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Katsuya Hirai

Publications and source records attributed to Katsuya Hirai.

At least 19 recordsLinked to original sources
PubMed2006

Importance of thymidine phosphorylase expression at the invasive front of T3 rectal cancer as a prognostic factor.

PURPOSE: Vascular endothelial growth factor (VEGF) and thymidine phosphorylase (TP) are angiogenic factors. We evaluated the relationship between the degree of expression of binary angiogenic factors and the malignant potential of colorectal cancer. METHODS: This study was conducted in 61 patients with T3 rectal cancer who underwent surgical curative resection between 1998 and 2002. Paraffin-embedded sections of their surgical specimens were immunostained for VEGF and TP. The relationship between the expression level of binary angiogenic factors and lymph node metastasis was evaluated. RESULTS: Expression of VEGF was present only in the tumor cells of all patients, and expression was absent in the stromal cells around the invasive front of the tumor. Expression of TP was mainly present in the stromal cells around the cancer nests or around the invasive margin of the cancer. There was no relationship between expression of TP in the stromal cells around the invasive front of the tumor and lymph node metastasis. However, there was a significant relationship between expression of TP at the invasive front of the tumor and lymph node metastasis (p = 0.014). Moreover, TP expression in the tumor cells was the only independent factor that correlated with the postoperative recurrence (p = 0.024) with an odds ratio of 11.973 by multivariate logistic regression analysis. CONCLUSION: Expression of TP at the invasive front of the tumor may be a useful indicator of the malignant potential of advanced rectal cancer.

Aged↗
PubMed2005

New approach for laparoscopic surgery of the right colon.

BACKGROUND: In patients in whom the ventral aspect of the root of the mesentery was obscured by the adherent greater omentum, laparoscopic surgery is usually abandoned. To forcefully loosen the adhesions by a laparoscopic maneuver may cause inadvertent intestinal injury. We describe a procedure, named the 'retromesen teric approach', which enables a safe laparoscopic right-sided colic operation in such circumstances. PATIENTS AND METHODS: From 2000 to 2003 in our institute, a laparoscopic right-sided colic operation was performed in 21 patients in whom the ventral aspect of the root of the mesentery was obscured by the adherent greater omentum using the retromesenteric approach (RMA; n = 16) and a conventional approach (CA; n = 5). We reviewed the medical records for the operative duration, intraoperative blood loss, conversion rates and postoperative complications. RESULTS: The duration of operation in the RMA group ranged from 75 to 120 (median 95) min, which was shorter than that in the CA group (p < 0.05). Perioperative bleeding in the RMA group ranged from 0 to 115 (median 30) ml, which was smaller than that in the CA group (p < 0.05). No conversion and no postoperative complications were noted in the both groups. CONCLUSIONS: Our new technique, in which the right colon and the ileum are dissected and lifted en bloc from the retroperitoneum, is safe and useful for laparoscopic right-sided colic operation.

Colon↗
PubMed2005

Identification and characterization of an immunodominant 28-kilodalton Coxiella burnetii outer membrane protein specific to isolates associated with acute disease.

Coxiella burnetii causes acute Q fever in humans and occasional chronic infections that typically manifest as endocarditis or hepatitis. Isolates associated with acute disease were found to be distinct from a group of chronic disease isolates by a variety of biochemical parameters and in a guinea pig fever model of acute disease, suggesting a difference in virulence potential. We compared antigenic polypeptides among C. burnetii isolates and found an immunodominant 28-kDa protein in acute group isolates but not in chronic group isolates (T. Ho, A. Hotta, G. Q. Zhang, S. V. Nguyen, M. Ogawa, T. Yamaguchi, H. Fukushi, and K. Hirai, Microbiol. Immunol. 42:81-85, 1998). In order to clone the adaA gene, the N-terminal amino acid sequence of adaA was determined and a 59-bp fragment was amplified from Nine Mile phase I DNA by PCR. The putative gene fragment was used to screen a lambda ZAP II genomic DNA library, and an open reading frame expressing a 28-kDa immunoreactive protein was identified. Sequence analysis predicted a gene encoding an approximately 28-kDa mature protein with a typical signal sequence. The adaA (acute disease antigen A) gene was detected in acute group C. burnetii isolates but not identified in chronic group isolates by PCR and Southern blotting. A typical signal peptide was predicted in adaA, and specific antibody to adaA reacted with the purified membrane fraction of acute group isolates by Western blotting, suggesting that adaA is exposed on the outer surface of C. burnetii. adaA was overexpressed in pET23a as a fusion protein in Escherichia coli to develop anti-recombinant adaA (anti-radaA) specific antibody, which recognized a approximately 28-kDa band in acute group isolates but not in chronic group isolates. In addition, immunoblotting indicates that radaA reacted with sera derived from animals infected with acute group isolates but did not react with sera from animals infected with chronic group isolates. These results support the idea that an adaA gene-targeted PCR assay and an radaA antigen-based serodiagnostic test may be useful for differential diagnosis of acute and chronic Q fever.

Acute Disease↗
PubMed2005

Usefulness of automatic triangular anastomosis for esophageal cancer surgery using a linear stapler (TA-30).

In a clinical evaluation, thirty-one patients with thoracic esophageal cancer who were treated from 1997 to 2000 were selected as subjects including those who underwent hand sewn anastomosis method, circular stapler method and triangular anastomosis method. Incidence of anastomosis failure was 27.3%, 25.0% and 8.3% for the hand sewn anastomosis method, circular stapler method and triangular anastomosis method, respectively. Anastomosis stenosis was found in 32.4%, 45.6% and 8.3% for the hand sewn anastomosis method, circular stapler method and triangular anastomosis method, respectively. In the basic examination, reduction rate of anastomosis caliber was 22.1+/-4.8%, 14.9+/-1.4% and 7.37+/-0.9%, for the hand sewn anastomosis method, circular stapler method and triangular anastomosis method. Microscopic evaluation revealed serious problems with the circular stapler method. The cause of anastomotic stenosis may include the fact that if anastomosis is performed by a circular stapler method, all the layers of gastrointestinal tract are punched out at the anastomosis portion, and mucosal conjugation is not observed and the muscular layer is exposed in the inner lumen of the gastrointestinal tract. Taking that the ulcer is formed circularly at the anastomotic portion into account, it is easily understood that this circular ulcer develops into stenosis in the healing process. The advantage of triangular anastomosis for esophago-gastric anastomosis is less suture failure, and is extremely advantageous for prevention of stenosis at the anastomotic portion when compared with other anastomosis methods. However, with regard to the healing process of eversion anastomosis in gastrointestinal tract instrumental anastomosis, detailed examination is expected hereafter.

Anastomosis, Surgical↗
PubMed2004

Proventricular adenocarcinoma in a Humboldt penguin (Spheniscus humboldti) and a great horned owl (Bubo virginianus); identification of origin by mucin histochemistry.

Cases of proventricular neoplasm in a Humboldt penguin (Spheniscus humboldti) and a great horned owl (Bubo virginianus) were observed. Microscopically, the neoplastic cells formed branching tubules or acini in both cases. Galactose oxidase-Schiff (GOS) staining revealed that the cytoplasm of the normal surface epithelium and surface mucosubstances of the proventriculus adjacent to the neoplasm were positive in both cases. The neoplastic cells in both cases were also classified as GOS-positive. Therefore, the two proventricular neoplasms in this report were diagnosed as proventricular adenocarcinoma that arose from the proventricular surface epithelium. This study suggests that the mucosubstances, which the neoplastic cells produced, were a useful index for identifying the origin of the neoplastic cells in the birds.

Adenocarcinoma↗
PubMed2004

In vitro susceptibility to tetracycline and fluoroquinolones of Japanese isolates of Coxiella burnetii.

Coxiella burnetii is the agent of the worldwide zoonosis, Q fever. The in vitro susceptibility to tetracycline and fluoroquinolones of Japanese isolates of C. burnetii was evaluated for the first time. The MICs against Japanese isolates were almost the same as the MICs against the foreign reference isolates. The results suggest that the common antibiotics therapy for Q fever used in other countries is also effective for Japanese Q fever patients.

Anti-Bacterial Agents↗
PubMed2004

Comparison of Japanese isolates of Coxiella burnetii by PCR-RFLP and sequence analysis.

The genetic variation of Japanese isolates of Coxiella burnetii, the agent of Q fever, was found for the first time. Forty-nine out of 72 isolates had the chronic pattern of the isocitrate hydrogenase gene. Sequence analysis revealed that the isolates have a specific nucleotide sequence. The putative amino acid sequence was the same as that of chronic reference strains. These results suggest the variation of C. burnetii isolates in Japan.

Amino Acid Sequence↗
PubMed2004

Use of monoclonal antibodies for analyses of Coxiella burnetii major antigens.

Monoclonal antibodies (MAbs) to major antigens of Coxiella burnetii were produced. Some of the MAbs to a 62-kDa protein antigen, peptidoglycan protein complex and lipopolysaccharide (LPS) O-chains reacted with other bacteria whereas none of the MAbs to outer membrane proteins and LPS outer-core did. The LPS outer-core and OMPs may be useful antigens for specifically detecting antibodies to C. burnetii.

Antibodies, Bacterial↗
PubMed2004

Leucocytozoon lovati infections in wild rock ptarmigan (Lagopus mutus) in Japan.

Leucocytozoon lovati infections were detected in free-flying rock ptarmigan (Lagopus mutus), an endangered species that inhabits alpine areas in Japan. Eight of nine adult birds tested positive for L. lovati infection. For comparison, two captive rock ptarmigans hatched in a breeding facility at the foot of the mountains were examined. Both were negative for L. lovati infection. This is the first report of L. lovati infection in the rock ptarmigan in Japan.

Animals↗
PubMed2004

[Home chemotherapy by concomitant UFT + Leucovorin (po.) in postoperative colorectal cancer patients assessed with Dukes D and curability C colorectal cancer].

UNLABELLED: Concomitant treatment with 5-fluorouracil (5-FU) and Leucovorin (LV) is positioned as the standard chemotherapy against colorectal cancer. We noted the action of LV to enhance the effect of biochemical modulation by 5-FU, and made an attempt at home chemotherapy with UFT + LV by oral administration, in consideration to the convenience of patients. SUBJECTS: The subjects of this study were 24 post-operative patients who had been assessed with Dukes D and curability C colorectal cancer with measurable metastatic lesions and who could tolerate chemotherapy. METHODS: 1 course of treatment consisted of 2 weeks of UFT at 300-400 mg/m2/day and LV at 15 mg/body/day followed by 2 weeks of drug withdrawal. The administration was conducted for 4 courses or more as the target. Unless serious adverse reaction occurred, dose increase of UFT was allowed. RESULTS: The efficacy rate in the 22 patients who were assessable was 22.7%. There were 11 NC patients, accounting for half (50%) of the subjects. This home chemotherapy is expected to become an alternative chemotherapy against colorectal cancer in the future, because the treatment does not require hospitalization and has less impact on the QOL of patients.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2003

Epidemiological survey on the route of Coxiella burnetii infection in an animal hospital.

The source of Q fever infection, was investigated by serological and polymerase chain reaction (PCR) analysis of specimens from humans and pets in an animal hospital. Two animal health technicians showed a positive serological reaction against Coxiella burnetiiat the start. One of the two positive subjects remained PCR-positive for about 1 year and the other converted to PCR-negative, but the IgG antibody titer remained at 1 : 128 after minocycline treatment. Among animals housed in the hospital, two dogs were PCR-positive at the start, and the infection was transmitted to three cats about 5 months later. All these animals became negative for C. burnetii DNA after minocycline treatment. Furthermore, C. burnetii was isolated from the sera of the two humans and two dogs. C. burnetiiisolates from the humans and dogs were analyzed, and it was found that the sequence homology of the com1 region was high, 99.9%, and the QpH1 plasmid was detected. These results suggest that these isolates were the same type, and it was considered that the infection was derived from the dogs, though the time of infection could not be confirmed.

Animals↗
PubMed2003

Diagnostic evaluation of 2', 5'-oligoadenylate synthetase activities and antibodies against Epstein-Barr virus and Coxiella burnetii in patients with chronic fatigue syndrome in Japan.

To investigate the association of viral infections with chronic fatigue syndrome (CFS), we assayed 2', 5'-oligoadenylate synthetase (2-5AS) activities in peripheral blood mononuclear cells from CFS patients in Japan. These patients were diagnosed in two hospitals, H1 and H2, located in different areas of the country. The activities were detected in 19 (86%) and 7 (32%) of each of the 22 patients in H1 and H2, respectively, while they were detected in only four (11%) out of the 38 healthy controls. IFN-alpha was similarly detected in a few CFS patients and healthy controls. We also assayed the antibody titers against Epstein-Barr virus (EBV) and Coxiella burnetii in these patients. The EBV anti-EA-IgG antibodies were detected in two (9%) and seven (32%) of each of the 22 patients in H1 and H2, respectively. Anti-C. burnetii IgG antibodies were detected in six (27%) out of 22 patients in H1 but not in 22 patients in H2, while they were detected in one (11%) of the nine healthy controls. Some CFS patients may be associated with EBV or C. burnetii infection. There were some statistical correlations between the 2-5AS activities and antibody titers of EA-IgG (P < 0.05, Student's t-test) but not to the antibody titers of C. burnetii. The up-regulation of 2-5AS activities suggests immunological dysfunctions with some virus infections in the CFS patients. Our results indicate that 2-5AS activities are useful for a diagnostic marker of CFS and for exploring the complicated pathogenesis of CFS.

2',5'-Oligoadenylate Synthetase↗
PubMed2003

SCID mouse model for lethal Q fever.

Q fever, a worldwide zoonosis caused by Coxiella burnetii, has many manifestations in humans. Endocarditis is the most serious complication of Q fever. Animal models are limited to acute pulmonary or hepatic disease and reproductive disorders. An appropriate experimental animal model for Q fever endocarditis does not yet exist. In this study, severe combined immunodeficient (SCID) mice infected with C. burnetii showed persistent clinical symptoms and died, whereas immunocompetent mice similarly infected became asymptomatic and survived. The SCID mice examined in this study had severe chronic lesions in their primary organs: the heart, lung, spleen, liver, and kidney. The heart lesions of the SCID mice were similar to those in humans with chronic Q fever endocarditis: they had focal calcification and expanded macrophages containing C. burnetii. The 50% lethal dose of C. burnetii in SCID mice was at least 10(8) times less than that in immunocompetent mice. The SCID mouse is highly susceptible to C. burnetii, and the immunodeficiency of the host enhances the severity of Q fever. This animal model could provide a new tool for the study of chronic Q fever and Q fever in immunodeficient hosts.

Animals↗
PubMed2003

Seroprevalence of Coxiella burnetii infections among cats in different living environments.

The seroprevalence of Coxiella burnetii infection among pet cats in Japan and Korea and stray cats in Japan was investigated by an indirect fluorescent antibody technique and PCR test. Forty-four (14.2%) of 310 pet cats in Japan were seropositive, as were 15 (41.7%) of 36 stray cats in Japan and 10 (8.6%) of 116 pet cats in Korea. The antibody positive rate in stray cats was significantly higher than that in pet cats, but there was no correlation between the rates in Japanese and Korean pet cats. In this study, the prevalence of C. burnetii infection among cats in different living environments was found and it is difficult to deny that stray cats would be one of the important sources of infection for human Q fever.

Animals↗
PubMed2002

Phase variation analysis of Coxiella burnetii during serial passage in cell culture by use of monoclonal antibodies.

Antigenic changes in Coxiella burnetii Nine Mile strain phase I during serial passages in cell culture were analyzed with three groups of monoclonal antibodies (MAbs) against lipopolysaccharide. The MAbs of group 1 did not react with organisms that were passaged over five times, and the MAbs of group 2 did not react with organisms that were passaged over eight times. The MAbs of group 3 reacted with organisms passaged up to 15 times but did not react with phase II cells. These results suggest that C. burnetii could be differentiated into four phase states during phase variation.

Animals↗