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Biomedical subjects

M Yoshihara

Publications and source records attributed to M Yoshihara.

At least 37 records · Page 2Linked to original sources

Microsatellite instability is a genetic marker for the development of multiple gastric cancers.

Multiple gastric cancers are found in 5-15% of all patients with gastric cancer. However, no molecular markers have yet been shown to be clinically useful for predicting which patient will or will not have multiple gastric cancers. Recently, microsatellite instability (MSI) has been identified as a molecular marker for multiple colorectal cancers. To elucidate whether MSI could be used as a molecular marker for multiple gastric cancers, we examined MSI in 38 patients with a single gastric cancer, in 26 patients with synchronous multiple gastric cancers and in 14 patients with metachronous multiple gastric cancers. In the patients with synchronous multiple gastric cancers, 1 of the larger tumors was examined. In the patients with metachronous multiple gastric cancers, the first gastric cancer was examined. Five microsatellite loci, including D17S855, D18S58, D18S61, BAT25 and BAT40, were examined with microsatellite assay. MSI was divided into low frequency of MSI (MSI-L) and high frequency of MSI (MSI-H) by the number of affected loci. MSI-L was detected in 3 of the 38 (8%) patients with a single gastric cancer, in 7 of the 26 (27%) patients with synchronous multiple gastric cancers and in 6 of the 14 (43%) patients with metachronous multiple gastric cancers. MSI-H was detected only in 1 of the 38 (3%) patients with a single gastric cancer. The frequency of MSI-L was significantly higher in patients with multiple gastric cancers, both synchronous and metachronous, than in those with a single gastric cancer (p < 0.05 and p < 0.01, respectively). Patients with MSI(+) gastric cancer developed a significantly higher frequency of secondary gastric cancer, when compared with patients with MSI(-) gastric cancer (p < 0.05). These data suggest that MSI may play an important role in the development of multiple gastric cancers, and it may be used clinically as a molecular marker for the prediction of multiple gastric cancers.

Colorectal Neoplasms↗

Clinicopathological significance of vascular endothelial growth factor (VEGF)-C in human esophageal squamous cell carcinomas.

The purpose of this study was to investigate the expression of vascular endothelial growth factor (VEGF) -C in human esophageal squamous cell carcinomas to elucidate its role in lymph node metastasis and tumor progression. The expression of VEGF-C and flt-4 genes was examined in 5 esophageal carcinoma cell lines, 12 fresh biopsy specimens and 48 archival surgical specimens of human esophageal carcinoma tissues by RT-PCR and immunohistochemistry. Immunohistochemistry using antibodies against CD34 (endothelial cell specific) was also carried out and microvessels were quantified by counting vessels in a 200x field in the most vascular area of the tumor. Of the 5 human esophageal carcinoma cell lines, 4 constitutively expressed VEGF-C mRNA. In 8 (66.7%) of 12 cases, VEGF-C mRNA was detected in only tumor tissues but not in normal mucosa by RT-PCR. There was a significant relationship between VEGF-C and flt-4 mRNA expression. Out of the 48 surgical specimens of esophageal carcinomas, 19 (39.6%) and 10 (20.8%) exhibited intense VEGF-C immunoreactivity in the cytoplasm of many cancer cells and the stromal cells, respectively. In contrast, Flt-4 was mainly expressed on the lymphatic endothelial cells. Normal and dysplastic esophageal squamous epithelium exhibited no or faint cytoplasmic staining of VEGF-C. VEGF-C expression correlated with depth of tumor invasion, tumor stage, venous invasion, lymphatic invasion and lymph node metastasis. Vessel count was significantly higher in the VEGF-C positive tumors than in the negative tumors. These results overall suggest that VEGF-C may play a role in tumor progression via lymphangiogenesis and angiogenesis in human esophageal carcinoma.

Carcinoma, Squamous Cell↗

Establishment and characterization of a human B cell line from the lung tissue of a patient with scleroderma; extraordinary high level of IL-6 secretion by stimulated fibroblasts.

Progressive systemic sclerosis is a connective tissue disease of unknown aetiology. This is the first study to demonstrate induction by a human B cell line of IL-6 secretion from fibroblasts. The cell line was established from lesional lung tissue of a patient with progressive systemic sclerosis. These cells, referred to as kon-1 cells, showed characteristics of pro-B cell by flow cytometry. Although kon-1 cells alone secreted a small amount of IL-6, a co-culture of kon-1 cells with normal lung fibroblasts significantly increased IL-6 levels. Whereas IL-6 mRNA was weakly expressed in kon-1 cells alone, it was clearly expressed in cells from the co-culture. Immunocytochemical identification of IL-6 showed localization in the cytoplasm of fibroblasts. IL-6 is a pleiotropic cytokine, essential for B cell differentiation, which has been shown to stimulate the production of collagen and glycosaminoglycan. Thus, abnormally augmented B cell proliferation and the inflammatory response stimulated by these cells may cause the fibrotic changes in patients with progressive systemic sclerosis.

B-Lymphocytes↗

Cepharanthine activates caspases and induces apoptosis in Jurkat and K562 human leukemia cell lines.

Cepharanthine (CEP) is a known membrane stabilizer that has been widely used in Japan for the treatment of several disorders such as anticancer therapy-provoked leukopenia. We here report that apoptosis was induced by low concentrations (1-5 microM) of CEP in a human leukemia T cell line, Jurkat, and by slightly higher concentrations (5-10 microM) in a human chronic myelogenous leukemia (CML) cell line K562, which expresses a p210 antiapoptotic Bcr-Abl fusion protein. Induction of apoptosis was confirmed in both Jurkat and K562 cells by DNA fragmentation and typical apoptotic nuclear change, which were preceded by disruption of mitochondrial membrane potential and were induced through a Fas-independent pathway. CEP treatment induced activation of caspase-9 and -3 accompanied by cleavage of PARP, Bid, lamin B1, and DFF45/ICAD in both Jurkat and K562 cells, whereas caspase-8 activation and Akt cleavage were observed only in Jurkat cells. The CEP-induced apoptosis was completely blocked by zVAD-fmk, a broad caspase inhibitor. Interestingly, CEP treatment induced remarkable degradation of the Bcr-Abl protein in K562 cells, and this degradation was prevented partially by zVAD-fmk. When used in combination with a nontoxic concentration of herbimycin A, lower concentrations (2-5 microM) of CEP induced obvious apoptosis in K562 cells with rapid degradation or decrease in the amount of Bcr-Abl and Akt proteins. Our results suggest that CEP, which does not have bone marrow toxicity, may possess therapeutic potential against human leukemias, including CML, which is resistant to anticancer drugs and radiotherapy.

Alkaloids↗

Angiogenesis at the site of deepest penetration predicts lymph node metastasis of submucosal colorectal cancer.

PURPOSE: Intratumor microvessel count has been reported as a useful prognostic factor in patients with cancer of various organs. This study was undertaken to clarify the relation between microvessel count and lymph node metastasis in submucosal colorectal cancer. METHODS: Microvessel count was estimated in 254 invasive tumors that had been resected from patients with submucosal colorectal cancer. Immunohistochemistry with antibodies against CD34 was performed on archival specimens, and microvessel counts were estimated based on the average count of three fields (original magnification, x400) in the most vascular area at the site of deepest submucosal penetration. RESULTS: Microvessel count ranged from 10 to 98, with a median of 40. Lesions with high microvessel counts (> or =40) had a significantly higher incidence of lymph node metastasis than those with low microvessel counts (<40; 21.8 percent vs. 6.2 percent). None of the 79 lesions with low microvessel counts and submucosal invasion up to a depth of 1,500 microm had metastasized to the lymph nodes. In multivariate analysis, microvessel count was an independent risk factor for lymph node metastasis in submucosal colorectal cancer (P = 0.0026). CONCLUSION: Microvessel count at the site of deepest submucosal penetration can be one of the most useful predictors for lymph node metastasis. Analysis that combines microvessel count and depth of submucosal invasion may predict the occurrence of lesions without lymph node metastasis.

Adenocarcinoma↗

B-cell monoclonality in Helicobacter pylori-associated chronic atrophic gastritis.

B-cell monoclonality has been reported not only in gastric lymphoma, but also in 1.3-21% of Helicobacter pylori-associated chronic gastritis (Hp-CG) cases. The aim of this study was to determine the significance of B-cell monoclonality in Hp-CG. We examined 134 gastric biopsy specimens from 99 patients with Hp-CG. The density of Hp, polymorphonuclear neutrophil activity, chronic inflammation, glandular atrophy, and intestinal metaplasia (IM) were scored according to the updated Sydney System. B-cell monoclonality was analyzed for immunoglobulin heavy chain gene rearrangement using polymerase chain reaction amplification. B-cell monoclonality was detected in 6% of informative samples. B-cell monoclonality was found in 18% of the samples from Hp-CG patients with marked glandular atrophy but in none of the samples from Hp-CG patients with none to moderate glandular atrophy. Monoclonality was also detected in 20% of the samples from Hp-CG patients with marked IM, in 11% of the samples from Hp-CG patients with moderate IM, and in none of the samples from Hp-CG patients without IM. Therefore, B-cell monoclonality was significantly more frequent in Hp-CG patients with marked glandular atrophy than in Hp-CG patients with none to moderate atrophy. It was also more significantly frequent in Hp-CG patients with moderate or marked IM than in Hp-CG patients without IM (P < 0.05). Of 35 Hp-CG patients, 26 (74%) had identical B-cell populations in the antrum and the corpus, and all were polyclonal. The remaining nine (26%) Hp-CG patients had B-cell populations that differed in the antrum and the corpus. Four of the nine (44%) showed monoclonal B-cell populations in at least one gastric biopsy specimen. There were no patients with monoclonal B-cell populations in both the antrum and the corpus. These data suggest that glandular atrophy and IM in gastric biopsy specimens may be markers for gastric mucosa-associated lymphoid tissue (MALT) lymphoma-genesis and that multiple gastric biopsy specimens from both the antrum and the corpus may be needed to assess the risk of gastric MALT lymphoma.

B-Lymphocytes↗

A low 13C-urea breath test value is associated with increased risk of gastric cancer.

PURPOSE: The 13C-urea breath test (UBT) is considered to be the most accurate way of diagnosing Helicobacter pylori infection. Values are affected by H. pylori infection and by the severity of atrophic gastritis. Our objective was to determine the association of UBT values with gastric cancer, and to evaluate the risk of gastric cancer in terms of UBT values. METHODS: Our study involved 413 consecutive patients who had undergone esophagogastroduodenal examination and the UBT test. RESULTS: Of the 398 patients with positive UBT results, atrophy and intestinal metaplasia scores in both antrum and corpus were significantly higher in patients with gastric cancer than in those with gastritis, duodenal ulcer, and gastric ulcer. The UBT value related to gastric cancer (22.01 +/- 1.89%o) was significantly lower than that for gastritis (35.19 +/- 1.53%o; P < 0.01), duodenal ulcer (29.01 +/- 1.97%; P < 0.05), or gastric ulcer (30.79 +/- 2.83%; P < 0.05). When the UBT values were less than 20%, increases in the risk of gastric cancer correlated with decreasing UBT values. CONCLUSIONS; These findings indicate that the UBT value related to gastric cancer is significantly lower than that for gastritis, duodenal ulcer, or gastric ulcer in H. pylori-positive patients. Low UBT values were associated with the risk of gastric cancer.

Biopsy↗

Neurobiology and the Drosophila genome.

The sequencing and annotation of the euchromatin of the Drosophila melanogaster genome provides an important foundation that allows neurobiologists to work back from the complete gene set of neuronal proteins to an eventual understanding of how they function to produce cognition and behavior. Here we provide a brief survey of some of the key insights that have emerged from analyzing the complete gene set in Drosophila. Not surprisingly, both the Caenorhabditis elegans and Drosophila genomes contain a conserved repertoire of neuronal signaling proteins that are also present in mammals. This includes a large number of neuronal cell adhesion receptors, synapse-organizing proteins, ion channels and neurotransmitter receptors, and synaptic vesicle-trafficking proteins. In addition, there are a significant number of fly homologs of human neurological disease loci, suggesting that Drosophila is likely to be an important disease model for human neuropathology in the near future. The experimental analysis of the Drosophila neuronal gene set will provide important insights into how the nervous system functions at the cellular level, allowing the field to integrate this information into the framework of ultimately understanding how neuronal ensembles mediate cognition and behavior.

Animals↗

Cathepsin D expression as a possible predictor of lymph node metastasis in submucosal colorectal cancer.

The aim of this study was to clarify the usefulness of cathepsin D expression as a predictor of lymph node metastasis in submucosal colorectal cancer (CRC). Cathepsin D expression was examined immunohistochemically in cancer and stromal cells located at the deepest portion of 254 invasive tumours that had been resected from patients with submucosal CRC. In cancer cells, the expression was classified according to differences in intracellular localisation: polarity positive, apical type (PA); polarity positive, basal type (PB); polarity negative (PN); or no expression (NE). Lesions with PN or NE expression showed a significantly higher incidence of lymph node metastasis than those with PA or PB expression. Alternatively, lesions with positive expression in stromal cells showed a significantly higher incidence of lymph node metastasis than that of those with negative expression. None of the lesions with PA or PB expression and negative expression in stromal cells had metastasised to the lymph node. In conclusion, analysis combining cathepsin D expression in cancer and stromal cells may be a quite useful predictor for lymph node metastasis and may broaden the indications for curative endoscopic treatment of submucosal CRC.

Analysis of Variance↗

Interleukin 8 and vascular endothelial growth factor -- prognostic factors in human gastric carcinomas?

Gastric carcinoma cells express potent angiogenic factors including vascular endothelial growth factor (VEGF). We previously reported that interleukin-8 (IL-8) acts as an angiogenic factor for human gastric carcinomas. More recently, we found that IL-8 upregulates matrix metalloproteinase-9 (MMP-9) expression and increases invasive activity of gastric carcinoma cells. The purpose of this study was to determine whether the expression of IL-8 and VEGF correlates with clinicopathological parameters in human gastric carcinomas. IL-8 and VEGF expression levels were measured by an enzyme-linked immunosorbent assay (ELISA) in 56 gastric carcinomas and the surrounding normal mucosa. Macroscopic and histopathological tumour findings, presence of metastasis and prognosis were obtained from the patient records and endoscopic, surgical and pathological reports. IL-8 protein levels were higher in most neoplasms than in the corresponding normal mucosal tissue. In contrast, VEGF expression in the tumours was similar to that in normal mucosa. The IL-8 level in the neoplasms correlated significantly with the depth of invasion, venous invasion and lymphatic invasion. VEGF expression in the tumours correlated well with the depth of invasion and lymph node metastasis. No correlation between IL-8 and VEGF expression in the tumours was observed. The survival rates of patients with tumours displaying high IL-8 and VEGF expression levels were significantly lower (P<0.05) than those of patients with tumours displaying low IL-8 and VEGF expression. The results suggest that IL-8 and VEGF may be independent and important prognostic factors in human gastric carcinomas.

Adult↗

Clinicopathological features of gastric mucosa-associated lymphoid tissue lymphoma: a comparison with diffuse large B-cell lymphoma without a mucosa-associated lymphoid tissue lymphoma component.

BACKGROUND AND AIMS: The aim of this study was to clinicopathologically distinguish the pathogenesis of gastric mucosa-associated lymphoid tissue (MALT) lymphoma and diffuse large B-cell lymphoma without a MALT lymphoma component (DLL). METHODS: We investigated clinicopathological features of these gastric lymphomas including age, sex ratio, tumor location and depth, macroscopic appearance, and infection with Helicobacter pylori of these gastric lymphomas and hepatitis viruses in 24 patients with gastric low-grade MALT lymphoma, 10 patients with high-grade MALT lymphoma, and 19 patients with DLL. The frequency of H. pylori infection in lymphoma patients was compared with that in age- and sex-matched control subjects. RESULTS: There was a predominance of females with MALT lymphoma (male to female ratio, 8/16 for low-grade MALT lymphomas and 1/9 for high-grade MALT lymphomas), and there was a predominance of males with DLL (male to female ratio, 13/6); the ratios differed significantly (P < 0.05). Ninety-two percent of low-grade MALT lymphomas and 80% of high-grade MALT lymphomas were confined to the mucosal and submucosal layers, but lymphoma cells invaded the muscular layer or more deeply in 74% of DLL. Helicobacter pylori infection occurred significantly more often in patients with low-grade MALT lymphoma than in age- and sex-matched controls (96 vs 67%, P < 0.01). Conversely, the frequency of H. pylori infection in DLL patients did not differ from that in controls. CONCLUSIONS: These data suggest that H. pylori infection may be associated with the development of gastric MALT lymphoma, but not DLL, and that MALT lymphoma and DLL may have a different pathogenesis.

Adult↗

Duodenogastric reflux is associated with antral metaplastic gastritis.

BACKGROUND: It has long been suspected that duodenogastric reflux plays a role in the pathogenesis of intestinal metaplasia (IM), although recent studies have demonstrated a close association between Helicobacter pylori infection and gastroduodenal diseases, including IM. The objective of this study was to investigate the relation among IM and duodenogastric reflux, H pylori infection, and smoking. METHODS: Subjects with "marked" characteristics of IM, all with extensive prepyloric distribution at endoscopy that was confirmed histologically, were studied as an IM group (27 men, 26 women; mean age, 64 years). A control group was comprised by subjects without characteristics of IM (29 men, 28 women; mean age, 63 years). Fasting pH, total bile acid concentration, and ammonia concentration were measured in the gastric juice of all participants. Histologic examination endoscopic biopsy specimens were evaluated histologically. H pylori infection was determined by serum antibody and urease testing, and by histology. Serum gastrin and pepsinogen concentrations, and gastric emptying time were measured. Dietary, drinking, and smoking habits were recorded. Comparisons were made between groups and analyzed statistically. RESULTS: The pH and total bile acid concentrations were significantly higher in the IM group than the control group (p < 0.01). No significant difference in H pylori infection was found between the IM and control group. Smoking was associated with IM (odds ratio [OR], 15.74; 95% CI, 3.96 to 62.50). CONCLUSIONS: A high pH and total bile acid concentration and smoking were associated with "marked" IM, suggesting that these factors may play a role in the development of IM.

Duodenogastric Reflux↗

Clinicopathologic features and endoscopic treatment of superficially spreading colorectal neoplasms larger than 20 mm.

BACKGROUND: A colorectal neoplasm that spreads superficially over the mucosa is known as a laterally spreading tumor. The clinicopathologic features of these large lesions and the efficacy and safety of endoscopic mucosal resection (EMR) were studied retrospectively. METHODS: Surgically or endoscopically resected laterally spreading tumors larger than 20 mm in diameter were studied. Lesions were divided into 2 macroscopic subtypes: F-type, composed of superficially spreading lesions with a flat and smooth surface, and G-type, composed of superficially spreading aggregates of nodules that form relatively flat, broad-based lesions with granulonodular and uneven surfaces. RESULTS: Thirty-three lesions were of the F-type and 87 the G-type. G-type (mean +/- SD, 35.3 +/- 11.4 mm) lesions were significantly larger (p < 0.01) than F-type (26.0 +/- 7.2 mm) lesions. F-type lesions had a significantly higher frequency of invasive cancer (27.2%) than G-types (10.3%)(p < 0.05). Of the 120 lesions, 81 (67.5%) were resected endoscopically. Patients with 78 of these lesions were followed postoperatively for 60.8 +/- 20.1 months. The rate of local recurrence of endoscopically treated tumors as determined at colonoscopy was 7.4% (6/78). These lesions were completely resected endoscopically. Distant metastases were not detected. Thirteen (16.0%) patients had local bleeding after EMR that was stopped endoscopically. Microperforation of the colonic wall as a result of EMR was diagnosed in 1 (1.2%) of 81 cases. CONCLUSIONS: Laterally spreading tumors larger than 20 mm, especially those of the G-type, have a low rate of invasion despite their relatively large size. The F-type lesion has a higher malignant potential than the G-type. EMR is an effective and safe treatment for the large laterally spreading tumor.

Adenoma↗

Clinical significance of human erythrocyte glucose transporter 1 expression at the deepest invasive site of advanced colorectal carcinoma.

OBJECTIVE: Malignant cells exhibit increased glucose uptake and utilization in vitro and in vivo. This process is thought to be mediated by the glucose transporter (Glut) family. The aim of this study was to elucidate the clinical significance of Glut1 expression at the site of deepest invasion as a predictor of the invasive/metastatic potential and prognosis of advanced colorectal carcinoma (CRC). METHODS: One hundred and fifty-two patients who had undergone surgical resection for advanced CRC were entered in this study. Histologic subclassifications at the deepest invasive site included well-differentiated (W), moderately to well-differentiated (Mw), moderately to poorly differentiated (Mp), poorly differentiated (Por) and mucinous (Muc) adenocarcinomas. Glut1 expression was examined immunohistochemically with a labeled streptavidin-biotin kit using anti-Glut1 polyclonal antibody MYM. As a marker of cell proliferation, Ki-67 expression was also examined. All immunoreactivity was analyzed at the deepest invasive site, central portion and superficial part. The immunohistochemical expression of Glut1 was defined as positive if distinct staining of the membrane or cytoplasm was observed in at least 30% of tumor cells. RESULTS: Glut1 expression was detected in 56 of 152 lesions (36.8%) at the deepest invasive site. The incidence of Glut1 expression at the deepest invasive site correlated significantly with histologic grade (W/Mw grade, 28% vs. Mp/Por/Muc grade, 48%), depth of invasion (invasion of muscularis propria/invasion of subserosa or subadventitia, 29% vs. invasion of serosa or adventitia/invasion of adjacent structures, 52%), lymphatic invasion (absence of lymphatic invasion, 19% vs. presence of lymphatic invasion, 40%), lymph node metastasis (absence of lymph node metastasis, 25% vs. presence of lymph node metastasis, 41%) and Duke's stage (Duke's <D, 32% vs. Duke's D, 51%). In the central portion and superficial part, there were no significant differences between Glut1, Ki-67 expression and clinicopathological findings. Glut1 expression at the deepest invasive site correlated significantly with the Ki-67 labeling index. In cases of curative surgery, patients with Glut1-positive lesions at the deepest invasive site showed a significantly poorer prognosis than those with Glut1-negative lesions. Multivariate analysis with logistic regression for 5-year survival in patients who had undergone curative surgery showed that lymph node metastasis and Glut1 expression were significant risk factors. CONCLUSION: These results indicate that Glut1 expression at the deepest site of tumor invasion can be a useful predictor of a high malignant potential and poor prognosis in advanced CRC.

Adenocarcinoma↗

Helicobacter pylori eradication therapy for high-grade mucosa-associated lymphoid tissue lymphomas of the stomach with analysis of p53 and K-ras alteration and microsatellite instability.

Recent studies have shown that 70-80% of low-grade mucosa-associated lymphoid tissue (MALT) lymphomas regress in response to eradication of Helicobacter pylori (H. pylori). However, there are no reports on whether gastric high-grade MALT lymphomas regress after H. pylori eradication. We performed H. pylori eradication therapy in 4 patients with stage I, high-grade MALT lymphoma after obtaining their informed consent. H. pylori infection was observed in all 4 patients. The patients were treated with proton-pump inhibitor-based eradication therapy for 1 or 2 weeks, and then underwent endoscopic examination and biopsy sampling. H. pylori eradication was achieved in all 4 patients. Six months after eradication treatment, 2 patients showed complete regression of the lymphoma and 2 patients showed no change. The 2 patients with non-responding lymphoma were then treated with an additional chemotherapy (CHOP regimen), whereupon the tumors completely regressed. These patients, followed-up at least 18 months after eradication treatment, showed no recurrence. We also examined genetic alteration of the p53 and K-ras genes and microsatellite instability in these high-grade MALT lymphomas. One patient with a tumor that showed no change after H. pylori eradication, had a loss of heterozygosity of the p53 gene. No other genetic alterations were detected among the patients. Our results indicate that the eradication of H. pylori may be effective not only for patients with low-grade MALT lymphoma but also for patients with high-grade MALT lymphoma. The treatment may be efficacious as a first-line therapy for patients with high-grade MALT lymphoma. However, our sample size was limited and further studies are needed to clarify the issue.

Aged↗

MUC1 and cathepsin D expression in early colorectal carcinoma showing V type pit pattern.

The relation between MUC1, cathepsin D expression, and histologic features in early colorectal carcinomas (CRCs) with V type pit pattern was examined in 78 patients. We classified V type pit pattern into two grades (VA, VN) and we subclassified the VN type pit pattern into three subtypes (Grade A, B, and C) according to the degree of appearance of VN type pit pattern. At the tumor surface, the status of desmoplastic reaction and pit disorder or destruction were subclassified histologically into three grades (-, +, ++). MUC1 and cathepsin D expression were examined immunohistochemically at a superficial level and at the deepest part of the tumor invasion. MUC1 expression showed a significant correlation with high grade carcinoma, desmoplastic reaction (+) levels in VA type pit pattern (P<0.05), and high grade carcinoma, sm2 and sm3 lesions, desmoplastic reaction (+) and (++) levels, pit disorder or destruction (+) and (++) levels in VN type pit pattern (P<0.05). Cathepsin D expression had a significant correlation with m and sm1 lesions and desmoplastic reaction (-) levels in VN type pit pattern (P<0.05). In VA type pit pattern, a significant correlation between cathepsin D expression and histologic findings was absent. The incidence of MUC1 expression in VN.Grade B and C type pit pattern was significantly higher than that in VA and VN.Grade A type pit pattern (P<0.05). The incidence of cathepsin D expression in VA, VN.Grade A and B type pit pattern was significantly higher than that in VN.Grade C type pit pattern (P<0.05). MUC1 expression (+) or (++) levels at the deepest part of a tumor was identical to that (+) or (++) levels at the superficial part except for one case. Cathepsin D expression at the deepest part of a tumor differed from that at the superficial part. Desmoplastic reaction may be related to MUC1 and cathepsin D expression; however, pit disorder or destruction may be related to only MUC1 expression in V type pit pattern. MUC1 expression at the superficial part of a tumor may be related to expression at the deepest part; however, cathepsin D expression at the superficial part may not be related to expression at the deepest part in submucosal CRCs with V type lesions.

Cathepsin D↗

Screening for synaptic defects revealed a locus involved in presynaptic and postsynaptic functions in Drosophila embryos.

To identify genes involved in synaptic functions, we screened lethal enhancer trap lines by monitoring synaptic activities at the neuromuscular junction in Drosophila embryos. It was found that MY7919, thus isolated, has moderate defects in both pre- and postsynaptic functions. The mean amplitudes of spontaneous as well as evoked synaptic currents were smaller than those in wild-type. The failure rate was higher than normal at any given concentration of external Ca(2+), indicating that presynaptic functions were impaired. In addition, the mean amplitude of miniature synaptic currents was smaller, and the unitary current amplitudes of junctional glutamate receptor channels were slightly but significantly smaller. Thus, postsynaptic functions were also altered. The gene was cloned and found to be identical to the previously reported apontic (=tracheae defective) locus, which is believed to be a transcription factor expressed in the central nervous system (CNS) as well as in the head, tracheae, and heart. Immunohistochemical analysis using an antiapontic antibody revealed that the protein is localized to nuclei. Null alleles of the apontic locus were obtained by imprecise excision of the enhancer trap vector. Synaptic activities in null mutants were not different from those of the original allele, even though null homozygotes had uncontracted ventral nerve cords and more severe behavioral phenotypes. The morphology of the neuromuscular junction of the null mutant was qualitatively similar to that of wild-type, with the presence of typical pre- and postsynaptic specializations, but with some suggestions of quantitative differences. This strategy for screening mutants with synaptic defects will reveal more genes directly or indirectly affecting synaptic transmission.

Amino Acid Sequence↗