The molecular mechanism by which poly(ADP-ribose) participates in DNA repair was investigated using purified DNA ligase in DNA-histone systems. The ligase activity was markedly inhibited by histones; the inhibition was greater than 80% with histone H1 at concentrations equal to DNA. This inhibition was reversed efficiently by poly(ADP-ribose), either added exogenously or synthesized in situ with poly(ADP-ribose) synthetase. The reversal effect was specific for poly(ADP-ribose); other polyanions such as mRNA, rRNA's, tRNA, and synthetic poly(A) were less effective or totally ineffective. The poly(ADP-ribose) effect appeared to be caused by binding to histones and decreasing DNA-histone interactions. Poly(ADP-ribose) also had high affinity for DNA ligase. These observations, together with the findings of absolute dependence of poly(ADP-ribose) synthetase activity on DNA strand ends and extensive automodification of the synthetase in DNA-damaged cells, suggested a possible mechanism of poly(ADP-ribose) action in DNA repair, in which auto-modified poly(ADP-ribose) synthetase serves as a link between DNA damage and activation of DNA ligase.

DNA Ligases↗

PubMed1983

[Case of feminizing adrenocortical tumor].

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Adrenal Cortex Neoplasms↗

PubMed1983

[Factors affecting the early prognosis in acute myocardial infarct of the aged--prognosis based on multivariate analysis].

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Aged↗

PubMed1983

A new, convenient method for determining T residues in chemical DNA sequencing by using photoreaction with spermine.

Irradiation of 3'-[32p]-labeled DNA fragments with 254-nm light in the presence of spermine resulted in a T specific cleavage of the DNA chain without piperidine treatment. In the presence of methylamine G + T reactions (G greater than T) were observed under the same irradiation conditions. The T reaction with spermine and the G greater than reaction with methylamine may be combined with the standard Maxam-Gilbert's C + T reaction to provide confirmatory determination of DNA sequences.

Base Sequence↗

PubMed1983

Reduced mitomycin C induces heat-labile sites in DNA at specific sequences.

We have investigated the sequence specificity of DNA damage induced by mitomycin C reduced with NaBH4, by using 3'- or 5'-end labeled DNA fragments of defined sequence. Mitomycin C reduced with NaBH4 induced heat-labile sites in DNA preferentially at specific sequences. The most preferred trinucleotide sequence for induction of heat-labile sites was GGT, followed by GGG, AGT, GAG, GGC and AGG. Active oxygens such as hydroxyl radical and singlet oxygen, and metal ions were involved in the induction of heat-labile sites. DNA was broken at the 3' side of deoxyguanosines and some of deoxyadenosines by heat-treatment. The produced oligonucleotides contained phosphoryl groups at the 5' termini. The 3' termini seemed not to have simple structures.

Base Sequence↗

PubMed1983

[The blood flow in the peripheral arterial occlusive disease--investigation by 133Xe clearance method].

The blood flow in the lower extremities was investigated before and after surgery on patients with peripheral arterial occlusive disease by 133Xe clearance method in order to evaluate results of sympathectomy and reconstructive arterial surgery. Sixty-four patients, 54 with arteriosclerosis obliterans, 7 with thromboangiitis obliterans and 3 with Raynaud's disease were divided in two groups. Skin blood flow was measured in one group and muscle blood flow in another one. Flow was measured at rest in the former, while at rest, during and after exercise in the latter. The following results were obtained. The preoperative clearance was correlated with severity of the disease. Skin blood flow increased after sympathectomy more than reconstructive arterial surgery. Muscle blood flow before and after reconstructive surgery increased adequately at rest and under reactive hyperemia. The 133Xe clearance method is a simple and reliable test for evaluation of the blood flow in the extremities.

Adult↗

PubMed1983

[Treatment of tumors of the urinary bladder with so-called immunopotentiators].

Eighty-eight cases of urinary bladder tumor were treated in our Department from 1976 to 1978. The effect of so-called immunopotentiators (OK-432, Levamisole and PSK) was studied in 23 patients. The following results were obtained. Pretreatment intracutaneous response to PHA was significantly lower in the high stage and high grade group than in the low stage and low grade group (P less than 0.025). However, there was no correlation between the effect of immunotherapy and PHA skin reaction. Of the immunoglobulins, only IgM was significantly lower in the high grade group than in the low grade group (P less than 0.025). The one-year survival rate for the patients in the high stage group was higher receiving immunotherapy than those not treated. This suggests that immunotherapy may be useful for prolonging the survival time of patients with advanced bladder carcinoma.

Adjuvants, Immunologic↗

PubMed1983

[A case of retroperitoneal malakoplakia].

A case of retroperitoneal malakoplakia is reported. A 50-year-old female was admitted with the chief complaint of right flank pain. Intravenous pyelography, computed tomography, selective iliac arteriography and abdominal echography revealed right pararenal abscess and the right renal tumor suspected. About one liter of yellowish fluid was drained from the retroperitoneal space, but no right renal tumor was found. Pathological diagnosis was retroperitoneal malakoplakia postoperatively. This is assumed to be the second case of retroperitoneal malakoplakia in Japan.

Female↗

PubMed1983

[Pulsatile flow dynamics of the ductus arteriosus, thoracic aorta and pulmonary artery in patients with patent ductus arteriosus].

In 20 infants or children with an isolated or complicated patent ductus arteriosus (PDA), we qualitatively and quantitatively studied pulsatile flow dynamics of the ductus, descending thoracic aorta and pulmonary artery by means of a catheter-tip electromagnetic flow velocity probe. They were divided into four groups according to ductal shunt states as follows: 14 patients with a continuous left-to-right (L-R) shunt (Group I), three patients with a bidirectional but a dominant L-R shunt (Group IIA), two patients with a bidirectional but dominant right-to-left (R-L) shunt (Group IIB), and one patient without a significant ductal flow (Group III). In Group I, the ductal flow was pulsatile and showed continuous L-R shunting. The timing of a peak flow velocity was coincident with the peak aortic pressure at the mid-ductus, and it shifted to diastolic phase as the flow sensor approached the pulmonary end of the ductus arteriosus. In Group IIA, the peak velocity of a L-R shunt flow was located at mid-diastole and a transiently reversed R-L shunt flow was seen during systole. Two patients of Group IIB showed that the peak flow velocity of a dominantly reversed shunt was at mid-diastole, while a low grade L-R shunt flow was seen over a wide range of diastolic period. One patient of Group III who underwent operation for aortic arch interruption did not show any significant ductal flow because of a narrow PDA. In most cases of the present study, a diastolic backflow reflecting a L-R ductal shunt during diastole was demonstrated both in the descending thoracic aorta and main pulmonary artery. The peak flow velocity of the thoracic aorta was correlated with the ductal L-R shunt ratio determined by the Fick method (r = 0.46), and the diastolic regurgitant flow fraction of the thoracic aorta was increased in patients with a larger L-R shunt or with a reversed shunt. Therefore, it was suggested that a net forward flow of the thoracic aorta is reduced in these patients. On the other hand, the quantitative evaluation of a pulmonary flow during systole was found unreliable and expected to be underestimated because of the occurrence of turbulence at the site of the main pulmonary artery by the confluence of ejection stream from the right ventricle and a shunted flow from the aorta.(ABSTRACT TRUNCATED AT 400 WORDS)

Aorta, Thoracic↗

PubMed1983

Lipoperoxides, vitamin E, and activities of superoxide dismutase, glutathione peroxidase, and catalase in regenerating rat liver.

Lipoperoxides in homogenates of regenerating rat liver increased from 6 hours after the operation and reached a peak (about 7 times the control level) 18-24 hours after the operation. The concentration of blood lipoperoxides rapidly decreased after the operation. The enzymatic activities of superoxide dismutase, catalase, and glutathione peroxidase, and vitamin E content in regenerating livers were also determined. Among these antioxidant factors, the catalase level changed markedly.

Animals↗