Regulation of renal cytochrome P450s by thyroid hormone in diabetic rats

Effects of thyroid hormone treatment on renal P450 expression in the diabetic rats were investigated. Diabetes produced by streptozotocin induced CYP4A2 and P450 K-2 (similar form with CYP2C23) but not P450 K-4 (similar form with CYP4A8) and induced lauric acid hydroxylation activity. The serum thyroid hormone level was decreased with diabetes. Treatment of diabetic rats with thyroid hormone (T3) as well as with insulin reversed the increase in the levels of CYP4A2 and P450 K-2. Thyroidectomy also induced CYP4A2 and P450 K-2 in the rat kidney. The increase was reversed by treatment of thyroidectomized rats with T3. These findings suggest that expression of CYP4A2 and P450 K-2 in rat kidney is suppressively regulated by thyroid hormone and the decrease in thyroid hormone level in the diabetic state affects the levels of CYP4A2 and P450 K-2.

Complete cDNA sequence and cDNA-directed expression of CYP4A11, a fatty acid omega-hydroxylase expressed in human kidney

A cDNA was isolated from a human kidney lambda gt10 library using the rat CYP4A3 cDNA as a probe. The cDNA-deduced amino acid sequence encoded a protein of 519 amino acids that was designated CYP4A11 (Nelson et al., 1993) and exhibited 76%, 72%, 80%, and 53% similarities to rat CYP4A1, rat CYP4A3, rabbit CYP4A6, and human CYP4B1, respectively. The deduced amino-terminal amino acid sequence of this cDNA agreed with the amino-terminal amino acid sequence of a major P450 protein purified from human renal microsomes. A second variant form of CYP4A11 cDNA, designated CYP4A11v, was isolated from the same library and had a deletion of a single adenine residue, thereby extending the reading frame and resulting in a protein of 591 amino acids. CYP4A11v is probably encoded by a rare allelic variant of CYP4A11, since no mutant alleles were uncovered in 15 normal individuals, as determined by a polymerase chain reaction (PCR) diagnostic test. Baculovirus-mediated cDNA expression of CYP4A11 yielded a P450 protein having a lambda max of 452 nm when reduced and complexed with carbon monoxide. The expressed enzyme efficiently catalyzed omega-hydroxylation of lauric acid. No detectable activity was uncovered toward arachidonic acid and prostaglandin E1. The cDNA-expressed variant, CYP4A11v, was found to be unstable and not to efficiently metabolize lauric acid, as assessed by both baculovirus and monkey kidney COS cell cDNA expression systems. These studies indicate that CYP4A11 is a major fatty acid-metabolizing P450 that is expressed in human kidney.

Increased CYP1A2 content and capacity to activate Glu-P-1 and Trp-P-2 in liver microsomes of scorbutic ODS rats

Osteogenic Disorder Shionogi (ODS) rats, which cannot synthesize ascorbic acid due to a deficiency of L-gulonolactone oxidase, become scorbutic when not supplied with dietary ascorbic acid. We used the deficient rats to study the effects of ascorbic acid on the amount of cytochrome P450 enzymes in liver microsomes. The total amount of hepatic cytochrome P450 in ODS rats deprived of ascorbic acid was lower by approximately 40%, whereas ODS rats fed with ascorbic acid and the wild strain had the same level of total hepatic cytochrome P450. Western blot analysis for various forms of cytochrome P450 in liver microsomes indicated that the amount of CYP1A2 was significantly higher in ascorbic acid deficient rats. On the other hand, amounts of CYP2B2 and 3A were lower, and those of CYP2E1 and CYP2C6/11 were unaffected. In accordance with the higher amount of CYP1A2, Northern blot analysis showed increased expression of CYP1A2 mRNA. The capacity of microsomes to produce mutagens from 2-amino-6-methyl-dipyrido[1,2-a:3',2'-d]imidazole acetate (Glu-P-1) and 3-amino-1-methyl-5H-pyrido[4,3-b]indole acetate (Trp-P-2) was higher in scorbutic ODS rats by the Ames test. These results indicate that the effects of ascorbic acid deficiency on the expression of cytochrome P450 in ODS rat livers are form-specific and that the increased CYP1A2 is associated with increased metabolic activation of promutagens in the scorbutic state.

Characterization of two P-450 isozymes placed in the rat CYP2D subfamily

Two P-450s with debrisoquine 4-hydroxylation activity, designated P-450 UT-7 and UT-7b, were purified and partially purified, respectively, from hepatic microsomes of untreated male rats. Both purified P-450s with an apparent molecular weight of 49,000, were associated with another protein with an apparent molecular weight of 29,000 which was designated 29 k-protein. The CO-reduced spectra of both P-450 UT-7 and UT-7b showed a peak at 448 nm. The NH2-terminal amino acid sequences of P-450 UT-7 and UT-7b were the same as the amino acid sequences of CYP2D1 and CYP2D2 deduced from the cDNA, respectively, except for the lack of a terminal methionine for P-450 UT-7b. In a reconstituted systems, P-450 UT-7 and UT-7b catalyzed lidocaine 3-hydroxylation and N-deethylation in the presence of the 29 k-protein. The Km and Vmax values for lidocaine 3-hydroxylation were 3.6 microM and 0.50 nmol/min/nmol of P-450 for P-450 UT-7, and 3.6 microM and 0.93 nmol/min/nmol of P-450 for P-450 UT-7b, respectively. Antibody against P-450 UT-7, which also cross-reacted with P-450 UT-7b, inhibited lidocaine 3-hydroxylation in liver microsomes from untreated male rats, but had little effect on lidocaine N-deethylation. These findings suggested that lidocaine 3-hydroxylation in hepatic microsomes from untreated male rats was catalyzed by P-450 UT-7 and/or UT-7b.P-450 UT-7 not containing 29 k-protein was obtained as the non-absorbed fraction from hydroxylapatite HPLC. The activities of debrisoquine 4-hydroxylation as well as lidocaine 3-hydroxylation and N-deethylation in a reconstituted system with P-450 UT-7 without 29 k-protein were one-fifth of those of P-450 UT-7 containing 29 k-protein at the same substrate concentration. These findings suggested that the 29 k-protein was essential to express the maximal metabolic activities. However, the lidocaine metabolic activity in a reconstituted system with P-450 UT-7 containing 29 k-protein and in hepatic microsomes were not inhibited by 29 k-protein antibody.

Identification of CYP2C23 expressed in rat kidney as an arachidonic acid epoxygenase

A cDNA was isolated from a rat kidney cDNA library using mixed probes of CYP (cytochrome P450) 2C6, 2C7, 2C8, 2C9 and 2C18 cDNAs. The 3'-terminal and 5'-terminal regions of the cDNA were sequenced and were identical with those of cytochrome P450 2C23 (CYP2C23) except for a one-base deletion and a one-base addition in coding region. These changes caused a frame shift and changed the deduced amino acid sequence relative to the previously published sequence. This cDNA was expressed using a baculovirus expression system, and the resultant P450 had a lambda max of 450 nm when reduced and complexed with carbon monoxide. Specific content of the expressed P450 ranged from 0.27 to 0.43 nmol/mg of cell lysate protein. Arachidonic acid metabolism catalyzed by expressed CYP2C23 indicated that CYP2C23 efficiently produced epoxyeicosatrienoic acids (EETs). These EETs were characterized further by gas-liquid chromatography/negative ion chemical ionization mass spectrometry (GC/NCIMS) and were found to include 8,9-EET, 11,12-EET and 14,15-EET in a ratio of 1:2:1. No 5,6-EET was detected. A low rate of lauric acid hydroxylation at the (omega-1)-position was found, but the enzyme was unable to metabolize prostaglandin E1. These studies suggest that CYP2C23 is responsible, in part, for the production of EETs in rat kidney.

[Some problems of TS measurement after administration of fluoropyrimidines in colorectal cancer. Kinki Cooperative Study Group of Chemotherapy for Colorectal Carcinoma]

A joint multicenter comparative study of carmofur (HCFU) alone or HCFU+dipyridamole (DP) concurrent administration was conducted by the Kinki Colorectal Cancer Chemotherapy Society. In this study, the drugs were administered five days prior to surgery, and thymidylate synthetase (TS) inhibition rate at the primary lesion of colorectal cancer was determined. In addition, the effect of time after resection of the primary lesion before specimen cooling on the TS inhibition rate was investigated. The subjects were 87 registered patients who received colorectal cancer surgery during 4 months from October 1991 to January 1992. The time before postsurgical cooling was divided into four group; within 10 min (n = 67), 11-20 min (n = 8), 21-30 min (n = 7), and 31 min or longer (n = 5). The TS inhibition rates (mean +/- SD) were 0.45 +/- 0.22, 0.38 +/- 0.19, 0.30 +/- 0.21, and 0.04 +/- 0.05 respectively. The longer the time after resection of the primary lesion before specimen cooling, the more TS inhibition rate decreased. When the time before specimen cooling exceeds 30 min, the major part of TS combined with FdUMP exists in a free state. Therefore, it was considered not suitable as the material for the measurement.

Mitochondrial NADPH-linked aquacobalamin reductase is distinct from the NADPH-linked enzyme from microsomal membranes in rat liver

Mitochondrial NADPH-linked aquacobalamin reductase was purified and characterized to clarify its enzymatic properties. The enzyme was purified about 360-fold over rat liver mitochondrial membranes in a yield of 7.5%. The purified enzyme was homogenous in SDS-PAGE. The molecular mass (M(r)) of the enzyme was calculated to be 65 kDa by SDS-PAGE and by Toyopearl HW55 gel filtration, indicating that the enzyme is a monomeric polypeptide with M(r) of 65 kDa. The enzyme was a flavoprotein containing 1 mol of FAD and FMN per mole of the enzyme. The enzyme was specific for NADPH as electron donor and had the ability to reduce cytochrome c (15.4 mumol.min-1 x mg protein-1), potassium ferricyanide (4.9 mumol.min-1 x mg protein-1) and 2,6-dichlorophenolindophenol (16.8 mumol.min-1.mg protein-1) as well as aquacobalamin (6.4 mumol.min-1 x mg protein-1). Although the enzyme immunoreacted with an antibody against NADPH-cytochrome P-450 reductase, which had the activity of the NADPH-linked aquacobalamin reductase in rat liver microsomes, the mitochondrial enzyme and the microsomal enzyme had different enzymological properties.

Surgical resection of potentially curable pancreatic cancer with improved preservation of endocrine function--further evaluation of intraoperative cytodiagnosis

Very early detection of pancreas cancer is most desirable, since it permits less invasive surgery which has a correspondingly greater chance of success. The present study investigated both surgical outcome and postsurgical quality of life in 8 patients whose occult neoplasms were successfully treated. In all 8 patients, cytology of the pancreatic secretion obtained during endoscopic retrograde pancreatography (ERP) was positive, although no pancreatic tumor was detected by ERP, other examinations or intraoperative inspection. In these 8 patients, our method of intraoperative cytodiagnosis to locate occult neoplasms of the pancreas (Surgery 1992; 111: 294-300) was used (1). Using this method of cytodiagnosis, we were able to avoid total pancreatectomy in 6 patients (75%; 3 pancreatoduodenectomies and 3 caudal pancreatectomies), but not in the other 2 patients. Histopathological study of the resected specimens indicated that the extent of pancreatic resection was quite appropriate in all 8 patients. There were 6 minimally invasive carcinomas, one carcinoma in situ and one borderline lesion. Neither nodal involvement nor severe invasion was found on microscopic inspection, and all have been disease-free for 23 +/- 13 months after surgery. In the 6 patients with partial pancreatectomies, both postoperative quality of life and general health were good, with no insulin-dependent diabetes developing. Thus, our cytology-guided surgical technique is very useful not only for locating occult and potentially curable neoplasms, but also for avoiding blind resection of the entire pancreas, permitting better preservation of pancreatic endocrine function.

[Changes of serum interleukin 6 (IL6) and acute phase protein after hepatectomy in patients with chronic liver disease]

We examined the changes in serum levels of interleukin 6 (s-IL6) and acute phase protein (APP) during perioperative periods in patients with or without chronic liver disease (CLD) who underwent hepatectomy or other surgeries. The elevation of s-IL6 on the first postoperative day was only correlated with preoperative values of indocyanine green retention test (ICG-R15) (r = 0.56, p < 0.01), and not concerned with any operative factors. We divided the patients into the following three groups; the patients with CLD undergoing hepatectomy (n = 21, group A), the patients without CLD undergoing hepatectomy (n = 7, group B), and the patients without CLD undergoing surgeries other than hepatectomy (n = 7, group C). The values of s-IL6 on preoperative day, 1st, 4th, and 7th days after surgery in group A were significantly higher than the corresponding values in group C (p < 0.05). Among the hepatectomy groups, the serum levels of APP on the 4th day after surgery were significantly higher than those on preoperative day. We concluded that the changes in s-IL6 after hepatectomy were strongly concerned with preoperative liver function, especially with values of ICG-R15. However, it seemed that the induction of APP was negatively correlated with the preoperative liver function.

Clinicopathological features and prognostic significance of nucleoside diphosphate kinase/nm23 gene product in human pancreatic exocrine neoplasms

Expression levels of nucleoside diphosphate (NDP) kinase/nm23 gene product in the surgically resected 59 human pancreatic exocrine neoplasms were examined immunohistochemically using antiNDP kinase antibody. Immunoreactivity for NDP kinase varied from one tumor to the other. Out of the 47 invasive pancreatic duct cell carcinomas examined, 31 (66%) tumors showed strong immunoreactivity for NDP kinase, whereas ten (83%) of 12 benign or less invasive tumors (in situ adenocarcinoma and mucin-producing tumor) showed negative or weak immunoreactivity (p < 0.01; Chi-square test). Overall survival of invasive pancreatic duct cell carcinomas with strong immunoreactivity for NDP kinase was poorer than those with negative or weak immunoreactivity (p < 0.03; generalized Wilcoxon test). Strong immunoreactivity for NDP kinase was associated with the type of histological differentiation, the presence of lymph node metastases (p < 0.05, respectively; Chi-square test), and the number of argyrophilic nucleolar organizer regions (p < 0.01; Student's t-test). These results suggest that NDP kinase/nm23 gene product expression was positively associated with tumor aggressiveness and poor survival of patients in human pancreatic exocrine neoplasms. They also suggest that NDP kinase expression is related to cell proliferation activity represented by the number of argyrophilic nucleolar organizer regions. Therefore, examining the level of NDP kinase/nm23 gene product could serve as a marker for malignant potentiality of pancreatic exocrine neoplasms.

Cytochrome P450 isozymes catalyzing the hepatic microsomal oxidation of 9-anthraldehyde to 9-anthracene carboxylic acid in adult male rats

Microsomal aldehyde oxygenase (MALDO) activity for 9-anthraldehyde (9-AA) was significantly higher in the male than in the female adult rat liver. 9-AA MALDO activity was also significantly enhanced by pretreatment with dexamethasone and phenobarbital, whereas it was not significantly changed by 3-methylcholanthrene or acetone. Several cytochrome P450 isozymes purified from rat hepatic microsomes were able to catalyze the oxidation of 9-AA to 9-anthracene carboxylic acid (9-ACA) in the presence of NADPH, NADPH-cytochrome P450 reductase and dilauroylphosphatidylcholine. Under the ordinary conditions of the reconstituted system, the catalytic activities (nmol/min/nmol P450) of cytochrome P450s, 2A1, 2B2, 2C6, 2C11 and 3A2 were 1.53 (1.37 in the presence of cytochrome b5), 1.20 (2.06), 4.87 (7.75), 18.0 (21.6) and 0.90 (1.17), respectively. Cytochrome P450 2C11 (CYP 2C11) showed the highest catalytic activity of the cytochromes examined. In the reconstituted system using the lipids extracted from microsomes, CYP 3A2 more effectively catalyzed the oxidation of 9-AA to 9-ACA, and its catalytic activity (nmol/min/nmol P450) was 3.33 or 6.61 in the absence or presence of cytochrome b5, respectively. The antibody against CYP 2C11 inhibited by 90% the hepatic microsomal oxidation of 9-AA MALDO activity in adult male rats, but the activity was not inhibited by antibody against CYP 3A2. These results show that the individual forms of cytochrome P450 have a catalytic activity for the oxidation of 9-AA to 9-ACA, and that CYP 2C11 is the major constitutive catalyst of 9-AA MALDO activity in untreated adult male rat liver.

Purification and characterization of a form of P450 from horse liver microsomes

A form of P450 [termed P450(h-1)] was purified from the liver microsomes of a male horse to electrophoretic homogeneity. The specific content of the final P450(h-1) preparation was 14.8 nmol/mg of protein and the recovery was 0.38% of the microsomal P450. The apparent molecular weight of P450(h-1) was 52,000 Da. The absorption spectra of P450(h-1) indicated that P450(h-1) was a low- and high-spin mixed type P450 in the oxidized form. The reconstituted system containing P450(h-1) could catalyze benzphetamine N-demethylation, 7-ethoxycoumarin O-deethylation, and testosterone 16 alpha-hydroxylation. In the horse hepatic microsomes, aniline p-hydroxylation and testosterone 6 beta-hydroxylation, in addition to the above reactions, were detected. The N-terminal amino acid sequence of P450(h-1) was highly homologous to that of rat P450 2C11. Western blot analysis using anti-P450(h-1) antibody revealed that this antibody most strongly recognized P450 2C13 among ten rat P450s belonging to eight different subfamilies involved in hepatic drug metabolism. This anti-P450(h-1) antibody inhibited the testosterone 16 alpha-hydroxylase activity in horse liver microsomes. These results suggest that P450(h-1) belongs to the P450 2C subfamily and contributes to the testosterone 16 alpha-hydroxylation in horse liver microsomes.

[Survey for primary tumor site in patients with initial clinical presentation of bone metastasis]

Among the patients who were examined with bone scintigraphy between April 1985 and March 1991, there were 27 patients whose initial clinical manifestation was bone metastasis and who were surveyed for the primary tumor site. The primary tumor site could be identified in 20 patients (74%), consisting of 9 patients with lung cancer, 3 with prostate cancer, 3 with hepatoma, 2 with renal cancer, and one each with thyroid cancer, adrenal cancer, and pleural malignant mesothelioma. In 17 of the 20 patients, the primary site had been detected within two months after presentation. Examinations which were helpful in identifying the primary site included chest radiography, sputum cytology, abdominal sonography, serum prostatic acid phosphatase level and pathologic examination of biopsy specimens. 99mTc-PMT scintigraphy was useful in the diagnosis of the hepatoma when accumulation was observed at the metastatic sites. In 2 patients, lung cancer had been recognized using follow-up chest radiography 3 and 6 months after presentation, respectively. One patient was diagnosed at autopsy as having adrenal cancer. In 7 patients the primary site remains unknown. Histology examination of the biopsy specimen performed in 6 of these patients revealed 4 to be adenocarcinoma and 2 undifferentiated carcinoma. The average survival period of the 17 patients who died was 9.5 months. Four patients are alive, and the outcome in the remaining 6 could not be determined.

Clonal analysis of fibroadenoma and phyllodes tumor of the breast

Clonality of fibroadenoma and phyllodes tumor of the breast was analyzed by means of the polymerase chain reaction using small DNA samples prepared from cryostat sections. The method of clonal analysis was based on restriction fragment length polymorphism of X-chromosome-linked phosphoglycerokinase gene and on differential methylation of the gene. Specimens from 10 fibroadenomas and 5 phyllodes tumors heterozygous for the BstXI polymorphism of PGK gene were subjected to clonal analysis. It was found that fibroadenoma was polyclonal, but phyllodes tumor was made up of both monoclonal and polyclonal cell components. Since these tumors contained both epithelial and stromal components, clonality of each component was analyzed separately. Analysis of clonality of each cell component showed that both the epithelial and stromal cells were polyclonal in fibroadenoma and that the epithelial cells were polyclonal, but the stromal cells were monoclonal in phyllodes tumor. When DNA samples were prepared from widely separated sites of phyllodes tumors, every sample was found to contain a monoclonal stromal cell component. These results demonstrate that fibroadenoma is a hyperplastic lesion rather than a neoplasm, and that phyllodes tumor is a neoplasm of the stromal cells.

Changes in amounts of cytochrome P450 isozymes and levels of catalytic activities in hepatic and renal microsomes of rats with streptozocin-induced diabetes

Hepatic microsomal cytochrome P450s, which are involved in the metabolism of drugs, hormones, prostaglandins and fatty acids, change when animals develop diabetes. We studied changes in cytochrome P450 isozymes in both hepatic and renal microsomes of rats with diabetes caused by streptozocin, and compared the results with changes in catalytic activities in the microsomes. In hepatic microsomes of diabetic rats, the amount of cytochrome P450 2E1, an acetone-inducible isozyme, was two and a half times that of control rats, and that of P450 4A2, a major renal isozyme, was three times that in the controls. The amounts of cytochrome P450s 2A1, 2C6, 2C7, 3A2 and 4A3 increased in hepatic microsomes of diabetic rats, and P450 2C11 decreased. Treatment with insulin restored these to the levels in the controls. The catalytic activities of aniline hydroxylation, 7-ethoxycoumarin O-dealkylation, testosterone 2 beta, 6 beta, 7 alpha, and 16 beta-hydroxylation, and omega-, (omega-1)-hydroxylation of lauric acid were high in the hepatic microsomes of diabetic rats, and testosterone 2 alpha and 16 alpha-hydroxylation activities were low. In renal microsomes of diabetic rats, cytochrome P450s 2E1, 4A2 and K-4 were induced, and omega- and (omega-1)-hydroxylation activities were high. These changes were reversed by insulin treatment. The induction and suppression of cytochrome P450 isozymes in diabetic rats were consistent with the changes in the catalytic activities. In both hepatic and renal microsomes, P450s 2E1 and 4A2 were induced, altered metabolism of ketones and fatty acids in diabetes may contribute to these changes.

Increased expression of sialyl Lewisx antigen correlates with poor survival in patients with colorectal carcinoma: clinicopathological and immunohistochemical study

We have previously shown that sialyl Lewisx antigen (sLex) (NeuAc alpha 2-3Gal beta 1-4(Fuc alpha 1-3)GlcNAC-R) has an important functional role in defining the invasion and metastasis of human colorectal carcinoma. The results were derived from the clinical specimens obtained at surgery or experimental metastasis of human colon carcinoma variant expressing different levels of sLex in nude mice. In the present study, we immunohistochemically examined 132 human colorectal carcinomas for the expression of sLex to investigate whether this antigen expression could serve as a prognostic parameter. The tumors were divided into two groups: sLex positive and sLex negative. The incidence of sLex positive was correlated with the depth of tumor invasion, the presence of the lymph node metastasis, lymphatic invasion, and the disease stage. The difference was statistically significant (P = 0.0026; P = 0.0002; P = 0.003; P = 0.0013; respectively). Based on the data on 114 patients who underwent curative resections, incidence of the disease recurrence was assessed. The sLex-positive patients had higher incidence of recurrence in distant organs, especially in the liver, than that of the sLex-negative patients. The 5-year disease free survival rates of sLex-positive and -negative patients were 57.7 and 89.1%, respectively (P = 0.0002). The difference of 5-year overall survival rates between the two were also significant (sLex positive, 58.3%; sLex negative, 93.0%: P < 0.0001). By Cox multivariate analysis, sLex expression levels remained the best discriminant of disease-free survival (P = 0.035) and overall survival (P = 0.0081). These results suggest that increased expression of sLex is correlated with the extent of malignancy and high incidence of recurrence and consequently with survival of colorectal carcinoma patients. Thus sLex may prove to be a potent marker of recurrence in colorectal carcinoma patients.

[Evaluation of intra-arterial infusion chemotherapy and radical pancreatectomy in patients with locally advanced pancreatic cancer]

This is a retrospective study to evaluate arterial infusion chemotherapy and resection for locally advanced pancreatic cancer involving retro-peritoneal organs or large vessels such as superior mesenteric artery or celiac trunks. Intra-arterial chemotherapy was performed for 19 patients, and 15 underwent pancreatectomy. Patients in the intra-arterial chemotherapy group could live 11 months out of the hospital, against 4 months in the resected cases (p < 0.05). The period of over 2nd degree in performance status was 11 months in the arterial chemotherapy group and 3 months in resected groups (p < 0.05). The survival rates were 53, 18 and 9% at 1, 2 and 3 years in the patients with arterial chemotherapy, respectively, against 22, 15 and 15% in the resected patients (p < 0.05). These results suggested that intra-arterial chemotherapy was significantly effective in prolonging the survival period with a better quality of life.

Magnetic resonance imaging-histologic correlation of small hepatocellular carcinomas adenomatous hyperplasias

RATIONALE AND OBJECTIVES

Hepatocellular carcinomas (HCCs) usually consist of components of different histologic grade. Using surgically resected specimens, the authors obtained high-resolution magnetic resonance (MR) images and studied the relationship between histologic grade of HCCs and MR signal intensity.

METHOD

In vitro MRI was performed on 15 small (less than 20-mm diameter) HCCs and 2 patients with adenomatous hyperplasia (AH) within 1 hour of surgical resection. In these 17 lesions, 24 macroscopic nodular components corresponding to MR images were recognized pathologically. The difference in MR signal intensity was examined by using tumor/phantom (T/P) signal-intensity ratio. In addition, the correlations between signal intensity on MRI and histologic criteria for grading HCC were studied.

RESULTS

On T2-weighted images, grade II HCCs had significantly greater T/P values than grade I HCCs (P < .01). There is the correlation (r = .88, P < .001) between nucleocytoplasmic (N/C) ratio and signal intensity of small HCCs and AHs on T2-weighted images.

CONCLUSION

The N/C ratio is an important factor relating the signal intensity to the histologic grade of these lesions on T2-weighted images.

Palliative surgical treatment for recurrent and non-resectable hepatocellular carcinoma

Of 275 patients who had a radical hepatic resection for HCC, 143 (52%) experienced recurrences. Of these 143 patients, the liver was the site of first recurrence in 130 patients (91%). The first form of therapy for recurrent patients was transarterial chemoembolization (TACE) in 82 (74%), hepatic resection in 15 (14%) and percutaneous ethanol injection in 6 (5%) of the 111 patients who received regional therapy. Post-recurrent survival rates of TACE and hepatic resection were 37%, 77% at 3 years and 17%, 77% at 5 years, respectively. Wrapping therapy was performed in seven patients, two of whom had received repeat TACE for intrahepatic recurrence; the remaining 5 were unresectable cases. After wrapping therapy, the area of previous collateral feeders was be supplied by the hepatic artery. The high level of AFP decreased dramatically. This procedure resulted in a complete response in 2 patients, a partial response in 3 and no change in 2. Overall survival was 4-54 months, and the median survival was 18 months. Two patients are still alive, 18 and 20 months after the procedure.

["Partial wrapping therapy" for recurrent hepatocellular carcinoma by transthoracic route]

Two patients with recurrent hepatocellular carcinoma close to the diaphragma, underwent TAE following decollateralization using silicone rubber sheeting with thoracotomy. The patients suffered from severe liver cirrhosis. Laparotomy was not carried out for the preservation of hepatic function. After wrapping therapy, serum AFP level was reduced to almost the normal range in one case, but in another case to half because of bilateral lung metastasis. The maximum serum level of postoperative serum total bilirubin in these 2 cases was 2.0 mg/dl and 1.6 mg/dl, respectively. We think wrapping therapy with thoracotomy is readily applicable for patients with severe cirrhosis.

[Composite resection of sciatic nerve for local recurrence of rectal cancer]

Three patients with local recurrence of rectal cancer involving the sciatic nerve underwent radical pelvic exenteration combined with sciatic nerve resection. This surgical procedure resulted in complete relief of intolerable cancer pain in all patients. After the rehabilitation, all could walk unassisted by wearing only a below-the-knee leg brace. The first patient died 16 months postoperatively due to multiple liver metastasis, but no local recurrence was documented. The second patient is alive 13 months postoperatively with bone and liver metastasis and pelvic wall recurrence. The third patient is alive 7 months postoperatively with no evidence of disease. Composite resection of lateral sciatic nerve improved the quality of life in patients who had local recurrence of rectal cancer with sciatic nerve involvement.

[Significance of preoperative TAE as an adjuvant therapy for hepatocellular carcinoma]

In 304 patients with hepatocellular carcinoma who underwent hepatic resection, 162 patients received chemoembolization before surgery (group A) and the remaining 142 patients received no therapy before surgery (group B). The 5-year disease-free survival (DFS) of group A and B were 36% and 21%, respectively, and there were no significant differences between them. In the groups of patients with good liver function (Child A), or patients with solitary tumor, or patients with tumors more than 5 cm in size, DFSs of group A were significantly better than those of group B. The difference of DFS between group A and B was largest in the group of the patients with tumors more than 5 cm in size.

Down-regulation of transforming growth factor-alpha by tamoxifen in human breast cancer

BACKGROUND

The influence of tamoxifen treatment on transforming growth factor-alpha (TGF-alpha) levels in human breast cancer rarely has been studied in vivo.

METHODS

Postmenopausal patients with estrogen receptor (ER)-positive and progesterone receptor (PR)-positive primary breast cancer underwent two fine-needle aspiration biopsies (FNA) of the tumors. Between the two FNAs, 10 patients received no treatment (control group), and the other 10 patients received tamoxifen (20 mg/day) for 10 (8-12) days (TAM group). TGF-alpha levels in FNA samples were assayed by enzyme immunoassay.

RESULTS

No significant difference was found in TGF-alpha levels between the first and second FNA samples in the control group. On the other hand, in the TAM group, TGF-alpha levels in the second FNA samples (2.5 +/- 0.5; mean +/- SEM ng/mg.DNA) were significantly (P < 0.01) lower than those in the first (4.5 +/- 0.8). Studies on the influence of tamoxifen treatment on TGF-alpha levels in ER-negative and PR-negative breast cancer showed that TGF-alpha levels were not affected by tamoxifen treatment. Positivity of epidermal growth factor receptor (EGFR) was 60% in ER-negative and PR-negative breast cancer and 30% in ER-positive and PR-positive breast cancer.

CONCLUSIONS

Tamoxifen downregulates TGF-alpha levels in ER-positive and PR-positive breast cancers through ER. The significance of TGF-alpha as an autocrine growth factor appears to be more important in ER-negative and PR-negative breast cancer with high EGFR positivity than in ER-positive and PR-positive breast cancer with low EGFR positivity.

Changes in the amounts of cytochromes P450 in rat hepatic microsomes produced by cyclosporin A

1. The effect of cyclosporin A, an immunosuppressive drug, on the levels of individual cytochromes P450 of rat liver was studied by immunoblotting with specific antibodies. Changes in the metabolic activities of the microsomal enzymes were similarly studied. 2. Total P450 was decreased by treatment with cyclosporin A for 17 days. NADPH-P450 reductase activity was also decreased by treatment with cyclosporin A for 10 days and decreased further after 17 days. 3. Cytochromes 2B2 and 2C6 concentrations were decreased by treatment with cyclosporin A for 17 and 10 days, respectively. Administration of cyclosporin A for 17 days also decreased the levels of the male specific cytochromes 2C11 and 3A2, and consequently decreased testosterone 2 alpha-, 16 alpha-, 2 beta- and 6 beta-hydroxylation activities. Shorter periods (7 and 10 days) of cyclosporin A treatment decreased the level of cytochrome 3A2, which metabolizes cyclosporin A. In contrast, the level of cytochrome 2C13 was unchanged.

Delayed washout of intratumor blood flow is associated with good response to intraarterial chemoembolization for liver metastasis of colorectal cancer

BACKGROUND

We studied stagnation of the blood in hepatic metastatic lesions of colorectal cancer.

METHODS

Twenty-two hepatic tumors in 11 patients with liver metastases of colorectal cancers were investigated in this study. With a catheter inserted into the roots of the proper hepatic artery, 5 to 10 mCi 133Xe was injected. The half-time (t1/2) was calculated for the tumor region based on the washout curve by the compartmental method and expressed as the intratumor retention time of the blood.

RESULTS

Transcatheter arterial chemoembolization with iodized oil (Lipiodol) and cisplatin was effective in eight (50%) of 16 tumors that were hypervascular but in only one (17%) of six tumors that were hypovascular (p < 0.05). Regardless of the hypervascular tumor, transcatheter arterial chemoembolization was not effective in tumors that had shown a t1/2 of less than 80 seconds. Seven of eight good-responding lesions that were hypervascular and had a long t1/2 (187 +/- 74.6 seconds) revealed characteristic fireworks-shaped accumulation of Lipiodol.

CONCLUSIONS

Transarterial infusion chemotherapy for liver metastasis of colorectal cancer was considered effective for hypervascular hepatic tumors with a long t1/2.

Nicotine metabolism by rat hepatic cytochrome P450s

Many kinds of cytochrome P450s were purified from rat hepatic microsomes, and their role in the metabolization of nicotine in a reconstituted system examined. Of four phenobarbital-inducible P450s, P450 2B1 had the highest nicotine oxidation activity and P450 2B2 showed a low rate of nicotine oxidation, whereas P450 2C6 and 3A2 had no detectable activity toward nicotine. Among eleven other purified cytochrome P450s tested, P450 2C11 had high nicotine oxidation activity and P450 1A2 and 2D1 showed low catalytic activity toward nicotine. The other cytochrome P450s, P450 1A1, 2A1, 2A2, 2C7, 2C12, 2C13, 2E1 and 4A1, had no detectable nicotine oxidation activity. Based on these results, participation of cytochrome P450s in nicotine metabolism in human and animal livers is discussed.

Inhibitory effect of a somatostatin analogue (SMS 201-995) on the growth of androgen-dependent mouse mammary tumor (Shionogi carcinoma 115)

The influence of a somatostatin analogue, SMS 201-995 (SMS), on the growth of an androgen-dependent mouse mammary tumor, Shionogi carcinoma 115 (SC115), was studied. Treatment of SC115 tumor-transplanted male mice with s.c. injections of SMS (0.04, 0.2, 1, and 5 micrograms twice a day) resulted in a dose-dependent inhibition of tumor growth. The growth-inhibitory effect of SMS reached its peak at a dose of 1 microgram twice a day. SMS was found not to elicit its growth-inhibitory effect through lowering plasma testosterone levels or down-regulating androgen receptor of SC115 tumors. Since specific binding sites for somatostatin were not observed in the membrane fractions of SC115 tumors and SMS did not inhibit the proliferation of primarily cultured SC115 tumor cells, a direct inhibitory mechanism of SMS on SC115 tumors was unlikely to be operative. Since SMS is a very potent inhibitor of growth hormone (GH) secretion, it was speculated that SMS might inhibit the growth of SC115 tumors indirectly through down-regulation of plasma GH levels. This possibility was evaluated by studying the influence of GH replacement on the growth of SC115 tumors grown in SMS-treated mice. GH replacement was done both in a male secretory pattern (intermittent injection, human GH 500 micrograms/kg twice a day) and in a female secretory pattern (continuous infusion, 1000 micrograms/kg/day). Intermittent injections of GH fully restored the growth of SC115 tumors in the SMS-treated mice to that in the normal controls but continuous infusion of GH was without effect. These results suggest that SMS inhibits the growth of SC115 tumors through suppression of GH secretion, and that the mode of GH administration is an important determinant of its action on SC115 tumor growth.

Level of serum gastrin as a predictor of liver metastasis from colorectal cancer

There have been no reports on the relationship between serum gastrin level and liver metastasis in human colorectal cancer. One hundred forty patients who underwent surgery for colorectal cancer (T2 or more) were enrolled in this study. Fasting serum gastrin level was determined prior to the surgery. Incidence of liver metastasis was significantly (P < 0.01) higher in patients with a serum gastrin level of > or = 150 pg/ml (37 percent; 14/38) than in those with a serum gastrin level of < 150 pg/ml (12 percent; 12/102). As for the tumors with venous invasion, liver metastasis was detected in 11 of 55 patients (20 percent) with a serum gastrin level of < 150 pg/ml; however, it was detected in 11 of 19 patients (58 percent) with a serum gastrin level of > or = 150 pg/ml (P < 0.01). These results suggest that serum gastrin serves as a useful predictor of liver metastasis from colorectal cancer and that the predictability of liver metastasis can be improved when both serum gastrin level and venous invasion are considered.

Suppression of liver microsomal drug-metabolizing enzyme activities in adult female rats pretreated with cannabidiol

The suppression by cannabidiol (CBD) of the liver microsomal drug-metabolizing enzyme activities in female rats was demonstrated and its mechanism was examined. Pretreatment of rats with CBD (10 mg/kg, i.p.) caused temporary decreases in contents of cytochrome P450 (P450) and b5 and NADPH-cytochrome c (P450) reductase activity compared with values from the vehicle control group. p-Nitroanisole O-demethylase, aniline hydroxylase, d-benzphetamine N-demethylase and delta 9-tetrahydrocannabinol 11-hydroxylase were also decreased by the CBD pretreatment. The latter two activities took a longer time to return to control levels than the former two. However, the CBD pretreatment, which reduced the protein level of P450 UT-2 (CYP2C11) in adult male rats, did not decrease the protein level of P450 F-1 (CYP2C6) or F-2 (CYP2C12) in liver microsomes from female rats. These results suggest that the mechanisms by which CBD suppresses liver microsomal drug-metabolizing enzyme activities are different in male and female rats.

Hookwire localizer as an aid for ultrasonic detection of small liver nodules

We applied a V-shaped localizer and evaluated its clinical usefulness in nine patients with small hepatic nodules less than 2 cm in diameter. A small hepatic nodule was punctured with a 21-gauge localization needle under ultrasonic guidance, and the V-shaped localizer was pushed into the nodule with a wire. The localizer could be observed as a strong echo line by ultrasonography and as a high-density bar by computed tomography (CT). By this method, it was possible to precisely localize the nodule. Intraoperative ultrasonography became less time-consuming, and resection of the nodules could be confirmed with low-kilovoltage radiography.

Immunoelectron microscopic localization of basic FGF in neuroglias and neurons of the trigeminal mesencephalic and motor nuclei

Discrepancies between previous light microscopic studies on the localization of basic fibroblast growth factor (bFGF) in neuroglias and neurons of the normal rat brain prompted us to investigate, by electron microscopy, the subcellular localization of bFGF-like immunoreactivity in neuroglias and neurons of the trigeminal motor and mesencephalic nuclei. Immunostaining intensity differed from astrocyte to astrocyte; in astrocytes labeled heavily with bFGF antiserum, the precise subcellular location of immunoreaction deposits was difficult to determine, whereas mildly labeled astrocytes contained reaction products in subcellular regions apart from gliofilaments, mitochondria and Golgi apparatus. A comparison of immunostained sections with negative control ones at the light and electron microscopic levels revealed that astrocyte nuclei occasionally showed bFGF immunoreactivity. Immunoreactive astrocyte processes were also found in close apposition to blood vessels. bFGF was detected mainly in intracellular structures close to free ribosomes and the endoplasmic reticulum of immunoreactive oligodendrocytes and neurons; microglias rarely showed immunostaining. The nuclei of the cells with bFGF contained immunoreaction deposits of varying intensity, mainly in the euchromatin and rarely in the heterochromatin. Occasionally, bFGF of neuroglial origin accumulated in the vicinity of the interface between neurons and neuroglias. The extracellular matrix was not immunoreactive in any of the areas examined. These findings suggest that certain populations of astrocytes and oligodendrocytes as well as neurons in the normal brain contain bFGF-like substances.

Expression of nucleoside diphosphate kinase/nm23 gene product in human pancreatic cancer: an association with lymph node metastasis and tumor invasion

The expression of nucleoside diphosphate (NDP) kinase/nm23 has been reported to be inversely related to metastasizing potential of experimental cells and human breast cancer. In the present study, levels of NDP kinase/nm23 gene product in curatively resected human pancreatic adenocarcinomas were examined immunohistochemically using anti-NDP kinase antibody. Immunoreactivity for NDP kinase varied between tumors. Of 31 pancreatic tumors examined, 17 (55%; positive staining group) showed strong immunoreactivity for the NDP kinase, while 14 (45%; negative staining group) showed low or no immunoreactivity. Positive staining was associated with higher incidence of lymph node metastasis (13/17; 77%) and perineural invasion (13/17; 77%) than negative staining (5/14, 36%, P < 0.03; 4/14, 29%, P < 0.01, respectively). Positive staining was also associated with shorter overall survival and relapse-free survival than negative staining (P < 0.01, P < 0.01, respectively). No significant difference in age, sex, size, location of tumor, serum carcinoembryonic antigen (CEA) level, or histological type was found between the two groups. These results showed that, in contrast to the reports on breast cancer, NDP kinase/nm23 expression in human pancreatic cancer is positively associated with lymph node metastasis or perineural invasion and with poor prognosis. These, together with other previous reports, suggest that NDP kinase may play an important role in cancer progression or aggressiveness by altering its expression in a tissue-specific manner.

Cytochrome P-450-butyl peroxide complex detected by ESR

ESR measurements were performed for the reaction systems composed of t- or n-butylhydroperoxide and cytochrome P-450 (UT-2), purified from rat liver microsomes. On addition of n-butylhydroperoxide to the P-450 at pH 7.4, ESR signal due to a ferric low-spin species (g1 = 2.29, g2 = 2.24 and g3 = 1.96) was recorded. The observed g-parameters agreed well with those of a model thiolate-heme-iron(III)-peroxide complex, Fe(III)TPP(-S-TGE) (-OO-t-butyl) (g1 = 2.285, g2 = 2.198 and g3 = 1.959). In terms of the g-parameters, the new P-450 complex was concluded to be a P-450-butyl peroxide adduct, in which a butyl peroxide anion ligates at the sixth position of heme iron(III).

Up-regulation of estrogen receptor by tamoxifen in human breast cancer

BACKGROUND

Influence of tamoxifen treatment on estrogen receptor (ER) and progesterone receptor (PR) levels in human breast cancer has not been fully elucidated in vivo. This problem was studied in 20 postmenopausal patients with ER-positive and PR-positive primary breast cancer.

METHODS

Each patient underwent two fine-needle aspiration (FNA) biopsies. Between two FNA, 10 patients received no treatment (control group) and the other 10 patients were given tamoxifen (20 mg/day) for an average of 8 days (range, 6-10 days) (TAM group). Total ER and PR values (cytosolic plus nuclear fraction) in FNA samples were determined by enzyme immunoassay (EIA) for detecting ER and PR regardless of their occupancy with corresponding ligands.

RESULTS

In the control group, no significant difference was found in ER and PR values between the first and second FNA samples. In the TAM group, ER and PR values (mean +/- standard error of the mean [SEM] fmol/mg DNA) in the second FNA samples were 605 +/- 186 and 1130 +/- 344, respectively, and were significantly higher (P < 0.05) than ER and PR values in the first FNA samples, which were 312 +/- 74 and 639 +/- 159, respectively. ER and PR values increased by 201 +/- 27% and 163 +/- 23%, respectively, on an individual basis after tamoxifen treatment.

CONCLUSIONS

These results demonstrated that tamoxifen up-regulates ER and PR in human breast cancer.

Characterization of specific cytochrome P450 enzymes responsible for the metabolism of diazepam in hepatic microsomes of adult male rats

The role of several P450 enzymes in the metabolism of diazepam (DZ) has been investigated. Hepatic microsomes of adult male rats were pretreated with antisera raised against the P450s CYP3A2, 2B1, 2C6, 2C11, 2D1 and 2E1, and their influence on the subsequent metabolism of DZ was determined by simultaneously measuring the changes in the relative rates of formation of its metabolites. Several forms of P450 were found to be positively involved in DZ metabolism. Antisera of the "male-specific" P450 enzyme CYP2C11 partially inhibited both DZ N-demethylase and C3 hydroxylase activities (60%) which resulted in decreased formations of N-desmethyl-DZ (NDZ) and 3-hydroxy-DZ (3HDZ), respectively. In a reconstitution experiment with the purified enzyme, CYP2C11 predominantly catalysed the formation of NDZ from DZ. Antisera of a further male-specific P450 CYP3A2 strongly inhibited (95%) the C3 hydroxylase of DZ and thus 3HDZ formation. A corresponding reconstitution experiment with this same P450 enzyme gave 3HDZ as principal product. CYP2D1 antisera inhibited the aromatic hydroxylation of DZ (98%) and subsequent formation of 4'-hydroxy-DZ (4'HDZ). This enzyme was also observed to inhibit DZ N-demethylase activity (60%). A reconstitution experiment with pure CYP2D1 catalysed the formation of both 4'HDZ and NDZ.

MR features of various histological grades of small hepatocellular carcinoma

Twenty small hepatocellular carcinomas (HCCs) < 20 mm in diameter in 18 patients, detected by MRI, were surgically resected and histologically confirmed. Quantitative analysis of signal intensity on MR images was performed with 14 homogeneous lesions. In the five grade I HCCs, T1-weighted SE sequences provided significantly higher mean tumor-liver contrast and contrast-to-noise ratio (C/N) than T2-weighted SE sequences (p < 0.01). However, in the other nine HCCs (grade I + II or greater), T2-weighted SE sequences had significantly higher mean tumor-liver contrast and C/N values than T1-weighted SE sequences (p < 0.001). The T2-weighted SE sequences appear superior to T1-weighted SE sequences for grade I + II or greater HCC detection, whereas T1-weighted SE sequences are valuable in the detection of grade I HCCs.

Regio- and stereoselective propranolol metabolism by 15 forms of purified cytochromes P-450 from rat liver

Regio- and stereoselectivity of cytochrome P-450-mediated propranolol metabolism (4-, 5- and 7-hydroxylations and N-desisopropylation) was studied using 15 purified cytochrome P-450 species. With each purified cytochrome P-450 species, the regioselectivity was distinct and different between the two optical isomers used as substrates. The stereoselectivity was different depending on the position of propranolol to be metabolized. The regio- and stereoselectivity was altered when substrate concentration was altered, suggesting that the kinetics of the reactions are different depending on the positions of propranolol to be metabolized. Furthermore, the selectivity and its manner of alterations with substrate concentrations were different among all cytochrome P-450 species used. Propranolol, with its multiple metabolic pathways and optical isomers, is an extremely interesting substrate for characterization of cytochrome P-450 species.

Expression of cytochrome P450 in LEC rats during the development of hereditary hepatitis and hepatoma

The expression of 14 forms of cytochrome P450 in the liver as well as changes in the testosterone hydroxylation activities of hepatic microsomes were investigated during the development of hepatitis in Long-Evans Cinnamon (LEC) rats. P4501A1 and -1A2 (3-methylcholanthrene-inducible forms) and P4502B1 and -2B2 (phenobarbital-inducible forms) were barely detected in the hepatic microsomes of male and female LEC rats. In immature male rats, the levels of male-specific forms (P4502C11 and -2C13) were higher in LEC rats than in control Long-Evans Agouti (LEA) rats. P4502C11 appeared in female LEC rats from 4 to 16 weeks of age, reflecting that testosterone 2 alpha- and 16 alpha-hydroxylation activities were detected at significant levels in female LEC rats. In immature female rats, the level of P4502C12 (a major female-specific form) was higher in LEC rats than in LEA rats. The level of P4502C13 in male LEC rats and that of P4502C12 in female LEC rats decreased markedly with ageing or during the development of hepatitis. The level of P4503A2 (a male-predominant form) was especially high in immature male and female LEC rats, reflecting that both rats had high 2 beta- and 6 beta-hydroxylation activities toward testosterone. These sex-specific forms are regulated by androgens and by pituitary growth hormone. Thus, there may be abnormalities of the hypothalamo-pituitary-gonadal axis in LEC rats. Furthermore, P4503A2 efficiently activates aflatoxin B1, a potent hepatocarcinogen, and the increased levels of this form in LEC rats may be related to the onset of hepatitis or liver cancer.

Contribution of cytochrome P450s to MEOS (microsomal ethanol-oxidizing system): a specific and sensitive assay of MEOS activity by HPLC with fluorescence labeling

The contribution of cytochrome P450s to MEOS (microsomal ethanol-oxidizing system) in rat hepatic microsomes was studied with a modified assay method for MEOS activity. Acetaldehyde produced by MEOS was converted into the fluorescent derivative with cyclohexane-1,3-dione and analyzed by HPLC with a fluorescence detector. Acetaldehyde production by hepatic microsomes of rats treated with ethanol was higher by 75% than that by control rats. Ethanol oxidation activity of eight forms of P450 was investigated in a reconstituted system. CYP1A2 and CYP2E1 had high rates of acetaldehyde formation. The Km value of CYP2E1 for ethanol oxidation was 9.48 mM, similar to that of hepatic microsomes from rats treated with ethanol. The Km value of CYP1A2 was higher than that of CYP2E1, indicating the CYP1A2 with lower affinity for ethanol compared with CYP2E1. From the results of an inhibition study with antibodies, CYP2E1 was found to be a main contributor to MEOS induced by ethanol in rats, but CYP1A2 was considered to play an important role for MEOS when CYP2E1 was not induced. These results present the possibility that CYP1A2 and CYP2E1 contribute to MEOS activity.

Gastric remnant cancer as a metachronous multiple lesion

The pathological characteristics and natural history of 35 gastric remnant cancers after partial gastrectomy for a malignant condition and 16 gastric cancers after gastrectomy for benign conditions were compared. Gastric remnant cancer following malignant disease was characterized by a well defined rather than diffuse appearance (in 43 versus 12 per cent of gastric remnant cancers after benign conditions, P < 0.05), location away from the anastomosis (83 versus 25 per cent, P < 0.05) and a shorter interval after the first operation (5-14 versus > or = 20 years, P < 0.01). The 15- and 16-year survival rates appeared to be worse for gastric remnant cancer after malignant than after benign disease, but there was no statistically significant difference between the two groups in a generalized Wilcoxon test. In the former, direct invasion to adjacent organs was frequently observed. These findings suggest that gastric remnant cancer after gastrectomy for malignancy may be a metachronous multiple lesion, while that following benign disease may occur as a new cancer caused by the partial gastrectomy. To improve the survival of patients with cancer after gastrectomy for malignancy, a rational extended operation may be useful.

Clonal analysis of human breast cancer by means of the polymerase chain reaction

Clonality of human breast cancer was analyzed in small DNA samples prepared from cryostat sections, by means of the polymerase chain reaction (PCR). The method used for clonal analysis was based on restriction fragment length polymorphism of X-chromosome-linked phosphoglycerokinase (PGK) gene and on the differential methylation of the PGK gene due to random inactivation of one of two X-chromosomes by methylation in females. All the 20 breast cancer samples analyzed by the PCR-based method were monoclonal in origin and adjacent normal breast tissues were polyclonal. When DNA samples were prepared from widely separated sites of cancers, every sample was found to be monoclonal, always exhibiting inactivation of the same X-chromosome in each tumor. The study on sensitivity showed that the PCR-based method for clonal analysis can detect the presence of monoclonal cells against a polyclonal background when the monoclonal cell population is 50% or more. These results demonstrate that clonal analysis by means of PCR offers a good method for studying the clonality in small DNA samples prepared from cryostat sections of tumors. This method could be applied to distinguish between benign (polyclonal) and malignant (monoclonal) breast lesions.

Hormonal regulation of rat renal cytochrome P450s by androgen and the pituitary

The hormonal regulation of rat renal cytochrome P450s, P450 4A2 (K-5) and K-2, was investigated. The level of P450 4A2 in male rats was five times that in female rats and accounted for some 90% of total cytochrome P450, measured photometrically. Lauric acid omega- and (omega-1)-hydroxylation activities of renal microsomes of male rats were also higher than those of female rats. The sex differences in lauric acid hydroxylation activity seemed to arise from the differences in P450 4A2 concentrations, according to an immunochemical study. P450 K-2 was a female-dominant form in rat kidneys. The level of P450 K-2 in renal microsomes of male rats was one-tenth that of P450 4A2. Castration of male rats decreased the levels of P450 4A2 and treatment of castrated male rats with testosterone reversed the decrease. The castration of male rats decreased the lauric acid hydroxylation of the renal microsomes to the level of female rats. The administration of testosterone to castrated male rats reversed the decrease. Hypophysectomy of male rats decreased the level of P450 4A2 and the administration of growth hormone reversed the decrease when intermittent injections mimicking the male secretory pattern were given, although continuous administration mimicking the female secretory pattern did not. Castration of male rats did not affect the level of P450 K-2, but testosterone decreased its level. Hypophysectomy of male rats increased the level of P450 K-2 and growth hormone decreased its level in hypophysectomized rats. These results suggested that the expression of P450 4A2 was regulated by androgen or growth hormone and regulation of P450 4A2 was different from that of P450 K-2. To explore the regulation of renal cytochrome P450 further, testosterone was given to control (intact) or hypophysectomized adult female rats. P450 4A2 was induced in the kidneys of both control and hypophysectomized female rats to close to the level of male rats. Thus, P450 4A2 was directly regulated by testosterone as well as growth hormone, and the regulation of the male-dominant form in rat kidneys was different from that of the male-specific form in the rat liver, which is regulated mostly by growth hormone.

Heterozygous abnormal fibrinogen Osaka III with the replacement of gamma arginine-275 by histidine has an apparently higher molecular weight gamma-chain variant

Congenitally abnormal fibrinogen Osaka III with the replacement of gamma Arg-275 by His was found in a 38-year-old female with no bleeding or thrombotic tendency. Release of fibrinopeptide(s) by thrombin or reptilase was normal, but her thrombin or reptilase time in the absence of calcium was markedly prolonged and the polymerization of preformed fibrin monomer which was prepared by the treatment of fibrinogen with thrombin or reptilase was also markedly defective. Propositus' fibrinogen had normal crosslinking abilities of alpha- and gamma-chains. Analysis of fibrinogen chains on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) in the system of Laemmli only revealed the presence of abnormal gamma-chain with an apparently higher molecular weight, the presence of which was more clearly detected with SDS-PAGE of fibrin monomer obtained by thrombin treatment. Purified fragment D1 of fibrinogen Osaka III also seemed to contain an apparently higher molecular weight fragment D1 gamma remnant on Laemmli gels, which was digested faster than the normal control by plasmin in the presence of [ethylenebis(oxyethylenenitrilo)]tetraacetic acid (EGTA).

Mutagenic activation of aflatoxin B1 by pulmonary, renal, and hepatic cytochrome P450s from rats

The genotoxic and mutagenic activation of aflatoxin B1 (AFB1) by hepatic, renal, and pulmonary microsomes and purified cytochrome P450s was investigated in Salmonella typhimurium TA1535/pSK1002 cells in which an umu response shows DNA damage. The activity of the hepatic microsomes was greatest. Pulmonary microsomes had moderate activity and renal microsomes had low activity. P450 2C11, 2B1, 3A2, 4A2, 4B1, K-2, and K-4 were assayed in a reconstituted system with dilauroylphosphatidylcholine (DLPC). P450 2C11 (a major hepatic cytochrome P450 in male rats) had high activity. P450 2B1 (a major form as well as P450 4B1 in pulmonary microsomes) and K-2 (a minor form in renal microsomes) had moderate activity. P450 4A2 (a major form in renal microsomes), P450 K-4 (a renal form), and P450 4B1 had low activity. P450 3A2 did not have high activity in these conditions but it had high activity toward AFB1 in a modified reconstituted system with a lipid mixture and sodium cholate instead of DLPC only. The activities of other forms were not enhanced by the modification of reconstituted system. Anti-P450 2C11 or 3A2 antibodies inhibited the bioactivation of AFB1 by hepatic microsomes to 50%. These results suggest that the greater ability of hepatic microsomes as compared with pulmonary and renal microsomes to metabolize AFB1 to mutagenic products is a function of the relative proportions of the highly active cytochrome P450s, P450 2C11 and 3A2, in the liver.

[Evaluation of hepatic resection for stage IV hepatocellular carcinoma-comparison with arterial embolization therapy]

To evaluate the application of hepatic resection (HR) for patients with Stage IV hepatocellular carcinoma (HCC), we compared the back-ground factors and survivals after therapies between Stage IV HCC patients who underwent HR (n = 38) and those who received arterial embolization (n = 186, group C). Of the patients who had HR, 17 (45.1) had relative noncurative (RN) resection (group A) and the remaining 21 (55%) had absolute noncurative (AN) resection (group B). Back-ground factors in relation to liver function were significantly better in both A and B than in C. On the other hand, tumor-relating factors were better in A than in both B and C, and were worse in B than in C. Five-year survival rates of group A and group C were 37.1 and 13.1 respectively (A to C; p < 0.05) and there were no longer survivors than two years in group B. These results suggested that the group which had better back-ground factors gained the better prognosis. To compare the survivals in the patients having well back-ground factors who were dominant in group A, the patients whose clinical stage was I or the number of tumors was two or less were selected from each group. Among these selected patients, the survivals of group A were significantly better than those of the other groups.

Influence of coexisting cirrhosis on long-term prognosis after surgery in patients with hepatocellular carcinoma

BACKGROUND

As one of the reasons for the poor prognosis of patients with hepatocellular carcinoma (HCC) and cirrhosis, the influence of cirrhosis itself has not been clarified.

METHODS

We compared the postoperative long-term courses of patients with HCC and cirrhosis with the courses of patients with HCC and without cirrhosis to determine how the coexisting cirrhosis affected the prognosis after surgery. The patients with HCC who underwent curative hepatic resection consisted of 142 with associated histologically confirmed cirrhosis and 48 without cirrhosis.

RESULTS

The 5-, 7-, and 9-year survival rates were 44%, 32%, and 26%, respectively, in the patients with cirrhosis and 68%, 57%, and 57%, respectively, in the patients without cirrhosis. The prognosis of the group with cirrhosis was significantly worse than that of the group without cirrhosis. The main cause of death in both groups was cancer recurrence. The patients with cirrhosis had significantly lower recurrence-free survival rates at 3 years and later than had the patients without cirrhosis. A comparison of the background factors revealed no substantive disadvantages with regard to tumor-related and surgical factors in the patients with cirrhosis compared with the patients without cirrhosis. The recurrence-free survival rates after minor and major resection indicated fewer disadvantages of limited hepatectomy in the group with cirrhosis than in the group without cirrhosis. Moreover, the recurrence-free survival of the group with cirrhosis was shorter at less advanced stages than at more advanced stages when compared with that of the group without cirrhosis.

CONCLUSIONS

The higher carcinogenic potential in cirrhosis could be presumed to be the most likely reason for the poorer prognosis after surgery in the patients with HCC and cirrhosis.

[Regional therapy to prevent recurrence after surgery in hepatocellular carcinoma]

The significance of regional therapy to prevent recurrence after surgery for hepatocellular carcinoma (HCC) was evaluated. In 275 patients who underwent hepatic resection for HCC, 143 (52%) had recurrences. Post-recurrence survival of the patients with regional therapy for recurrent foci was significantly better than that of patients without such therapy. Five-year post-recurrence survival of the patients treated with second surgery (77%) was significantly better than that of patients treated with chemoembolization (17%). The difference in 5-year survival between the former and the latter seemed to be caused by the difference in the degree of tumor progression at the recurrence. A second hepatic resection was the treatment of choice for a solitary intrahepatic recurrent tumor. However, chemoembolization was recommended for two or more recurrent foci.

["Wrapping therapy" for advanced hepatic cancer with arterial and intraportal infusion chemotherapy]

A new treatment method to intercept collaterals using silicone rubber sheeting was used for 5 patients with advanced hepatic cancer. The therapy was carried out to prevent new collaterals. This procedure was followed by arterial chemoembolization, arterial infusion chemotherapy and intraportal infusion chemotherapy. The results were complete response in 2 patients, partial response in 2 patients, and no change in 1 patient. The overall survival time was 7-54 months after wrapping. Although a randomized control study is necessary to assess the true value of this method, the new therapy is considered worth using as an adjuvant treatment for advanced hepatic malignancies uncontrolled by arterial chemotherapy or chemoembolization.

[Evaluation of radiation therapy combined with intra-arterial infusion chemotherapy in patients with non-resectable pancreatic cancer]

This is a retrospective study to evaluate arterial infusion chemotherapy and radiotherapy for non-resectable pancreatic cancer without liver metastasis. Intra-arterial chemotherapy of the pancreas was performed for 17 patients, and 5 additionally received irradiation therapy. Five patients received radiation therapy alone. Both pain relief and tumor-reduction were more successful compared to the systemic chemotherapy group. In the locoregional treatment group, the patient survival rate was 50% at 1 year and 16% at 2 years. These rates were significantly higher than in the systemic chemotherapy group (p less than 0.01). Among the locoregional treatment groups, the median survival period was 7 months in radiation alone, 12 months in intra-arterial chemotherapy group, and 11 months in intra-arterial chemotherapy plus radiation group. These results suggested that locoregional treatment for pancreatic tumor is effective in increasing survival period and improving the quality of life.

Role of phospholipids in reconstituted cytochrome P450 3A form and mechanism of their activation of catalytic activity

Cytochrome P-450 coded for by the 3A gene family requires specific conditions in a reconstituted system, if its catalytic activity is to be efficient. We investigated the mechanism of activation of the catalytic activity of cytochrome P450 3A by phospholipids. Rat P450 PB-1 (3A2), human P450NF (3A4), and rabbit P450 3c (3A6) were used. They had low activity in a reconstituted system (system I) with dilauroylphosphatidylcholine (DLPC) but had high activity with a mixture of phospholipids (DLPC, dioleoylphosphatidylcholine, and phosphatidylserine) and sodium cholate (system II). P450 3A forms are cationic (having a high content of lysine residues) and needed the anionic phospholipid phosphatidylserine to have sufficient activity. Double-reciprocal plots of the metabolic rate of cytochrome P-450 versus the concentration of NADPH-cytochrome P-450 reductase showed that cytochrome P-450 and the reductase interacted more in system II than in system I. P450 PB-1 did not absorb at 450 nm in the presence of reductase, CO, DLPC, and NADPH, although other cytochrome P-450s absorbed at around 450 nm in such a mixture. However, P450 PB-1 was reduced in the presence of the phospholipid mixture and sodium cholate instead of DLPC. These results suggested that the stimulation of catalytic activity by phospholipids involved increased interaction between cytochrome P-450 and the reductase. Studies of proteolytic digestion and chemical cross-linking in systems I and II showed that a P450 3A form needed disaggregation of cytochrome P-450 and/or the reductase, not the formation of an aggregated complex necessary for the catalytic activity of other cytochrome P-450s.