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Biomedical subjects

K Ohyama

Publications and source records attributed to K Ohyama.

At least 199 records · Page 11Linked to original sources
PubMed1985

[The establishment of the assay-system of blood adrenal steroids in the method of gaschromatograph/mass spectrometry (GC/MS)].

In this study, we established a method for the quantitative measurement of native adrenal steroids with GC-MS equipped with capillary column (cross-linked methyl silicone 25 m X 0.2 mm I.D., 0.11 m thin film). 1 ml of serum sample containing 5 alpha-cholestane as internal standard (IS) was elicited by organic solvent using extrelunt column. These samples were derived by n-butylboronic acid, o-methylhydroxylamine and trimethyl-silylating agents, then were finally applied to GC-MS. The intensities of molecular ions were used for the measurement of the serum concentration of steroids. The molecular ion peaks of steroids were obtained at m/z460 (17 alpha-hydroxyprogesterone; 17OHP), m/z548 (corticosterone; B), m/z470 (11-deoxycortisol; S), m/z417 (pregnenolone; PL), m/z372 (progesterone; PT), m/z558 (cortisol; F), m/z389 (dehydroepiandrosterone; DHEA), m/z371 (estrone; E1), m/z416 (estradiol; E2), m/z504 (estriol; E3), m/z389 (testosterone; T), m/z344 (androstenedione; A) and m/z372 (IS). The curve of calibration for each steroid showed good linearity. The sensitivities of the GC/MS method were less than 5pg/one shot of each sample. The coefficients of variations of accuracies and precisions in this GC/MS method were less than 15% of each steroid. The samples from normal subjects after metyrapone and ACTH loading tests, and the patients of congenital adrenal hyperplasia showed a good correlationship between the data of GC/MS and the data of RIA after sephadex LH-20 column-chromatography. These results implied the usefulness of our system in clinical application. Moreover, this assay takes only 3 hrs. Thus it saves much time in comparison with the time-consuming radioimmunoassay system.

Adrenal Cortex Hormones↗
PubMed1985

Enzyme immunoassay for elcatonin, a synthetic analogue of eel calcitonin, in plasma.

An enzyme immunoassay for the direct measurement of elcatonin, a synthetic analogue of eel calcitonin with hypocalcemic activity, in rat and dog plasma was developed. Elcatonin was conjugated to beta-galactosidase using an N-succinimidyl ester, and the product was used as the tracer. The antibody-bound tracer was precipitated using a second antibody. The nonequilibrated procedure gave better sensitivity and precision than the equilibrated procedure. The nonequilibrated method was sensitive at quantifiable concentrations as low as 0.2 ng/mL using 0.1 mL of plasma and was also reproducible, with RSD values generally less than +/- 10%. Plasma levels in rats and dogs were determined by this competitive enzyme immunoassay after intramuscular or intravenous injection of 40 U/kg (8 micrograms/kg) of elcatonin.

Animals↗
PubMed1985

The usefulness of serum PABA measurement after BT-PABA administration in the diagnosis of chronic pancreatitis.

We examined the maximal serum PABA concentration within 3 hrs (MS-PABA) and the 6 hr urinary PABA recovery (6 hr U-PABA) after BT-PABA administration, PABA excretion index, and chymotrypsin secretory response to caerulein-secretin stimulation in ten control subjects and fifteen patients with chronic pancreatitis diagnosed on the basis of pancreatograms. The results suggested that MS-PABA can distinguish the patients with definite irregular dilatation of the main pancreatic duct from the controls, but not those with localized irregular dilatations of the side branches from the controls. MS-PABA showed a significant correlation with 6 hr U-PABA, PABA excretion index, chymotrypsin output and bicarbonate output. This modified method was shown to be useful in the diagnosis of chronic pancreatitis with unequivocally abnormal pancreatograms and/or markedly decreased chymotrypsin secretion. This modification will serve to simplify the BT-PABA test by eliminating urinary collection and shortening the procedure time.

4-Aminobenzoic Acid↗
PubMed1985

Ultrasonic electrocochleography in guinea pig.

In order to obtain information about how ultrasonic stimuli are perceived (USP) in man, guinea pig cochleae were stimulated by bone conduction with frequencies (98.8 and 143.5 kHz) above the normal auditory field of this animal. The cochlear potentials recorded consisted of CM, SP and AP originating from the basal turn of the cochlea, and were found to be influenced by asphyxia, administration of ethacrynic acid, hypothermia and change of interstimulus interval. In addition, in kanamycin-treated animals the mean AP amplitude decreased to about one fourth of the normal value, and the mean AP latency increased significantly. These findings suggest that there is no special sense organ for the detection of USP but that such sounds activate hair cells in the basal turn of the cochlea.

Animals↗
PubMed1985

Gas analysis of the middle ear cavity in normal and pathological conditions.

The gas of the tympanic bulla was measured using 18 normal and 14 tube-obstructed guinea pigs. The concentrations of CO2 and O2 were 4.8 +/- 1.0% and 7.2 +/- 1.8% in normal animals, and 4.3 +/- 1.6% and 8.1 +/- 2.0% in tube-obstructed animals, respectively. The bulla was opened to room air and then closed again. The recovery process of each gas was examined. In normal animals, CO2 and O2 were exponentially changed toward the pre-open value with time. The time constants of this recovery process were 15 min and 97 min in CO2 and O2, respectively. In tube-obstructed animals, however, this quick recovery of CO2 was significantly delayed (time constant, 50 to 80 min), although there was no effect upon the recovery of O2. This delayed recovery of CO2 is likely to be due to the edema of the mucous membrane.

Animals↗
PubMed1985

Renal involvement in mixed connective tissue disease. Report of 5 cases.

5 cases with the compatible serological criteria of mixed connective tissue disease described earlier are presented. In 1 of them with a moderate degree of proteinuria, the renal biopsy disclosed membranous nephritis. However, despite the absence of overt clinical renal disease in the other 4 cases, biopsies disclosed membranous nephritis in 1 and mild mesangial proliferative glomerulonephritis in the remaining 3 cases. In the follow-up of these 4 cases, 2 subsequently developed abnormal urinalysis. Electron microscopic examinations demonstrated electron-dense deposits in glomeruli, and 4 of these patients also had microtubular structures in the endothelial cytoplasm. Contrarily to the original concept, our findings suggest that mixed connective tissue disease also induces immune complex disease.

Adult↗
PubMed1985

[Effects of anti-tumor drugs and gastrointestinal hormones on the growth of pancreatic duct cell adenocarcinoma in homologous transplanted animal models].

The pancreatic duct cell adenocarcinoma induced by di-isopropanol nitrosamine in Syrian golden hamsters could be easily and repeatedly into the subcutaneous tissues or the pancreas of the homologous animals. We examined the anti-tumor effects of the administration of FT-207 and the coadministration of FT-207 and uracil on the pancreatic cancer transplanted into the subcutaneous tissues and the pancreas. The inhibitory effect on the tumor growth observed in the group treated with FT-207 and uracil was more striking than that in the group treated with only FT-207. Such enhanced anti-tumor effect observed in the coadministration group seemed to be due to the increased 5-FU concentration in the tumor tissues. Some gastrointestinal hormones (cholecystokinin, caerulein, secretin and tetragastrin) injected intraperitoneally promoted the growth of subcutaneously transplanted tumor. These gastrointestinal hormones except tetragastrin also increased the weight of the pancreas. In an analysis of RNA and DNA contents and RNA/DNA ratio in tumor tissues, the promotion of the tumor growth seemed to stem from hyperplasia and/or hypertrophy of the cancer cells. Therefore, it is suggested that some gastrointestinal hormones have trophic actions on the pancreatic duct cell adenocarcinoma as well as normal pancreas.

Animals↗
PubMed1985

[A randomized controlled study of adjuvant immunotherapy with N-CWS for head and neck malignancies].

The nonspecific adjuvant immunotherapeutic effectiveness of the cell wall skeleton of Nocardia rubra (N-CWS) was studied in patients with head-and-neck malignancies. This study involved 390 patients seen from March 1980 to July 1982. The patients qualifying for statistical analysis were limited to 276 with squamous cell carcinoma without a vestige of tumor after four months of radical therapy. They were divided into two background-factors matched groups of 132 immunotherapy and 144 control patients. The overall two-year nonrecurrence rate was 70.4% for the immunotherapy group and 67.1% for the control. This difference, however, was amplified, when the patients' stages were limited to III and IV: 66.6% for the immunotherapy group and 55.3% for the control.

Adjuvants, Immunologic↗
PubMed1984

Nucleotide sequence of Marchantia polymorpha chloroplast DNA: a region possibly encoding three tRNAs and three proteins including a homologue of E. coli ribosomal protein S14.

The nucleotide sequence of a region of Marchantia polymorpha chloroplast DNA was determined. On this DNA sequence (3.38kb), three open reading frames (ORFs) and three putative tRNA genes were detected in the following order: -ORF701-tRNASer(UGA)-ORF702-tRNAGly(GCC)-initiator tRNAMet(CAU)-ORF703-. The ORF703 is composed of 100 codons in which those for lysine (15%) and arginine (11%) are abundant, and could be accounted for as a counterpart of E. coli ribosomal protein S14 since they share 45% homology in the amino acid sequences. The ORF701 appears to code for a membrane protein, showing a periodic appearance of seven clusters of hydrophobic amino acids. Although the mechanisms remain unknown, the ORF701 causes a streptomycin-sensitive phenotype in resistant mutants of E. coli. The ORFs and tRNA genes are separated from each other by extremely AT-rich spacers containing sequences of dyad symmetry. The third letter positions of the codons in the ORFs are also rich in A and T residues.

Base Sequence↗
PubMed1984

Nucleotide sequences of chloroplast 5S ribosomal RNA from cell suspension cultures of the liverworts Marchantia polymorpha and Jungermannia subulata.

The nucleotide sequences of chloroplast 5S rRNAs from cell suspension cultures of the liverworts Marchantia polymorpha and Jungermannia subulata were determined. Their nucleotide sequences, 119 nucleotides long, were highly homologous to each other (96% identity) and had high homology with those from chloroplast 5S rRNAs of two higher plants, tobacco (92% identity) and spinach (92-91% identity), but less homology (87-85% identity) with that from a lower plant, the fern Dryopteris acuminata.

Base Sequence↗
PubMed1984

Effect of kainic acid upon N1 latency.

Although the N1 latency of whole nerve action potential is one of the important pieces of information obtained from ECochG, there are some conflicting opinions as to whether or not it is prolonged in sensorineural hearing loss. Kainic acid (KA) is known to destroy neurons selectively through an action at glutamatergic synapses. Therefore, a model of "neural deafness" was made by perfusing the scala tympani with KA solution. The effect of KA upon cochlear microphonics was minimal. Although the N1 amplitude was markedly suppressed by KA, the N1 latency was neither prolonged nor shortened. The result obtained in the present study strongly suggests that the N1 latency is not prolonged in "neural deafness."

Animals↗