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Biomedical subjects

N Akamatsu

Publications and source records attributed to N Akamatsu.

At least 91 records · Page 5Linked to original sources
PubMed1989

[Experimental study on vascularized fresh whole-joint allograft transplantation].

The vascularization of fresh whole knee and hip joints was done as part of an allograft transplant procedure involving forty rats (12 weeks old). Cyclosporin and prednisolone were injected into thirty-five recipient rats; five rats did not receive any drugs and were used as the control group. All control group rats with necrotic limbs died two to three weeks after the operation. Eleven of the twenty rats with transplanted knee joints and ten of the fifteen rats with transplanted hip joints began walking with full weight-bearing and the transplanted joints exhibited good mobility one month after the operation. Autopsy findings four, eight and sixteen weeks after the operation showed no degenerative or necrotic changes of the articular cartilage or subchondral bone of the joints. We concluded that this technique of vascularized whole-joint transplantation in rats was successful. This may be clinically applicable to reconstructive surgery after resection of diseased joints.

Anastomosis, Surgical↗
PubMed1988

Increased formation of unintegrated viral DNA in skin fibroblasts from patients with familial polyposis coli shortly after infection with Kirsten murine sarcoma virus.

Skin fibroblasts from patients with familial polyposis coli (FPC) exhibit increased frequency of morphological transformation, anchorage-independent growth, and enhanced production of viral RNA and viral particles after infection with murine sarcoma virus(murine leukemia virus), MSV(MLV). These FPC fibroblasts form greater amounts of unintegrated viral DNA as compared to normal fibroblasts during the first 4 to 24 hr after infection with Kirsten MSV(KiMLV), suggesting that increased susceptibility of FPC cells to MSV is determined at an early stage of viral transformation. Several MSV-transformed clones of both FPC and normal fibroblasts, isolated from agarose gel, were non-producers having integrated viral genome which was expressed into viral RNA and rescued by infection with MLV.

Adenomatous Polyposis Coli↗
PubMed1988

Postnatal changes in N-linked oligosaccharides of glycoproteins in rat liver.

[3H]Mannose-labelled glycopeptides in the slices of livers from neonatal and 1-, 2-, 3- and 5-week-old rats were characterized by column chromatographies on Sephadex G-50 and concanavalin A-Sepharose and by endo-beta-N-acetylglucosaminidase H digestion. The proportion of complex-type glycopeptides was increased with time until 2 weeks post partum and then returned to the neonatal level. This was mainly due to the increased proportion of concanavalin A-bound (biantennary) species. These changes were accompanied by consistent changes in the activities of processing enzymes in liver microsomal fraction, especially of N-acetylglucosaminyltransferase I. Complex-type glycopeptides from neonatal and 2- and 5-week-old rat livers were further characterized by column chromatographies on Bio-Gel P-6 and DE 52 DEAE-cellulose in combination with neuraminidase digestion. No significant difference was found between concanavalin A-bound species from neonatal liver and those from liver 5 weeks post partum, most of which were sialylated. Concanavalin A-bound species 2 weeks post partum were comparatively smaller in size and less sialylated. On the other hand, there was no significant difference among concanavalin A-unbound species from the three different sources, most of which were sialylated. Since glycoproteins from regenerating rat liver also contain a higher proportion of complex-type oligosaccharides, as previously reported, such changes in N-linked oligosaccharides of glycoproteins may be related to control of the growth of liver cells.

Animals↗
PubMed1988

Chemical and viral transformation of cultured skin fibroblasts from patients with familial polyposis coli.

Treatment of skin fibroblasts from an FPC patient with 4NQO or MNNG followed by sequential passaging caused morphological changes of the cells, which showed characteristics of transformed cells such as a high frequency of colony formation in agarose, increased growth ability, and chromosomal abnormalities. This and other fibroblast lines from 5 of 12 FPC patients had an increased susceptibility to 4NQO cytotoxicity, which was caused by enhanced 4NQO-reductase activity rather than by reduced DNA repair. However, the susceptibility to cytotoxicity of MNNG and repair of MNNG-damaged DNA were normal in FPC cells. The tumor promoters TPA and DHTB enhanced the frequency of chemical transformation of the FPC fibroblasts, and protease inhibitors suppressed the promoter-enhanced transformation. The skin fibroblasts from many FPC patients exhibited increased susceptibility to transformation by murine sarcoma viruses. Analysis of the viral DNA and RNA after infection revealed that the increased susceptibility is determined at an early stage of transformation. Two out of 5 MNNG-transformed clones of FPC fibroblasts, isolated from agarose, had increased expression of c-Ki-ras or c-Ha-ras, and 4 of 4 MSV-transformed clones showed high expression of viral Ki-ras. These clones grew further after isolation from agarose, but were mortal and did not form tumors in nude mice. The present results suggest that additional changes in morphologically transformed FPC fibroblasts are required for malignant transformation.

4-Nitroquinoline-1-oxide↗
PubMed1988

[Ultrasonically guided puncture of endometrial cysts--aspiration of contents and infusion of ethanol].

Ultrasonically guided transvaginal or transabdominal puncture of an endometrial cyst with a transvaginal or transabdominal sector probe was done safely and correctly. In 7 endometrial cysts in 5 patients, we aspirated the contents, flushed with saline solution and cleaned the interior cysts. At last 99.9% ethanol was infused into 6 cysts for 30 minutes. In all cases puncture of the endometrial cyst was successful and the contents of the endometrial cyst were collected. There were no major side effect and no recurrence of endometrial cyst. It was proven that the aspiration of contents and infusion of ethanol were superior methods for treating endometrial cysts.

Adult↗
PubMed1988

RI lymphography by submucous injection in the pars vaginalis of the cervix uteri.

We have improved conventional RI lymphography, and investigated its usefulness as a screening method for lymph node metastasis. We injected 99mTc-sulfur colloid directly under the mucous membrane of the pars vaginalis of the cervix uteri of patients with cervical cancer, and took images every 5 minutes for 2 hours. At the same time, we analyzed the data stored in a computer, and attempted to observe the movement of radioisotopes taken into the lymph nodes. The subjects were 100 patients (200 study units) with cervical cancer, on whom histological examinations were performed. Of these, 41 study units were seen to be clouded by invasive cancer in the lymph nodes or parametrium. In the group in which both lymph nodes adjacent to the uterine cervix and the common iliac lymph nodes were delineated, lymph node metastasis was ruled out in 96.2%. Also, in some of the cases in which metastasis was seen, even though the lymph nodes were delineated, there was some delay in taking up the isotope. Therefore, it seems that as the main method, a diagnosis of "true negative" in the case of no metastasis is more useful than a "true positive" for the existence of metastasis.

Cervix Uteri↗
PubMed1987

Use of transrectal radial scan ultrasonography in evaluating the extent of uterine cervical cancer.

Transrectal radial scan ultrasonography has been performed in 180 cases of stage Ib, IIa, or IIb uterine cervical cancer. Increases in the parametrial length, width, their product, and internal echo intensity as well as shift of the cervix to the side of more severe induration have been demonstrated, irrespective of the presence or absence of menstruation, as the clinical infiltration becomes more severe. Furthermore, concerning the presence or absence of histologic infiltration, there is a very strong possibility of a cancerous infiltration in cases of mass formation in the parametrium.

Adult↗
PubMed1987

Effects of chronic propranolol treatment on hepatic adenylate cyclase system in the rat.

The biochemical aspects of hepatic beta-adrenergic receptors and adenylate cyclase activity in male adult rats were examined during chronic treatment of a beta-adrenergic antagonist, propranolol. The blockade of beta-adrenergic nervous systems for 7 to 10 days produced a considerable elevation of basal, glucagon, sodium fluoride, and 5'-guanylylimidodiphosphate, Gpp (NH)p-stimulated enzyme activity with a negligible response to a beta-adrenergic agonist, isoproterenol. There was no alteration in the density or the affinity of beta-adrenergic receptors for the agonist during the treatment. Guanine nucleotides have failed to induce a transformation of the higher affinity to the lower affinity state of beta-adrenergic receptors of the hepatic membrane derived either from control or the propranolol-treated animals. The activity of stimulatory guanine nucleotide regulatory proteins (Ns) in the enzyme, assessed by ADP-ribosylation was also not altered by the antagonist. These results suggest that the mechanism of the observed sensitization of adenylate cyclase induced by chronic beta-adrenergic blockade involves facilitation of Ns interaction with the catalytic subunit of the enzyme with no change in the beta-adrenergic receptor functions.

Adenosine Diphosphate↗
PubMed1986

[A population survey on mass screening program for gastric cancer. Part 2. Why don't they receive mass screening examination?].

The attitude of non-examined residents to a mass screening program for gastric cancer has been surveyed by a self-administered questionnaire among 3660 residents in a small town near Kitakyushu City. Among 1159 subjects who had not received any type of examination during the past 3 years, the answers of 638 subjects who completed the questionnaire were analyzed in this study. Reasons for not being examined were classified into 4 types; "unnecessary", "rejected", "inconvenient" and "others". The most frequent reason for not taking part in the screening program was "inconvenient" which means that there were some difficulties for them to participate in the program even if they wanted to. This reason was followed by "unnecessary" and "rejected". "Inconvenient" was the main reason for not being examined among people in their forties and fifties and/or among those who have jobs. Among elderly people, "unnecessary" had the highest frequency. "Rejected" was the least important reason in all age groups. In each age group "rejected" was found more frequently among females than males. As the type of reason for not being examined was different among groups, it is essential to work out different countermeasures for each group in order to raise the participating rate.

Adult↗
PubMed1986

[A population survey on a mass screening program for gastric cancer. 1. Population characteristics related to examination rates for the screening program].

The types of examination received for gastric cancer during the past 3 years have been surveyed by a self-administered questionnaire among residents of a small town near Kitakyushu City. Among 3660 surveyed, 2205 subjects who completed the questionnaire are analyzed in this study. Examination rates of mass screening for males were higher than those for females. Males in their forties and fifties and females in their forties through sixties have higher examination rates than other age groups. Higher examination rates were seen in public officials and employees who have opportunities to receive the screening program at work site. On the other hand, among people without a job and housewives who have opportunities to receive a screening program offered only by the town hall, examination rates of the mass screening program were low. More people with a family history of cancer death were examined than those without a similar family history. There was no difference in the examination rates by the mass screening program between the people who took care of their health and those who did not. In order to raise examination rates for the mass screening program, it is essential to improve the systems of this program which can be easily accepted, and to educate residents in order to stimulate motivation for screening.

Adult↗
PubMed1986

An intrinsic mechanism for the oscillatory contraction of muscle.

A new model based on the theory of dynamical systems is proposed for the intrinsic random or systems is proposed for the intrinsic random or pseudo-random mechanism underlying certain types of muscular tremor. The active length-tension curve of the individual sarcomere, in conjunction with the passive length-tension relation is a map from length to tension with an observed time delay between length change and resulting tension change. The passive length tension relation is assumed to instantaneously relate this tension change back to a change in length. The stability properties of this iterated interval map are investigated by means of computer simulation and computation of the Lyapunov exponent and the bifurcation tree. The resulting analysis is related to experimental tremor data in the literature in terms of period doubling, bifurcation points, and "chaotic" behavior. The model appears to have its most fruitful application in understanding the insect type and isometric mammalian types of tremor.

Animals↗
PubMed1986

Glucosamine 6-phosphate acetylase in rat ascites hepatomas.

The fetal type enzyme pattern of glucosamine 6-phosphate acetylase (glucosamine-phosphate acetyltransferase, EC 2.3.1.4) was present in rat ascites hepatomas. The levels of acid-soluble and protein-bound amino sugars in the hepatomas were determined.

Acetyltransferases↗
PubMed1986

alpha-Dihydrodecaprenyl phosphate as a sugar carrier in the membrane of AH 70Btc hepatoma cells.

The effect of alpha-dihydrodecaprenyl phosphate, dolichyl phosphate and solanesyl phosphate on the lipid intermediate pathway for protein glycosylation was studied with crude membrane fraction prepared from AH 70Btc hepatoma cells. alpha-Dihydrodecaprenyl phosphate increased the incorporations of [14C]mannose from GDP-[14C]mannose into CHCl3-CH3OH (2:1, v/v) extract, oligosaccharide-lipid and proteins. The above and the other data showed that alpha-dihydrodecaprenyl phosphate may function as a mannose carrier in the lipid intermediate pathway.

Animals↗
PubMed1985

Alterations in fucosyl oligosaccharides of glycoproteins during rat liver regeneration.

[3H]Fucose-labelled glycopeptides in the slices of liver 24h after partial hepatectomy were fractionated on Sephadex G-50. Glycopeptides from regenerating liver contained a higher proportion of lower-Mr components than did controls. Regenerating liver contained a higher proportion of glycopeptides that were bound to concanavalin A-Sepharose and were subsequently eluted with 20mM-methyl alpha-D-glucopyranoside than did controls. Concanavalin A-bound glycopeptides from each source were entirely bound to a lentil lectin-Sepharose column. Both the concanavalin A-bound and -unbound fractions from regenerating liver were indistinguishable from the respective controls by Bio-Gel P6 column chromatography and neuraminidase digestion. These results show that fucosyl glycopeptides from regenerating liver contain a higher proportion of biantennary species with core fucose residues than do controls. Glycopeptides from regenerating livers 12h, 72h and 144h after partial hepatectomy were also examined; however, the difference was not significant. These observations suggest that the alterations in fucosyl glycopeptides may be related to rapid growth of hepatocytes 24h after partial hepatectomy. No significant difference was found in either [3H]mannose- or [3H]fucose-labelled glycoproteins from regenerating liver and from controls by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, suggesting that the alteration in glycopeptides should depend on some differences in the late stage of oligosaccharide processing.

Animals↗