Pilot and Feasibility Studies of a Lifestyle Modification Program Based on the Health Belief Model to Prevent the Lifestyle-Related Diseases in Patients with Mental Illness.

In this study we have examined the feasibility of a program based on the health belief model (HBM), for its effectiveness in improving lifestyle-related diseases in patients with schizophrenia (SZ) and bipolar disorder (BD), which are often complicated with physical conditions. In this model, we attempted to enable patients to identify a "threat" and to find "balance between benefits and disadvantages". Subjects were carefully selected from among psychiatric patients by excluding any bias. Thus, the enrolled patients were 30 adult men and women with lifestyle-related diseases, or those with a body mass index (BMI) of over 24. Of these 30 subjects, 15 were randomly assigned to the intervention group and 10 the control group, since 5 subjects in the control voluntarily left from the study. Comparison of the intervention and control groups revealed significant improvement (p < 0.05) in HDL cholesterol in the intervention group. However, there were no significant changes in other variables. These findings support the usefulness and efficacy of HMB-based nutritional interventions for preventing lifestyle-related disorders among psychiatric patients. Further evaluation is needed with a larger sample size and a longer intervention period. This HMB-based intervention could be useful for the general population as well.

Oxygen distribution and vascular injury in the mouse eye measured by phosphorescence-lifetime imaging.

Maps of the oxygen distribution in the retina of the mouse eye were obtained by phosphorescence-lifetime imaging. Phosphor dissolved in the blood was excited by modulated light and phosphorescence imaged through microscope optics with an intensified-CCD camera. Phosphorescence lifetimes and oxygen pressures were calculated for each pixel of the images. The resolution was sufficient to permit the detection of anomalies that result in reduced oxygen pressures in individual retinal capillaries. High-resolution maps of oxygen distribution in the retina can provide greater understanding of the role of oxygen and vascular function in diseases of the eye.

Imaging oxygen pressure in the retina of the mouse eye.

The phosphorescence lifetime imaging system previously used to image oxygen in the retina of the cat eye was modified to allow imaging of phosphorescence lifetimes in the much smaller mouse eye. Following the lead of Shonat and coworkers, a frequency domain approach was used in which the excitation light source was modulated in a 50% on: 50% off square wave while the gate of the intensified CCD camera was similarly modulated but delayed with respect to the excitation. These were analyzed by fitting the intensity at each pixel to a sinusoid. The phase of the phosphorescence relative to the excitation was determined and from the phase shift and frequency, the phosphorescence lifetime was calculated. The Stern-Volmer relationship was then used to calculate the oxygen pressure at each pixel of the image array. High resolution maps of phosphorescence lifetime and oxygen pressure in the retina of the mouse eye have been attained. The retinal veins draining into the optic head appear as large, highly phosphorescent vessels against a lower phosphorescence background with a network of smaller vessels. The oxygen pressure in the retinal veins is typically from 20 to 30 mm Hg while the background has somewhat higher oxygen pressures. Experiments are underway to resolve the oxygen in the choroid from that in the retina. The arteries on the retinal surface can be observed, but their small diameter, relatively high oxygen pressures (> 90 mm Hg), and surrounding tissue with much lower oxygen pressures, makes accurate determination of the oxygen pressure a challenge.

Systemic rapamycin inhibits retinal and choroidal neovascularization in mice.

PURPOSE: Rapamycin exhibits significant antitumor/antiangiogenic activity that is coupled with a decrease in vascular endothelial growth factor (VEGF) production and a reduction in the response of vascular endothelial cells to stimulation by VEGF. VEGF plays a significant role in neovascular pathologies of the eye, thus we tested the possibility of using rapamycin to inhibit retinal and choroidal neovascularization (CNV). METHODS: CNV was induced in adult mice with laser photocoagulation. Retinal neovascularization was induced using the retinopathy of prematurity (ROP) hyperoxia/hypoxia model. Experimental animals received intraperitoneal (ip) injections of rapamycin (2 mg/kg/day or 4 mg/kg/day) for 1-2 weeks. Controls were not treated or received ip injections of phosphate buffered saline (PBS). Eyes were analyzed histologically for evidence of CNV or retinal neovascularization. ROP eyes were further analyzed for changes in VEGF and VEGF receptor (Flt-1 and Flk-1) protein content following rapamycin treatment. RESULTS: Rapamycin significantly reduced the extent of neovascularization in both the CNV and the ROP model. Immunohistochemical staining of treated and untreated ROP retina did not reveal a significant reduction in levels of VEGF protein or its receptors. Immunostaining for Flt-1 increased, while no obvious changes in Flk-1 were observed. Quantitative analysis of total protein via enzyme linked immunosorbent assay (ELISA) confirmed an increase in Flt-1 and VEGF, following drug treatment, with no effect on Flk-1. CONCLUSIONS: These results suggest rapamycin may provide an effective new treatment for ocular neovascularization.

Small interfering RNA (siRNA) targeting VEGF effectively inhibits ocular neovascularization in a mouse model.

PURPOSE: RNA interference mediated by small interfering RNAs (siRNAs) is a powerful technology allowing the silencing of mamalian genes with great specificity and potency. The purpose of this study was to demonstrate the feasibility of RNA interference mediated by siRNA in retinal cells in vitro and in the murine retina in vivo. METHODS: siRNAs specific for enhanced green fluorescent protein (EGFP) and murine and human vascular endothelial growth factor (VEGF) were designed. In vitro studies in human cell lines entailed modulation of endogenous VEGF levels through chemically induced hypoxia. Effects of siRNA treatment on these levels were measured by ELISA. In vivo studies evaluating effects of siRNA on levels of EGFP and VEGF were performed by co-injecting recombinant viruses carrying EGFP or hVEGF cDNAs along with the appropriate siRNAs subretinally in mice. Additional studies aimed at blocking production of endogenous mVEGF were performed using laser-induced choroidal neovascularization (CNV) in mice. Effects of in vivo treatments were evaluated ophthalmoscopically. Retinal/choroidal flat mounts were evaluated after perfusion with dextran-fluorescein. Alternatively, retinas were evaluated in histological sections or VEGF levels were measured in intact eyes using ELISA. RESULTS: Successful delivery of siRNA to the subretinal space was confirmed by observing significantly reduced levels of EGFP in eyes treated with Ad.CMV.EGFP plus EGFP-directed siRNA. siRNAs directed against hVEGF effectively and specifically inhibit hypoxia-induced VEGF levels in human cell lines and after adenoviral induced hVEGF transgene expression in vivo. In addition, subretinal delivery of siRNA directed against murine Vegf significantly inhibited CNV after laser photocoagulation. CONCLUSIONS: Delivery of siRNA can be used in vitro and in vivo to target specific RNAs and to reduce the levels of the specific protein product in the targeted cells. This work suggests that RNA interference has potential for application to studies of retinal biology and for the treatment of a variety of retinal diseases, including those involving abnormal blood vessel growth.

Inhibition of experimental choroidal neovascularization by irsogladine, an anti-gastric ulcer agent.

PURPOSE: To determine whether irsogladine inhibits experimental choroidal neovascularization (CNV) induced by laser photocoagulation in pigmented rats. METHODS: Focal laser photocoagulation (argon green 50 mW, 0.04 s, 200 microm) was applied to the retinochoroid of normal Brown Norway rats. Oral administration of irsogladine (5 mg/kg/day or 50 mg/kg/day) was started 1 week before and continued for 2 weeks after laser photocoagulation. Choroidal vascular casts were made 2 weeks after laser photocoagulation and were examined with a scanning electron microscope (SEM). CNV formation was classified according to three grades and evaluated. RESULTS: Laser-induced CNV formation was significantly reduced in rats given 5 mg/kg/day (p < 0.01) or 50 mg/kg/day of irsogladine (p < 0.001). Administration of 50 mg/kg/day of irsogladine was more effective in preventing CNV formation than 5 mg/kg/day (p < 0.001). The development of the vascular bud was especially inhibited by 50 mg/kg/day of irsogladine (p < 0.001). CNVs in rats treated with 50 mg/kg/day of irsogladine looked less well developed than those in controls. There was no significant side effect of irsogladine. CONCLUSIONS: Irsogladine inhibits the development of experimental CNV induced by photocoagulation in pigmented rats.

Natural course of experimental choroidal neovascularization: three-dimensional study with corrosion cast and scanning electron microscope.

OBJECTIVES: The details of the morphological features of choroidal neovascularization (CNV) remain unclear. The purpose of this study was to establish a CNV rat model and study the natural course of CNV using vascular casts and a scanning electron microscope (SEM). METHODS: Focal laser photocoagulation (argon green 50 mW, 0.04 s, 200 microm) was applied to Brown Norway pigmented rats. Choroidal vascular casts were prepared 1 and 3 days, 1 and 2 weeks, and 1, 3 and 6 months after laser photocoagulation. The choroidal casts were examined with a SEM. RESULTS: One day after photocoagulation, corrosion casts and SEM revealed complete defects of the choriocapillaris at the laser shot sites. One week after photocoagulation, small vascular buds originating from the damaged choriocapillaris were observed. Two weeks after photocoagulation, newly formed CNV originating from an individual laser burn was observed. One to three months after photocoagulation, these new vessels were connected to each other to form CNV networks. Six months later, some thin and atrophic vessels were observed in the CNV network. CONCLUSIONS: We succeeded in making fine corrosion casts of CNV formed by photocoagulation in pigmented rats and in demonstrating the details of CNV formation and regression. It is hoped that the results of this study will contribute to the development of a drug therapy for CNV and to the interpretation of diagnostic imaging of CNV in humans.