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Biomedical subjects

M Hirota

Publications and source records attributed to M Hirota.

At least 37 records · Page 2Linked to original sources
PubMed2001

Percutaneous embolization of the distal pancreatic duct to treat intractable pancreatic juice fistula.

Pseudocysts and post-necrotic collections of the pancreas are sometimes treated by percutaneous drainage. In cases of post-necrotic collection, intractable pancreatic juice fistula is often formed by disruption of the main pancreatic duct in the necrotized region. We radically treated intractable pancreatic juice fistulae by selective cannulation into the distal pancreatic duct via the route for percutaneous drainage of post-necrotic collections to extinguish the exocrine function of the caudal pancreas. We performed this procedure in two patients in whom the major pancreatic duct was damaged at the body of the pancreas, which was extensively necrotic. Although mild symptoms of acute pancreatitis appeared in both patients after the first procedure, they recovered without severe side effects. Neither recurrence of pancreatic juice fistulae nor reduction of the glucose tolerance was caused by removing the exocrine function of the caudal pancreas in either patient 32 and 24 months after treatment, respectively. This method is an effective treatment modality with which to treat intractable pancreatic juice fistulae with damage of the main pancreatic duct.

Adult↗
PubMed2001

Tumor necrosis factor-related apoptosis-inducing ligand and its receptor expression and the pathway of apoptosis in human pancreatic cancer.

METHODOLOGY: The authors performed the reverse transcription-polymerase chain reaction (RT-PCR) in 17 cases of pancreatic ductal cell carcinoma (PDC) and five cases of normal pancreatic tissues to determine the expression of tumor necrosis factor -related apoptosis-inducing factor (TRAIL) and its five receptors in PDC. RESULTS: The expression of TRAIL and its receptors other than osteoprotegerin was found frequently in both PDC and normal tissues. whereas the expression of osteoprotegerin was detected only in PDC. The authors detected cancer cell death by TRAIL, ranging from 37% to 77% in all the PDC cell lines by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Hochest staining revealed that cell death was caused by apoptosis. Caspase-8 and caspase-3 and poly (ADP-ribose) polymerase cleavage was activated within 2 hours after stimulation with 200 ng/mL TRAIL. CONCLUSION: These findings suggest a relation between osteoprotegerin expression and the biologic aggressiveness of PDC and the involvement of caspase-8 and caspase-3 activation in the TRAIL-mediated apoptosis pathway in PDC.

Apoptosis↗
PubMed2001

DNA inversion in the tail fiber gene alters the host range specificity of carotovoricin Er, a phage-tail-like bacteriocin of phytopathogenic Erwinia carotovora subsp. carotovora Er.

Carotovoricin Er is a phage-tail-like bacteriocin produced by Erwinia carotovora subsp. carotovora strain Er, a causative agent for soft rot disease in plants. Here we studied binding and killing spectra of carotovoricin Er preparations for various strains of the bacterium (strains 645Ar, EC-2, N786, and P7) and found that the preparations contain two types of carotovoricin Er with different host specificities; carotovoricin Era possessing a tail fiber protein of 68 kDa killed strains 645Ar and EC-2, while carotovoricin Erb with a tail fiber protein of 76 kDa killed strains N786 and P7. The tail fiber proteins of 68 and 76 kDa had identical N-terminal amino acid sequences for at least 11 residues. A search of the carotovoricin Er region in the chromosome of strain Er indicated the occurrence of a DNA inversion system for the tail fiber protein consisting of (i) two 26-bp inverted repeats inside and downstream of the tail fiber gene that flank a 790-bp fragment and (ii) a putative DNA invertase gene with a 90-bp recombinational enhancer sequence. In fact, when a 1,400-bp region containing the 790-bp fragment was amplified by a PCR using the chromosomal DNA of strain Er as the template, both the forward and the reverse nucleotide sequences of the 790-bp fragment were detected. DNA inversion of the 790-bp fragment also occurred in Escherichia coli DH5alpha when two compatible plasmids carrying either the 790-bp fragment or the invertase gene were cotransformed into the bacterium. Furthermore, hybrid carotovoricin CGE possessing the tail fiber protein of 68 or 76 kDa exhibited a host range specificity corresponding to that of carotovoricin Era or Erb, respectively. Thus, a DNA inversion altered the C-terminal part of the tail fiber protein of carotovoricin Er, altering the host range specificity of the bacteriocin.

Bacteriocins↗
PubMed2001

Molecular and epidemiological study of the first outbreak of vanB type vancomycin-resistant Enterococcus faecalis in Japan.

In July, 1999, an outbreak of vancomycin-resistant Enterococcus faecalis (VREF) with the vanB genotype occurred for the first time in Japan at Hokushin General Hospital, Nakano City, Nagano Prefecture. Four VREF strains were isolated from the clinical specimens of four inpatients, and 16 VREF strains were isolated by the screening of asymptomatic carriers and by surveillance of the hospital environment. All of the isolates possessed vanB genes. In a pulsed-field gel electrophoresis analysis, 19 out of 20 VREF isolates exhibited the indistinguishable restriction endonuclease digestion patterns of the chromosomal DNA. Additional investigation by Southern hybridization using the vanB probe implied that the vanB gene of these 19 isolates was encoded on a 110-kb plasmid. These findings indicate that the outbreak was principally caused by a single clone. The restriction endonuclease digestion patterns of the remaining single isolate was different from those of the other isolates. The vanB gene was encoded on the chromosome.

Aged↗
PubMed2001

[Efficacy of local ablation therapy for liver metastasis from colorectal cancer--radiofrequency ablation and microwave coagulation therapy].

We evaluated the efficacy of local ablation therapy in 40 patients with liver metastases from colorectal cancer. Radiofrequency ablation (RFA) and/or microwave coagulation therapy (MCT) were used. Ablation therapies were performed in percutaneous, endoscopic, and operative procedures. The regional recurrence rate at the therapeutic sites was 15% (median follow-up period of 2.5 years). The average surgical margin in the operative ablation group was 11 mm. The cumulative 5-year survival rates were 37% in the local ablation, 41% in the hepatic resection, and 5% in the regional chemotherapy groups. Major complications occurred in only two patients (one biliary fistula and one liver abscess). Together these observations indicate that local ablation therapy is a radical and safe locoregional therapy that provides adequate local control and contributes to long survival.

Catheter Ablation↗
PubMed2001

[Lymph node excision with laparotomy and chemo-radiation therapy for a hepatocellular carcinoma patient with multiple lymph node metastases].

We reported a case of hepatocellular carcinoma (HCC) with multiple lymph node metastases. The patient was a 67-year-old male with C type liver cirrhosis. He underwent microwave coagulation therapy (MCT) for HCC (5 cm and 1.5 cm) 1.5 years before admission. Abdominal CT scan revealed a well-enhanced tumor (2 cm) in caudate lobe of the liver and excessive lymph node metastases, locating in the inferior phrenic, periportal and para-aortic area. The preoperative serum AFP and AFP-L3 levels were 41.9 ng/ml and 93.1%, respectively. At laparotomy, systematic dissection of the enlarged lymph nodes and MCT of the hepatic tumor was performed. After operation, residual inferior phrenic lymph node was treated with irradiation therapy (total 50.4 Gy). The lymph node showed complete response (CR) for about a year and the AFP-L3 level returned to the normal range. After 9 months, a supra-clavicular lymph node was detected on abdominal CT scan. Irradiation therapy (total 45 Gy) in combination with CDDP (100 mg) and 5-FU (4,000 mg) was applied. The lymph node had been assessed as partial response for 6 months. The patient lived quite well after these therapies, but died of hepatic failure 32 months after the initial operation. In conclusion, we recommend this therapeutic strategy using operative excision and chemo-radiation therapy for HCC with multiple lymph node metastases.

Aged↗
PubMed2001

[A case report of advanced hepatocellular carcinoma successfully treated with surgical multi-ablation therapy based on radio-frequency thermal ablation].

We report a patient with advanced hepatocellular carcinoma (HCC) who was successfully treated with multi-ablation therapy by the surgical method of laparotomy and partial thoracotomy. A 67-year-old man, who had undergone transcatheter arterial embolization (TAE) three times for advanced HCC with hepatitis C, presented at our hospital in May 2001. Although TAE had been performed 3 times starting 2 years earlier, interventional therapy for recurrent tumors is difficult because of stenosis and obstruction of regional hepatic arteries. Computed tomography of the liver revealed five tumors in both lobes and the tumor in segment VIII presented difficulty for percutaneous ablation treatment due to its closeness to the trunk of the hepatic vein. Multi-ablation therapy consisting of radio-frequency ablation, microwave ablation and ethanol injection was selected for this patient. By laparotomy and partial thoracotomy, we performed multi-ablation therapy safely and accurately for each tumor. After this treatment, 5 tumors in both lobes showed no viability on dynamic CT and the patency of the right hepatic vein was preserved. Six months after the treatment, one remnant mass appeared in segment V. An additional two sessions of percutaneous RFA were performed for this tumor. At the end of these treatments, enhanced CT revealed no viability of the tumors, and serum alpha-fetoprotein and PIVKA-II level dropped to the normal range. This case suggests that multiple ablation therapy with a surgical method is feasible and useful in cases of advanced hepatocellular carcinoma.

Aged↗
PubMed2001

[Complete response (CR) in a case of advanced hepatocellular carcinoma by percutaneous multi-ablation therapy].

A 56-year-old male patient was diagnosed with hepatocellular carcinoma by abdominal ultrasonography. The tumor was located in segment 7-1 and was 7 cm in diameter. Two transcatheter arterial chemoembolizations (TACE) were not effective. The patient had experienced more than ten fractures because of fibrous dysplasia of the bone. Laparotomy was very risky, so we decided to perform multi-ablation therapy. This therapy consists of percutaneous radiofrequency ablation (RFA) and percutaneous ethanol injection therapy (PEIT). PEIT was applied to the lesion where extrahepatic the Glisson's capsule was near the tumor. After two sessions with these therapies, the tumor with the surrounding liver parenchyma turned necrotic. A complete response was obtained and the patient has been disease-free for 6 months. We conclude that our multi-ablation therapy is effective for patients with advanced hepatocellular carcinoma who have therapeutic limitations because of some preoperative complications.

Carcinoma, Hepatocellular↗
PubMed2001

[Pulmonary surgery for pulmonary lesion with pulmonary tuberculosis or of tuberculosis].

Nine patients with pulmonary tuberculosis underwent open chest surgery for pulmonary lesions of tuberculosis or other than tubercolosis. They were 1 case of lung cancer, 4 cases of pneumothorax, 1 case of multi drug resistant pulmonary tuberculosis and 3 cases of tuberculoma. Postoperative complications developed in 3 cases including 2 of pneumothorax and 1 of lung collapse.

Adolescent↗
PubMed2001

Fluoroquinolone concentrations in plasma, urine, and bile after oral administration in rats with renal failure: useful technique for long-term bile collection.

Using a previously reported technique for bile collection, we studied the pharmacokinetics of levofloxacin (LVFX) and grepafloxacin (GPFX) in normal rats and in animals with renal failure. Continuous bile drainage was performed using normal and renal-failure Wistar rats. Oral GPFX or LVFX (40 mg/Kg) was administered. The drug concentrations in plasma, urine, and bile were determined by high-performance liquid chromatography. The area under the blood concentration-time curve (AUC) in each renal-failure rat was calculated. There were no significant differences in GPFX concentrations in the serum, urine, and bile between the renal-failure and normal rats, but the LVFX level in the urine of the renal-failure group was statistically significantly lower than in the normal group. The AUC of GPFX had an opposite correlation with the degree of renal failure, but that of LVFX was correlated.

Administration, Oral↗
PubMed2000

Novel anti-inflammatory compounds from Myrsine seguinii, terpeno-benzoic acids, are inhibitors of mammalian DNA polymerases.

Novel anti-inflammatory compounds, terpeno-benzoic acids, were found from the plant, Myrsine seguinii. The strongest of these anti-inflammatory agents, 3-geranyl-4-hydroxy-5-(3'-methyl-2'-butenyl) benzoic acid (compound 1), showed an inhibitory effect against enzymes involved in replication, such as calf DNA polymerase alpha (pol. alpha), rat DNA polymerase beta (pol. beta) and one of the beta family polymerases, calf thymus terminal deoxynucleotidyl transferase (TdT). The minimum inhibitory concentration (MIC) and IC50 values were 82 and 22 microM for pol. alpha, 86 and 11 microM for pol. beta, 140 and 46 microM for TdT, respectively. However, compound 1 did not influence the activities of plant DNA polymerases, human immunodeficiency virus type-1 reverse transcriptase, any of the prokaryotic DNA polymerases or DNA and RNA metabolic enzymes tested. Dose-dependent relationships were observed between the anti-inflammatory activities and the DNA polymerase-inhibitory activities of the four derivatives. The carboxylic acid moiety in the benzoic acid of the compounds appeared to be related to the inhibitory effects. The mode of action of the terpeno-benzoic acids against the polymerases and their relationships to the anti-inflammatory activity are discussed.

Animals↗
PubMed2000

Cleavage of hepatitis C virus nonstructural protein 5A by a caspase-like protease(s) in mammalian cells.

Nonstructural 5A protein (NS5A) of hepatitis C virus (HCV) is localized in the cytoplasm although it has a functional nuclear localization signal. To clarify the determinant of NS5A cytoplasmic localization, various N- or C-terminal deleted NS5A mutants were generated and their subcellular localization was analyzed in cell lines after transient expression. N-terminal deleted forms of NS5A were localized in the nucleus, and the sequence of the N-terminal 27 amino acids of NS5A had sufficient function to cause retention of a normally nuclear protein in the cytoplasm. These observations indicated that cytoplasmic localization of NS5A is determined primarily by the N-terminal region of the molecule. In addition, we found proteolytic processing of NS5A in transiently expressing cells. In these cells, cleavage occurred at a few sites located in the N- and C-terminal regions of NS5A. This cleavage in cells was enhanced by apoptotic stimuli and was inhibited by the caspase inhibitor Z-VAD-FMK, suggesting that a caspase-like protease(s) contributes to the cleavages of NS5A. Based on the results of mutational analysis of NS5A, we predicted one cleaved form, which had lost both the N- and the C-terminal portions of NS5A, to be composed of amino acid residues 155 to 389. Peptide containing the same amino acid sequence as this cleaved product was localized in the nucleus. Furthermore, we found that a fusion protein consisting of Gal4 DNA-binding domain fused with this cleaved form showed transcriptional activity only when the alpha-catalytic subunit of protein kinase A (PKA) was coproduced, suggesting that the transcriptional activity of this product was regulated by PKA. These results suggested that the cleavage product of NS5A by a caspase-like protease(s) plays a role in transcriptional regulation of the host cell gene(s) in HCV-infected cells.

Amino Acid Sequence↗
PubMed2000

HTLV-1 tax oncoprotein represses the p53-mediated trans-activation function through coactivator CBP sequestration.

The human T-cell leukemia virus type 1 (HTLV-1) Tax oncoprotein repressed the transcriptional activity of wild-type p53 through its N-terminal trans-activation domain. Although Tax did not directly bind to p53, this repression required the activation of CREB pathway by Tax. In contrast to a recent report by Pise-Masison et al. (1998a, b) we found that the phosphorylation of p53 on Ser 15 is not a major cause of the Tax-mediated inactivation of p53. However, Tax with a mutation in the coactivator CBP-binding site (K88A), which activates NF-kappaB but not the CREB pathway, could not repress the p53 trans-activation function. Moreover, Tax inhibited p53 binding to CBP in vitro and inhibited synergistic activation of transcription by CBP and p53. Thus, Tax is likely to compete with p53 in binding with CBP, thereby repressing its trans-activation function.

Binding, Competitive↗
PubMed2000

Treatment of childhood renal cell carcinoma with lymph node metastasis: two cases and a review of literature.

Standard treatment for renal cell carcinoma (RCC) is radical nephrectomy with lymph node dissection. Stages I and II have encouraging prognoses, but Stage III with regional lymph node metastasis can be unfavorable. Adjuvant therapy for pediatric patients with advanced RCC with lymph node involvement or metastatic lesion has not been defined. Advanced pediatric RCC is reported in two patients (boys, aged 6 and 9 years: Stage IIIs, Robson; Stage III and IV, pTNM classification) treated by nephrectomy and lymph node dissection followed by postoperative interferon-alpha (IFN), that can be used as an adjuvant therapy with side effects such as fever, bone marrow suppression, or decreased liver function. One is doing well for 7 years, another is suffered from lung metastases at 3 years after surgery. Although immunotherapy is expected to improve survival in pediatric patients with advanced RCC, surgical resection of renal and metastatic tumors remains the standard treatment.

Antineoplastic Agents↗
PubMed2000

Increased concentrations of plasma IL-18 in patients with hepatic dysfunction after hepatectomy.

We investigated the dynamic aspects of circulatory IL-18 and other inflammatory cytokines in patients who underwent a hepatectomy. In patients with post-operative hepatic dysfunction, plasma concentrations of these cytokines increased, reflecting severe surgical trauma. IL-6, IL-10 and IFN-gamma increased in the early phase, while IL-18 increased in the later phase after 1 week. Interestingly, the increase in the plasma IL-18 concentration was correlated with that in serum bilirubin levels in hepatectomized patients. Hence, the decrease in the hepatic metabolism of IL-18 may cause the plasma accumulation of IL-18. This mechanism was confirmed using rat experiments. Intravenously administered human IL-18 was excreted into bile. Furthermore, the plasma clearance of human IL-18 was prolonged in bile duct-ligated rats. These results suggest that IL-18 is metabolized in the liver and excreted into bile, and an increase in plasma IL-18 in patients with hepatic dysfunction reflects the decreased metabolism in the liver.

Adult↗
PubMed2000

Elastase activity enhances the adhesion of neutrophil and cancer cells to vascular endothelial cells.

BACKGROUND: Elastase activity in cancer cells has been reported to promote their metastasis. Hence, we analyzed the influence of elastase activity of cancer cells on their responsive adhesion to vascular endothelial cells. MATERIALS AND METHODS: Human pancreatic (S2-007, S2-013, S2-020, S2-028) and colonic (COLO205) cancer cell lines were used. S2-007, S2-013, and S2-020 possess high elastase activity, whereas S2-028 and COLO205 have low elastase activity. Adhesive reactions of these cancer cells and neutrophils to TNFalpha-activated HUVEC were analyzed. Bound cells onto HUVEC were counted after incubation for 10 min. The effects of suppression of elastase activity by ZD8321, a potent elastase inhibitor, and supplementation of human neutrophil elastase (NE) on the adhesive reactions were also analyzed. In addition, E-selectin expression on HUVEC and concentrations of soluble E-selectin in the medium were measured. RESULTS: Adhesion of cells with high intracellular elastase activity to TNFalpha-activated HUVEC was suppressed by ZD8321. On the other hand, adhesion of cells with low elastase activity was enhanced by exogenous NE. Expression of E-selectin, a key molecule in leukocyte-endothelial cell interaction, on HUVEC was increased by NE. Soluble E-selectin concentration in the medium increased after the adhesive reaction between neutrophils and HUVEC. This increase was thought to be due to the shedding of cell surface E-selectin. Such responses were inhibited by ZD8321. CONCLUSION: Elastase activity has a biological function of stimulating both the E-selectin expression on HUVEC and the resultant adhesive reaction of cancer cells with them. Inhibition of elastase activity is a potent strategy for controlling cancer metastasis.

Cell Adhesion↗