Biomedical subjects

N Tsukamoto

Publications and source records attributed to N Tsukamoto.

At least 73 records · Page 4Linked to original sources

PubMed1995

Development of a personal computer's viewing station for the IS&C magneto-optical disk.

We developed a display station for the medical images stored in the IS&C (Image Save and Carry) magneto-optical disk. This station consisted of the personal computer and the magneto-optical disk drive. The performance of this system was evaluated and was compared with the Unix workstations. We found that the personal computer system had an adequate ability to display medical images. It provided, moreover, for portability and practical use of medical information.

Data Display↗

PubMed1994

[Parallel processing of dose calculation for external photon beam therapy].

We implemented external photon beam dose calculation programs into a parallel processor system consisting of Transputers, 32-bit processors especially suitable for multi-processor configuration. Two network conformations, binary-tree and pipeline, were evaluated for rectangular and irregular field dose calculation algorithms. Although computation speed increased in proportion to the number of CPU, substantial overhead caused by inter-processor communication occurred when a smaller computation load was delivered to each processor. On the other hand, for irregular field calculation, which requires more computation capability for each calculation point, the communication overhead was still less even when more than 50 processors were involved. Real-time responses could be expected for more complex algorithms by increasing the number of processors.

Mathematical Computing↗

PubMed1994

The promotion of invasion through the basement membrane of cervical carcinoma cells by fibronectin as a chemoattractant.

An in vitro migration and invasion assay was used as the model system to study the effect of 3T3 fibroblast conditioned medium (FCM) and purified human fibronectin on the invasion of cervical carcinoma cells. The 3T3 FCM significantly enhanced both the migration and the invasion of a cervical carcinoma cell line, HeLa. This enhancement of migration and invasion was inhibited by anti-fibronectin antibody. Purified fibronectin alone enhanced the invasion in a dose-dependent manner for all cervical carcinoma cell lines, HeLa, CAC-1 and TMCC. The pretreatment of cells with cell binding aminosequences, GRGDSP and/or YIGSR blocked the enhancement of cell invasion. The implication of these findings for the invasion of cervical carcinoma is discussed.

3T3 Cells↗

PubMed1994

Detection of human papillomavirus types 16 and 18 in primary and in metastatic lesions of cervical carcinomas.

Human papillomavirus (HPV) types 16 and 18 are most prevalent in cervical carcinomas and are also present in metastatic sites. Thirty-six patients with lymph node metastases were examined for the possible presence of HPV 16 and 18 DNA sequences in the primary tumors as well as in metastatic lymph nodes. Polymerase chain reaction (PCR) analysis revealed the presence of the genome of HPV type 16 (HPV 16) in 17 tumors (47%) and that of HPV type 18 (HPV 18) in 2 tumors (6%), while 17 tumors (47%) were negative for both types. Of the 17 HPV 16-positive patients, 15 metastatic lymph nodes were also positive and 2 were negative. In 2 patients positive for HPV 18, the metastatic sites were negative. All the 17 patients negative for HPV in the primary tumors were also negative for HPV 16 and HPV 18 in the metastatic lymph nodes. These data confirmed the positive correlation of HPV DNA status between primary and metastatic tumors. However, the discrepancy in 11% of cases was attributed to presence of heterogeneous clones in the primary tumor.

Adult↗

PubMed1994

Adenoma malignum of the uterine cervix detected by imaging methods in a patient with Peutz-Jeghers syndrome.

Adenoma malignum of the uterine cervix in a 25-year-old Japanese woman with Peutz-Jeghers syndrome (PJS) is described. A cervical multicystic mass was detected by CT scan, sonography, and MR imaging. These imaging findings strongly suggested the presence of adenoma malignum in spite of normal Pap smear, colposcopy, and cervical biopsy reports. Radical hysterectomy, bilateral salpingo-oophorectomy, pelvic lymphadenectomy, and para-aortic lymph node biopsy were performed after confirmation of adenoma malignum by conization. Both ovaries showed multicentric sex cord tumor with annular tubules. She is alive and well with no evidence of disease 23 months after surgery. Imaging methods including sonography, CT scan, and MR imaging may be useful aids in detecting the presence of adenoma malignum, especially in patients with PJS.

Adenoma↗

PubMed1994

Clonality in chronic myeloproliferative disorders defined by X-chromosome linked probes: demonstration of heterogeneity in lineage involvement.

The restriction fragment length polymorphisms (RFLP) of the X-chromosome phosphoglycerate kinase (PGK) and hypoxanthine phosphoribosyltransferase (HPRT) genes were used to study the clonal basis of the chronic myeloproliferative disorders (CMPD). Analyses were performed on granulocyte and T-lymphocyte fractions obtained from 24 females; 13 had essential thrombocythaemia (ET), eight polycythaemia vera (PV) and three myelofibrosis with myeloid metaplasia (MMM). All 24 of these patients had monoclonal patterns of X-inactivation in the granulocyte fraction. For the T-lymphocyte fraction, non-clonal patterns of X-inactivation were observed in 8/13 patients with ET, 7/8 with PV and 1/3 with MMM, while the remaining eight subjects were found to have monoclonal patterns of X-inactivation. Our findings suggest that the majority of the CMPD in these patients originated from a relatively committed progenitor cell without the capacity to differentiate into T cells, and convincingly demonstrated heterogeneity of lineage involvement.

Adult↗

PubMed1994

[Clinical significance of positive blood cultures in the Nagasaki Rosai Hospital during the past 6 years].

In this clinical study we tried to find out the clinical significance of positive blood cultures between Jan. 1984 and Dec. 1989 in the Nagasaki Rosai Hospital. In this period the association between the isolated bacteria from blood cultures (398 specimens: 17.9%) and clinical background were evaluated. Each year the positive cultures were seen in about 18-20%. The distribution of bacteria showed increase percentage of the gram-positive organisms such as coagulase-negative Staphylococcus. Gram-negative organisms in included P. aeruginosa, A. calcoaceticus and E. coli. A. calcoaceticus was frequently found from the dept. of neurosurgery. Fungus, mostly Candida, was isolated in about 10-20%. The specimens were provided from department of internal medicine (62.9%) and neurosurgery (22.8%). An analysis of 213 episodes of 188 bacteremic cases was made. The onset of bacteremia had two peaks, 24 h or 1 month, after admission. The primary infected sites were the urinary tract (26.7%), respiratory system (14.5%) and central nervous system (6.1%). The central venous catheter was an important infected site. The major underlying diseases included acute cerebrovascular diseases, cardiac failure due to valvular heart diseases or acute myocardial infarction and/or iatrogenic immunocompromised state. The major complications were disseminated intravascular coagulation (DIC) (24.4%) and multiple organ failure (MOF) (8.9%). Half of the DIC episodes was caused by gram-positive cocci such as CNS, E. faecalis and MRSA. 68.4% of MOF episodes was associated with gram-negative bacteria. While the remainder was caused by gram-positive cocci including CNS and MRSA.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1994

Nucleotide sequence of the aknA region of the aklavinone biosynthetic gene cluster of Streptomyces galilaeus.

A 3.4-kb BamHI fragment that is assumed to be a part of the aklavinone biosynthetic gene cluster of Streptomyces galilaeus 3AR-33 and contains the genes required for the early stage of polyketide biosynthesis was sequenced. The nucleotide sequence of the region that hybridizes to the actIII probe reveals the presence of a gene, aknA, whose deduced protein product is very similar to the ActIII protein and other known oxidoreductases. The predicted AknA protein is believed to be responsible for catalyzing the reduction of the keto group at the ninth carbon from the carboxyl terminus of the assembled polyketide to the corresponding secondary alcohol. The predicted AknA protein has a calculated molecular mass of 27,197 Da (261 amino acids) and the highly conserved sequence Gly-Xaa-Gly-Xaa-Xaa-Ala commonly seen in oxidoreductases. Cloning and sequence analysis of the aknA region of the 2-hydroxyaklavinone-producing strain S. galilaeus ANR-58 identified an alteration in the gene, confirming that the aknA gene is essential for aklavinone biosynthesis.

Amino Acid Sequence↗

PubMed1994

Octreotide treatment results in the inhibition of GH gene expression in the adenoma of the patients with acromegaly.

Seven patients with growth hormone (GH)-secreting pituitary adenoma were treated preoperatively with octreotide (Sandostatin or SMS 201-995; a somatostatin analogue), and were compared with 18 non-treated patients in their clinical courses and adenoma analyses. Octreotide treatment improved the endocrinological data in all 7 cases. The octreotide-treated adenomas were soft and easily removed by suction and curettage. The postoperative normalization of endocrinological data was encountered more often in the octreotide-treated cases than in the non-treated, although the statistical significance was not observed by the limited number of cases. The adenoma tissues were examined with conventional histology and immunohistochemistry, and the amount of GH messenger ribonucleic acid (mRNA) was quantitatively assessed. The studies demonstrated: 1) No fibrosis nor necrosis was observed in the adenomas from the octreotide-treated patients. 2) Immunohistochemistry for human GH revealed no remarkable differences between the octreotide-treated and the non-treated adenomas. 3) The amounts of GH mRNA in the adenoma from the octreotide-treated patients were 4.2 +/- 1.8 (mean +/- SEM; expressed in an arbitrary unit) and were significantly less than those from the non-treated (33.6 +/- 9.1). These data suggest that octreotide inhibits not only GH release from the adenoma but also its biosynthesis.

Acromegaly↗

PubMed1994

Reassessment of myometrial invasion in endometrial carcinoma.

OBJECTIVE: To assess different methods of measuring the depth of myometrial invasion in endometrial carcinoma as a prognostic factor. METHODS: Eighty-eight cases of stage I or II endometrial carcinoma treated initially by hysterectomy between 1979-1989 were reviewed histologically. Three methods of measuring myometrial invasion were evaluated: 1) percentage of invaded tumor thickness to whole thickness of myometrium, 2) percentage of whole tumor thickness to total thickness of tumor and myometrium, and 3) distance from the tumor-myometrial junction to the uterine serosa. We evaluated the effect of several factors on prognosis by multivariate analysis using Cox regression models. RESULTS: Myometrial invasion determined by these three measurement methods was associated significantly with survival in a univariate analysis. When myometrial invasion assessed by each method and other prognostic factors were entered into a multivariate model, the distance from the tumor-myometrial junction to the uterine serosa, lymph-vascular space invasion, and cervical stromal involvement were identified as independently significant prognostic factors. CONCLUSION: This method of evaluating myometrial invasion by measuring the distance from the tumor-myometrial junction to the uterine serosa was most useful as a correlate with survival.

Carcinoma↗

PubMed1994

[A multicenter cooperative study on supplementary chemotherapy of uterocervical cancer. The Kyushu UFT Study Group of Uterocervical Cancer].

A randomized study was carried out by means of multicentered cooperation in respect to 5-FU and UFT administration, which was used as the supplementary chemotherapy after treatment of uterocervical cancer. Five years later, the improvement in prognosis was examined. Out of all the cases with radical operation + supplementary chemotherapy as well as with radical operation + postoperative radiotherapy + supplementary chemotherapy, 98 cases were ratable. The analysis of 98 cases led to no significant difference in the survival rate between the 5-FU administration group and the UFT administration group. As to the cases with supplementary chemotherapy + postoperative radiotherapy only, the survival rate was significantly higher in the UFT administration group than in the 5-FU administration group. During the administration, severe adverse side effects developed neither in the 5-FU administration group nor in the UFT administration group. These results suggest that UFT may be useful as a factor in supplementary chemotherapy of uterocervical cancer in combination with radiotherapy.

Administration, Oral↗

PubMed1993

[Supporting system for CT diagnosis referring to previous cases].

Since radiologists make diagnoses by prior experience, images from previous studies are helpful in making diagnoses. We have developed an assisting system for CT image interpretation. The Case-Based Reasoning (CBR) method was implemented in order to search reports and images of past cases. This system translates the text of findings written in Japanese into descriptive units, and evaluates similarities between the current case and all stored cases (case base). The CT images of the similar cases can be retrieved for reference images, as well as reports which show examples of interpretation. Since this system employs a key word extracting method, translation and comparison can be performed within a second. In order to evaluate the validity of the similarity metrics, the correspondence between CT diagnoses by radiologists and those of the best matched cases by this system was examined. Forty-eight test cases were obtained from the reports of three radiologists. The case base was consisted of 1,060 cases written by other four radiologists of other hospitals. The matching ratio between diagnoses of test cases and most similar cases was 68.1%. The ratio became higher with the increasing number of stored cases. In clinical study of other 45 test cases, the best matched three diagnoses of 43 cases (95.6%) contained the established diagnoses. In 44 cases (97.8%), radiologists could make correct diagnoses by using this system. This system is useful to prevent misdiagnoses due to preconceptions and/or lack of knowledge. The diagnostic accuracy was expected to improve by using this system.

Diagnosis, Computer-Assisted↗

PubMed1993

Metastatic adenocarcinoma to the uterine cervix from gastric cancer. A clinicopathologic analysis of 16 cases.

BACKGROUND: Metastatic adenocarcinoma to the uterine cervix from gastric cancer is rare, and the clinicopathologic features of this metastasis are unclear. METHODS: A clinicopathologic review of 16 patients with metastatic adenocarcinoma to the uterine cervix from gastric cancer was performed. RESULTS: The ages of the patients ranged from 29 to 57 years, and 81.3% of the patients were premenopausal. Nine of the patients had undergone gastrectomy previously. In 11 patients the histologic type of the gastric cancer was poorly differentiated adenocarcinoma and, in 5 patients, signet ring cell carcinoma. The cervical metastasis was diagnosed 11-121 months (mean, 57.5 months) after the diagnosis of the gastric cancer in 10 of the patients. In six patients, the cervical metastasis was discovered synchronously or before the diagnosis of the gastric cancer. The colposcopic findings were normal in 57.1%, but 56.3% had abnormal cervical smears. In all patients, tumor cells were present in the dilated lymphatics of the cervix. Metastases to the uterine body and bilateral ovaries were common, and half of the patients had metastases to the paraaortic lymph nodes. Extirpation of the cervix was performed in six patients. The prognosis was poor, regardless of the treatment method. CONCLUSIONS: The route of metastasis to the cervix is surmised to be retrograde lymphatic, and this extension is often slow. Periodic gynecologic examinations should be performed indefinitely for premenopausal female patients with advanced gastric cancer.

Adenocarcinoma↗

PubMed1993

Expression of alpha-smooth muscle actin in benign or malignant ovarian tumors.

We compared the expression of alpha-smooth muscle actin (alpha-SMA) between benign and malignant human ovarian tissues by immunohistochemical staining and Western blot analysis using the monoclonal antibody specific to alpha-SMA. In normal human ovaries, alpha-SMA was found in the blood vessel walls, muscle fibers, and stromal cells surrounding the follicles. The main source of alpha-SMA in the benign ovarian tumors was the blood vessel walls which highly expressed the alpha-SMA throughout the tumor. In malignant tumor tissues, however, the vessels located in or close to the cluster of cancer cells did not express alpha-SMA. It corresponded to the results of the Western blot analysis, showing that the amount of alpha-SMA in malignant ovarian tumor tissues was much smaller than that in benign tumor tissues. Thus, the alteration in alpha-SMA expression seems to reflect the qualitative difference in vessels between benign and malignant ovarian tissues, and therefore alpha-SMA is considered to potentially be a histopathologically useful marker for indicating the malignant potential of ovarian tumors.

Actins↗

PubMed1993

Skin metastasis from carcinoma of the uterine cervix.

Of 1190 patients with carcinoma of the uterine cervix, 15 (1.3%) developed skin metastases. The incidence of skin metastasis was 0.8% in stage I, 1.2% in stage II, 1.2% in stage III, and 4.8% in stage IV. The incidence of skin metastasis seemed to be higher in patients with adenocarcinoma and undifferentiated carcinoma than in patients with squamous cell carcinoma. The interval between the diagnoses of cervical cancer and skin metastasis ranged from 0 to 69 months, with a mean of 16.9 months. The most common sites of skin lesions were the abdominal wall and vulva, followed by the anterior chest wall. Skin lesions presented as nodules in 86.7% (13/15), and 66.7% of the patients had multiple lesions. Skin metastasis was detected as the initial metastatic lesion in 9 patients. However, only 4 patients had neither local recurrence nor other distant metastasis at the time of diagnosis of skin metastasis. The prognosis was grave, but 3 patients survived more than 12 months after the diagnosis of skin metastasis. The main treatment for these patients was extirpation of the skin lesion followed by radiotherapy.

Abdominal Muscles↗

PubMed1993

Relationship between paraaortic lymph node involvement and intraperitoneal spread in patients with ovarian cancer--a multivariate analysis.

In 125 patients with epithelial ovarian cancer (FIGO stages I-IV), 32 (26%) had paraaortic lymph node (PAN) metastases. The estimated 5-year survival rate of PAN-negative patients was 71%, while that of PAN-positive patients was 17% (P < 0.0001). Positive rates of PAN metastasis at each stage level, based only on intraperitoneal spread of the disease, were 2% for stage I, 9% for stage II, 43% for stage III, and 87% for stage IV. According to univariate analysis, histological grade, and all disease site parameters examined, such as subdiaphragmatic surface, liver and spleen capsule, intestines and mesentery, omentum, pelvic peritoneum, sigmoid colon and rectum, uterus and tubes, and peritoneal cytology, showed a statistically significant correlation to the presence of PAN metastasis. Multivariate analysis using the logistic regression model revealed that the omental involvement, uterine and tubal involvement, and histological grade were independently correlated with PAN metastasis. The relative risk of PAN metastasis in the patients with these three factors is 18.5 times higher than that in patients without these factors. The present data suggested that, for the disease with omental and/or uterine and tubal involvement, surgical evaluation of PAN is mandatory in order to perform correct FIGO staging.

Abdominal Neoplasms↗

PubMed1993

Ovarian mucinous cystadenocarcinoma with sarcoma-appearing mural nodule of anaplastic carcinoma.

An ovarian mucinous cystadenocarcinoma with sarcoma-appearing solid mural nodules in an 18-year-old Japanese woman is reported. Right ovarian cyst had two poorly circumscribed, solid nodules and several tiny studs. Microscopically, the epithelial elements consisted of benign, low malignant potential and malignant mucinous tumors. The mural nodules were made up of highly malignant anaplastic cells simulating sarcoma. In one of the mural nodules, continuity between the malignant mucinous cells and sarcoma-appearing cells was identified. Immunohistochemically, the sarcoma-appearing nodule was uniformly positive for vimentin and focally positive for epithelial markers such as EMA, CAM5.2, and AE1/AE3. This case demonstrated an orderly transformation and dedifferentiation of epithelial cells to undifferentiated mesenchymal cells. Although she had stage IIb disease, she lived disease free for 3 years and 5 months after surgery followed by 10 courses of chemotherapy containing cisplatin and Adriamycin.

Adolescent↗

PubMed1993

Fatal outcome of a patient with severe aplastic anemia after treatment with metenolone acetate.

A 75-year-old man suffering from severe aplastic anemia was treated first with cyclosporin A, then with steroid pulse therapy, and subsequently with metenolone acetate. Marked elevation of transaminases was detected following initiation of treatment with metenolone acetate. This was followed by hepatic failure and death. Histopathological findings in autopsy specimens were compatible with the diagnosis of drug-induced liver impairment, for which metenolone acetate was considered the most likely causative agent. Liver impairment as a side effect of the use of this drug has been thought to be mild, reversible and rather infrequent. However, as demonstrated in the case described here, it is apparent that extreme caution should be exercised when using this drug in debilitated patients.

Aged↗