Less maintenance immunosuppression in lung transplantation following hematopoietic stem cell transplantation from the same living donor.

Living-donor lobar lung transplantation (LDLLT) is one of the final options for saving patients with pulmonary complications after hematopoietic stem cell transplantation (HSCT). We retrospectively investigated 19 patients who had undergone LDLLT after HSCT in Japan. Eight patients underwent LDLLT after HSCT in which one of the donors was the same living donor as in HSCT (SD group), while 11 received LDLLT from relatives who were not the HSCT donors (non-SD group). In the SD group, three patients underwent single LDLLT. The 5-year survival rate was 100% and 58% in the SD and non-SD groups, respectively. In the SD group, postoperative immunosuppression was significantly lower than in the non-SD group. Two patients died of infection and one died of post-transplant lymphoproliferative disease (PTLD) in the non-SD group, while only one patient died of PTLD 7 years after LDLLT in the SD group. Hematologic malignancy relapsed in two patients in the non-SD group. For the three single LDLLTs in the SD group, immunosuppression was carefully tapered. In our study, LDLLT involving the same donor as for HSCT appeared to have advantages related to lower immunosuppression compared to LDLLT from relatives who were not the HSCT donors.

25-Hydroxyvitamin D3 1alpha-hydroxylase and vitamin D synthesis.

Renal 25-hydroxyvitamin D3 1alpha-hydroxylase [1alpha(OH)ase] catalyzes metabolic activation of 25-hydroxyvitamin D3 into 1alpha, 25-dihydroxyvitamin D3 [1alpha,25(OH)2D3], an active form of vitamin D, and is inhibited by 1alpha,25(OH)2D3. 1alpha(OH)ase, which was cloned from the kidney of mice lacking the vitamin D receptor (VDR-/- mice), is a member of the P450 family of enzymes (P450VD1alpha). Expression of 1alpha(OH)ase was suppressed by 1alpha, 25(OH)2D3 in VDR+/+ and VDR+/- mice but not in VDR-/- mice. These results indicate that the negative feedback regulation of active vitamin D synthesis is mediated by 1alpha(OH)ase through liganded VDR.

Convergence of transforming growth factor-beta and vitamin D signaling pathways on SMAD transcriptional coactivators.

Cell proliferation and differentiation are regulated by growth regulatory factors such as transforming growth factor-beta (TGF-beta) and the liphophilic hormone vitamin D. TGF-beta causes activation of SMAD proteins acting as coactivators or transcription factors in the nucleus. Vitamin D controls transcription of target genes through the vitamin D receptor (VDR). Smad3, one of the SMAD proteins downstream in the TGF-beta signaling pathway, was found in mammalian cells to act as a coactivator specific for ligand-induced transactivation of VDR by forming a complex with a member of the steroid receptor coactivator-1 protein family in the nucleus. Thus, Smad3 may mediate cross-talk between vitamin D and TGF-beta signaling pathways.

Characterization of DNA synthesis and DNA-dependent ATPase activity at a restrictive temperature in temperature-sensitive tsFT848 cells with thermolabile DNA helicase B.

A temperature-sensitive mutant defective in DNA replication, tsFT848, was isolated from the mouse mammary carcinoma cell line FM3A. In mutant cells, the DNA-dependent ATPase activity of DNA helicase B, which is a major DNA-dependent ATPase in wild-type cells, decreased at the nonpermissive temperature of 39 degrees C. DNA synthesis in tsFT848 cells at the nonpermissive temperature was analyzed in detail. DNA synthesis measured by incorporation of [3H]thymidine decreased to about 50% and less than 10% of the initial level at 8 and 12 h, respectively. The decrease in the level of thymidine incorporation correlated with a decrease in the number of silver grains in individual nuclei but not with the number of cells with labeled nuclei. DNA fiber autoradiography revealed that the DNA chain elongation rate did not decrease even after an incubation for 10 h at 39 degrees C, suggesting that initiation of DNA replication at the origin of replicons is impaired in the mutant cells. The decrease in DNA-synthesizing ability coincided with a decrease in the level of the DNA-dependent ATPase activity of DNA helicase B. Partially purified DNA helicase B from tsFT848 cells was more heat sensitive than that from wild-type cells. Inactivation of DNA-dependent ATPase activity of DNA helicase B from mutant cells was considerably reduced by adding DNA to the medium used for preincubation, indicating that the DNA helicase of mutant cells is stabilized by binding to DNA.

Selective interaction of vitamin D receptor with transcriptional coactivators by a vitamin D analog.

The nuclear vitamin D receptor (VDR) is a member of a nuclear receptor superfamily and acts as a ligand-dependent transcription factor. A family of cotranscriptional activators (SRC-1, TIF2, and AIB-1) interacts with and activates the transactivation function of nuclear receptors in a ligand-dependent way. We examined interaction of VDR with these coactivators that was induced by several vitamin D analogs, since they exert differential subsets of the biological action of vitamin D through unknown mechanisms. Unlike other vitamin D analogs tested, OCT (22-oxa-1alpha,25-dihydroxyvitamin D3) induced interaction of VDR with TIF2 but not with SRC-1 or AIB-1. Consistent with these interactions, only TIF2 was able to potentiate the transactivation function of VDR bound to OCT. Thus, the present findings suggest that the structure of VDR is altered in a vitamin D analog-specific way, resulting in selective interactions of VDR with coactivators. Such selective interaction of coactivators with VDR may specify the array of biological actions of a vitamin D analog like OCT, possibly through activating a particular set of target gene promoters.

Purification and identification of p68 RNA helicase acting as a transcriptional coactivator specific for the activation function 1 of human estrogen receptor alpha.

The estrogen receptor (ER) regulates the expression of target genes in a ligand-dependent manner. The ligand-dependent activation function AF-2 of the ER is located in the ligand binding domain (LBD), while the N-terminal A/B domain (AF-1) functions in a ligand-independent manner when isolated from the LBD. AF-1 and AF-2 exhibit cell type and promoter context specificity. Furthermore, the AF-1 activity of the human ERalpha (hERalpha) is enhanced through phosphorylation of the Ser(118) residue by mitogen-activated protein kinase (MAPK). From MCF-7 cells, we purified and cloned a 68-kDa protein (p68) which interacted with the A/B domain but not with the LBD of hERalpha. Phosphorylation of hERalpha Ser(118) potentiated the interaction with p68. We demonstrate that p68 enhanced the activity of AF-1 but not AF-2 and the estrogen-induced as well as the anti-estrogen-induced transcriptional activity of the full-length ERalpha in a cell-type-specific manner. However, it did not potentiate AF-1 or AF-2 of ERbeta, androgen receptor, retinoic acid receptor alpha, or mineralocorticoid receptor. We also show that the RNA helicase activity previously ascribed to p68 is dispensable for the ERalpha AF-1 coactivator activity and that p68 binds to CBP in vitro. Furthermore, the interaction region for p68 in the ERalpha A/B domain was essential for the full activity of hERalpha AF-1. Taken together, these findings show that p68 acts as a coactivator specific for the ERalpha AF-1 and strongly suggest that the interaction between p68 and the hERalpha A/B domain is regulated by MAPK-induced phosphorylation of Ser(118).

A matrix attachment region (MAR)-binding activity due to a p114 kilodalton protein is found only in human breast carcinomas and not in normal and benign breast disease tissues.

A M(r) 114,000 protein (p114) that specifically binds to nuclear matrix attachment DNA (matrix attachment region, MAR) from a breast carcinoma cell line SK-BR-3 was purified to near homogeneity. p114 strongly binds to a wild-type A+T-rich MAR probe with high unwinding propensity with a dissociation constant (Kd) of 10(-9), while it exhibits substantially reduced binding to a mutated A+T-rich non-MAR probe, which lacks unwinding propensity. This binding specificity and affinity is similar to the previously cloned thymocyte-associated MAR-binding protein SATB1. By Southwestern blot analysis, the MAR-binding activity of p114 is detectable in human breast carcinomas but is undetectable in normal breast tissues, benign breast diseases, and immortalized epithelial MCF-10A cells. Thus, the MAR-binding activity of p114 is not merely reflecting cell proliferation, but it strongly associates with breast carcinomas. The p114 MAR-binding activity was found in all 43 human breast carcinoma specimens tested, without exception. Much stronger p114 MAR-binding activity was detected in poorly differentiated than well-differentiated carcinomas. p114 may be a reliable diagnostic and possibly prognostic marker for breast cancer.

CHIP buffers heterogeneous Bcl-2 expression levels to prevent augmentation of anticancer drug-resistant cell population.

Many types of cancer display heterogeneity in various features, including gene expression and malignant potential. This heterogeneity is associated with drug resistance and cancer progression. Recent studies have shown that the expression of a major protein quality control ubiquitin ligase, carboxyl terminus of Hsc70-interacting protein (CHIP), is negatively correlated with breast cancer clinicopathological stages and poor overall survival. Here we show that CHIP acts as a capacitor of heterogeneous Bcl-2 expression levels and prevents an increase in the anticancer drug-resistant population in breast cancer cells. CHIP knockdown in breast cancer cells increased variation in Bcl-2 expression levels, an antiapoptotic protein, among the cells. Our results also showed that CHIP knockdown increased the proportion of anticancer drug-resistant cells. These findings suggest that CHIP buffers variation in gene expression levels, affecting resistance to anticancer drugs. In single-cell clones derived from breast cancer cell lines, CHIP knockdown did not alter the variation in Bcl-2 expression levels and the proportion of anticancer drug-resistant cells. In contrast, when clonal cells were treated with a mutagen, the variation in Bcl-2 expression levels and proportion of anticancer drug-resistant cells were altered by CHIP knockdown. These results suggest that CHIP masks genetic variations to suppress heterogeneous Bcl-2 expression levels and prevents augmentation of the anticancer drug-resistant population of breast cancer cells. Because genetic variation is a major driver of heterogeneity, our results suggest that the degree of heterogeneity in expression levels is decided by a balance between genetic variation and the buffering capacity of CHIP.

Bile acid metabolism in isolated rat hepatocytes: studied by gas-liquid chromatography-mass spectrometry-selected ion monitoring.

Bile acid contents in isolated rat hepatocytes were determined by gas-liquid chromatography-mass spectrometry-selected ion monitoring with the use of deuterium-labeled internal standards. This allowed us first to monitor the actual amounts of not only major but also minor bile acid components present with sufficient sensitivity and specificity and to follow the changes of individual bile acids in cultured rat hepatocytes simultaneously. In freshly isolated rat hepatocytes, cholic and beta-muricholic acids were the major components, comprising 35 and 46% of the total bile acids, respectively. These two bile acids were found to be most actively synthesized during the first 2 h of incubation and continued to increase thereafter for up to 6 h (the end of the period studied). In contrast, chenodeoxycholic and alpha-muricholic acids, which are the precursors of beta-muricholic acid, showed slight increases only in the first hour of incubation and decreased thereafter. These results suggested that the conversion to beta-muricholic acid from chenodeoxycholic acid via alpha-muricholic acid occurred rapidly in cultured rat hepatocytes. The secondary bile acids such as deoxycholic, hyodeoxycholic, and 3 alpha, 12 beta-dihydroxy-5 beta-cholanoic acids declined steadily from the start of incubation, which supported the findings that further hydroxylation of these dihydroxy bile acids occurs in rat liver.

Purification of two DNA-dependent adenosinetriphosphatases having DNA helicase activity from HeLa cells and comparison of the properties of the two enzymes.

DNA-dependent ATPase activities in crude extracts prepared from HeLa cells were separated into five peaks designated Q1 to Q5 by FPLC Mono Q column chromatography. In our previous study, we observed that crude extracts prepared from xeroderma pigmentosum complementation group C (XP-C) cells contained no DNA-dependent ATPase activity at the peak position of Q1 and exhibited a broader peak with higher activity than normal Q2 at the peak position of Q2 [Yanagisawa, J., Seki, M., Ui, M., & Enomoto, T. (1992) J. Biol. Chem. 267, 3585-3588]. We have purified two DNA-dependent ATPases Q1 and Q2 from HeLa cells and characterized their properties in order to obtain a means to discriminate ATPase Q1 from Q2 in XP-C cells. The apparent molecular masses of Q1 and Q2 on SDS-polyacrylamide gel electrophoresis were 73 and 100 kDa, respectively. The two enzymes required a divalent cation for activity. DNA-dependent ATPase Q1 hydrolyzed ATP and dATP and Q2 hydrolyzed ATP preferentially among the nucleotides tested. Both enzymes preferred single-stranded DNA as a cofactor. The DNA-dependent ATPase activity of Q2 was inhibited by 90% in the presence of 200 mM NaCl, whereas that of Q1 was not affected by NaCl at concentrations up to 200 mM. Both enzymes had DNA helicase activity, that of Q1 being more resistant to NaCl than that of Q2. The DNA helicase activity of Q2 was about 150-fold higher than that of Q1, when compared with units of ATPase activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Bile acid metabolism in cirrhotic liver tissue--altered synthesis and impaired hepatic secretion.

Bile acid analysis of mild and severe cirrhotic liver showed that with the advancement of cirrhosis the concentration of chenodeoxycholic acid in liver tissue becomes higher, resulting in the lower ratio of cholic to chenodeoxycholic acid probably due to the progressive alteration of cholic and chenodeoxycholic acid synthesis with the advancement of liver cirrhosis. Bile acid analysis of paired liver and bile of severe cirrhosis showed that the ratio of cholic to chenodeoxycholic acid in liver was lower than that in bile or even with that in bile. This can be explained by postulating the impaired hepatic secretion of bile acids, especially chenodeoxycholic acid. The impaired secretion together with the relatively well preserved chenodeoxycholic acid synthesis results in the accumulation of chenodeoxycholic acid in liver tissue with cirrhosis.

The interval between flexible sigmoidoscopy screening examinations can be expanded beyond five years.

BACKGROUND/AIMS: As one of the methods for colorectal cancer screening, asymptomatic average-risk persons aged > or = 50 years are recommended to undergo flexible sigmoidoscopy screening every 5 years. We evaluate whether the interval between examinations can be extended beyond 5 years. METHODOLOGY: A total of 192 asymptomatic average-risk subjects were studied, all of whom had undergone a initial negative examination on a flexible sigmoidoscopy screening at age > or = 50 years and a second examination at least 3 years later. The study population was divided into three groups according to the interval between examinations, which was 3-5 years in Group A, 5-6 years in Group B, and 6-8 years in Group C. RESULTS: The incidence of neoplasms was compared among the three subjects groups, and it was found to be similar: 11/96 (11.5%) in group A, 4/55 (7.3%) in group B, and 5/41 (12.2%) in group C. All detected adenomas were less than 10 mm in diameter, and none contained a villous component or high-grade dysplasia. No cancers were found in the study. CONCLUSIONS: The results suggest that the interval for screening sigmoidoscopy may be extended beyond 5 years in persons showing negative results on an initial examination.

Video-assisted thoracic surgery for lung cancer in hemodialysis patients.

INTRODUCTION: In recent years, the number of hemodialysis patients has been continuously increasing. At the same time, the use of video-assisted thoracic surgery (VATS) for lung cancer has also increased. However, reports of the outcome of VATS in hemodialysis patients are still quite rare. METHODS: From 1995 to 2011, 14 patients with non-small cell lung cancer who were also receiving hemodialysis underwent lung resection by open thoracotomy or VATS at our institution. These patients were divided into two groups as follows: open (five men and four women, mean age: 68.7 years) and (2) VATS (three men and two women, mean age: 64.0 years). We compared the clinical outcomes of these two groups. RESULTS: Lobectomy was performed in eight patients in the open group, including one patient who also underwent a pneumonectomy, and in four patients in the VATS group, including one who also underwent a wedge resection. There were no significant difference between the groups' operation times, intraoperative blood loss, length of postoperative chest drainage, and length of postoperative hospitalization. There were no hospital deaths in either group. The 5-year survival rate was 42.9% in the open group and 37.5% in the VATS group. This difference was not significant (P=0.73). CONCLUSION: VATS lung resection for lung cancer patients on hemodialysis is considered an acceptable treatment modality, though the long-term survival rate of such patients is relatively low, which can be attributed to the diseases underlying the need for hemodialysis.

KLF4 suppresses estrogen-dependent breast cancer growth by inhibiting the transcriptional activity of ERalpha.

Kruppel-like factor 4 (KLF4) is a transcription factor that participates in both tumor suppression and oncogenesis. To determine the association of KLF4 with tumorigenesis, we integrated data assembled in the Oncomine database and discovered a decrease in KLF4 gene transcripts in breast cancers. Further analysis of the database also showed a correlation between KLF4 expression and estrogen receptor-alpha (ERalpha) positivity. Knockdown of KLF4 in MCF-7 cells elevated the growth rate of these cells in the presence of estrogen. Therefore, we examined the interaction between KLF4 and ERalpha, and found that KLF4 bound to the DNA-binding region of ERalpha. KLF4 thus inhibits the binding of ERalpha to estrogen response elements in promoter regions, resulting in a reduction in ERalpha target gene transcription. Earlier studies have reported that KLF4 is transcriptionally activated by p53 following DNA damage. We also showed that activation of p53 decreased the transcriptional activity of ERalpha by elevating KLF4 expression. Our studies discovered a novel molecular network between p53, KLF4 and ERalpha. As both p53 and ERalpha are involved in cell growth and apoptosis, these results may explain why KLF4 possesses both tumor suppressive and oncogenic functions in breast cancers.

Increased lysophosphatidylcholine and pancreatic enzyme content in bile of patients with anomalous pancreaticobiliary ductal junction.

A high incidence of inflammation and carcinoma of the biliary tract in patients with anomalous pancreaticobiliary ductal junction has been well documented. The change in biliary phospholipids as a result of the reflux of pancreatic juice into the biliary tract through anomalous pancreaticobiliary ductal junction may be responsible for it. We developed a new method of analysis of phospholipid classes using aminopropyl Bond Elut cartridge for extraction and high-performance liquid chromatography for separation. Satisfactory recovery was achieved (i.e., more than 95% for both phosphatidylcholine and lysophosphatidylcholine). With this method, the bile of 11 patients with anomalous pancreaticobiliary ductal junction was examined. The concentration and proportion of lysophosphatidylcholine in bile were much higher in the presence of anomalous pancreaticobiliary ductal junction than in controls (3.44 +/- 1.50 mmol/L vs. 0.52 +/- 0.25 mmol/L, 60.0% +/- 31.0% vs. 2.3% +/- 1.4% in gallbladder bile; p less than 0.001). In contrast, the concentration of phosphatidylcholine and the sum of phosphatidylcholine and lysophosphatidylcholine in gallbladder bile significantly decreased (p less than 0.001), but in hepatic bile they did not. An inverse correlation was found between the proportion of lysophosphatidylcholine and phospholipid concentration in gallbladder bile. Phospholipase A2 and amylase activities in bile were markedly high. Increased total fatty acid concentration and proportion of unsaturated fatty acid in bile were found. Total bile acid concentration in gallbladder bile was significantly lower than in controls. These results suggest that a considerable amount of lysophosphatidylcholine, which is known to have a cytotoxic effect, isp reduced by phospholipase A2 in refluxing pancreatic juice, and an increased concentration of lysophosphatidylcholine gives rise to cell damage causing mucosal hyperplasia and metaplasia.(ABSTRACT TRUNCATED AT 250 WORDS)

Altered metabolism of bile alcohol and bile acid in complete extrahepatic cholestasis: qualitative and quantitative aspects.

Urinary excretion of bile alcohols and bile acids in patients with complete extrahepatic cholestasis before and after the release by external biliary drainage was studied. Following extraction, isolation, and hydrolysis, bile alcohols were determined by capillary gas-liquid chromatography-mass spectrometry as dimethylethylsilyl derivatives. During cholestasis, 8.89 mumol/day of bile alcohol and 140.4 mumol/day of bile acid were excreted in urine. The amount of bile alcohol excreted was 6.1% of that of bile acid. Positive correlation between excretion of bile alcohols and bile acids was observed. The major bile alcohols excreted were also present in urine from healthy individuals but in much smaller amounts. After the release of extrahepatic cholestasis, urinary excretion of bile acid decreased rapidly, but that of bile alcohol decreased only gradually. The latter often increased again and remained high. The results indicate that the increased excretion of bile alcohols in complete extrahepatic cholestasis may reflect the expansion of a normally existing pathway of bile alcohol synthesis and excretion leading to the modification of bile alcohols for their efficient urinary elimination. It is also suggested that the rate of synthesis of bile alcohols is determined partly by the size of the substrate pool available.

Absorption of bile acids in dog as determined by portal blood sampling: evidence for colonic absorption of bile acid conjugates.

The intestinal phase of enterohepatic circulation, such as site and state of bile acid absorption, along the length of the intestinal tract has been speculated but not directly quantitated. In order to gain insight into the actual state of intestinal absorption of bile acid, the bile acid composition of portal blood from various segments of the intestinal tract was studied in dogs after loading endogenous bile acid by injection of caerulein. Total and unconjugated bile acids were determined with and without enzymatic hydrolysis, respectively. The amount of conjugated bile acids was calculated by subtracting unconjugated from total bile acids. Quantitation of cholic, chenodeoxycholic, deoxycholic and lithocholic acids and their conjugates was carried out by gas chromatography/mass spectrometry/selected ion monitoring with deuterated bile acids as internal standards. The major site of absorption of taurine-conjugated bile acid, a major conjugate form in the dog, was the distal small intestine. In addition, a considerable amount of cholic acid was found to be absorbed from the distal large intestine, the majority of which was still in the conjugated form. The pronounced absorption of the unconjugated secondary bile acid from the large intestine suggests the very active formation of the secondary bile acid in situ.

Composition of intrahepatic calculi. Etiological significance.

Gallstones in intrahepatic (N = 42) and extrahepatic (N = 22) bile ducts and gallbladder (N = 23) were subjected to chemical analysis modified to suit the analysis of brown pigment stones with the aim of determining if stone location at surgery influenced stone composition. Dimethylsulfoxide-acetone-1 N HCl (90:9:1, v/v/v) was used to dissolve gallstone specimens. Intrahepatic calculi were divided into two groups, ie, nine cholesterol stones and 33 brown pigment stones. Cholesterol stones in the intrahepatic bile ducts had a similar composition to those in the gallbladder and extrahepatic bile ducts, suggesting a similar pathogenesis wherever formed throughout the biliary tract. Intrahepatic brown pigment stones contained significantly less bilirubin (P less than 0.001) and more cholesterol (P less than 0.05) by chi-square analysis than brown pigment stones found in the extrahepatic bile ducts, suggesting that the site of formation affects stone composition and modifies stone pathogenesis.

Phospholipase activity in human bile.

To investigate the importance of bacterial infection in the formation of free fatty acids found in brown pigment gallstones, free fatty acids and phospholipase activity in hepatic bile, with or without the presence of bacterial infection, were compared. The concentration of free fatty acids in bile with bacterial infection [0.467 +/- 0.447 mg per ml (mean +/- S.D.)] was significantly higher than when bacterial infection was absent (0.073 +/- 0.041 mg per ml; p less than 0.01). However, there was no significant difference in the composition of free fatty acids in hepatic bile when bacterial infection was present. Biliary phospholipase activity was determined by counting [14C] palmitic acid released from [14C]dipalmitoyl phosphatidylcholine that was incubated with native bile. The biliary phospholipase activity was significantly higher when bacterial infection was present. Furthermore, a positive correlation (p less than 0.001) was found between the activity of biliary phospholipases and the concentration of free fatty acids in hepatic bile. Most bacterial strains isolated from bile were shown to have both phospholipase A1 and A2 activity. On the other hand, human pancreatic juice and human gallbladder epithelial cells contained mainly phospholipase A2. Since fatty acids in the gallstone are mainly palmitic acid and must have been cleaved from first position in the biliary phosphatidylcholine molecule, bacterial phospholipase A1 seems to play an important role in the formation of calcium palmitate found in brown pigment gallstones.

Effects of bile duct obstruction and decompression on hepatic microsomal mixed function oxidase system in rats.

The effects of biliary obstruction and drainage on the hepatic microsomal mixed function oxidase system were studied in rats. Bile duct obstruction produced a significant reduction in the hepatic cytochrome P-450 dependent mixed function oxidase system. After release of the bile duct obstruction, the reduction in microsomal enzymes was practically reversible; however, the process of recovery was slow and differed with the microsomal enzymes in question. Increases in cytochrome b5 content and NADH-cytochrome b5 reductase activity were slower than increases in cytochrome P-450 content and NADPH-cytochrome c reductase activity. Aniline hydroxylase activity increased more rapidly and corresponded to cytochrome P-450 contents more so than did the aminopyrine demethylase activity. After the release of bile duct obstruction, however, the bile acids which had accumulated in the liver during cholestasis were reduced rapidly, to a normal range. These results suggests that there is a discrepancy between reductions in hepatic bile acids and those in the hepatic microsomal mixed function oxidase system after biliary decompression.