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Biomedical subjects

T Deguchi

Publications and source records attributed to T Deguchi.

At least 289 records · Page 16Linked to original sources
PubMed1984

Pathology of acute hepatitis A in humans. Comparison with acute hepatitis B.

Little is known about the pathologic characteristics of viral hepatitis A in humans. The authors compared the histologic features in liver biopsy specimens taken within 30 days of the onset of illness from 15 patients with hepatitis A and 14 patients with acute hepatitis B. In both hepatitis A and B, liver cell damage and necrosis were diffusely located, with accentuation in the centrilobular and midzonal areas in which ballooning degeneration and variation in cytoplasmic staining quality were observed frequently. One case of epidemic hepatitis A showed prominent periportal liver cell necrosis with inconspicuous centrilobular liver cell alterations. Kupffer cell mobilization was mild in hepatitis A, but more striking in hepatitis B. The portal inflammation was more pronounced and rich in plasma cells in hepatitis A than in hepatitis B. In summary, there were no major differences in the pathologic features of acute hepatitis A and B as sampled within 30 days of the onset of illness.

Acute Disease↗
PubMed1984

Increase of choline acetyltransferase by colchicine in primary cell cultures of spinal cord.

Colchicine (5-10 microM) increased choline acetyltransferase (ChAT) activity 5-10-fold and suppressed acetylcholinesterase (AChE) and glutamate decarboxylase (GAD) activities to 30% and 50%, respectively, of the levels of control cells in mouse spinal cord cells cultured for several days. The synthesis of radiolabeled acetylcholine (ACh) from [14C]choline was also enhanced 4.6-fold, although the uptake of [14C]choline into cells was decreased to 80% of control level. Neither the incorporation of [3H]leucine into protein nor the total amount of protein was increased by colchicine. Vinblastine also increased ChAT activity while cytochalasin B was not effective. Immunochemical titration study revealed that the increase of ChAT activity by colchicine was due to the accumulation of ChAT molecules. Co-culture of spinal cord cells with skeletal muscle markedly stimulated ChAT activity, and the addition of colchicine to the cocultures showed greater than additive effect. These observations indicate that colchicine increases ChAT molecules in a specific manner, that the stimulatory effect of colchicine on ChAT activity is possibly mediated via the interaction with microtubules, and that the increase of ChAT activity is based on a mechanism different from that of co-cultures with skeletal muscle cells.

Acetylcholinesterase↗
PubMed1984

[Feulgen-DNA cytofluorometry of the liver cell carcinomas].

Twenty-four autopsy cases of liver cell carcinomas were investigated by Feulgen-DNA cytofluorometry (NIKON SPM-RF 1-D) on paraffin-embedded tissue materials. The methods employed for tissue preparation and cytofluorometry were previously reported by us. The ploidy pattern based on cytofluorometry of the liver cell carcinomas exhibited wide DNA content distributions, in which many S phase cells having intermediate DNA content values ranging from diploid level to various, higher ploidy levels were included. From the comparative studies on both the histopathological findings and the ploidy pattern of the liver cell carcinomas, it was indicated that the peak value of the DNA content distribution was shifted from the diploid to the tetraploid level with the increasing appearance of the polyploid cells, and also that the degree of polyploidization appeared to correspond to the extent of the histological malignancy.

Adult↗
PubMed1984

[Cell kinetics and nuclear ploidy pattern in relation to the growth of gastric cancers as analyzed by DNA-RNA cytofluorometry].

We investigated the cell kinetics and nuclear ploidy pattern of human gastric cancers (12 early and 30 advanced cancers) using DNA-RNA cytofluorometry (NIKON SPM-RF1-D) with AO stain. The results showed that the gastric cancers studied could be divided into two main groups on the basis of ploidy pattern determined both by DNA and RNA contents: group I without, and group II with polyploidization. Cells having nuclear DNA contents between 2 n and 4 n were regarded as representing those in the S phase, and it was found that both groups had similar proliferative activity. In group I, cell proliferation without polyploidization seemed to be maintained during tumor growth regardless of the extent of invasion, and the fraction of 2 n cells was 72-94%, compared to 93-99% in control cells from the non-neoplastic gastric epithelium. In group II, however, the extent of polyploidization appeared to be increased in association with both the tumor growth and its invasion into deeper tissues; thus the fraction of 2 n cells was low, ranging from 12 to 79%. Especially, the fraction of 2 n cells in cancers with aneuploid-polyploidization was further decreased to 6-25%. Based on these results, it is hypothesized that, in the early stages of gastric cancers, the cell population may be composed mostly of diploid cells, but with both further tumor development and its invasion, the neoplastic cells may gradually differentiate into two distinct cell populations.

Adult↗
PubMed1984

Pharmacokinetics of human recombinant interferon-beta in monkeys and rabbits.

The pharmacokinetics of human recombinant interferon-beta ( ReIFN -beta) was compared with that of natural human interferon-beta (IFN-beta) in monkeys and rabbits after intravenous or intramuscular injection. After intravenous injection of 10(6) units/kg of ReIFN -beta or IFN-beta into monkeys or rabbits, serum levels of both interferons declined biexponentially. No significant differences between ReIFN -beta and IFN-beta were detected in most pharmacokinetic parameters including T1/2-beta, though T1/2-alpha of ReIFN -beta was significantly shorter than that of IFN-beta. These results seemed to be in conflict with the observed difference of stability of the interferons in vitro since ReIFN -beta was less stable than IFN-beta in monkey and rabbit serum. When ReIFN -beta (10(7) units/kg) was injected intramuscularly into monkeys or rabbits, it remained detectable in the serum for 24 hr; an absorption phase and an elimination phase were seen. However, AUC (the area under the serum concentration curve) after the intramuscular injection of ReIFN -beta was about one-half and one-third of that after the intravenous injection in monkeys and rabbits, respectively. ReIFN -beta and IFN-beta (10(6) units/kg) were both detectable in the serum after intramuscular injection into rabbits, but the level of ReIFN -beta was lower than that of IFN-beta. These results indicate that the lack of carbohydrate in ReIFN -beta did not essentially affect the in vivo pharmacokinetics in monkeys and rabbits after intravenous injection, but this was not the case after intramuscular injection.

Absorption↗
PubMed1984

[DNA-RNA cytofluorometry for a primary cancer of the stomach and choledochus].

We standardized DNA-RNA cytofluorometry with AO stain using a NIKON SPM-RFI-D instrument for cell smears. We applied this technique in a 72-year-old woman with primary double cancer of the stomach and choledochus. We first suspected malignancy of the choledochus and examined the desquamated cells in the bile cytofluorometrically to obtain by X-Y plotting the irregularly increased polyploid cells with a high percentage of cells in S phase. These polyploid cells and S phase cells were found to have an increased RNA content. Before operation, the presence of another malignancy of the stomach was also ascertained. The surgical specimens were diagnosed histopathologically as well differentiated, tubular adenocarcinoma of the stomach and moderately differentiated, tubular adenocarcinoma of the choledochus. By cytofluorometric analysis similar results were obtained, i.e., polyploidization with increase of S phase cells. Based on these results, we concluded that our method is useful for the diagnosis of alimentary tract malignancy, and that the criteria of malignancy appear to be unusual polyploidization with increased fractions of S phase cells.

Adenocarcinoma↗
PubMed1983

Immunochemical and immunohistochemical studies on the specificity of a monoclonal antibody to choline acetyltransferase of rat brain.

Choline acetyltransferase (ChAT) preparations partially purified from brains of rat, mouse and cat were electrophoresed in polyacrylamide gels and blotted on nitrocellulose sheets. A monoclonal antibody, Ab-57, bound specifically to one protein band which coincided with the peak of ChAT activity in each species. Using Ab-57, ChAT was demonstrated immunohistochemically in cholinergic structures in rat, mouse and cat brains. Thus, the specificity and cross-species reactivity of the monoclonal antibody Ab-57 have been established.

Animals↗
PubMed1983

Light and electron microscopic demonstration of guanylate cyclase in rat brain.

Guanylate cyclase (GTP pyrophosphate-lyase (cyclizing), EC4.6.1.2.) was histochemically demonstrated in rat brain with light and electron microscopes by using a specific monoclonal antibody to soluble guanylate cyclase from rat brain. Under a light microscope, intense reactions were seen in caudate-putamen complex, neocortex and cerebellar cortex. Immunoreactive cells were mainly some types of neurons such as small neurons in caudate-putamen complex, Purkinje cells in cerebellar cortex and pyramidal cells in neocortex. Some astroglial cells were also stained. Not all neurons or glial cells exhibited the positive guanylate cyclase reactivity. Electron microscopic examination revealed that guanylate cyclase was localized within postsynaptic components (perikaryon and dendrites) in neurons and in the cytoplasm and plasma membrane of astroglia. Presynaptic terminals were free of reaction. The observation supports a possibility that cyclic GMP is involved in the postsynaptic events of neuronal transmission and the regulation of intracellular processes.

Animals↗
PubMed1983

Monoclonal antibodies to choline acetyltransferase of rat brain.

Monoclonal antibodies to rat brain choline acetyltransferase were produced by the hybridoma technique. Two stable cell lines, Ab-57 and Ab-60, secreted immunoglobulin of subclass IgG1. The monoclonal antibodies bound to choline acetyltransferase without blocking catalytic activity. Affinity of Ab-57 was 100-times higher than that of Ab-60. Both antibodies bound to the rat enzyme in a mutually exclusive fashion. The antibodies showed cross-species reactivity with choline acetyltransferase from several mammalian brains.

Animals↗
PubMed1983

Phosphatidic acid mimics the muscarinic action of acetylcholine in cultured bovine chromaffin cells.

In cultured bovine chromaffin cells, acetylcholine as well as muscarine stimulated the 32Pi incorporation into phosphatidic acid, induced the efflux of 45Ca2+ from prelabelled cells, and, in parallel, elevated intracellular cyclic GMP content. Phosphatidic acid added to the medium also stimulated the efflux of 45Ca2+ and the synthesis of cyclic GMP in the cells in the same fashion as muscarinic agents, whereas it did not induce the secretion of catecholamines indicating that the effect of phosphatidic acid is specific to muscarinic action. The result supports the hypothesis that phosphatidic acid produced during phosphatidylinositol turnover is linked to the regulation mechanism of Ca2+ mobilization and cyclic GMP synthesis by muscarinic stimulation.

Acetylcholine↗