Enhancement of chronic cyclosporine nephrotoxicity by sodium depletion in an experimental mouse model

Summary: The major adverse reaction to cyclosporine A (CsA) is chronic nephrotoxicity. to elucidate the pathogenesis of CsA nephrotoxicity and the potential role of the renin-angiotensin system (RAS) in mediating this toxicity, a reliable mouse model would enable us to take advantage of various probes, and gene knockout animals available in this species, but not in the rat, would be extremely useful. Using the manoeuvre of sodium depletion and activation of RAS, an experimental model in the mouse has been developed to reproduce structural and functional characteristics of chronic CsA nephrotoxicity in humans. Mice were treated with CsA subcutaneously at dosages of 10 mg/kg per day and 30 mg/kg per day or olive oil as a placebo on a low sodium diet (LS) (0.01% sodium) for 28 days. Comparisons were made with mice treated with CsA at 100 mg/kg per day on a normal sodium diet (NS; 0.4% sodium) for 56 days. Cyclosporine A treatment induced significant increases in serum creatinine and blood urea nitrogen (BUN) and a decrease in creatinine clearance in mice on LS ( P <0.05 vs placebo). Sodium-depleted animals on CsA 30mg/kg per day treatment developed significant histological lesions in the kidneys consisting of tubulointerstitial fibrosis, arteriolopathy, nephrocalcinosis, and tubular injury after 28 days ( P <0.001 vs placebo). By contrast, CsA treatment in mice on NS did not induce functional and structural abnormalities in the kidneys even up to 56 days at a higher dose. This mouse model can be useful to gain further insights into the pathogenetic mechanisms of chronic CsA nephropathy.     

Femoral artery pseudoaneurysm: diagnosis with conventional duplex and color Doppler US

Three patients with clinically suspected pseudoaneurysm as a complication of femoral puncture were referred for ultrasound (US) evaluation with both conventional duplex Doppler US and color Doppler imaging. Pseudoaneurysm (n = 2) and simple hematoma (n = 2) were depicted with both Doppler systems, and a separate pseudoaneurysm and a hematoma were found in one patient. These diagnoses were confirmed surgically. Distinctive Doppler spectral waveforms and color Doppler findings enabled confident diagnoses. Color Doppler imaging allowed faster detection of intraaneurysmal flow, and the track between the injured artery and the pseudoaneurysm was identified only with color Doppler imaging. Duplex Doppler US with color Doppler imaging allows for the rapid, unequivocal diagnosis of pseudoaneurysm, thus enabling prompt treatment without the need for invasive diagnostic modalities.     

Renal Function and Blood Volume in Newborn Infant Related to Placental Transfusion

Inulin and PAH clearances, urine flow, filtration fraction, electrolyte excretion and blood volume studies were performed on 43 term vaginally delivered female normal infants during the first 12 hours of life and 26 during the 2nd to the 5th day of age. The umbilical cords of 22 infants were clamped within 5 seconds after birth and in 47 infants, the cords were clamped after their arterial pulsation had stopped. Compared with the late clamped infants, the blood volume, red cell volume and venous hematocrit were lower in the early clamped infants during the first five days of life. The urine flow, glomerular filtration rate (GFR), PAH clearance and effective renal blood flow were also lower in the early clamped infants during the first 12 hours of life, presumably due to the lower blood volume and blood pressures. At 2-5 days of age, the urine flow, GFR, PAH clearance and effective renal blood flow were the same in both groups of infants in spite of persistent difference in blood volume. The early clamped infants apparently achieved renal adaptation through means other than blood volume compensation. Data on electrolyte metabolism suggest that the late clamped infants filtered and reabsorbed larger amount of sodium than the early clamped infants during the first 6 hours of life, accompanied by a greater urine flow. These findings were appropriately achieved by the kidney in the process of body fluid regulation in response to the vascular distension and fluid transudation resulting from placental blood transfusion at birth.     

Thermal analysis of bulk filled composite resin polymerization using various light curing modes according to the curing depth and approximation to the cavity wall

Objective

The purpose of this study was to investigate the polymerization temperature of a bulk filled composite resin light-activated with various light curing modes using infrared thermography according to the curing depth and approximation to the cavity wall.

Material and Methods

Composite resin (AeliteFlo, Bisco, Schaumburg, IL, USA) was inserted into a Class II cavity prepared in the Teflon blocks and was cured with a LED light curing unit (Dr''s Light, GoodDoctors Co., Seoul, Korea) using various light curing modes for 20 s. Polymerization temperature was measured with an infrared thermographic camera (Thermovision 900 SW/TE, Agema Infra-red Systems AB, Danderyd, Sweden) for 40 s at measurement spots adjacent to the cavity wall and in the middle of the cavity from the surface to a 4 mm depth. Data were analyzed according to the light curing modes with one-way ANOVA, and according to curing depth and approximation to the cavity wall with two-way ANOVA.

Results

The peak polymerization temperature of the composite resin was not affected by the light curing modes. According to the curing depth, the peak polymerization temperature at the depth of 1 mm to 3 mm was significantly higher than that at the depth of 4 mm, and on the surface. The peak polymerization temperature of the spots in the middle of the cavity was higher than that measured in spots adjacent to the cavity wall.

Conclusion

In the photopolymerization of the composite resin, the temperature was higher in the middle of the cavity compared to the outer surface or at the internal walls of the prepared cavity.