PubMed Health⌕ Search

Biomedical subjects

Hiroshi Araki

Publications and source records attributed to Hiroshi Araki.

13 recordsLinked to original sources
PubMed2006

Procedural implications of intravascular ultrasound morphologic features of chronic total coronary occlusions.

Although the success rates of percutaneous coronary intervention of chronic total occlusions (CTOs) have improved, morphologic features are not well known. We analyzed experience at 4 centers where intravascular ultrasound (IVUS) was performed in 67 native artery CTO lesions (mean CTO duration 6.3 months) just after the lesion was crossed with a guidewire (n = 7) or after dilatation with a 1.5-mm (n = 46) or 2.0-mm (n = 14) balloon. IVUS detected calcium somewhere in the CTO in 96%; however, only 68% had mild calcium. IVUS identified a proximal end of the CTO in all lesions, but a distal end of the CTO in only 50%. An intramural hematoma was observed in 34% of CTOs, suggesting that the guidewire frequently entered the medial space during successful recanalization. CTOs were longer, vessel area was smaller, and total calcium index was greater in lesions with hematomas (p = 0.003, 0.05, and 0.03, respectively). Inadequate reflow after the procedure was observed in 9% and was associated with longer lesions and intralesional calcium. CTO length as measured with angiography was shorter than the length as measured with IVUS (p = 0.02). Calcium was detected on the angiogram in 61% (p = 0.054 vs IVUS). Most typical angiographic findings associated with a low rate of procedural success were not associated with different IVUS morphologies. In conclusion, CTO lesions had multiple small calcium deposits, intramural hematomas were common and were indicative of guidewire penetration into the medial space during the CTO procedure, especially in long calcified lesions in smaller vessels, and inadequate reflow after the procedure was correlated with more complex CTO morphology.

Aged↗
PubMed2006

Clinical analysis of gastroesophageal reflux after PEG.

BACKGROUND: It is difficult to predict whether or not gastroesophageal reflux (GER), such as aspiration or vomiting, will occur after PEG. OBJECTIVE: To identify factors that would support the prediction of aspiration after PEG. DESIGN: Case-control study. SETTING: Patients who underwent PEG from February 1998 to June 2005 in our hospital. PATIENTS: The study included 178 patients. INTERVENTIONS: Endoscopic observation was carried out during PEG tube placement and at PEG tube replacement to determine the presence of hiatus hernia and/or reflux esophagitis. MAIN OUTCOME MEASUREMENTS: Gastric emptying and GER index (GERI) were measured by using a radioisotope technique. RESULTS: The patients were divided into 2 groups: the non-GER (NGER) group (n = 108), who had no symptoms of GER, and the GER group (n = 70), who showed these symptoms. No significant differences were observed between the groups in age, sex, morbidity, the presence of reflux esophagitis at PEG tube placement, gastric emptying, or serum albumin levels. The presence of a hiatus hernia (P = .028) and reflux esophagitis grading Los Angeles classification C or D (P = .008) were significantly more frequent in the GER group compared with the NGER group. The GERI was also significantly higher in the GER group than in the NGER group (P < .0001). CONCLUSIONS: The presence of hiatus hernia, severe reflux esophagitis, and a high GERI might be predictive factors of aspiration or vomiting after PEG tube placement.

Aged↗
PubMed2006

Effect of adiponectin on murine colitis induced by dextran sulfate sodium.

BACKGROUND & AIMS: Adiponectin, an adipose tissue-derived hormone, exhibits anti-inflammatory properties and has various biological functions, such as increasing insulin sensitivity, reducing hypertension, and suppressing atherosclerosis, liver fibrosis, and tumor growth. The aim of the present study was to determine the effect of adiponectin on intestinal inflammation. METHODS: We investigated the effect of adiponectin on dextran sulfate sodium (DSS)-induced colitis by using adiponectin-knockout (APN-KO) mice and an adenovirus-mediated adiponectin expression system. We also examined the contribution of adiponectin deficiency to trinitrobenzene sulfonic acid (TNBS)-induced colitis. In vitro, we examined the effect of adiponectin on intestinal epithelial cells. RESULTS: After administration of 0.5% DSS for 15 days, APN-KO mice developed much more severe colitis compared with wild-type mice. The messenger RNA expression levels of chemokines were significantly higher in the colonic tissues of DSS-treated APN-KO mice compared with wild-type mice, accompanied by increased cellular infiltration, including macrophages. Adenovirus-mediated supplementation of adiponectin significantly attenuated the severity of colitis, but there were no differences in the severity of TNBS-induced colitis between the 2 groups. Adiponectin receptors were expressed in intestinal epithelial cells, and adiponectin inhibited lipopolysaccharide-induced interleukin-8 production in intestinal epithelial cells. CONCLUSIONS: Adiponectin is protective against DSS-induced murine colitis, probably due to the inhibition of chemokine production in intestinal epithelial cells and the following inflammatory responses, including infiltration of macrophages and release of proinflammatory cytokines.

Adiponectin↗
PubMed2006

Less morbidity after pancreaticoduodenectomy of patients with pancreatic cancer.

OBJECTIVES: The pancreaticoduodenectomy with extended resection has been frequently performed in patients with pancreatic cancer in Japan. One result of this additional surgical stress may be that postoperative complications in patients with pancreatic cancer are more frequent than in patients with periampullary cancer. METHODS: The 198 patients with pancreatic and periampullary cancer underwent pancreaticoduodenectomy. The operative mortality and morbidity between patients with pancreatic and periampullary cancer were compared, and the risk factors of postoperative complications and in-hospital death were determined. RESULTS: Patients with pancreatic and periampullary cancer made up 52% and 48% of total patients. The duration of surgery and volume of intraoperative blood loss were significantly higher in patients with pancreatic cancer than in patients with periampullary cancer. Additional organ resections were frequently performed in patients with pancreatic cancer. However, significantly lower morbidity rates were observed in patients with pancreatic cancer. Among all complications evaluated, pancreatic fistula and abdominal abscess were found less frequently in patients with pancreatic cancer. Logistic regression analyses showed a positive correlation between periampullary cancer and an increased risk of complications, pancreatic fistula, and abdominal abscess. The in-hospital mortality rate has significantly reduced since 2000. When pancreatic fistula was clinically diagnosed, we immediately started a closed lavage using continuous administration of natural saline at 1000 to 4000 mL/d, after exchange of a nasogastric tube drain. CONCLUSION: Pancreaticoduodenectomy for patients with pancreatic cancer can be a safe procedure in spite of surgical stress. Further surgical strategies will be needed to reduce postoperative complications, especially in patients with periampullary cancer.

Abdominal Abscess↗
PubMed2005

Surgical influence of pancreatectomy on the function and count of circulating dendritic cells in patients with pancreatic cancer.

BACKGROUND: Dendritic cells (DCs) are important for an immune surveillance. Myeloid DCs (DC1) are important for an effective antitumor immune system. The function and count of circulating DC1 (cDC1) in hosts with a malignant tumor would be defective. This study focused on analyzing the immunological features of cDC1 in patients with pancreatic cancer during the perioperative period. MATERIALS AND METHODS: Thirty-two pancreatic cancer patients who underwent pancreatectomy and 18 age-matched healthy individuals as controls were enrolled in this study. The perioperative cDC count, the stimulatory capacity of cDC1 against allogeneic T cells and TGF-beta1 level in the serum were measured. The cDC count was measured at 12 months after the operation. RESULTS: The preoperative cDC1/cDC2 ratio, cDC1 count, and stimulatory capacity of cDC1 were impaired in patients in comparison to controls (P<0.05). The serum TGF-beta1 level was significantly higher in patients than controls (P<0.001). The stimulatory capacity of cDC1 recovered after pancreatectomy (P<0.05). The serum TGF-beta1 level significantly decreased after the operation (P<0.05); however, they were still significantly higher than controls (P<0.05). Although the cDC1/cDC2 ratio and the cDC1 count did not increase after the pancreatectomy, they recovered as the controls' level at 12 months after the pancreatectomy in disease-free patients (P<0.05) and the serum TGF-beta1 level in those patients at 12 months after the operation significantly decreased compared with those at the postoperative period (P<0.05). CONCLUSION: Surgical resection of pancreatic cancer could be associated with improved cDC1 function. When a patient remained disease free, the recovery of cDC1 counts was observed approximately 12 months after pancreatectomy. Further strategy will be needed to improve immune function in patients with pancreatic cancer.

Aged↗
PubMed2005

Synthesis of SiC nanowires with in-situ deposition of carbon coating.

SiC nanowires are effective reinforcement materials in ceramic matrix composites. A compliant coating such as carbon on nanowires is necessary in order to moderate the nanowire/matrix interfacial bounding for taking the most advantages of SiC nanowires. SiC nanowires with an in-situ deposition of carbon shell coating were fabricated by a novel chemical vapor growth process. Highresolution transmission electron microscopy examinations showed that the nanowires consisted of a single crystal beta-SiC core with an amorphous carbon shell 2-5 nm in thickness. The nanowires were straight with a length generally over 10 microm and a diameter 15-150 nm. The growth direction of the core SiC nanowires is (111). A simple three-step growth model for SiC nanowires was proposed based on a vapor-solid growth mechanism. Because the carbon-coated nanowires were grown directly on continuous Tyranno-SA SiC fibers, in-situ application of the present technique on the fabrication of SiC nanowire-reinforced SiC/SiC composites is expected.

Carbon↗
PubMed2005

The latest wire technique for chronic total occlusion.

If patency is restored after chronic total occlusion (CTO), it can be maintained over the long term by implanting drug-eluting stents. The cause of unsuccessful percutaneous coronary intervention is usually failure of the wire to cross the site of CTO. The objective of this article is to describe the latest wire techniques for CTO. As for wire selection, CTO should generally be treated with hard-tipped spring wires, preferably Conquest Pro series (Asahi Intec). According to the penetrating strategy, the course of a blood vessel with CTO is established preoperatively and the wire is advanced based on the imaging data with minimum rotation (a torque of +/- 90 degrees or less). If the operator encounters divergence between the preoperative CTO image and the actual course of the coronary artery, the parallel wire technique should be used. With this method, a wire which enters the subintimal space is left there, and a second wire is inserted along it to find a new channel. When this technique is successful, the following findings are often noted: 1) the second wire crosses over the first one in the CTO; 2) the second wire shows more acute curve than the first wire; 3) the second wire penetrates the lesion from the outer curvature of the coronary artery and then is advanced along the same curvature of the vessel. Indeed, the second wire should be operated intentionally to achieve these findings so that the probability of success increases and the duration of the procedure is shortened.

Blood Vessel Prosthesis Implantation↗
PubMed2005

[Assessment of immunotoxicity of irinotecan determined by the novel method, by which productivity of TNF-alpha from whole blood is stimulated by lipopolysaccharide].

Irinotecan hydrochloride shows much different responses in each patient, and it has severe adverse effects. Therefore, a sensitive marker for the side effect of irinotecan on immunotoxicity may be able to prevent the severe complications by the early detection. We have recently developed a method to assess the immunotoxicity by measuring the productivity of TNF-alpha from whole blood containing monocytes when stimulated by lipopolysaccharide. By using this method, the effects of continuous low-dose irinotecan therapy on immunotoxicity were assessed in 10 patients with advanced gastric or colon cancer. When compared this method with the others such as white blood cell count, lymphocyte blastoid transformation by phytohem agglutinin (PHA), and natural killer cell activity in terms of the sensitivity, immunotoxicity by this method was found earlier than the other methods. Because our original method is easy to perform and sensitive as compared to the conventional methods, it can be widely used as one of the laboratory tests useful for patients treated with immunosuppressive agents.

Adult↗
PubMed2003

[3D-CRT and intensity modulated radiation therapy (IMRT)].

Three-dimensional conformal radiation therapy (3D-CRT) conforms a high dose region closer to the target volume than does 2D radiation therapy. IMRT is the advanced form of 3D-CRT. With IMRT technique, using multiple intensity modulated beams, one can deliver a high dose of radiation to the target and a low dose to the surrounding normal structures. IMRT planning provides improved tumor target coverage when compared to 3D-CRT treatment planning. There is significant sparing of critical structures and other normal tissues. IMRT also produces dose distributions capable of delivering different dose prescriptions to multiple targets, providing a new opportunity for differential dose painting to increase the dose selectively to specific image-defined regions. Preliminary findings indicate that IMRT is a new clinically feasible tool in radiation oncology. The initial results of clinical studies demonstrate reduced xerostomia in head and neck cancer and also effectively reduced acute and late occurring toxicities, improving the QOL of patients treated for prostate cancer. According to these studies, IMRT will allow dose escalation, leading to better tumor control without normal tissue damage. On the other hand, there are some problems for IMRT in Japan: There are few medical physicists, which results in radiation technologists playing most clinical technological roles, including some dosimetrical and physical activities. Social recognition and economical and legal support for medical physicists should be established in providing better patient care services.

Humans↗
PubMed2002

Metachronous colon tumors: risk factors and rationale for the surveillance colonoscopy after initial polypectomy.

PURPOSE: We analyzed the possible risk factors for metachronous colon tumors after endoscopic resection of initial tumors. METHODS: Three hundred and twenty-one patients entered the surveillance study after colonoscopic resection of initial tumors between 1985 and 1999. Histology of initial tumors was adenoma in 214 patients and carcinoma in 107 patients. Solitary tumor was observed in 196 patients and multiple tumors in 125 at initial endoscopy. The median surveillance period was 39 (range, 12-112) months, and the median frequency of surveillance colonoscopy was three (range, 2-10) times. RESULTS: Metachronous neoplasms were identified in 114 of 321 surveillance cases (36%). In the 114 cases, the number of patients with metachronous adenoma was 103 (90%) and that of carcinoma was 11 (10%). Clinical characteristics at entry - including age, gender, multiplicity of polyp, histology of polyp, and site of polyp - were not different between patients with metachronous tumors and those without metachronous tumors. Kaplan-Meier analysis revealed that patients with a histology of carcinoma and those with multiple polyps at entry developed metachronous tumors significantly earlier than did patients with initial adenomas and initial solitary polyp, respectively ( P<0.001, P<0.001). However, other characteristics at entry did not produce significant differences in the rate of the development of metachronous tumors using Kaplan-Meier analysis. Proportional hazards model analysis revealed that histology of the initial tumor as carcinoma (relative risk, 1.690, 95% confidence interval, 1.118-2.555) and multiplicity (1.472, 1011-2.143) were significant risk factors for metachronous colon tumors. The 75%, 50%, and 25% metachronous tumor-free periods after initial polypectomy were 14, 21, and 39 months, respectively. CONCLUSIONS: These results may help optimizing surveillance strategies for metachronous colon tumors and raising the economic benefit of colonoscopy.

Adenocarcinoma↗
PubMed2002

[A new combination therapy with low-dose FP and daily oral administration of low-dose etoposide--a report of 2 cases].

We report 2 patients with advanced gastric cancer treated with a new combination chemotherapy of low-dose FP and daily oral administration of low-dose etoposide. Patient 1 was an 84-year-old man. He was diagnosed with cancer of the remnant stomach with multiple liver metastases. For eight months, he was treated as an outpatient and his performance status (PS) stayed at stage 1. Patient 2 was a 67-year-old man with lymph node metastasis of the lung. For the first 6 weeks, he was treated under hospitalization and for the following 10 months he was treated as an outpatient. His PS remained in stage 1 and blood CEA value fell from 2,420 ng/ml to 46.9 ng/ml. Upper gastrointestinal series showed a recovery of the extension of his lower gastric body. Both cases were so-called prolonged NC. From the viewpoint of patient QOL, this new combination is a possible candidate for a more effective chemotherapy.

Adenocarcinoma↗