Assessment of renal congestion in a rat model with congestive heart failure using superb microvascular imaging.

PURPOSE: Renal congestion is a therapeutic target in congestive heart failure. However, its detailed evaluation in a clinical setting is challenging. This study sought to assess renal congestion impairment using superb microvascular imaging (SMI), a simple and accessible method. METHODS: Dahl salt-sensitive rats, used as a model for congestive heart failure, underwent central venous pressure (CVP) measurements. Renal congestion was evaluated through measurements of renal medullary pressure (RMP) and assessment of renal perfusion using contrast-enhanced ultrasonography at both the early (control group) and heart failure phases (HF group). All rats were assessed with SMI. The region of interest (ROI) was set in interlobular vessels, interlobar vessels, and a combination of these areas. The area ratio was calculated from the color pixel count in the ROI divided by the total pixel count in the ROI. Intrarenal perfusion index (IRPI) was defined as (maximum area ratio-minimum area ratio) / maximum area ratio. RESULTS: There were no significant differences in renal function and left ventricular ejection fraction between the two groups. CVP, time-to-peak (TTP) in the medulla, and RMP were higher in the HF group than in the control group. In the HF group, IRPI, evaluated in the interlobular vessels, was significantly higher than in the control group. IRPI was positively correlated with TTP in the medulla (p = 0.028, R = 0.60) and RMP (p < 0.001, R = 0.84), indicating that IRPI reflected renal congestion. CONCLUSIONS: IRPI is a useful tool for assessing renal congestion in rats with congestive heart failure.

Ultrastructural changes in the choriocapillaris of N-methyl-N-nitrosourea-induced retinal degeneration in C57BL/6 mice.

N-methyl-N-nitrosourea (MNU) is known to cause apoptosis of photoreceptor cells and changes in retinal pigment epithelium (RPE). However, the changes in choriocapillaris, which nourishes photoreceptor cells by diffusing tissue fluid through RPE, have not been reported in detail. Therefore, we studied the ultrastructural transformation in and around the choriocapillaris to characterize the interdependence between choriocapillaris and surrounding tissue components in a mouse model. Seven-week-old male C57BL/6 mice were given a single intraperitoneal injection of MNU (60 mg/kg of body weight). Perfusion-fixed eyeballs were examined chronologically using immunohistochemistry and electron microscopy until the photoreceptor cells were lost. Sequential ultrastructural changes were observed in photoreceptor cells, RPE, Bruch's membrane, choriocapillaris, and choroidal melanocytes after an MNU injection. The lumens of the choriocapillaris narrowed following dilation, and the vascular endothelium showed structural alterations. When the photoreceptor cells were completely lost, the choriocapillaris appeared to be in a recovery process. Our results suggest that transport abnormality through Bruch's membrane and structural changes in the choroid might have influenced the morphology of choriocapillaris. The thin wall of the choriocapillaris appears to be the cause of the vulnerability with its altered morphology.

Frequency and clinical features of intraocular inflammation in Tokyo.

BACKGROUND: To investigate frequencies and clinical features of intraocular inflammation (uveitis) in Tokyo, Japan. METHODS: Records of 834 consecutive new referral patients (352 men, 482 women) examined at the Kyorin University Hospital from April 2000 to December 2007 were retrospectively reviewed. RESULTS: Mean age at onset was 44.8 years for men and 47.0 years for women. By anatomical classification, 229 patients (27.4%) had anterior uveitis, 10 (1.2%) had intermediate uveitis, 183 (21.9%) had posterior uveitis and 412 (49.4%) had panuveitis. The most common diagnoses were Vogt-Koyanagi-Harada (VKH) disease (11.0%), sarcoidosis (6.9%), acute anterior uveitis (6.5%), Behçet's disease (5.8%) and tuberculosis (4.3%). In the third and fourth decades, the most common diseases were Behçet's disease for men and VKH for women, whereas over 60 years of age, the most common diseases were VKH for men and sarcoidosis for women. Systemic corticosteroids were used in 25.5% of patients, and other immunomodulatory agents were required in 8.7% of patients. CONCLUSIONS: The most frequent diagnoses were sarcoidosis, VKH disease, acute anterior uveitis, Behçet's disease and tuberculosis, with Behçet's disease being common in young men and sarcoidosis being common in elderly women. One-fourth of patients received systemic corticosteroids and 8.7% of patients required other immunomodulatory agents.