Association Between Blood Pressure and Retinal Vessel Diameters Among Police Officers in the US Northeast.

OBJECTIVE: The aim of this study was to examine relationships of blood pressure with central retinal arteriolar equivalent (CRAE) and central retinal venular equivalent (CRVE) among 242 police officers. METHODS: Computerized retinal images of each eye were taken. Mean values of CRAE and CRVE were compared across hypertension status categories using analysis of variance and analysis of covariance. Associations of mean arterial blood pressure (MABP) with CRAE and CRVE were obtained using regression models. RESULTS: CRAE was significantly narrower in officers with uncontrolled hypertension (142.8 ±â€Š2.7 µm), compared with those with controlled hypertension (153.6 ±â€Š2.7 µm, P = 0.0013) and those with no hypertension (156.4 ±â€Š1.0 µm, P ≤ 0.0001) after covariate adjustment. CRAE decreased by 3.43 µm for each 5 mm Hg increase in MABP (P ≤ 0.0001). CONCLUSION: Uncontrolled hypertension was significantly associated with narrower retinal arterioles. No association was observed with retinal venules.

Shiftwork and the Retinal Vasculature Diameters Among Police Officers.

OBJECTIVE: To investigate associations of central retinal arteriolar equivalent (CRAE), a measure of retinal arteriolar width, and central retinal venular equivalents (CRVE), a measure of retinal venular width, with shiftwork in 199 police officers (72.9% men). METHODS: Shiftwork (day, afternoon, night) was assessed using electronic payroll records. Four digital retinal images per officer were taken. Mean diameters of the retinal vasculature were compared across shifts using analysis of variance (ANOVA)/analysis of covariance (ANCOVA). RESULTS: Among all officers (mean age = 46.6 ±â€Š6.8 years), shiftwork was not significantly associated with CRAE or CRVE. However, among current and former smokers, night-shift officers had a wider mean (±standard error [SE]) CRVE (230.0 ±â€Š4.5 µm) compared with day shift officers (215.1 ±â€Š3.5 µm); adjusted P = 0.014. CONCLUSIONS: Night shift schedule in current and former smokers is associated with wider retinal venules. Reasons for this association are not known. Longitudinal studies are warranted.

Directed differentiation of human embryonic stem cells toward chondrocytes.

We report a chemically defined, efficient, scalable and reproducible protocol for differentiation of human embryonic stem cells (hESCs) toward chondrocytes. HESCs are directed through intermediate developmental stages using substrates of known matrix proteins and chemically defined media supplemented with exogenous growth factors. Gene expression analysis suggests that the hESCs progress through primitive streak or mesendoderm to mesoderm, before differentiating into a chondrocytic culture comprising cell aggregates. At this final stage, 74% (HUES1 cells) and up to 95-97% (HUES7 and HUES8 cells) express the chondrogenic transcription factor SOX9. The cell aggregates also express cell surface CD44 and aggrecan and deposit a sulfated glycosaminoglycan and cartilage-specific collagen II matrix, but show very low or no expression of genes and proteins associated with nontarget cell types. Our protocol should facilitate studies of chondrocyte differentiation and of cell replacement therapies for cartilage repair.

Human meniscus cells express hypoxia inducible factor-1alpha and increased SOX9 in response to low oxygen tension in cell aggregate culture.

In previous work we demonstrated that the matrix-forming phenotype of cultured human cells from whole meniscus was enhanced by hypoxia (5% oxygen). Because the meniscus contains an inner region that is devoid of vasculature and an outer vascular region, here we investigate, by gene expression analysis, the separate responses of cells isolated from the inner and outer meniscus to lowered oxygen, and compared it with the response of articular chondrocytes. In aggregate culture of outer meniscus cells, hypoxia (5% oxygen) increased the expression of type II collagen and SOX9 (Sry-related HMG box-9), and decreased the expression of type I collagen. In contrast, with inner meniscus cells, there was no increase in SOX9, but type II collagen and type I collagen increased. The articular chondrocytes exhibited little response to 5% oxygen in aggregate culture, with no significant differences in the expression of these matrix genes and SOX9. In both aggregate cultures of outer and inner meniscus cells, but not in chondrocytes, there was increased expression of collagen prolyl 4-hydroxylase (P4H)alpha(I) in response to 5% oxygen, and this hypoxia-induced expression of P4H alpha(I) was blocked in monolayer cultures of meniscus cells by the hypoxia-inducible factor (HIF)-1alpha inhibitor (YC-1). In fresh tissue from the outer and inner meniscus, the levels of expression of the HIF-1alpha gene and downstream target genes (namely, those encoding P4H alpha(I) and HIF prolyl 4-hydroxylase) were significantly higher in the inner meniscus than in the outer meniscus. Thus, this study revealed that inner meniscus cells were less responsive to 5% oxygen tension than were outer meniscus cells, and they were both more sensitive than articular chondrocytes from a similar joint. These results suggest that the vasculature and greater oxygen tension in the outer meniscus may help to suppress cartilage-like matrix formation.

Chondrogenic differentiation of human bone marrow stem cells in transwell cultures: generation of scaffold-free cartilage.

Human bone marrow stem cells (hMSCs) have been shown to differentiate in vitro into a number of cell lineages and are a potential autologous cell source for the repair and replacement of damaged and diseased musculoskeletal tissues. hMSC differentiation into chondrocytes has been described in high-density cell pellets cultured with specific growth and differentiation factors. We now describe how culture of hMSCs as a shallow multicellular layer on a permeable membrane over 2-4 weeks resulted in a much more efficient formation of cartilaginous tissue than in established chondrogenic assays. In this format, the hMSCs differentiated in 14 days to produce translucent, flexible discs, 6 mm in diameter by 0.8-1 mm in thickness from 0.5 x 10(6) cells. The discs contained an extensive cartilage-like extracellular matrix (ECM), with more than 50% greater proteoglycan content per cell than control hMSCs differentiated in standard cell pellet cultures. The disc constructs were also enriched in the cartilage-specific collagen II, and this was more homogeneously distributed than in cell pellet cultures. The expression of cartilage matrix genes for collagen type II and aggrecan was enhanced in disc cultures, but improved matrix production was not accompanied by increased expression of the transcription factors SOX9, L-SOX5, and SOX6. The fast continuous growth of cartilage ECM in these cultures up to 4 weeks appeared to result from the geometry of the construct and the efficient delivery of nutrients to the cells. Scaffold-free growth of cartilage in this format will provide a valuable experimental system for both experimental and potential clinical studies.

Statin use and incident nuclear cataract.

CONTEXT: Statins are widely prescribed for their lipid-lowering effects but also have putative antioxidant properties. Oxidative stress is believed to play a role in the development of nuclear cataract, but little is known regarding the relationship of statin use and cataract incidence. OBJECTIVE: To evaluate the relationship of use of statins and incident cataract in adults in a midwestern community in the United States. DESIGN, SETTING, AND PARTICIPANTS: The Beaver Dam Eye Study, an observational, longitudinal, population-based study of age-related eye disease in Beaver Dam, Wis. There were 1299 persons who were seen at the third examination in 1998-2000, had gradable photographs in both eyes, and were deemed to be at risk of developing nuclear cataract within 5 years. MAIN OUTCOME MEASURE: Five-year incidence of cataract with respect to statin use. Cataracts were graded from photographs taken through the participant's dilated pupil. RESULTS: A total of 210 persons developed incident nuclear cataract in the interval from 1998-2000 to 2003-2005. Five-year incidence of nuclear cataract was 12.2% in statin users compared with 17.2% in nonusers (odds ratio [OR], 0.55; 95% confidence interval [CI], 0.36-0.84), controlling for age. When only never smokers without diabetes were assessed, the age-, lipid level-, and sex-adjusted OR was 0.40 (95% CI, 0.18-0.90). Five-year incidence of cortical cataract was 9.9% in statin users and 7.5% in nonusers (OR, 1.28; 95% CI, 0.79-2.08); posterior subcapsular cataract occurred in 3.0% of statin users and 3.4% of nonusers (OR, 0.82; 95% CI, 0.39-1.71). CONCLUSION: Statin use in a general population appears to be associated with lower risk of nuclear cataract, the most common type of age-related cataract.

The matrix-forming phenotype of cultured human meniscus cells is enhanced after culture with fibroblast growth factor 2 and is further stimulated by hypoxia.

Human meniscus cells have a predominantly fibrogenic pattern of gene expression, but like chondrocytes they proliferate in monolayer culture and lose the expression of type II collagen. We have investigated the potential of human meniscus cells, which were expanded with or without fibroblast growth factor 2 (FGF2), to produce matrix in three-dimensional cell aggregate cultures with a chondrogenic medium at low (5%) and normal (20%) oxygen tension. The presence of FGF2 during the expansion of meniscus cells enhanced the re-expression of type II collagen 200-fold in subsequent three-dimensional cell aggregate cultures. This was increased further (400-fold) by culture in 5% oxygen. Cell aggregates of FGF2-expanded meniscus cells accumulated more proteoglycan (total glycosaminoglycan) over 14 days and deposited a collagen II-rich matrix. The gene expression of matrix-associated proteoglycans (biglycan and fibromodulin) was also increased by FGF2 and hypoxia. Meniscus cells after expansion in monolayer can therefore respond to chondrogenic signals, and this is enhanced by FGF2 during expansion and low oxygen tension during aggregate cultures.