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Biomedical subjects

K Kodama

Publications and source records attributed to K Kodama.

At least 649 records · Page 36Linked to original sources

Gastric- and intestinal-type properties of human gastric cancers transplanted into nude mice.

The gastric- and intestinal-type properties of 15 human gastric cancers, which were transplanted into nude mice, were studied biochemically and histologically. Enzyme activities were determined in the crude extracts of cancer tissues: pepsinogen isozymes as gastric marker enzymes; and sucrase, aminopeptidase (microsomal), and alkaline phosphatase as intestinal marker enzymes. By hematoxylin and eosin staining and paradoxical concanavalin A staining, gastric cancer tissues were classified into gastric type (pyloric gland cell type and surface mucous cell type) and intestinal type (goblet cell type and intestinal absorptive cell type). On the basis of their properties, human gastric cancers were classified into four types: (a) intestinal type; (b) gastric type; (c) intestinal plus gastric type; and (d) unclassified type, showing no gastric- or intestinal-type properties. Of six well-differentiated adenocarcinomas, four were of intestinal type, one of gastric type, and one of intestinal plus gastric type. All of the intestinal-type carcinomas showed sucrase activity. Of the three signet ring cell carcinomas, one was classified as a gastric type, one as an intestinal plus gastric type, and one as an unclassified type. Of the six poorly differentiated adenocarcinomas, five were of the intestinal type and one of the unclassified type. The present results clearly showed the appearance of intestinal-type properties in gastric cancer cells not only in so-called intestinal-type carcinomas, but also in diffuse-type carcinomas.

Adenocarcinoma↗

Dose response, wavelength dependence, and time course of ultraviolet radiation-induced unscheduled DNA synthesis in mouse skin in vivo.

A new method for autoradiographic measurement of unscheduled DNA synthesis (UDS) in the skin in vivo after treatment with ultraviolet light (UV) was developed. The skin of the back of ICR mice was shaved and exposed to short-wave UV (254 nm) or UVAB (sunlamp, 270 to 440 nm, predominant emission at 312 nm) at various doses. Immediately after irradiation, an isotonic aqueous solution of [methyl-3H]thymidine was injected s.c. into a portion of the skin clamped off with ring-shaped forceps. By this method, dose-dependent UDS was clearly demonstrated as silver grains on various types of cells in the skin in response to 254 nm UV or sunlamp UV. However, the energy values at the two wavelengths required to induce the same UDS level differed by 1 order of magnitude. These findings suggested that this system should be useful for quantitative analysis of UV-induced DNA repair in individual cells of the skin in vivo. By this method, the wavelength difference in transmissibility was studied. Autoradiographic results clearly showed that sunlamp UV could reach deeper sites in the skin than did 254 nm UV. A time course study indicated that UDS was almost complete by 48 hr after 254 nm UV but still persisted at 48 hr after sunlamp UV. These results, together with the differences in transmissibility, support higher tumorigenic activity of sunlamp UV than of 254 nm UV to experimental animals.

Animals↗

Validity of contrast hyperemia for clinical assessment of coronary flow reserve: the optimal dose of contrast medium and reproducibility of the technique.

The dose-response relation of contrast medium-induced hyperemic response in coronary blood flow (contrast hyperemia) was investigated to determine the optimal dose of contrast medium (CM, Urografin-76) for the assessment of coronary flow reserve in man. The great cardiac venous flow (GCVF) was determined with the continuous thermodilution method during the contrast hyperemia induced by the intracoronary injection of CM of three different doses, ie, 2, 4, and 6 ml/60 kg of body weight, into left coronary artery. Submaximal coronary vasodilation could be obtained by intracoronary injection of 4 ml of CM with minimal changes in systemic hemodynamics. The contrast hyperemia with this dose of CM was reproducible and also closely correlated with that obtained during pacing-induced angina. Thus, we conclude that the contrast hyperemic technique with intracoronary injection of 4 ml of Urografin-76 could be a reliable method to assess the coronary flow reserve.

Blood Circulation↗

Synergistic anti-tumor effect of mini-cells prepared from Salmonella typhimurium with mitomycin C in EL4-bearing mice.

A statistically significant increase in survival time was observed in EL4-bearing mice after a mini-cell inoculation. However, no case of survival for over 30 days was observed after an EL4 graft in mice treated with mini-cells alone. Fifty percent of the mice survived for 40 days after an EL4 transplantation when the mice were treated with both an IV injection of mini-cells and an SC injection of mitomycin C. The mini-cell injection restored the macrophage chemotaxis activity in EL4-bearing mice but did not restore the lymphocyte activities.

Animals↗

Transient collateral augmentation during coronary arterial spasm associated with ST-segment depression.

To examine the possible existence of collateral circulation during coronary artery spasm, we attempted to visualize the transient appearance of collateral vessels that could serve to salvage otherwise jeopardized ischemic areas. In three patients with vasospastic angina, total spastic obstruction of a major coronary artery was associated with transient collateral augmentation, which was supplied by the nonspastic artery during anginal period associated with ST-segment depression. These collateral vessels disappeared when the angina and ST changes resolved after nitroglycerin administration. These findings suggest that the collateral blood supply could transiently occur through preexisting vessels to perfuse the ischemic area during coronary artery spasm and that such collateral flow could have a role in preventing transmural myocardial ischemia, resulting in a lesser degree of ischemia associated with ST-segment depression.

Adult↗

Arteriographic features of angina pectoris associated with ST segment depression during coronary arterial spasm.

To examine the angiographic features of vasospastic angina associated with ST segment depression, we attempted to analyze the coronary arteriograms of 12 patients who exhibited ST segment depression during the ergonovine provocative test. Right and left coronary arteriograms were obtained successively within a short period when the ergonovine administration revealed ST segment depression. Eight out of 12 patients showed non-total spastic obstructions in one of the major coronary arteries. Among them, a collateral augmentation was found only in one patient. Two cases exhibited the well-developed collateral channels during non-anginal periods and in one case a collateral blood supply was reduced by the spasm occurred in the donating artery. In another one, the collateral circulation did not change during anginal period. Three out of 4 patients who showed total spastic obstructions demonstrated transiently augmented collateral circulation which was supplied by the non-spastic artery. These findings may indicate that ST segment depression during coronary artery spasm could attribute to a subendocardial ischemia caused by an incomplete occlusion of large coronary artery and transient reduction or augmentation of collateral blood flow.

Adult↗

Acute effects of intravenous trapidil on hemodynamics, coronary circulation and myocardial metabolism in man.

The acute effects of intravenous trapidil on hemodynamics, coronary circulation and myocardial metabolism were evaluated in 19 patients (Group I: 10 patients of chest pain syndrome; Group II: 9 patients of coronary heart disease). The heart rate increased (p less than 0.05) and aortic pressure decreased (p less than 0.01) during a 6-min study period. Pulmonary arterial end-diastolic pressure decreased slightly in both groups and cardiac output increased prominently in Group II. Myocardial oxygen consumption did not change significantly 3 and 6 min after trapidil injection. Coronary sinus flow increased slightly (statistically not significant) despite a decrease in aortic pressure, and thus, coronary vascular resistance decreased significantly in both groups. Coronary A-V O2 difference decreased 3 min after trapidil injection and no significant change in the lactate extraction ratio was observed. The diameter of the left main coronary artery increased by about 6% after an administration of trapidil. These results suggest that trapidil has the beneficial effect of coronary vasodilation and it increases cardiac output, despite a decrease in the preload, without a significant increase in myocardial oxygen consumption. The latter may be due to an afterload reduction effect of this drug.

Aged↗

Effects of hypertonic mannitol on renal function in open heart surgery.

An extracorporeal bypass was performed in mongrel dogs for 2 hours with or without hypertonic mannitol infusions. In animals given mannitol, the plasma osmolality was elevated maximally to 344 +/- 7.1 mOsm/L and the urine volume was maintained well during bypass. A hypertonic mannitol solution was effective in maintaining the CPAH during and after bypass, but was not effective in minimizing the reduction in Ccr. When the mean arterial pressure during bypass was kept at 60 mmHg, the carbon filling rates in glomeruli showed the favorable effects of mannitol upon renal function, but no effects were observed at a mean arterial pressure of 80 mmHg. In 11 patients who had undergone a bypass lasting more than 2 hrs with mannitol infusions, the plasma osmolality reflected the serum mannitol level and reached 320 +/- 11.0 mOsm/L at 150 min of bypass. The mean urine volume was 5.0 +/- 3.3 ml/min/M2 during the bypass, which was about 7 times as great as before the bypass. The Ccr increased during the first 30 min of the bypass, but it fell to about one half of the initial value after 90 min of the bypass. It was concluded that a hypertonic mannitol solution is effective in maintaining the RPF and urine volume during and after the bypass and that it also preserved the glomerular perfusion even at a low arterial pressure.

Acute Kidney Injury↗

Demonstration of a circulating autoantibody against a soluble eye-muscle antigen in Graves' ophthalmopathy.

Mouse monoclonal antibodies against antigens in human eye muscle, orbital connective tissue, and lacrimal tissue and guineapig harderian gland have been produced by means of the hybridisation technique. From 14 fusions, over 30 antibodies have been produced, of which 24 have been maintained and characterised for the present studies. All were IgG1. Most were organ-specific, but eye-muscle antibodies tended to cross-react with skeletal muscle, one eye-muscle antibody cross-reacted with thyroidal microsomes, and both lacrimal monoclonal antibodies reacted strongly with mucus-secreting cells in human small intestine. Only one of the antibodies fixed complement. Orbital monoclonal antibodies were used as probes to identify orbital antigens. Most antigens were in the cytosol fraction, but a few were demonstrated in cytoplasmic membranes. Circulating autoantibodies against a human-eye-muscle soluble antigen were detected in 17 of 23 patients with Graves' ophthalmopathy but in only 1 of 14 patients with Hashimoto's thyroiditis, in 2 of 11 patients with subacute thyroiditis, in no patient with Graves' hyperthyroidism without eye disease, and in none with multinodular goitre.

Adolescent↗

von Recklinghausen's disease and malignant changes in three patients.

Three Japanese patients with von Recklinghausen's disease and malignant changes were studied. The primary lesions of malignant changes were the chest wall in Case 1, the buttock in Case 2, and the neck in Case 3. After excision of the tumors, there were local recurrences in Cases 1 and 2. Distant metastases developed during treatment in these patients. One of the patients (Case 1) died 21 months after the initial diagnosis of malignancy. Multidisciplinary treatment was of some value in suppressing local recurrences and pulmonary metastases in Case 2. Pulmonary metastases were evident at the time of admission to our hospital in Case 3. Although the primary and metastatic tumors were removed, the patient died 8 months after the initial diagnosis of malignancy. We conclude that careful follow-up should be required in patients with von Recklinghausen's disease because of the possibility of malignant changes. When there is a suspicion of malignancy, an extended en-block excision must be performed.

Adolescent↗

Purine metabolic enzymes in lymphocytes. II. Adenosine deaminase and purine nucleoside phosphorylase activities in the immune response.

ICR mice were immunized with sheep red blood cells (sRBC). Both adenosine deaminase (ADA) and purine nucleoside phosphorylase (PNP) activities in spleen lymphocytes increased faster than the serum antibody titer and reached a peak one week after the immunization. ADA activity increased significantly in T lymphocytes but not in B lymphocytes collected from the spleens of the immunized mice. A statistically significant increase in PNP activity was found in both T and B lymphocytes from the spleens of the immunized mice. Spleen lymphocytes collected from ICR mice which had been immunized with mitomycin C-treated sarcoma 180 (S180) cells one week earlier showed cytotoxic activity against viable S180 cells. Both ADA and PNP activities in spleen lymphocytes of S180-immunized mice increased significantly, and both activities increased in T lymphocytes prepared from spleen of immunized mice. In contrast, an increase was found in PNP activity but not in ADA activity in B lymphocytes. These results suggest that an increase in both ADA and PNP activities may by necessary for the T-cell response in both humoral and cellular immune responses, and that an increase in PNP activity may be necessary for the B-cell response.

Adenosine Deaminase↗