Biomedical subjects

M Seki

Publications and source records attributed to M Seki.

At least 217 records · Page 12Linked to original sources

PubMed1995

Prediction of pulmonary function after resection of primary lung cancer. Utility of inhalation-perfusion SPECT imaging.

To help determine whether preoperative perfusion and inhalation SPECT imagings are useful in predicting postoperative lung function, Tc-99m MAA perfusion SPECT imaging, CT scans, and pulmonary function tests were prospectively performed in 33 patients with primary lung cancer before and after lobectomy or pneumonectomy. Tc-99m Technegas inhalation SPECT imaging was performed in 6 of 33 patients as well. The authors also studied changes in radioactivity on the operated and nonoperated sides before and after surgery, examined the lowest limit value for adaptability to the operation, and made a comparison of both perfusion and inhalation SPECT imaging. The predicted postoperative values obtained from the preoperative Tc-99m MAA SPECT images correlated more closely with the measured 6-month postoperative values than with the measured 3-month postoperative values. The highest correlation coefficient (r = 0.86) was observed between the predicted forced vital capacity (FVC) value and the measured 6-month postoperative FVC value. In many cases, there was not a great difference between the 6-month and 3-month radioactivity on the operated side obtained from Tc-99m MAA SPECT images. This appears to indicate that pulmonary blood flow on the operated side has completely recovered by 3 months after surgery. However, radioactivity in both the upper and lower lobes of the nonoperated side increased soon after surgery compared with that before the operation, and had not returned to preoperative levels 6 months after surgery. The radioactivity in the right middle lobe did not change before and after surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗

PubMed1995

Therapeutic effects of lansoprazole on peptic ulcers in elderly patients.

We studied the effects of lansoprazole on ulcer healing and Helicobacter pylori infection in elderly patients with peptic ulcers. In a group of 24 patients with gastric ulcers, the H. pylori infection rate was 100%. In the course of gastric ulcer healing with famotidine or lansoprazole alone, the H. pylori infection showed no signs of decline. The ulcer healing rates after 8 weeks were similar between the H2-receptor antagonist famotidine (73%), and the proton pump inhibitor lansoprazole (82%). When eradication of H. pylori infection was attempted by concomitant administration of lansoprazole and amoxicillin 500 mg b.i.d. for 2 weeks, the eradication rate was 33% in the group given lansoprazole 30 mg q.d. plus ampicillin 500 mg b.i.d., whereas it was 77% in the group given lansoprazole 30 mg b.i.d. plus ampicillin 500 mg b.i.d. Lansoprazole is considered to be a useful agent for the treatment of patients with peptic ulcers and H. pylori infection and its effectiveness in H. pylori eradication is improved by b.i.d. administration along with ampicillin.

2-Pyridinylmethylsulfinylbenzimidazoles↗

PubMed1995

Hepatitis C virus core region: helper T cell epitopes recognized by BALB/c and C57BL/6 mice.

In this study, we characterized the B cell and T cell responses to the hydrophilic portion of hepatitis C virus (HCV) core protein in two strains of mice and identified the respective antigen determinants. BALB/c (H-2d) and C57BL/6 (B6:H-2b) mice were immunized by a subcutaneous injection of recombinant HCV core protein together with Freund's complete adjuvant. The level of antibody production, as determined by ELISA, was consistently higher in BALB/c than in B6 mice. However, antibodies in sera from each strain bound to the N-terminal region of the core protein within amino acids 1 to 28 (MSTNPKPQRKIKRNTNRRPQDVKFPGGG), according to an experiment using non-overlapping peptides that covered the hydrophilic portion of HCV core protein. The T cell responses were also higher in BALB/c than in B6 mice with respect to the proliferative responses of the draining lymph node cells in vitro. By limiting dilution cultures of the draining lymph node cells in vitro repetitively stimulated with recombinant core protein, T cell clones were established from both strains of mice and characterized. The surface markers of these clones were Thy-1.2+, CD3+, TCR alpha beta+, CD4+ and CD8+. The proliferative responses were inhibited in the presence of anti-CD4 or anti-MHC class II monoclonal antibodies. The T cell lines in BALB/c mice recognized an epitope in HCV core at amino acids 72 to 91 (EGRAWAQPGYPWPLYGNEGL). The T cell lines in B6 mice recognized an epitope at amino acids 55 to 74 (RPQPRGRRQPIPKARQPEGR). Thus, mice with different MHC haplotypes recognized different non-overlapping T cell antigenic determinants of HCV core proteins.

Amino Acid Sequence↗

PubMed1995

Characterization of DNA synthesis and DNA-dependent ATPase activity at a restrictive temperature in temperature-sensitive tsFT848 cells with thermolabile DNA helicase B.

A temperature-sensitive mutant defective in DNA replication, tsFT848, was isolated from the mouse mammary carcinoma cell line FM3A. In mutant cells, the DNA-dependent ATPase activity of DNA helicase B, which is a major DNA-dependent ATPase in wild-type cells, decreased at the nonpermissive temperature of 39 degrees C. DNA synthesis in tsFT848 cells at the nonpermissive temperature was analyzed in detail. DNA synthesis measured by incorporation of [3H]thymidine decreased to about 50% and less than 10% of the initial level at 8 and 12 h, respectively. The decrease in the level of thymidine incorporation correlated with a decrease in the number of silver grains in individual nuclei but not with the number of cells with labeled nuclei. DNA fiber autoradiography revealed that the DNA chain elongation rate did not decrease even after an incubation for 10 h at 39 degrees C, suggesting that initiation of DNA replication at the origin of replicons is impaired in the mutant cells. The decrease in DNA-synthesizing ability coincided with a decrease in the level of the DNA-dependent ATPase activity of DNA helicase B. Partially purified DNA helicase B from tsFT848 cells was more heat sensitive than that from wild-type cells. Inactivation of DNA-dependent ATPase activity of DNA helicase B from mutant cells was considerably reduced by adding DNA to the medium used for preincubation, indicating that the DNA helicase of mutant cells is stabilized by binding to DNA.

Animals↗

PubMed1995

Determination of interstitial collagenase (MMP-1) in patients with rheumatoid arthritis.

OBJECTIVES: To investigate whether interstitial collagenase (MMP-1) concentration in synovial fluid can be useful as a marker for disease activity in rheumatoid arthritis (RA), to determine the main route by which collagenase degrades the matrix of articular cartilage, and to investigate if an imbalance between metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases (TIMP) is responsible for the activity of MMPs in RA. METHODS: Collagenase concentrations were measured in synovial fluid and paired serum samples using a specific sandwich enzyme linked immunosorbent assay. Collagenase activities were also assayed in synovial fluid samples. Synovial tissues obtained from the same patient were examined by immunohistochemical staining and the numbers of cells expressing collagenase were counted. RESULTS: Collagenase concentrations in synovial fluid did not correlate with C reactive protein and collagenase levels in serum, but did correlate positively with the degree of synovial inflammation, and increased with increasing numbers of cells identified as expressing collagenase in synovial tissue. Collagenase activities did not correlate with TIMP-1 concentrations, but did correlate strongly with the ratios of collagenase concentration to TIMP-1 (r = 0.73). CONCLUSION: The collagenase concentration in synovial fluid cannot be used as a marker for systemic disease activity, but can be used as a marker for the degree of synovial inflammation in the joint from which the sample is aspirated. In advanced RA, most of the collagenase is probably produced in synovial lining cells and released into synovial fluid, where it degrades the matrix of articular cartilage. An imbalance between MMP and TIMP may be of importance in the degradation of extracellular matrix of articular cartilage in RA.

Adult↗

PubMed1995

Expression of streptolysin O gene in Bacillus subtilis.

Streptolysin O (SLO) is a hemolytic, extracellular protein produced by Streptococcus pyogenes. A hybrid gene consisting of the promoter and signal sequence fused to the region encoding the mature sequence of the slo gene was constructed to secrete SLO in Bacillus subtilis. To increase secretion of SLO into the culture supernatant, several SLO expression vectors containing various combinations of promoters and pre-pro sequences were constructed. B. subtilis harboring pPA consisting of the P-43 promoter and the coding sequence of the pre region of the alkaline protease gene that was fused to the pro-mature region of the slo gene secreted SLO into media. The degree of hemolytic activity was found to be about 40-fold higher in the geneticaly engineered B. subtilis strain than that of S. pyogenes. Recombinant SLO was reacted with patients' sera infected by group A streptococci.

Animals↗

PubMed1995

Descending projections from the paraventricular hypothalamic nucleus to the spinal cord: anterograde tracing study in the rat.

We investigated the direct projections from the paraventricular hypothalamic nucleus (PVH) to the spinal cord. When Phaseolus vulgaris leucoagglutinin (PHA-L) was injected into the PVH, labeled descending fibers were observed running bilaterally through three pathways. The first pathway ran into the dorsal longitudinal fasciculus and projected to the central gray matter, Edinger-Westphal nucleus, pedunculopontine tegmental nucleus, nucleus of the locus ceruleus and parabrachial nucleus. The second and third pathways coursed through the medial forebrain bundle, ventral tegmental area, and ventral part of the medulla oblongata. At the medulla oblongata, the second pathway curved dorsolaterally and joined Rexed's lamina V of C1 after giving many projections to the nucleus ambiguus, nucleus of the solitary tract, dorsal motor nucleus of the vagus, and a few to the area postrema. The fibers descended through lamina V until C5, and coursed through lamina I from C6 to the upper coccygeal segments. They gave collateral projections to lamina I from the cervical through the upper coccygeal segments. The third pathway coursed laterally and descended through the lateral funiculus after giving projections to the lateral reticular nucleus and the marginal layer of the spinal trigeminal nucleus. These fibers gave off many projections to the intermediolateral cell column of the thoracic cord and the sacral parasympathetic nucleus. Lamina X received many projections from the fibers of the lateral funiculus at C5 through the b-segment of sacral spinal cord. These results indicate that the PVH may integrate directly with the medullary and spinal autonomic regulatory nuclei, including the vagus complex, sympathetic intermediolateral cell column, laminae I and X, and sacral parasympathetic nucleus.

Animals↗

PubMed1995

[A successfully treated case of thoracoabdominal aortic aneurysm complicated with the coagulation disorder].

We could performed the safe operation for thoracoabdominal aortic aneurysm complicated with pre-DIC. A diagnosis of pre-DIC was made by laboratory data. Low heparin pretreatment was performed for the short term because we presumed the cause for pre-DIC was thromboses in aneurysm. That treatment was effective for the temporal remission of pre-DIC. In addition, during partial ECC low heparin (1 mg/kg) and nafamostat mesilate (2 mg/kg/h) were used. As a result, during and after the operation blood loss was a little. In summary heparin pretreatment is useful therapy for DIC and pre-DIC in aortic aneurysm patients.

Aged↗

PubMed1995

In vivo transfection of hepatitis C virus complementary DNA into rodent liver by asialoglycoprotein receptor mediated gene delivery.

An in vivo model of hepatitis C virus (HCV) infection is needed to enable investigation of the mechanism of the liver injury that it causes. In this study, we used asialoglycoprotein receptor mediated gene delivery to obtain expression of the complementary DNA (cDNA) coding the core and part of the envelope 1 protein of HCV because selective delivery to the hepatocytes has been reported to be attained with this method. The optimum carrier-DNA ratio was examined using in vitro transfection and found to be important for the efficiency of this method. In transfection in vivo, microautoradiographical examination showed that the transfected plasmids were delivered selectively to the liver parenchymal cells. To obtain an immunohistochemically detectable level of protein expression in rodent liver, some modifications for increasing the in vivo transfection efficiency were performed; a lysosomal enzyme inhibitor, chloroquine, was used and the administration route of the carrier-DNA complex was changed from the tail vein to the portal vein. On the bases of these results, in vivo transfection with expression vector of HCV core/E1 region was performed. In rat liver transfected by intraportal injection with chloroquine, the transcript RNA and the core protein were detected. These results indicated that the HCV core/E1 expression vector was not merely delivered but also successfully expressed in the liver using asialoglycoprotein receptor mediated gene delivery. The number of the HCV core expressing cells in the transfected liver was similar to that in patients with hepatitis C. These in vivo transfected animals should be useful for investigating the role of this region in the liver injury caused by HCV.

Animals↗

PubMed1995

[Coronary risk index for pre-operative evaluation of ischemic heart disease].

The incidence of ischemic heart disease is increasing in Japan, and we often experience perioperative management of patients with coronary arterial stenosis. It is, however, difficult to evaluate the lesion of coronary arterial stenosis. We devised a coronary risk index (CRI), which is a scoring system and can easily predict the coronary arterial stenosis from the preoperative routine examination and the patients data. The patients with high CRI have a high risk of ischemic heart disease. By carefully managing these patients from this information, we can decrease the incidence of perioperative complications resulting from ischemic heart disease.

Adult↗

PubMed1995

[Primary hemangiopericytoma of the chest wall: a case report].

We describe a rare male case of malignant hemangiopericytoma of the chest wall. An extrapleural chest wall mass about 1.5 x 4 cm in size was detected along the right 3rd rib on a chest roentgenogram when the patient was 58 years old. The tumor did not enlarge for over 12 years thereafter. At the age of 73 years, the patient came to our hospital for chest pain after a traffic accident. A roentgenogram revealed the extrapleural tumor of the chest, which was enlarged to 8 x 12 x 7 cm, and right hemothorax. The tumor was resected together with the 3rd and 4th ribs. Light and electron microscopy and immunostaining studies led to a diagnosis of malignant hemangiopericytoma. The postoperative course was uneventful, and radiotherapy and chemotherapy were performed. The patient has been well without recurrence for 18 months after the operation. We also reviewed 9 cases of this tumor reported in Japan.

Aged↗

PubMed1995

[A case report of pulmonary sequestration (Pryce I) associated with incomplete lobulation of the left lung].

A 28-year-old man was treated surgically for pulmonary sequestration of Pryce type I associated with incomplete lobulation of the left lung. His chief complaint was hemoptysis. His chest X-ray film showed a mass lesion behind the cardiac shadow. Aortogram revealed a large artery arising from the descending aorta and supplying the left basal segment, and venous blood returning into the left inferior pulmonary vein. The left basal segment had no pulmonary arteries. A bronchogram showed no defects in the bronchial tree. The left basal segment was resected successfully. Histological study showed the trunk of the aberrant artery to be elastic. Differences between histological types of aberrant arteries in pulmonary sequestration of Pryce type I and the pathogenesis of intralobar sequestration were discussed.

Adult↗

PubMed1995

Experimental study on safety for granulopoiesis in simultaneous therapy with recombinant human granulocyte colony-stimulating factor and chemotherapy.

Since recombinant human granulocyte colony-stimulating factor (rhG-CSF) recruits hematopoietic progenitor cells into the cell cycle, the possibility remains that simultaneous injection of rhG-CSF and chemotherapeutic agents may aggravate the chemotherapy-induced neutropenia by sensitizing normal progenitor cells to the cytotoxic effects of chemotherapeutic agents. Therefore, the use of rhG-CSF is usually restricted from the day after chemotherapy. In the present study, we investigated whether concurrent treatment with rhG-CSF and chemotherapeutic agents aggravated granulopoietic failure, using murine neutropenic models. Neutropenia induced by a single injection of cyclophosphamide, mitomycin C, adriamycin, vincristine, combination of mitomycin C+vincristine, or combination of cyclophosphamide+vincristine+adriamycin (CHOP) was not aggravated by simultaneous injection of rhG-CSF (30 micrograms/kg, SC). In contrast, a single concurrent injection of rhG-CSF and 5-fluorouracil aggravated the neutropenia and the decrease in marrow colony-forming unit-granulocyte/macrophage counts, but simultaneous and following injections of rhG-CSF enhanced the recovery of neutrophils. Moreover, neutropenia induced by successive treatment with cisplatin was prevented by concurrent treatment with rhG-CSF during the period of the chemotherapy. From these results, concurrent treatment with rhG-CSF and chemotherapeutic agents with the exception of 5-fluorouracil may be feasible and well-tolerated in clinical use.

Animals↗

PubMed1995

[Matrix metalloproteinase (MMP-9) in patients with rheumatoid arthritis].

MMP-9 degrades type IV collagen, gelatin, type V collagen, and type XI collagen. We measured proMMP-9 and proMMP-9/TIMP-1 complex in sera and joint fluids by sandwich ELISA, and examined immunohistochemically the expression of these proteins in joint tissue from patients with rheumatoid arthritis (RA). ProMMP-9 was purified by the three chromatographic steps from the culture medium of HT1080 cells. Purified proMMP-9 and activated MMP-9 by APMA showed a single band of Mr92000, Mr67000, resectively on gelatin-zymography. We raised two monoclonal antibody colones 2G9, 8G7 against proMMP-9 with BALB/c mice. 2G9 and 8G7 reacted with proMMP-9 on Western blotting, and these clones reacted proMMP-9 and proMMP-9/TIMP-1 complex on sandwich ELISA, specifically. ProMMP-9 concentration in 86 sera (749.4+/-940.2 ng/ml) and 54 joint fluids (4539.9+/-7681.5 ng/ml) from patients with RA was significantly higher than those of patients with osteoarthritis and control. Immunohistochemistry with 2G9 showed that in rheumatoid synovium proMMP-9 localized in neutrophils and monocytes diffusely infiltrated the sublining layer. In addition, osteoclasts in rheumatoid subchondral bone were intensively stained. ProMMP-9 concentration in joint fluids from 39 RA patients was not correlated to stage and class of Steinbrocker and to clinical laboratorial data. But, it was positively correlated to the number of proMMP-9 positive cells in RA synovium (r=0.607) and the score of Roony's diffuse infiltrates of lymphocytes (r=0.720). Our results suggest a role of MMP-9 in joint destraction of RA throughout neutrophils and monocytes, and a regulation of this enzyme by lymphocytes.

Adult↗

PubMed1994

Molecular cloning of cDNA encoding human DNA helicase Q1 which has homology to Escherichia coli Rec Q helicase and localization of the gene at chromosome 12p12.

A complementary DNA encoding DNA-dependent ATPase Q1 possessing DNA helicase activity, which is the major DNA-dependent ATPase in human cell extracts, was cloned from a cDNA library of human KB cells. The predicted amino acid sequence has seven consecutive motifs conserved in the RNA and DNA helicase super family and DNA helicase Q1 belongs to DEXH helicase family. A homology search indicated that helicase Q1 had 47% homology in the seven conserved regions with Escherichia coli RecQ protein. Three RNA bands of 4.0, 3.3, and 2.2 kilobases were detected in HeLa cells by Northern blotting. Analysis of the genomic DNA indicated the presence of a homologous gene in mouse cells. The DNA helicase Q1 gene was localized on the short arm of human chromosome 12 at 12p12.

Adenosine Triphosphatases↗

PubMed1994

[Promotive effect of recombinant human granulocyte colony-stimulating factor (rhG-CSF) on recovery from neutropenia induced by fractionated irradiation in mice].

The effect of recombinant human granulocyte colony-stimulating factor (rhG-CSF) on the recovery from neutropenia induced by fractionated whole-body irradiation was investigated in mice. Male 7-week old C3H/HeN mice received a total of ten exposures of 0.25 Gy/day from day 1 to 5 and from day 8 to 12. Peripheral neutropenia with a nadir on day 17 was caused by the fractionated irradiation. Daily subcutaneous injections of rhG-CSF at 0.25 and 2.5 micrograms/body/day from day 1 to 21 promoted the recovery of neutrophils in a dose-dependent manner. The kinetics of morphologically identifiable bone marrow cells were studied to clarify the mechanism behind the promotive effect of this factor. A slight decrease in mitotic immature granulocytes, such as myeloblasts, promyelocytes and myelocytes on day 5, and a drastic decrease in metamyelocytes and marrow neutrophils on days 5, 9, and 17 were seen in the femur of irradiated mice. Treatment using rhG-CSF caused an increase in immature granulocytes of all differential stages in the femur. Microscopic findings of the femurs and spleens also revealed an increase in immature granulocytes in these organs in mice injected with rhG-CSF. These results indicate that rhG-CSF accelerates granulopoiesis in the femur and spleen, thereby promoting recovery from neutropenia induced by fractionated irradiation.

Animals↗

PubMed1994

[Analysis of three-dimensional imaging of the right hepatic vein and right portal vein branch using 2D-TOF MR angiography: evaluation of utility of MR angiography in determining puncture course on TIPS].

2D-TOF MR angiographies were performed in seven patients of liver cirrhosis with hepatocellular carcinoma to investigate three-dimensional anatomical relationships of the right hepatic vein and first order of right portal vein branch. The puncture course was set up in three-dimensional rectangular coordinates, and the bend angle and turning angle of the modified Ross needle, and puncture distance were calculated of the data measured on the A-P and L-R projection images of MR angiograms. The utility and limitation of 2 D-TOF MR angiography to determine the puncture course on TIPS were discussed in this study.

Adult↗

PubMed1994

Purification of two DNA-dependent adenosinetriphosphatases having DNA helicase activity from HeLa cells and comparison of the properties of the two enzymes.

DNA-dependent ATPase activities in crude extracts prepared from HeLa cells were separated into five peaks designated Q1 to Q5 by FPLC Mono Q column chromatography. In our previous study, we observed that crude extracts prepared from xeroderma pigmentosum complementation group C (XP-C) cells contained no DNA-dependent ATPase activity at the peak position of Q1 and exhibited a broader peak with higher activity than normal Q2 at the peak position of Q2 [Yanagisawa, J., Seki, M., Ui, M., & Enomoto, T. (1992) J. Biol. Chem. 267, 3585-3588]. We have purified two DNA-dependent ATPases Q1 and Q2 from HeLa cells and characterized their properties in order to obtain a means to discriminate ATPase Q1 from Q2 in XP-C cells. The apparent molecular masses of Q1 and Q2 on SDS-polyacrylamide gel electrophoresis were 73 and 100 kDa, respectively. The two enzymes required a divalent cation for activity. DNA-dependent ATPase Q1 hydrolyzed ATP and dATP and Q2 hydrolyzed ATP preferentially among the nucleotides tested. Both enzymes preferred single-stranded DNA as a cofactor. The DNA-dependent ATPase activity of Q2 was inhibited by 90% in the presence of 200 mM NaCl, whereas that of Q1 was not affected by NaCl at concentrations up to 200 mM. Both enzymes had DNA helicase activity, that of Q1 being more resistant to NaCl than that of Q2. The DNA helicase activity of Q2 was about 150-fold higher than that of Q1, when compared with units of ATPase activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphatases↗