Determination of cytochromes in human liver contaminated with hemoglobin

A spectrophotometric method was developed to determine cytochromes in human liver mitochondria contaminated with hemoglobin. The influence of hemoglobin on the measurement was canceled by keeping hemoglobin in the carbon monoxide bound form throughout determination. Mitochondria were solubilized by 2% sodium cholate, and cytochromes were reduced enzymatically with glutamate and succinate as substrates to the maximal extent. The amount of cytochromes determined spectrophotometrically was linearly correlated with mitochondrial protein at least up to the extent of 8 mg/ml.

Arterial blood ketone body ratio as an indicator of the no-return point in hepatic inflow occlusion without venous shunt in dogs

The effects of hepatic inflow occlusion without venous shunt on the viability of the liver were investigated with respect to liver energy metabolism in dogs, subjected to portal triad cross-clamping (Pringle's maneuver) for 10, 30 and 60 min. The concentrations of ketone bodies and the arterial blood ketone body ratio (KBR) were decreased markedly by hepatic inflow occlusion, but recovered upon recirculation. The initial velocity of KBR recovery was 0.150/min after 10-min clamping, 0.140/min after 30-min clamping and 0.032/min after 60-min clamping. KBR recovery was delayed when hepatic inflow occlusion exceeded 30 min, which indicates that hepatic inflow occlusion for 60 min causes severe inhibition of energy generation in liver mitochondria. These findings indicate that the safety period for hepatic inflow occlusion without venous shunt is between 30 and 60 min in dogs, and that mortality can be predicted by measuring the initial velocity of KBR recovery upon recirculation.

A simple and direct approach to the portal triad structures for a left lobectomy or a left lateral segmentectomy

The hilar isolation and dissection of portal pedicle is usually performed prior to hepatectomy in order to minimize blood loss intraoperatively. In some instances, it is difficult to visualize and encircle the bifurcation of the portal triad structures. We recommend the use of a simple and safe method of direct approach to the transverse portion of the portal vein in the left lobectomy or lateral segmentectomy, by incision and dissection of the ligament teres hepatis and continuing fatty tissue.

The influence of hemodilution in normal and cirrhotic rats in relation to hepatic energy metabolism

The effects of acute hemodilution on hepatic energy status were compared between carbon-tetrachloride-induced cirrhotic rats and normal rats, using arterial blood ketone body ratio and hepatic energy charge as indices. Arterial blood was withdrawn and replaced with rat plasma in hemodiluted rats and with whole blood in sham-diluted control rats. In normal rats, arterial blood ketone body ratio and energy charge level at 6 hours after hemodilution decreased when the hematocrit value was less than 15%. In contrast, the values decreased at an even higher hematocrit level in cirrhotic rats. It was suggested from these results that the hemodilution procedure exerts a more profound hypoxic effect at a milder hemodilution on a cirrhotic liver than on a normal liver.

Fluorometric study for the noninvasive determination of cellular viability in perfused rat liver

Pyridine nucleotide fluorescence in perfused rat liver for the noninvasive determination of donor graft viability was investigated in relation to other metabolic indices, such as NAD concentration, adenine nucleotides, and mitochondrial phosphorylative activity. The amplitude between oxidation and reduction levels (RxA) in fluorometric trace, and the slope or the velocity of the trace curve from oxidation to reduction (RxV) were determined by the measurement of fluorescence from NAD(P)H, using a new fluorometric device, RxA and RxV decreased proportionally to the duration of preservation period (6, 12, 24, 48 hr) in simple cold storage. Other values of hepatic cell viability, such as total adenine nucleotides, energy charge, and mitochondrial phosphorylation rate, were simultaneously measured and also decreased proportionally to the duration of preservation period. There were close positive correlations between the percentage of RxA and NAD concentration (r = 0.724, p less than 0.01), between the percentage of RxA and total adenine nucleotides (r = 0.887, p less than 0.01), between the percentage of RxV and energy charge (r = 0.715, p less than 0.01), and between the percentage of RxV and phosphorylation rate/cytochrome a(+a3) (r = 0.837, p less than 0.01). These results suggest that this fluorometric method can provide an accurate noninvasive evaluation of donor graft viability--and, unlike the present indices of energy metabolism, it may be applied to evaluate the primary nonfunctioning graft prior to transplantation.

Metastatic nodules of hepatocellular carcinoma: detection with angiography, CT, and US

Accurate detection of intrahepatic metastases, or daughter nodules, of primary hepatocellular carcinoma is of crucial importance. Due to the introduction of infusion hepatic angiography, computed tomography (CT) after Lipiodol (iodized oil) infusion, and intraoperative ultrasound (US), tumors less than 10 mm in diameter are now frequently found. We compared the diagnostic accuracy of these three modalities in the detection of nodules in 45 patients who had hepatocellular carcinoma (confirmed by biopsy). CT with Lipiodol was superior to hepatic angiography in demonstrating nodules when they were overlapped by the primary tumor or very small in size. Intraoperative US demonstrated nodules in four avascular or hypovascular hepatocellular carcinomas, which both hepatic angiography and CT failed to demonstrate. In cases associated with severe liver cirrhosis, differentiation of small nodules from regenerating cirrhotic nodules was sometimes difficult with intraoperative US. The combined use of these three modalities is indispensable for the accurate detection of small nodules of metastatic hepatocellular carcinoma.

Influence of hemodilution on hepatic energy metabolism in rat

The effects and safety limits of acute hemodilution on hepatic energy status were investigated in relation to arterial blood ketone body ratio and hepatic energy charge in a hemodilution rat model. As long as the hematocrit value was maintained above 20%, ketone body ratio and energy charge level at 6 h after hemodilution remained at the same levels as those of the sham-diluted groups. However, when hematocrit value was less than 15%, the ketone body ratio markedly decreased from the control value of 0.686 +/- 0.044 to 0.278 +/- 0.048 (p less than 0.001), and energy charge decreased from the control value of 0.856 +/- 0.012 to 0.0806 +/- 0.011 (p less than 0.01). From these results, it was suggested that hemodilution exerts no influence on the energy status of the liver as long as hematocrit is maintained above 20%.

Low-melting phenytoin prodrugs as alternative oral delivery modes for phenytoin: a model for other high-melting sparingly water-soluble drugs

Phenytoin is a high-melting, weakly acidic, and sparingly water-soluble drug. Because of these physicochemical properties, phenytoin is subject to erratic bioavailability in a variety of dosage forms both in its acidic as well as sodium salt forms. A homologous series of 3-acyloxymethyl derivatives of phenytoin (acetyl through decanoyl) were synthesized and various physicochemical properties measured. The prodrugs were more readily soluble in various metabolizable glycerol esters such as tributyrin, trioctanoin, and triolein than phenytoin. The solubility of the prodrugs in the various organic vehicles studies was closely correlated to the melting point of the prodrug: the lower the melting point the greater the solubility. The cleavage rates of the prodrugs in plasma and tissue homogenates followed a parabolic relationship with chain length. The prodrug, 3-pentanoyloxymethyl-5,5-diphenylhydantoin when administered in tributyrin gave superior oral phenytoin bioavailability in rats when compared with sodium phenytoin administered as an aqueous solution.

Effects of hypertonic mannitol on renal function in open heart surgery

An extracorporeal bypass was performed in mongrel dogs for 2 hours with or without hypertonic mannitol infusions. In animals given mannitol, the plasma osmolality was elevated maximally to 344 +/- 7.1 mOsm/L and the urine volume was maintained well during bypass. A hypertonic mannitol solution was effective in maintaining the CPAH during and after bypass, but was not effective in minimizing the reduction in Ccr. When the mean arterial pressure during bypass was kept at 60 mmHg, the carbon filling rates in glomeruli showed the favorable effects of mannitol upon renal function, but no effects were observed at a mean arterial pressure of 80 mmHg. In 11 patients who had undergone a bypass lasting more than 2 hrs with mannitol infusions, the plasma osmolality reflected the serum mannitol level and reached 320 +/- 11.0 mOsm/L at 150 min of bypass. The mean urine volume was 5.0 +/- 3.3 ml/min/M2 during the bypass, which was about 7 times as great as before the bypass. The Ccr increased during the first 30 min of the bypass, but it fell to about one half of the initial value after 90 min of the bypass. It was concluded that a hypertonic mannitol solution is effective in maintaining the RPF and urine volume during and after the bypass and that it also preserved the glomerular perfusion even at a low arterial pressure.

Pulsatile venous flow in extracorporeal circulation

Effects of pulsatile venous flow upon the microcirculation were investigated in conditions with different venous pressures by using regional perfusion in dog's hind legs. In animals with venous pressure of -18 cmH2O (Collapsed stage), venous pulsation brought about a significant increase in mean oxygen consumption ratio and suppressed a rise of mean resistance ratio significantly. In animals with venous pressure of +2 cmH2O (normal venous pressure stage), the venous pulsation was effective in a rise of mean oxygen consumption ratio but was not effective in suppression of mean resistance ratio. In animals with venous pressure of +10 cmH2O (congestive stage), no effect of venous pulsation was recognized. We suppose that the intermittent elevation of venous pressure by venous pulsation is effective for opening some capillaries in animals with venous pressure below +2 cmH2O.

Circulating hepatodepressant factors decreasing the energy charge levels of the remnant liver after hepatectomy

In 25% hepatectomized rabbits, the mitochondrial phosphorylative activity and the energy charge [(ATP + 1/2 ADP)/(ATP + ADP + AMP)] levels of the remnant liver remained unchanged after hepatectomy. In 70% hepatectomized rabbits, the energy charge levels of the remnant liver decreased maximally 24 h after hepatectomy (p less than 0.001), simultaneously with a marked enhancement of mitochondrial phosphorylative activity (P less than 0.001). Afterward, both returned to normal levels within 4 days. In 93% hepatectomized rabbits, the energy charge levels fell rapidly, with an inhibition of mitochondrial phosphorylative activity, within 6 h after hepatectomy. When a 24-hour 70% hepatectomized rabbit was cross-circulated with a normal rabbit, the energy charge in the liver of the normal partner decreased to 0.732 at 30 min after the blood exchange and then returned to 0.855 while that in the remnant liver of the hepatectomized partner increased from 0.767 to 0.820 (p less than 0.001). Also, the energy charge values of a 24-hour 70% hepatectomized rabbit were increased by the extracorporeal normal liver perfusion. It is suggested that a decrease in the energy charge of the remnant liver is due, at least partly, to the accumulation of the substances consuming hepatic energy (hepatodepressant factors) in the systemic blood of hepatectomized rabbits.

Surveillance and follow-up of patients with implanted cardiac pacemaker by telephone transmission

A follow-up study on pacemaker function in 15 patients with implanted cardiac pacemaker has been performed by telephone transmission. The transmitting set consisting of electrocardiograph, pacemaker pulse modulator and acoustic coupler was manipulated by the patients themselves. ECG, pacemaker pulse, and pulse rate were simultaneously transmitted through 1 channel to the receiver in our clinic. Of 56 patients with pacemaker, 15 patients were surveyed by telephone transmission. In these patients battery exhaustion was detected in 3, competition in 2, and lead fracture in 1. The fact that surveillance and follow-up of the patients with implanted cardiac pacemaker could be carried out by telephone transmission as well as by clinic visitation tells us that the telephone transmission is a useful method and plays an important role in a pacemaker clinic. Moreover our study established its further usefulness in the patient's preference due to difficulties in travelling to the pacemaker clinic and in reducing patient's anxiety.

Role of portal venous blood supply from the pancreas in maintaining hepatic functional reserve. Appraisal of Warren's shunt operation

Mitochondrial phosphorylative activity was measured in the livers of various shunted or pancreatectomized dogs. In simple portal vein branch-ligated dogs, the mitochondrial phosphorylative activity in the nonligated lobe, which was supplied with excess portal blood, increased to approximately 150% of control values. In splenocaval-shunted or totally pancreatectomized dogs, the mitochondrial phosphorylative activity did not increase even in the nonligated lobe. However, the mitochondrial phosphorylative activity in the nonligated lobe increased to 120% of control in 80%-pancreatectomized and 150% in 50%-pancreatectomized dogs. In distal splenorenal-shunted (Warren-shunted) dogs, the mitochondrial phosphorylative activity increased to 150% of control values. Thus, the Warren's shunt operation is considered to be the more reasonable procedure for treatment of liver cirrhosis with esophageal varices, from the point of view of hepatic functional reserve based on the energetic metabolism of the liver.

Effect of insulin on mitochondrial oxidative phosphorylation and energy charge of the perfused guinea pig liver

The effect of insulin was investigated in the isolated guinea pig liver perfused with Krebs-Ringer bicarbonate buffer containing red blood cells and albumin. In the mitochondria isolated from livers perfused with 10 units of insulin per hour, the phosphorylative activity with glutamate as a substrate increased to about 160 per cent of control 60 minutes after the beginning of perfusion (p less than 0.01). Such an enhanced phosphorylative activity was accompanied by increases in the respiratory control ratio, state 3 respiration, and P/O ratio. On the other hand, in the liver perfused with insulin, the levels of the energy charge and adenine nucleotide quotient increased to a significant degree as compared to the liver without insulin (p less than 0.01 and p less than 0.05, respectively). It is suggested that insulin plays an important role as a portal factor in regulating mitochondrial oxidative phosphorylation and the levels of the phosphorylated adenine nucleotides.

Oral glucose tolerance in patients with jaundice

A glucose tolerance test was performed on 21 patients with jaundice. The glucose tolerance patterns were principally classified into a parabolic pattern characterized by the return toward normal within 120 minutes and a linear pattern with long-standing increase for more than 120 minutes. Of these, 13 patients showed the parabolic pattern and tolerated the operation well. The other eight patients showed the linear pattern. Of the latter, four patients died within three weeks postoperatively, and the others died without leaving the hospital following operation. From the results, it was suggested that the parabolic glucose tolerance pattern is indicative of compensated damage to the liver, while the linear glucose tolerance pattern shows critically decreased hepatic functional reserve. Experimentally, the close relationship between the severity of the derangement of metabolism in the mitochondria of the liver and the degree of glucose intolerance was studied in rats and rabbits with jaundice subjected to the ligation of the common bile duct. In rats with jaundice in which the phosphorylative activity is significantly higher than that in the mitochondria from the tissues of the liver deprived of endogenous insulin through portal blood, the parabolic patterns develop. In rabbits with jaundice in which the phosphorylative activity is considerably lower than that in the mitochondria from tissues of the liver deprived of endogenous insulin, the linear pattern occurs. It was suggested that the two distinct patterns in patients with jaundice are closely related to the severity of the derangement of the phosphorylative activity of the mitochondria.

Clinical application of cytochrome a(plus a3) assay of mitochondria from liver specimens: an aid in determining metabolic tolerance of liver remnant for hepatic resection

Measurement of cytochrome a(+a(3)) contents in liver mitochondria was made on 52 biopsy specimens of patients with liver tumor. Patients having higher cytochrome a(+a(3)) contents in mitochondria from remaining liver than those of normal human liver mitochondria could survive well major liver resections whether or not associated with liver cirrhosis. However, patients with cytochrome a(+a(3)) contents less than 0.5 x 10(-10) moles per mg protein showed a high rate of postoperative complication (80%) and death (40%) in spite of minor operation. In routinely used liver function tests such as serum albumin, A/G ratio, SGOT, total bilirubin, prothrombin time, BSP and TTT, there were no significant differences between patients with cytochrome a(+a(3)) contents more than 0.5 x 10(-10) moles per mg protein and those less than 0.5. The results indicate that routine laboratory studies do not have much diagnostic value in estimation of a marked decrease of mitochondrial cytochrome a(+a(3)) contents. It is suggested that the measurements of cytochrome a(+a(3)) of the remnant liver should be done prior to a contemplated major resection.