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Biomedical subjects

K Toyoda

Publications and source records attributed to K Toyoda.

At least 181 records · Page 10Linked to original sources
PubMed1989

[Treatment of hormonal refractory adenocarcinoma of the prostate with ifosfamide (IFM) and the combination of vincristine ifosfamide and peplomycin (VIP)].

Nineteen patients with hormonal refractory adenocarcinoma of the prostate were treated with ifosfamide (IFM) and the combination of vincristine, ifosfamide and peplomycin (VIP). Nine of them were treated with IFM, and nine with VIP, and one with IFM and also VIP. In the case of the IFM therapy, the over-all response rate was 0% by the Karnofsky's category of response, 20% by the response criteria of Shida et al., 50% by the National Prostatic Cancer Project (NPCP) criteria, and 0% by the response criteria of Koyama and Saito. In the case of the VIP therapy, the over-all response rate was 30% by the Karnofsky's category, 30% by the response criteria of Shida et al., 70% by the NPCP criteria and 20% by the response criteria of Koyama and Saitoh. The one-year survival rates of these patients treated with IFM and VIP were both about 20%. Only one patient treated with VIP therapy showed a partial response. Therefore, a more effective regimen for hormonal refractory adenocarcinoma of the prostate must be developed.

Adenocarcinoma↗
PubMed1989

[PVB therapy for advanced testicular cancer].

Twelve cases of advanced testicular cancer, including 5 cases of seminoma, 3 cases of teratocarcinoma, 1 case of yolk sac tumor, 1 case of embryonal carcinoma and 2 cases of mixed cell type, were treated with cisplatin-vinblastine-bleomycin (PVB) therapy. Among them, 10 cases had measurable metastatic lesions and the objective response rate was 80%. Three cases showed complete response. Ten cases showed nonexistent disease after PVB therapy and salvage operation. Though PVB therapy was useful for the treatment of advanced testicular cancer, a few cases having poor prognostic factors showed no response to the therapy.

Adult↗
PubMed1989

[Application of BrdU-immunohistochemistry and lanthanum-tracer methods to the pathological evaluation of 1,3-dinitrobenzene testicular toxicity].

The pathogenesis of 1,3-dinitrobenzene (1,3-DNB)-associated testicular toxicity was investigated in Sprague-Dawley rats with 5-bromo-2'-deoxyuridine (BrdU) immunohistochemistry and lanthanum-tracer methods as well as routine histopathological examination. Animals were killed at 8, 12, 24, 48 and 96 hr after a single oral administration of 1,3-DNB at a dose of 25 mg/kg. Histopathologically, severe alterations in the testes such as degenerating pachytene spermatocytes and giant cell formation were observed by 24 hr. Immunohistochemical analysis revealed no differences in the distribution of BrdU-positive cells between treated and control rats throughout the experiment. Thus it was concluded that 1,3-DNB exerted no effects on DNA synthesis in spermatogonia and preleptotene spermatocytes. Using the lanthanum-tracer method, it was shown that although lanthanum could penetrate the intercellular space from the basement membrane, the tight junction, consisting of fusions of contiguous Sertoli cell membranes, prevented further diffusion in both control rats and those killed at 8 hr after dosing. On the other hand, at 24 hr after dosing, lanthanum penetrated into the adluminal compartment beyond the tight junctions, thus demonstrating loss of integrity of the blood-testis barrier. The results suggested that the Sertoli cell is the primary target of 1,3-DNB testicular toxicity.

Administration, Oral↗
PubMed1989

[Analysis of renal calcification and stone formation in rats treated with ethoxyquin using X-ray analytical scanning electron microscopy: ultrastructural observations and element analysis].

Rat renal calcification and stone formation were investigated using a JEOL-JSM840A scanning electron microscope (SEM) equipped with a LINK-QX200J energy dispersed X-ray detector (EDX). Male Wistar rats were treated with 100 ppm N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in the drinking water or 10% NaCl in the diet for 8 weeks, and subsequently administered a dietary supplement of 0.1% ethoxyquin (EQ) for 32 weeks. An additional group received the EQ treatment alone. Calcification and stones were observed from the renal papilla to the pelvis region in all EQ treated groups. The incidence and grade of the lesion in the combined treated groups were much more greater than in the group treated with exposed to EQ alone. Ultrastructurally, microvilli on the surface of the renal papilla cells appeared degenerated or disappeared completely in the treated groups. Chemical element analysis of the renal stones revealed P and Ca to be the primary constituents. They were therefore considered to be of hydroxyapatite type.

Animals↗
PubMed1989

[Effect of vitamin A deficiency on PNUR-induced carcinogenesis in the rat upper digestive tract].

The effects of vitamin A (VA) deficiency on 1-propyl-1-nitrosourethan (PNUR)-induced tumorigenesis in the upper digestive tract were investigated in male F344 rats. Starting at 6 weeks old, animals were given PNUR in the drinking water (200 ppm) for one week, and starting 2 weeks later, were divided into 3 groups (30 rats/group) and maintained on VA-deficient diet, VA-supplemented diet (semipurified diet) or standard diet (CRF-1), respectively. An additional control group (10 rats) was fed VA-deficient diet without PNUR treatment. The experiment was terminated at 41 weeks after the beginning of PNUR administration, and development of tumors in the upper digestive tract was determined histopathologically. Squamous cell tumors were observed in the oral cavity, tongue and forestomach of all PNUR treated groups, while no tumors developed in the control group. Significantly higher incidences of forestomach papillomas were observed in the groups administered VA-deficient or VA-supplemented diets, as compared with that receiving standard diet (p less than 0.01, p less than 0.05, respectively). These results thus suggest that the higher incidences of forestomach tumors were probably due to general dietary differences (semipurified vs. standard diets) and not to the VA deficiency per se.

Animals↗
PubMed1989

[Regional distribution of perfusion and ventilation in hamartoangiomyomatosis of the lung].

We investigated regional distribution of perfusion and ventilation in three cases of hamartoangiomyomatosis (HAM) by 133Xe gas and 99mTc-MAA. In two cases, 133Xe washout were dominantly delayed in middle lung field and in the third case, it was delayed in upper lung field. This distribution was different from the result in the other chronic obstructive pulmonary disease (COPD). In most cases of COPD, 133Xe washout was prominently delayed in the lower lung field. Distribution of pulmonary perfusion in HAM were consistent with that of ventilation as in COPD.

Adult↗
PubMed1989

[Detection of precancerous lesions of the bladder by contact-micro-cystoscopy].

Contact-micro-cystoscopy is a new method to examine the bladder epithelium by micro-endoscope after staining. According to this method, normal epithelium was stained slightly and showed smooth surface and small, sparse nuclei. Neoplastic lesions were stained deeply and showed irregular surface and large, dense nuclei. One hundred and sixty nine biopsy specimens of cystoscopically normal bladder mucosa were analyzed. The diagnostic accuracy of neoplastic lesions by this method was 75.9%. In vivo mapping of the bladder epithelium was also possible using this method in association with random biopsy. Contact-micro-cystoscopy was thought to be useful to detect precancerous lesions or flat carcinoma of the bladder which was difficult to be detected by conventional cystoscopy.

Carcinoma in Situ↗
PubMed1989

[Complete remission of brain metastasis of bladder cancer treated by M-VAC therapy].

A case of brain metastasis from transitional cell carcinoma of the bladder that attained complete remission by methotrexate-vinblastine-adriamycin-cisplatin (M-VAC) therapy was reported. The patient was a 53-year-old male, already treated with total cystectomy and CAP therapy against pulmonary metastasis, which disappeared completely. At 8 months after complete remission of pulmonary metastasis, brain metastasis was found. One course of M-VAC therapy brought a complete remission persisting for 7 months. He is alive with no relapse.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1989

[Plain abdominal film after contrast-enhanced CT; re-evaluation by using iohexol].

Abdominal radiographs after enhanced CT were evaluated using non-ionic, low osmotic contrast media, iohexol. Comparison were made with iopamidol (non-ionic, low osmolality) and diatrizoate (ionic, high osmolality). Iohexol gave good opacification in nephrogram and persistent opacification till 45 min, after enhancement as well as iopamidol. Abdominal radiographs after enhanced CT using iohexol is useful for total observation of the urinary tract. There is no significant difference of serum BUN and creatinine between before and after enhancement in 21 iohexol.

Adolescent↗
PubMed1989

[Prognosis of bladder tumor patients treated by TUR].

One hundred and eleven cases of bladder tumors were treated with transurethral resection (TUR) and transurethral electrocoagulation as the initial treatment from 1974 and 1983. Eighty nine cases were male and 22 cases were female. The average age was 60.1 years old. Of the 111 patients, 57, 33, 2, 1 and 15 patients had a tumor of Ta, T1, T2, T3a and Tx respectively. The number of grades G0, G1, G2, G3, GX cases was 1, 38, 40, 17, 12, respectively. Other than these, 2 cases of squamous cell carcinoma and 1 of adenocarcinoma were included. The actual survival rates for 5 years in Ta and T1 were 84.4 and 88.9% respectively, and the relative survival rates were 99.5 and 109.1%. TUR was recommended for superficial bladder tumor because of good prognosis. The 5-year recurrence rates for single tumors with and without prophylactic bladder instillation were 21.4 and 27.5% respectively, and those for multiple bladder tumors were 58.6 and 51.8%. There was no significant difference between the group with and without bladder instillation.

Adenocarcinoma↗
PubMed1988

Carcinogenicity study of tetramethylthiuram disulfide (thiram) in F344 rats.

The carcinogenic potential of tetramethylthiuram disulfide (thiram) was examined in F344 rats. Groups of 50 male and 50 female rats were given thiram in their diet at concentrations of 0.1% and 0.05% for 104 weeks. Similar numbers of male and female rats received the basal diet throughout the experiment. All surviving rats were sacrificed at week 112. The rats given the chemical at 0.1% showed reduced body weight gain, especially in females, and liver dysfunction in biochemical examination of blood in males. Histopathologically, however, no significant lesions or tumor induction attributable to the treatment were observed in any tissue except for dose-dependent reduction of spontaneous leukemia in both sexes and slightly reduced incidences of pituitary and thyroid adenomas in females. Under the present experimental conditions, thiram was not carcinogenic in F344 rats.

Animals↗
PubMed1988

Study for tumor-initiating effect of acetaminophen in two-stage liver carcinogenesis of male F344 rats.

The potential liver-tumor-initiating activity of acetaminophen (paracetamol, APAP) was investigated in male F344 rats. APAP was administered by intragastric intubation either as 10 doses of 1 g/kg body weight over 5 weeks or as a single dose of 0.5 g/kg body weight 24 h after two-thirds partial hepatectomy. These initiating treatments were followed by administration of 0.1% phenobarbital in the drinking water for 12 weeks as the promoting regimen. Quantitative examination of placental glutathione S-transferase-positive foci revealed no enhancing effect of APAP on the induction of the foci consisting of more than two positive cells with either initiating treatment. If solitary positive hepatocytes were included in the effective number of foci, 10 repeated doses of 1 g/kg APAP increased the number of foci while the validity of the single positive cells is uncertain. This dose of APAP caused centrilobular necrosis. By 32P-postlabeling, although the active metabolite of APAP formed DNA adducts when incubated with isolated DNA, no DNA adduct formation was detected in the liver of rats either fed 0.1-1.5% APAP for 1 week or given 1 g/kg by gastric intubation. These results indicate that APAP possesses no tumor-initiating activity in the rat liver.

Acetaminophen↗
PubMed1988

Co-carcinogenic effect of retinyl acetate on forestomach carcinogenesis of male F344 rats induced with butylated hydroxyanisole.

The potential modifying effect of retinyl acetate (RA) on butylated hydroxyanisole (BHA)-induced rat forestomach tumorigenesis was examined. Male F344 rats, 5 weeks of age, were maintained on diet containing 1% or 2% BHA by weight and simultaneously on drinking water supplemented with RA at various concentrations (w/v) for 52 weeks. In groups given 2% BHA, although marked hyperplastic changes of the forestomach epithelium were observed in all animals, co-administration of 0.25% RA significantly (P less than 0.05) increased the incidence of forestomach tumors (squamous cell papilloma and carcinoma) to 60% (9/15, 2 rats with carcinoma) from 15% (3/20, one rat with carcinoma) in the group given RA-free water. In rats given 1% BHA, RA co-administered at a dose of 0.05, 0.1, 0.2 or 0.25% showed a dose-dependent enhancing effect on the development of the BHA-induced epithelial hyperplasia. Tumors, all papillomas, were induced in 3 rats (17%) with 0.25% RA and in one rat (10%) with 0.05% RA co-administration. RA alone did not induce hyperplastic changes in the forestomach. These findings indicate that RA acted as a co-carcinogen in the BHA forestomach carcinogenesis of the rat.

Animals↗
PubMed1988

[The primary mucinous adenocarcinoma of renal pelvis: a case report].

A case of primary mucinous adenocarcinoma of the renal pelvis is reported. A 55-year-old man visited our clinic with lumbar pain. He had a history of left renal stone and had left partial nephrectomy four years previously. Physical examination revealed a hard, child-head-sized, unmovable and uneven tumor in the left side of the abdomen. Intravenous pyelography revealed the non-functioning left kidney with calcification, in which hydronephrosis was detected by computed tomography. In transabdominal sonography a huge mass with mixed echo pattern was observed. Aspiration biopsy under interventional ultrasound was performed, aspirating yellow-white semi-transparent mucinous substance, which was highly suspicious of malignancy by cytology. He died 74 days after the first admission. Autopsy revealed primary mucinous adenocarcinoma of the renal pelvis. This was thought to be the 14th case of primary mucinous adenocarcinoma of the renal pelvis reported in the Japanese literature.

Adenocarcinoma, Mucinous↗