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Biomedical subjects

K Nakanishi

Publications and source records attributed to K Nakanishi.

At least 19 recordsLinked to original sources

Benzo(a)pyrene-7,8-dihydrodiol 9,10-oxide adenosine and deoxyadenosine adducts: structure and stereochemistry.

The structure and absolute stereoconfigurations of four adenosine adducts with (+/-)-7 alpha,8 beta-dihydroxy-9 beta, 10 beta-epoxy-7,8,9,10-tetrahydrobenzo(a)pyrene (BPDE) and their deoxyadenosine analogs have been determined. They result from both cis and trans addition of the N6 amino group of ademine to the 10 position of both enantiomers of BDPE. This was determined from studies of the nuclear magnetic resonance spectra, mass spectra, and circular dichroism spectra, as well as from their pKa values and chemical reactivities.

Benzopyrenes

Quantification of nuclear DNA and intracellular glycogen in a single cell by fluorescent double-staining.

It was found that intracellular glycogen is stabilized against acid treatment when it is stored under dry conditions for three months after methanol fixation. This stabilization allowed quantitative double fluorescence staining for nuclear DNA and intracellular glycogen, in a single cell. A Feulgen nucleal reaction, with acriflavine-Schiff's reagent following 5 N HCl hydrolysis at 25 degrees C for 4 min, was followed by a pararosanilin-Schiff PAS reaction for glycogen. This short term hydrolysis was found to be sufficient for the performance of a acriflavine-Schiff's Feulgen nucleal reaction and to provide good preservation of intracellular glycogen. Quantification of nuclear DNA and intracellular glycogen were consecutively carried out with a digital microfluorometer on a single ascites cancer cell of the AH-13 line stained by this method. It was found that there is a positive linear correlation between the amount of DNA and glycogen in this cell line.

Animals

Combined protein and DNA measurements by the ninhydrin-Schiff and Feulgen techniques.

Feulgen nuclear staining with pararosanilin-SO2 was combined with the ninhydrin-Schiff technique. The aldehyde groups converted from primary amino groups are stained with an acriflavine-Schiff reaction. This results in a red nuclear fluorescence and a bright yellow cytoplasmic and nuclear fluorescence. The combined fluorescence staining facilitates cytofluorometric determination of total protein and DNA in the same cell. The ninhydrin-Schiff reaction is affected by the fixation procedure and the duration of the ninhydrin reaction. Investigations with a model system showed that proportionality between the fluorescence intensity of acriflavine and the amount of protein stained by the procedure was obtained after fixation with a fixation mixture suggested by Böhm et al. (1968) and a reaction with ninhydrin at 37 degrees C for 10 h. The ninhydrin-Schiff reaction has no effect on the fluorescence intensity of cells previously treated with pararosanilin-Feulgen staining and it is not affected itself by this previous procedure. Testing this double fluorescence staining on cytology specimens taken from patients with gastric carcinoma and uterine cervial carcinoma, cancer cells were shown to have markedly increased protein and DNA contents compared with those of normal cells.

Adult

Age associated increase of single-stranded regions in the DNA of mouse brain and liver cells.

The touch smears of brain cells and hepatocytes of young and senescent mice were stained with antibody to cytidine nucleoside by an indirect immunofluorescence technique and subsequently combined with fluorescence cresyl violet staining of DNA. Nuclear binding of the antibody which reacts only with denatured or single-stranded regions in the DNA was seen only in the tissues of an aging animal. No such DNA lesion was detected in the epithelial cells of the gastrointestinal tract at any age. This type of DNA alteration is supposed to accumulate in the slowly renewing and non-replenishing tissues as a function of aging. The antibody was found not to react with the cells in S phase as demonstrated by 3H-thymidine autoradiography on a smear of newborn hepatocytes after the double fluorescence staining with cresyl violet and anti-cytidine antibody.

Aging

Nystagmic responses of hippocampal origin in normal rabbits.

Nystagmic responses in intact, healthy rabbits given hippocampal stimulation were studied and the following results were obtained. Two types of mystagmic responses were derived from the hippocampus. 1) One was a horizontal nystagmic response with a middle amplitude and was directed to the right and the left. This type of nystagmic response was first induced in the 'pre- and post-stimulus' phase after repeated electric stimulation of the hippocampus and was found in almost every rabbit examined. Furthermore, there was a positive correlation between the development of nystagmic response and repetition of the stimulation. 2) The other was a horizontal nystagmic response with a small amplitude directed toward the side of the stimulation. This type of nystagmic response was induced in the 'during-stimulus' phase and was found in two rabbits. There was no positive correlation between development of nystagmic response of this type and repetition of the stimulation.

Animals

Enhancing effect of inducers of liver microsomal enzymes on induction of hyperplastic liver nodules by N-2-fluorenylacetamide in rats.

The effects of inducers of liver microsomal enzymes on the induction of hyperplastic liver nodules by N-2-fluorenylacetamide (2-FAA) were studied in male F344 rats. The rats were fed a diet containing 200 ppm 2-FAA for 2 weeks and then given test chemicals for the following 8 weeks. Partial hepatectomies were performed at the end of the third week of the experiment. The compounds were tested, and their concentrations (in ppm) in the diet were as follows: 1,000 polychlorinated biphenyls (PCB), 500 PCB, 500 PCB plus 70 3-methylcholanthrene (MCA); 500 PCB plus 500 phenobarbital, 70 MCA, 500 phenobarbital, 500 phenobarbital plus 500 beta-naphthoflavone, and 2,500 3-(3,5-dichlorophenyl)-5,5-dimethyloxazoline-dione-2,4 (DDOD). All experimental groups developed significantly greater numbers and total areas of hyperplastic nodules than did the controls. In groups treated similarly with the test chemicals but without partial hepatectomy, the numbers and total areas of hyperplastic nodules were significantly less than those in the experimental groups with partial hepatectomy. Administration of test chemicals except 2-FAA to partially hepatectomized rats did not induce hyperplastic nodules. The present results showed the early detection of the enhancing effect on induction of hyperplastic liver nodules by a system consisting of the following three procedures: 1) 2-FAA feeding; 2) administration of test chemicals, and 3) partial hepatectomy during administration of test chemicals. In this system DDOD enhanced the induction of hyperplastic nodules of the liver.

2-Acetylaminofluorene

Regulation of antibody response in different immunoglobulin classes. VI. Selective suppression of IgE response by administration of antigen-conjugated muramylpeptides.

The suppressive effect of antigen-conjugated muramylpeptides or 6-O-mycoloyl muramylpeptides selectively on the induction of IgE antibody response was demonstrated. Preadministration of DNP-mycoloyl muramylpeptides completely inhibited the induction of the anti-DNP IgE antibody response with DNP-ovalbumin (DNP-OA). The selective suppression of the IgE response was due to the induction of DNP-specific suppressor T cells by DNP-mycoloyl muramylpeptides, and the suppressor cells were shown to be radiosensitive. Preadministration of OA-conjugated muramylpeptides partially inhibited the primary and secondary induction of an anti-OA IgE antibody response. The suppressor effect was also due to the induction of OA-specific suppressor T cells. Application of allergen-conjugated muramylpeptides as therapeutic agents in human allergic diseases was suggested.

Acetylmuramyl-Alanyl-Isoglutamine

Long-term experiment of maximal non-carcinogenic dose of dimethylnitrosamine for carcinogenesis in rats.

Studies were made on the maximal non-carcinogenic dose of dimethylnitrosamine (DMN) in rats. Groups of Wistar strain rats of both sexes, 6 weeks old, were given standard diet without DMN (group 1), or containing 0.1 ppm DMN (group 2), 1.0 ppm DMN (group 3), or 10 ppm DMN (group 4) for 96 weeks and then sacrificed for hematological, serum-biochemical, and histopathological examinations. After 96 weeks, the weights of the body and main organs in the different groups were not significantly different. The leucocyte count and blood urea-nitrogen (BUN) in group 4 were slightly increased, but other serum findings were not significantly different in different groups. Hepatocellular carcinomas were found in group 3 (1 male and 3 females), but not in group 2. Hemangioendotheliomas of the liver, adrenal adenomas, pituitary adenomas, interstitial cell tumors of the testis, ovarian tumors, and leukemia were also found. Pyelonephritis was found in both experimental and control animals, but no kidney tumors developed with these dose levels of DMN. These results show that on long-term oral administration to rats, 1.0 ppm DMN is the minimum carcinogenic dose, while a level of about 0.1 ppm DMN is non-carcinogenic.

Animals

[Treatment with NK 631 (new bleomycin analog) of oral and maxillofacial cancer (author's transl)].

Eight cases of malignant tumors of the head and neck were treated with NK 631 on a dosage schedule of 10 mg at a time 3 times weekly, by intravenous one-shot injection or intravenous drip infusion, to observe its therapeutic effects and adverse reactions. The treatment was assessed markedly effective in 3, moderately effective in 1 and ineffective in 4 of them. The treatment was also assessed moderately or markedly effective in 3 and ineffective in 2 out of squamous cell carcinoma cases. Hematologic findings, serum electrolytes and enzymologic findings were normal, but the pulmonary function examinations revealed a tendency for PaO2 to decrease slightly. In 1 case where frequent cough was observed, the cough was mitigated on withdrawal of the treatment. The adverse reactions that evolved included fever, alopecia, eruptions, nausea and vomiting, and pigmentation of the nail. To summarize these findings, the authors were impressed with NK 631 and that the agent would exert an excellent antitumor effect, compared with bleomycin, and that its effect would evolve at the early stage of its treatment. Fixed drug eruption was observed as an adverse reaction of this drug in 1 case; however, the adverse reactions of this bleomycin analog appear similar to those of its parent compound, bleomycin.

Adenocarcinoma

Sequential quantitative studies on hyperplastic nodules in the liver of rats treated with carcinogenic chemicals.

Sequential quantitative analyses were made of hyperplastic liver nodules induced by treating male Fischer rats first with diethylnitrosamine (DEN) and then with N-(2-fluorenyl)acetamide (2-FAA), alpha-isomer of 1,2-3,4,5,6-hexachlorocyclohexane (alpha-BHC), or phenobarbital. The test rats were injected ip with 200 mg/kg body weight of DEN, given basal diet containing 2-FAA, alpha-BHC, or phenobarbital from week 2 to 12, and subjected to partial hepatectomy at the end of week 3. From week 6, significantly higher percentage areas of hyperplastic nodules per unit area of liver were found in all experimental groups than in the control group. From week 8, significantly more hyperplastic nodules were found in all experimental groups than in the control group. Continuous administration of alpha-BHC or phenobarbital for 12 weeks with partial hepatectomy did not induce hyperplastic nodules. Continuous administration of 2-FAA did induce hyperplastic nodules, but the percentage areas and number of these nodules were significantly lower than in rats injected with DEN and then given 2-FAA orally, with partial hepatectomy.

2-Acetylaminofluorene