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Biomedical subjects

N Kamiya

Publications and source records attributed to N Kamiya.

At least 91 records · Page 5Linked to original sources
PubMed1988

Effect of lipophilic extract of Chlorella vulgaris on alimentary hyperlipidemia in cholesterol-fed rats.

The effect of glycolipid (GL) and phospholipid (PL) fractions obtained from Chlorella on serum lipid level and fecal excretion of steroids were examined in cholesterol-fed rats. The increase of the level of serum lipids were inhibited by the feeding of GL, PL and Chlorella powder almost the same degree. Fecal excretion of steroids (mostly of cholesterol, deoxycholic and lithocholic acid) were increased by feeding of GL and PL fractions. It is concluded that the feeding of each fraction inhibits the absorption of exogenous steroids and promotes turnover of bile acids in liver to suppress the increase of serum cholesterol level caused by administration of high cholesterol diet.

Animals↗
PubMed1987

Production of the alpha subunit of guanine nucleotide-binding protein GO by neuroendocrine tumors.

We have found that neuroendocrine tumors (including neuroblastoma, ganglioneuroma, gut carcinoid, pheochromocytoma, medullary thyroid carcinoma, insulinoma, glucagonoma, prolactinoma, carotid body tumor, and small cell lung carcinoma) produce considerable amounts (about 1000-80,000 ng/g tissue) of the alpha subunit of guanine nucleotide-binding protein, GO (GO alpha), whereas nonneuroendocrine tumors contain less than 300 ng of GO alpha/g tissue. GO alpha in the neuroendocrine tumors was present both in the soluble fraction, and cholate-extractable membrane-bound fraction of tissues. Immunoblots of membrane fractions of neuroblastoma and carcinoid tissues confirmed that the immunoreactive substance in the tumor tissues was GO alpha. Immunohistochemically, GO alpha was localized consistently in the cell membrane and occasionally in the cytoplasm of neuroendocrine tumors. GO alpha was also detected in sera of 73% patients with neuroblastoma at diagnosis, whereas serum GO alpha concentrations in control children, or patients with nonneuroendocrine tumors were lower than the detection limit of the immunoassay method employed. Serum GO alpha concentrations in patients with neuroblastoma changed with the clinical course; they fell in patients responding to treatment and increased in patients who relapsed. Since GO alpha, a specific protein in the neural and neuroendocrine cells, was found to be produced in considerable amounts by all types of neuroendocrine tumors but not in nonneuroendocrine tumors, GO alpha might be a useful biomarker for neuroendocrine tumors.

Adrenal Gland Neoplasms↗
PubMed1987

[Significance of tumor markers in the treatment of patients with ovarian malignancies].

Seven tumor markers (CA125, CA19-9, TPA, IAP, CEA, ferritin, LDH) were measured in 24 patients with ovarian cancer. The positive rates in untreated cases of ovarian cancer were 87.5% for CA125, 35.5% for CA19-9, 10% for CEA, 77.8% for IAP, 63.6% for TPA, 28.6% for LDH and 35.3% for ferritin. Among these, CA125 was the most available marker for detecting tumor growth or regression during each respective clinical course by serial measurement. Serial changes in serum alpha-fetoprotein (AFP) levels during treatment were studied among 27 patients with ovarian embryonal carcinoma. AFP decreased with a half-life of about 7 days, and was restored to the normal range within 10 weeks after the initial surgery and chemotherapy (VAC) in all cases. In subsequently fatal cases, AFP rose again during 10 to 30 weeks after the initial treatment.

Antigens, Neoplasm↗
PubMed1987

[An analysis of 117 cases of patients who died from tumor recurrence or from the progression of ovarian malignancies].

Out of 403 patients with ovarian with malignancies during 1978 to, 1985, 117 (29.0%) died from the progression of a non-curative cancer (56 cases, 47.9%) or from a cancer recurrence (61 cases, 52.1%). The mean survival rate 117 cases was 13.4 months, of which 103 (88.0%) cases concerned patients who died within 2 years and 114 (97.4%) who died within 3 years. A histological analysis revealed that patients with a serous or an endometrial cancer had a longer survival rate than others. Among 61 recurrent cases, 59 (96.7%) fell into recurrence within 2 years. Regarding the relationship between a recurrent of cancer and its prognosis, patients with a recurrence of an ascitic or a metastatic disease had a poorer prognosis than patients with a pelvic or an abdominal mass. An aggressive operation, such as a resection of a recurrent tumor, even if small in volume, led to a better prognostic result than no therapy.

Female↗
PubMed1986

Enhancing effect of thiabendazole on urinary bladder carcinogenesis induced by sodium o-phenylphenate in F344 rats.

Sodium o-phenylphenate (OPP-Na), a urinary bladder carcinogen in rats, and another fungicide, thiabendazole (TBZ) were fed separately or simultaneously to F344/DuCrj rats of both sexes. The rats were fed one of six diets, either the basal (control) diet or basal diet containing 0.2% TBZ (group T), 1% OPP-Na (1% SO), 2% OPP-Na (2% SO), 1% OPP-Na plus 0.2% TBZ (1% SO-T) or 2% OPP-Na plus 0.2% TBZ (2% SO-T) for 13 or 65 wk. In the 13-wk study, in which groups of ten rats of each sex were used, urinary bladder tumours appeared in 8/10 males in each of three groups--the 2% SO, 1% SO-T and 2% SO-T groups--but not in the remaining animals. Of these tumours, carcinoma accounted for 3/8 tumours in the 2% SO group, 2/8 in the 1% SO-T group and 8/8 in the 2% SO-T group. In the 65-wk study, in which groups of 15 rats were used, the tumour incidence in males was 1/15 in the T group and 15/15, 12/15 and 14/15 in the 2% SO, 1% SO-T and 2% SO-T groups, respectively, while in the females, tumours were found in 2/15, 1/15 and 12/15 animals in the 2% SO, 1% SO-T and 2% SO-T groups, respectively. Of these tumours, carcinoma accounted for 10/15, 11/12 and 10/14 in the males of the 2% SO, 1% SO-T and 2% SO-T groups, respectively, and for 1/2 and 6/12 in the 2% SO and 2% SO-T females, respectively. The tumour incidences in the 1% SO-T males in the two studies and in the 2% SO-T females in the 65-wk study showed a statistically significant increase over those in the 1% SO males or the 2% SO females. Thus, TBZ apparently enhanced the carcinogenic effects of OPP-Na in the rat urinary bladder.

Animals↗
PubMed1986

[Serum CA125 in malignant ovarian tumor--periodical monitoring and correlation with other tumor markers].

CA125 is a new unique tumor marker for epithelial ovarian cancer, and its clinical use has recently increased considerably. We have periodically monitored 14 cases of ovarian cancer (7 cases of serous cystadenocarcinoma, 4 cases of clear cell carcinoma, 1 case of endometrioid carcinoma and 1 case of metastatic ovarian cancer) using CA125, before and after surgery, during chemotherapy, and in follow-up. The serum CA125 was measured with a radioimmunoassay kit. As a result of this monitoring, we have discovered the following facts: The ten cases in which the titer of CA125 dropped to 35U/ml, which is cut off, by 60 days after surgery, when we had finished 2 courses of chemotherapy, showed good progress. In contrast to this, in the other cases, the degree of CA125 was still high 60 days after the surgery and did not drop after that. In these 4 cases, the tumor growth was found. It was therefore concluded that with this method a prognosis could be made much earlier than with the current system, and that relapse could be detected far earlier. We have also examined the mutual relations between CA125 and other tumor markers, IAP, TPA, HBDH, CEA, Ferritin, alpha 1AT, ESR, and LDH. Although we could see some usefulness in periodic monitoring with IAP, unlike CA125 it did not reflect the condition of a disease. The coefficients of correlations between CA125 and other tumor markers are as follows: IAP 0.5268, TPA 0.4541, HBDH 0.4551, CEA 0.2942, Ferritin -0.1005, alpha 1AT 0.5321, ESR -0.0619, LDH 0.5994.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMed1984

X-ray diffraction photographs of chicken gizzard G-actin.DNase I complex crystals taken with synchrotron radiation.

X-ray diffraction photographs of a chicken gizzard G-actin.DNase I complex crystal have been recorded using the synchrotron radiation beam emitted by the Synchrotron Radiation Source at Daresbury and the Photon Factory at Tsukuba. The resolution limit was extended to 2.4 A and the exposure time was reduced approximately by a factor of 10, when data recorded at the Photon Factory, were compared with those recorded with a conventional rotating-anode source. Using a newly designed Weissenberg camera equipped with a multi-layer line screen, the diffraction data in a 36 degrees oscillation range were recorded on a single film up to 3.5 A resolution.

Actins↗
PubMed1984

ATP- and calcium-controlled contraction in a saponin model of Physarum polycephalum.

Saponin models of the plasmodial strand of Physarum polycephalum were constructed to study how Ca2+ and ATP regulate the generation of tension. ATP-induced isometric tension in a saponin model increased with an increase in ATP concentration until maximum tension (0.3-1.7 mg) was reached at about 1 mM. The sensitivity of the model to ATP was heightened three to five times in a basic solution containing an ATP-regenerating system, the maximum tension (0.3-0.6 mg) being reached at 0.2 to 0.3 mM ATP. Contraction of the model also depended on the Ca2+ concentration irrespective of the presence or absence of the ATP-regenerating system. The optimal pCa was 7.0, and tension decreased with a Ca2+ concentration above or below this value. These results indicate that the tension generated in the plasmodial strand of Physarum in vivo may be regulated by ATP and/or Ca2+.

Adenosine Triphosphate↗
PubMed1983

Crystallographic studies of the chicken gizzard G-actin X DNase I complex at 5A resolution.

The structure of the chicken gizzard G-actin X DNase I complex has been determined at 5 A resolution by an X-ray diffraction method. Protein phases were computed by the multiple isomorphous replacement method using four heavy atom derivatives. The mean figure of merit was 0.65. Dimensions of the three molecular species, the complex, G-actin and DNase I, were determined based on the "cypress wood" models derived from the electron density map. The natures of the heavy atom binding sites are discussed in relation to the distinction between the two component molecules. The pattern of successive contacts between actin molecules observed in the present crystal seems unrelated to that found in F-actin.

Actins↗
PubMed1982

[Calcium ions in the steroidogenic action of HCG].

Extensive studies have recently been conducted on the expression of hormone actions, especially on its mechanisms. Sutherland, et al. identified the function of C-AMP as an intracellular messenger of peptide hormones. Recent studies by several investigators including ours have concluded that the role of C-GMP and calcium are as important as that of C-AMP. In this report we present out findings on the role of Ca ions in the acceleration of steroid production in isolated porcine cells of the corpora lutea. (1) The incubation time needed to compare the production of progesterone and that of C-AMP is at least 120 mins. (2) Production rates of both C-AMP and progesterone in the presence of HCG were maximum at 10(-7) g/ml HCG. Inclusion of Ca ions in the medium increases this production rate. (3) When Ca ions are included in the medium, the accelerated rate of progesterone production takes on its highest value at 1.2mM Ca. (4) Verapamil and cycloheximide inhibit the production of progesterone. (5) The binding capacity of 125I-HCG combined with corpora lutea cells is independent of the Ca concentration in the medium. (6) Ca uptake into corpora lutea cells increases according to the concentration of HCG until it reaches a plateau at 10(-7) g/ml HCG. This acceleration by HCG is affected by Ca and is remarkably inhibited by verapamil. These results indicate the important role of Ca ions in the acceleration of progesterone production compared to that of C-AMP.

Animals↗
PubMed1981

Simultaneous oscillations of Ca2+ efflux and tension generation in the permealized plasmodial strand of Physarum.

Calcium is now generally thought to play a key role in regulating a variety of cellular movements. When the plasmodium of Physarum polycephalum was treated with the calcium-ionophore A23187 or the quasi-ionophore amphotericin B, Ca2+ leaked out. Ca2+ efflux into the ambient solution from the plasmodial strand segment was measured by the luminescence of a photoprotein aequorin, and the tensile force production was recorded simultaneously. Ca2+ efflux oscillated with the same period as the cycle of tension generation in the strand, but the phase of cyclic changes in Ca2+ efflux was opposite to that of tension generation. That is, Ca2+ efflux fell in the increasing tension phase and rose in the decreasing tension phase. Cyclic changes in efflux of Ca2+ are provisionally interpreted as reflecting corresponding changes in concentrations of free Ca2+ in the cytoplasm.

Calcimycin↗
PubMed1980

Tension generation by actomyosin thread from a non-muscle system.

A suitable motility model reconstituted from non-muscle contractile proteins should offer a powerful tool for analysing the molecular events in cell motility. Actomyosin thread has been thought to be such a model. As far as non-muscle motile systems are concerned, however, only a very limited number of experiments have been done in this direction. No direct measurement of the tension produced by non-muscular actomyosin thread has been reported in spite of its importance for quantitative studies. We now report that a segment of actomyosin thread of Physarum polycephalum can generate a considerable amount of tension, which is a function of the micromolar concentration of ATP. The maximum isometric tension was a high as 10 g cm-2 at 10 microM ATP.

Actomyosin↗