[Symptoms, diagnosis and treatment of pancreaticobiliary maljunction associated with congenital cystic dilatation of bile duct]

The concept of congenital biliary dilatation (CBD) was established by Alonso-Lej whose classification has been widely accepted and become a standard. Todani, Komi and several investigators then added additional subclassifications and/or made a proposal of new classification. The trias, abdominal pain, abdominal mass and jaundice, had been characteristically found in these cases, but recently asymptomatic cases are often found. Many reports have shown that the cases with cystic dilation of the biliary duct frequently associated with biliary carcinoma and pancreaticobiliary maljunction (PBM), an anomalous union of pancreatic duct with biliary tree since the Rabbit's first report. Whereas extracorporeal ultrasound and CT scan are minimally invasive diagnostic procedures for these cases, a direct cholangiography, ERCP and PTC are the diagnostic procedures that make a definite diagnosis for the appropriate treatment. Recently, endoscopic ultrasound (EUS), helical CT and magnetic resonance cholangiopan-creatography (MRCP) have drawn an attention since these methods are less invasive than those ever being used. In particular, MRCP will be suitable for the screening of preoperative examination. Whereas cystoduodenostomy used to be performed in the past for these cases, the resection of dilatted bule duct along with the diversion of bile from pancreatic juice should be performed to prevent biliary carcinoma. Cholecystectomy along with the resection of bile duct and the biliary diversion from pancreatic juice should also be performed for cases of PBM without CBD because mutagenicity of bile mixed with pancreatic juice and K-ras point mutation in noncancerous bile duct epithelium in cases of PBM without CBD were demonstrated.

K-ras point mutations in cancerous and noncancerous biliary epithelium in patients with pancreaticobiliary maljunction

BACKGROUND

Pancreaticobiliary maljunction (PBM), an anomalous union of the pancreatic duct with the common bile duct, has frequently been shown to be associated with biliary carcinoma. However, the mechanism of carcinogenesis is unknown.

METHODS

Mutations of the K-ras oncogene were examined in cancerous and noncancerous biliary tract epithelium of 20 patients with PBM by an extraction of DNA from surgically resected histologic specimens. DNA was analyzed by a polymerase chain reaction single strand conformation polymorphism (PCR-SSCP) method and direct sequencing.

RESULTS

An abnormally mobilized DNA band was detected not only in cancerous epithelium but also in hyperplastic, metaplastic, and inflammatory epithelium of the gallbladder and/or common bile duct in patients with PBM. Among the biliary epithelium of patients with PBM, point mutation of K-ras oncogenes were detected in 4 of 5 (80%) cancerous epithelium, 7 of 12 (58%) hyperplastic and metaplastic epithelium, and 8 of 18 (44%) inflammatory epithelium, whereas no point mutation of the K-ras oncogene was detected in the gallbladder epithelium in 3 control patients without PBM. Direct sequence analysis of the K-ras oncogene revealed the mutation at codon 12 substituting the wild-type glycine (GGT) for aspartic acid (GAT) in all cancerous lesions of patients with PBM. Simultaneous two-point mutations from the wild-type glycine (GGC) to arginine (CGC) at codon 13 associated with the mutation at codon 12 were also found in one case of gallbladder carcinoma and one case of bile duct carcinoma.

CONCLUSIONS

K-ras gene mutation is involved in the carcinogenesis of biliary tract epithelium in patients with PBM, and appears to be a high risk factor for carcinogenesis of the biliary tract.

[Prospective randomized trial comparing 1/2 FAM (5-fluorouracil (5-FU) + adriamycin + mitomycin C) versus palliative therapy for the treatment of unresectable pancreatic and biliary tract carcinomas (the 2nd trial in non-resectable patients). Japanese Study Group of Surgical Adjuvant Therapy for Carcinomas of the Pancreas and Biliary Tract]

The efficacy of 1/2 FAM, which consists of 5-fluorouracil (5-FU), adriamycin (ADM) and mitomycin C (MMC), was compared with that of palliative treatment in patients with unresectable pancreatic and biliary tract carcinomas in a multicenter randomized trial. The patients assigned to 1/2 FAM group were treated with 5-FU 200 mg/m2/day IV, ADM 15 mg/m2/day IV and MMC 5 mg/m2/day IV. These 3 drugs were given concurrently as the initial dose within a week after palliative operation, and this regimen was repeated for at least 2 whole courses, at 4-week intervals before the next course of therapy. Those randomized to the control group were subjected to palliative treatment alone. Completely eligible for analysis were 42 cases of the 1/2 FAM group and 41 of the control group. There was no significant difference between the groups with respect to the overall and differentiated survival times according to the tumor sites and the clinical efficacy. As for the duration of 50% inhibition of tumor progression, a significantly better outcome was obtained in 1/2 FAM group. Tumor progression was most significantly inhibited in patients with gallbladder carcinoma. In 1/2 FAM group, tumor reduction was achieved in 1 CR and 2 PR patients. The most frequent adverse reaction was gastrointestinal manifestations, along with diarrhea and alopecia. 1/2 FAM did not contribute to the life prolongation, but inhibited the tumor progression for a significantly longer duration and, to a lesser extent, reduced the tumor size in unresectable pancreatic and biliary tract carcinomas. This regimen is suggested to be useful particularly in the treatment of the latter carcinoma.

K-ras point mutations in cancerous and noncancerous biliary epithelium in patients with pancreaticobiliary maljunction

BACKGROUND

Pancreaticobiliary maljunction (PBM), an anomalous union of the pancreatic duct with the common bile duct, has frequently been shown to be associated with biliary carcinoma. However, the mechanism of carcinogenesis is unknown.

METHODS

Mutations of the K-ras oncogene were examined in cancerous and noncancerous biliary tract epithelium of 20 patients with PBM by an extraction of DNA from surgically resected histologic specimens. DNA was analyzed by a polymerase chain reaction single strand conformation polymorphism (PCR-SSCP) method and direct sequencing.

RESULTS

An abnormally mobilized DNA band was detected not only in cancerous epithelium but also in hyperplastic, metaplastic, and inflammatory epithelium of the gallbladder and/or common bile duct in patients with PBM. Among the biliary epithelium of patients with PBM, point mutation of K-ras oncogenes were detected in 4 of 5 (80%) cancerous epithelium, 7 of 12 (58%) hyperplastic and metaplastic epithelium, and 8 of 18 (44%) inflammatory epithelium, whereas no point mutation of the K-ras oncogene was detected in the gallbladder epithelium in 3 control patients without PBM. Direct sequence analysis of the K-ras oncogene revealed the mutation at codon 12 substituting the wild-type glycine (GGT) for aspartic acid (GAT) in all cancerous lesions of patients with PBM. Simultaneous two-point mutations from the wild-type glycine (GGC) to arginine (CGC) at codon 13 associated with the mutation at codon 12 were also found in one case of gallbladder carcinoma and one case of bile duct carcinoma.

CONCLUSIONS

K-ras gene mutation is involved in the carcinogenesis of biliary tract epithelium in patients with PBM, and appears to be a high risk factor for carcinogenesis of the biliary tract.

Intrahepatic sarcomatous cholangiocarcinoma

A 77-year-old man, diagnosed with a liver tumor, was referred to our hospital. Abdominal ultrasonography demonstrated a low echoic mass in the liver S2 region, and abdominal CT confirmed the presence of a round low-density mass 7 cm in diameter. Enhanced angio-computed tomography (CT) showed a ring-like form with a pale periphery. In the delayed phase of angio-CT, the inside of the mass was enhanced, showing septal stricture. Abdominal magnetic resonance imaging (MRI) revealed a heterogenous low intensity area in T1-weighted images, with a clear high intensity border becoming apparent in T2-weighted images. Stretching of the hepatic artery was evident on the arterial phase of angiography, while an avascular area was apparent in the lateral segment of the liver in the portal phase. Lateral segmentectomy was performed. The size of the tumor was 6 x 6 x 5 cm. On macroscopic cross section, it was white and clearly demarcated from the surrounding tissue. Microscopic observation of H&E-stained specimens did not show any glandular formation. The tumor consisted of an irregular fascicular arrangement of spindle-shaped and round cells with poor intercellular adhesion. While there was no region containing differentiated epithelial components, silver impregnation staining revealed structures resembling regenerating bile ducts. The tumor cells were positive for wide-keratin, and for vimentin staining. Tumor cells were carcinoembryonic antigen (CEA)-positive and alpha-feto protein (AFP)-negative. From the above findings, the tumor was judged to have originated from epithelium rather than from mesenchymal elements. The final diagnosis was intrahepatic cholangiocarcinoma with secondary sarcomatous transformation, rather than hepatocellular carcinoma.

Mutagenicity of bile and pancreatic juice from patients with pancreatico-biliary maljunction

We attempted to detect mutagenic activity in bile and pancreatic juice from patients with biliary tract disease using the spore rec assay and wild (H17) and mutant (M45) strains. Three bile samples out of 5 obtained from patients with pancreatico-biliary maljunction showed positive reaction in the spore rec assay, and all contained a high level of amylase activity, while 300 microliters of bile samples obtained from 10 control patients without pancreatico-biliary maljunction did not show any positive reaction. Moreover, 300 microliters of the in vitro mixture of bile with an equal volume of pancreatic juice also showed a positive reaction after treatment for 12 days at 37 degrees C or for 10 min at 100 degrees C, suggesting that they were very stable and long-acting in vivo. These data suggest that possible mutagens might be formed by the mixing of bile with pancreatic juice regurgitated into the biliary tract, and that there might be a relationship to biliary tract cancer which often accompanies pancreatico-biliary maljunction.

[Local spread of carcinoma of the esophagus by perineural invasion]

For clarification of the clinico-pathological features of carcinoma of the esophagus by perineural invasion (pni), 107 resected specimens were histologically examined. A correlation between pni and other findings, including clinical results, was sought. Pni was found in 31 patients (29.0%). It was found in no cases without adventitial cancerous invasion, at 26.3% in a1, 36.5% in a2 and 66.7% in a3. Pni would thus appear to be closely correlated with the depth of invasion. It also showed correlation with lymph-canal invasion but not with venous invasion or lymph node metastasis. Pni positivity was the same regardless of patient's age and sex, as well as tumor size, location and histological differentiation. In patients who had undergone preoperative radiotherapy, lymph-canal and venous invasion were noted to have markedly decreased but not pni. Curative resection was carried out in 57.9% of the pni negative patients and in 32.3% of the pni positive. Local recurrence was observed in 30.0% of pni positive and only 4.5% of negative cases. The cumulative survival rate was not significantly less in positive compared to negative patients.

The clinical course of acquired aplastic anemia in childhood; a retrospective study

We reviewed the clinical courses of 38 children with acquired aplastic anemia (AA). The patients were classified according to the severity criteria by the Japanese Ministry of Health and Welfare (JMHW) Study Group (22 severe, 15 moderate, 1 mild). Early death was observed only in severe cases. Eight of the non-severe cases progressed to severe in 0.5-125 months, and the long-term survival rate of non-severe AA did not differ from that of severe AA. The frequency of lymphocytes in the bone marrow was significantly higher, and the peripheral blood neutrophil count was lower in patients who died within a year, and these patients should be treated as very severe. These findings suggest that the JMHW Study Group criteria are useful for identifying AA patients with a poor prognosis, but even non-severe cases should be repeatedly evaluated. Sixteen of the 33 patients treated with corticosteroids and/or anabolic steroids (AS) showed hematological recovery. Bolus methylprednisolone (mPSL) therapy was effective in one of the 8 patients. Allogenic marrow transplant (BMT) was performed on 3 patients. One died from sepsis and engraftment was not achieved in the other two. Trilineage recovery was obtained in 3 of 6 patients treated with rhG-CSF and rhEPO with or without AS, and hemopoiesis has been maintained 6-12 months after discontinuation in 2 cases. In the other 3 patients, the neutrophil count showed transient increase. Therefore, the treatment for severe AA patients, who have no sibling donor for BMT, should be started with the combination therapy including these cytokines.

The carboxyl domain of zinc fingers of the Evi-1 myeloid transforming gene binds a consensus sequence of GAAGATGAG

Inappropriate expression of the Evi-1 zinc finger gene is associated with myeloid leukemia and myelodysplastic syndromes in mice and humans and has been hypothesized to contribute to pathology by blocking myeloid differentiation. Evi-1 contains two domains of zinc fingers, an amino-terminal domain of seven fingers and a carboxyl domain of three fingers. The first domain binds a consensus sequence of GA(C/T)AAGATAAGATAA in binding and amplication reactions or GATA repeat containing regions of genomic DNA. The experiments described here, establish a consensus sequence for the carboxyl domain of zinc fingers consisting of GAAGATGAG. Unlike the first domain, the consensus sequence established for the carboxyl domain is identical to that which would be predicted by the current rules relating to C2H2 zinc fingers and DNA recognition. Substitution of sequences in finger 8 with those in finger 9, demonstrate that the individual fingers bind the predicted region of the consensus sequence. In an attempt to engineer binding of constructs containing the carboxyl domain, a variety of mutations were made in the middle finger that would be predicted to change the consensus sequence in specific ways. Remarkably, most of the mutations were deleterious and destroyed specific DNA binding. Although Evi-1 contains potential transcriptional activation domains, it was not able to activate gene transcription from CAT constructs containing the consensus sequence.

DNA-binding specificity and trans-activating potential of the leukemia-associated E2A-hepatic leukemia factor fusion protein

Hybrid transcription factors, resulting from gene fusions in the wake of chromosomal translocations, have been implicated in leukemogenesis, but their precise contributions to oncogenic conversion remain unclear. The E2A-HLF fusion gene, formed by a t(17;19)(q22;p13) in childhood pro-B-cell acute lymphoid leukemia, encodes a hybrid protein that contains the trans-activation domain of E2A (E12/E47) linked to the bZIP DNA-binding and dimerization domain of hepatic leukemia factor (HLF). Here we report that both HLF and E2A-HLF bind to a 10-bp consensus sequence, 5'-GTTACGTAAT-3', with a core dyad-symmetric motif characteristic of the bZIP scissors-grip model of DNA binding. A probe containing this sequence bound chimeric E2A-HLF proteins in nuclear extracts of a leukemic cell line (UOC-B1) containing the t(17;19), as demonstrated by complexes supershifted with antibodies specific for amino-terminal epitopes of E2A or carboxyl-terminal eptiopes of HLF. E2A-HLF functioned as a potent trans activator of reporter gene expression from a plasmid that contained the consensus DNA-binding sequence. Interestingly, wild-type HLF was restricted in its capacity to act as a trans activator, functioning in human fetal kidney cells but not HepG2 hepatocarcinoma cells or NIH 3T3 mouse fibroblasts. The ability of the E2A-HLF hybrid protein to bind DNA in a sequence-specific manner and trans activate the expression of artificial reporter genes suggests that it could subvert transcriptional programs that normally control the growth, differentiation, and survival of lymphoid progenitor cells.

Establishment and characterization of a malignant melanoma cell line (YP-MEL) derived from a patient with neurocutaneous melanosis

A cell line, YP-MEL, was established from an intracranial malignant melanoma occurring in a neurocutaneous melanosis (NCMsis) patient. The established cell line was successfully cultured in serum-free medium with a doubling time of 41 h. The cells were refractile and small in size, with occasional pigmented giant cells. Histochemical and immunohistochemical features were compatible with common malignant melanoma and its cell line. Chromosome analysis revealed many supernumerary chromosomes and marker chromosomes including double minutes (DMs). When transplanted into nude mice, YP-MEL formed tumors histologically consistent with the original tumor. Addition of sera to the medium caused cellular spreading and elongation of cytoplasmic processes with an increase of melanin contents and tyrosinase activity. Because there was no melanoma cell line derived from a NCMsis patient, YP-MEL might be a beneficial tool for study on NCMsis.

Four of the seven zinc fingers of the Evi-1 myeloid-transforming gene are required for sequence-specific binding to GA(C/T)AAGA(T/C)AAGATAA

Expression of the Evi-1 gene is activated in murine myeloid leukemias by retroviral insertions and in human acute myelogenous leukemia by translocations and inversions involving chromosome band 3q26 where the gene resides. Aberrant expression of the Evi-1 gene has been shown to interfere with myeloid differentiation, which is proposed to be the basis for its role in leukemias. The Evi-1 gene encodes a 145-kDa DNA-binding protein containing two domains of seven and three Cys2-His2 zinc fingers. Previous studies identified a portion of the consensus DNA-binding sequence for the first domain of zinc fingers. The experiments presented here extend these studies and demonstrate that the first domain recognizes a consensus of 15 nucleotides consisting of GA(C/T)AAGA(T/C)AAGATAA. The first three fingers of the first domain do not detectably bind DNA but contribute to the binding by conferring a relative specificity for GACAA verses GATAA in the first position. The first three fingers also contribute to optimal binding of the 15-nucleotide consensus sequence.

[Treatment and prognosis after late relapse in childhood acute lymphoblastic leukemia]

We evaluated the clinical courses and laboratory features in 13 late-relapse cases of 55 children with acute lymphoblastic leukemia who had been in complete remission for longer than their years. In 8 of 13 cases, leukemia relapsed in bone marrow; 2 with testicular, 1 with central nervous system and one with ovarian involvement. Further, extramedullary relapse not involving bone marrow occurred in 5 cases (4 testicular and 1 CNS). Late-relapse was more frequently observed in boys (37.5%) than in girls (4.4%). Initial age and leukocyte counts were of no value in predicting late-relapse. The relapse rate in cases initially treated by the VPL regimen was twice that of those by a multi-drug regimen. A second prolonged remission was achieved in 5 of 10 cases by combinations of intensive chemotherapy (modified HEX) and irradiation to the testes or CNS. On the contrary, all late relapse patients initially treated by the multi-drug chemotherapy had a poor outcome. More intensive chemotherapy, including high-dose chemoradiotherapy and bone marrow transplantation, should be employed in this group of patients.

[High-dose busulfan, VP-16 and ACNU therapy with stem cell transplantation for the treatment of children with acute leukemia]

In order to strengthen the anti-leukemia effect, we developed a new conditioning regimen with high dose busulfan, VP-16 and ACNU (BVA) for cytoreduction before stem cell transplantation. Fourteen patients with refractory acute leukemia received allogeneic bone marrow transplantation (BMT) or peripheral blood stem cell transplantation (PBSCT) after conditioning with the BVA regimen, 7; allogeneic BMT, 1; syngeneic BMT, 6; PBSCT. # Seven patients were transplanted in the first complete remission, and 8 patients were in their second or third remission. Although total body irradiation or cyclophosphamide was not included in this regimen, engraftment was obtained in all cases. Two patients suffered relapse, and one patient died of cytomegalovirus interstitial pneumonitis (IP) 64 days after PBSCT. The other 11 patients are alive and free of disease at a median follow up time of 647 days (98-1235 days). Major regimen-related toxicity was pulmonary complications such as IP (3 cases) and pulmonary edema (2 cases). However, all patients recovered rapidly following steroid therapy. The results indicate that this conditioning regimen is highly effective for the treatment of childhood acute leukemia.

A patient with early gallbladder cancer derived from a Rokitanski-Aschoff sinus

We present herein a case of a 40-year-old male with early gallbladder cancer derived from a Rokitanski-Aschoff sinus (RAS). The patient originally presented at our hospital with epigastric discomfort, following which a diagnosis of adenomyomatosis (ADM) of the gallbladder was made, and a cholecystectomy performed. Histopathological examination of the resected specimen revealed a 7-mm well-differentiated papillo-tubular adenocarcinoma in the RAS epithelium in the body of the gallbladder. The RAS extended to the "pm" layer but the adenocarcinoma was an in situ lesion localized within the RAS epithelium. Considering the difficulties in making an early diagnosis of gallbladder cancer, active surgery should be performed for patients in whom ADM is seen in the gallbladder.

The usefulness of intraoperative drip infusion cholangiography during laparoscopic cholecystectomy

Intraoperative cholangiography during laparoscopic cholecystectomy has been considered to be a necessary examination because incidental injury to the common bile duct must be avoided. We performed 93 intraoperative drip infusion cholangiographies among 103 laparoscopic cholecystectomized patients as simple examinations by using iotroxic acid. The best drip infusion time was determined to be 20 min and good pictures were obtained from 10 to 60 min after the end of the drip. Nine patients with liver dysfunction and a poor radiograph had poor cholangiograms. Clear cholangiograms were obtained in 79 patients: four had a long remnant cystic duct and, in one case, a common bile duct stenosis was found by endoclip. The findings in these five cases helped us to correct failures during operation.

[Study of nuclear DNA content with flow cytometer in pancreatic diseases]

Benign and malignant diseases of the pancreas were compared with nuclear DNA content by flow cytometry, and the relationship between nuclear DNA content and histopathological findings was studied in ductal carcinoma of the pancreas. The nuclear DNA content in the malignant disease was higher than that in the benign disease. No significant correlation between nuclear DNA content and histopathological findings was observed in ductal carcinoma of the pancreas. A tendency for the nuclear DNA content to increase in proportion to the tumor size and the stage was, however, observed. Study of the nuclear DNA content is believed to be an effective adjuvant modality in differential diagnosis between benign and malignant disease of the pancreas.

[Experimental studies on the effects of alpha-tocopherol in small intestinal ischemia and reperfusion injury]

In the present study, we quantified the biochemical [thiobarbituric acid (TBA) reactants, superoxide dismutase (SOD) and vitamin E] and histologic changes in the small intestinal tissue after ischemia and/or reperfusion. Sixty-seven Wistar rats were divided into 7 groups; N group: control, A-I group: 30 min. ischemia, A-II group: 120 min. ischemia, B-I group: Declamp after 30 min. ischemia, B-II group: 30 min. reperfusion after 30 min. ischemia, B-III group: 30 min. reperfusion after 120 min. ischemia, E group: vitamin E administration 30 min. reperfusion after 30 min. ischemia. The levels of TBA reactants were significantly different between A-II and B-II, B-II and E (all p less than 0.01). For SOD, there were significant differences between N and B-I (p less than 0.01), N and E (p less than 0.05). For vitamin E, there were significant differences between A-I and B-I, A-I and B-I, B-II and E (all p less than 0.01). Histologic changes showed that the grade of tissue injury was more severe in B-I and B-II than in A-I, and was less in E than in B-II. It is suggested that vitamin E protected cells from injury due to oxygen free radicals.

Some considerations on the biology of pancreatic serous cystadenoma

Five cases of pancreatic serous cystadenoma were examined pathologically, and their nuclear DNA ploidy patterns were determined. Four were unifocal tumors, and one was a multifocal tumor. The four unifocal tumors were typical serous cystadenomas. However, the multifocal tumor exhibited an increased N/C ratio, irregular nuclear margins, various-sized nuclei, coarse nuclear chromatin, and neural invasion. All tumor cells were stained with antiCA19-9 but none with antiCEA. In the antiCA19-9 staining, the four unifocal tumors and the tumors of the pancreatic tail in the multifocal case were positive only on the apical membrane, whereas the tumor cells of the pancreatic head in the multifocal case were positive within the whole cytosol. The unifocal tumors were diploid with a DNA Index (DI) of 1.0 and proliferation indices (PI) from 4.9 to 20.9% with a mean of 14.4%. In the multifocal case, the tumor in the pancreatic head was aneuploid (DI = 1.9) and had a PI of 27.8%. The multifocal sites in the pancreatic body were aneuploid (DI = 1.9) with a PI of 22.4%. We suggest that the biological property of serous cystadenoma should be revisited.

Three cases of solid and cystic tumor of the pancreas. Analysis comparing the histopathological findings and DNA histograms

The pathological findings in three cases of solid and cystic tumor (SCT) of the pancreas were compared with the nuclear DNA histogram obtained by flow cytometry. One case involved malignant SCT with liver metastases. Two of the cases were benign SCT. In the malignant SCT, cellular atypia and mitotic figures were extensively observed. The proliferation index (PI) was 25, and the DNA index (DI) was 1.65. In the benign SCT, cellular atypia and mitotic figures were rarely observed. The PI was 8 and 13, respectively, and the DI was 1.0 in both cases. The proliferative activity and the biological malignant potential of the malignant SCT were thought to be higher than those of the benign SCT.

Multifocal pancreatic serous cystadenoma with atypical cells and focal perineural invasion

A case of multifocal pancreatic serous cystadenoma with atypical cells is reported. The patient was a 72-yr-old female who complained of jaundice. The distal common bile duct was obstructed, and the proximal bile duct was remarkably dilated on cholangiography. The main portal vein was obstructed and collateral vessels had developed on portal angiography. Total pancreatectomy was performed. The resected specimen contained one tumor in the head of the pancreas, five in the body, and one in the tail. The tumors of the head and body were morphologically the same. Microscopically, both contained spongelike multilocular cysts on their cut surfaces. These cysts were covered with low cuboid epithelium containing clear cytoplasm and abundant glycogen. Neural invasion was also found. The tumor cells exhibited an increased N/C ratio, variable nuclear size, irregular nuclear margins, and coarse nuclear chromatin. These tumors had aneuploid nuclear DNA with a DNA index of 1.9 and a proliferation index of 0.28. We feel that it is necessary to reconsider the biological concept of serous cystadenoma.

Bile acids and biliary carcinoma in pancreaticobiliary maljunction

Pancreaticobiliary maljunction is frequently associated with biliary carcinoma, whether or not there is choledochal dilatation. In this anomalous condition, pancreatic juice regurgitates and the mixture of bile and pancreatic juice stagnates in the biliary tree. In cystic choledochal dilatation, cancers arise, mainly in the dilated bile ducts, while in patients not having cystic dilatation, tumors arise in the gallbladder. Gallbladder bile and/or bile duct bile from fifteen cases of pancreaticobiliary maljunction, including five cancer patients, was analysed biochemically and compared with control bile from 6 patients with a normal pancreaticobiliary junction. Bile levels of pancreatic enzymes were extremely high in the anomalous junction group. In the bile duct bile from patients with cystic choledochal dilatation with pancreaticobiliary maljunction, the concentrations of deoxycholic acid (DCA), lithocholic acid (LCA) and unconjugated bile acid fractions were increased regardless of the presence of cancer. Increases of these bile acid fractions, which are known to have a cancer-promoting effect, were also seen in gallbladder bile from the cancer patients without cystic dilatation.

Establishment and characterization of a murine megakaryoblastic cell line growing in protein-free culture (L8057Y5)

A murine megakaryoblastic cell line growing in protein-free culture (L8057Y5) was established from an experimentally induced murine leukemia (MK8057). Most of the Y5 cells were small and blast-like, with 2-4N in DNA content. Also, large cells possessing a lobulated nucleus characteristic of megakaryocytes, which showed polyploidization to more than 4N up to 16N, were occasionally seen. Nearly 5% of the total number of Y5 cells were positive for acetylcholinesterase reaction. The survival time of C3H/He mice after injection with Y5 cells was longer than that of mice injected with the original MK8057 cells. The colony-forming ability of Y5 cells in the spleen of the lethally irradiated mouse was much lower, whereas the number of in vitro colonies derived from Y5 was greater than that of MK8057. The plating efficiency of colony formation in serum-free methylcellulose culture was higher at a low O2 tension. Conditioned medium of Y5 cells enhanced colony formation as well as 3H-TdR uptake by Y5 cells, which implies that Y5 cells may produce autocrine growth factor(s). mRNAs for IL-6, LIF, and INF-gamma were expressed in Y5 cells; these cytokines may have roles in the growth mechanisms of the cell line.