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Biomedical subjects

M Ohtani

Publications and source records attributed to M Ohtani.

At least 253 records · Page 14Linked to original sources
PubMed1985

Correlation of results of agglutination assays with concanavalin A and carcinogenesis experiments on promoters of bladder cancer.

The promoting effects of various chemicals and dietary constituents on bladder carcinogenesis were examined by means of a short-term assay, in which maintenance of concanavalin A agglutination of isolated rat bladder cells caused by a subcarcinogenic dose of N-butyl-N-(4-hydroxybutyl)nitrosamine was used as an indicator. Twenty-seven chemicals were examined as possible promoters. Positive results in this assay were consistent with established promoting effects in the cases of sodium saccharin, saccharin, sodium L-ascorbate, sodium cyclamate, DL-tryptophan, butylated hydroxyanisole, butylated hydroxytoluene, L-thioproline and phenacetin. Allopurinol was the only established promoter that gave negative results in the agglutination assay. Thus, this method is useful for rapid evaluation of the specific promoting effect of a chemical on bladder carcinogenesis.

Agglutination Tests↗
PubMed1985

[Subfrontal schwannoma: report of a case].

Subfrontal schwannoma is extremely uncommon. By reviewing the literature, we are able to find 8 previously described cases. This report describes a very rare case of solitary schwannoma grown in the anterior cranial fossa. A patient, 23 years old male, had experienced generalized convulsion on April 4, 1981. On the Tc99m scintigram, accumulation of isotope was observed in the left anterior cranial fossa. The carotid angiography revealed that the tumor stain was supplied from ophthalmic artery and orbitofrontal artery. CT showed an area with relatively low density in the left frontal base. This area was well enhanced following contrast injection. Coronal CT revealed that the tumor was contiguous with the left olfactory groove. The tumor was removed on May 12, 1981. The left fronto-temporal post-operative epidural hematoma was observed after the operation but his post-operative course was relatively satisfactory. Histological section of tumor showed interwinning bundles of cells with pallisading on hematoxylin and eosin. Pathological study showed such pallisading of the tumor cells, which confirmed that the tumor was schwannoma. While the precise origin of this unusually situated schwannoma remains uncertain, it appears most likely that the origin was from either ectopic, or perivascular nerve plexus schwann cells or dural branch of trigeminal nerve. Because the branch of the trigeminal nerves or anterior ethmoidal nerves is distributed to the meninges, the trigeminal nerve is covered with schwann cells after penetrating the pia mater in the anterior cranial fossa.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Effects of intravesical instillation of antitumor chemotherapeutic agents on bladder carcinogenesis in rats treated with N-butyl-N-(4-hydroxybutyl)nitrosamine.

The effects of intravesical instillation of Adriamycin (doxorubicin) (ADR), and mitomycin C (MMC), as inhibitors of development of rat bladder tumors, were examined in rats treated with N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN). Intravesical instillation of ADR or MMC once a week for 12 weeks into rats pretreated with BBN for 4 weeks markedly enhanced development of bladder tumors. That is, one week after the end of intravesical instillation of these compounds the incidence of papillary or nodular hyperplasias, namely preneoplastic lesions, was significantly increased, and at the end of the experiment the incidence of not only papillary or nodular hyperplasias but also of papillomas and cancers was significantly increased. These results indicate that the intravesical instillation of ADR or MMC promotes two-stage bladder carcinogenesis in rats.

Animals↗
PubMed1984

Characteristic findings of metrizamide CT cisternography in epidermoids.

The characteristic findings of metrizamide CT cisternography in two cases of epidermoid are reported. The main finding was a "cauliflower-like" appearance and was thought to be caused by the irregular interstices of epidermoids. Metrizamide CT cisternography may be helpful in making a diagnosis of an epidermoid.

Adolescent↗
PubMed1984

Chemotherapy by bronchial arterial infusion for pulmonary metastases of renal cell carcinoma.

Bilateral multiple pulmonary metastases of renal cell carcinoma were treated by repeated bronchial arterial infusion of chemotherapeutic drugs, such as mitomycin C, carboquone, doxorubicin and nitrosourea. Of 12 patients treated 2 had a complete response, 3 had a partial response, 2 had no change and 5 had progression of the disease. The over-all response rate was 42 per cent. Since metastatic renal cell carcinoma is unresponsive to ordinary treatment bronchial arterial infusion alone or in combination with an operation appears promising.

Adenocarcinoma↗
PubMed1984

Effects of metal-containing drugs taken simultaneously with clioquinol upon clinical features of SMON.

In order to explore the effects of metals upon the subsequent onset of several clinical events in SMON, a retrospective cohort study was attempted. Study subjects were 216 "exposed" patients and 149 "unexposed" patients. "Exposure" was defined as the simultaneous ingestion of metal-containing drugs with clioquinol before the onset of neurological disorders. These two cohorts were identified from 531 patients among 832 patients, collected by the nationwide survey in 1975 and 1976. Effects provoked by ingestion of five metals (alminum, calcium, magnesium, copper and bismuth) were evaluated by relative risks with and without adjustment of the total amount of clioquinol ingested. Adjusted relative risks were estimated by maximum likelihood method. Significance of relative risk was determined by its 95% confidence interval. Following major findings emerged from the present analysis. (1) Simultaneous ingestion of Al-, Ca-, Mg-, Cu- or Bi-containing drugs with clioquinol significantly reduced the risk of developing motor disturbances. (2) Risk of developing visual disturbances were favorably modified by Al-containing drugs. (3) Clinical severity was significantly reduced by ingestion of Al-, Ca-, Mg- or Bi-containing drugs. (4) About 2-fold increase in risk of unfavorable clinical course was demonstrated by Al-containing drugs. (5) Onset of both green-fur on the tongue and relapse appeared unrelated to the metal-containing drugs ingested. (6) Combined ingestion of two kinds of metal-containing drugs with clioquinol appeared to yield more favorable effects than single ingestion of metal-containing drugs. (7) Al- or Bi-containing drugs demonstrated the strongest association with clinical features of SMON, followed by the drugs containing Mg or Ca. Cu-containing drugs had little association.

Clioquinol↗
PubMed1984

[Reconstructive valve surgery in congenital heart disease].

As part of various defects in congenital heart disease, valvular lesions are frequently encountered and remain as one of the difficult subjects. Recent advances in the management of valvular lesions and late results of repair and replacement were reported. In congenital aortic stenosis, most of patients have obtained satisfactory results with valvotomy, but some required reoperation with valve replacement even during childhood. In supracristed VSD associated with aortic regurgitation, late recurrence of regurgitation was found in some, but 70% of the patients showed free of diastolic murmur after 10 years. In tetralogy of Fallot, definitive repair of pulmonary valve was performed in last 5 years with composite patch with patient's own pericardium to reduce postoperative pulmonary regurgitation. Recently, pericardium is treated with glutaraldehyde on the operating table to prevent late shrinkage. As external conduit, homograft aorta, which had been utilized previously, showed good late results comparable to xenograft in terms of free from reoperation. Xenograft has been frequently utilized without significant late obstruction so far. In atrioventricular canal, endocardial cushion prosthesis technique has been utilized satisfactory with recent modification of the wings made by glutaraldehyde treated patient's own pericardium as well as in tetralogy.

Follow-Up Studies↗
PubMed1983

Effects of intravesical instillation of antitumor drugs on the induction of preneoplastic bladder lesions in rats.

The effects of adriamycin (ADR) and mitomycin C (MMC) as inhibitors of the development of bladder tumors in rats were studied. Six-week-old female F344 rats were divided into nine groups, five of which received 0.05% N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) in their drinking water for the first 4 weeks, no treatment for 1 week, and then intravesical instillation once a week of ADR, MMC, or physiological saline or no instillation (no catheterization) for 12 weeks. The other four groups received no BBN for the first 5 weeks of the experiment and then received ADR, MMC, or physiological saline as above for 12 weeks. The bladders were examined by light microscopy 17 weeks after the beginning of the experiment. Results showed that development of preneoplastic lesions induced in the bladders of the rats by BBN was stimulated by subsequent instillation of ADR or MMC. This result suggests that ADR and MMC have promoting activities in bladder carcinogenesis of rats.

Animals↗
PubMed1983

Synthesis and substituent effects on antibacterial activity, alkaline hydrolysis rates, and infrared absorption frequencies of some cephem analogues related to latamoxef (moxalactam).

Relationships between intrinsic antibacterial activity and beta-lactam reactivity of 7 beta-[(4-hydroxyphenyl)acetyl]amino- and 7 beta-[(4-hydroxyphenyl)malonyl]amino derivatives of 1-oxa- and 1-thiacephems, with or without the 7 alpha-methoxy group (1-8), were investigated in order to clarify the enhanced antibacterial activity of latamoxef disodium (1). Substituent effects of a carbon atom at the 1- and 7 alpha-positions were also investigated by using racemic 1-carbacephem 9 and 7 alpha-methyl-1-oxacephem 10. Syntheses of 2-8 and 10 are also described. Acid chlorides derived from the O-benzyloxycarbonyl derivative of (4-hydroxyphenyl)acetic acid and the p-methoxybenzyl derivative of (4-hydroxyphenyl)malonic acid smoothly effected the introduction of these side chains. Conjugate addition of lithium dimethylcuprate to the quinoid system in 16 proceeded stereospecifically, furnishing the 7 alpha-methyl group for the synthesis of 10. Values of log (1/C) averaged for the sensitive Gram-negative strains (Escherichia coli NIHJ JC-2 and Klebsiella pneumoniae SRL-1) were taken as an estimation of the intrinsic antibacterial activity. The chemical reactivity of the beta-lactam ring was estimated either by pseudo-first-order rate constants (k) of alkaline hydrolysis measured at pH 9.20 and 35.0 degrees C or by infrared stretching frequencies of the beta-lactam carbonyl measured in dimethyl sulfoxide. Substitution of an oxygen atom at the 1-position increases both the hydrolysis rates and the antibacterial activity by a factor of approximately 6.3, while substitution of a 7 alpha-methoxy group increases the antibacterial activity by a factor of approximately 3.2 without significant change in the hydrolysis rates. The effect of the 7 alpha-methoxy group on the transition state in alkaline hydrolysis is discussed. Substitutions at the 1-position with a methylene group and, especially, at the 7 alpha-position with a methyl group greatly diminished the antibacterial activity, whereas the hydrolysis rate remained high with the substitution of a methylene group. Substitution of an oxygen atom for the sulfur atom at the 1-position of 1-thiacephems increased the beta-lactam carbonyl frequencies by approximately 6 cm-1, whereas introduction of a 7 alpha-methoxy group in 1-thia- and 1-oxacephems reduced the frequencies by approximately 5 cm-1.

Anti-Bacterial Agents↗
PubMed1983

Promoting activities of butylated hydroxyanisole and butylated hydroxytoluene on 2-stage urinary bladder carcinogenesis and inhibition of gamma-glutamyl transpeptidase-positive foci development in the liver of rats.

Butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) were evaluated for possible promoting activity for urinary bladder carcinogenesis in male F344 rats initiated by N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN). The rats were treated with 0.01 or 0.05% BBN in the drinking water for 4 weeks and then administered 2% BHA or 1% BHT in the diet for 32 weeks. Surviving rats were killed at the end of week 36 of the experiment. The incidences of cancer and papilloma and the average number of cancers, papillomas and papillary or nodular hyperplasias (PN hyperplasias) per 10 cm of basement membrane were significantly increased in the group receiving BHA following initiation by 0.05% BBN compared with the group given BBN only. BHT also significantly increased these lesions of the bladder, but not the average number of cancers, in rats treated with 0.05% BBN. The ability of four antioxidants, BHA, BHT, sodium L-ascorbate (ascorbate) and ethoxyquin, to promote the induction of gamma-glutamyltranspeptidase (gamma-GT)-positive foci initiated by diethylnitrosamine (DENA) in the liver of F344 rats was tested. Rats were given a single i.p. injection of 200 mg/kg body weight of DENA, and 2 weeks later the animals were exposed to 2% BHA, 1% BHT, 5% ascorbate or 1% ethoxyquin, respectively, in the diet for 6 weeks. All animals were subjected to partial hepatectomy at the end of week 3. The number of gamma-GT-positive foci in the groups fed either BHA, BHT or ethoxyquin after DENA were significantly decreased compared with the control group. These findings show that BHA and BHT are promoters for the urinary bladder carcinogenesis initiated by BBN, but that these and other antioxidants significantly inhibit the induction of gamma-GT-positive foci in the liver.

Acyltransferases↗
PubMed1983

Stricture of the anterior urethra following estrogen therapy in patients with prostatic cancer.

A high incidence of urethral strictures was noted in patients with prostatic cancer who were treated by antiandrogen therapy. Retrograde urethrograms showed urethral stricture in 24 of 42 patients (57%) after or during the therapy, despite the fact that no stricture was found before initiation of therapy. The stricture was long and the entire penile urethra was narrowed, associated with more severely constricted portions. All of the patients with urethral stricture had received estrogens, while none of the patients who had undergone castration alone or had not received any therapy showed a stricture. The strictures disappeared after the cessation of estrogen administration. These results indicate that estrogen administration induces stricture in the male anterior urethra. It is suggested that large amounts of estrogen cause atrophy and fibrosis of the spongy and cavernous bodies of the penis, depriving the urethra of its normal elasticity, which results in urethral stricture. The stricture is one of the complications of estrogen therapy for cancer of the prostate.

Aged↗