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Biomedical subjects

M Itoh

Publications and source records attributed to M Itoh.

At least 901 records · Page 50Linked to original sources
PubMed1990

N-[18F]fluoroacetyl-D-glucosamine: a potential agent for cancer diagnosis.

Positron labeled substrates such as sugars, amino acids, and nucleosides have been investigated for the in-vivo evaluation of biochemical processes in cancerous tissue. Hexosamines are obligatory structural components of many biologically important macromolecules, including membrane glycoproteins and mucopolysaccharide. We evaluated a new synthesized pharmaceutical, N-[18F]fluoroacetyl-D-glucosamine (18F-FAG), which is a structural analog of N-acetyl-D-glucosamine. C3H/HeMsNRS mice bearing spontaneous hepatomas were used for the tissue distribution study. At 60 min after injection, high uptakes were found in tumor (5.16, mean value of %dose/g), liver (3.71), and kidney (3.27). The tumor uptake of 18F-FAG showed the highest value in all tissue. In the PET study, VX-2 carcinoma of the rabbit was clearly visualized. Our preliminary results suggest that 18F-FAG has potential as a new agent for tumor imaging.

Acetylglucosamine↗
PubMed1990

[Role of PAF for the formation of gastric mucosal injury induced by ischemia-reinfusion in the rat].

Oxyradicals of neutrophils are supposed to play a role in the formation of gastric mucosal injury induced by ischemia-reinfusion (I-R). Recently, platelet-activating factor (PAF) is suggested to be involved in the I-R injury as one of chemical mediators since this substance may be produced in hypoxic tissue, stimulating oxyradical generation of neutrophils. In the present study, using CV-3988, a PAF antagonist, the severity of gastric mucosal damage and chemiluminescence (CL) activity of neutrophils of circulating blood were measured to evaluate the role of PAF in the I-R injury. SD rats fasted overnight were anesthetized and instilled 0.1N HCl into the stomach. Rats were then subjected to reduction of blood pressure to 20-30 mmHg for 20 min by bleeding followed by reinfusion of shed blood for 20 min. Two groups of rats each received 10 mg/kg CV-3988 (PAF-A grup) or saline (I-R group) i.v. 5 min prior to bleeding. After killing rats, the area of gross gastric lesions and the index of histologic damage were assessed. In separate PAF-A and I-R groups of rats, and control rats received saline i.v. and no hypotension, blood samples were collected from the portal vein and the abdominal aorta 45 min after acid instillation. Luminol-dependent CL stimulated by PMA of blood samples was measured using the photometer Monolight 401. CL activity was expressed as [peak CL/neutrophils number].(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

[Evaluation of SOD activity in gastric mucosa of hemorrhagic shock rats].

UNLABELLED: Superoxide dismutase (SOD) exogenously administered has been documented to protect gastric mucosa against ischemia-reinfusion injury by scavenging oxygen radicals. However, the changes in levels of endogenous SOD in ischemic gastric mucosa are not known. To evaluate this, the present study was designed. METHODS: Fasted and anesthetized SD rats were given 0.1 N HCl i.g. and received the following procedures. Study 1: (1) Ischemia group--25 min after acid instillation, blood pressure was reduced to 20-30 mmHg for 20 min. (2) Ischemia-Reinfusion group--5 min after acid administration, rats received the same hypotension as above followed by reinfusion of shed blood for 20 min. (3) Control group-Rats were killed 45 min later without hypotension and reinfusion. Study 2: Three groups of rats treated with the same procedures as in Study 1 were given allopurinol (50 mg/kg/day) i.g. once daily for 2 days prior to the experiment. All rats were killed by exsanguination from the carotid artery to avoid as much as possible contamination of gastric mucosal samples with red blood cells rich in SOD. The supernatants of the corpus and antral mucosa homogenized were prepared for measuring their SOD activity using the nitrite method modified by Oyanagui. RESULTS: SOD activity in the gastric mucosa significantly increased in both the Ischemia (Ische.) and Ischemia-Reinfusion (I-R) groups compared to the control (Ische. vs. I-R vs. Cont'l: corpus-123.4 +/- 4.8 vs. 127.4 +/- 3.6 vs. 96.9 +/- 4.4 NU/Mg protein; antrum-71.6 +/- 2.8 vs. 81.4 +/- 6.8 vs. 62.1 +/- 3.1 NU/mg protein). No increase in SOD activity was observed in rats pretreated with allopurinol. CONCLUSION: SOD activity increases with oxyradicals generation in the rat stomach subjected to either hemorrhagic ischemia alone or hemorrhagic ischemia plus reinfusion. This also suggests that oxyradicals are generated even in the ischemic period.

Animals↗
PubMed1990

[Toxicity of cis-platinum loaded with lactic acid oligomer microspheres in mice].

We have evaluated the acute toxicity of an experimental new dosage form administered intraperitoneally in mice, consisting of cis-platinum loaded with lactic acid oligomer microspheres (CDDP-ms). The LD50 value of the CDDP-ms was 23.8 mg/kg, which amounted to 176% of the LD50 of the cis-platinum solution (13.5 mg/kg). Autopsy findings revealed no additional toxicity due to this dosage form.

Animals↗
PubMed1989

An enzyme immunoassay of slow moving protease (SMP) in human gastric mucosa.

A two-site enzyme immunoassay for slow moving protease (SMP) of human gastric mucosa has been developed. The detection limit of SMP was 50 pg/tube and the optimal assay range was 0.5 to 50 ng/tube. This assay system made it possible to measure a trace amount of gastric mucosal SMP in endoscopic biopsy-specimens. Mean gastric mucosal SMP contents of the antrum, the angles, and the distal and proximal corpuses were 4.5, 3.7, 2.6, and 2.5 micrograms/mg protein, respectively. The antral mucosa contained a larger amount of SMP than the gastric mucosa of other area. The present enzyme immunoassay system is sufficiently sensitive for the clinical study of SMP in gastrointestinal tract.

Electrophoresis, Polyacrylamide Gel↗
PubMed1989

Giant lymph node hyperplasia (Castleman's disease) with spontaneous production of high levels of B-cell differentiation factor activity.

A 13-year-old girl presented with general fatigue, back pain, anemia, hyperimmunoglobulinemia, and a mediastinal mass on chest radiograph. A mass was surgically removed, and its histologic examination determined the diagnosis of giant lymph node hyperplasia (Castleman's disease). With removal of the hyperplastic lymph node, the clinical symptoms soon disappeared and the abnormal laboratory findings were markedly improved within 1 month: serum IgG levels decreased from 4350 mg/dl to 1829 mg/dl. Immunostaining on the lymph node sections revealed polyclonal B-lymphocyte and T-lymphocyte populations. The patient's lymph node cells were cultured without any mitogenic stimulation, and the culture supernatants were assayed for their B-cell differentiation factor (BCDF) activity to induce IgG production by our Epstein-Barr virus-transformed cell line. The patient's lymph node cells produced high levels of BCDF activity: the supernatants could increase the IgG production from 140 ng/ml to 410 ng/ml when the values became from 140 ng/ml to 142 ng/ml or 148 ng/ml with those of the control lymph node cells. These results suggest that the hyperimmunoglobulinemia and its prompt improvement with removal of the hyperplastic lymph node may have been related to the spontaneous production of high levels of BCDF activity by the lymph node cells in the patient.

Adolescent↗
PubMed1989

Metabolic fate of L-[methyl-11C]methionine in human plasma.

The metabolites of L-[methyl-11C]methionine in the plasma of 8 patients with tumors were measured for 60 min after injection. In the plasma, after a rapid clearance, the total radioactivity remained constant, and protein-bound radioactivity increased rapidly. Non protein metabolites detected by HPLC as at least two components besides methionine, increased with time. Significant individual variations for the metabolism were observed. At 60 min after injection, 36.5% (range: 16%-72%) and 45.3% (range: 13%-74%) of the 11C was measured as methionine and labeled proteins, respectively.

Adolescent↗
PubMed1989

Microscopic intranasal decompression of the optic nerve.

We report our methods for using the surgical microscope to decompress the optic nerve intranasally and our results in five cases with optic nerve trauma, including a 7-year-old girl. Decompression seemed necessary in cases without canal fractures (four cases in the present report), since circular disturbances from edema may play a role in producing reversible visual impairments. The intranasal approach not only solved cosmetic problems associated with other techniques, but also provided better, less distorted views when compared with extranasal or transantral approaches. Microsurgery using a self-retaining retractor speculum resulted in improved visualization and reliable procedures during surgery. Since the operation does not impose a cosmetic or physical burden on patients, it can be done early when indicated to accelerate visual improvement following trauma.

Adolescent↗
PubMed1989

Postoperative sequelae of augmentation mammaplasty by injection method in Japan.

Postoperative sequelae of 696 cases following augmentation mammaplasty by the injection method have been studied. The most frequently used foreign material for injection was silicone. Paraffin had been previously used somewhat less frequently. Of the 696 cases studied, the most common complications were hardening, skin change, transformation, and pain. Of the total number of cases studied for removal of the foreign material, 244 were seen in university hospitals and 416 in private clinics. Reaugmentation was performed in many cases using both a flap technique and bag prostheses with no significant degree of incidence of complications following reaugmentation.

Breast↗
PubMed1989

Four tandem defective P elements associated with positive regulation of the Drosophila melanogaster glucose-6-phosphate dehydrogenase gene.

Three high-glucose-6-phosphate dehydrogenase (G6PD)-activity mutants (2512H, S44H, and 1FH) are characterized by two insertion sequences associated with the G6PD locus; one (Ins1; 3.5 kb long in 2512H and S44H and 2.9 kb long in 1FH) is present just 5' to exon I and consists of a KP' (the 32nd base of the KP was replaced by guanine), a core sequence and a KP, and the other is 4.2 kb long and resides within an intron. Southern blot analyses of revertants showing low G6PD activity suggested that the insertion sequence responsible for high G6PD activity may be the core sequence but not the flanking KP and KP' or the Ins2. DNA sequencing data of the clone carrying the core sequence of 2512H demonstrated that the core sequence is another type of defective P elements (core P). Interestingly, a protein(s) was found in the nuclear extract of Canton S embryos that specifically binds to the core P but not to the KP or various fragments of p pi 25.1. In addition, the mutant G6PD activity was found to be affected not only by the genotype, but also by cytoplasmic factors.

Animals↗
PubMed1989

A case of the pathogenesis of choledochocele in relation to dysfunction of the sphincter of Oddi.

A 47-year-old woman was admitted for evaluation of pain in the right upper quadrant of the abdomen. Seventeen years previously, she had undergone cholecystectomy for cholelithiasis. Endoscopic retrograde cholangiopancreatography (ERCP) showed a cystic dilatation of the terminal portion of the common bile duct (CBD) protruding into the duodenal lumen and delaying the drainage of contrast medium. In this patient the CBD and the pancreatic duct appeared to be unimportant in the formation of the cyst. Repeated changes in the radius of the cyst suggested dysfunction of the ampullary component of the sphincter of Oddi, with maintenance of normal function of the common duct component. The pathogenesis of the choledochocele in this patient is discussed in relation to dysfunction of the sphincter of Oddi. In addition, 2 criteria for the diagnosis of choledochocele by ERCP are proposed: [1] cystic dilatation of the terminal portion of the CBD protruding into the duodenal lumen, and [2] absence of the narrow segment of the CBD.

Ampulla of Vater↗
PubMed1989

Two toxins from the venom of Trimeresurus tokarensis.

1. Two toxins, Tokaratoxin-1 (TT-1) and Tokaratoxin-2 (TT-2), were isolated from the venom of Trimeresurus tokarensis using gel filtration on a Sephadex G-100 column, followed by chromatography on DEAE-Sephacel and carboxymethyl-cellulose. TT-1 possessed both hemorrhagic and proteolytic activities. However, TT-2 did not show hemorrhagic activity. 2. Homogeneity was established by the formation of a single band in acrylamide gel electrophoresis, isoelectric focusing and SDS-PAGE. 3. Molecular weights of TT-1 and TT-2 were 71,000 and 25,400, respectively. Although TT-2 is a basic protein, TT-1 is an acidic protein. 4. Biological activities of TT-1 and TT-2 were inhibited by EDTA, EGTA and o-phenanthroline, suggesting that the toxins are metalloproteins. Atomic absorption analyses indicated that TT-1 contains 2.79 mol Ca/mol protein and TT-2 contains 1.04 mol Ca/mol protein and 1.07 mol Zn/mol protein, respectively. 5. The two toxins degraded the A alpha and B beta chains of fibrinogen. 6. TT-1 induced necrosis in addition to its hemorrhagic activity while TT-2 induced necrosis only.

Amino Acid Sequence↗