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Biomedical subjects

S Tamura

Publications and source records attributed to S Tamura.

At least 451 records · Page 25Linked to original sources
PubMed1992

Impaired long-term T cell immunity to Epstein-Barr virus in patients with nasopharyngeal carcinoma.

The long-term T cell immunity to Epstein-Barr virus (EBV) is considered to play an important role in suppressing proliferation of EBV-infected B cells and outgrowth of EBV-associated tumors. It can be manifested and quantified by the EBV-induced focus regression assay. In the present study, we examined the strength of T cell immunity to EBV in patients with nasopharyngeal carcinoma (NPC) and other cancers originating from the head and neck region. In contrast to patients with other types of cancers, including EBV-negative NPC, patients with EBV-positive NPC were found to have a profound impairment in the long-term T cell immunity to EBV.

Adolescent↗
PubMed1992

Elevated levels of plasma transforming growth factor-beta in patients with hepatocellular carcinoma.

We measured the plasma transforming growth factor-beta (TGF-beta) concentration in 14 patients with human hepatocellular carcinoma (HCC) and 9 age-matched normal subjects using growth inhibition assay of mink lung epithelial cells. The calculated plasma TGF-beta concentration in the patients with HCC was 28.6 +/- 27.9 ng/ml (mean +/- SE), showing significant elevation compared with that in 9 normal subjects (5.3 +/- 3.3 ng/ml, P less than 0.01). In three cases, we could measure plasma TGF-beta levels before and after their treatment for HCC. The plasma TGF-beta levels decreased from 59.0 to 18.2 ng/ml after hepatic resection in one case, and from 24.0 to 10.7 ng/ml and from 12.4 to 3.4 ng/ml after transhepatic arterial embolization in the other two cases. These data indicate that plasma TGF-beta level is elevated in patients with HCC, probably due to release from HCC tissues.

Animals↗
PubMed1992

mRNA levels of catalytic subunits of protein phosphatases 1, 2A, and 2C in hepatocarcinogenesis.

The mRNA levels of three phosphoseryl/phosphothreonyl protein phosphatases, PP1, PP2A and PP2C, in rat liver have been determined by Northern blot analysis in various stages of rat chemical hepatocarcinogenesis using a Solt-Farber model. Five weeks after administration of diethylnitrosamine, the mRNA levels of PP1 alpha, PP2A and PP2C were elevated 8, 29 and 11 times, respectively, as compared to those of the control livers. However, in primary hepatoma induced according to the Solt-Farber model, the mRNA levels of all three protein phosphatases were dramatically decreased to normal levels or even to much lower levels, whereas the mRNA level of glutathione S-transferase placental form, a tumor marker protein, was greatly elevated as compared with that of the control livers. In a poorly differentiated hepatoma AH13, a line of rat ascites hepatoma, the mRNA level of PP1 alpha was 5.6 times higher than that of the control livers, whereas the mRNA lever of PP2C was almost the same as that of the control livers and the level of PP2A mRNA was distinctly lower than that of the control livers. These data appear to suggest some involvement of protein phosphatases in hepatocarcinogenesis.

Animals↗
PubMed1992

Detection of latent subclones with abnormal karyotypes by long-term bone marrow cultures in cases of myelodysplastic syndrome.

Cytogenetic studies on non-adherent cells from long-term bone marrow cultures (LTBMC) were done for 23 patients with myelodysplastic syndrome (MDS) and compared with the karyotypes detected during their clinical courses. Of 14 cases with normal karyotype before culture, abnormal karyotypes were detected first in LTBMC from seven. Novel abnormal karyotypes were observed after LTBMC in two of four cases which had had both normal and abnormal karyotypes before culture. Abnormal karyotypes were also newly detected in four of five cases with only abnormal karyotypes before culture. Among 13 cases in which abnormal karyotypes were observed during the cultures, three patients showed the same karyotypes 1-11 months later in their clinical courses. These findings suggest that our LTBMC might be useful for evaluating the prognosis and choice of treatment for MDS patients.

Adult↗
PubMed1992

Sensitization against pancreatic antigen in Sjögren's syndrome and chronic pancreatitis. Preliminary communication.

A fractionated pancreatic antigen was prepared using a monoclonal antibody, SP3-1, which reacts with the duct cells of various exocrine organs. The cell-mediated immune response to this antigen was studied by the leukocyte migration inhibition test (LMT) in patients with chronic pancreatitis (CP), Sjögren's syndrome (SjS), and chronic sialoadenitis (CSA). The migration index (MI) for the LMT was 0.97 +/- 0.07 in normal controls (mean +/- SD, n = 11, range: 0.88-1.08). A positive LMT result (MI less than 0.82 = mean -2 SD in controls) was obtained in 7/8 (88%) SjS patients, 4/22 (18%) CP patients, 2/3 CP patients with SjS, and 0/3 CSA patients. These results indicated sensitization against the pancreatic antigen in most SjS patients and some CP patients, and may suggest that an immune response to a common antigenic determinant of the duct cells of exocrine glands plays a role in the pathophysiology of both diseases.

Antibodies, Monoclonal↗
PubMed1992

Transthyretin (prealbumin) in the pancreas and sera of newly diagnosed type I (insulin-dependent) diabetic patients.

We investigated transthyretin (TTR) in the pancreases and sera of 10 newly diagnosed type I diabetic patients by immunohistochemistry and nephelometry. In the type I diabetic pancreases, glucagon-positive A-cells showed strong immunoreactivity for TTR, the intensity and distribution pattern of which corresponded to those in normal subjects. Morphometric analysis revealed that the amount of strongly TTR-positive A-cells was not significantly different from that in normal subjects. On the contrary, insulin-positive B-cells, which normally show uneven and weak TTR immunoreactivity, decreased in number, and only a few residual B-cells showed faint immunoreactivity. Neither somatostatin cells nor pancreatic polypeptide cells were positive for TTR. The serum TTR concentration showed a significant decrease in type I diabetic patients compared with that in normal subjects (P less than 0.005). These data suggest that the synthesis or storage of TTR in A-cells is not affected, but that in B-cells is impaired in type I diabetes. The decrease in serum TTR might be one of the features of metabolic disorders in type I diabetes.

Adult↗
PubMed1992

Alteration of the level of protein phosphatase 2C (IA) mRNA during the course of differentiation of skeletal muscle cells.

On Northern hybridization using the cDNA of type 2C protein phosphatase as a probe, substantial amount of the mRNA of type 2C protein phosphatase was detected in various organs of rats, suggesting that the type 2C protein phosphatase gene is a housekeeping gene. A relatively high level of the mRNA, however, was found in skeletal muscle compared with other organs. Similar results were obtained with the organs of mice. In addition, the mRNA level in C3H10T1/2 cells (embryonal mesenchymal cells of mice) was much lower than in mature skeletal muscle of mice. The mRNA level of type 2C protein phosphatase was enhanced in accordance with the differentiation of the C3H10T1/2 cells into myoblasts induced by the transfection of MyoD cDNA. These results suggest that type 2C protein phosphatase is related to the mechanism of differentiation of skeletal muscle cells.

Animals↗
PubMed1992

Small cell lung cancer with extensive cutaneous and gastric metastases.

A case of a 60-year-old Japanese woman with small cell lung cancer involving skin and stomach is reported. She was diagnosed as primary small cell lung cancer accompanied by extensive cutaneous metastases. Three months after the last chemotherapy, she complained of nausea and vomiting. Brain CT scan showed no evidence of central nervous system involvement. Upper gastrointestinal study and upper gastrointestinal fiberscopy revealed multiple metastatic gastric tumors. Skin and stomach are uncommon metastatic sites for any malignancy. Furthermore, only a few cases with gastric metastasis could be diagnosed during their lifetime.

Carcinoma, Small Cell↗
PubMed1992

A case of adenoid cystic carcinoma of the bronchus producing cancer-associated antigen, CA19-9.

A 73-year-old male was admitted to Hyogo College of Medicine Hospital for further evaluation of chest x-ray abnormalities. Chest roentgenogram taken at admission showed right lower lobe atelectasis and bronchoscopic examination revealed an endobronchial tumor obstructing the left lower lobe bronchus. The biopsy specimen showed cribriform adenoid cystic carcinoma. The serum CA19-9 level was markedly elevated at admission, leading to immunohistochemical analysis of the biopsy specimen. As a result, in the tumor, CA19-9 was positively stained. This is probably the first reported case of adenoid cystic carcinoma of the bronchus which produces CA19-9.

Aged↗
PubMed1992

Comparison of the survivals between bone marrow transplantation and chemotherapy for acute leukemia in first remission--a Japanese single institution study.

The outcome of sixty-four patients with acute leukemia in first remission who had been treated with either bone marrow transplantation (BMT) or conventional chemotherapy was retrospectively evaluated (a median follow-up of 37 months). Among them, 26 patients (age range; 14-42 years) received allogeneic BMT from HLA-identical siblings and 38 patients (age range; 13-43 years) who had no HLA-identical donors undertook the continued combination chemotherapy. Kaplan-Meier product-limit estimate of actuarial survival of acute myelogenous leukemia (AML) patients was 48.9% for the BMT group and 15.7% for the chemotherapy group (p = not significant, NS). For acute lymphoblastic leukemia (ALL) patients, the survival following BMT was 80.2% and was significantly higher than that of the chemotherapy group of 33.3% (p < 0.05). The disease-free survival of AML and ALL for the BMT group was 34.3% and 36.5%, respectively, which was higher than that of the chemotherapy group (16.7% and 23.4%, respectively (p = NS)). These findings in our Japanese single institution study suggested that BMT may be the treatment of choice for adult patients with acute leukemia in first remission if they had suitable donors and that more effective therapeutic regimens were necessary for patients without compatible donors in order to obtain the longer remission duration.

Acute Disease↗
PubMed1992

[A basic study on the association of Epstein-Barr virus with nasopharyngeal carcinoma--detection and genotypic analysis of Epstein-Barr virus associated with nasopharyngeal carcinoma in Japanese patients].

Epstein-Barr virus (EBV) is known to be associated with two human malignant diseases, nasopharyngeal carcinoma (NPC) and endemic Burkitt's lymphoma. In this study, the genotypes of EBV in tissues from 13 NPC patients in Japan were analyzed by Southern blot hybridization using EBV genome fragment probes. Ten of the cases contained reiterated sequences (EBV BamHI-H, -B1*, -K fragments), showing that only one genotype was detected in each specimen. One of these had a BamHI fragment containing a fused sequence of BamHI-Y and -H. In all except one case, a single-sized EBV-joined terminus was observed in each NPC specimen, implying evolution of the carcinoma from a single EBV-infected cell. One metastatic lymph node (which was not a primary epipharyngeal tumor) contained EBV with heterogeneous termini suggesting production of linear virion DNA. The type C variant resulting from loss of a BamHI site between the BamHI-W1* and -I1* regions was observed in 7 of the 10 cases, and the other 3 cases had a separated BamHI-I1* fragment. As reported by Lung et al. (Virology, 177: 44-53, 1990), the type C variant appears to be dominant among Japanese strains, as it is in Southern China. In contrast to their findings, however, the "f" variant with an extra BamHI site in the BamHI-F region which they found to be strongly associated with NPC specimens from Southern China, was detected in only one case. The present study, therefore, did not support the specific association of the "f" variant with NPC in Japanese patients. We conclude that the EBV in NPC tissues exists in variants. Further studies along these lines, could help to explain the epidemiology of EBV.

Adult↗
PubMed1992

Synthesis and antifungal activities of pradimicin derivatives, modification at C4'-position.

The 4'-N-alkyl(1 approximately 10) and 4'-N-acyl derivatives (11 approximately 21) of pradimicins (PRMs) were synthesized by trimethylsilylation of PRMs A, C and FA-1 followed by condensation with appropriate alkylating and acylating agents. The 4'-hydroxy derivatives (23 and 24) were synthesized from PRM FA-2 in a 3-step sequence. Among these compounds, the 4'-N-carboxyl substituted alkyl (1, 5, 8 and 10), 4'-N-formyl (11) and 4'-axial-hydroxy (23) derivatives retained the antifungal activity of the parent compounds and showed great improvement in water solubility.

Anthracyclines↗
PubMed1992

Enhanced expression of type 2C protein phosphatase gene during myogenic differentiation of C3H10T1/2 cells.

Type 2C phosphatase is one of the four major protein serine.threonine phosphatases (types 1, 2A, 2B and 2C). The mRNA level of the enzyme protein was 11.5 times higher in mouse skeletal muscle than in undifferentiated mesenchymal cells (C3H10T1/2). The mRNA level was enhanced 4.2-fold in accordance with the differentiation of C3H10T1/2 cells into myoblasts induced by transfection with a MyoD1 expression vector, and this high level was maintained in terminally differentiated myotubes. Furthermore, type 2C phosphatase activity in both myoblast and myotube fractions was slightly higher than in control C3H10T1/2 cells. These results indicate that the expression of type 2C phosphatase gene is enhanced during the course of myogenic differentiation.

Animals↗
PubMed1992

[Immunohistochemical analysis of CA19-9, SLX, and CA125 in adenoid cystic carcinoma of trachea and bronchus].

We examined the usefulness of 3 carbohydrate antigens, CA19-9, CA125, and SLX, as tumor markers in adenoid cystic carcinoma of the trachea and bronchus, immunohistochemically and clinically. CA19-9 and SLX were detected immunohistochemically in normal tracheal and bronchial glands, but CA125 was not detected. Bronchial secretions obtained from 7 patients without cancer contained high levels of these 3 carbohydrate antigens. There was positive immunohistochemical staining for CA19-9, CA125, and SLX in 5 of 9, 1 of 9, and 3 of 8 patients with tracheal or bronchial adenoid cystic carcinoma, respectively. In a case of bronchial adenoid cystic carcinoma in whom pretreatment serum CA19-9 showed a very high level, this marker changed in parallel with the clinical course. These results suggest the possibility that CA19-9 and SLX could be used as useful markers in patients with tracheal and bronchial adenoid cystic carcinoma.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1992

[Motility and mucosal hemodynamics of the lower esophagus after transabdominal esophageal transection for esophageal varices].

Lower esophageal motility and mucosal hemodynamics were investigated in 20 patients who underwent transabdominal esophageal transection for esophageal varices (ET), to evaluate their association with reflux esophagitis and variceal recurrence. In the manometric study with microtransducer catheter, maximum swallowing pressure in the lower esophagus of the patients was significantly lower than that of the healthy controls (20 cases) (26.1 +/- 20.5mmHg vs. 80.0 +/- 10.0mmHg: p < 0.01), while high pressure zone pressure did not differ between the two groups. In comparison between patients with and without esophagitis (E(+) and E(-)), maximum swallowing pressure of E(+) was statistically lower than that of E(-) (12.4 +/- 18.7mmHg vs. 31.0 +/- 19.1mmHg: p < 0.05). In the hemodynamic study by reflectance spectrophotometry, the index of esophageal mucosal blood volume (IHb) and the index of oxygen saturation of hemoglobin (ISo2) of E(+) and E(-) were no different from those in the patients with non-operated esophageal varices (10 cases). Although there was no correlation between the recurrence of RC-sign and mucosal microcirculation, the patients with larger varices tended to have a higher IHb and a patients with F1-varices had significantly lower ISo2 than the patients without varices. This study indicated that the poor clearance ability after ET may lead to reflux esophagitis and the patients with variceal recurrence had the congested mucosal microcirculation, compared to those without variceal recurrence.

Adult↗
PubMed1992

[A case of central nervous system sarcoidosis, presenting with psychomotor seizure].

A rare case of neurosarcoidosis presenting with psychomotor seizure is reported. A 35-year-old woman was admitted to our ward for further evaluation of syncopal attacks and suspected sarcoidosis. The patient had a history of syncopal attacks for about 15 years prior to admission; however, the pathogenesis was not clarified in spite of various examinations. Three months prior to admission, left peripheral facial nerve palsy, bilateral hypopion and bilateral hilar lymphadenopathy on plain chest film were noted at the departments of neurosurgery and ophthalmology of our hospital. She was referred and admitted to our ward. The diagnosis of sarcoidosis was made by scalene node biopsy. The syncopal attacks could not be controlled by several anticonvulsant agents. Although no significant findings were observed on brain CT and cerebral angiography, spike wave was revealed on electroencephalography (EEG) in the parieto-temporal lead. The syncopal attacks were diagnosed psychomotor seizures from both the clinical features and the EEG findings. We concluded that syncope was caused by neurosarcoidosis. The patient was prescribed steroid with much improvement of these symptoms.

Adult↗