Index for predicting post-operative residual liver function by pre-operative dynamic liver SPET

To predict residual liver function before hepatic resection, we devised a predictive index by combining clearance values with functional liver volume measured by liver dynamic single photon emission tomography (SPET). Forty-seven patients with liver disease underwent liver dynamic SPET with 99Tcm-Sn colloid before hepatic resection. There were no operation-related deaths. Three patients died from hepatic failure more than 1 month following the operation. Their predictive indices were 0.24, 0.33 and 0.34. When the predictive index was above 0.35, no patient had symptoms of hepatic failure or died. Our data suggest that when the predictive index is above 0.35, there is a low probability of hepatic failure after hepatectomy.     

Blood platelets in severely injured burned patients

Unbelievable decrease of blood-platelet in the severely burned patients during the treatment of skingrafting caused two patients to unexpected death. From the records of changes of platelet number, a certain 'platelet curve' was made. By observing the curve, our treatments of skingrafting were carried out during the stable period and from then on we had no death cases.     

Development of the computerized dental cast form analyzing system--three dimensional diagnosis of dental arch form and the investigation of measuring condition

To analyze the functional and morphological harmonies of the tooth and dental arch, a computerized system to measure a dental cast and to detect the apex of dental cusps and angle points of incisors was developed. Detailed morphology in the measured dental cast could be displayed distinctively by computer graphics (CG) with a surface model. Accuracy in determining the position of the apex of the dental cusp was examined by increasing the measuring pitch from 50 microns to 400 microns, the error increased gradually with increased measuring pitch. Taking the measuring error, the time for measurement and the memory size for analysis into account, a measuring pitch of 200 microns was determined to be reasonable. Three-dimensional data measurements from the apex of the dental cusp in molar, and the mesial and distal angles in canine and incisor were fitted to a polynomial formula. In the present measured model, the 4th order polynomial formula was used for the dental arch, and the 2nd order polynomial formula was used for the anteroposterior and lateral occlusal curves. These formulae could be simultaneously superimposed on the surface model of the dental cast, and displayed using CG.     

Aberrant gastric venous drainage into the medial segment: demonstration by color Doppler sonography

BACKGROUND: Aberrant gastric venous drainage (AGVD) into the posterior edge of the medial segment of the liver (segment IV) is the main cause of pseudolesion on computed tomography (CT) during arterial portography. We estimated the prevalence of AGVD into the medial segment of the liver with color and power Doppler ultrasound (US). METHODS: Screening gray-scale and color Doppler and power Doppler US were performed in 100 consecutive patients. AGVD was defined as a venous structure that ascended parallel to the main portal vein and drained independently into segment IV. RESULTS: AGVDs were observed in eight of 100 patients (8%) with color and power Doppler US. Power Doppler US depicted these veins more clearly than did color Doppler US. Gray-scale US did not show any AGVDs. Two of eight patients with AGVDs detected by color Doppler US underwent celiac arteriography and CT during arterial portography (CTAP). In these two patients, celiac arteriography directly demonstrated AGVDs draining into segment IV, which revealed nontumorous perfusion defects (pseudolesions) on CTAP. CONCLUSION: Color and power Doppler US are useful imaging methods for demonstrating AGVDs.     

Action of phenolic antioxidants on various active oxygen species

The action of phenolic antioxidants, such as probucol, on various active oxygen species was investigated using luminol chemiluminescence and spin trapping with 5,5-dimethyl-1-pyrroline-N-oxide (DMPO). The various active oxygen species, including hydroxyl radicals (Fenton reaction), superoxide anions, singlet oxygen and hypochlorite ions were examined with phenolic antioxidants under aqueous and nonaqueous conditions. Probucol showed a quenching effect on both superoxide anions and hypochlorite ions in nonaqueous solution. However, it had no effect on hydroxyl radicals. alpha-Tocopherol, a natural phenolic antioxidant, showed a stronger quenching effect on superoxide anions and hypochlorite ions than probucol, and quenched hydroxyl radicals in nonaqueous solution. Furthermore, Trolox showed a quenching effect on all active oxygen species in both aqueous and nonaqueous solution. The antioxidants were studied under comparable conditions in a series of test systems and the reactivity profiles depicted as 'radar charts' which are helpful for characterizing antioxidant action.     

5-Azacytidine induces toxicity in PC12 cells by apoptosis

5-Azacytidine (5 Az)is a potent inhibitor of DNA methylation, and it may allow inactive genes to become expressed. In a previous study, we demonstrated that 5 Az administered to the dam induced apoptosis in the brains of fetal mice. In this study, the 5 Az-induced apoptosis was further characterized in differentiated PC 12 cells as a model for neuronal apoptosis. Cell death, determined by the activity of released lactate dehydrogenase (LDH) into the medium, occurred from 24 to 48 hrs after 5 Az treatment. Toxicity for differentiated PC 12 cells was observed on treatment with more than 10(-1) micrograms/ml of 5 Az, and it reached the maximal level at 10 micrograms/ml. Cycloheximide, an inhibitor of protein synthesis, prevented 5 Az toxicity, suggesting that this cell death required protein synthesis which could be related to the activation of a dormant gene(s). Electrophoresis of DNA from 5 Az-treated cells evoked ladder formation, indicating the cleavage of DNA into nucleosomes. Scanning electron microscopy demonstrated bleb formation, the so-called apoptotic bodies on the cell surface. The biochemical and morphological findings indicated that 5 Az-induced cell death occurred in the form of apoptosis. 5 Az-induced cell death was prevented by treatment with cAMP but not by treatment with high K+ or deoxycytidine. These results suggest that a cAMP-sensitive mechanism is involved in 5 Az-induced cell death. PC 12 cells should be of value in elucidating the molecular mechanism of 5 Az-induced neuronal apoptosis.     

Hyperparathyroidism--comparison of flash imaging with spin echo MR imaging

MR images of the neck were prospectively studied in 19 patients with hyperparathyroidism. Fast low angle shot (FLASH) sequence was performed in addition to T1- and T2-weighted spin echo (SE) sequences. FLASH images were obtained with 320/12/20 degrees (TR/TE/flip angle) using presaturation technique. TE of 12 ms was chosen to eliminate high signal of fat tissue. In the evaluation of detectability, a combination of T1-weighted SE and FLASH images (T1WI + FLASH) was compared with a combination of T1- and T2-weighted SE images (T1WI + T2WI). MR imaging correctly depicted 20 of 30 abnormal glands on both T1WI + FLASH and T1WI + T2WI. FLASH imaging effectively eliminated high signal of fat tissue. Nineteen abnormal glands demonstrated higher signal than surrounding tissues on FLASH images, whereas 12 glands were high-intense on T2-weighted SE images. We conclude that FLASH imaging provides improved tissue contrast and anatomic delineation and, thus, may replace T2-weighted SE imaging in the neck.