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Biomedical subjects

M Arai

Publications and source records attributed to M Arai.

At least 685 records · Page 38Linked to original sources
PubMed1981

[FHR long term variability under various obstetrics analgesia (author's transl)].

Changes of FHR long term variability (LTV) were studied in four groups of patients under different types of analgesia. The LTV was evaluated according to our visual criteria in each episode of more than one minute of duration on baseline fetal heart rate level between contractions. In the balanced anesthesia group incidence of the episodes with LTV decreased significantly after the administration of Diazepam and Methoxyflurane (64%-30%), further decreasing after the injection of Pethilorfan, but it increased to some degree within 20 min. before delivery. In the epidural group the change of LTV was mild, but the LTV decreased after each administration of 0.25% Bupivacaine (58%-44%-36%). It is also showed mild increase within 20 min. before delivery. Loss of variability was persistently noted until the end of labor from 20-40 min. after the administration of Diazepam and Pentazocine in the modified NLA group. The change in paracervical block group was quite different from the other groups. The incidence of episodes with LTV was increased after the injection of 1% Lidocaine Hydrochloride (35%-41%). There was no significant different of blood gas and acid-base balance among four types of analgesia.

Anesthesia, Epidural↗
PubMed1981

Scanning electron microscopy of cyclophosphamide-induced hyperplasia of the rat urinary bladder.

Urinary bladder damage caused by cyclophosphamide in male F344 rats was studied by light microscopy, scanning electron microscopy, and autoradiography. Cyclophosphamide was injected intraperitoneally at doses of 50, 75, 100, 150, and 200 mg. per kg. of body weight, and rats were killed at several intervals following treatment. Extensive necrosis of the bladder was followed by regenerative hyperplasia of the epithelium. A dose response was evident in the number and size of lesions induced and the time of regeneration and repair. Scanning electron microscopy disclosed pleomorphic microvilli on the luminal surface of cells during the early phases of hyperplasia. The greatest number of cells with pleomorphic microvilli occurred 2, 5 and 7 to 8 days following injection of 75, 100, and 200 mg. per kg. of cyclophosphamide, respectively. The hyperplastic lesions also had cells with short, uniform microvilli and ropy or leafy microridges on their surfaces. Autoradiographs of the urinary bladders showed marked labeling of epithelial cells in the early phase of hyperplasia. Of the few rats surviving beyond 1 year after a single injection, none had bladder lesions at any of the dose levels. The changes in the epithelium observed by scanning electron microscopy following cyclophosphamide injection were compared to those observed during bladder carcinogenesis.

Animals↗
PubMed1980

Effects of caffeine and saccharin on DNA in the bladder epithelium of rats treated with N-butyl-N-(3-carboxy-propyl)-nitrosamine.

The damage to DNA caused by N-butyl-N-(3-carboxypropyl)-nitrosamine (BCPN), saccharin and caffeine in the urinary bladder epithelium of female rats and its subsequent repair was investigated using alkaline sucrose density gradient analysis with a fluorimetric procedure for DNA determination and light and electron microscopy. Exposure of the bladder epithelium to 50 mg/kg body wt. of BCPN solution for 5 min resulted in serious damage of DNA within 2 h. Subsequent repair of most of the DNA damage, as indicated by reconversion of low molecular weight DNA fragments to larger ones, began after 6 h, and appeared to be complete after 48 h. Caffeine and saccharin induced no remarkable changes in the sedimentation profiles of DNA of the epithelial cells, with or without pretreatment of the cells with BCPN (administered to rats as 0.05% BCPN in the drinking water for 4 weeks). These results were confirmed by light and electron microscopy.

Animals↗
PubMed1980

Chronic effects of norharman in rats treated with aniline.

The carcinogenic effects of aniline and norharman given alone or in combination were examined in rats. Neoplastic changes including hyperplastic changes of the urinary bladder were not found in all groups. Papillomas of forestomach were observed in 5 rats out of 110 rats. However, this was not significantly different among the groups. Pyelonephritis or chronic nephritis were also seen in all groups. Hematological and blood biochemical analysis did not show any notable difference in the animals treated with aniline and/or norharman.

Alkaloids↗
PubMed1980

Malioxamycin, a new antibiotic with spheroplast-forming activity. I. Producing organism, fermentation, isolation and characterization.

Strain No. 15748, identifies as Streptomyces lydicus, produces a new antibiotic malioxamycin. Malioxamycin is a water-soluble, amphoteric antibiotic with low molecular weight, having a valine and a malic acid moieties in its structure. It gave a positive ninhydrin and ferric chloride reactions. Malioxamycin inhibited the growth of some Gram-negative bacteria by acting on peptidoglycan synthesis in the cell wall and produced spheroplasts from those sensitive bacteria.

Anti-Bacterial Agents↗
PubMed1980

Malioxamycin, a new antibiotic with spheroplast-forming activity. II. Structural elucidation and total synthesis.

Malioxamycin (1) is a new antibiotic produced by Streptomyces lydicus No. 15748. The structure of malioxamycin has been determined by nmr and mass spectra to possess a hydroxamic acid bond between L-valine and D-malic acid. This structure was confirmed by total synthesis of the antibiotic with (R)-aminooxysuccinic acid and the active ester of L-valine.

Anti-Bacterial Agents↗
PubMed1980

A new sesquiterpene antibiotic, heptelidic acid producing organisms, fermentation, isolation and characterization.

A new sesquiterpene antibiotic, heptelidic acid, was found in the culture filtrate of three different strains of fungi isolated from soil samples. These strains were identified as Gliocladium virens, Chaetomium globosum and Trichoderma viride. Heptelidic acid was produced by conventional submerged culture and purified by successive column chromatography on silica gel and Sephadex LH-20 and finally by preparative TLC on silica gel. The molecular formula of heptelidic acid was determined as C15H20O5 on the basis of elementary analysis and high resolution mass spectrometry of its monomethyl ester. The antimicrobial spectrum of the antibiotic revealed its specific activity against anaerobic bacteria, especially against Bacteroides fragilis.

Animals↗
PubMed1980

Inhibitory effect of an aromatic retinoic acid analog on urinary bladder carcinogenesis in rats treated with N-butyl-N-(4-hydroxybutyl)nitrosamine.

The inhibitory effect of an aromatic retinoic acid analog, ethyl all-trans-9-(4-methoxy-2,3,6-trimethylphenyl)-3,7-dimethyl-2,4,6,8-nonatetraenoate, on bladder carcinogenesis in rats treated with N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) was evaluated. Administration of 50 ppm of aromatic retinoid in the diet before BBN in the drinking water reduced the incidence of papillary or nodular hyperplasia as a preneoplastic lesion of the bladder epithelium (P < 0.05). When given before, during or after BBN, it also greatly reduced the incidence of papilloma (P < 0.001 before BBN, P < 0.01 during or after BBN treatment), and slightly inhibited the development of cancer. Administration of 100 ppm of aromatic retinoid before or during BBN administration also reduced the incidences of papillary or nodular hyperplasia (P < 0.01 before BBN, P < 0.05 during BBN treatment), and its administration before, during or after BBN treatment greatly reduced the incidences of papilloma (P < 0.001), and cancer (P < 0.01 before or after BBN, P < 0.001 during BBN treatment). Similar results were obtained by assessing the effect of the retinoid on the average numbers of various epithelial lesions per 10 cm length of basement membrane of the bladder in tissue slices. These results show that the aromatic retinoid inhibits both the initiation and promotion of bladder carcinogenesis induced in rats by BBN, and that its effect is dose-dependent.

Animals↗
PubMed1980

Inhibition by an aromatic retinoid of DNA damage induced by the bladder carcinogen N-butyl-N-(3-carboxypropyl)nitrosamine.

The reversible inhibitory action of an aromatic analog of retinoic acid, ethyl all-trans-9-(4-methoxy-2,3,6-trimethylphenyl)-3,7-dimethyl-2,4,6,8-nonatetraenoate (aromatic retinoid) on bladder carcinogenesis was studied by biochemical and histopathological methods. fischer 344 female rats were fed a diet containing the aromatic retinoid (0, 12.5 or 50 ppm) for 56 days. On day 57, 60 or 70, 50 mg/kg body weight of N-butyl-N-(3-carboxypropyl)nitrosamine (BCPN) in a volume of 0.3 ml was directly instilled intravesically through a urethral catheter. DNA damage in rat bladder epithelial cells 2, 24 and 48 hr after administration of BCPN was examined by measuring the change in sedimentation profile of the DNA in 5 approximately 20% alkaline sucrose gradients. DNA sedimentation was measured by a fluorometric procedure. Histopathological examination of the bladder epithelium was performed at the same time. Two hours after a 5-min exposure to BCPN, DNA damage at the urothelium was observed in rats fed the diet without the aromatic retinoid, but the damage was repaired after 24 and 48 hr. The highest dose of the aromatic retinoid almost completey prevented DNA damage by BCPN on days 57 and 60. A lower dose of the aromatic retinoid did not prevent DNA damage by BCPN on days 57, 60, and 70, while the higher dose did not prevent damage by BCPN on day 70. No histological changes were observed in the urothelium of rats treated with the aromatic retinoid and BCPN, and electron microscopy showed that the epithelium also remained normal. DNA damage was induced by BCPN at the urothelium, and the damage was inhibited by previous administration of the aromatic retinoid.

Animals↗
PubMed1980

Effects of sodium saccharin and caffeine on the urinary bladder of rats treated with n-butyl-n-(4-hydroxybutyl)nitrosamine.

The effects of sodium saccharin and caffeine on urinary bladder carcinogenesis in Wistar strain rats treated with N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) were studied. Animals were given 0.01% BBN as an initiator for 4 weeks and then sodium saccharin and/or caffeine as promoters for 32 weeks (Experiment I), or were treated simultaneously with 0.001% BBN, sodium saccharin and/or caffeine for 40 weeks (Experiment II). The urinary bladders were then removed and examined by light and electron microscopy. Sequential administration of sodium saccharin after BBN significantly enhanced the induction of hyperplasias compared with administration of BBN alone (Experiment I), and simultaneous administration of sodium saccharin with BBN significantly enhanced the induction of hyperplasia and papillomas compared with BBN alone (Experiment II). Two types of hyperplasias developed in the urinary bladder of rats treated with sodium saccharin alone in both experiments. Caffeine alone had no effect on the rat urinary bladder epithelium, and either sequential or simultaneous administration of caffeine with BBN caused no marked enhancement of carcinogenesis in these experiments.

Animals↗