Flow cytometric analysis of DNA heterogeneity in superficial carcinoma of the esophagus

BACKGROUND

There are few studies of flow cytometric analysis for DNA heterogeneity of patients with superficial carcinoma of the esophagus limited to the epithelium or superficially invading the lamina propria or submucosa.

METHODS

Flow cytometric analysis of cellular DNA content was performed on superficial carcinomas of the esophagus using paraffin embedded blocks of the surgically resected specimens from 56 patients. To evaluate the intratumoral DNA heterogeneity, a total of 141 samples of the 56 tumors were analyzed, depending upon the tumor size.

RESULTS

One or two of the samples was available from 18 of 19 patients with tumors 2 cm or less in greatest dimension, whereas more than three of the samples were available from 22 of 37 patients with tumors 2.1 cm or greater in dimension (P < 0.003). Of 56 tumors, 40 (71.4%) exhibited DNA aneuploidy; DNA heterogeneity was found in 26 tumors (46.4%). The remaining 16 tumors exhibited DNA diploidy. Two of the five tumors that were limited to the epithelium had DNA heterogeneity. The mean dimension of the tumors with DNA heterogeneity was significantly greater (5.8 +/- 2.8 cm) than those exhibiting DNA diploidy (2.3 +/- 1.1 cm) and DNA aneuploidy without heterogeneity (2.9 +/- 2.4 cm). Recurrences after esophagectomy were detected in 6 of the 56 patients; the DNA ploidy pattern of these six patients exhibited DNA heterogeneity.

CONCLUSION

The incidence of DNA heterogeneity increases as tumor size increases and is associated with an increased risk of tumor recurrence after esophagectomy in patients with superficial carcinoma of the esophagus.

Chemical stimulation of the nucleus tractus solitarii decreases spinal cord blood flow in anesthetized rats

L-Glutamate was microinjected into the nucleus tractus solitarii (NTS) in anesthetized (chloralose and urethane), paralyzed and artificially ventilated rats, and spinal cord blood flow (SCBF) was determined using a combination of labeled microspheres. Unilateral chemical stimulation of the NTS (n = 13) significantly decreased SCBF in the cervical cord from 43 +/- 6 (mean +/- SEM) to 28 +/- 4 (P < 0.05), in the thoracic cord from 35 +/- 3 to 24 +/- 4 (P < 0.01), and in the lumbar cord from 49 +/- 3 to 40 +/- 3 ml min-1 (100 g)-1 (P < 0.05). The decrease in SCBF was not due to the decrease in arterial blood pressure (ABP) because the SCBF during the chemical stimulation of the NTS was significantly smaller (P < 0.05) than the SCBF during controlled hemorrhagic hypotension (n = 11). Chemical stimulation of the NTS did not affect the reactivity of the spinal cord vessels to hypercapnia (n = 5). Microinjection of the vehicle solution into the NTS had no effects on spinal cord circulation (n = 9). These results suggest that the cell bodies within the NTS may play a role in the control of spinal cord circulation.

Direct hemoperfusion under infrahepatic inferior vena caval isolation for the intraarterial chemotherapy of pelvic tumors

A new simple technique consisting of direct hemoperfusion under infrahepatic inferior vena caval isolation for intraarterial chemotherapy of pelvic tumors is herein described. The inferior vena cava is occluded at the infrahepatic level by means of balloon inflation using a balloon-tipped catheter (16F), which is placed through the right greater saphenous vein. The isolated infrahepatic vena caval blood is withdrawn by a centrifugal pump through a catheter (16F) in the contralateral greater saphenous vein and is filtered by direct hemoperfusion during intraarterial infusion of anticancer drugs. Venous reentry is provided by the central lumen of the balloon-tipped catheter. This procedure was used sequentially on two different occasions to treat a patient with an extensive pelvic tumor. Good hemodynamic stability and a reduction of the systemic drug toxicities were confirmed in both trials. Therefore, we believe that this technique is technically feasible and highly effective in reducing systemic toxicities during high-dose intraarterial chemotherapy for pelvic tumors.

Occult lymph node metastasis in gastric cancer with submucosal invasion

To evaluate more precisely the incidence of lymph node metastasis in patients with submucosally invaded (sm) gastric cancer, three additional sections were made from the remaining half of 1,794 lymph nodes taken from 57 patients, for a detailed reexamination. Lymph node metastasis was demonstrated in 19 nodes from 11 patients by the initial routine examination; however, the detailed reexamination showed cancer involvement in a further nine lymph nodes from eight patients. Of these eight patients, metastasis had not been detected in any lymph nodes by routine examination in six. Macroscopically, the lesion was of the depressed or mixed type in six of the eight patients. From the intranodal location and growth pattern of the cancer foci, lymph nodes with occult metastasis were divided into the marginal sinus type, the medullary sinus type, and the mixed type, with the marginal type being found most frequently. The overall incidence of lymph node metastasis in patients with sm gastric cancer was as high as 29.8% (17/57) in this series. Moreover, a follow-up study revealed that two patients with occult metastasis died of cancer recurrence postoperatively. Accordingly, systematic regional lymph node dissection should be carried out at the time of surgery for sm gastric cancer.

Caudal ventrolateral medullary depressor area controls cerebral circulation via rostral ventrolateral medullary pressor area

The cerebral blood flow (CBF) was determined by radiolabeled microsphere technique in urethane (1.1-1.5 g.kg-1, i.p.) anesthetized Wistar rats. Microinjection of L-glutamate (1.7 nmol) into the ventrolateral medullary depressor area (VLDA) produced a significant (P < 0.01) decrease in CBF from 64 +/- 9 (mean +/- S.E.M.) to 48 +/- 9 ml.min-1.(100g)-1 and a significant (P < 0.01) increase in cerebrovascular resistance (CVR) from 1.7 +/- 0.2 to 2.4 +/- 0.4 mmHg per [ml.min-1.(100g)-1] in the cerebral cortex ipsilateral to the stimulated VLDA side but not in other structures such as brain stem and cerebellum (n = 9). Cervical sympathectomy blocked the decrease in CBF and increase in CVR elicited by chemical stimulation of the VLDA (n = 10). Depression of the ventrolateral medullary pressor area (VLPA) neurons induced by microinjection of muscimol into the VLPA blocked the CBF decrease and CVR increase following chemical stimulation of the VLDA (n = 11). Microinjection of the vehicle solution into the VLDA had no effects on systemic and cerebral circulation (n = 7). These results suggest that a vasoconstrictor pathway to control cerebral vessels involves an excitatory projection from the VLDA to the VLPA and the changes in cerebral circulation are mediated by the cervical sympathetic nerves.

A modified invasion-3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide assay for quantitating tumor cell invasion

Reconstituted basement membrane matrix (Matrigel) has been utilized for in vitro assay of tumor cell invasion in recent years. In the conventional chamber for the invasion assay, however, a large number of cells passed easily through the center of the Matrigel-coated filter because the Matrigel layer could not be completely uniform by the meniscus formation. To prevent the meniscus phenomenon of the Matrigel layer, we devised a water-repellent treatment of the inside wall of the assay chamber with paraffin. Consequently, very few erythrocytes passed through the Matrigel-coated filter of this modified chamber with the erythrocyte assay, which was used to demonstrate the evenness and uniformity of the Matrigel layer on the filter. For quantitating a small number of cells which invaded through the Matrigel-coated filter by the invasion assay, a tetrazolium-based colorimetric 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide) assay was used. The invasive abilities of the eight different cells were determined by this invasion-3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium+ ++ bromide assay using the modified chamber with a filter coated with 70 microliters of the 0.2-mg/ml Matrigel. After 72 h of incubation, the malignant cell lines significantly exceeded the normal cell lines in the percentage of invasion (P < 0.01). Therefore, the modified invasion-3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium+ ++ bromide assay provides a simple, easily reproducible in vitro assay for quantitating tumor cell invasion.

[Diagnosis of sinus venosus atrial septal defect by transesophageal color Doppler and two-dimensional echocardiography]

Diagnosis of sinus venosus atrial septal defect based on transthoracic color Doppler and two-dimensional echocardiography is often difficult. We recently experienced two cases of sinus venosus atrial septal defect which were correctly diagnosed using transesophageal color Doppler and two-dimensional echocardiography. Transthoracic color Doppler flow imaging did not demonstrate the atrial septal defect or the shunt flow across the defect in either case. Transesophageal two-dimensional echocardiography visualized a defect in the upper most portion of the interatrial septum in one case, and transesophageal color Doppler flow mapping detected a left-to-right shunt across the defect in both cases. Transesophageal color Doppler flow mapping also demonstrated the flow signal of the right upper pulmonary vein into the right atrium near its junction with the superior vena cava in each case. The diagnoses of sinus venosus atrial septal defect and combined partial anomalous pulmonary venous return were confirmed by surgery in both cases. Transesophageal color Doppler and two-dimensional echocardiography are very useful in diagnosing sinus venosus atrial septal defect and combined partial anomalous pulmonary venous return.

Cloning and characterization of a tryptophanase gene from Enterobacter aerogenes SM-18

A tryptophanase gene from Enterobacter aerogenes SM-18 was cloned and sequenced. The structural gene for tryptophanase, tnaA, consisted of 1389 bp encoding 462 amino acid residues, and its nucleotide sequence and deduced amino acid sequence showed significant homology to those of tnaA from Escherichia coli K12. A short open reading frame consisting of 31 amino acid residues was found upstream of tnaA, and it showed some similarity to the E. coli tnaC gene known to be a cis-acting regulatory element for transcription. A partial open reading frame homologous to the 5' end of E. coli tnaB was observed at the 3'-flanking region of tnaA. These genes may thus constitute an operon as in E. coli.

Mouse tumor necrosis factor receptor type I: genomic structure, polymorphism, and identification of regulatory regions

The mouse tumor necrosis factor receptor (TNFR)-I gene was cloned, sequenced, and characterized. The nucleotide sequence analysis shows that the TNFR-I is composed of 10 exons and nine introns. The first intron includes two simple dinucleotide repeat sequences, (GA)8 and (TC)9(TG)19. The (TC)9(TG)19 tandem repeat was found to be polymorphic in its length among various mouse strains. The nucleotide sequence of the 1076 bp 5' flanking region of the TNFR-I was also determined. Various possible regulatory sequences were identified in the 5' flanking region of the TNFR-I gene. For functional analysis, the 5' flanking region of the TNFR-I gene was isolated, ligated upstream of the luciferase reporter gene, and transiently transfected into L929, Hela, and a T cell hybridoma cell line. The results show that the isolated 5' flanking region has functional promoter activity and is responsible for constitutive expression of the TNFR-I gene. A series of truncated promoter constructs were generated and studied in a transient transfection system. Analysis of transient expression in L929 cells shows that the regions -1076/-939, -615/-425, and -425/-198 include positive regulatory elements, while the region -939/-615 may contain negative cis-acting elements for the constitutive expression of the TNFR-I. The shortest construct containing 198 bp of the 5' flanking region still has significant promoter activity, suggesting that the two GC-rich elements in this region may play an important role in the constitutive expression of the TNFR-I gene.

Deregulated c-fos modulates B cell responses to switch mediators

We examined effects of deregulated c-fos on the proliferation and differentiation of B cells in vitro, using splenic B cells from H2-c-fos transgenic mice. When these cells were cultured with lipopolysaccharide (LPS) plus recombinant interleukin 4 (rIL-4) (10(4) U/ml), the proliferative response of the B cells was augmented with any dose of LPS used. This augmented proliferation resulted in an increase in IgG1 production in the culture, at the lower concentrations of LPS (< 2.5 micrograms/ml). However, H2-c-fos B cells did not produce IgG1 in the culture at higher concentrations of LPS (> 5 micrograms/ml) probably due to the perturbation of B cell differentiation to antibody-forming cells. These results suggest that the deregulated expression of c-fos modulates the proliferation and differentiation of B cells stimulated with LPS plus rIL-4.

A new family of heparin-binding growth/differentiation factors: increased midkine expression in Wilms' tumor and other human carcinomas

Midkine (MK) and heparin-binding growth-associated molecule/pleiotrophin form a new family of heparin-binding growth/differentiation factors. We studied MK gene expression in human tumors. In normal human reference tissues, MK was highly expressed in the mucosal tissue of the small intestine, moderately in the thyroid, weakly in the tissues of the lung, colon, stomach, kidney, and spleen, and not at all in the liver. All of 6 surgically removed specimens of Wilms' tumor highly expressed MK. Also, a moderate to intense level of MK expression was noted in the majority of surgically removed hepatocellular carcinomas. The MK mRNA level was analyzed in a number of cultured and nude mice-transplanted lines of human tumors. In stomach, colon, pancreatic, lung, and esophageal carcinomas, a moderate to high level of MK expression was found in the majority of them. These results suggest an important role of MK in the development and/or biological behavior of tumors and raised a possibility to use MK as a diagnostic marker. Heparin-binding growth associated molecule/pleiotrophin mRNA was low or scarcely detectable in samples analyzed thus far except for significant levels of the expression that were observed in PA-1 teratocarcinoma cells and in some surgical specimens of Wilms' tumor.

Modified pancreaticogastrostomy following pancreaticoduodenectomy

A modified pancreaticogastrostomy without gastrotomy was performed in 46 patients undergoing pancreaticoduodenectomy for malignant or benign disease. Postoperative complications related to the modified pancreaticogastrostomy occurred in one patient (2%). Operative mortality was 4% and was unrelated to the pancreaticogastrostomy itself. During the first postoperative year, four patients died of causes unrelated to the original disease process, and nine patients died of recurrent carcinoma. The remaining 31 patients were alive and well at a mean follow-up of 20 months. Results of postoperative gastroscopy were normal in all patients studied. A modified pancreaticogastrostomy without gastrotomy is a safe and effective procedure for pancreatic reconstruction in pancreaticoduodenectomy.

Expression of the HN, F, NP and M proteins of Sendai virus by recombinant vaccinia viruses and their contribution to protective immunity against Sendai virus infections in mice

Recombinant vaccinia viruses (RVVs) expressing each of the haemagglutinin-neuraminidase (HN), fusion (F), nucleocapsid (NP) and matrix (M) proteins of Sendai virus were constructed to investigate their capacities to induce protective immunity against Sendai virus infections. The proteins expressed in cultured cells appeared to be authentic with respect to their antigenicity, electrophoretic mobility, surface expression of the HN and F proteins and, in the case of the HN protein, biological activities. Mice inoculated intranasally with these RVVs developed serum antibodies to the respective Sendai virus proteins, suggesting their in vivo expression. In mice immunized with RVV carrying either the HN or the F gene, growth of the challenging Sendai virus was almost completely suppressed in the lung, indicating their capacities to induce effective protective immunity against Sendai virus infections. In contrast, in mice immunized with RVV carrying the NP or M gene, the challenging virus propagated as well as in the control mice, but the virus titres were significantly lower at the late stage of infection than those in the control mice, suggesting that they can also induce protective immunity especially at the late stage of the challenge infection.

Inflammatory pseudotumor of the spleen: report of a case

A case of an inflammatory pseudotumor arising in the spleen of a 60-year-old Japanese male is described herein. This benign lesion is extremely rare, with only 12 cases, including our own, having been reported in the world literature. We preoperatively diagnosed the splenic tumor as a metastasis, due to the coexistance of advanced stage carcinoma in the sigmoid colon. However, after splenectomy, histopathological examination of the mass revealed an inflammatory process. Inflammatory pseudotumors often pose diagnostic difficulties because the clinical and radiologic findings are suggestive of malignancy. The clinical and pathological features of cases previously reported are reviewed following the presentation of this case.

B cell development is perturbed in bone marrow from c-fos/v-jun doubly transgenic mice

c-fos and c-jun gene products form a heterodimeric complex (AP-1) that regulates target gene expression by binding to a specific DNA sequence motif. In order to study a role of AP-1 (Fos/Jun) in growth and differentiation of immature B lineage cells, we have established and mated two independent transgenic mice carrying the mouse c-fos gene or the viral v-jun gene fused to the H-2K promoter. IL-7 dependent bone marrow cell culture from doubly transgenic (H2-fos/jun) mice demonstrated severe delay of early B cell development. Proliferation of pre-B cells in the fresh bone marrow from H2-fos/jun mice to IL-7 stimulation was very low. These results suggest that the deregulated production of AP-1 perturbs IL-7 mediated proliferation and differentiation of immature B cells.

Novel DNA polymorphism in the mouse tumor necrosis factor receptors type 1 and type 2

The introduction of the polymerase chain reaction (PCR) provides an entirely new means of analyzing DNA polymorphism and makes practical the analysis of length variation in simple-sequence tandem repeats of dinucleotides. In the process of cloning and sequencing the mouse genomic DNA for tumor necrosis factor (TNF) receptors type 1 and type 2, we identified two simple dinucleotide repeats within the noncoding regions of TNF receptor type 1 and three such sequences within TNF receptor type 2. PCR analysis of these sequences, using genomic DNA from 21 different inbred and wild mouse strains, as demonstrated by running the amplified products on sequencing gels, showed that the repeats are highly polymorphic. We identified seven alleles of TNF receptor type 2 and five alleles of TNF receptor type 1. Using these polymorphic markers in two sets of recombinant inbred strains of mice, the chromosomal localization of Tnfr-1 was mapped to mouse chromosome 6 and Tnfr-2 was located to the distal portion of mouse chromosome 4.

Rapid and marked induction of hepatocyte growth factor during liver regeneration after ischemic or crush injury

Liver injuries induced by ischemia or physical trauma are characterized by noninflammatory damage frequently observed in a clinical setting. When the liver of rats was injured by ischemic treatment or physical crushing, necrotic tissue degeneration occurred in several sites of lobulus within 24 hr. Hepatocyte growth factor, a potent mitogen for adult rat hepatocytes in primary culture, was markedly induced in the livers of rats injured by ischemia or physical trauma. In both cases, the hepatocyte growth factor messenger RNA level in the injured liver reached about 10 to 20 times that of the normal level during 12 to 24 hr after liver injury. The increase in hepatocyte growth factor messenger RNA correlated well with the degree of liver damage as evaluated by serum ALT activity in the sera of rats. In situ hybridization showed that hepatocyte growth factor messenger RNA expression occurs in nonparenchymal liver cells, primarily in Kupffer cells of the ischemic liver. After the increase of hepatocyte growth factor messenger RNA in the injured liver, a marked compensatory hepatocyte DNA synthesis occurred 48 to 72 hr after these treatments. These results suggest that hepatocyte growth factor acts as a hepatotropic factor for liver regeneration after noninflammatory liver damage caused by ischemia and physical crush, probably through a paracrine mechanism.

A novel core protein as well as polymorphic epithelial mucin carry peanut agglutinin binding sites in human gastric carcinoma cells: sequence analysis and examination of gene expression

The peanut agglutinin (PNA)-binding site is protein-bound Gal beta 1-->3GalNAc, and is a tumor-associated carbohydrate marker expressed in many human carcinomas. PNA-binding glycoproteins isolated from KATO-III human gastric carcinoma cells were deglycosylated by trifluoromethanesulfonic acid, and rabbit antibodies against the core proteins were used to screen a lambda gt11 expression library constructed from these cells. Two different core proteins were identified by this approach. One was polymorphic epithelial mucin (PEM), initially found in breast carcinomas. PEM mRNA was expressed in normal tissues of the stomach, colon, and lung, but not in the small intestine, thyroid, and spleen. High levels of PEM mRNA were detected in some nude mouse-transplanted carcinomas, i.e. colorectal, pancreatic, stomach, and lung carcinomas. The other core protein was a novel one called MGC-24, which has a molecular mass of 24 kDa, is rich in hydroxyl amino acids and cysteine, and lacks repeating motifs. The mature MGC-24 glycoprotein behaved as a high-molecular-mass one upon SDS-polyacrylamide gel electrophoresis even after neuraminidase treatment. Treatment with endo-alpha-N-acetylgalactosaminidase in the absence of neuraminidase significantly changed the staining pattern by anti-MGC-24, confirming that MGC-24 carried PNA-binding sites. MGC-24 mRNA was intensely expressed in normal tissues of the colon, small intestine and thyroid, and in some nude mouse-transplanted colorectal and pancreatic adenocarcinomas.

Effect of a dihydropyridine analogue, 2-[benzyl(phenyl)amino]ethyl 1,4-dihydro-2,6-dimethyl-5-(5,5-dimethyl-2-oxo- 1,3,2-dioxaphosphorinan-2-yl)-1-(2-morpholinoethyl)-4-(3-nitrophenyl)-3 -pyridinecarboxylate on reversing in vivo resistance of tumor cells to adriamycin

A newly synthesized dihydropyridine analogue, 2-[benzyl(phenyl)-amino]ethyl 1,4-dihydro-2,6-dimethyl-5-(5,5-dimethyl-2-oxo-1,3,2-dioxaphosphorina n-2-yl)-1- (2-morpholinoethyl)-4-(3-nitrophenyl)-3-pyridinecarboxylate (PAK-200), at 5 microM inhibited the efflux of [3H]vincristine from KB-C2 cells and increased the accumulation of [3H]vincristine in KB-C2 cells to a level similar to that in KB-3-1 cells. PAK-200 inhibited the photoaffinity labeling of P-glycoprotein in KB-C2 membranes by [3H]azidopine. At 5 microM, PAK-200 enhanced the cytotoxic effect of Adriamycin on drug-sensitive KB-3-1 cells, multidrug-resistant KB-8-5 cells, and two human colorectal carcinoma tumor lines, COK-28LN and COK-36LN, by factors of 2, 5, 2, and 3 times, respectively. The calcium antagonistic activity of PAK-200 was about 1000 and 5 times lower than that of another dihydropyridine analogue, nicardipine, and of verapamil, respectively. PAK-200 in combination with Adriamycin completely suppressed the growth of KB-3-1 and COK-36LN and partially suppressed the growth of KB-8-5 but had no significant effect on COK-28LN cells xenografted in nude mice. The level of MDR1 expression of COK-36LN was about 3 times higher than that of COK-28LN, but lower than that of KB-8-5 cells. These results suggest that the interaction of PAK-200 with P-glycoprotein may be partly correlated with the enhancement of the antitumor effect of Adriamycin on xenografted KB-8-5 and COK-36LN cells in nude mice.

Monoclonal antibodies against a human gastric cancer cell line with lung metastatic potential in nude mice define antigens with different expression between the primary and metastatic liver lesions

SCK-29 is a tumor cell line derived from human gastric adenocarcinoma with the feature of producing lung metastases when xenografted in nude mice. Monoclonal antibodies were produced against SCK-29 tumor cells or their glycoproteins prepared by affinity chromatography on a lectin-agarose column. Five antigens defined by the monoclonal antibodies MG-1 to MG-5 were expressed in a large number of gastric or colonic adenocarcinomas. Among the antigens, MG-1 and MG-3 proved to be tumor-associated, since they were detected only occasionally in normal tissues. MG-5 antigen was often detected in normal gastric mucosa but not in other tissues. The degree of expression of MG-1. MG-3 and MG-5 antigens differed considerably in metastatic lesions. In metastatic liver lesions of gastric adenocarcinoma, expression of these MG antigens was less marked than in primary tumors. MG-1 and MG-3 antigens were abolished by neuraminidase digestion and periodate oxidation. MG-5 antigen was likely to be a protein antigen, since it was resistant to neuraminidase digestion and to periodate oxidation but was sensitive to protease digestion.

Induction of Cellulase by Gentiobiose and Its Sulfur-Containing Analog in Penicillium purpurogenum

Cellulase induction by β-glucodisaccharides was investigated by using non-cellulase-induced mycelia of Penicillium purpurogenum P-26, a highly-cellulase-producing fungus. Gentiobiose induced significant amounts of cellulase compared with cellobiose when nojirimycin was added to the induction medium to inhibit extracellular β-glucosidase activity. Thiogentiobiose (6- S -β- d -glucopyranosyl-6-thio- d -glucose), a sulfur-containing analog of gentiobiose, was more effective for cellulase induction than gentiobiose even in the absence of nojirimycin. Thiogentiobiose appeared to be a gratuitous inducer since it was not metabolized during cellulase induction. Gentiobiose was formed from cellobiose by the intracellular β-glucosidase of P. purpurogenum. These findings indicate that gentiobiose is an active inducer of cellulase for this fungus and may possibly be formed by intracellular β-glucosidase from cellobiose.

A correlation between arterial ketone body ratio and concentration of beta-hydroxybutyrate as an indicator of hepatic functional reserve

We have investigated the correlation between the arterial blood ketone body ratio (AKBR) and beta-hydroxybutyric acid (HBAC) in the course of a 75 g glucose tolerance test. The correlation was revealed to be represented by an equation of Y = A + BX [X = log(HBAC), Y = log(AKBR)] with high significance. This expression existed in both normal individuals and patients with liver, biliary tract or pancreas disease. The postoperative course was unsatisfactory because of liver dysfunction in cases whose value B was more than -0.6 in bisegmentectomy and more than -0.45 in uni- or subsegmentectomy. The coefficient B in the equation was suggested to contribute to the evaluation of hepatic functional reserve.

Tumorigenicity, invasion, and metastasis of human gastric cancer in nude mice

Tumors derived from 105 patients with gastric cancer were subcutaneously heterotransplanted into nude mice in order to study their tumorigenicity and malignant behavior. Of the 105 gastric cancers, 45 were successfully transplanted (a 42.9% tumorigenesis rate). The tumorigenesis rate of Borrmann type 1 and 2 cancers (77.8%) was significantly higher than that of type 3 and 4 cancers (34.6%). Also, the tumorigenesis rate of differentiated carcinoma (57.1%) was significantly higher than that of undifferentiated carcinoma (30.9%). Spontaneous metastases from the subcutaneous tumors were observed in 5 of the 37 established tumor lines (13.5%), and macroscopic pulmonary metastases were common with one tumor line (SCK-29). Although most of the subcutaneous gastric cancers showed local expansion without distant metastasis, the same tumor cells implanted into the peritoneal cavity exhibited invasive growth and/or metastasis. Thus, the expression of a metastatic phenotype by human gastric cancer was influenced by the host microenvironment. The SCK-29 tumor line with its high metastatic potential may be useful for studies on the mechanism of blood-borne metastasis.