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Biomedical subjects

K Ohsawa

Publications and source records attributed to K Ohsawa.

At least 109 records · Page 6Linked to original sources
PubMed1988

The usefulness of alkaline solutions for clearing the uterus and staining implantation sites in rats.

The alkaline solution method for detecting uterine implantation sites (metrial glands or spots after delivery), which indicate the position of the embryo, was compared with conventional methods using Turnbull blue (Salewski's technique) and benzyl benzoate (Orsini's technique) in rats. When rat uteri were immersed directly in 2% sodium hydroxide [NaOH], potassium hydroxide [KOH] solution or one of several other alkaline solutions for one hour, the uteri were cleared. Then the metrial glands could be observed without further staining, and the spots after delivery with further staining. After alkaline treatment, unstained metrial glands appeared as yellowish-white degenerated masses and stained spots after delivery appeared as yellowish-brown patches covered with yellowish-white lumps. These yellowish-brown or yellowish-white sites were probably stained by the iron in hemosiderin deposits in the placental scar or in a vestige of the metrial glands left over from pregnancy. Formalin-fixed uteri were not cleared by immersion in a high concentration of NaOH, KOH or other alkaline solutions, but the spots after delivery were stained by this treatment. Turnbull blue did not stain the metrial glands, which contain no iron. Benzyl benzoate cleared fixed or unfixed uteri and allowed observation of the metrial glands and spots after delivery although the entire process required a few days and the specimens became hard and shriveled. The best and most convenient solution for clearing the rat uterus and for staining implantation sites was 2% NaOH or KOH.

Animals↗
PubMed1988

The effects of oxygen toxicity on the pregnant rat using an apparatus designed to measure oxygen consumption method.

To evaluate the effects of oxygen toxicity in the pregnant rat at high and low concentrations of oxygen, an oxygen-consumption apparatus was devised to measure the consumption of oxygen continuously over long periods. Oxygen consumption, partial oxygen pressure on the skin (tcPo2), and lipid peroxide levels in the serum were measured. There was a close correlation between oxygen consumption and body weight of rats that weighed between 150 g and 450 g. Oxygen consumption during the later stages of pregnancy increased by 1.8 ml/day, an increase of 8%. Oxygen consumption by rats during parturition increased markedly for up to 1 h and then reached and remained at a plateau value until the end of delivery. Exposure of pregnant rats to low concentrations of oxygen resulted in a marked depression in oxygen consumption and tcPo2 during the exposure time. A significant increase in the lipid peroxide level in serum was observed in the mother rat after birth and in the newborn offspring of pregnant rats exposed to 16% oxygen for 3 h.

Animals↗
PubMed1987

[Effect of sex-hormone on composition of rat skin surface lipid].

The optimum analytical conditions for studying the composition of skin surface lipid were examined by high-performance liquid chromatography equipped with a photo-diode array detector. Optimum conditions were as follows: ULTRON N-C18 (150 x 4.6 mm) as stationary phase, acetonitrile/tetrahydrofuran/water (55/35/10, V/V) as eluent at the flow rate of 1.0 ml/min, and column temperature of 40 degrees C. The peaks were detected by monitoring the absorbance at 210 nm. Effect of sex-hormone on composition of skin surface lipids was examined. Gonadectomized Sprague-Dawley rats were injected with either testosterone (50 mg/kg, s.c.) or estradiol (5 mg/kg, s.c.) for 12 days. Amount of crude lipid from the skin surface was decreased at 8 days after castration; estradiol dosing to castrated rats also decreased the amount. The other hand, in ovariectomized rats, testosterone injection increased skin surface lipids. It is recognized that sex-hormone dosing after gonadectomy changes the percentage composition of squalene and cholesterol in male rats, but does not charge them in females.

Animals↗
PubMed1986

[Development of a suction device for sampling of skin surface lipids].

By the analysis of skin surface lipids, the activity of the sebaceous glands in normal or abnormal conditions and the functions of skin surface lipids can be studied. There are various methods to collect skin surface lipids, e.g., the cup method, etc. Among all of these methods, the most widely used is the cup method, which gives excellent accuracy and reproducibility. However, the use of this method is painful for the subject, and it is difficult to use on small animals. To overcome these disadvantages, a new device for the sampling of skin surface lipids was made and compared with the cup method. The device consisted of a cell and a collector. The cell was fixed in the sampling position, vaccumed by an aspirator, and as solvent flowed through the cell, the skin surface lipids were collected. By this suction method, the same degree of accuracy and reproducibility as the cup method was obtained. The use of this device allows a reduction of sampling time, removal of samples from any part of the body and experiments on most small animals. Also the discomfort of the subject is reduced.

Adult↗
PubMed1985

Synergistic stimulation of VIP/PHM-27 gene expression by cyclic AMP and phorbol esters in human neuroblastoma cells.

The effects of dibutyryl cAMP (Bt2cAMP) and phorbol esters such as 12-O-tetradecanoylphorbol-13-acetate (TPA) and phorbol-12,13-didecanoate (PDD) on VIP/PHM-27 gene expression in human neuroblastoma cells in culture were investigated. Bt2cAMP and phorbol esters increased the VIP/PHM-27 mRNA level by about 9- and 4-fold, respectively. In the presence of both Bt2cAMP and phorbol esters, the VIP/PHM-27 mRNA level increased by about 36-fold. The intracellular cAMP level was essentially unaffected by phorbol esters. The VIP/PHM-27 gene dosage was unchanged by Bt2cAMP and phorbol esters. The results suggest that cAMP and phorbol esters synergistically induce the VIP/PHM-27 gene expression through independent pathways.

1-Methyl-3-isobutylxanthine↗
PubMed1985

Effect of oxygen and superoxide anion on mutation rate in Ames test.

Effects of oxygen and superoxide anion to mutation rate were examined using the method of Ames. As test samples, 3-methylcholanthrene or 3,4-benzpyrene dissolved in squalene was used. In order to increase the concentration of dissolved oxygen in the medium during preincubation, oxygen was bubbled into the medium. Various combinations of xanthine oxidase, superoxide dismutase and hypoxanthine were used with an intent of changing the concentration of superoxide anion in the medium during the preincubation. An increase in the concentration of dissolved oxygen and superoxide anion resulted in a lower mutation rate, clearly showing the relationships of mutation rate with oxygen and with superoxide anion.

Animals↗
PubMed1984

The possible role of squalene and its peroxide of the sebum in the occurrence of sunburn and protection from the damage caused by U.V. irradiation.

To clarify the role of squalene peroxide in the occurrence of skin damage from sunburn, the optimum condition of squalene peroxidation and the effect of squalene peroxide on cutaneous tissue were examined. Peroxidation of squalene was more easily induced than palmitoleic acid and oleic acid in the unsaturated lipid occurred in sebum. The peroxidation of squalene gradually occurred by U.V. irradation, and it is parallel to increases in the malonyldialdehyde production (production of lipoperoxide). This peroxidation easily carries out in the case of high temperature (40 degrees C than 30 degrees C), and in the case of low pH. Good correspondence was recognized among the spectrum of natural daylight, U.V. absorption spectrum of squalene and erythema curve. Squalene and its peroxide have an important role in the occurrence of sunburn, and/or protection from damage caused by U.V. irradiation.

Animals↗
PubMed1984

Improvement of progressive systemic sclerosis (PSS) with estriol treatment.

Two female patients suffering from progressive systemic sclerosis (PSS) of generalized type were treated with estriol for 10 months. Although complete cure was not achieved, considerable beneficial effects were observed in these patients, but no serious side effects. Thus, skin softening was observed on all involved parts of these patients, which was accompanied by increased mobility of large or medium-sized joints and improved pigmentation and cyanotic redness on fingers and extremities. However, no apparent improvement of internal organ involvement could be detected. Histopathologically, a drastic reduction of homogenization of collagen bundles in the dermis of affected forearms was seen in these patients following estriol treatment. To our knowledge this is the first report of estriol therapy for PSS.

Collagen↗
PubMed1983

Silver stain for detecting 10-femtogram quantities of protein after polyacrylamide gel electrophoresis.

A rapid and highly sensitive silver stain and color stain were developed for visualizing proteins. The procedure is simple and the bands were clear. This silver stain detects 100 pg quantities of proteins. In order to stain quickly, sensitively, and sharply a protein matrix in a gel, the repeated shrinkage and swelling gel was developed with a hyper- and hypotonic solution to remove the sodium dodecyl sulfate (SDS) from SDS-protein complex and to generate influx of staining solution into the gel. We have found that the silver staining method with the repeated exposure to hyper- and hypotonic solution and a narrow well produced 10 fg order of proteins.

Electrophoresis, Polyacrylamide Gel↗
PubMed1983

ATP content in isolated mammalian nerve cells assayed by a modified luciferin-luciferase method.

ATP content in a nerve cell isolated from dorsal root ganglia of adult guinea-pigs by collagenase was measured by a newly developed technique modified from the conventional luciferin-luciferase methods. A small volume (4 microliters) of the nerve cell suspension, which contained 10-300 nerve cells (3-100 X 10(-4) microliters of cellular volume) under view of an inverted, phase-contrast microscope, was heat-treated for about 1 s by flame of an alcohol lamp. This heat-treated cell suspension was then reacted with a luciferin-luciferase solution. Light flux from the bioluminescence thus elicited gave an ATP content in single nerve cell, 27 pg (mean) +/- 10 pg (S.D.). ATP concentration in a nerve cell was calculated as 1.7 mM (mean) +/- 0.6 mM. The ATP content in a nerve cell was reduced when the nerve cells were exposed to KCN (5 microM) or dinitrophenol (20 microM), respectively.

Adenosine Triphosphate↗
PubMed1982

[Effects of intra-arterially administered capsaicinoids on vocalization in guinea pigs and medial thalamic neuronal activity in cats (author's transl)].

Algesic actions of capsaicinoids were investigated by utilizing vocalization in conscious guinea pigs and medial thalamic neuronal activity in gallamine triethiodide immobilized cats. Intra-arterial administration of capsaicin and dihydrocapsaicin evoked strong vocalization response, but other capsaicinoids, nordihydrocapsaicin, homodihydrocapsaicin, homocapsaicin, norcapsaicin, N-(4-hydroxy-3-methoxybenzyl)-6-methylheptamide, and N-(4-hydroxy-3-methoxybenzyl)-6-methylhept-trans-4-enamide, were weaker than capsaicin and dihydrocapsaicin. Similar results were obtained from medial thalamic nociceptive neurons in cats. Morphine (10 mg/kg s.c.) suppressed vocalization response evoked by intra-arterial administration of capsaicin and bradykinin. Aspirin (100 mg/kg i.p.) also suppressed the bradykinin-evoked response, but not the capsaicin-evoked response. Capsi-amide, a non-pungent substance of Capsicum annuum L., failed to suppress nociceptive response to capsaicin or bradykinin in guinea pigs and cats. Tachyphylaxis was elicited by repeated administration of capsaicin in vocalization. No cross-tachyphylaxis to bradykinin, acetylcholine, and dihydrocapsaicin could be observed.

Action Potentials↗