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Biomedical subjects

M Itoh

Publications and source records attributed to M Itoh.

At least 541 records · Page 30Linked to original sources

Molecular dissection of tight junctions.

In epithelial and endothelial cells, the tight junction (TJ) seals cells to create a primary barrier to the diffusion of solutes across the cell sheet, and it also works as a boundary between the apical and basolateral membrane domains to create their polarization. An integral membrane protein working at TJ is postulated to exist, but it has remained elusive for quite some time. Most recently, using mAbs, we identified an integral membrane protein named occludin that was exclusively localized at TJ both in epithelial and endothelial cells. Here we overview our recent studies on the structure and function of occludin.

Animals↗

In vivo macrophage-stimulation activity of the enzyme-degraded water-soluble polysaccharide fraction from a marine alga (Gracilaria verrucosa).

The water-soluble polysaccharide fraction from Gracilaria verrucosa (GWS) has been reported to increase the phagocytic activity of mice [Yoshizawa et al., Nippon Shokuhin Kogyo Gakkaishi, 41, 557-560 (1994)]. In this study, the macrophage-stimulation activity of enzyme-degraded GWS (GWS-E) was investigated by intraperitoneally and orally administering GWS-E to mice. The intraperitoneal administration of GWS-E increased the number of peritoneal exudate cells (PEC), and increased the phagocytic activity and oxygen radical-secreting activity (spontaneous chemiluminescence) of PEC. This administration could also stimulate splenic macrophages (SPM), increasing radical-secreting activity. When GWS-E was administered orally, the radical-secreting activity of PEC and SPM increased. In this case of oral administration, the activity of SPM increased in a dose-dependent manner, while that of PEC had an optimum dose. These results indicate that GWS-E had macrophage-stimulation activity in vivo and would be suitable as a source for a physiologically functional food with protective and immunopotentiating activity.

Administration, Oral↗

Analysis of plasma metabolites during human PET-studies with three receptor ligands, [11C]YM-09151-2, [11C]doxepin and [11C]pyrilamine.

Carbon-11 labeled metabolites in human plasma were analyzed by high-performance liquid chromatography during positron emission tomography (PET) studies using the dopamine D2 ligand [11C]YM-09151-2 as well as the histamine H1 ligands [11C]doxepin and [11C]pyrilamine. For all the three tracers, blood clearance of the radioactivity was extremely rapid after an i.v. injection. The plasma protein-binding of [11C]YM-09151-2 and [11C]doxepin had protective effects upon the metabolic alteration of the ligands, whereas [11C]pyrilamine was free from the protein-binding and immediately degraded. The degradation of [11C]doxepin was more rapid in epileptic patients on medication than in normal subjects. These results indicate that analysis of metabolites in the plasma is necessary to determine the accurate arterial input function for quantitative PET measurement.

Adult↗

Total obliteration of colonic lumen by localized giant inflammatory polyposis in ulcerative colitis: report of a Japanese case.

Although inflammatory polyposis of the colon is a recognized local complication of ulcerative colitis, giant inflammatory polyposis that totally obliterates the colonic lumen is uncommon, and most of the patients have been from Western countries. We report a Japanese man who had localized giant inflammatory polyposis that obstructed the retrograde flow of barium in a double-contrast barium enema study at the splenic flexure in ulcerative colitis. After resection by total proctocolectomy and ileostomy, pathological examination of the specimen confirmed localized giant inflammatory polyposis in the descending colon and spelnic flexure without malignancy.

Barium Sulfate↗

A case of myocarditis associated with IDDM.

We report a case of diabetic ketoacidosis (DKA) complicated by acute myocarditis, which was confirmed by cardiac biopsy. A 26-year-old man was hospitalized with severe DKA. On admission, nonspecific ST-T change was noted on the electrocardiogram (ECG). The patient's levels of creatine phosphokinase (CPK) and glutamic oxaloacetic transaminase were slightly elevated, but he did not complain of chest discomfort or symptoms of heart disease. On the first day after admission, ST-T elevation was noted on ECG during treatment of DKA. By cardiac angiography and cardiac biopsy, coronary heart disease was ruled out and postmyocarditic change was histologically confirmed. An episode of upper respiratory viral infection before the onset of acute diabetes suggested that the patient suffered from viral-induced myocarditis and consequent development of IDDM. This possibility was confirmed by the clinical course of ECG change, with elevated CPK and lactate dehydrogenase and a slightly elevated antibody titer for echovirus.

Adult↗

Effects of the anti-gastric secretory drugs IT-066 and omeprazole mitogenic activities in the gastric juice of the rat.

BACKGROUND: Salivary epidermal growth factor (EGF) retains its biologic function in gastric juice and may play a physiologic role. Little is know, however, about the existence of mitogens other than EGF and the constitutional alterations of these factors in gastric juice by anti-secretagogues. METHODS: The mitogenic activity was evaluated by measuring [3H]-thymidine incorporation, and the EGF contribution was determined by using a specific anti-rat EGF antibody. An H2-receptor antagonist (IT-066) and a proton pump inhibitor (omeprazole) were used to determine whether these drugs alter the relative composition of active mitogens in gastric juice. RESULTS: Normal gastric juice significantly increased DNA synthesis. This activity was suppressed by antibody (87-88%). Both drugs increased EGF concentrations and activity dose-dependently IT-066 specifically increased total amount and activity of EGF. Approximately 50% of this activity was reduced by boiling or antibody. CONCLUSION: The major mitogenic activity of normal rat gastric juice depends on EGF, and antisecretory drugs enhance the mitogenic activity by preserving and including intraluminal mitogens than EGF.

Animals↗

Pathology and cellular kinetics of gallbladder with an anomalous junction of the pancreaticobiliary duct.

OBJECTIVES: Anomalous junction of the pancreaticobiliary duct (AJPBD) is thought to be an important risk factor for gallbladder carcinoma in Japan. In this report, we examine histopathology and cellular kinetics of gallbladder mucosae of patients with AJPBD and the possible risk of gallbladder carcinoma. METHODS: We examined 62 gallbladders from patients with AJPBD (group A), 16 gallbladder carcinomas from patients with AJPBD (group B), 60 gallbladder carcinomas from patients without AJPBD (group C), and six normal gallbladders from patients without AJPBD (group D). Histopathology, mucosal heights, and proliferative cell nuclear antigen-labeling index were obtained from routinely processed tissue specimens. RESULTS: The incidence of hyperplastic changes in group A and in the noncancerous regions (NCRs) of group B was greater than in the NCRs of group C (p < 0.05). The incidence of dysplastic changes in the NCRs of group B was greater than in the NCRs of group C (p < 0.05). The mucosal heights in group A and in the NCRs of group B were higher than in the NCRs of group C (p < 0.05). A high proliferative cell nuclear antigen-labeling index was observed in group A and in the NCRs of group B, where hyperplastic changes were frequently observed. CONCLUSIONS: These results suggest that a sequence of hyperplastic changes with a corresponding increase in cellular kinetics with progression through dysplasia to carcinoma may be important in carcinogenesis in gallbladders of patients with AJPBD. AJPBD itself may be a possible risk for gallbladder carcinoma.

Adolescent↗

[Development of simple on-line [oxygen-15]water infuser].

A [15O]water production and infusion system was newly developed for blood flow study with positron emission tomography. The system utilizes a electrostatic cooling unit to liquify [15O]vapor in a coiled plastic tube. Labeled [15O]water is collected into an infusion syringe by a wash of the trapping tube with saline. The system is simple and efficient; the recovery rate of [15O]water is over 90% at 10 degrees C of cooling temperature.

Cerebrovascular Circulation↗

[Characteristics and management of patients with lung cancer and idiopathic interstitial pneumonia].

Among 102 patients with idiopathic interstitial pneumonia (IIP), 22 with lung cancer who were treated from 1981 to 1994 were studied retrospectively. As controls, 248 patients with lung cancer only who were treated from 1991 to 1992 were also studied. Lung cancer developed in 6 of 85 patients after IIP was diagnosed (7.1%). The time from the onset of IIP to the onset of lung cancer was 7.7 years. In 17 patients both IIP and lung cancer were present on admission. In general, patients with IIP and lung cancer were heavy smokers. In patients with IIP and lung cancer, %VC was higher than in those with IIP alone, and 20 cancers (90.0%) were in peripheral lung fields. Seventeen patients received anticancer chemotherapy, irradiation, or both. Five patients (29.4%) died of respiratory failure due to progression of pneumonitis after the therapy. The prognosis for patients with IIP and lung cancer was very poor.

Aged↗

[Optimum dose study of cefozopran in the pediatric field].

Cefozopran (SCE-2787, CZOP) was administered to patients with pediatric infections three to four times daily by intravenous injection or 30-minute intravenous drip infusion, and investigations were made in individual cases, on relationships among doses, pharmacokinetics, effects on pathogenic bacteria and MIC against them, and clinical effects. The following results on optimal doses of CZOP were obtained. 1. Clinical cases in which CZOP was administered at a dose of 10 mg (potency)/kg The subjects were 7 patients including 4 patients with pneumonia. Severities of the diseases were severe in one of the patients with pneumonia, and moderate in the other patients. The MIC against pathogenic bacteria (4 strains) isolated from these cases ranged from 0.2 to 1.56 micrograms/ml. The serum concentrations were in a range between 1.4 and 7.6 micrograms/ml at 4 hours after administration. In some cases, the serum concentrations were lower than the MICs, though slightly. In the clinical evaluation, CZOP was excellent in 3 cases, good in 2 cases and fair in 1 case. The evaluation was impossible in 1 case. The efficacy rate was 83.3% (5/6). In bacteriological evaluation, 3 out of the 4 strains disappeared. Adverse reactions and abnormal laboratory test values were not observed. 2. Cases in which CZOP was administered at a dose of 20 mg (potency)/kg The subjects were 5 patients including 2 with pneumonia, and severities were severe in one of the patients with pneumonia, and moderate in the other patients. The MICs against the pathogenic bacteria (3 strains) isolated from these cases ranged from 0.1 to 1.56 micrograms/ml. While, serum concentrations at 4 hours after administration were in a range between 3.0 and 7.7 micrograms/ml sufficiently exceeding the MICs. In the clinical evaluation, CZOP was excellent in 1 case and good in four cases, with an efficacy rate of 100% (5/5). In the bacteriological evaluation, all the 3 strains disappeared. No adverse reactions were observed, but an abnormal laboratory test value showing eosinophilia was noted in one case. 3. Cases in which CZOP was administered at a dose of 40 mg (potency)/kg The subjects were 5 patients including 3 with pneumonia. The severity was moderate in 2 of the pneumonia patients, and severe in the other three cases. The MICs against the pathogenic bacteria (4 strains) isolated from these cases were in a range between 0.1 and 0.78 micrograms/ml. The serum concentrations at 4 hours after administration ranged from 6.5 to 21.9 micrograms/ml, sufficiently exceeding the MICs. In the clinical evaluation, CZOP was excellent in 4 cases and good in 1 case, with an efficacy rate of 100% (5/5). The efficacy rate in the bacteriological evaluation was also 100%. As adverse reaction, red urine was observed in one case. Eosinophlia was noted in one case in the laboratory tests. When CZOP was administered to patients with pediatric infections at a dose of 10 mg (potency)/kg, the clinical effect of the drug was insufficient in a case in which serum concentration of CZOP at 4 hours after administration was lower than the MICs against the pathogenic bacteria. When CZOP was administered at a dose of 20 mg (potency)/kg, sufficient concentrations were obtained, and the drug efficacies were found to be excellent or good in all cases. Therefore, the effective dose normally used is considered to be 20 mg (potency)/kg. When CZOP was administered at a dose of 40 mg (potency)/kg, the drug was found to be excellent or good in all of the cases although the severities were high in more than half of the cases tested. In addition, the rate of excellent efficacies was 80% (4/5). Furthermore, no severe adverse reactions were observed. It was, therefore, confirmed that CZOP should be administered at a dose of 40 mg (potency)/kg in severe or intractable cases.

Bacterial Infections↗

Contribution of the glycolytic pathway to enzymatic metmyoglobin reduction in myocytes.

The metmyoglobin (oxidized form of myoglobin) reducing enzyme system was examined in rat myocytes. An inhibitor of the glycolytic pathway (2-deoxy-D-glucose) inhibited the reduction of metmyoglobin in myocytes. An inhibitor of the citric acid cycle (malonic acid), did not inhibit this reaction. From the results of this study along with those of our previous work, we proposed that the glycolytic pathway may have a significant role in the enzymatic metmyoglobin reduction, presumably by its supply of cytoplasmic NADH for the NADH-cytochrome b5 reductase system, in muscle.

Animals↗

[Efficacy of implantable injection port for advanced breast cancer patients].

After breast cancer surgery, it is important to avoid drawing blood sample or injecting chemotherapeutic agents from the involved arm, because severe lymphedema and infection sometimes occurs. Adriamycin, one of the most effective drugs for breast cancer, frequently causes peripheral thrombophlebitis. Therefore, it is often difficult for advanced breast cancer patients to secure IV line and to finish the entire course of chemotherapy. For these reasons, an implantable injection port was applied in 26 breast cancer patients. The status of these patients was metastatic (9 patients), locally advanced (7 patients) and bilateral (10 patients). The average dwell time was 535.8 days with a range of 35 to 1,524 days. The complication events occurred at 0.047/100 catheter days. The results of this study indicate that the implantable injection port provides safe and reliable central venous access and improves the QOL of advanced breast cancer patients.

Adult↗

PET study of cerebral glucose metabolism and fluorodopa uptake in patients with corticobasal degeneration.

We measured cerebral glucose utilization and fluorodopa metabolism in the brain of patients with corticobasal degeneration using position emission tomography. The clinical pictures are distinctive, comprising features referable to both cerebral cortical and basal ganglionic dysfunctions. Brain images of glucose metabolism can demonstrate specific abnormalities with a marked asymmetry in the parietal cortex (the primary motor and sensory cortex and the lateral parietal cortex), the thalamus, the caudate nucleus and the putamen of the dominantly affected hemisphere related to clinical symptoms in six patients. [18F]dopa uptake also reduced in an asymmetric pattern, both the caudate nucleus and the putamen in four patients. This unique combination study measuring both cerebral glucose utilization and fluorodopa metabolism in the nigrostriatal system can provide efficient information about the dysfunctions which are correlated with individual clinical symptoms.

Aged↗

[Associated complication of biliary atresia: cystic dilatation of intrahepatic biliary system].

Cystic dilatation of intrahepatic biliary system (CDIB) was observed on 10 postoperative patients with biliary atresia (BA). Fever, jaundice and alcoholic stool were found when CDIB was diagnosed with ultrasonography and computed tomography assertained by cholangiography. CDIB was divided into three groups by the shape of intrahepatic biliary system. They were group A (n = 3); solitary non-communicating cyst, group B (n = 1); solitary communicating cyst and group C (n = 6); multi-cystic dilatation. Treatments of CDIB were percutaneous transhepatic bile drainage (PTBD) and reanastomosis of hepatic portoenterostomy. All of our patients of group A and B were doing well after PTBD in two and re-do Kasai operation in two. However, out of 6 patients of group C, two died without any treatments, three were transplanted liver from their parents and the rest one is still in the hospital and PTBD is continued. Outcome of CDIB is good in group A and B, and poor in group C.

Adolescent↗