Fracture of the atlas through a synchondrosis of the anterior arch complicated by atlantoaxial rotatory fixation in a four-year-old child.

Fracture of the atlas is rare in children. We report a case of fracture of the atlas through a synchondrosis of the anterior arch complicated by atlantoaxial rotatory fixation in a four-year-old girl.

Effects of portal-systemic shunt following 90% partial hepatectomy in rats.

We studied the effects of portal-systemic shunt after massive hepatectomy. Male Wistar rats were divided into two groups: one group underwent laparotomy alone (C group) and in the other group a portal-systemic shunt was placed through laparotomy (S group). After 90% hepatectomy was performed, 3-day and 1-week survival rates and histopathology were examined, and hepatic hemodynamics during the early stage after hepatectomy were measured using dye-containing microspheres. The 3-day survival rate in the S group was significantly higher, and the 1-week survival rate was slightly higher, than those in C group. Sinusoidal dilation 7 days after hepatectomy in the S group was significantly milder than that in the C group. Fatty degeneration of hepatocytes in the S group was significantly milder than that in the C group. With respect to hepatic hemodynamics during the early stage after hepatectomy, the rate of shunt (26.3%) in the S group was significantly higher than that (9.5%) in the C group. Portal pressure, total hepatic blood flow, and total hepatic blood flow per gram of liver in the S group were significantly lower than those in the C group. These results suggest that approximately 26% shunt after 90% hepatectomy in rats increases the early survival rate and improves histological changes in surviving rats 7 days after resection.

Effect of portal hypertension caused by chronic high venous pressure on small-intestinal sugar absorption.

The effect of portal hypertension and chronic high venous pressure on the absorption of the small intestine was examined by constricting the suprahepatic and subdiaphragmatic inferior vena cava in rats. A group of rats with the constricted suprahepatic and subdiaphragmatic inferior vena cava comprised group 1 (n = 9) and another group of rats with only laparotomy comprised group 2 (n = 9). Two months after the operation, sugar absorption and other parameters were measured. The blood pressures of the infrahepatic inferior vena cava and the portal vein 8 wk after the operation in group 1 were significantly higher than those in group 2. The results of D-xylose absorption tests showed that the amount of excreted D-xylose in urine in group 1 was significantly lower than that of group 2, but the D-xylose everted sac test showed no significant differences between the two groups. The glucose everted sac test showed that the amount of glucose absorption in group 1 was significantly lower than that in group 2. These findings suggest that chronic high venous pressure caused by constriction of suprahepatic inferior vena cava may lead to sugar malabsorption. We conclude that portal hypertension with high venous pressure below the diaphragm can lead to sugar malabsorption in the intestine.

Influence of intermittent ischemia on thioacetamide-induced rat liver cirrhosis.

We studied the influence of intermittent ischemic injury on thioacetamide-induced liver cirrhosis in rats. Wistar rats were divided into group A, intermittent ischemic injury to liver cirrhosis, and group B, continuous ischemic injury to liver cirrhosis. Total ischemic time was 60 min in both groups. In group A, ischemic injury consisted of a repetition 4 times of 15 min ischemia and 5 min reperfusion. The ATP level of the liver was measured before ischemia, before reperfusion, and 60 min after reperfusion. Bile was collected to determine bile flow rate. The ATP level in the liver tissue 60 min after reperfusion was significantly (p < 0.05) higher in group A than in group B. The ATP level immediately before reperfusion was also significantly (p < 0.05) higher in group A than in group B. The survival rate 1 week after ischemic injury and bile flow rate 60 min after reperfusion were significantly (p < 0.01) higher in group A compared with those in group B. The energy level was much higher in intermittent ischemic injury than in continuous ischemic injury immediately before reperfusion and after reperfusion. Survival rate and bile flow rate were higher in intermittent ischemic injury than in continuous ischemic injury. Therefore it suggests that the viability of the liver was maintained better in intermittent ischemic injury than in continuous ischemic injury.

Evaluation of ischemic damage in the skeletal muscle with the use of electrical properties.

We performed experimental and clinical studies with measurement of electrical character in the skeletal muscle to assess ischemic damage and reperfusion injury in lower limbs. In 14 dogs, the bilateral hind limbs were squeezed at the inguinal region to make ischemia and they were reperfused after various intervals. Conductivity (G) of the skeletal muscles in hind limbs was measured with an LCR meter, which is an impedance analyzer. Change of G from 0 to 3 h of reperfusion (Delta3G) was calculated. G was decreased during ischemia and increased after reperfusion. In those whose Delta3G as more than 2.1 mS/cm, serum creatine kinase and aldolase at 10 h after reperfusion were correlated significantly (P < 0.01) to Delta3G. In patients with an abdominal aortic aneurysm (N = 3), arteriosclerosis obliterans (N = 1), or acute arterial occlusion (AAO, N = 1), G of lower extremities was measured from arterial clamp to declamp. Conductivity markedly increased after reperfusion and serum creatine kinase was the highest in the patient with AAO. We suggested that measurement of G may provide monitoring of ischemic and reperfused phase injury in the skeletal muscle and may be applicable to prediction of the skeletal muscular reperfusion injury.

[A case of esophageal leiomyoma found as mediastinal tumor, diagnosed with endoscopic ultrasonography].

A 20 year-old female was admitted to our department because of an abnormal shadow in chest roentgenogram on a physical check-up. The barium swallowing study revealed an oppression of the middle of the esophagus. Endoscopy, chest CT and MRI failed to distinguish submucosal tumor from mediastinal tumor. Endoscopic ultrasonography showed the mass originated from the esophagus and a diagnosis of esophageal smooth muscle tumor was obtained. The tumor was tried to resect by thoracoscopic surgery but was failed because of its shape like a tortoise shell. The tumor was resected through the right thoracotomy and the diagnosis was confirmed histopathologically.

Evidence of direct recognition subset in xeno-reactive helper T cells.

There are two functional subsets of alloreactive helper T cells: one recognizes the alloantigens on self-antigen-presenting cells (APCs), and the other recognizes the alloantigens on allo-APCs. In this study, we analyzed which specific Th cells have a possible effect on concordant-xenograft rejection responses and how Th cells recognize xeno-antigens. In the proliferative response stimulated with spleen cells obtained from rats (r-SPC), mouse T cells (m-Tc) were not inhibited by GK1.5 (CD4) or 2.43 (CD8) antibodies. In a xeno-mixed lymphocyte reaction, m-Tc that included APC (APC(+)) proliferated when stimulated with r-SPC APC(+) or APC(-). In contrast, B6 T cell APC(-) proliferated only when stimulated with r-APC(+)SPC but not when stimulated with APC(-). The m-Tc lines responded to F344 SPC APC(+) but not to SPC APC(-); however, the m-Tc line did not respond to SPC from another rat strain. We hypothesize that both CD4+ Th and CD8+ Th are included in the concordant xeno-reactive Th; there are both xeno-APC-restricted Th and self-APC-restricted Th; and xeno-APC-restricted Th recognizes xeno-major histocompatibility complexes.

Influence of CO2 tension on hepatic hemodynamics during portal arterialization.

We investigated the effect of portal arterialization (PA) on hepatic energy metabolism and hepatic hemodynamics. Portal perfusion flow rate with arterial blood was 25% of the preperfusion portal flow. During PA up to 120 min, hepatic energy metabolism was maintained from the aspects of ATP, energy charge, and arterial ketone body ratio. However, during this PA, carbon dioxide tension (25-35 mm Hg) in arterial blood was lower than that in normal portal vein blood and portal vein resistance (PVR) was significantly increased during perfusion compared with that at preperfusion. When carbon dioxide tension (50-63 mm Hg) in arterial blood was made equivalent to that in normal portal vein blood by controlling the respiratory conditions, PVR was not increased during PA up to 120 min. It was suggested that PCO2 in perfusion blood should change PVR, while it should not change hepatic energy metabolism when portal perfusion flow rate with arterial blood was 25% of the preperfusion portal flow.

Dielectric spectrogram for instantaneous evaluation of ischemic injury of the liver.

Electrical properties of tissues sensitively reflect structural and physiologic changes. The authors examined the use of a dielectric spectrogram for instantaneous evaluation of ischemic injury of the liver. Wistar rats, which had enough collateral circulation for portal bypass with subcutaneous transposition of the spleen, were used. Four ischemic periods (15, 30, 60, and 120 min) were examined and followed by reflow. Permittivity and conductivity were measured at 39 frequency points in the 20 Hz-1 MHz range using an LCR meter system. They were then expressed in a loss tangent (LT) plot to clear their behavior. The maximum LT value (max-LT) and the minimum LT value (min-LT) of the normal liver were 3.98 +/- 0.28 and 2.98 +/- 0.22, and appeared in 15-20 kHz and 150-300 kHz, respectively. During the first 30 min after ischemia, max-LT decreased to 3.25 +/- 0.14 (p < 0.005) and its range shifted to 0.3-0.6 kHz, and min-LT decreased to 1.35 +/- 0.06 (p < 0.001) without shifting of range. Max-LT then decreased gradually and min-LT began to increase. After reflow, max-LT increased and higher max-LT was observed in the longer ischemic cases. Max-LT at 1 hr after reflow correlated negatively with recovery rate of bile flow at that time (y = -0.238x + 1.84, r2 = 0.82). Additionally, the difference between max-LT and min-LT at just before reflow (dif-LT) showed a significant correlation coefficient with recovery rate of bile flow at 1 hr after reflow (y = 2.22x -3.32, r2 = 0.92).

Clinical study on hepatocellular carcinoma with extrahepatic malignancies.

In a consecutive series of 146 patients with hepatocellular carcinoma (HCC), 10 patients (6.8%) were found to have one or two extrahepatic malignancies (EHM). Of these, eight had double cancers and two, triple cancers. The associated malignancies included eight cases of gastric cancer and four cases of colon cancer. Among the 12 lesions, eight were in the early stage. All the 10 patients were hepatitis B surface antigen negative. The incidence of coexisting liver cirrhosis and the retention rate of indocyanin green in 15 minutes among HCCs with EHM were significantly lower than those among HCC alone. These results suggest that the etiology of HCC with EHM is different from the etiology of HCC alone in Japan.

[Changes in high energy phosphates and tissue blood flow in ischemia and reperfusion of jaundiced rat liver--effect of intermittent brief ischemia].

This study was focused on the changes of high energy phosphates and tissue blood flow (TBF) in ischemia and reperfusion, of jaundiced rat liver. We ligated and cut the bile duct of male Wistar rats to induce jaundice. The rats were divided into two groups, BDL-4W which had ligation four weeks before examination and control which had no ligation. Two studies were performed; In study A, ischemia was induced by clamping portal vein and hepatic artery for 60 minutes. In study B, 15 minutes of ischemia was repeated four times with intervals of 10 minutes of reperfusion. A: 1) In BDL-4W, ATP was significantly lower than that in control at pre-ischemia and reperfusion. Recovery ratios (RR) of ATP in BDL-4W were significantly lower than those in control. 2) RR or TBF in BDL-4W were significantly lower than those in control. 3) In BDL-4W, xanthine was significantly higher than that in control at reperfusion. B: 4) There were no significant differences in the RR of ATP after reperfusion between two groups. 5) There were no significant differences in the RR of TBF between two groups. 6) There were no significant differences in xanthine after reperfusion between two groups. We concluded that intermittent brief ischemia was useful when 60 minutes of ischemia was required for the operation of jaundiced liver.

A skeletal muscle actuator for an artificial heart.

The authors developed a system to use skeletal muscle as an artificial heart actuator. This system consists of a flexible rod, sheath, crank, and cam to transmit the muscle power to a pusher plate pump and actuate it. The latissimus dorsi muscle was dissected at the lower ribs, and its end was connected with the flexible rod. The contraction of skeletal muscle was linearly transmitted, with the rod introduced inside the sheath, to the pump. The whole system was implanted in dogs (14-18 kg) and pump performance was evaluated with a mock circulatory system (preload = 10 mmHg, afterload = 75 mmHg). In these experiments, the pump output was maintained at 0.8 to 2.0 L/min (60 bpm) for 200 min, with a non-preconditioned muscle that was stimulated continuously. The output obtained was 2.5 mW/gram. Efficiency of this system was about 50% of the muscle power available. When the muscle was stimulated intermittently every 30 min, pump flow was maintained at > 0.8 L/min for 20 hr. Advantages of this system are: 1) the muscle power was linearly transmitted effectively, 2) this system could be installed with minimal surgery and without interruption in blood flow to the muscle, 3) the muscle is free from high intraventricular pressure that caused ischemia and, 4) the muscle can be set to the proper length in diastole to potentiate strong contractions.

[Changes of plasma amino acid profiles following total hepatectomy under veno-veno bypass in dogs].

Patients with advanced liver disease demonstrate characteristic plasma amino acid abnormalities. The response of plasma amino acid patterns after liver transplantation in those patients is unknown. Mongrel dogs were subjected to two experimental models, that is, one is total hepatectomy under veno-veno bypass as an assumption of an hepatic phase in liver transplantation and the another is splenectomy as control. In control group, BCAA/AAA ratio rose gradually during operation. The levels of methionine, glycine and alanine were significantly lower at 4 hours. In hepatectomized dogs, BCAA/AAA ratio fell gradually after total hepatectomy. The levels of amino acids except BCAA were higher than preoperative value. Increase of alanine was the most remarkable early after total hepatectomy. It was derived not only from the lack of glucose-alanine cycle but also from increased synthesis due to degradation of the BCAA in muscle.