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Yukiko Ito

Publications and source records attributed to Yukiko Ito.

13 recordsLinked to original sources
PubMed2026

Development and Crossover Evaluation of an Artificial Intelligence-Assisted System for Solid Pancreatic Lesion Detection and Pancreatic Parenchyma Recognition in Endoscopic Ultrasonography (With Video).

BACKGROUND AND STUDY AIMS: Pancreatobiliary endoscopic ultrasonography (EUS) is technically demanding, and supervised training opportunities are limited. We developed an artificial intelligence (AI) overlay system for detecting solid pancreatic lesions (SPL) and recognizing pancreatic parenchyma (PP) and evaluated its effect on reader performance. PATIENTS AND METHODS: Across six centers, two deep learning-based models were trained using expert-annotated EUS frames. We then conducted a randomized, two-sequence, two-period crossover reader study in which eight endosonographers (five novices and three experts) interpreted image sets with and without AI assistance. The primary endpoint was superiority of sensitivity for SPL detection among novices; key secondary endpoints included specificity and PP recognition. RESULTS: From 118 patients, 120 SPL-positive/negative image sets and 160 PP-positive/negative image sets were constructed. Among novices, AI assistance improved SPL detection sensitivity (88.7% vs. 76.8%, p&#x2009;<&#x2009;0.001) and accuracy (86.4% vs. 78.7%), while specificity met the predefined noninferiority criterion (84.2% vs. 80.5%, p&#x2009;<&#x2009;0.001). For PP recognition, sensitivity increased numerically (86.3% vs. 83.3%) but did not meet the predefined superiority criterion (p&#x2009;=&#x2009;0.095); specificity met the noninferiority criterion (87.8% vs. 81.0%), and accuracy increased from 82.1% to 87.0%. Among experts, sensitivity was maintained for both tasks, whereas specificity increased with AI assistance. CONCLUSIONS: AI assistance improved SPL detection among novice endosonographers. For PP recognition, sensitivity increased without reaching statistical superiority, whereas specificity met the predefined noninferiority criterion. These findings support a potential adjunctive role for AI in EUS interpretation.

Humans↗
PubMed2006

Cholecystitis after metallic stent placement in patients with malignant distal biliary obstruction.

BACKGROUND & AIMS: Cholecystitis after metallic stent (MS) placement is an issue requiring attention. From our experience, cholecystitis seemed to occur mainly in patients with tumor involvement to the cystic duct orifice. The aim of the present study was to identify risk factors for cholecystitis in patients treated with covered or uncovered MS. METHODS: We analyzed 246 patients who received MS placement (covered MS in 171 and uncovered in 75) between August 1997 and May 2005 for the treatment of unresectable distal malignant biliary obstruction. Causative diseases were as follows: pancreatic cancer in 162, papillary cancer in 10, bile duct cancer in 41, and metastatic nodes in 33 patients. Tumor involvement to orifice of the cystic duct (OCD) was diagnosed based on cholangiography and intraductal ultrasonography. RESULTS: Cholecystitis after MS placement was found in 13 patients (5.3%). There was no significant difference in the incidence of cholecystitis between covered (5.8%) and uncovered (4.0%) MS. By univariate analysis, tumor involvement of the OCD, MS placed above the papilla, and stricture located at midportion were associated significantly with cholecystitis. By multivariate analysis, only tumor involvement of the OCD was a risk factor, with an odds ratio of 47.206 (95% confidence interval, 5.84-381.60). CONCLUSIONS: Cholecystitis after MS placement is associated with tumor involvement to the orifice of the cystic duct, regardless of the type of stent.

Aged↗
PubMed2005

Delayed development of hepatocellular carcinoma during long-term follow-up after eradication of hepatitis C virus by interferon therapy.

A 42-year-old Japanese man with liver cirrhosis by hepatitis C virus (HCV) had successful interferon therapy in May 1991. Since then, serum HCV-RNA and liver function tests had been negative. He had continued to drink more than 100 g/d of alcohol as before. In June 2003, a 5-cm tumor was found in the posterior segment of the liver. The tumor was curatively resected and the surgical specimen showed a well-differentiated hepatocellular carcinoma (HCC). Non-cancerous lesions of the liver revealed fibrosis at stage F3 with minimal to mild inflammation of grade A1. Heavy drinking may retard the dissolution of fibrosis and accelerate HCC development in patients with sustained virological response.

Adult↗
PubMed2005

Behavioral changes following antisense oligonucleotide-induced reduction of organic cation transporter-3 in mice.

The organic cation transporter-3 (OCT3) can transport monoamines, similar to neuronal monoamine transporters. Due to the lack of selective ligands, however, the functional role of OCT3 is still unknown. Thus, we investigated behavioral effects of antisense against OCT3 (AS) in mice. AS (0.075-0.25 microg/0.25 microl/h, for 7 days) dose-dependently decreased immobility time. Moreover, although neither AS (0.075 microg/0.25 microl/h, for 7 days) or imipramine (4 mg/kg, i.p.) were effective, imipramine (4 mg/kg, i.p.) significantly decreased immobility time in mice treated with AS (0.075 microg/0.25 microl/h, for 7 days). Additionally, AS (0.25 microg/0.25 microl/h, for 7 days) significantly increased locomotor activity induced by methamphetamine (1 mg/kg, s.c.), but did not affect spontaneous locomotor activity. These results suggest that OCT3 might become a novel molecular target to treat depression and other diseases related to monoaminergic neuronal systems.

Animals↗
PubMed2005

Ulinastatin for pancreatitis after endoscopic retrograde cholangiopancreatography: a randomized, controlled trial.

BACKGROUND & AIMS: Pancreatitis remains the major complication of endoscopic retrograde cholangiopancreatography (ERCP), and hyperenzymemia after ERCP is common. Because ulinastatin, a protease inhibitor, has proved effective in the treatment of acute pancreatitis, the aim of this study was to assess the efficacy of ulinastatin for the prevention of post-ERCP pancreatitis and hyperenzymemia. METHODS: In a multicenter, randomized, double-blind, placebo-controlled trial, patients undergoing a first ERCP were randomized to receive ulinastatin (150,000 U) or placebo by intravenous infusion for 10 minutes starting immediately before ERCP. All patients were hospitalized at least 24 hours after ERCP for evaluation of clinical symptoms. Serum pancreatic enzyme levels were measured before and at 4 and 18 hours after ERCP. The primary end point was the incidence of post-ERCP pancreatitis and the secondary objective was the occurrence of hyperenzymemia. RESULTS: A total of 406 patients were enrolled (204 in the ulinastatin group and 202 in the placebo group). There were no differences between the 2 groups regarding baseline characteristics, details of fluoroscopic findings, or endoscopic procedure. The incidence of hyperenzymemia was significantly lower in the ulinastatin group than in the placebo group (amylase, P = .011; lipase, P = .008). Six patients in the ulinastatin group and 15 patients in the placebo group developed pancreatitis (2.9% vs. 7.4%, P = .041). There was no case of severe pancreatitis in either group. Patients who received ulinastatin did not present any side effects related to the medication. CONCLUSIONS: Prophylactic short-term administration of ulinastatin decreases the incidence of pancreatitis and hyperenzymemia after ERCP.

Acute Disease↗
PubMed2005

Risk factors for pancreatitis in patients with common bile duct stones managed by endoscopic papillary balloon dilation.

OBJECTIVES: Endoscopic papillary balloon dilation has been accepted as a possible alternative to endoscopic sphincterotomy, especially in patients with impaired hemostasis. However, pancreatitis associated with endoscopic papillary balloon dilation has remained a controversial, serious issue. The aim of the study was to investigate the risk factors for postendoscopic papillary balloon dilation pancreatitis in a single-center study. METHODS: A total of 304 patients who underwent endoscopic papillary balloon dilation for the management of common bile duct stones were enrolled. The risk of postendoscopic papillary balloon dilation pancreatitis was evaluated and the risk factors were analyzed by univariate and multivariate analysis. Definition and grade of the severity of postendoscopic papillary balloon dilation pancreatitis were based on the 1991 consensus guidelines. RESULTS: Common bile duct was cleared in 292 of 304 patients (96%). Procedure-related pancreatitis occurred in 15 patients (5.0%). The grade was mild in 8 and moderate in 7. Two risk factors, stone diameter and contrast medium injection to the pancreas, were identified by univariate analysis. Finally, only the contrast medium injection to the pancreas was statistically significant by multivariate analysis. Prior history of pancreatitis was identified as a risk factor for postendoscopic papillary balloon dilation pancreatitis in previous studies, but this factor was not identified as a risk factor in our series. CONCLUSIONS: Although the pathogenesis of pancreatitis after endoscopic papillary balloon dilation remains unresolved, the unnecessary injection of contrast medium to the pancreas can certainly be considered to be associated with the increased risk of pancreatitis.

Aged↗
PubMed2004

Drug interaction between methamphetamine and antihistamines: behavioral changes and tissue concentrations of methamphetamine in rats.

Methamphetamine is a psychomotor stimulant, whereas first generation antihistamines cause sedation. Several studies have demonstrated that first generation antihistamines potentiate methamphetamine-induced psychomotor activation and two possible mechanisms have been postulated. One is blockage of the central histaminergic neuron system and the other is inhibition of dopamine reuptake. However, the exact mechanism is still controversial. In this study, we examined in behavioral tests the effects of selected antihistamines on methamphetamine-induced psychomotor activation in rats, and measured plasma and brain tissue concentrations of methamphetamine. We found that some antihistamines significantly potentiate methamphetamine-induced psychomotor activation in rats and that plasma and brain tissue concentrations of methamphetamine in rats treated with methamphetamine in combination with D-chlorpheniramine were markedly higher than those in rats treated with methamphetamine alone. These results suggest that the potentiating effects of antihistamines are due to not only central effects but also the alteration of the pharmacokinetics of methamphetamine.

Animals↗
PubMed2004

The altered disposition of methamphetamine in the model of methamphetamine-induced neurotoxicity.

Methamphetamine (METH) is a drug of abuse, causing neurotoxic effects in mammals. Many hypotheses have been proposed to explain the underlying mechanisms of METH-induced toxicity, based on neurochemical/neuroanatomical changes. However, the pharmacokinetic properties of METH in the METH-induced neurotoxic model have not yet been evaluated. Thus, we investigated plasma and tissue levels of METH in the METH-induced neurotoxic model. As a result, when METH is administered multiply (5 mg/kg 4 times at 2-h intervals) in male Wistar rats, plasma METH levels at the third and forth injections were significantly higher than those at the first. The tissue distributions of METH in the brain as well as in the kidney were significantly decreased in the third injections, suggesting the importance of decreased transport of METH into tissues. Alternatively, one week after the establishment of METH-induced neurotoxicity, plasma levels of METH were back to normal, although METH levels in brain microdialysates were significantly higher than those in normal animals. These results suggest that the altered pharmacokinetic properties of METH, due to the abnormal membrane transport/disposition of METH into both central and peripheral tissues, might partially affect the emergence of METH-induced neurotoxicity.

Animals↗
PubMed2003

gbx2 Homeobox gene is required for the maintenance of the isthmic region in the zebrafish embryonic brain.

We isolated cDNA clones for the zebrafish gbx2 gene, which is implicated in the establishment of the midbrain-hindbrain boundary (MHB) in other vertebrates. Spatially localized expression of gbx2 was observed at the MHB from 90% epiboly through to the hatching stage. Comparisons with the expression of otx2, wnt1, and krox20 showed that gbx2 is expressed in the anterior hindbrain. Ectopic expression of gbx2 by mRNA injection caused cyclopia or truncation of the fore- and midbrain and severely affected isthmic and cerebellar structures, while hindbrain formation was not significantly affected. At the molecular level, gbx2 suppressed the expression of otx2 in the fore/midbrain, six3 in the anterior forebrain, and MHB-specific genes such as eng2 and wnt1. In contrast, gbx2 did not down-regulate the expression of the hindbrain marker genes. Therefore, gbx2 specifically suppressed the formation of the entire fore/midbrain. Meanwhile, misexpression of otx2 suppressed the expression of gbx2 in the embryonic brain. Abrogation of gbx2 expression with an antisense morpholino oligonucleotide disrupted the midbrain/anterior hindbrain region, and these loss-of-function effects were rescued by activating the Gbx2 protein immediately after the end of gastrulation. Taken together, these results suggest that the zebrafish gbx2 gene is essential for the maintenance of MHB and/or the formation of the isthmic structure during somitogenesis, rather than for the MHB establishment during gastrulation. We also suggest that other factors, including gbx1, is required for the establishment of the MHB during gastrulation.

Amino Acid Sequence↗
PubMed2003

A simple method for sutureless gastrointestinal anastomosis in rat.

A simple tubing stent was attempted to test a model for sutureless gastrointestinal anastomosis in 6 male rats at the age of 15 weeks. In the 3rd and 4th weeks after the operation, X-ray examination demonstrated that the gastrointestinal passage in the anastomotic site was quite satisfactory. There was no incidence of anastomotic leakage. In the 6th week after the operation, there were no macroscopic or microscopic ruptures, nor were there any obstructions at the anastomotic site. This simple sutureless method was effective at preparing anastomosis in the gastrointestinal tract in the rat and could be applied to other small experimental animals.

Anastomosis, Surgical↗
PubMed2002

Birch-pollen sensitization in an area without atmospheric birch pollens.

OBJECTIVE: To clarify the incidence of individuals with a subclinical allergy to birch pollen and the possible allergic association between birch pollen and other allergens in areas without atmospheric birch pollen. METHODS: Birch-pollen-specific immunoglobulin E concentration in sera, together with those for some other inhaled and ingested allergens, was measured in 409 male and 525 female patients (an average age of 58.6 years, born and raised in an area without atmospheric birch pollen) with suspicious nose and/or throat allergies. Concomitantly, types and concentrations of pollen grains in the regional air were examined. RESULTS: Of 934 patients 13.2% showed birch-pollen-specific immunoglobulin E although no birch pollens were observed in the atmospheric air. The rate was relatively low in comparison with those for clinically important inhaled allergens in this area: 35.2% for Japanese cedar pollen, 24.7% for house dust and 23.2% for cypress pollen. Spearman's rank correlation analysis and logistic regression analysis revealed that birch pollen correlated strongly with apple and some foodstuffs commonly ingested by all age groups (rho>0.6000, odds ratio>27.191). CONCLUSIONS: A considerably large number of patients with a subclinical allergy to birch pollen exist in an area without atmospheric birch pollen. Measurement of specific immunoglobulin E to birch pollen is important even in such areas for screening and diagnosing patients with oral allergy syndrome.

Adolescent↗
PubMed2002

[Gramineae pollen dispersal and pollinosis in the city of Hisai in Mie Prefecture. A 14-year study of gramineae pollen dispersal and cases of sensitization to gramineae experienced at an allergy clinic over a 15-year period].

(1) A study of Gramineae pollen dispersal was conducted in Hisai, Mie Prefecture from 1987 to 2000; Gramineae pollen counts did not increase, with an average of 133 during the 14 years. There was two or three peaks in the annual dispersal period, suggesting that symptoms in late May, late July to early August, and late September are important for diagnosis of Gramineae pollinosis in this region. (2) Changes in the frequencies of sensitization to Gramineae pollen and Gramineae pollinosis were studied in 756 allergy clinic patients with nasal allergies examined over a 15-year period from 1986 to 2000. Results for the frequency of sensitization every 5 years came to 7.9, 22.4, and 23.3% and that of Gramineae pollinosis were 4.8, 10.3, and 12.1%. Both frequencies tended to increase after 1990. Out of 135 patients with sensitization to Gramineae, 88.1% had multiple sensitization to Japanese cedar and 54.8% had sensitization to Japanese cedar as well as house dust or mites. Patients sensitized only to Gramineae accounted for 5.9% of total patients. About half of the patients with sensitization to Gramineae developed pollinosis. As the CAP RAST score increased, so did the increase of pollinosis.

Adolescent↗