Search PubMed⌕ Search

Biomedical subjects

A Ono

Publications and source records attributed to A Ono.

At least 235 records · Page 13Linked to original sources
PubMed1987

Synthesis of decadeoxyribonucleotides containing N6-methyladenine, N4-methylcytosine, and 5-methylcytosine: recognition and cleavage by restriction endonucleases (nucleosides and nucleotides part 74).

The naturally-occurring modified bases, N6-methyladenine, N4-methylcytosine, and 5-methylcytosine were chemically introduced in place of the adenine or cytosine in the decadeoxyribonucleotides containing recognition sequences of Bgl II, Sau 3AI, Mbo I and Mfl I. The modified oligomers bind to the enzymes but the rates of cleavage by the enzymes are variable.

5-Methylcytosine↗
PubMed1987

Age-related changes in trimethadione oxidizing capacity.

The metabolism of trimethadione (TMO) following oral administration (4 mg kg-1) has been studied in 11 young male and 11 elderly male patients. The elimination half-life (h) of TMO was 11.8 +/- 1.4 (mean +/- s.e. mean) in the young and 23.5 +/- 2.17 in the elderly (P less than 0.01). Total body clearance (1 h-1 kg-1) was 41.4 +/- 2.8 in the young and 29.0 +/- 2.4 in the elderly (P less than 0.01). The apparent volume of distribution (1 kg-1) was 0.67 +/- 0.03 in the young and 0.65 +/- 0.04 in the elderly. Serum dimethadione (DMO)/TMO ratios at 4 h were 0.65 +/- 0.03 in the young and 0.46 +/- 0.03 in the elderly (P less than 0.01). These results suggest that N-demethylation of TMO is inversely related to age.

Adult↗
PubMed1987

Trimethadione metabolism in patients with normal liver and in patients with chronic liver disease.

Serum dimethadione (DMO)/trimethadione (TMO) ratios after oral administration of TMO have been investigated in 10 patients with normal livers, 8 patients with hepatoma and 8 patients with hepatoma and cirrhosis. Serum concentration ratios of DMO to TMO at 4 h after oral administration of TMO in patients with chronic liver disease were significantly decreased by 27% for those with hepatoma and 52% for those with hepatoma and cirrhosis. Serum DMO/TMO ratios at 4 h correlated well with liver function characteristics (total protein r = 0.741, plasma albumin r = 0.826, total bilirubin r = -0.725, cholinesterase r = 0.853) as well as with pharmacokinetic parameters (total body clearance r = 0.852, half-life r = -0.636) in both patients with normal livers and patients with chronic liver disease. This study suggests that serum DMO/TMO ratios in a blood sample obtained by a single collection after an oral administration of TMO might provide a clinically useful index of the hepatic drug-oxidizing capacity in an individual patient with chronic liver disease without determining the liver function characteristics or the pharmacokinetic parameters.

Carcinoma, Hepatocellular↗
PubMed1986

CD spectra and some properties of deoxyoligonucleotide duplexes having a C:G terminus (nucleosides and nucleotides. Part 69).

In the course of an investigation of the mode of recognition of nucleotide sequences with restriction endonucleases, several deoxyoligonucleotide duplexes having G:C terminal base pairs were synthesized. The oligonucleotides having a 5'-C (3'-G) terminus showed unusual CD spectra with a negative band at the longer wavelength region, when compared to those of the same internal sequences but a 5'-G (3'-C) terminus, which showed a positive band like the B- or A-DNA type. The nature of these CD spectra was compared with those of the Z-DNAs on the effect of salt concentrations, intercalation with ethidium bromide, or 31P-NMR spectra. These unusual spectra may be attributed to the terminal effect of the 5'-C:3'-G pairs.

Base Sequence↗
PubMed1986

Trimethadione tolerance test for evaluation of functional reserve of the liver in patients with liver cirrhosis and esophageal varices.

Dimethadione (DMO)/trimethadione (TMO) ratios in serum after oral administration of TMO were investigated in 15 normal subjects and in 20 patients with cirrhosis and esophageal varices. Severe impairment of liver function was associated with a decrease in total cholesterol, total protein and plasma albumin, or an increase in total bilirubin, serum glutamic oxaloacetic transaminase, serum glutamic pyruvic transaminase, serum gamma-glutamyl transpeptidase and indocyanine green retention rate (ICG R15). Serum concentration ratios of DMO to TMO at 2 or 4 h after oral administration of TMO in patients were significantly decreased by 67 or 66%, respectively, compared to normal subjects. DMO/TMO ratios at 2 or 4 h following oral administration of TMO were well correlated with the liver function parameters (plasma albumin r = 0.758 at 2 h, r = 0.776 at 4 h; total protein r = 0.613 at 2 h, r = 0.619 at 4 h; ICG R15 r = -0.683 at 2 h, r = -0.746 at 4 h, in patients only; cholinesterase r = 0.873 at 2 h, r = 0.908 at 4 h) as well as with pharmacokinetic parameters (total body clearance r = 0.794 at 2 h, r = 0.786 at 4 h) in both the normal subjects and the patients. It suggests that the DMO/TMO ratio obtained in a single blood sample collected after oral administration of TMO might provide a useful measure for function hepatic reserve.

Adult↗
PubMed1986

Hepatic trimethadione-oxidizing capacity remains normal in patients with extrahepatic cholelithiasis.

In the present study, using trimethadione (TMO) as an indicator substrate, we estimated pre- and post-operative differences in hepatic drug-oxidizing capacity in patients with extrahepatic cholelithiasis. Only total and direct bilirubin values were significantly higher in preoperative patients than in the controls. After operative procedures, those parameters did not show significant differences from corresponding control values. The serum dimethadione (DMO)/TMO ratios estimated 4 h after administration of 4 mg/kg of TMO. Neither pre- nor post-operative serum DMO/TMO ratios were significantly different from those in the controls. These results suggest that the hepatic drug-oxidizing capacity in patients with extrahepatic cholelithiasis remains unchanged even though the bilirubin level deviated from normal.

Bilirubin↗
PubMed1985

RNA tumor virus in human thymomas and thymus hyperplasias.

Human thymomas and thymus hyperplasias were examined for retroviruses. Most of these patients were complicated by systemic immunological diseases such as myasthenia gravis and pure red cell aplasia. The thymus cells were co-cultured with allogenic B cells or peripheral blood lymphocytes (PBL) pretreated with mitomycin C. Retrovirus-like particles were demonstrated in cultured thymus cells in all cases of thymomas and thymus hyperplasias examined by electron microscopy. In most cases, these particles were detected in thymus epithelial cells. Reverse transcriptase activity sedimenting at a density of 1.15-1.17 gm/cm3 in sucrose density gradients was eluted in the culture fluids. Retrovirus-like particles were demonstrated in human T cells infected with these particles. Antibodies to virus-infected T cells were detected in sera of the patients with thymoma and thymus hyperplasia. These results suggest that in thymomas and thymus hyperplasias, retroviruses that can be induced, following a proliferative stimulus, may be involved in the genesis of thymic disorders and in the pathogenesis of systemic immunological diseases.

Adult↗
PubMed1985

Duplication of the caecum in a neonate simulating intussusception.

A case of caecal duplication in a 36-h-old neonate is described. The patient presented with vomiting and an abdominal mass and the barium enema finding was initially suggestive of intussusception. At laparotomy a duplication cyst completely obstructing the lumen was found. This was considered to have given the radiological picture simulating intussusception.

Barium Sulfate↗
PubMed1985

Changes in the intraluminal protein digestion of pancreatic duct-ligated rats.

After ligature of the pancreatic duct (PDL), the body weight of rats decreased for several days, but began to increase from day 7, returning to that at the time of the operation on day 14. In these PDL animals, the weight gain was not due to improved digestion resulting from duodenal leakage of pancreatic enzymes or a compensatory increase of proteolytic enzyme activities in the intestinal mucosa. There was no significant difference in pepsin activities in the gastric contents and mucosa of control and PDL rats. However, acidic proteolytic activity, with a pH range between 1 and 4 and an optimum at pH 2.8, was found to be extremely high in the intestinal contents of PDL rats. Furthermore, the intraluminal pH of PDL rats was maintained below 4.0, especially in the upper small intestine, because of the absence of pancreatic bicarbonate secretion, suggesting that compensatory digestion by acidic proteolysis accounted in part for the growth of PDL rats. The transit time of orally administered material through the gastrointestinal (GI) tract in PDL rats was longer than that in control rats on days 7 and 14. These results suggest that the weight gain of PDL rats was caused by compensatory digestion by acidic proteolysis in the small intestine and prolongation of the transit time through the GI tract.

Animals↗
PubMed1985

[Calcinosis universalis with hyperphosphataemia--successful treatment with phosphorus deprivation].

Seven year old boy with calcinosis universalis associated with high serum phosphorus was reported. Over one year's treatment with aluminum hydroxide up to 18 grams per day have reduced calcified mass remarkably, while serum phosphorus levels were remaining still above the normal range. Concomitant use of probenecid seemed to be effective in reducing serum phosphorus levels as well as decreasing the calcified mass. Pathogenetic mechanisms of soft tissue calcification in calcinosis universalis is not clear, but in this case hyperphosphataemia is considered to be one important factor accelerating soft tissue calcification. Although hyperphosphataemia associated with tumoral calcinosis has been frequently observed, no report is yet available on calcinosis universalis associated with hyperphosphataemia. This case might represent one unique type of calcinosis.

Aluminum Hydroxide↗
PubMed1985

Effect of terminal base pairs on the CD spectra of oligodeoxynucleotide duplexes.

Oligodeoxynucleotide duplexes having terminal C:G base pairs and recognition sequences for restriction endonucleases Bgl II and Sau 3Al were synthesized by the solid or liquid phase phosphotriester approach. Among them, the self-complementary oligonucleotides with C or CC at the 5'-end and G or GG at the 3'-end exhibited unusual CD spectra in contrast to those of the usual B-DNA type CD spectra of the oligonucleotide with G or GG at the 5'-end. The spectra are different to those of the Z-DNA, and regarded to the terminal base effect of the C:G pairs.

Base Composition↗
PubMed1984

Synthesis of deoxyoligonucleotides containing 7-deazaadenine: recognition and cleavage by restriction endonuclease Bgl II and Sau 3AI (nucleosides and nucleotides Part 55).

Deoxydecanucleotides having a recognition sequence of Bgl II and Sau 3AI, and their 7-deazaadenine analogs were synthesized. The decanucleotides containing 7-deazaadenine in place of adenine were partially resistant to the hydrolysis by Sau 3AI and strongly resistant to that by Bgl II. A new hypothesis on the mode of recognition and cleavage of specific nucleotide sequences by Bgl II, recognizing one strand and cleaving the other strand, is presented.

Adenine↗