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Biomedical subjects

K Iwata

Publications and source records attributed to K Iwata.

At least 325 records · Page 18Linked to original sources
PubMed1989

[Gastric acid secretions and serum gastrin levels in patients with mucosal and submucosal gastric cancers].

Gastric acid secretions and serum gastrin levels have been examined in 128 patients with early gastric cancer and in 98 gastric ulcer patients. Gastric cancer patients were found to have lower acid secretions than did gastric ulcer patients, and those with elevated types of a differentiated adenocarcinoma had lower acid secretions than did those with depressed types of an undifferentiated adenocarcinoma. Gastric acid secretions in patients with both a gastric ulcer and cancer were found to decrease with aging. However, the serum gastrin levels were found to be decreased in patients with a gastric ulcer and to be increased in patients with a gastric cancer. Incidences of a differentiated adenocarcinoma increased with aging. From these observations, it has been speculated that the carcinogenesis of a differentiated adenocarcinoma may be related to increasing endogenous gastrin levels and decreasing gastric acid secretions. These results suggest that a continuous check of the serum gastrin levels might be a good marker for cancer detection and that gastrin antibodies might be useful for treatment.

Adenocarcinoma↗
PubMed1989

[Distribution of pulsed intra arterial infusion chemotherapy in hepatic carcinomas].

Evaluation of "Gianturco-Wallace chemotherapy pulser," which was developed to produce a more homogeneous drug distribution of the tumors in intra-arterial infusion chemotherapy, was assessed by comparative study of pulsed and nonpulsed arterial radionuclide infusion using Tc-99m pertechnetate for 18 cases of hepatic carcinomas (11 cases of hepatocellular carcinomas and 7 cases of metastatic hepatic carcinomas). Tc-99m pertechnetate, 740 MBq (20 mCi) diluted with saline (30 mL) was infused with or without pulse through the catheter into the hepatic artery at a rate of 1mL per minute. The intrahepatic dynamic radionuclide distribution was analyzed by the time activity curves of ROIs in the tumor and nontumor areas. Pulsed infusion interrupted laminar flow and produced more homogeneous radionuclide distribution in the liver, and combination of pulsed and nonpulsed infusion also produced better radionuclide distribution in the areas of the tumors. This method using Tc-99m pertechnetate was very useful as a simulation to determine the dynamic drug distribution of the tumor and non-tumor region in intraarterial infusion methods.

Antineoplastic Agents↗
PubMed1989

[A case of advanced bladder cancer successfully treated with intraarterial chemotherapy].

A 79-year-old Japanese male came to our hospital with complaints of protraction and macroscopic total hematuria. The medical imaging methods revealed a large papillary tumor in the left lateral wall of the bladder with the staging of T3N0M0. The pathological diagnosis was transitional cell carcinoma, G3. He received intraarterial chemotherapy with CDDP, ADM and MTX, which was called IA-MAC regimen. After two IA-MAC, no medical imaging method could reveal the tumor. The biopsied specimen, which was taken using the transurethral resection of the bladder mucosa, demonstrated no malignant cells. The new chemotherapeutic regimen "IA-MAC" is useful for the treatment of localized advanced bladder cancer in clinical use and enables one to preserve the organ.

Aged↗
PubMed1989

[Optic disc measurements with computerized image analysis in experimental chronic glaucoma].

We quantitatively analyzed morphological changes of the optic disc of ten Japanese monkey eyes exposed to sustained intraocular pressure (IOP) elevation by repeated argon laser application to the trabecular meshwork. Using a computerized image analyzer (Topcon IMAGEnet), we measure the cup-disc ratio (CDR), disc area (DA), cup volume/disc area (CV/DA), and rim area/disc area (RA/DA). The duration of IOP elevation was 48.4 +/- 0.8 (mean +/- SD) weeks, and the mean IOP during the experiment was 26.3 +/- 2.6 mmHg [the mean IOP during the experiment/pre-treatment IOP was 2.05 +/- 0.55 (IOP ratio)]. In advanced glaucomatous eyes (the duration of IOP elevation of approximately one year), comparing pretreatment, the CV/DA increased 4.96 times, the vertical CDR increased 1.78 times, the horizontal CDR increased 1.69 times, the DA increased 1.42 times, and the RA/DA decreased 0.54 times. A significant positive correlation was found between the IOP ratio and, both the vertical CDR (gamma = 0.65) and the CV/DA (gamma = 0.68). These results suggested that the development of glaucomatous optic disc cupping correlated with the degree of IOP elevation in monkey eyes. Using this computer image analyser, the longitudinal quantitative follow-up of disc changes of experimental glaucoma may be useful for understanding the mode of human glaucomatous optic nerve damage.

Animals↗
PubMed1989

[Extracellular matrix of the human retrobulbar optic nerve].

The presence and distribution of laminin, fibronectin and type I through V collagens were determined in the human retrobulbar optic nerve using a immunohistochemical method, the biotin-streptavidin (B-SA) system. Type I and type III collagens, which were interstitial collagens, were detected diffusely within pial septa, pia mater, arachnoid membrane, dura mater and adventitia around the central retinal artery and vein. Type IV collagen and laminin, which were basement membrane materials, were localized linearly along the borders between optic nerve fascicles and pial septa, adventitia, pia mater. Also They were also stained in all vascular walls and the arachnoid membrane. Type V collagen and fibronectin were detected both in the interstitial connective tissues, diffusely, and in the basement membranes, linearly. Fibronectin was stained more intensively in the basement membranes than type V collagen.

Collagen↗
PubMed1989

[Dopamine infusion test as a gastric secretion test].

The secretion of gastric acid in the peptic ulcer patients were examined by the dopamine infusion test (DIT). Production of gastric acid was investigated when the patients were treated by 30-minute dopamine infusion of 2 micrograms/kg/min. According to the difference of production of gastric acid, 132 patients were categorized into three groups: 59 Cata-responders, 28 Ana-responders and 45 Non-responders. Cata-responders were the patients whose production was less than 0.2mEq/30 min, Ana-responders, greater than 0.2mEq/30 min and Non-responder less than or equal to 0.2mEq/30 min. Cata- and Ana-responders showed higher gastric acid secretion preoperatively, and higher gastric acid reduction rate after selective proximal vagotomy (SPV) than Non-responder. Cata-responder showed decreased acid output preoperatively and unchanged after SPV with DIT. Ana-responder showed increased acid output preoperatively and decreased after SPV with DIT. Non-responder showed unchanged acid output preoperatively and decreased after SPV. Cata-responder may be depending more on vagus-mediated factor and parietal cell mass. Ana-responder may be depending more on vagus-mediated factor, parietal cell mass and dopaminergic factor. Non-responder may be depending more on gastrin cell mass and less cholinergic influence. From these findings dopamine receptor may exist in the stomach, and DIT seems to be useful in studying pathogenesis of the peptic ulcer and determining treatment for patients with peptic ulcer.

Adolescent↗
PubMed1989

[Variation of intraocular pressure by non-contact tonometry and cardiac pulse wave].

We performed successive IOP measurements with a noncontact tonometer (NCT) in twelve eyes of six normal volunteers to analyze the relationship between the variation of IOP and the cardiac cycle. For this study, we devised a special apparatus composed of an photoelectric plethysmograph, an electric cardiograph and a NCT. With this apparatus, non-contact tonometry was permitted only at the peak or trough of the cardiac pulse wave. At the peak or trough of the cardiac pulse wave, IOP showed a variation of 0.8 +/- 0.4 mmHg (mean +/- s.d.) which was thought to be caused mainly by respiration. Between the peak and trough of the cardiac pulse wave, we found a maximum difference in IOP of 3.8 +/- 1.0 mmHg and a mean difference of 1.9 +/- 0.8 mmHg, which seemed to be attributable to the cardiac cycle.

Adult↗
PubMed1989

[Tracheoesophageal anastomosis for intractable aspiration pneumonia].

Permanent tracheostomy and tracheoesophageal anastomosis were performed as a means of surgical intervention for the treatment of intractable aspiration pneumonia. Conventional method of tracheoesophageal anastomosis has entailed various problems. The improved technique by the authors utilized the special histological features of the situation and makes possible safe and reliable anastomosis. This technique retains the tracheal perichondrium to strengthen the anastomosed portion of the trachea, and can thus prevent suture insufficiency due to tension upon the anastomotic site.

Aged↗
PubMed1988

Expression of the insulinoma gene rig during liver regeneration and in primary cultured hepatocytes.

We have isolated a novel gene, rig (rat insulinoma gene) from rat insulinomas. In the present study, rig was found to be expressed in rat regenerating liver and in primary cultured rat hepatocytes. The level of rig mRNA was increased at the proliferative phase of liver regeneration. In synchronously cultured hepatocytes, the rig mRNA level was elevated at the G1 phase of the cell cycle and the rig-protein was accumulated in the nuclei during the S phase. These results indicated that rig could be involved in a more general way in growth or cell replication.

Adenoma, Islet Cell↗
PubMed1988

Urinary trehalase activity as an indicator of kidney injury due to environmental cadmium exposure.

One hundred and seventy-eight subjects, patients with Itai-itai disease and their family members, aged 12-87 years living in a cadmium (Cd)-polluted area in the Jinzu River basin (Cd-exposed group) and 176 controls (control group) were examined. In the Cd-exposed group urinary trehalase increased with increasing age, urinary beta 2-microglobulin (beta 2-m) and retinol-binding protein. Although urinary cadmium was higher in the Cd-exposed group, no particular correlation was found between urinary trehalase and urinary cadmium. Seventeen men and 11 women showed raised urinary trehalase activities despite normal values of urinary beta 2-m (less than 300 micrograms/g.creatinine), suggesting that urinary trehalase increases earlier than urinary beta 2-m. In 19 patients with Itai-itai disease included in the Cd-exposed group, urinary trehalase decreased with decreasing reciprocal of serum creatinine, suggesting that urinary trehalase decreases in the most advanced cases of chronic cadmium nephropathy due to reduced tubular cell mass.

Adolescent↗
PubMed1988

Interhemispheric subdural haematoma complicated by intracerebral haematoma: case report.

The authors describe a case of interhemispheric subdural haematoma which was followed by an ipsilateral intracerebral haematoma after an interval of about a half day. The intracerebral haematoma is considered to be the consequence of a haematoma induced thrombosis of cortical veins in connection with a bleeding diathesis due to previous anticoagulant therapy.

Cerebral Angiography↗
PubMed1988

The possible analgesic effect of soft-laser irradiation on heat nociceptors in the cat tongue.

These effects were studied by recording single-fibre discharges in the lingual nerve. A total of 11 heat nociceptors were tested and of these 60 per cent decreased their firing frequency following soft-laser (GaA1As semiconductor laser) irradiation for 1 min; firing frequency was decreased in all the nociceptors studied following irradiation for 3 to 10 min. The reduction in firing rate was similar between 5 and 10 min after irradiation suggesting the effect reached a plateau within this time. These findings suggest that soft-laser irradiation might have an analgesic effect on tongue pain.

Action Potentials↗
PubMed1988

Hyperthermic effects on DNA repair of UV-irradiated Dictyostelium discoideum.

DNA repair of a lower eukaryote, Dictyostelium discoideum, has been investigated through the analysis of heat effects on cell mortality and DNA repair of UV-irradiated amoeboid cells. In a wild-type strain (NC4), an increase in temperature immediately after UV irradiation resulted in an increase in cell mortality, though similar heat treatment before UV irradiation had no such effect. Similar results were obtained in another wild-type strain, HPS83. In NC4, heat treatment after UV irradiation did not inhibit the nicking of DNA strands during excision repair processes, but did inhibit the rejoining of the DNA strand breaks. Removal of thymine-containing pyrimidine dimers from DNA molecules was also depressed by heat treatment after UV irradiation. In contrast, heat treatment before UV irradiation had no effect on any stage of the nicking process, the excision of the dimers or the rejoining. On the other hand, a radiation-sensitive mutant (TW8) defective in an incision step of the excision repair process did not show an increase in cell mortality in response to heat treatment administered either before or after UV irradiation. Though the optimum temperature for cell growth of the amoebae was 23 degrees C, the critical temperature for effective enhancement of cell killing was ca. 30 degrees C. Hence we assume that the excision repair of UV-damaged DNA is selectively sensitive to heat treatment.

Centrifugation, Density Gradient↗