Biomedical subjects

M Momiyama

Publications and source records attributed to M Momiyama.

13 recordsLinked to original sources

PubMed1997

Construction of cDNA bank from biopsy specimens for multiple gene analysis of cancer.

We constructed a "cDNA bank" of human colorectal cancer and surrounding normal tissues with our unique mRNA assay system. Total nucleic acids extracted from patients' tissues were applied to 96-well plates, where poly(dT) sequences of oligonucleotides were immobilized. After hybridization, the cDNA was reverse-transcribed on the plate with the captured mRNA as a template, followed by synthesis of double-stranded (ds) cDNA. The resulting sense cDNA was removed from the plate, then used in PCR for analysis of various genes. The sense strand of the cDNA was repeatedly synthesized by using the immobilized antisense cDNA as a template even from plates used once and stored at 4 degrees C for as long as 6 months. Furthermore, the results of PCR could be easily compared among different specimens if the same amount of total mRNA were applied to the plate for the ds cDNA synthesis. This demonstrated that the cDNA bank constructed from clinical materials provides almost unlimited supplies of cDNA for multiple gene analysis of cancer.

Actins↗

PubMed1995

Simultaneous visualization of Q-bands and FISH signals using a novel fluorochrome.

We developed a new HNPP-azo dye method for detection of fluorescence in situ hybridization (FISH) signals on Q-banded chromosomes by use of a newly synthesized fluorochrome, HNPP (3-hydroxy-N-2'-biphenyl-2-naphthalenecarboxamide phosphate ester), which reacts enzymatically with alkaline phosphatase and azo dye. The FISH staining method permits simultaneous detection of orange HNPP signals on chromosomal sites labeled by Q-banding, allowing the assignment of small (440-1,200 bp) probes.

Animals↗

PubMed1992

AT1 angiotensin receptors mobilize intracellular calcium in a subclone of NG108-15 neuroblastoma cells.

The effects of angiotensin II (AII) and related peptides on the mobilization of internal Ca2+ were studied in a subclone of NG 108-15 cells. The subclone, C1, was prepared by fluorescence-activated cell cloning using a rapid response kinetics and a large response magnitude following stimulation by AII as the selection criteria. Angiotensin I, AII, and angiotensin III (AIII) stimulated Ca2+ mobilization in the C1 cells in a concentration-dependent manner (1 nM-100 microM), yielding EC50 values of 437 +/- 80 nM (n = 4; slope = 1.6 +/- 0.3), 57 +/- 8 nM (n = 12; slope = 1.5 +/- 0.3), and 36 +/- 5 nM (n = 7; slope = 1.4 +/- 0.3), respectively. AIII was significantly more potent than AII (p less than 0.05). In contrast, Des-Phe8-AII, AII-hexapeptide (AII 3-8), and p-NH2-Phe6-AII (1-10 microM) were inactive as agonists. Although the effects of AII and AIII in C1 and parent NG108-15 cells were totally inhibited by the AT1 receptor-selective nonpeptide antagonist, DUP-753 (0.3-1 microM), the AT2-selective antagonists, EXP-655 and CGP42112A (1-10 microM), failed to block the effects of AII. DUP-753 (0.3-100 nM) produced dextral shifts of the AII-induced concentration-response curves and yielded an estimated affinity constant (pA2) of 8.5 +/- 0.2 (n = 16) using single-point analysis involving different concentrations of DUP-753. These data compared well with those obtained for the inhibition of AII-induced aortic contractions by DUP-753 (pA2 = 8.5) reported previously by others.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin I↗

PubMed1988