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Biomedical subjects

Ichiro Yoshikawa

Publications and source records attributed to Ichiro Yoshikawa.

At least 19 recordsLinked to original sources
PubMed2006

Comparison of glucagon and scopolamine butylbromide as premedication for colonoscopy in unsedated patients.

PURPOSE: Premedication with glucagon or hyoscyamine is reported to be effective in reducing colonic spasm. However, these drugs can be associated with unfavorable events. This prospective study was designed to compare the effects of premedication with glucagon with those of scopolamine butylbromide on cardiopulmonary parameters, intubation time, and patient discomfort in unsedated patients undergoing diagnostic colonoscopy. METHODS: One hundred consecutive adult patients (65 males) undergoing colonoscopy without sedation were randomized to receive 1 mg of glucagon (n = 50) or 20 mg of scopolamine butylbromide (n = 50), intramuscularly. Physiologic changes, including systolic blood pressure, heart rate, and oxygen saturation, were monitored before colonoscope insertion and at three-minute intervals during colonoscopy. The percentages of completed procedure and time to cecal intubation were recorded. Patients were asked to rate pain by using a five-point pain score (0 = no pain; 4 = severe pain). RESULTS: The percentages of completed procedure (96 vs. 98 percent), time to cecal intubation (16.3 vs. 14.5 minutes), and pain score (1.7 vs. 1.5) did not differ significantly between two groups. An increase in heart rate of more than ten beats per minute from baseline during colonoscopy occurred significantly more often in scopolamine group (44 percent of 50 patients) than in the glucagon group (12 percent of 50 patients; P = 0.0004). There were no significant differences between the two study groups with regard to changes in systolic blood pressure and decrease in oxygen saturation during colonoscopy. CONCLUSIONS: Premedication with 1 mg of glucagon facilitates favorable examination with respect to physiologic changes compared with 20 mg of scopolamine. These features favor glucagon as the preferred premedication for patients undergoing colonoscopy.

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PubMed2006

Grasping forceps-assisted endoscopic mucosal resection of early gastric cancer with a novel 2-channel prelooped hood.

BACKGROUND: Endoscopic mucosal resection with a cap-fitted panendoscope (EMRC) such as a soft prelooped hood is a useful, effective, and safe technique. One problem with this method is that the lesion cannot always be maintained in the center of the cap because the procedure is performed blindly after aspiration. OBJECTIVE: We developed a 2-channel prelooped hood that facilitates EMRC while simultaneously allowing both grip of the center in the lesion and irrigation of the aspiration site and evaluated the usefulness of this end hood for early gastric cancer. DESIGN: Retrospective study. SETTING: Between August 2003 and October 2004, patients underwent our novel EMR. PATIENTS: Twelve cases of early gastric cancer. INTERVENTIONS: Two side holes were fabricated by drilling in the cap portion of a conventional soft prelooped hood, and then the irrigation tube and the accessory channel tube were glued to the exterior surface of the holes. We placed the fabricated transparent hood at the tip of the endoscope and performed grasping forceps-assisted endoscopic aspiration mucosectomy. MAIN OUTCOME MEASUREMENTS: Accurate aspiration and the rate of en bloc resection. RESULTS: We obtained a satisfactory field of view and accurate aspiration in the center of the tumor in all lesions. The rate of en bloc resection was 91.7% (11/12). LIMITATIONS: Gastric intramucosal cancer. CONCLUSION: Grasping forceps-assisted endoscopic mucosal resection with a novel 2-channel prelooped hood is safe and useful for mucosal resection of intramucosal cancers less than 20 mm and may help center the lesion in the cap before resection.

Adenocarcinoma↗
PubMed2006

A novel method of endoscopic submucosal dissection with blunt abrasion by submucosal injection of sodium carboxymethylcellulose: an animal preliminary study.

BACKGROUND: Endoscopic submucosal dissection (ESD), particularly the process of submucosal incision with a knife, is technically difficult and carries a high risk of perforation. Submucosal injection of a viscous substance, eg, jelly, obviates the need of submucosal incision with a knife. Sodium carboxymethylcellulose (SCMC), known as cellulose gum, is highly viscous when dissolved in water. OBJECTIVE: To evaluate the efficacy and the safety of ESD by submucosal injection of SCMC solution in a porcine stomach. DESIGN AND SETTING: A prospective, single-center study. INTERVENTIONS: The viscosity of various concentrations (0.5%-3.5%) of SCMC was measured by a viscometry. First, we injected 10 mL of various concentrations of SCMC solution into the submucosal layer of resected porcine stomachs in vitro and examined whether the submucosal injection dissected the mucosal layer from the muscular layer by EUS. Second, we performed ESD by injecting, with an 18-gauge needle, the SCMC solution into the submucosal layer of the stomach in white domestic pigs in vivo to evaluate the efficacy and the safety of SCMC for ESD. MAIN OUTCOME MEASUREMENTS AND RESULTS: Submucosal injection of the SCMC solution dissected most of the mucosal layer from the muscular layer at the concentration above 2.0%. We, therefore, decided to use 2.5% SCMC for ESD with a 18-gauge needle to ensure dissection. Submucosal injection of 2.5% SCMC dissected the mucosal layer from the muscular layer without complications, such as massive bleeding or perforation, in white domestic pigs. Histologically, injection of 2.5% SCMC revealed no damage to the muscular layer and surrounding tissue. LIMITATIONS: Our novel injection technique was evaluated in an animal model with a normal stomach; it was relatively easy to approach the target mucosa. CONCLUSIONS: ESD by submucosal injection of viscous SCMC solution appeared to be an easy, safe, and technically efficient method for dissection of gastric lesions.

Animals↗
PubMed2005

Repeated injections of energy in the first 600 ms of the giant flare of SGR 1806-20.

The massive flare of 27 December 2004 from the soft gamma-ray repeater SGR 1806-20, a possible magnetar, saturated almost all gamma-ray detectors, meaning that the profile of the pulse was poorly characterized. An accurate profile is essential to determine physically what was happening at the source. Here we report the unsaturated gamma-ray profile for the first 600 ms of the flare, with a time resolution of 5.48 ms. The peak of the profile (of the order of 10(7) photons cm(-2) s(-1)) was reached approximately 50 ms after the onset of the flare, and was then followed by a gradual decrease with superposed oscillatory modulations possibly representing repeated energy injections with approximately 60-ms intervals. The implied total energy is comparable to the stored magnetic energy in a magnetar (approximately 10(47) erg) based on the dipole magnetic field intensity (approximately 10(15) G), suggesting either that the energy release mechanism was extremely efficient or that the interior magnetic field is much stronger than the external dipole field.

Journal Article↗
PubMed2005

Lugol chromoendoscopy as a diagnostic tool in so-called endoscopy-negative GERD.

BACKGROUND: Esophageal mucosal breaks are found in less than half of patients with typical reflux symptom. Thus, endoscopy appears to be an insensitive test for GERD. Lugol chromoendoscopy has been used to detect early esophageal cancer, which is difficult to recognize by routine observation without dye staining. The aim of this study was to determine the efficacy of Lugol chromoendoscopy in the diagnosis of so-called endoscopy-negative GERD (ENRD). METHODS: The study was conducted with 61 patients (21 women; mean age of 59.8 years) with reflux symptoms and 42 controls (15 women; mean age, 65.0 years). In the absence of any esophageal mucosal abnormalities at conventional endoscopy, Lugol's iodine solution was sprayed onto the esophageal surface, followed by evaluation of the staining pattern. When Lugol-unstained streaks were observed at chromoendoscopy, biopsy specimens were obtained from unstained streaks and from adjacent stained mucosa. Histologic evaluation included basal cell hyperplasia, papillary length, and cellular infiltration. RESULTS: Twenty-two (36%) of 61 patients with reflux, and 4 (10%) of 42 controls had visible esophagitis by conventional endoscopy. Lugol chromoendoscopy was performed in the remaining 39 patients and 38 controls. The entire esophageal mucosa was uniformly stained dark brown in 20 patients with reflux and 37 controls. In the remaining 19 patients with reflux and in one control, several unstained streaks were observed in the distal esophagus (p < 0.0001). Histologically, Lugol-unstained mucosa showed a significantly thicker basal cell layer (30.9% +/- 7.6% vs. 12.3% +/- 4.5% of total epithelial thickness, mean +/- standard deviation [SD], p < 0.01) and longer papillae (57.9% +/- 12.6% vs. 38.1% +/- 12.6% of total epithelial thickness, mean [SD], p < 0.01) compared with stained mucosa. In addition, infiltration of lymphocytes in the epithelium was significantly increased in unstained mucosa than in stained mucosa (p < 0.01). CONCLUSIONS: Visible unstained streaks by Lugol chromoendoscopy seem to be indicative of mucosal injury, which was not detectable by conventional endoscopy. Lugol chromoendoscopy is simple and could be useful for the diagnosis of ENRD. This method could be appealing for the endoscopist as it is easy, safe, and can be performed at the same endoscopic session.

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PubMed2004

Endoscopic hemostatic treatment under irrigation for upper-GI hemorrhage: a comparison of one third and total circumference transparent end hoods.

BACKGROUND: Endoscopic hemostasis for upper-GI hemorrhage often is difficult to achieve if the view of the bleeding lesion is poor because of the presence of mucus, blood, and clots. An end hood that facilitates endoscopic hemostatic procedures while simultaneously allowing irrigation of the bleeding site was designed by us. Based on this design, a one-third partial irrigating end hood was developed, and its usefulness for treatment of non-variceal hemorrhage was evaluated. METHODS: The end hood was fabricated by drilling a side hole in the cap portion of a transparent end hood. An irrigation tube was glued to the exterior surface over the hole. A "total" (type 1) and a "one-third partial" (type 2) transparent end hood were fabricated. These differ with respect to the proportion of the endoscope circumference that is hooded by the device. The fabricated transparent end hood was placed on the tip of a standard endoscope. With the end hood in place, endoscopic hemostatic treatment under irrigation was performed in 35 patients (type 1 end hood, 18; type 2, 17) with non-variceal upper-GI hemorrhage. OBSERVATIONS: Hemostatic treatment was enhanced by simultaneous irrigation beneath the end hood, and hemostasis was successfully achieved in 34 of 35 cases. The time required to achieve hemostasis was significantly shorter in the type 2 group than the type 1 group (median 11.8 vs. 16.9 minutes; p < 0.05). CONCLUSIONS: The end hood was extremely useful for endoscopic hemostatic treatment under irrigation. The "one-third partial" end hood is superior to the total end hood in terms of duration of time required to achieve hemostasis.

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PubMed2004

EMR of upper GI lesions when using a novel soft, irrigation, prelooped hood.

BACKGROUND: EMR with a cap-fitted endoscope, including a soft, prelooped hood, is a useful, effective, and safe technique. One problem with this method, however, is that the lesion cannot always be kept in the center of the cap because the procedure is performed blindly after aspiration. A soft, prelooped hood with attached irrigation tube was developed. The usefulness of this device for EMR of upper-GI intramucosal cancers was evaluated. METHODS: The end-hood piece was fabricated by drilling a side hole in the cap portion of a conventional soft, prelooped hood and then attaching an irrigation tube with glue to the exterior surface of the hole. The fabricated transparent hood was placed at the tip of an endoscope, and aspiration mucosectomy under irrigation was performed in 15 patients with upper-GI intramucosal cancer. When the field of view at the aspiration site was obscured by oozing blood, the site was irrigated. RESULTS: A satisfactory view was obtained of all lesions. The mean diameter of specimens was 24.5 mm (interquartile range: 15-35). The proportion of en bloc resected lesions was 86.7% (13/15). Bleeding was the only complication (4/15; 26.7%) and was controlled by using endoscopic hemostatic techniques under irrigation. CONCLUSIONS: EMR when using the soft, prelooped hood with irrigation tube is effective and safe for intramucosal cancers 20 mm or less in diameter.

Aged↗
PubMed2003

Endoscopic treatment of upper GI hemorrhage with a novel irrigating hood attached to the endoscope.

BACKGROUND: Despite advances in endoscopic treatment methods for upper GI hemorrhage, hemostasis is often difficult to achieve, particularly when the endoscopic view at the site of hemorrhage is poor because of the presence of mucus and blood. The investigators developed an end hood that facilitates endoscopic hemostatic procedures while simultaneously allowing irrigation of the bleeding site. The usefulness of this end hood for treatment of upper GI hemorrhage, excluding hemorrhage from varices, was evaluated. METHODS: The end-hood piece was fabricated by drilling a side hole in the cap portion of a conventional transparent hood. An irrigation tube then was glued to the exterior surface of the hole. The fabricated transparent hood was placed on the tip of an endoscope. With the hood piece in place, hemoclip placement and other endoscopic hemostatic procedures were performed in 15 patients with nonvariceal upper GI hemorrhage. RESULTS: Hemostasis was successfully achieved in all cases. In all cases of active hemorrhage, hemostatic treatment was enhanced by simultaneous irrigation beneath the hood. The median time required for the hemostatic procedure with the attached hood was 4.8 minutes. CONCLUSION: The end-hood irrigation device and technique facilitate endoscopic hemostatic treatment of nonvariceal upper GI hemorrhage.

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