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Biomedical subjects

K Ishida

Publications and source records attributed to K Ishida.

At least 487 records · Page 27Linked to original sources

[Experimental study of the 6-day subrenal capsule assay by cyclophosphamide pretreatment].

For the purpose to suppress the host immune reaction in subrenal capsule assay (SRCA) using normal immunocompetent mice, the effects of cyclophosphamide (CPM) pre-treatment (CPM 180 mg/kg day-1 s.c.) were compared with cyclosporine A (CSA) treatment (CSA 60 mg/kg s.c. daily). CPM and CSA suppressed host reaction until day 6 and day 12, respectively. However, in the histological evaluation of day 6 tumor, there was no difference between two groups. Mouse serum levels of CPM were measured by a bioassay as indicated by the cytotoxicity against P388 cells, to evaluate its residual activity against implanted tumor. No cytotoxicity was observed in the serum of 36 hr. after CPM injection. The antitumor activities of several chemotherapeutic agents against serially transplanted human esophageal cancer xenograft (IMEs-1) in untreated control group and CPM pre-treated group of SRCA were compared with the subcutaneous transplantation assay in nude mice. In all agents, the drug activities in CPM pre-treated group were similar to that in nude mice assay system. The increase of toxicity in CPM pre-treated group was very light. The immunosuppressive activity of CPM were also tested in 14 clinical samples. CPM suppressed the host reaction satisfactorily in all samples. These results suggest the usefulness of CPM pretreatment for suppressing the host reaction in SRCA.

Animals↗

[Clinical significance of serum levels of SCC antigen in patients with esophageal squamous cell carcinoma].

The levels of squamous cell carcinoma-related antigen (SCC) in sera of 71 patients with esophageal squamous cell carcinoma, 7 patients with benign esophageal diseases, 11 gastric cancer patients and 15 normal volunteers were studied in order to evaluate its clinical significance as a tumor marker. In the patients with esophageal carcinoma, immunosuppressive acidic protein (IAP) and carcinoembryonic antigen (CEA) were also measured simultaneously. In the normal volunteers, patients with benign esophageal diseases and gastric cancer patients, the SCC levels were negative except for only one patient. However, in patients with carcinoma of the esophagus 37 out of 71 were positive, the positivity rate being 52.1%. Comparison among SCC, IAP and CEA showed that the positivity rates for SCC and IAP increased with progression of the disease. In contrast, CEA levels did not correspond to clinical stage except in several patients with non-resectable and recurrent disease. With regard to the changes in serum levels of SCC, IAP and CEA before and after surgery and radio-chemotherapy. SCC was the most sensitive marker of the three, and responded well to the effects of therapy. SCC was thus considered to be a useful marker for monitoring esophageal cancer patients.

Aged↗

Short-term changes in levels of cyclic AMP, adenylate cyclase, and phosphodiesterase during the initiation of sperm motility in rainbow trout.

In order to clarify the role of the system that generates and degrades cyclic AMP during the initiation of motility of trout sperm, short-term changes in levels of intraspermatozoal cyclic AMP, adenylate cyclase, and phosphodiesterase were measured. Levels of cyclic AMP and the activity of adenylate cyclase increased and reached a maximum level 1 sec after transfer of sperm to K+-free medium, where they became motile, and then decreased rapidly. However, there were no changes in either parameter in sperm which remained immotile in K+-rich medium. In addition, an increase in the activity of phosphodiesterase was observed 4 sec later than the increase in levels of cyclic AMP and adenylate cyclase. These findings suggest that a very rapid change in the level of intracellular cyclic AMP occurs within 1 sec, at the moment of spawning, by the activation of adenylate cyclase and phosphodiesterase, and regulates the initiation of trout sperm motility.

Adenylyl Cyclases↗

Effects of oestrogen and anti-oestrogen on the cells of the endosteal surface of male Japanese quail.

1. The endosteal cellular response occurring in the early stages of medullary bone formation was histologically examined in the femurs of male Japanese quail treated with oestrogen and antioestrogen. 2. The numbers of endosteal cells decreased, and preosteoblasts and osteoblasts increased, on the endosteal surface following oestrogen treatment. 3. After oestrogen and anti-oestrogen treatment the numbers of preosteoblasts and osteoblasts on the endosteal surface did not increase. However, endosteal cells slowly decreased in number and osteoclasts increased. 4. This study demonstrates that differentiation of osteoblasts is induced by oestrogen stimulation and suggests that osteoclasts occur by oestrogen inhibition on the endosteal surface.

Animals↗

Effect of amino acid supplementation to low protein diet on brain and plasma levels of tryptophan and brain 5-hydroxyindoles in rats.

The contribution of amino acid transport across the blood-brain barrier toward the concentration of brain 5-hydroxyindoles [serotonin and 5-hydroxyindole acetic acid (5HIAA)] was investigated. Several amino acids were individually supplemented to a 5% whole egg protein diet. Close correlation between serum tryptophan, brain tryptophan and 5-hydroxyindoles were observed regardless of diet fed. When a large neutral amino acid (LNAA such as methionine, threonine, leucine or phenylalanine) was added to the control diet, brain 5-hydroxyindole concentration was lower than when the control diet was fed; however, when tryptophan was added, brain 5-hydroxyindole concentration was significantly higher. Lysine supplementation did not affect brain 5-hydroxyindole concentration. Leucine supplementation caused a lower tyrosine concentration in hypothalamus than the control diet, but phenylalanine supplementation caused higher hypothalamus level of tyrosine. There was no correlation between tyrosine and norepinephrine concentrations in hypothalamus (norepinephrine turnover might also be changed by the nutritional state). These observations indicate that the supplementation of an amino acid at two- or fourfold of the requirement to a low protein diet can generate major changes in the concentrations of neurotransmitters in rats.

Amino Acids↗

Immunohistochemical demonstration of prostaglandin E-2 in preimplantation mouse embryos.

An antiserum to prostaglandin (PG) E-2 and indirect immunofluorescence were used to demonstrate immunohistochemically the presence of PGE-2 in preimplantation mouse embryos. Fluorescence was observed in the cytoplasm of unfertilized 1-cell embryos to the blastocyst stage. The strongest fluorescence was detected at the 8-cell and morula stages. In embryos cultured from the 2-cell stage on, the fluorescence was observed in the cytoplasm of 4-cell embryos to the blastocyst stage. No differences were observed in the intensity and the distribution of the fluorescence between embryos in vivo and those in vitro. However, when blastocysts were cultured in a medium containing 100 microM-indomethacin, the fluorescence was diminished markedly. We therefore suggest that preimplanted mouse embryos contain PGE-2 during their early developmental stages and that the embryos synthesize the PGE-2.

Animals↗

[Analysis of the chemosensitivity test by subrenal capsule assay].

The antitumor activity of several chemotherapeutic agents against a total of 30 clinical samples obtained from 30 human tumors from the esophagus (12), stomach (10), colorectum (6) and lung (2), were tested by subrenal capsule assay (SRCA) using normal immuno-competent BDF, mice. The antitumor activity was evaluated by changes in both tumor size (delta TS method) and tumor growth inhibition rate (TGIR method). Among the 30 tumors, 15 were also tested by human tumor clonogenic assay (HTCA) and the results obtained in the two assays were compared. In the SRCA, adequate growth of the tumor in the control group for evaluation of the response of the treated group was obtained from 27 out of 30 tumors (90%). With activity criteria set at delta TS less than or equal to -1.0 dmm and TGIR greater than or equal to 50%, 41% of the drugs tested were active in delta TS while 27% were active in TGIR. When relationships between antitumor activities evaluated by delta TS and TGIR was compared, both activities were well correlated (r = -0.64). Correlations between tumor responses in the HTCA and in the SRCA were tested in 6 tumors treated with 20 drugs. The overall accuracy was 60% by the TGIR method and 70% by the delta TS method, respectively.

Animals↗

Effect of nicorandil on exercise performance in patients with effort angina: a multicenter trial using a treadmill exercise test.

The effects of a single oral dose (20 mg) of a new vasodilator, nicorandil, on exercise performance were assessed in 29 patients with stable effort angina using a symptom-limited treadmill exercise test. A single-blind, placebo-controlled, randomized, crossover design was employed. Compared with placebo, 20 mg of nicorandil significantly increased maximal exercise duration and time to 1 mm of ST-segment depression at 1, 3, and 6 h after administration. Systolic blood pressure was reduced both at rest and during exercise. Heart rate increase during exercise did not differ significantly compared with control, though resting heart rate was increased. The maximal pressure-rate product at peak exercise was increased in association with increased exercise time in about half of the patients, while it was unchanged or decreased in the others. It was suggested that nicorandil may act by either reducing myocardial oxygen demand and/or increasing myocardial oxygen supply.

Adult↗

[Experimental study of intralymphatic chemotherapy in rabbits].

In order to examine the clinical usefulness of intralymphatic chemotherapy and the regimen of the appropriate anticancer drug for this route, we measured serum and tissue drug levels following intralymphatic administration of Futraful (FT) or Neocarzinostatin (NCS) in rabbits. The results were as follows: When a low-molecular-weight drug such as FT was administered into the lymphatic vessels, most of the drug flowed into the systemic circulation through the thoracic duct, but some leaked from the lymphatic vessels and flowed into the portal vein via the intestine. In the case of a high-molecular-weight drug such as NCS, there was a tendency for it to remain in the lymph nodes. It therefore seems that a drug of high molecular weight is most suitable for use in intralymphatic administration.

Animals↗