Search PubMed⌕ Search

Biomedical subjects

T Muto

Publications and source records attributed to T Muto.

At least 37 records · Page 2Linked to original sources

Superficial depressed early carcinoma that developed into protuberant advanced carcinoma in the transverse colon.

A screening colonoscopic examination in a 70-year-old man revealed a nonpolypoid type superficial depressed early carcinoma, about 2cm in diameter, in the transverse colon. The lesion was not resected and was observed because of coexisting nonresectable hepatocellular carcinoma (HCC). Fifteen months later, follow-up examinations revealed a polypoid type protuberant advanced carcinoma, about 6 cm in diameter, at the same site. Because complete response of the HCC had been induced by transarterial embolization, the colon carcinoma was operatively resected. There is an indefinite concept that colorectal carcinomas develop without substantial morphological changes, and no superficial depressed carcinoma that developed into a protuberant type advanced carcinoma has been reported. The case reported here provides evidence that some polypoid carcinomas arise from superficial depressed precursors. There is some intermingling between the two postulated colorectal carcinogenic pathways, the conventional polypoid pathway named the "adenoma-carcinoma sequence", and the nonpolypoid pathway, including so-called "de-novo" carcinogenesis.

Aged↗

Infected abdominal aortic aneurysm presenting with sudden appearance: diagnostic importance of serial computed tomography.

The case of an 86-year-old man with an infected abdominal aortic aneurysm (AAA) that developed suddenly over 3 weeks is presented here. Previous reports on the diagnosis of infected AAA have focused mainly on the findings of single computed tomography (CT). These include the presence of a saccular aneurysm with an irregular lumen, perianeurysmal fluid, gas and/or hematoma, osteomyelitis in adjacent vertebral bodies, disruption of intimal calcification, and obscuring of the aortic wall. Our case report presents a useful diagnostic technique for the diagnosis of infected AAA, emphasizing the importance of serial CT for suspected cases, even if the initial scan does not demonstrate the findings listed above.

Aged↗

Associations of distinct variants of the intestinal mucin gene MUC3A with ulcerative colitis and Crohn's disease.

Ulcerative colitis (UC) and Crohn's disease (CD), the major forms of inflammatory bowel diseases (IBDs). are multifactorial disorders of unknown etiology. We reported a possible association of rare variable number of tandem repeat (VNTR) alleles of the "MUC3" gene with a susceptibility to UC. However, an entire structure of "MUC3" is still unknown because the long stretches of tandem repeats in this "gene" make its cloning extraordinarily difficult. In this study, we report evidence that "MUC3" consists of two genes, MUC3A and MUC3B, both of which encode membrane-bound mucins with two epidermal growth factor-like motifs, and we describe the complete 3'-terminal structures of these two genes. We have also analyzed the single nucleotide polymorphisms (SNPs) in the exonic sequences of the 3' portions of these two genes to investigate whether sequence variations in these regions can cause person-to-person differences in the susceptibility to IBDs, and report here that non-synonymous SNPs of MUC3A, involving a tyrosine residue with a proposed role in cell signaling, may confer genetic predisposition to CD (P = 0.0132). Our findings suggest that variants of MUC3A may be involved in the occurrence of UC and CD in distinct manners.

Amino Acid Sequence↗

The indication of local excision for T2 rectal carcinomas.

BACKGROUND: Several researchers reported that local excision with or without postoperative chemo-radiation therapy is an alternative approach for sphincter preservation in patients with locally invasive rectal carcinoma. However, indications and long-term results have not yet been determined. METHODS: Seventy-two patients with T2 colorectal carcinomas underwent bowel resection with regional lymph node dissection. The associations between lymph node metastasis (LNM) and clinicopathologic factors were examined with special reference to the presence or absence of moderate to severe degree of focal dedifferentiation or mucinous component at the invasive margin (unfavorable histology). RESULTS: Multivariate logistic regression analysis revealed that both sex and unfavorable histology were significantly associated with LNM (P = 0.0102, 0.0226, respectively). However, the associations between LNM and lymphatic invasion or tumor location were not statistically significant (P = 0.0947, 0.1738). CONCLUSIONS: When locally resected T2 rectal carcinoma specimens have unfavorable histology at the invasive margin, additional bowel resection with lymph node dissection should be recommended.

Colorectal Neoplasms↗

Anatomical major resection versus nonanatomical limited resection for liver metastases from colorectal carcinoma.

BACKGROUND: Although systematic anatomical hepatic resection has been reported to improve patient survival in hepatocellular carcinoma, principles of hepatectomy procedure have not been clearly demonstrated in secondary hepatic malignancy. The purpose of the present study was to determine whether selection of surgical procedures for liver resection is associated with the pattern of tumor recurrence or patient survival. METHODS: During the period of 1980 through 1999, 174 cases underwent liver resection for hepatic metastasis from colorectal cancer. Of these, 96 underwent systematic anatomical major hepatic resection (anatomical group) and 78 cases underwent nonanatomical limited resection (nonanatomical group). Subset analysis of 115 patients with unilobar single or double tumors was also conducted. RESULTS: The overall 5-year survival rate of 174 patients was 43.2%. Univariate analysis did not show a significant difference in patient survival according to surgical procedure (anatomical group versus nonanatomical group). Operative morbidity and mortality rates were slightly higher in anatomical group. From the subset analysis in unilobar single or double tumors, anatomical major hepatectomy was unnecessary in 80.4% of the cases if the tumors were resectable by nonanatomical limited resection. Ninety percent of the ipsilateral recurrence, which could have been avoided if the first operation was anatomical hemihepatectomy, could undergo second hepatectomy with 5-year survival rate of 58.3%. CONCLUSIONS: There was not a significant difference in patient survival according to surgical procedure. To minimize surgical stress and operative risk, nonanatomical limited liver resection should be a basic surgical procedure for colorectal metastases.

Colorectal Neoplasms↗

Proliferative activity of intrahepatic colorectal metastases after preoperative hemihepatic portal vein embolization.

Although hemihepatic portal vein embolization (PVE) has been used preoperatively to extend indications for hepatectomy in patients with colorectal metastases, the effects of this procedure on tumor growth and outcome remain controversial. To address this issue, we assessed the proliferative activity of intrahepatic metastases after PVE and the long-term outcome of this procedure. Eighteen patients with colorectal metastases underwent preoperative PVE between 1996 and 2000 (PVE group). Twenty-nine patients who underwent major hepatic resection without PVE served as control (non-PVE group). The hepatic parenchymal fraction of the left lobe had significantly increased from 38.1 +/- 3.2% to 45.9 +/- 2.9% 3 weeks after PVE (+20.5%, P <.0001). Tumor volume and percent tumor volume had also significantly increased from 223 +/- 89 mL to 270 +/- 97 mL (+20.8%, P =.016) and from 13.7 + 4.3% to 16.2 + 4.9% (+18.5%, P =.014), respectively. There was no apparent correlation between the increase in parenchymal volume and that in tumor volume. The Ki-67 labeling index of metastatic lesions was 46.6 +/- 7.2% in the PVE group and 35.4 +/- 12.6% in the non-PVE group (P =.013). Long-term survival was similar in the PVE and non-PVE groups, however, disease-free survival was significantly poorer in the PVE group than in the non-PVE group (P =.004). We conclude that PVE increases tumor growth and probably is associated with enhanced recurrence of disease. Although PVE is effective in extending indications for surgery, patient selection for PVE should be cautious.

Adult↗

Immunohistochemical localization of membrane type 1-matrix metalloproteinase (MT1-MMP) in osteoclasts in vivo.

Membrane type 1-matrix metalloproteinase (MT1-MMP) is capable of mediating proteolysis of extracellular matrix. The enzyme has been demonstrated in osteoclasts, in vitro. However, the precise localization in vivo, and therefore the function of the enzyme in osteoclasts, is still unclear. In this study, we immunohistochemically examined the localization of MT1-MMP in rat osteoclasts to clarify the role of MT1-MMP in osteoclastic bone resorption and bone turnover. The localization of MT1-MMP was visualized by the pre-embedding method using anti-MT1-MMP antibody and horseradish peroxidase (HRP) or gold-conjugated antibody. Immunoreactivity of anti-MT1-MMP was found in osteoclasts at the osteoclast-bone interface, but it was not uniform. Ultrastructurally, the immunoreactivity visualized by HRP was found in sealing zone. The plasma membrane at this site showed an irregular border and some invaginations. Immunoreactivity was also found on the surface of certain small vesicles in the cytoplasm. Enhanced silver granules were mainly associated with the sealing membrane. In this study, we demonstrated, for the first time, the localization of MT1-MMP in the sealing zone of osteoclast in vivo. Its distribution suggests that the enzyme modifies the bone surface to facilitate the migration and attachment of osteoclasts as well as scavenging the resorption lacunae.

Animals↗

Risk factors for rupture of abdominal aortic aneurysm based on three-dimensional study.

PURPOSE: Factors influencing the development or rupture of abdominal aortic aneurysms (AAAs) have not yet been confirmed. This study delineated the risk factors for rupture of AAAs as evaluated by means of a combination of three-dimensional (3D) reconstruction and clinical data analysis. METHODS: The study population comprised Japanese patients in whom an atherosclerotic AAA had been diagnosed between January 1980 and December 1997. We obtained 3D-based data by means of computer-aided 3D reconstruction from computed tomography studies of AAAs. The data included the tortuosity of the aneurysm, maximum transverse diameter, length of the aneurysm, aneurysmal volume, aneurysmal surface area, largest aneurysmal cross-sectional area, ratio of transverse aneurysmal diameter to the length of the aneurysm (T/L), and amount of mural thrombus. Clinical data were collected from patient files. All data were assessed by means of multivariate analysis for their predictive value for expansion or rupture of AAA. RESULTS: The most efficient predictor of annual expansion rate of maximum transverse diameter (EX-D) was a combination of largest aneurysmal cross-sectional area, tobacco use, and tortuosity. The most efficient predictor of annual expansion rate of aneurysmal volume (EX-V) was a combination of aneurysmal volume and blood urea nitrogen level. The most efficient predictors of aneurysmal rupture was a combination of EX-D, diastolic blood pressure, and T/L. CONCLUSION: Three-dimensional-based data on aneurysmal morphology, including T/L, largest aneurysmal crosssectional area, and aneurysmal volume, had strong predictive value for expansion and rupture of AAAs.

Aged↗

Short-term effect of beta-adrenoreceptor blocking agents on ocular blood flow.

PURPOSE: In this study the acute effect of the topically-delivered non-selective beta-blockers timolol and carteolol, and the selective beta-blocker betaxolol, were evaluated with respect to ocular blood flow, intraocular pressure (IOP) and vessel resistance in rabbits' eyes. METHODS: In a double masked randomized design, one eye of each subject (n = 9) received two drops of 0.5 % timolol or 2 % cartelol or 0.5 % betaxolol ophthalmic solution and a separate group of nine rabbits received two drops of placebo consisting of physiological saline in both eyes to serve as control. Using hydrogen clearance method, ciliary body blood flow (CiBF), choroidal blood flow (CBF), and retinal blood flow (RBF) were measured. IOP and systemic mean arterial pressure (MAP) of each subject were measured under same condition before and after the administration of respective drugs to calculate the ocular perfusion pressure (OPP) and vessel resistance. RESULTS: In timolol- and carteolol-treated eyes significant reduction was observed in IOP (p < 0.01), CiBF (p < 0.01), CBF (p < 0.01) and RBF (p < 0.01) compared to control eyes. However, in betaxolol-treated eyes a marginal reduction in IOP was observed accompanied by significant increase in CiBF (p < 0.01) and RBF (p < 0.05). The non-selective beta-blocker-treated eyes tended to have increased vessel resistance, whereas, selective beta-blocker-treated eyes tended to have decreased vessel resistance. CONCLUSIONS: Our current results comparing non-selective and selective beta-blockers suggest that the selective beta-blocker betaxolol may be more appropriate for maintenance of retinal blood flow in situations with low perfusion. Currently the mechanism for regulation of IOP is unclear; however, the findings from this study indicate that decreased CiBF may contribute to reduction in IOP.

Administration, Topical↗

Characteristics of health counselling in the workplace via e-mail.

This study was conducted to examine how health counselling via electronic mail (e-mail health counselling) was used in the workplace. The definition of health counselling employed in this study was 'any assistance to an individual seeking to solve any health problem'. A total of 2119 health counsellings conducted at a Japanese company's head office (700 employees) in 1997 and 1998 was used for the analysis, which compared four health counselling methods: e-mail, face-to-face, telephone and ordinary mail. This study distinguished four main characteristics of e-mail health counselling. First, the most and second most frequently used counselling methods were face-to-face and telephone counselling, at 70 and 15%, respectively, with e-mail health counselling ranked third at 13%. e-mail counselling was the second most frequently used method for employees in their 20s and 30s, while it ranked third among those over 40. Only 6% of employees in their 50s used e-mail counselling. Secondly, the proportion of mental health issues treated via e-mail counselling was significantly higher, at 26%, than for other counselling methods, which was at or below 10% for each of the other methods. Thirty-two per cent of all mental health counselling was conducted via e-mail. Thirdly, compared with face-to-face counselling, e-mail counselling dealt with more health issues related to primary prevention than with those related to secondary or tertiary prevention. Fourthly, compared with face-to-face counselling, e-mail counselling dealt more with health issues of third parties. These results suggest that e-mail health counselling may be useful in reaching people other than those targeted by the remaining counselling methods.

Adult↗

[The significance of extracurricular activities in the life of junior high school students].

In this study, the significance of extracurricular activities in the life of junior high school students were examined. Seventh and eighth graders participated in a two-stage questionnaire survey, administered in May and October. Based on developmental stage-environment fit theory (Eccles, Wigfield, & Schiefele, 1998), how well extracurricular activity settings fit needs of the students was analyzed. In support of the theory's hypothesis, results indicated that whether an extracurricular activity satisfied the student's developmental needs affected his/her sense of fulfillment and satisfaction in school life. In addition, the effect of seventh graders' commitment to extracurricular activities on their satisfaction of school life was stronger in October than in May. The findings suggested that for students who felt uneasy in class for whatever reasons, extracurricular activities provided an opportunity for relief.

Adolescent↗

[Future figures of specialties in the surgical field].

A quarter of century has passed since specialties and their governing boards were established in the surgical field. It is now time to reestablish more definitive and rational specialties as we begin the 21st century. The specialty of general surgery should be the first step and require general surgical training of four years or more. The subsequent specialties (subspecialties) would be gastroenterological surgery, cardiovascular surgery, respiratory organ surgery, and pediatric surgery. In addition, the numerous medical associations in Japan could be overseen by a newly created Japan Board of Medical Specialties (proposed name) to manage the various specialties.

Forecasting↗

[To err is human but error can be prevented].

It is believed that behind each reported medical error 29 unreported errors are hidden and in addition 300 irregularities are present. To prevent medical errors, one should learn from those latent errors to reorganize or correct systems and procedures. The Risk Management Committee is in charge of taking measures to prevent errors based on the analyzed data reported by risk managers and/or on incident/accident reports. The incident/accident reports should be made under a blame-free system and the concept should be thoroughly understood by all hospital staff. A lack of mutual communication, lack of a system to prevent medical errors, and lack of seriousness in everyday practice among physicians and nurses were found to be underlying causal factors in medical errors based on the lessons learned in our institution.

Humans↗

[Current status of adjuvant endocrine therapy for hormone responsive breast cancer].

Three important meetings on adjuvant hormone therapy for breast cancer were held recently: the 5th EBCTCG Meeting, NIH Consensus Meeting, 7th International Conference on Adjuvant Therapy of Primary Breast Cancer. The conclusions of these meetings are: 1. adjuvant hormone therapy should be indicated only for patients with estrogen/progesterone receptor positive cancer, 2. five years of tamoxifen is the standard care at present, 3. ovarian ablation by any means has been proved effective in premenopausal patients and LH-RH agonist should be given at least two years, and 4. aromatase inhibitors should not be used in clinical practice, because several prospective randomized trials are ongoing at present. The patients treated with LH-RH agonist combined with tamoxifen showed better relapse-free survival compared with LH-RH agonist alone in the INT-0101 trial. This was an important trial because combined hormone therapy had not been proven more effective than individual hormone therapy previously. Combined hormone therapy including LH-RH agonist may be considered in premenopausal patients. There is a growing consensus that chemotherapy is effective through the ovarian suppression. In this sense, hormonal therapy should be considered first for hormone responsive patients. On the contrary, standard chemotherapy has shifted from CMF combination to an anthracycline containing regimen. Chemoendocrine therapy may be considered in high risk patients.

Antineoplastic Agents, Hormonal↗

Financial assistance in promoting occupational health services for small-scale enterprises in Japan.

In spite of the diversified views on the governmental financial assistance in promoting occupational health services (OHS) for small-scale enterprises (SSE), the issue has not been much studied. Considering the large differences between countries in the degree of governmental financial assistance, the international comparative research will provide insight into its advantages and disadvantages. In order to conduct such comparative research, the status of each country must first be clarified. This informative piece of study aims at stimulating researchers in other countries to share their experiences and facilitate future comparative studies. This study was conducted to clarify the financial assistance of the Japanese government for SSE. Published reports on financial assistance for SSE were collected and used for the study. The Ministry of Labor initiated the policy of subsidizing OHS for SSE in the early 1960s. Activities to be subsidized through four routes included primary and secondary prevention of occupational injuries and diseases. The amount of subsidy was limited from one-third to two-thirds of costs. There was a fourteen-fold increase in the amount of subsidies for SSE from US$ 7 million in 1986 to US$ 98 million in 1998. The long history of financial assistance for SSE and the increasing amount of subsidies suggest that the Ministry of Labor recognizes the importance of financial assistance in promoting OHS in small scale enterprises.

Financial Support↗

Clustered cancer cells show a distinct adhesion behavior from single cell form under physiological shear conditions.

It remains a question whether hematogeneous metastasis arises from a single cancer cell attached to the local endothelium or from a cluster of cancer cells trapped in the vascular bed in the target organ. Adhesive interaction of the single cell form and the clustered form of cancer cells was examined under flow conditions, using two subclones of mouse colon adenocarcinoma Colon 26. A subclone NL17, but not NL14, formed many clusters composed of tumor cells and platelets just after the addition of platelet rich plasma (PRP). Under the shear of 1.0 dyn/cm3, the clustered form of NL17 tethered on laminin or mouse endothelial cell line in hepatic sinusoids (HSE) more frequently than the single cell form of NL17 and NL14. However, all of the clusters showed only transient attachment and never underwent stable arrest on coated laminin, while the single cell form of NL14 and NL17 underwent immediate arrest under shear conditions. On HSE stimulated with TNF-alpha, a small number of NL17 clusters made stable adhesion, although all the clusters detached if the shear stress was increased above 4.0 dyn/cm2. In contrast, the single form of arrested NL17 as well as NL14 remained adherent even at shear of 8.0 dyn/cm2. Compared with single cell, binding of cancer cell clusters to laminin and HSE showed lower resistance to shear stress, although they had adhesive interactions more frequently in flow condition. Since NL17 cells form significantly more metastases by intravenous injection in vivo, our data suggest that "stable adhesion" observed in our flow assay system is not always a prerequisite for clustered cancer cells to develop into metastatic lesions.

Adenocarcinoma↗