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Biomedical subjects

Y Kawarada

Publications and source records attributed to Y Kawarada.

At least 73 records · Page 4Linked to original sources
PubMed1998

Molecular cloning and characterization of human PDE8B, a novel thyroid-specific isozyme of 3',5'-cyclic nucleotide phosphodiesterase.

We have identified a novel human isozyme of 3',5'-cyclic nucleotide phosphodiesterase (PDE), which we designated PDE8B. cDNA of 2844 bp encoding the C-terminal 659 amino acids of PDE8B was cloned following the identification of an expressed sequence tag (EST) obtained through a search of the EST database. The predicted protein sequences of PDE8B showed highest homology (65% identity, 83% similarity) to that of PDE8A. Northern blot analysis indicated that the mRNA encoding PDE8B is expressed specifically and abundantly in thyroid gland as a approximately 4.2 kb mRNA, in contrast to the wide expression of PDE8A mRNA in various tissues. The carboxyl-terminal 584 amino acids of PDE8B were expressed in E.coli as a fusion protein. The recombinant PDE8B exhibited cAMP PDE activity which was not inhibited by various PDE inhibitors including vinpocetine, milrinone, rolipram, and IBMX with the exception of dipyridamole which caused 50% inhibition at a concentration of 40 microM. cAMP hydrolytic activity was unaffected by cGMP and no cGMP PDE hydrolysis were detectable at concentrations up to 100 microM. These findings suggest that PDE8B is a new member of the PDE8 family.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1998

Detection of DNA Fragmentation in Human Breast Cancer Tissue by an Antibody Specific to Single-stranded DNA.

While there have been many reports concerning the clinical significance of bcl-2 expression in human breast cancer, little is known about apoptosis in primary breast cancers. We immunohistochemically examined DNA fragmentation in 107 primary human breast cancers from Japanese women using an antibody specific to single-stranded DNA. The apoptosis index calculated as the product of the positive cell number and the cellularity coefficient, ranged from 0 to 48. The average incidence of apoptosis was calculated as 0.1% of tumor cells. No relationships were observed among the apoptosis index, expression of bcl-2, and the histological grade of the tumors. Almost all apoptotic cells were phagocytosed by surrounding tumor cells immediately after DNA fragmentation. Apoptotic body formation was rare. The apoptotic cells seemed to be degraded within phagocytes, leaving no trace of apoptosis except the tiny shells of nuclei. The intensive phagocytic reaction might be one of the main reasons for the low incidence of apoptosis in human breast cancers.

Journal Article↗
PubMed1998

Molecular cloning, expression and tissue distribution of canine lipopolysaccharide (LPS)-binding protein.

The plasma lipopolysaccharide (LPS)-binding protein (LBP) plays an important role in infection caused by Gram-negative bacteria. It is markedly increased during acute-phase responses. In this study, we cloned the full length of canine LBP cDNA and determined its amino-acid sequence and its expression in several canine tissues. The isolated LBP cDNA contained a 1443-bp coding region, which encodes a 25-amino-acid signal peptide, a 456-amino-acid mature LBP and a stop codon, and a 3'-noncoding region containing a TATTTAT motif, which is probably involved in the degradation and/or suppression of mRNA translation. The amino-acid sequence of the mature canine LBP showed 78%, 66% and 67% identity with that of human, rat and rabbit LBPs, respectively. In transient expression assays, canine and human LBPs accelerated the production of tumor necrosis factor-alpha induced by LPS in human monocytes. Northern blot analysis showed that LBP mRNA is mainly expressed in the liver and kidneys of normal dogs. In situ hybridization analysis revealed that the canine LBP mRNA is mainly located in hepatocytes and in epithelial cells of the proximal urinary tubules of the kidneys. These findings suggest that LBP is produced in organs readily exposed to LPS, where it probably plays an important role in bacterial infections, particularly in those occurring after major surgery.

Acute-Phase Proteins↗
PubMed1998

Interleukin-6 produced by pancreatic carcinoma cells enhances humoral immune responses against tumor cells: a possible event in tumor regression.

Production of interleukin-6 (IL-6) by human pancreatic carcinoma cells inversely correlates with potentials for blood-borne metastasis to the liver in nude mice. IL-6 cDNA was transfected to PCI-43, one of our cultured pancreatic carcinoma cell lines that does not produce IL-6 and generates numerous metastases to the liver. An IL-6 high-producer clone (PCI-43h) generated few metastases; IL-6 production thus has a direct effect on metastasis, whereas other transfectants (PCI-43l and PCI-43n), which are IL-6 low-, and IL-6 non-producers, respectively, did generate metastases. Tumor-reactive IgG, which mediated antibody-dependent cellular cytotoxicity (ADCC) in vitro, was detected in sera from recipient nude mice inoculated with PCI-43h but not in sera from mice given PCI-43l, PCI-43n or parent PCI-43. Tumor-reactive IgM was detected in sera from all mice, irrespective of inoculated PCI-43 species, with a slight augmentation being noted in PCI-43h-inoculated nude mice. Severe combined immunodeficiency (SCID) beige mice were then used as recipients for PCI-43 species, and tumorigeneity was examined by s.c. inoculation of a suboptimal number of PCI-43 transfectants (1 x 10(6)/0.1 ml). Only PCI-43h formed palpable masses in SCID beige mice, whereas it first grew to be palpable but subsequently became not palpable in nude mice, thereby revealing a dual action of tumor-derived IL-6. Thus, tumor-derived IL-6 confers growth promotion in SCID beige mice, while the same cytokine exhibits anti-tumorigenic functions, presumably through humoral immune responses, in nude mice.

Animals↗
PubMed1998

Effect of hepatic invasion on the choice of hepatic resection for advanced carcinoma of the gallbladder: histologic analysis of 32 surgical cases.

The purpose of this study was to assess the patterns of hepatic invasion in advanced carcinoma of the gallbladder by histologically examining surgical specimens obtained in 32 cases of hepatectomy for that carcinoma. Two modes of microscopic tumor extension were observed. The expansive pattern was restricted to liver-bed carcinomas, in which the tumor extends into the liver, primarily from the liver bed. Most of the infiltrating patterns were found with hepatic-hilar carcinomas, in which the tumor invades the hepatic hilum along Glisson's sheath, especially tumors exhibiting a discontinuous front of tumor invasion. The average width for wedge resection of the liver bed was 15.6 +/- 2.9 mm, in contrast to 25.6 +/- 8.1 mm for resection of segments IVa and V and 44.1 +/- 10.3 mm for extensive hepatic resection (both p < 0.01). When the hepatic invasion distance is more than 20 mm, the tumor should be selectively managed by extensive hepatic resection, such as extended right hepatic lobectomy or central bisegmentectomy. The results suggest that wedge resection of the liver bed and resection of segments IVa and V are advisable for carcinoma localized to the gallbladder alone and for liver-bed carcinoma with slight hepatic invasion and an expansive tumor growth pattern. Extensive hepatic resection, however, is recommended for carcinoma of the invasive liver-bed type and carcinoma of the hepatic-hilar type.

Gallbladder Neoplasms↗
PubMed1998

Phase II trial of combination chemotherapy with cisplatin, carboplatin and etoposide in stage IIIB and IV small-cell lung cancer. Fukuoka Lung Cancer Study Group.

PURPOSE: A phase II trial combining cisplatin, carboplatin and etoposide was conducted in previously untreated patients with stage IIIB and IV small-cell lung cancer, in an attempt to increase response rates and prolong survival. METHODS: Previously untreated patients with small-cell lung cancer, with measurable disease, aged < or = 72 years, performance status < or = 2, and adequate hematologic, hepatic and renal function were enrolled in the study. They were treated with 80 mg/m2 cisplatin on day 1, 100 mg/m2 carboplatin on days 2, 3 and 8, and 50 mg/m2 etoposide on days 1, 2, 3 and 8. RESULTS: A total of 46 patients (20 with stage IIIB and 26 with stage IV disease) were enrolled in the study. A total of 186 courses of chemotherapy were given, and the dose was reduced in 27 courses (15%). The chemotherapy was repeated for four or more courses in 30 patients. There were 10 complete responses and 32 partial responses, for a total response rate of 91% (95% confidence interval, 79% to 98%). The median survival time and 2-year survival rates were 18 months and 22% for stage IIIB disease, and 14 months and 15% for stage IV disease. Major side effects were hematologic: leukopenia, anemia, and thrombocytopenia of grade 3 or more occurred in 48%, 46%, and 43% of patients, respectively. CONCLUSIONS: The three-drug regimen of cisplatin, carboplatin and etoposide is feasible and active against small-cell lung cancer.

Aged↗
PubMed1998

Surgical strategies for carcinoma of the hepatic duct confluence.

BACKGROUND: This study was conducted to clarify the clinicopathological factors influencing appropriate surgical strategy and survival in patients with carcinoma of the hepatic duct confluence. METHODS: A total of 66 patients who underwent local resection of the bile duct with (n = 44) and without (n = 22) hepatectomy were reviewed retrospectively. RESULTS: Fifteen of the 44 patients who had hepatectomy and two of the 22 who did not suffered major postoperative complications (P < 0.05). As the pT category rose, the incidence of microscopic tumour extension increased significantly. Invasion at the surgical margins was more frequent in the patients who did not have hepatectomy than in those who did. Extramural tumour extension was found in 23 of 28 patients, and its prevalence was higher in the hepatic direction than the duodenal direction. Cancer invasion to the caudate lobe was found in nine of 21 patients. Thirty of 44 patients who underwent hepatectomy had a curative resection compared with six of 22 who did not have hepatectomy (P < 0.01). The cumulative survival rates after curative resection were significantly higher than after non-curative resection (P < 0.01). CONCLUSION: Hepatectomy with caudate lobectomy improves the curability and prognosis because these tumours frequently invade the surgical margins. However, operative morbidity is higher with this procedure.

Adult↗
PubMed1998

Cell death in the brain of the HTx rat.

The structural changes in the hydrocephalic brain suggest that cell death must be a significant factor in the loss of cortical mantle thickness and cell numbers. In the developing hydrocephalic brain a similar conclusion might also be reached. We present data suggesting that in the developing hydrocephalic HTx rat brain, there are at least two processes that underlie the structural deficit in the cortex. The first is abnormal development of the cortex probably resulting from a combination of the genetic defect and blockage of CSF circulation in the fetus. The second is a direct consequence of raised intracranial pressure and is manifested in a lack of development of glial cells in the neonatal brain and in the loss of myelination and neurones as pressure rises after birth, particularly after skull plate fusion. We find little evidence of increased cell death by apoptosis, recording instead a decrease in apoptotic index. There is evidence that necrosis must have occurred.

Animals↗
PubMed1998

Antibody against single-stranded DNA useful for detecting apoptotic cells recognizes hexadeoxynucleotides with various base sequences.

Our previous study demonstrated that an antibody against single-stranded DNA could detect apoptotic cells [Naruse et al. (1994) Histochemistry 101, 73-78]. In this paper we describe the development of an improved method for the production of the antibody and investigations into the antigenic determinants of the antibody so that it could be of practical use for detecting apoptotic cells. Rabbits, hyperimmunized with complexes of alkaline-denatured calf thymus DNA and methylated bovine serum albumin, produced an IgG antibody to single-stranded DNA. Analysis by sandwich ELISA using various naturally occurring nucleic acids revealed that the antibody was specific to single-stranded DNA. Furthermore, using synthetic polymers in the assay, it was found that the antibody could recognize single-stranded DNA with various base sequences. Gel electrophoresis retardation assays, with synthetic oligodeoxynucleotides with differing lengths of single-stranded DNA, indicated that a hexadeoxynucleotide constituted the minimum size of the antigenic determinants, and suggested that the antibody probably consists of several antibodies which recognize hexadeoxynucleotides with various base sequences. Western blot analysis demonstrated that the antibody can recognize both a DNA ladder and oligonucleosomes prepared from rat liver nuclei with endogenous endonuclease. The present findings demonstrate that this antibody is a useful tool for detecting apoptotic cells.

Animals↗
PubMed1998

Staging and extended resection for pancreatic cancer.

Extended surgery is being widely performed to treat pancreatic cancer in Japan, but it has not been evaluated in the same way as in other countries. We, therefore, compared the Japanese Stage Classification (JPN-SC) with the Union Internationale Contre le Cancer Stage Classification (UICC-SC) in the surgical cases of pancreatic cancer treated in our department and then assessed the results of extended resection and associated problems. Problems existed in the resection rates and actuarial survival rates in stages II and III in the UICC-SC, and the JPN-SC was found to reflect more accurately the outcome. On the other hand, although improvements in curative resection and actuarial survival rate have been achieved as a result of extended resection in Japan, the outcome in JPN-SC surgical stage IVb and highly advanced cases in which these resections proved to be noncurative even though they were classified as surgical stage IVa was extremely poor. In the future, it will be necessary to decide on a single-stage classification that is accepted throughout the world and to conduct prospective studies matched to the degree of tumor progression.

Humans↗
PubMed1998

The effects of a thromboxane A2 synthesis inhibitor and a prostaglandin I2 analogue on experimental acute necrotizing pancreatitis in rats.

To elucidate the role of thromboxane A2 (TxA2) and prostaglandin I2 (PGI2) in acute necrotizing pancreatitis (ANP) in rats and to determine the effect of the TxA2 synthesis inhibitor OKY-046 and the PGI2 analogue OP-2507, the levels of two prostanoids (TxB2, 6-keto PGF1alpha) and two types of phospholipase A2 (PLA2) activity (cytosolic and secretory) were measured in plasma and three tissues (pancreas, lung, and kidney) after injection of a mixed solution of 5% sodium taurocholate and 0.1% trypsin into the pancreatic duct to induce ANP. The survival rate 24 h after inducing ANP was 33.3% in the nontreated group, versus 83.3 and 58.3% in the groups treated with OKY-046 and OP-2507, respectively. Only the group treated with OKY-046 showed significant improvement compared with the nontreated group. The plasma, pancreatic, and pulmonary TxB2 levels decreased significantly in the group treated with OKY-046, and the histopathological changes were not as severe. The levels of pancreatic and pulmonary cytosolic PLA2 activities decreased, and plasma and pancreatic secretory PLA2 activities also decreased. In conclusion, the levels of both types of PLA2 activity and TxA2 production decreased, and the survival rate improved as a result in the group treated with OKY-046, but OP-2507 had no effect on ANP. TxA2 and two types of PLA2 activity play an important role in the process of aggravation of acute pancreatitis.

6-Ketoprostaglandin F1 alpha↗
PubMed1998

A case of inflammatory pseudotumor of the liver causing elevated serum CA19-9 levels.

Inflammatory pseudotumor of the liver is a rare lesion characterized by proliferating fibrovascular tissue admixed with inflammatory cells. A 50-yr-old Japanese man was hospitalized because of upper abdominal pain and high fever. Computed tomography revealed a poorly demarcated, low density mass in the left lobe of the liver, and abnormal laboratory findings included WBC 9340/mm3, CRP 10.5 mg/dl, and marked elevation of CA19-9 to 1167.9 U/ml. Endoscopic retrograde cholangiography showed irregularity of the intrahepatic bile duct of the left lateral segment, and the lateral segmental branches of the portal vein were not visualized on the venous phase of abdominal angiography. Ultrasound-guided liver biopsy was performed, but malignant disease, including intrahepatic cholangiocarcinoma, could not be completely ruled out. The patient underwent left hepatic lobectomy with lymph node dissection. Histopathological examination yielded a definitive diagnosis of inflammatory pseudotumor. The lesion was immunohistochemically stained for CA19-9 by the ABC method, and the biliary epithelium in severely inflamed portal canals was found to be positive. The markedly elevated preoperative level of CA 19-9 decreased to almost within the normal range and the patient remains well 2 yr 9 months after surgery, without any complications.

Angiography↗
PubMed1998

Central bisegmentectomy of the liver plus caudate lobectomy for carcinoma of the gallbladder.

Central bisegmentectomy of the liver is recommended as a radical surgical procedure for patients with liver-bed gallbladder carcinoma, which tends to directly invade the hepatic parenchyma through the liver bed. In this article, we describe the indications and our surgical techniques for central bisegmentectomy of the liver plus caudate lobectomy for carcinoma of the gallbladder. We employ combined resection of the caudate lobe, because the caudate lobe often becomes involved even in patients with liver-bed carcinoma. Resection of the extrahepatic bile duct is also required to achieve complete lymphadenectomy within the hepatoduodenal ligament, because tumor invasion of the hepatoduodenal ligament is frequently found. Extensive lymphadenectomy around the head of the pancreas together with removal of the para-aortic lymph nodes should be performed in patients with extensive lymph node metastases.

Gallbladder Neoplasms↗
PubMed1998

Involvement of apoptosis and cyclin D1 gene repression in growth inhibition of T-47D human breast cancer cells by methylglyoxal bis(cyclopentylamidinohydrazone).

Polyamines are considered to be important intracellular molecules for the proliferation of the cancer cells. In this study, effects of methylglyoxal bis(cyclopentylamidinohydrazone) (MGBCP), a potent inhibitor of the polyamine biosynthetic pathway, on the growth and cell cycle of T-47D human breast cancer cells were investigated. MGBCP dose-dependently inhibited the growth of T-47D cells, in which the contents of spermine, spermidine and putrescine decreased concomitantly. The gene expression of cyclin D1 was also repressed by the MGBCP treatment. The MGBCP-treated cells clearly exhibited morphological changes indicating the blebbing and chromatin condensation which are characteristic of apoptosis. Flow cytometric analysis showed hypo-diploid subpopulations due to apoptotic cells, and characteristic oligonucleosomal-sized DNA fragments were clearly observed for MGBCP-treated cells as the concentration of the drug was increased. These findings suggest that the inhibition of polyamine synthesis results in the repressions of cyclin D1 expression and cell cycle progression, eventually inducing apoptosis in these human breast cancer cells.

Antineoplastic Agents↗
PubMed1998

Overexpression of caltractin gene in tumor-infiltrating lymphocytes.

Differential display is a technique which relies on the polymerase chain reaction to identify messenger RNA differences between related tissue samples. We have employed an improved differential display technique, called fluorescent differential display (FDD), to identify the genes that are differentially expressed in normal and malignant mammary tissues. From FDD fingerprints, we identified changes in intensity of approximately 3% (185 bands) of a total of 5, 837 bands. Each of these 185 bands represented a differentially expressed gene, and we focused our attention on the expression of the gene for caltractin, a member of the calcium-binding EF-hand protein superfamily. Northern blot analysis revealed that the level of mRNA for caltractin was higher in breast carcinoma than in corresponding normal tissue in all cases tested (5/5). Moreover, high-level expression of the gene for caltractin was also recognized in other malignant tumors, such as hepatocellular carcinoma (HCC), gastric cancer and leiomyosarcoma. The results of in situ hybridization showed strong stainings for caltractin mRNA in tumor-infiltrating lymphocytes (TIL), but not in malignant tumor cells. Our data suggests that the caltractin gene might be associated with the function of TIL.

Adult↗
PubMed1998

Stage classifications of pancreatic cancer: comparison of the Japanese and UICC classifications and proposal for a new staging system. Union Internationale Contre le Cancer.

In the 4th edition of General Rules for the Study of Pancreatic Cancer by the Japan Pancreas Society (JPS), published in 1993 (English version published in 1996), a system resembling the TNM classification by the Union Internationale Contre le Cancer (UICC) was adopted, based on the results of precise analysis of data from 11,317 cases of carcinoma of the pancreas registered by the JPS during the 10-year period from 1981 to 1990. We compare the two TNM classifications and staging groups, focusing on the simplicity and reproducibility of the diagnostic criteria and the reliability of predicting outcome. To compare the prognostic value of the two classification systems, we analyzed the published data on resected cases registered by Pancreatic Cancer Registration Committee of the JPS. The results showed that a major drawback of the JPS classification is that is difficult to apply and has poor reproducibility. Survival rates differed significantly among the four stages in the JPS classification, whereas the UICC staging system did not reflect differences in outcome among the four stages, especially between stages II and III. The prognostic value of the UICC T category is better than that of the JPS T category, whereas the N category of JPS has better prognostic value than that of the UICC system. Believing that a combination of the two systems would solve this problem, we propose a new TNM classification and stage-grouping system that draws on the merits of both. This new system may provide improvements in staging classification that will lead to the establishment of a more practical and universal staging system for ductal carcinoma of the pancreas.

Humans↗
PubMed1998

[Endotoxin and its binding protein in organ failure].

Endotoxin (lipopolysaccharide: LPS) infection due to bacterial translocation is intimately involved in the organ failure that occurs after highly invasive interventions such as extensive liver resection, and has attracted a great deal of interest. LPS that has translocated into portal blood binds to LPS-binding protein (LBP) and is transported to the monocytes and Kupffer cells in liver sinusoids where it is activated through the soluble CD14 that is present on their cell membranes or in blood plasma. Inflammatory cytokines such as TNF-alpha and IL-6 are produced and released by monocytes and Kupffer cells that have been activated by LPS-LBP complexes, and the endothelial cell of the sinusoids is damaged by these inflammatory cytokines. The original anticoagulant function of the damaged endothelial cells is reduced, and microcirculatory insufficiency is caused by the formation of microthrombi. It is important to understand this network mechanism and to prevent invasion, and attention has recently been focused on LBP and CD14 because of this point. The increase in LPS as a result of extensive liver resection, which is highly invasive, begins 3 hours after surgery, and peaks at 6 hours. LBP, however, is awaiting the entry of LPS, principally in the periportal hepatocytes. Its production peaks at 12 hours, and this is related to the excessive production of inflammatory cytokines have been produced, expression of LBP must be suppressed within 12 hours to inhibit this excessive reaction, and that will be the task of a future study.

Acute-Phase Proteins↗