Biomedical subjects

K Yanagitani

Publications and source records attributed to K Yanagitani.

6 recordsLinked to original sources

PubMed1999

Increased neutrophil chemotaxis in obstructive jaundice: an in vitro experiment in rats.

BACKGROUND AND AIMS: Changes in neutrophil functions in obstructive jaundice have been poorly understood. An in vitro experimental study was performed to evaluate the effect of obstructive jaundice on the functions of macrophages (secretion of neutrophil chemoattractants) and neutrophils (chemotaxis and superoxide anion generation). METHODS: Obstructive jaundice was produced in rats by 7 day bile duct ligation. Peripheral neutrophils and peritoneal macrophages were harvested from either normal, sham-ligated or bile duct-ligated rats and supernatants of the monolayers of the respective macrophages were prepared after stimulation with lipopolysaccharide. Neutrophil chemotaxis was evaluated with a modified Boyden method. RESULTS: The supernatant of the bile duct-ligated rat macrophages showed a chemotactic effect on normal rat neutrophils with insignificant difference from the supernatant of the sham-ligated rat macrophages. Chemotaxis of the bile duct-ligated rat neutrophils towards the supernatant of the normal rat macrophages was significantly increased, compared with that of sham-ligated rat neutrophils. Similarly, neutrophils from bile duct-ligated rats showed significantly greater chemotaxis to formyl-methionyl-leucyl-phenylalanine than the sham-ligated rat neutrophils. Superoxide anion generation in response to formyl-methionyl-leucyl-phenylalanine or phorbol myristate acetate was significantly increased in the bile duct-ligated rats compared with the sham-ligated rats. CONCLUSIONS: The results suggest that the neutrophil is primed in terms of chemotaxis and superoxide anion generation in obstructive jaundice. How these activated neutrophils play a role in the inflammatory response to obstructive jaundice should be evaluated.

Animals↗

PubMed1998

Influence of biliary obstruction on neutrophil chemotaxis.

The effect of obstructive jaundice on neutrophil chemotactic function was investigated, with a potent chemotactic factor, IL-8 (recombinant rat GRO-beta), in rats that received 7-day bile duct ligation. Carrageenin or IL-8 was injected into a preformed air pouch, and exudate was collected 4 h later for measurement of myeloperoxidase activity. In vitro chemotaxis of peripheral neutrophils to IL-8 was evaluated by a modified Boyden chamber method. Both carrageenin and IL-8 induced significantly pronounced intra-air pouch neutrophil recruitment in the bile duct-ligated group compared with a sham-ligated group. In vitro neutrophil chemotaxis was significantly increased in the bile duct-ligated group compared with the sham-ligated group. The present experimental model suggests enhanced neutrophil chemotaxis to IL-8 in obstructive jaundice.

Animals↗

PubMed1998

Effect of obstructive jaundice on neutrophil chemotactic activity: an in vivo assessment in zymosan-induced peritonitis model in rats.

The effect of obstructive jaundice on local neutrophil accumulation in response to inflammatory stimulus was investigated in rats. Obstructive jaundice was produced by bile duct ligation for 7 days. Zymosan (200 mg) was injected intraperitoneally and 4h later myeloperoxidase activity in the peritoneal fluid was measured to quantify neutrophil recruitment. Zymosan-induced neutrophil recruitment was significantly greater (more than two-fold) in bile duct-ligated rats than in sham-ligated or normal animals. Depletion of peritoneal cells significantly suppressed neutrophil recruitment after zymosan injection in all three groups, with no significant differences between the groups. In normal rats, replacement of their peritoneal cells by those from bile duct-ligated rats did not enhance zymosan-induced neutrophil recruitment. In contrast, bile duct-ligated rats treated with peritoneal cell replacement from normals showed significantly increased neutrophil recruitment after zymosan injection. In vitro neutrophil chemotaxis in response to formyl-Met-Leu-Phe was significantly enhanced in bile duct-ligated rats, compared with that in sham-ligated animals. The results suggest that local neutrophil recruitment in response to inflammation may be enhanced in obstructive jaundice and that increased neutrophil chemotactic activity, not macrophage activity, may play a prime role in the mechanism.

Animals↗

PubMedDate not supplied

Human neutrophil functions in obstructive jaundice.

BACKGROUND/AIMS: The effect of obstructive jaundice on neutrophil function has not been extensively studied. Therefore, the present study aimed at evaluating the effect of obstructive jaundice on human neutrophils. METHODOLOGY: Twelve patients with obstructive jaundice due to common bile duct obstruction underwent endoscopic biliary drainage. Neutrophil functions (chemotaxis and superoxide anion generation) were evaluated before and 7 days after drainage. RESULTS: Neutrophil chemotaxis in response to FMLP (formyl-methionyl-leucyl-phenylalanine) or interleukin-8 was abnormally increased before drainage, and was normalized after drainage. Similarly, enhanced superoxide anion generation in response to FMLP or phorbol myristate acetate before drainage was alleviated after drainage. CONCLUSIONS: The results suggest neutrophil overactivity in patients with obstructive jaundice. The ameliorating effect of biliary drainage on neutrophil overactivity might play a role in the prevention of postoperative complications.

Adult↗

PubMedDate not supplied

Endoscopic irradiation and parallel arrangement of Wallstents for hilar cholangiocarcinoma.

BACKGROUND/AIMS: The placement of two Wallstents in parallel seems to be a common solution for endoscopic technique in order to obtain bilateral hepatic drainage in patients with hilar biliary strictures. However, a biliary stricture at the hepatic confluence hinders the sequential delivery of multiple Wallstents. Intraductal irradiation has been shown to recanalize the cancerous stricture caused by cholangiocarcinoma. METHODOLOGY: We attempted to place two Wallstents in parallel by endoscopic means after endoscopic intraductal irradiation with a high-dose rate afterloading device in three patients with hilar cholangiocarcinoma. After the placement of two guidewires into the bilateral hepatic ducts, two Wallstents were sequentially delivered over the guidewires. RESULTS: Owing to adequate re-opening of the hilar bile ducts after irradiation, the delivery of the second Wallstent alongside the expanded first Wallstent could be readily accomplished in all of the patients without complications. Two Wallstents were placed so that their distal ends were juxtaposed in the common bile duct, ensuring good drainage. There were no signs of recurrent biliary obstruction in any of the patients during the follow-up period of 24 to 44 weeks. CONCLUSION: This endoscopic technique seems to be simple, safe, and reliable in obtaining bilateral hepatic drainage with Wallstents in patients with hilar cholangiocarcinoma.

Aged↗

PubMedDate not supplied

MR imaging in the evaluation of the therapeutic effect of B-RTO for gastric varices.

BACKGROUNDS/AIMS: Balloon-occluded retrograde transvenous obliteration (B-RTO) has become a new treatment option for gastric varices. In the present study, mid-term follow-up data after B-RTO were presented, and the role of magnetic resonance imaging (MRI) and MR-portography in the assessment of therapeutic effect was evaluated. METHODOLOGY: Twelve patients with gastric varices were treated with up to three sessions of B-RTO. The patients were followed up with MRI, MR-portography, and endoscopy for a mean of 12.3 months. RESULTS: In ten patients, one (n = 8) or two (n = 2) sessions of B-RTO were effective to produce immediate (< 2 weeks) variceal obliteration on MRI and MR-portography. Endoscopic confirmation of variceal eradication was obtained within three (n = 9) or six (n = 1) months after B-RTO in these patients. The remaining two patients who underwent three sessions of B-RTO showed only a significant reduction in variceal size immediately after B-RTO, but variceal obliteration was observed within three months with subsequent variceal eradication. There were no signs of exacerbation of gastric varices on MRI and endoscopy in any patient during the follow-up period. CONCLUSIONS: The results suggest that B-RTO is effective for the treatment of gastric varices. MRI and MR-portography may provide accurate assessment of therapeutic effect.

Aged↗