PubMed Health⌕ Search

Biomedical subjects

Y Hayase

Publications and source records attributed to Y Hayase.

At least 91 records · Page 5Linked to original sources
PubMed1987

Synthesis and hybridization studies on two complementary nona(2'-O-methyl)ribonucleotides.

2'-O-Methyl derivatives of the common ribonucleosides except for guanosine were synthesized via the 2'-O-methylation of appropriately-protected nucleosides with CH3I in the presence of Ag2O. The 2'-O-methylguanosine derivative was prepared by the monomethylation of a 2',3'-cis-diol system with diazomethane. These derivatives were converted to protected 2'-O-methylribonucleoside 3'-phosphates and used for oligonucleotide synthesis on polymer supports. Thus, oligo(2'-O-methyl-ribonucleotides) having the sequence identical to the consensus sequence of the 5'-splice junction CAGGUAAGU and its complement were synthesized in a stepwise manner using the phosphotriester method. Thermal stabilities (Tm's) of the duplex of these 2'-O-methyl ribo-oligomers and eight related duplexes containing ribo- or deoxyribo-oligomers were examined. It was found that the 2'-O-methyl oligoribonucleotides can be utilized as an alternative to an oligoribonucleotide probe in RNA hybridizations as the hybrid formed has a high, or a higher Tm, the probe is much easier to synthesize and it is less likely to be enzymatically degraded.

Acetylation↗
PubMed1987

Sequence-dependent hydrolysis of RNA using modified oligonucleotide splints and RNase H.

We found that, in the presence of chimeric oligonucleotides containing complementary deoxyribo- and 2'-O-methylnucleosides, a nonaribonucleotide, [5'-32P]pACUUACCUG, was cleaved specifically upon treatment with RNase H. When 3'm(UG)d(AATG)m(GAC)5' was used as a hybridization strand, pACUUACCUG was cleaved between C6 and C7 to yield pACUUAC. In the presence of 3'm(UGAA)d(TGGA)m(C)5', the nonaribonucleotide was hydrolyzed, mainly between U8 and C9, to give pACUUACCU. This method will have a variety of applications in the field of RNA engineering.

Autoradiography↗
PubMed1987

A new solid-phase synthesis of oligoribonucleotides by the phosphoro-p-anisidate method using tetrahydrofuranyl protection of 2'-hydroxyl groups.

Six nonaribonucleotides containing the 5'-splice site, one complementary nonamer and an octadecamer containing the 3'-splice site have been synthesized on a polymer support using the phosphoro-p-anisidate method. A 5'-linked 2'-O-tetrahydrofuranyl-N-protected nucleoside 3'-(o-chlorophenyl)phosphoro-p-anisidate was used as the starting nucleotide, and the chain elongated in the 3'-direction by removing the p-anisidate protecting group with isoamyl nitrite under neutral conditions. The octadecamer has been synthesized using dinucleotide blocks and a 3'-terminal trinucleotide.

Base Sequence↗
PubMed1987

Sequence-dependent hydrolysis of RNA using modified oligonucleotide splints and RNase H.

To cleave RNA molecules using RNase H in a site-specific manner, a short deoxyoligonucleotide (3-5mer) joining with 2'-O-methyl oligonucleotide(s) was designed as a DNA splint to be used. Model experiments were carried out using ribooligonucleotide substrates (9 and 18 mer). It was found that the use of this type of splints (9 mer) causes a unique cleavage by RNase H. For example, when 3'm (GA)d(AGAA)m(GGU)5' was used as a hybridization strand, 32pUCUUUCUUCUUCCAGGAU was cleaved specifically between U11 and C12 to yield 32pUCUUUCUUCUU. This method will have a variety of applications for the study of RNA.

Base Sequence↗
PubMed1985

Synthesis and properties of novel nucleic acid probes.

2'-O-Methyl derivatives of common ribonucleosides were prepared from appropriately protected nucleosides via the methylation of the 2'-hydroxyl groups with methyl iodide or diazomethane. These derivatives were converted into 2'-O-methylribonucleotide units and the guanosine derivative was linked to a polymer support. Thus, oligo(2'-O-methylribonucleotides) having the sequence of AmCmUmUmAmCmCmUmGm was synthesized in a stepwise manner by using the phosphotriester method. Thermal stabilities (Tm's) of the hybrid between the 2'-O-methyl ribooligomer and the complementary ribooligomer and of the related hybrids are compared. The synthesis of ribooligomer by a new approach is also described.

Base Sequence↗
PubMed1983

[Two cases of primary urethral carcinoma in females].

Two cases of primary female urethral carcinoma are presented and discussed. The patients were 70 years old and 65 years old, and the pathological diagnoses were squamous cell carcinoma and adenocarcinoma, respectively. The patient with squamous cell carcinoma had metastasized inguinal lymph nodes at the first consultation, despite the administration of bleomycin, and the tumor had widely metastasized to skin of the lower extremities. She died of cachexia and disseminated intravascular coagulopathy (DIC). The other patient with adenocarcinoma was treated by postoperative cobalt radiation therapy in a total dose of 6,000 rads. After 18 months, she had recurrence of tumor in urethra, and developed Virchow's node metastasis, she died of acute renal failure. Both patients died within two years.

Adenocarcinoma↗
PubMed1980

Dissolution of cystine stones by irrigated tiopronin solution.

A new method involving the introduction of tiopronin solution directly into the renal pelvis or bladder has been developed for the treatment of cystine stones. Therapeutic irrigation by tiopronin solution was done in 4 cases of residual cystine kidney stones using a nephrostomy tube, and in an infant with bladder cystine stones using a Foley 3-way catheter. In every case all of the cystine stones were dissolved completely. During the course of the treatment no abnormality was noted on blood, liver function or immunological tests. Neither have there been any negative side effects, such as eruption, anorexia, nausea, diarrhea or general fatigue. The significance of this irrigation process is that whereas nephrectomy, heminephrectomy or nephrolithotomy was necessary previously to remove kidney cystine stones, now only pyelolithotomy and nephrostomy tube insertion are necessary. Furthermore, an operation is unnecessary in cases of bladder cystine stone dissolution by tiopronin irrigation.

Adolescent↗