Biomedical subjects

T Tsuji

Publications and source records attributed to T Tsuji.

At least 451 records · Page 25Linked to original sources

PubMed1997

[Intraoperative radiotherapy combined with extended resection for pancreatic cancer].

Since 1984, intraoperative radiotherapy combined with extended resection for pancreatic cancer has been performed in our clinic to prevent local recurrence. Following extended resection, a dose of 30 Gy of 9-12 MeV electrons was administered to the operative field including the paraaortic area from the diaphragm above to the inferior mesenteric artery below. Results of the combined therapy of 35 patients were compared to results of 11 patients who underwent extended resection alone. The combined therapy group compared to extended resection alone group showed improvement in the survival rate. It's 5 year survival rate was 16.8% in all the 35 cases, 22.3% in patients who had macroscopic tumor clearance and 18.9% in patients with Stage IVa tumour according to The Japanese classification. In autopsies of 10 cases who underwent the combined therapy, only 4 had local recurrence enclosed by thick, firm connective tissue. There was no any local recurrence in 2 cases who underwent non curative resection. Enhanced local control induced by the combined therapy, however, only has a limited impact on overall survival, because of system disease progression, especially hepatic metastases. These results suggest that combination of IORT and extended resection should be performed on selected patients to control local recurrence and anticancer treatment for metastases of the liver must be established for the cure of pancreatic cancer as soon as possible.

Combined Modality Therapy↗

PubMed1997

[Numerical aberration of chromosome 17 is correlated with multiple primary cancer in colorectal carcinoma].

Numerical aberration of chromosome 17 of 14 cases of colorectal carcinoma with multiple primary cancer (: multiple cancer) was compared with that of 35 cases of colorectal carcinoma without any other cancer (: single cancer). Fluorescence in situ hybridization with p17H8 was performed on touch smear from fresh materials. The proportion of aneusomy 17 (NCAI: numerical chromosome aberration index) in multiple cancers was significantly higher than that of single cancers (37.7 +/- 10.5% VS 46.1 +/- 8.0%; p < 0.01). Although NCAI of single cancers conformed to cancer progression (26.1 +/- 4.7% in Dukes A, 33.1 +/- 7.1% in Dukes B, 39.9 +/- 6.9% in Dukes C, and 45.7 +/- 12.0% in Dukes D), that of multiple cancers was high in all stages (44.7 +/- 7.3%, 44.4 +/- 6.8%, 50.4 +/- 11.2%, and 49.6 +/- 5.6%, respectively). Furthermore, the multiple numerical aberration of chromosome 17 in multiple cancers was more often than that of single cancers (64.3% VS 22.9%; p < 0.01).

Aged↗

PubMed1997

[Effects of pimobendan on pulmonary hypertension in patients with chronic pulmonary emphysema].

Pimobendan is a positive inotropic agent that dilates blood vessels and sensitizes the myocardium to calcium. We studied the clinical usefulness of single oral doses of pimobendan (2.5 mg) in 8 patients with pulmonary hypertension caused by chronic pulmonary emphysema. We measured the short-term effects of pimobendan on pulmonary hemodynamics and gas exchange. Pimobendan significantly decreased mean pulmonary artery pressure from 23.4 +/- 3.4 to 18.5 +/- 2.5 mmHg, and total pulmonary resistance from 383 +/- 111 to 281 +/- 81 dyne.sec.cm-5, while oxygen delivery and cardiac output increased significantly (oxygen delivery: from 81.8 +/- 10.2 to 93.5 +/- 16.2 ml O2/min. cardiac output: from 4.98 +/- 0.76 to 5.77 +/- 1.49 l/min, means +/- SD). Systemic vascular resistance was not significantly reduced. The ratio of pulmonary to systemic vascular resistance was reduced, but not significantly. Arterial oxygen tension (PaO2) and arterial carbon dioxide tension (PaCO2) did not change significantly. These results indicate that pimobendan may be useful in the treatment of patients with secondary pulmonary hypertension.

Aged↗

PubMed1997

Triple extramammary Paget's disease.

BACKGROUND: Triple extramammary Paget's disease (TEPD) has been considered to be rare in the English literature, and its incidence and characteristics are unclear. There are many therapeutic options for treating extramammary Paget's disease (EPD). OBJECTIVE: Our purpose was to investigate how many TEPD cases have been reported previously and to describe their characteristics. We also describe the effectiveness of radiotherapy for them. METHODS: We report two TEPD cases, and summarize previously reported TEPD cases together with our cases. RESULTS: Twenty-three TEPD cases have been reported previously. Of these, 19 cases have been in Japan. All but one patient with TEPD were male. Their axillary lesions often showed no eruptions or very slight erythema. Radiotherapy for our cases was effective although the effectiveness of radiotherapy is controversial. CONCLUSION: In genital Paget's disease bilateral axillae should be examined histologically, even if they show no or slight eruptions. Radiotherapy may be useful for EPD, particularly axillary Paget's disease.

Aged↗

PubMed1997

[Flow cytometric quantification of numerical chromosome aberrations in non-small cell lung carcinomas using formalin-fixed paraffin-embedded tissue].

Fluorescence in situ hybridization with biotinylated repetitive DNA probe specific for the centromeric region of chromosome 17 (p17H8: Oncor) was applied to suspended nuclei which were isolated by Shutte's method from formalin-fixed paraffin-embedded tissue. The tissues were obtained from surgically resected specimens from nine patients with non-small cell lung carcinoma. The isolated nuclei were prepared with 0.05% pepsin/0.1NHCl for 15 minutes at 37 degrees C. Subsequently, these were immersed in 70% acetic acid for 10 seconds at room temperature. After heat denature with hybridization mixture which contained 3 mu 1 DNA probe for 10 minutesat 70 degrees C, 1 x 10(6) nuclei were incubated overnight at 37 degrees C. After washing with 60% formamide/2 x SSC, the hybridized probes were labeled by FITC conjugated avidin. A number of centromeric signals of chromosome 17 wasevaluated by fluorescence microscopy (BH-2, Olympus). Furthermore, a probe-related FITC intensity was quantified using flow cytometry (FACScan, Becton Dickinson). As the results, there was good correlation between a relative fluorescence intensity determined by flow cytometry and a relative fluorescence signal by fluorescence microscopy (p < 0.05).

Aged↗

PubMed1997

[Cell-biological changes on the disordered tissues].

In this study, we investigated cell-biologically the cell death generating by injuries, on the basis of two mechanisms of the cell death, these are necrosis and apoptosis. To heat the liver of rats, a heat device having a PID built-in electron regulator system was newly developed by us. The liver of rats laparotomized under anesthesia was heated at 37 degrees C, 50 degrees C and 65 degrees C for 5 min with a heated needle connected to the device, and thereafter the rats were survived in the given time. Appearance of the cell death in the tissue injured by heat was analyzed, in progress of the survival time, by means of staining of the tissue with hematoxylin-eosin (HE) and TUNEL method and agarosegel electrophoresis of DNA extracted from the tissue injured. Consequently, apoptosis appeared, in all heat temperatures, with bimodal pattern showing peak at about 2 and 10 hours after heat. Apoptosis in the first peak dottedly appeared, in heat temperature at 37 degrees C, in the whole region affected by heat. When the liver was heated at 50 degrees C and 65 degrees C, it first appeared on outer edge in the region affected by heat, and then made progress to the center of the region, condensation of chromatin was, in HE staining, remarkable at border between the injured and normal tissues. These findings were different from those in 37 degrees C. It seems that apoptosis in the first peak is caused by direct action of temperature. In the same time as the first peak of spoptosis appeared, appearance of HSP (heat shock protein) was observed. Apoptosis in the second peak, in all heat temperature, made progress from outer edge of the injured region to the center, time course of progression of the apoptosis was almost concurrent with that of infiltration of neutrophil to the injured region. Ladder formation was observed, when DNA extracted from the tissue showing apoptosis was applied for agarosegel electrophoresis. Necrosis in the injured tissue appeared in the same pattern with appearance of apoptosis in time course and on location, necrosis and apoptosis were observed in almost same degree up to appearance of the second peak of apoptosis. After 24 hours of heat, apoptotic cells were phagocytosed, only necrotic tissue remained. It seems that appearance of necrosis and apoptosis is caused by action of TNF alpha derived from neutrophils, since generation of TNF alpha was confirmed electron microscopically. In this study, it became cell-biologically evident that apoptosis is intensely concerned with cell death in the injured tissue.

Animals↗

PubMed1997

Characterization and transplantation of agarose microencapsulated canine islets of Langerhans.

The bioartificial pancreas was designed to incorporate islet tissues and a selectively permiable membrane that isolates islets from the immune system of the recipient. The efficacy of agarose, a nontoxic polysaccharide, has been evaluated as a material of microcapsules to prevent allo- and xenograft rejection in rodents. The aim of this study is to demonstrate the possibility of the agarose microcapsule containing allo-islets as a bioartificial pancreas in canine model. In vitro viability of islets was determined by glucose challenge during perifusion experiments (n = 4). Insulin secretion from both encapsulated (enc.) and non-encapsulated (non-enc.) canine islets rose from initial basal levels of 0.09 (encap.), 0.07 (non-encap.) to the peak of 0.2 (encap.), 0.1 (non-encap.) in microU/islet/min after 5 minutes, then decreased to the basal level when the glucose challenge was discontinued. Auto-transplantation was performed in two dogs to evaluated in vivo viability and biocompatibility of encapsulated islets implanted into the splenic sinus by venouse reflux. Two weeks after auto-transplantation, the plasma insulin levels in the splenic vein and artery of two dogs were assayed. In the first dog, serum insulin level was 1 microU/ml both in the vein and the artery and increased, after glucagon (1.0 mg) injection, to levels of 9 microU/ml in the vein, but still kept 1 microU/ml in artery, as well as in the second one. Histological and electron-microscopical examination of the spleen revealed that encapsulated islets remained morphologically intact and the surface of agarose capsules showed no significant adherence of fibroblasts and inflammatory cells. Functional efficacy of the microencapsulated islets was determined using five totally-pancreatectomized diabetic dogs as recipients without immunosuppression. Defined quantity of microencapsulated islets from outbred mongrel donors were grafted through the catheter into omental tissue of the pancreatectomized recipients. All dogs had various degrees of reduced insulin requirements. In three of five recipients, the average fasting glucose values were controlled under 120 mg/dl for 28, 42, 49 days without exogenous insulin, which received totally 4.3 x 10(3), 7.3 x 10(3) and 1.0 x 10(4) (IE/kg) of microencapsulated islets, respectively. In conclusion, the present study indicates that the agarose-based microencapsulated islets can function in large diabetic animals, resulting in the independence of exogenous insulin therapy for prolonged periods without the need for immunosuppression.

Animals↗

PubMed1996

Role of the V2, V3, and CD4-binding domains of GP120 in curdlan sulfate neutralization sensitivity of HIV-1 during infection of T lymphocytes.

A sulfated polysaccharide, curdlan sulfate (CRDS) with 1,3-beta-D-glucan as a main chain, inhibits HIV-1 infection of human peripheral blood lymphocytes (PBLs) by binding to the V3 region of gp 120. We previously showed that T cell (T)-tropic HIV-1 isolates are over 10-fold more sensitive to neutralization by CRDS than macrophage (MT)-tropic viruses, which possesses a relatively less charged amino acid composition in the V3 sequence. To analyze the interaction of CRDS with V3 and its association with neutralization sensitivity of HIV-1 isolates, we examined the effect of CRDS on the binding of neutralizing antibodies to monomeric and oligomeric gp 120 mutants of T- and MT-tropic HIV-1 clones in which the V3 loop was either deleted or substituted by V3 of another isolate. Our results showed that the presence and the amino acid composition of the V3 loop appears to determine the extent of interaction of CRDS with the V2 and CD4-binding regions on native gp 120 monomers; however, the positive charge of V3 has less effect on this interaction on oligomeric gp 120. Furthermore, our results established that only the CRDS-induced masking of V3 on oligomeric gp120 appears to be associated with the anti-HIV-1 activity of CRDS in vitro. Our findings underline the usefulness of CRDS for understanding the structural constraints on gp 120 that drive the transition from MT- to T-tropic isolates in vivo and enable the virus to use multiple fusion cofactors.

Amino Acid Sequence↗

PubMed1996

Three-dimensional labeling program for elucidation of the geometric properties of biological particles in three-dimensional space.

For all biological particles such as cells or cellular organelles, there are three-dimensional coordinates representing the centroid or center of gravity. These coordinates and other numerical parameters such as volume, fluorescence intensity, surface area, and shape are referred to in this paper as geometric properties, which may provide critical information for the clarification of in situ mechanisms of molecular and cellular functions in living organisms. We have established a method for the elucidation of these properties, designated the three-dimensional labeling program (3DLP). Algorithms of 3DLP are so simple that this method can be carried out through the use of software combinations in image analysis on a personal computer. To evaluate 3DLP, it was applied to a 32-cell-stage sea urchin embryo, double stained with FITC for cellular protein of blastomeres and propidium iodide for nuclear DNA. A stack of optical serial section images was obtained by confocal laser scanning microscopy. The method was found effective for determining geometric properties and should prove applicable to the study of many different kinds of biological particles in three-dimensional space.

Animals↗

PubMed1996

Genetic organization and diversity of the 3' noncoding region of the hepatitis C virus genome.

The 3' noncoding region (3' NCR) of the hepatitis C virus (HCV) genome contained in viral particles was analyzed by an RNA linker ligation followed by reverse transcription-polymerase chain reaction. Sequence analysis of the amplified fragment from four strains, including different genotypes 1b, 2b, 3a, and 3b indicated that the 3' NCR is composed of between 200 and 235 nts. The sequence of the 3' NCR consists of a type-specific region (immediately following the termination codon), a poly(U) stretch, a C(U)n-repeat, and highly conserved region termed the core element. The poly(U) stretch and C(U)n-repeat regions varied in length and in sequence among different genotypes. Core elements having putative secondary structure consisted of 98 or 100 nts and were highly conserved in all genotypes. Most of the nt changes found in different genotypes did not affect the secondary structure of the core elements, suggesting that this region may play an important role in replication, stabilization of the HCV RNA, and/or packaging of the genome. Most of the HCV-1b strains carried two U residues at the 3' end of the core element, while the minor HCV-1b strains had no U residues, demonstrating that there are two variants in type 1b strains. Amplification of the core element using linker-primed cDNA was comparable with that using the 3' proximal core element-primed cDNA, indicating that the 3' end of HCV genome was terminated by an OH group.

Base Sequence↗

PubMed1996

2B1 antigen characteristically expressed on extracellular matrices of human malignant tumors is a large chondroitin sulfate proteoglycan, PG-M/versican.

2B1 is a monoclonal antibody against a large proteoglycan isolated from human yolk sac tumor (M. Sobue et al., Histochem. J., 21: 455-460, 1989). The antigen is expressed in a variety of embryonal tissues as well as most if not all malignant tumor tissues. However, the expression in normal adult tissues is limited to some tissues, such as the smooth muscle layers of the aorta. We characterized the 2B1 antigen isolated from the conditioned medium of human malignant fibrous histiocytoma and found that immunological and biochemical properties are identical to those of a large chondroitin sulfate proteoglycan, PG-M/versican. Partial amino acid sequences of peptides obtained from the core protein by V8 protease digestion and subsequent SDS-PAGE were detected in the reported amino acid sequence of human PG-M/versican with a complete identity. Furthermore, 2B1 was distinctly reactive to the expressed protein by transfection of the cDNA for the shortest form into mouse cells. The results indicate that the antigen is the PG-M core protein, and the epitope may be in one of the globular domains. It is thus likely that PG-M/versican is one of the extracellular matrix components characteristic of human malignant tumors.

Amino Acid Sequence↗

PubMed1996

Telomerase as a tool for the differential diagnosis of human hepatocellular carcinoma.

BACKGROUND: Telomerase activation is thought to be essential for the immortality of cancer cells. We measured telomerase activity in human liver samples, including hepatocellular carcinoma (HCC), and evaluated this assay as a tool for the diagnosis of HCC using 21-gauge (21-G)-needle biopsy specimens. METHODS: Ninety-four liver samples (27 HCC, 27 liver cirrhosis, 37 chronic hepatitis, and 3 normal liver) that were surgically resected or biopsied with a 12-gauge Silverman needle and 13 HCC samples that were biopsied with a 21-G needle were analyzed for telomerase activation. RESULTS: Eleven of 29 (38%) tumor-bearing liver samples were weakly telomerase-positive, whereas telomerase activity was observed infrequently in nontumor-bearing liver samples (6 of 35; 17%) and in normal liver samples (0 of 3; 0%). The positivity of surgical samples for well differentiated, moderately differentiated, and poorly differentiated HCC was 88% (7 of 8), 87% (13 of 15), and 0% (0 of 2), respectively. In telomerase-positive HCC, 43% (3 of 7) of well differentiated samples were weakly positive, whereas 92% (12 of 13) of moderately differentiated samples were strongly positive. The difference in the tumor sizes and viral marker status did not affect the activity. The telomerase activity of the 21-G-needle biopsied specimens showed no significant difference from that of the surgical samples. The positive incidence of 21-G specimens was 80% (8 of 10) and 100% (2 of 2) in well differentiated HCC and moderately differentiated HCC, respectively. CONCLUSIONS: An incremental positivity of telomerase was observed during hepatocarcinogenesis. The use of this assay in 21-G-needle biopsy specimens may be useful in clinical examination.

Adolescent↗

PubMed1996

Novel monoclonal antibody, SO-MU1, against human gastric MUC5AC apomucin.

Human gastric mucins were chemically deglycosylated with trifluoromethanesulfonic acid. A mouse monoclonal antibody (MoAb), SO-MU1, was established against the deglycosylated mucins. SO-MU1 recognized not only the deglycosylated mucins but also the native gastric mucins. Periodate treatment of the native mucins increased the SO-MU1 reactivity. Trypsin digestion abolished the antigenicity. Human gastric cDNA expression library was screened with SO-MU1 and a mucin cDNA clone was obtained. Its sequence contained the MUC5AC tandem repeat domain. We studied gastrointestinal distribution of the SO-MU1-reactive antigen immunohistochemically. Gastric surface epithelial cells and parietal cells expressed the antigen, but the glandular cells did not. The antigen was also detected in the small intestine and biliary tract but not in the colon and pancreas. In summary, (1) MoAb SO-MU1 was raised against human gastric mucins, (2) it recognized human gastric MUC5AC apomucin, and (3) the SO-MU1-reactive antigen showed characteristic distribution in the organs of endodermal origin. MoAb SO-MU1 is the first MoAb against MUC5AC.

Amino Acid Sequence↗

PubMed1996

Mutation in p53 and de-regulation of p53-related gene expression in three human cell lines immortalized with 4-nitroquinoline 1-oxide or 60Co gamma rays.

In vitro models of malignant transformation of human cells may provide considerable insight into the mechanisms of multi-step carcinogenesis. It is well established that normal human cells must be immortalized before they can be malignantly transformed; however, they are stringently destined for aging and are rarely immortalized. The mechanism of cellular aging and immortalization is still unknown. We detected expression of only mutated p53 mRNA by direct sequencing of the reverse-transcribed mRNA in 3 human cell lines immortalized either with 4-nitroquinoline 1-oxide or with 60Co gamma rays. Consequently, only the mutated pS3 protein was expressed in each immortalized cell line. The expression of sdiI/p21 and mdm2, both of which are positively regulated by wild-type p53, was significantly down-regulated in the immortalized cell lines, resulting in over-expression of cdk2 and cdk4. Introduction of the sdiI/p21 gene into these cells was followed by a remarkable decrease in their ability to synthesize DNA. These results indicate that the p53 cascade may play an important role in the immortalization of human cells.

4-Nitroquinoline-1-oxide↗

PubMed1996

A mutation in endothelin-B receptor gene causes myenteric aganglionosis and coat color spotting in rats.

Congenital aganglionosis rat (AR) is a mutant with an autosomal recessive gene (sl), which shows megacolon caused by the absence of myenteric ganglion cells and white coat-color with a small pigmented spot on the head. Recently, targeted disruption of the endothelin-B (ETB) receptor gene (EDNRB) in the mouse has been reported to cause aganglionic megacolon and coat color spotting resembling the phenotypes of the sl/sl rats. To identify the mutation responsible for the phenotypes of the sl/sl rats, we determined the nucleotide sequences of the EDNRB genes of the sl/sl rats and found that a 301-bp region intervening between direct repeat sequences was deleted in the EDNRB gene, and the deletion produces various transcripts due to aberrant splicing.

Animals↗

PubMed1996

Suppressive effect of N-(benzyloxycarbonyl)-L-phenylalanyl-L-tyrosinal on bone resorption in vitro and in vivo.

The suppressive effect of N-(benzyloxycarbonyl)-L-phenylalanyl-L-tyrosinal on bone resorption was examined in vitro and in vivo. This synthetic peptidyl aldehyde was found to be a potent and selective cathepsin L inhibitor in our screening for cysteine protease inhibitors. In the pit formation assay with unfractionated rat bone cells, 1.5 nM of this compound markedly inhibited parathyroid hormone-stimulated osteoclastic bone resorption. In addition, intraperitoneal administration of this peptidyl aldehyde (2.5-10 mg/kg) for 4 weeks suppressed bone weight loss dose dependently in the ovariectomized mouse, experimental model of osteoporosis. Hydroxyproline measurement of the decalcified femurs from these ovariectomized mice suggested that this compound acts as a bone resorption suppressor through the inhibition of collagen degradation.

Animals↗

PubMed1996

Engineering specificity for folate into dihydrofolate reductase from Escherichia coli.

Despite several similarities in structure and kinetic behavior, the bacterial and vertebrate forms of the enzyme dihydrofolate reductase (DHFR) exhibit differential specificity for folate. In particular, avian DHFR is 400 times more specific for folate than the Escherichia coli reductase. We proposed to enhance the specificity of the E. coli reductase for folate by incorporating discrete elements of vertebrate secondary structure. Two vertebrate loop mutants, VLI and VLII containing 3-7 additional amino acid insertions, were constructed and characterized by using steady-state kinetics, spectrofluorimetric determination of ligand equilibrium dissociation constants, and circular dichroism spectroscopy. Remarkably, the VLI and VLII mutants are kinetically similar to wild-type E. coli reductase when dihydrofolate is the substrate, although VLII exhibits prolonged kinetic hysteresis. Moreover, the VLI dihydrofolate reductase is the first mutant form of E. coli DHFR to display enhanced specificity for folate [(kcat/Km)mutant/(kcat/Km)wt = 13]. A glycine-alanine loop (GAL) mutant was also constructed to test the design principles for the VLI mutant. In this mutant of the VLI reductase, all of the residues from positions 50 to 60, except the strictly conserved amino acids Leu-57 and Arg-60, were converted to either glycine or alanine. A detailed kinetic comparison of the GAL and wild-type reductases revealed that the mutations weaken the binding by both cofactor and substrate by up to 20-fold, but under saturating conditions the enzyme exhibits a kcat value nearly identical to that of the wild type. The rate of hydride transfer is reduced by a factor of 30, with a compensating increase in the dissociation rate for tetrahydrofolate. Although key stabilizing interactions have been sacrificed (it shows no activity toward folate), the maintenance of the correct register between key residues preserves the activity of the enzyme toward its natural substrate. Collectively, neither specific proximal point site mutations nor larger, more distal secondary structural substitutions are sufficient to confer a specificity for folate reduction that matches that observed with the avian enzyme. This is consistent with the hypothesis that the entire protein structure must contribute extensively to the enzyme's specificity.

Amino Acid Sequence↗

PubMed1996

Persistence of hepatitis C virus RNA in established human hepatocellular carcinoma cell lines.

The persistence of the viral RNA of hepatitis C virus (HCV) was examined in 13 hepatocellular carcinoma (HCC) and two hepatoblastoma cell lines by reverse transcription followed by the polymerase chain reaction (RT-PCR). HCV RNA was detected in three HCC lines (JHH-1, JHH-4, and JHH-6) and negative-strand viral RNA was found in JHH-4, indicating that there is a putative replicative intermediate of HCV in JHH-4 cells. To rule out the possibility of contamination, the partial nucleotide sequences of HCV-specific PCR products of these three cell lines were determined. The clone from JHH-1 belonged to genotype 1 (1a or 1b), and the clones from JHH-4 and JHH-6 belonged to genotype 2b, but their sequences differed from each other. These cell lines may be useful for studies related to HCV.

Adolescent↗