or Size of Ocular Tissues.

Advances in imaging have made it increasingly common to study soft tissues without first embedding them in plastic or paraffin and without using labels or stains. The process, however, usually still involves fixation and cryosectioning, which could deform the tissues. Our goal was to quantify the morphological changes of ocular tissues caused by formalin fixation and cryosectioning. From each of 6 porcine eyes, 4 regions were obtained: cornea, equatorial and posterior sclera, and posterior pole containing the optic nerve head. Samples were imaged using visible light microscopy fresh, 1-minute and 24-hours post-fixation, and post-cryosectioning. Effects were assessed by 14 parameters representing sample size and shape. Overall, formalin fixation and sectioning caused only minimal changes to the ocular tissues, with average percentage parameter differences of 0.1%, 1%, and 1.2% between fresh and post-fixing by 1 minute, 24 hours, and post-cryosectioning, respectively. Parameter changes were not directional, and were only weakly dependent on the duration of fixation and the region of the eye. These results demonstrate that formalin fixation and cryosectioning are good choices for studying ocular tissue morphology and structure, as they do not cause the large tissue shrinkage or distortions typically associated with other, more complicated, techniques.