Shouji Uetsuji

A SIMPLIFIED MODEL OF HYPOXIC INJURY IN PRIMARY CULTURED RAT HEPATOCYTES

SummaryThe Anaeropack system for cell culture, which was originally designed for the growth of anaerobic bacteria, was used to produce a hypoxic atmosphere for cultured hepatocytes. We measured changes in the oxygen and carbon dioxide concentrations and the atmospheric temperature in an airtight jar. We also measured changes in the pH of the medium during hypoxia to assess the accuracy of this system. Moreover, we used three durations (2, 3, and 4 h) of hypoxia and 8 h of reoxygenation in cultured rat hepatocytes, and then measured the lactate dehydrogenase (LDH), ketone body concentration (acetoacetate + β-hydroxybutyrate), and the ketone body ratio (KBR: acetoacetate/β-hydroxybutyrate) in the medium in order to assess the suitability of this system as a model for reperfusion following liver ischemia. The oxygen concentration dropped to 1% or less within 1 h. The concentration of carbon dioxide rose to about 5% at 30 min after the induction of the hypoxic conditions, and was maintained at this level for 5 h. No effect of the reaction heat produced by the oxygen absorbent in the jar was recognized. The extent of cell injury produced by changing the hypoxic parameters was satisfactorily reflected by the KBR, the ketone body concentration, and the LDH activity released into the medium. Because this model can duplicate the conditions of the hepatocytes during revascularization following ischemic liver, and the Anaeropack system for cell culture is easy to manipulate, it seems suitable for the experimental study of hypoxic injury and revascularization in vitro.

Prolonged decreases in plasma nitrate levels at early postoperative phase after hepato-pancreato-biliary surgery

Nitric oxide (.NO) is known to influence circulatory, neural, immunologic, and metabolic alterations. To evaluate the clinical significance of .NO production under surgical stress, serial measurements of plasma nitrite plus nitrate levels were performed in 45 surgical patients. Group A included 19 patients who underwent major surgery with uneventful postoperative courses. Group B included 18 patients who underwent laparoscopic cholecystectomy. Group C included 8 patients whose surgery was complicated by intra-abdominal abscesses. Eight healthy volunteers served as controls. Plasma nitrate levels were determined with a redox chemiluminescence .NO analyzer and coincided with measurements made by high-performance liquid chromatography (r = 0.868, p < 0.0001, 58 samples). During laparotomy, arterial nitrate levels correlated well with peripheral, portal, and hepatic venous nitrate levels (r = 0.966, 0.938, and 0.949, respectively; p < 0.0001). A significant decrease in nitrate from preoperative levels in groups A (postoperative day (POD) 1 and 3; p < 0.0005) and B (POD 1, p < 0.0001) was observed; nitrate levels in group C did not decrease for 14 days after surgery. Plasma nitrate levels in groups A and B were significantly different (POD 1 through 6, p < 0.05) and at POD 3 were significantly lower in group A (p < 0.005). Plasma nitrate levels measured before and after fasting or food intake were not significantly different. These results suggest that surgical stress leads to a decrease in the end product of .NO in the whole body, and that the greater the surgical stress the longer the duration of decreased .NO production.

Clinical Evaluation of a Low Junction of the Cystic Duct

The point of the junction of the cystic duct with the common hepatic duct was studied by means of various preoperative and intraoperative cholangiographic procedures and by gross intraoperative examinations in 468 surgical patients with biliary diseases. The cystic duct entered the hepatic duct at a very low position and was consequently long in 39 patients. The clinical significance of this abnormally low junction of the cystic duct was studied in comparison with 358 patients with gallstones with a normal cystic duct-hepatic duct junction. In the low-junction group with a short common bile duct several complications, including gallstone pancreatitis (7 patients), the Mirizzi syndrome (7), confluence stones (2), gallbladder cancer (3), and congenital dilation of the cystic duct (1), were demonstrated preoperatively. The anomalous junction of the cystic duct with the common bile duct may cause stagnation of bile and/or reflux of pancreatic juice into the bile duct, producing a choledochopancreatic ductal junction and posing difficulties at surgery.

Hepatocyte volume as an indicator of hepatic functional reserve in cirrhotic patients with liver tumours

Using computed tomography (CT), measurements of whole liver volume have been used for the assessment of pre‐operative functional reserve in cirrhotics. However, measurements of hepatocyte volume, which exclude stromal fibrous tissue, are considered to more directly reflect hepatic functional reserve. We investigated the relationship between total hepatocyte volume and each of the parameters of conventional liver function. Indocyanine green (ICG) tests and blood analyses for the assessment of liver function were performed prior to surgery in cirrhotic patients with liver tumours. Pre‐operative liver volume was determined by integrating images of each liver area obtained by CT. Liver area was measured by an image processing program that traced the profile of the liver image while excluding the tumorous area. Sections of normal tissue stained by the haematoxylin‐eosin method, were obtained from the resected liver. Using these sections, a hepatocyte area: whole tissue area ratio was calculated using the image processing program, by tracing the profiles of the hepatocyte nodules. The total volume of hepatocytes was then calculated by multiplying the liver volume by this ratio. The hepatocyte volume per unit bodyweight was significantly correlated with ICG tests and with many other parameters of normal liver function. However, the liver volume per unit bodyweight was correlated only with the plasma ICG disappearance rate and with the blood platelet count. These observations suggest that the functional reserve of the cirrhotic liver is assessed more precisely by hepatocyte volume than by liver volume.

Assessing the eligibility for liver transplantation of patients with fulminant hepatitis.

The spleen to liver volume (S/L) ratio of 13 patients with fulminant hepatitis was determined using X-ray computed tomography (CT), and the correlation between S/L ratio and prognosis was evaluated. The S/L ratio of 6 patients who died was greater than 0.16, whereas that of the remaining 7 patients who survived was less than 0.15. These findings suggest that determining the S/L ratio using CT may be useful for assessing the eligibility of patients with fulminant hepatitis for liver transplantation.