Endoscopic mucosal resection for colorectal neoplastic lesions

PURPOSE: Endoscopic mucosal resection, which is a new option for endoscopic polypectomy of colorectal polyps without stalks, was evaluated on its usefulness in polypectomy. METHODS: Three hundred thirty-seven lesions, which were removed by endoscopic mucosal resection between January 1990 and January 1993, were studied. The endoscopic configuration of neoplastic lesions were classified into four types: flat, sessile, large sessile with distinct lobulations, and semipedunculated. RESULTS: The 337 lesions included 243 adenomas, 30 mucosal cancers, 13 submucosal cancers, 3 carcinoids, 43 hyperplastic polyps, and 5 inflammatory polyps. Of the 286 neoplastic lesions, excluding 3 carcinoids, 137 were flat, 81 were sessile, 18 were large sessile, and 50 were semipedunculated. The 137 flat lesions consisted of 125 adenomas, 10 mucosal cancers, and 2 submucosal cancers. The rate of complete removal was related to their size and configuration and was 87 percent in flat neoplastic lesions. Lesion diameters of greater than 20 mm and the large sessile-type configurations were factors that were associated with incomplete removal. Two (0.7 percent) cases were complicated by perforations, and one (0.4 percent) case was complicated by bleeding. CONCLUSION: Endoscopic mucosal resection is an useful option for complete removal of colorectal nonpolypoid adenomas and cancers.     

Molecular karyotype (amplotype) of metastatic colorectal cancer by unbiased arbitrarily primed PCR DNA fingerprinting

Genomic instability characterizes the aneuploid cancer cell. Losses of genetic material are critical in cancer by exposing recessive mutations in tumor suppressor genes. Gains of genetic material also may lead to overexpression of genes contributing to tumor progression either in the presence or absence of mutation. However, the detection of moderate gains (such as tri-tetraploidy) has been a challenge in cancer research. Unbiased DNA fingerprinting by the arbitrarily primed PCR allows the detection of moderate gains (in addition to losses) of DNA sequences of known chromosomal localization. We have generated in this manner a molecular karyotype of metastatic colon cancer. This amplotype shows that sequences from several chromosomes undergo both losses (1, 4, 9, 14, and 18) and gains (6, 7, 12, and 20) in over half of the tumors. Moreover, gains of sequences from chromosomes 8 and 13 occurred in most tumors, indicating the existence in these chromosomes of positive regulators of cell growth or survival that are under strong positive selection during tumor progression. We conclude that overrepresentation of these chromosomal regions is a critical step for metastatic colorectal cancer. Comparative amplotype analysis from primary and metastatic tumors suggest the existence in chromosome 4 of gene(s) whose loss is specifically selected in cells that reach the metastatic stage.     

Chinese herbs and bone disease

We treated a patient with an unusual bone disease at least partly associated with Chinese herbs. Seven years after 65-year-old man had begun to consume Chinese herbs, multifocal osteoarthralgias were noted, and the patient was hospitalized for renal dysfunction (serum creatinine, 2.8 mg/dl; urea nitrogen, 19 mg/dl). Fanconi syndrome also was apparent. A renal biopsy specimen showed tubulo-interstitial fibrosis. Chinese herbs were discontinued and prednisolone was started, but bone and joint pain as well as renal function gradually worsened. Four years later, creatinine was 9.0 mg/dl and alkaline phosphatase was 571 IU/l. As bone scintigraphy revealed localized asymmetric lesions, Paget's disease of bone was suspected at first. However, neither osteosclerosis nor hypertrophy was seen in radiographs. Based on a bone specimen histology we diagnosed as mixed-type renal osteodystrophy including osteomalacia and osteitis fibrosa. Mosaic pattern of cement lines was not present. This case was not compatible with either Paget's disease or typical renal osteodystrophy as seen in dialysis patients. Etidronate disodium was effective in alleviating bone symptoms. The patient's bone disorder may be a new disease at least partly related to Chinese herbs independently of nephropathy.     

Ligation of CD44 leads to killing activity in human peripheral mononuclear cells via MAP kinase and tyrosine kinases

CD44 is a widely distributed transmembrane glycoprotein associated with various lymphocyte functions, including lympho-hemopoiesis, adhesion to the extracellular matrix, and T cell activation. In this study, we examined the mechanisms of CD44 involvement in regulating the killing activity of human peripheral mononuclear cells (PMC). An anti-CD44 monoclonal antibody (mAb) J173 enhanced the killing activity of PMC against Daudi and K562 cells in a dose-dependent manner. The increased cytotoxicity peaked at mAb concentration of 1.25 microg/ml. Under this condition, triggering of CD44 enhanced the killing activity by 1.5- and 2.2-fold at an effector-to-target (E/T) ratio of 20 for Daudi and K562 cells, respectively. Cytotoxic activity was remarkably diminished by treatment of PMC with concanamycin A, suggesting that this PMC-mediated cytotoxicity is mainly exerted via the perforin pathway. Moreover, we found that ligation of CD44 transduced signals to PMC that led to the tyrosine phosphorylation of several intracellular proteins and activation of mitogen-activated protein (MAP) kinase. Genistein, an inhibitor of tyrosine phosphorylation, and PD98059, an inhibitor of MAP kinase, suppressed CD44-induced enhancement of cytotoxicity. These results suggest that the CD44 molecule, which is a main receptor for hyaluronan known to be expressed on the surface of tumor cells, plays an important role in PMC-mediated cytotoxicity, and that tyrosine kinases and MAP kinase are essential for CD44-mediated signaling in cytotoxicity.     

Immunohistochemical detection of biotinlabeled murine monoclonal antibody in nude mice transplanted with human colon cancer

The tissue localization of biotin-labeled murine monoclonal antibody (MAb) A7 directed against human colonic cancer was examined in tumor-bearing nude mice following intravenous administration. MAb A7 did not react with any murine visceral organs. At 24 hr after biotin-labeled A7 injection, the tumor was stained by the avidin-biotin peroxidase complex method, but no staining was observed after injection of biotin-labeled normal mouse Ig G in the control group. Biotin-labeled MAb. was found to be suitable for the detection of the xenografted tumor of nude mice. Our purpose was to provide a new method concerning the distribution of biotin-labeled MAbin vivo. This study was supported in part by a Grant-in-Aid for Cancer Research from the Ministry of Education, Science and Culture, Japan, and by a grant from the Ministry of Health and Welfare, Japan.     

Enhanced production of interleukin-6 in mice with type II collagen-induced arthritis

We established an interleukin-6 (IL-6)-dependent cell line from murine plasmacytoma MOPC-104E cells. This cell line (designated PIL-6) was found to respond to murine and to human IL-6, but not to any other cytokines. We used this cell line to investigate the involvement of IL-6 production in type II collagen-induced arthritis in DBA/1 mice. Only marginal IL-6 activity was detected in sera from DBA/1 mice inoculated with Freund's complete adjuvant (FCA) alone, with an unrelated protein (bovine serum albumin) plus FCA, or with type II collagen plus Freund's incomplete adjuvant. However, enhanced IL-6 activity was observed in DBA/1 mice that had been injected with type II collagen plus FCA to induce arthritis. The elevated level of serum IL-6 activity was associated with high levels of IL-6 produced when lymph node cells from arthritic mice were stimulated in vitro with type II collagen. We also found that the L3T4+ T cell subset is responsible for the enhanced production of IL-6 in arthritic mice. The results are discussed in the context of potential roles of IL-6 in the induction and/or expression of chronic, progressive arthritis.     

Afterload mismatch in patients with hypertrophic nonobstructive cardiomyopathy

To investigate the cardiac reserve of hypertrophic nonobstructive cardiomyopathy (HNCM), an echocardiographic study was performed before and during angiotensin II loading in 22 HNCM patients without left ventricular (LV) systolic dysfunction at rest and 8 normal subjects. LV end-diastolic dimension (LVDd) and time velocity integral (Ie) at aortic annulus were obtained as parameters of preload and forward ejection respectively. Responses of these indices to afterload stress were compared with clinical findings and right ventricular biopsy findings. Based on the reserve of forward ejection characteristics to afterload stress, 22 HNCM patients were divided into 2 groups; Group I: 9 cases with more than 15% decrease of Ie which corresponded to the value of mean - 1SD in normal subjects, Group II: 13 cases with a decrease of Ie less than 15%. There were no significant differences in echocardiographic findings between Group I and II before angiotensin II loading. On the other hand, Group I had a smaller increase of LVDd (p less than 0.05) to afterload stress, a higher incidence of ventricular tachycardia on a Holter electrocardiogram (p less than 0.05), lower maximal oxygen consumption with treadmil exercise test (p less than 0.01), and a larger value of LV end-diastolic pressure (p less than 0.05) than those in Group II, respectively. Although no difference in myocyte diameter was found between the 2 groups, myocardial fibrosis was more severe (p less than 0.001) and the incidence of moderate or severe disarray was higher (p less than 0.05) in Group I than in Group II. Thus, some HNCM patients cannot maintain forward ejection to afterload stress because of impaired preload reserve attributable to a greater stiffness of the left ventricle with severe myocardial lesion.     

Small heat shock protein of Methanococcus jannaschii, a hyperthermophile

Small heat shock proteins (sHSPs) belong to a family of 12- to 43-kDa proteins that are ubiquitous and are conserved in amino acid sequence among all organisms. A sHSP homologue of Methanococcus jannaschii, a hyperthermophilic Archaeon, forms a homogeneous multimer comprised of 24 monomers with a molecular mass of 400 kDa in contrast to other sHSPs that show heterogeneous oligomeric complexes. Electron microscopy analysis revealed a spherically shaped oligomeric structure ≈15–20 nm in diameter. The protein confers thermal protection of other proteins in vitro as found in other sHSPs. Escherichia coli cell extracts containing the protein were protected from heat-denatured precipitation when heated up to 100°C, whereas extracts from cells not expressing the protein were heat-sensitive at 60°C. Similar results were obtained when purified sHSP protein was added to an E. coli cell lysate. The protein also prevented the aggregation of two purified proteins: single-chain monellin (SCM) at 80°C and citrate synthase at 40°C.     

Isolation and characterization of a mouse cDNA clone that expresses mast-cell growth-factor activity in monkey cells.

A cDNA sequence coding for mouse mast-cell growth-factor (MCGF) has been cloned from a cDNA library prepared from mRNA derived from a concanavalin A-activated mouse T-cell clone. Cloning was achieved using the pcD vector that permits expression of cDNA inserts in mammalian cells. The DNA sequence codes for a polypeptide of 166 amino acid residues including a putative signal peptide. The supernatant fluid obtained after transfection of COS-7 monkey cells with the pcD-MCGF plasmid had mouse MCGF activity. The MCGF amino acid sequence between amino acids 33 and 41, deduced from the nucleotide sequence of its cDNA, is identical to the NH2-terminal sequence of the mouse lymphokine, interleukin 3, suggesting that MCGF is related to interleukin 3.