Biomedical subjects

R Izumi

Publications and source records attributed to R Izumi.

At least 37 records · Page 2Linked to original sources

PubMed1998

[Evaluation of a new anti-cancer drug regimen for endometrial cancer].

BACKGROUND: The purpose of this study was to describe a new anti-cancer drug regimen for endometrial cancer. METHODS: The cytotoxicities of some anti-cancer drugs regimens against human endometrial cancer xenografted into nude mice (TEI, TET, TEU, TEN) have been studied. The activities of ADM, CDDP, CPM, CPT-11, TXL, CDDP + ADM, CDDP + CPM, CDDP + CPT-11, CDDP + TXL, CPT-11 + TXL were evaluated in comparison with a control group using saline. Three mice were used for each group, and when xenografted tumor reached 6 mm of its diameter, 1/5 LD50 of these drugs was administered into the periotoneal cavity mice once a week for three weeks. RESULTS: The effective regimens were CPT-11 + TXL, CDDP + CPT-11, CDDP + CPM, CDDP + TXL for the endometrial cancer. CONCLUSIONS: It is suggested that these new drugs regimens should be tested in clinical studies.

Animals↗

PubMed1998

[Evaluation of a new anti-cancer drug regimen for surface epithelial-stromal ovarian cancer].

BACKGROUND: The purpose of this study was to describe a new anti-cancer drug regimen for epithelial ovarian cancer. METHODS: The cytotoxicities of some anti-cancer drugs regimens against human epithelial ovarian cancer xenografted into nude mice (TOM, TOH, TON) have been studied. The activities of CDDP, CPT-11, TXL, CDDP + CPM, CDDP + CPT-11, CDDP + TXL, CPT-11 + CPM, CPT-11 + TXL, and TXL + CPM were evaluated comparing with a control group using saline. Three mice were used for each group, and when the xenografted tumor reached 6 mm in diameter, 1/5 LD50 of these drugs was administered into the peritoneal cavity of mice once a week for three weeks. RESULTS: The three most effective regimens were CPT-11 + TXL, CDDP + CPM, and CDDP + CPT-11 for epithelial ovarian cancer.

Adenoma↗

PubMed1998

[Early phase II trial of oral etoposide administered for 21 consecutive days in patients with cervical or ovarian cancer. ETP 21 Study Group--Cervical-Ovarian Cancer Group].

We conducted multi-site early phase II trial or oral etoposide administered for 21 consecutive days in patients with cervical or ovarian cancer in cooperation with 19 institutes. Fifty mg/body of oral etoposide was administered daily for 21 consecutive days. Cycles were repeated every 28 days. In cervical cancer, 24 patients were enrolled and 17 of them were evaluated. The overall response rate including CR and PR was 23.5% (4/17). In ovarian cancer, 18 patients out of 21 enrolled were evaluated. The overall response rate was 16.7% (3/18). The primary toxicity observed was myelosuppression such as leukopenia, neutropenia, hemoglobin decrease and thrombocytopenia. Other adverse effects were anorexia, nausea, vomitting, fatigue, alopecia and stomatitis. From these results we concluded that oral etoposide administered for 21 consecutive days was effective against cervical cancer.

Administration, Oral↗

PubMed1998

[Late phase II trial of oral etoposide administered for 21 consecutive days in patients with cervical cancer. ETP 21 Study Group--Cervical Cancer Group].

We conducted a multi-site late phase II trial of oral etoposide administered for 21 consecutive days in patients with cervical cancer in cooperation with 32 institutes. Fifty mg/body of oral etoposide was administered daily for 21 consecutive days. Treatment cycles were to be repeated at 4- to 5-week intervals. Eighty patients were enrolled and 70 patients were evaluated. The overall response rate (95% CI), including one complete response patient and 18 partial response patients, was 27.1% (19/70). The most commonly observed toxicity was myelosuppression such as leukopenia, neutropenia, hemoglobin decrease and thrombocytopenia. Other adverse effects were gastrointestinal toxicities such as anorexia, nausea, stomatitis and vomiting, as well as fatigue and alopecia. These adverse effects were well tolerated and controlled with medications. From these results we concluded oral etoposide administered for 21 consecutive days was an effective drug against cervical cancer.

Adenocarcinoma↗

PubMed1997

Odontogenic myxofibroma arising from the periodontal ligament in the maxillary molar region.

A rare case of odontogenic myxofibroma, which arose from the periodontal ligament and expanded into the oral cavity resulting in an epulis-like lesion in a 52-year-old man, is reported including details of studies using lectin histochemistry, transmission electron microscopy (TEM), and immunohistochemistry. Most of the tumor cells, which appeared spindle-like with abundant rough endoplasmic reticulum and some microfilaments by TEM, showed immunoreactivity for mesenchymal markers. Some tumor cells, which were polygonal and contained many microfilaments and some filament bundles, were immunoreactive for muscle markers. The present case was considered to consist of many fibroblasts and some myofibroblasts.

Bicuspid↗

PubMed1997

Effect of estrogen on the development of disuse atrophy of bone and muscle induced by tail-supension in rats.

Rat tail-suspension induces disuse atrophy of muscles and bones in hindlimbs. In the present investigation we studied how ovariectomy and estrogen substitution affect the development of the disuse atrophy induced by suspension. Five-week old female Wistar rats were ovariectomized and divided into two groups. One group received intramuscular injection of estradiol dipropionate once a week (OVX-E2 group), and the other received a vehicle injection (OVX group). After the third injection, each group was further divided into two groups, tail-suspended and non-suspended. After 7 days of tail-suspension, a significant decrease in the wet weight of femurs and their Ca and Pi content was observed in the OVX group. However, no significant change in those parameters was observed in the E2 group. In both E2 and OVX groups, a significant decrease in the wet weight of soleus and gastrocnemius muscles was demonstrated after the suspension. This demonstrated that estrogen administration to ovariectomized rats prevents the development of disuse bone atrophy but not that of muscle atrophy, suggesting that estrogen plays important roles in bone remodeling.

Animals↗

PubMed1997

Effect of bisphosphonate administration on the excretion of stress hormones in tail-suspended rats.

We demonstrated that administration of a bisphosphonate, YH529, prevents the development of disuse atrophy of the hind limbs induced by tail-suspension in rats. Since tail suspension is accompanied by an increase in the secretion of stress hormones, we studied whether administration of bisphosphonate affects the secretion of stress hormones during that procedure. Tail suspension was carried out in a metabolic cage by connecting a wire inserted through tail bone to the ceiling of the cage. The control rat received the same treatment but was not suspended. YH529 or a vehicle (PBS=phosphate buffered saline) was administered daily starting 3 days before the commencement of tail suspension. Urine samples were collected before the wire was inserted (day 0), on the day of insertion (day 1) and 3, 5 and 7 days after. In the control rats receiving PBS, urinary excretion of corticosterone and epinephrine did not change throughout the 7-day experimental period. In the control rats receiving YH529, urinary excretion of corticosterone increased significantly on the day of tail-piercing and wiring but then returned to the prior level. This increase was not observed in the control group receiving PBS. In the tail suspended rats, excretion of corticosterone and epinephrine increased significantly in both PBS and YH529 groups, the highest level being observed on the first day of tail suspension. Although statistically not significant, corticosterone excretion on day 1 of tail suspension was higher in the YH529 groups than that in the PBS group. It is thus suggested that administration of YH529 causes an augmented response to stress load.

Animals↗

PubMed1997

Administration of bisphosphonate prevents disuse bone atrophy induced by tail suspension.

We recently demonstrated that osteopenia induced by rat tail-suspension was associated with an initial increase in bone resorption. To study the significance of the increase in early bone resorption for osteopenia, we investigated whether administration of YH529, a third-generation bisphosphonate, prevents the development of osteopenia as evidenced by increased wet weight of the femur, together with its calcium and phosphorus contents, when compared with those of tail-suspended rats treated with the vehicle alone. These results suggested that the initial increase in bone resorption plays an important role in the development of osteopenia induced by tail suspension.

Animals↗

PubMed1997

[Effect on 5'-deoxy-5-fluorouridine (5'-DFUR) of pyrimidine nucleoside phosphorylase (PyNPase), matrix metalloprotease and serum IAP values. Hokuriku Colorectal Cancer Chemotherapy Study Group].

PyNPase activity, MMPs activity and serum IAP values were measured in tumor tissues from colorectal cancer patients who had been divided into two groups, one given preoperative 5'-DFUR and the controls. PyNPase activity of the preoperative administration group was approximately equivalent to that of the controls. In the control group, correlations were assessed between PyNPase activity and activities of MMP1 and MMP3. To assess the effect of 5'-DFUR on the activity of MMPs, we divided patients into two groups, a high and a low PyNPase activity group. Although there was no correlation with MMPs activity of the preoperative administration group and the control group in the low PyNPase activity group, the activities of MMP1 and MMP9 of the control group were significantly higher in the high PyNPase activity group. Moreover, the serum IAP value of the administration group was significantly lower than that of the control group. These results indicated that PyNPase activity was thus suggested to be somehow related to MMPs activity and serum IAP values.

Adult↗

PubMed1997

[Evaluation of a new anti-cancer drug regimen against uterine cervical cancer in nude mice].

The purpose of this study was to describe a new anti-cancer drug regimen for uterine cervical cancer. The cytotoxicities of some anti-cancer drugs regimens against the human uterine cervical cancer xenografted into nude mice have been studied. The activities of CDDP, CPT-11, TXL, CDDP + BLM, CDDP + MMC, CPT-11 + BLM, CPT-11 + CDDP, CDDP + 5-FU, CPT-11 + MMC, CPT-11 + TXL and CDDP + TXL for squamous cell carcinoma (TCR, TCK, TCG), and CDDP, MMC, TXL, CDDP + TXL, CDDP + MMC and MMC + TXL for adenocarcinoma (TCO, TCM, TCY), were evaluated comparing with a control group using saline. Five mice were used for each groups. When the xenografted tumor reached 6 mm in diameter, 1/5 LD50 of these drugs were administered into the peritoneal cavity of the mice once a week for three weeks. The effective regimens were CDDP + MMC, CDDP + BLM, CDDP + CPT-11 and CPT-11 + MMC for squamous cell carcinoma of the uterine cervix. CDDP + MMC, CDDP + TXL, MMC + TXL and CDDP were effective for endocervical adenocarcinoma. It was suggested that these new drug regimens should be used in clinical studies.

Adenocarcinoma↗

PubMed1997

[Antinociceptive activity of intracisternal clonidine in the mouse].

The antinociceptive activities of clonidine have been determined against three qualitatively different noxious stimuli in the mouse. The methods used to evaluate this activity were selected to include tests which employ different types of noxious stimuli, i.e. heat (hot plate), chemical (acetic acid-induced writhing) and mechanical (tail pinch). Test drug and control treatments were given by cisternal injection in a dose volume of 10 microliters.mouse-1. The results presented here show that clonidine has potent antinociceptive properties against several types of noxious stimuli. Clonidine produced steep dose-response lines in all tests. The response to the writhing assays were completely inhibited by 1.0 microgram.mouse-1 of clonidine. In contrast in both the hot plate and tail pinch assay, however, clonidine did not produce a consistent antinociceptive effect at a dose of 200 micrograms.mouse-1. Utilizing these three different types of assays, the rank order of antinociceptive potency for clonidine in different noxia was the writhing >> hot plate > tail pinch. It was concluded from these results that clonidine has potent antinociceptive properties against chemical visceral stimuli.

Adrenergic alpha-Agonists↗

PubMed1997

Characterization of a newly established human tumor cell line (TEN) from a patient with clear cell carcinoma of the uterine body and its sensitivity to anti-cancer agents.

A cell line derived from human endometrial clear cell adenocarcinoma was newly established and named TEN. The tumor cells were obtained from uterine body of a 74-year-old who had been undergone an abdominal simple hysterectomy. The histologic features of the tumor cells showed abundant clear cytoplasm with diastase digested glycogen granule growing in solid nest and tubular pattern. The TEN cells were continuously propagated in vitro during the past 45 months and they were at 75th passage. They grew in a monolayered sheet with a doubling time of about 53 hours. The TEN cells resembled the structure of the original tumor and had abundant glycogen granules, lipid droplets in the cytoplasm. The histopathology of the transplanted tumor in SCID mice resembled that of the original tumors. The TEN cells secreted a high content of CA125. Immunohistochemically, the TEN cells had c-erbB-2 and Cathepsin D immunoreactivity in some parts of the cell population. But they did not have estrogen, progesterone and EGF receptor. Sensitivities of the TEN cells to a variety of anti-cancer drugs were examined. In in-vitro tests, MTT assays employed. The results suggested that the TEN cells were not sensitive to any of 13 agents. On the other hand, in-vivo sensitivity test of transplanted tumor in SCID mice, the tumors were sensitive to CPT-11 and paclitaxel. We conclude that the TEN cell line will be effective material for chemosensitivities against the endometrial clear cell adenocarcinoma.

Adenocarcinoma, Clear Cell↗

PubMed1996

Production of polyclonal antibody specific for human natriuretic peptide receptor B.

Polyclonal antibody against human natriuretic peptide receptor B (NPR-B) was produced using as immunogen a soluble chimeric protein consisting of the extracellular domain of the receptor fused with Fc portion of human IgG. The antibody was purified with protein A column, and then subjected to an adsorption of anti-Fc antibody using IgG column. The purified antibody recognized human NPR-B but not the related receptor NPR-A. The antibody inhibited C-type natriuretic peptide (CNP)-mediated intracellular cGMP accumulation in a dose-dependent manner. With regard to specific activity for the neutralization, the antibody purified with IgG column was significantly stronger than that before the adsorption step, indicating that the purification of the antibody with IgG column was extremely effective to remove the contaminating anti-Fc antibody from anti-NPR-B antibody. Western blot analysis using the purified antibody revealed that while the native NPR-B exists as an oligomer, the truncated NPR-B lacking most of its cytoplasmic domain is a monomer. This finding suggests that the cytoplasmic region may be involved in the oligomerization of the receptor. The results in this study demonstrate that soluble IgG fusion protein is very effective and useful for generating specific antibodies to the proteins expressed on cell surface.

Animals↗

PubMed1996

The immunosuppressive effects of a leukotriene B4 receptor antagonist on liver allotransplantation in rats.

The immunosuppressive effects of a leukotriene B4 (LTB4) receptor antagonist, ONO4057, on liver allotransplantation in rats were evaluated, and the levels of prostaglandin E2 (PGE2) in the liver tissue during rejection of the allografts examined. The rats were divided into four groups: group 1: Lewis rats (LEW) given a sham operation with dimethyl sulfoxide (DMSO); group 2: LEW given syngenic orthotopic liver transplantation (OLT) from LEW, with DMSO; group 3: LEW given allogenic OLT from ACI rats (ACI), with DMSO; and group 4: LEW given allogenic OLT from ACI, with ONO4057 as 10, 30, or 100 mg/kg per day dissolved in DMSO to subgroups 4a, 4b, and 4c, respectively. Histological examinations were performed, survival times monitored, and liver tissue PGE2 levels 3, 5, 7, and 14 days after transplantation measured. The mean graft survival times in groups 4a, b, and c, at 37.5 +/- 10.4, 52.2 +/- 24.4, and 34.0 +/- 4.9 days (mean +/- SEM), respectively, were significantly longer than that in group 3 (at 13.0 +/- 3.2 days). Moreover, the levels of tissue PGE2 in the liver allografts in group 4a were significantly higher than those in group 3 on days 5 and 7. These results suggest that ONO4057 has an immunosuppressive effect on liver allotransplantation since it reduces the activities of LTB4 which augments immune responses, and also because it indirectly increases the PGE2 level.

Alanine Transaminase↗

PubMed1996

Inhibition of 5-lipoxygenase promotes the regeneration of the liver after partial hepatectomy in normal and icteric rats.

The role of leukotriene (LT) on liver regeneration after hepatectomy is still unknown. LTB4 stagnates in the liver with obstructive jaundice, because LTB4 is excreted in the bile; therefore, LTB4 may have an effect on liver regeneration after hepatectomy with obstructive jaundice. Release of obstructive jaundice and simultaneous 70% hepatectomy was performed in rats to study the effect of 5-lipoxygenase inhibitor (AA-861) on liver regeneration. Group 1 underwent hepatectomy with administration of 0.1 mL dimethyl sulfoxide (DMSO), group 2 underwent hepatectomy with administration of AA-861 (20 mg/kg/d) dissolved in 0.1 mL DMSO, group 3 underwent hepatectomy with administration of AA-861 (40 mg/kg/d) dissolved in 0.1 mL DMSO, group 4 underwent release of obstructive jaundice and hepatectomy with administration of 0.1 mL DMSO, and group 5 underwent relief of obstructive jaundice and hepatectomy with administration of AA-861 (20 mg/kg/d). DMSO or AA-861 was administered 24 hours before, during, and 24 hours after hepatectomy in each group. Whole blood LTB4 and serum alanine aminotransferase (ALT), total bilirubin, and bromodeoxyuridine labeling index (LI) were measured before and after hepatectomy. The LTB4 level increased during obstructive jaundice and after hepatectomy. LTB4 and serum ALT levels were significantly lower after hepatectomy in the rats that were administered AA-861, and a significantly higher LI was observed at 24 hours after hepatectomy in rats receiving AA-861. Inhibition of 5-lipoxygenase promotes liver regeneration and decreases hepatocyte injury after hepatectomy associated with obstructive jaundice.

Alanine Transaminase↗

PubMed1996

Effects of bisphosphonate on bone metabolism in tail-suspended rats.

Our previous studies demonstrated that tail suspension causes early, transient increases in osteoclastic activity, followed by a decrease in osteoblastic activity in the hind limbs of rats. To assess whether this early increase in bone resorption is important in the development of disuse atrophy, the effect of YH529, a third generation bisphosphonate, was studied on hind limb atrophy in rats subjected to tail suspension. YH529 (YH group) or PBS (control group) were administered subcutaneously in 5-week-old male Wistar rats suspended for 7 days. In the control group, wet weight, calcium and phosphorus contents decreased significantly in the femur but they did not change in the humerus. In the YH group, however, these parameters did not change significantly in the femur, but both calcium and phosphorus increased significantly in the humerus. These results indicate that the inhibition of bone resorption by YH529 prevents the development of disuse atrophy induced by tail suspension. It is thus suggested that early increases in bone resorption are important for the development of disuse bone atrophy.

Animals↗

PubMed1996

Changes in serum concentrations of calcium and its regulating hormones during tail suspension in rats.

To study the effects of mechanical unloading on systemic calcium homeostasis, we determined the changes in serum concentration of calcium, 1,25-dihydroxyvitamin D3 and parathyroid hormone (PTH) during tail-suspension experiments in rats. The serum concentration of ionized calcium significantly increased during the 14 days of the suspension, reflecting increased bone resorption in the hind limbs. This hypercalcemic condition should cause suppression in PTH secretion. Indeed, serum PTH levels decreased on Day 3 of the suspension. This decrease was associated with lower serum levels of 1,25-dihydroxyvitamin [correction of dihyroxyvitamin] D3 probably due to a decrease in the activity of 1 alpha-hydroxylase in the kidneys resulting from a decrease in PTH secretion. Since it is known that 1,25-dihydroxyvitamin D3 stimulates osteoblastic function, it is suggested that endocrine responses evoked by tail suspension aggravate disuse atrophy of the hind limbs.

Amino Acids↗

PubMed1996

[Phase II study of paclitaxel (BMS-181339) in patients with ovarian cancer by 3-hour intravenous infusion].

A phase II study of Paclitaxel in patients with ovarian cancer by 3-hour intravenous infusion was undertaken by a cooperative study group of 30 institutes. Of 66 cases enrolled, 57 cases were evaluable for efficacy, and 63 cases were evaluable for safety. In spite of the fact that all cases for efficacy evaluation were previously treated with chemotherapy including platinum-based drugs, 2 cases of complete response (CR) and 15 cases of partial response (PR) were observed, with a response rate of 29.8% (The 95% confidence interval of response rate was 18.4-43.4%). Paclitaxel also showed 28.2% (11/39) response rate in patients refractory to treatment by platinum-based drugs. Histologically, the response rates were 28.9% (11/38) in serous adenocarcinoma, 40.0% (2/5) in clear cell adenocarcinoma and 25.0% (1/4) in mucinous adenocarcinoma. As the major laboratory abnormalities, leukopenia, neutropenia and decrease in hemoglobin were observed with incidence rates of 98.4% (62/63), 95.2% (59/62) and 85.7% (54/63), respectively. However, these abnormalities were clinically manageable by either withdrawal of medication, administration of antibiotics, G-CSF or metachysis etc. In addition, thrombocytopenia, elevation in GOT and GPT were seen with moderate incidence. Peripheral neuropathy was a major adverse symptom with an incidence of 79.4% (50/63), followed by alopecia, myalgia, arthralgia and fever. However, the majority of these adverse reactions were less than grade 3. From these findings, we confirmed that 3-hour intravenous infusion of Paclitaxel was a clinically useful chemotherapeutic agent in patients with ovarian cancer.

Adult↗