Biomedical subjects

T Oda

Publications and source records attributed to T Oda.

At least 523 records · Page 29Linked to original sources

PubMed1989

Studies on bleomycin-induced repair DNA synthesis in permeable mouse ascites sarcoma cells.

To study the mechanism of DNA excision repair, a DNA repair system employing permeable mouse sarcoma (SR-C3H/He) cells was established and characterized. SR-C3H/He cells were permeabilized with a 0.0175% Triton X-100 solution. The permeable cells were treated with 1 mM ATP and 0.11 mM bleomycin, and then washed thoroughly to remove ATP and bleomycin. Repair DNA synthesis occurred in the bleomycin-damaged, permeable SR-C3H/He cells when incubated with ATP and four deoxyribonucleoside triphosphates. The repair nature of the DNA synthesis was confirmed by the BrdUMP density shift technique, and by the reduced sensitivity of the newly synthesized DNA to Escherichia coli exonuclease III. The DNA synthesis was optimally enhanced by addition of 0.08 M NaCl. Studies using selective inhibitors of DNA synthesis showed that aphidicolin-sensitive DNA polymerase (DNA polymerase alpha and/or delta) and DNA polymerase beta were involved in the repair process. The present DNA repair system is thought to be useful to study nuclear DNA damage by bleomycin, removal of the damaged ends by an exonuclease, repair DNA synthesis by DNA polymerases and repair patch ligation by DNA ligase(s).

Animals↗

PubMed1989

A cell-free system for studying a priming factor involved in repair of bleomycin-damaged DNA.

A simple cell-free system for studying a priming factor involved in the repair of bleomycin-damaged DNA was established. The template-primer used for the repair DNA synthesis was prepared by treating the closed circular, superhelical form of pUC19 plasmid DNA with 2.2 microM bleomycin and 20 microM ferrous ions. Single-strand breaks were introduced into pUC19 DNA by the bleomycin treatment, and the DNA was consequently converted largely into the open circular form. A system for repair of this bleomycin-damaged DNA was constructed with a priming factor, DNA polymerase (DNA polymerase beta or Klenow fragment of DNA polymerase I), ATP, T4 DNA ligase and four deoxynucleoside triphosphates. After incubation, the conformation of the DNA was analyzed by agarose gel electrophoresis and electron microscopy. The open circular DNA was largely converted to the closed circular DNA, indicating that the single-strand breaks of DNA were repaired. When the priming factor was omitted, DNA repair did not occur. The present system seemed to be applicable to the study of priming factors involved in the repair of DNA with single-strand breaks caused not only by bleomycin but also by ionizing radiation or active oxygen.

Bleomycin↗

PubMed1989

Unique features of monoclonal IgG2b in the cleavage reaction with pepsin.

Preparations of IgG2b purified from several mouse hybridoma clones were highly susceptible, compared to other subclasses, to peptic digestion under conditions usually used to prepare F (ab')2 fragments. Analyses of the digestion products revealed that no F (ab')2 was produced and that the main product was a Fab-like fragment. Demonstration of the hinge disulfides in the Fc portion clearly indicated that in IgG2b the primary peptic cleavage occurs on the NH2-terminal side of the inter-heavy chain disulfide bridge. The resulting Fab failed to bind with antigen, suggesting the importance of the CH1-hinge region in maintaining the native conformation of the antigen-binding site.

Animals↗

PubMed1989

Eosinophil hyporesponse of jirds induced by microfilariae of Brugia pahangi.

Male jirds (Meriones unguiculatus) were inoculated sc with 100 infective larvae of Brugia pahangi. After 16 weeks, the animals were reinoculated with a comparable number of organisms. Blood eosinophil responses during the 5 weeks subsequent to this attempt to reinfect were much lower than those of comparable naive animals, while the response to a heterologous infection (Toxocara canis) was comparable to that of controls. Mebendazole was given to infected animals for 2 weeks beginning 5 weeks (prepatent) or 16 weeks (patent) after infection. At comparable intervals after drug administration, the animals were reinoculated with infective larvae and the blood eosinophil response was measured over a 5 week period. The response in the animals treated during the prepatent period was higher than the untreated infected controls. Treatment during the patent period had no demonstrable effect. Jirds made artificially microfilaremic by intravenous inoculation of viable filaria before and after the standard infecting dose had a low eosinophil response to infective larvae. A primary experience of jirds with the microfilariae of B. pahangi evokes an eosinophil response. Subsequent inoculation of larvae did not produce a comparable response.

Animals↗

PubMed1989

ADP effects on bleomycin-induced DNA repair synthesis and adenylate kinase activity in permeable mouse sarcoma cells.

DNA repair in bleomycin-pretreated, permeable mouse sarcoma (SR-C3H/He) cells requires ATP for at least two steps, the repair DNA synthesis step and the repair patch ligation step. ADP can apparently replace ATP in both steps. Maximal, 1.5-2 fold stimulation of repair DNA synthesis was observed with 5-10 mM ADP as well as 2.5-5 mM ATP. Repair patch ligation in the presence of 2.5 mM ADP occurred at almost the same high efficiency as it did in the presence of ATP. The ADP effect on DNA repair patch ligation was attributed to ATP formed from ADP by adenylate kinase in permeable cells, however the ADP effect on repair DNA synthesis could not be attributed solely to the formation of ATP in the same manner.

Adenosine Diphosphate↗

PubMed1989

[Effects of anticancer agents on 7, 12-dimethylbenz (a) anthracene induced rat ovarian cancer cell line (DMBA-OC-1) and human ovarian serous adenocarcinoma cell line (KOC-1S)].

The antitumor activities of five anticancer drugs, at IC50 dosages cisplatin (CDDP), adriamycin (ADM), etoposide (VP-16), mitomycin C (MMC) and carboplatin (CBDCA) were studies an 7,12-dimethylbenz (a) anthracene induced rat ovarian cancer cell line (DMBA-OC-1) and a human ovarian serous adenocarcinoma cell line (KOC-1S). The IC50 dosage of anticancer drugs for DMBA-OC-1 was: CDDP 0.2 microgram/ml. ADM 0.04 microgram/ml, VP-16 3.0 microgram/ml, MMC 0.1 microgram/ml and CBDCA 10.0 micrograms/ml. The results of our study except those for MMC were parallel with those published on in vivo studies. The IC50 dosages of DMBA-OC-1 did not have enough antitumor activity for KOC-1S, whereas the original KOC-1S tumor strongly resisted the combination chemotherapy (CDDP, ADM and cyclophosphamide). Therefore, our findings suggested the possibility of the separation of multiple drug resistant clones from KOC-1S. These two cell lines had quite different antitumor activity characteristics.

9,10-Dimethyl-1,2-benzanthracene↗

PubMed1989

A mechanism of c-raf-1 activation: fusion of the lipocortin II amino-terminal sequence with the c-raf-1 kinase domain.

In order to understand the mechanism of oncogenic activation, we have analyzed the c-raf-1 gene from the GL-5-JCK human glioblastoma, which underwent rearrangement during transfection experiments. Nucleotide sequencing of cDNA clones derived from the 2.5 kb raf-mRNA, which is a major transcript of raf in NIH3T3 cells transformed with GL-5-JCK DNA, revealed that this mRNA contains sequences derived from the human c-raf-1 gene and the human lipocortin II gene. Translation of the 2.5 kb raf-mRNA predicted a fusion protein consisting of 16 amino-terminal amino acid residues of the lipocortin II and 370 carboxy-terminal amino acid residues of the c-raf-1 protein which contains the kinase domain. Expression of the lipocortin II-raf cDNA using the murine sarcoma virus long terminal repeat as promoter resulted in the transformation of NIH3T3 cells.

Annexins↗

PubMed1989

[Antitumor activities of oily suspended YM881 (SMANCS) against VX2 carcinoma].

YM881 (MW 15,000) is a conjugate protein preparation of two copolymer of styrene-maleic acid [SMA] (MW 1,500) and neocarzinostatin [NCS] (MW 12,000). Antitumor activities of YM881 and NCS with or without oily solvent injected arterially against VX2 carcinoma of rabbits were examined. Based on the growth and histological examination of the tumor, remarkable anti-tumor activities were observed with oily suspended YM881 but not with the other group. This results indicate that targeting of the anticancer agent to the tumor is most important for eliciting of antitumor activities.

Animals↗

PubMed1989

[Clinicopathological study of malignant ovarian germ cell tumor].

In treating malignant germ cell tumors clinicopathologically at Kurume University Hospital, for 18 years, the total number of patients was 112, including 25 yolk sac tumors (YST), 10 mixed form germ cell tumors (MF), 36 dysgerminomas (DYS), 26 immature teratomas (IT), 2 choriocarcinomas (CHO) and 13 dermoid cysts with malignant transformation (DCMT). The average age of patients in each group was 25.9 years for DCMT patients. When DCMT cases were excluded, ages was closely related to the age of menarche in each patient. The 5 year survival rate for each germ cell malignancy after the first operation was 31.6% for YST cases, 20.0% for MF, 76.7% for DYS, 60.0% for IT and 50.0% for DCMT cases. Despite currently used aggressive kinds of chemotherapy, the clinical stage still had a prognostic significance in all malignant germ cell tumors except dysgerminoma. Since histological maturation of the tumor tissue following treatment courses was observed in YST and IT cases, the possibility of a relationship between prognosis and the histogenetic process was shortly discussed.

Adolescent↗

PubMed1989

[The effect of pulsatile perfusion on aortocoronary bypass grafting].

To evaluate the effect of pulsatile perfusion on myocardial protection and peripheral circulation, 23 patients undergoing aortocoronary bypass grafting were studied by dividing two groups; one with pulsatile perfusion technique (11 patients) and the other with non-pulsatile (12 patients). The cardiac functional assessments were made on CI, LVSWI, PCWP, CVP at 3, 6, 12 and 24 hours after the operation and the enzyme (CPK, CPK-MB, LDH, GOT) sampling were performed on 1, 2, 4 and 7 days after the operation. The difference between esophageal and rectal temperature, and urine output during cardiopulmonary bypass, indicating the peripheral circulation, were also measured. From these clinical results, it is concluded that pulsatile perfusion method is to be beneficial in myocardial protection and peripheral circulation during operation of aortocoronary bypass grafting.

Adult↗

PubMed1989

Amino acid sequence of nerve growth factor purified from the venom of the Formosan cobra Naja naja atra.

Nerve growth factor (NGF) was isolated from the venom of the Formosan cobra (Naja naja atra). The amino acid sequence was determined by a combination of conventional methods. The total number of amino acid residues was 116, giving a molecular mass of 13,057 Da. The sequence was identical with that deduced from the nucleotide sequence of an NGF cDNA from the venom gland of Naja naja siamensis, reported by Selby et al. [J. Neurosci. Res., 18, 293-298 (1987)].

Amino Acid Sequence↗

PubMed1989

Rapid methods to visualize Y-specific repeated DNA sequences in cytological preparations.

We described rapid methods to detect Y-specific repeated DNA sequences in cytological preparations using in situ hybridization. A human Y chromosome specific DNA probe with an insert equivalent to that in pHY2.1 was labelled with [alpha-32P]dCTP or photobiotin, and hybridized to chromosome preparations. Signals were visualized specifically on Y chromosomes after 1 day's autoradiography or a couple of hours treatment with streptavidin alkaline phosphatase/BCIP/NBT. These methods are useful for molecular confirmation of Y-autosomal translocations.

DNA↗

PubMed1989

[Treatment of threatened premature labor due to subclinical intrauterine infection].

Recent reports reveal that some threatened premature labors (tpl) are caused by intrauterine infections. And the prognosis of tpl due to intrauterine infections are worse than tpl due to other factors because of lower sensitivity to the beta-stimulants. So we examined the relationship between tpl and intrauterine infections retrospectively by obtaining intracervical cultures of inpatients who suffered from tpl, and prospectively by getting intracervical cultures from healthy pregnant women at a gestational age around 20 weeks, and divided them into two groups--the infectious group and non-infectious group--and studied the tpl rate. The patients who had positive bacterial cervical cultures were again divided into two groups. One group had antibiotics administered orally and the other had none. The tpl rate was observed. The results are: 1. Thirty two point six percent of tpl inpatients were found to be infected intracervically. No statistical significance was noted in the microbodies detected. 2. Three cases of premature labor at less than 35 gestational weeks were observed in the infected group. 3. The majority of infected group showed high CRP levels, and the study of Preterm Labor Score (PLS) showed that most cases over 4 points of PLS were infected. 4. In a prospective study, 18 of 100 healthy pregnant women showed positive intracervical bacterial cultures. The tpl rates were 44.4% in all of the infected group. Twenty two point two percent of tpl rate in the antibiotic administration group and 66.7% in the non-administration group (p less than 0.01). And the non-infected tpl rate was 11.0% (p less than 0.01), or only 9 cases out of 82.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗

PubMed1989

The effect of alpha-interferon on the liver in a patient with hairy cell leukemia: light and electron microscopic studies.

A daily dose of 3 x 10(6) or 6 x 10(6) units of alpha-interferon was given during two 4- to 6-month periods to a 65-yr-old male patient with hairy cell leukemia, reducing splenomegaly and decreasing the number of hairy cells. Liver biopsy specimens taken during treatment revealed predominantly decreased hairy cell infiltration in the dilated sinusoids and enlarged or vacuolar nuclei of hepatocytes, compared with those in the liver before treatment. The ultrastructure of hepatocytes in specimens taken during treatment showed cytoplasmic vacuoles, weakly stained glycogen particles, and conspicuously decreased endoplasmic reticulum. Liver tests revealed decreased serum cholinesterase and total cholesterol levels in the early stage of treatment, low levels of total protein and albumin during treatment, and a very low value in the [13C]aminopyrine breath test. No clinical reports have been made on the decreased microsomal function during treatment with interferon. alpha-Interferon damaged the endoplasmic reticulum of hepatocytes, although it was effective for the reduction of hairy cells in the liver of hairy cell leukemia.

Aged↗

PubMed1989

[A case of systemic lupus erythematosus associated with meningitis, myelitis, and bilateral optic neuritis].

A 16-year-old girl was admitted to our hospital in August 23, 1986, for headache, nausea and low grade fever. Marked increases in immunoglobulin indices were found in the cerebrospinal fluid. When she was 13, she was diagnosed as having SLE and lupus nephritis. On September 9, 1986, she complained of urinary retention, and pathological reflexes were elicited bilaterally. On September 13, she complained of a sudden loss of vision (count fingers) in the right eye which worsened to a visual acuity of light perception over the next 48 hours. A visual evoked response potentials (VEP) to flash stimulation gave a loss of amplitude and an increase in latency. On September 16, she complained of a similar loss of vision in the left eye. Leakage of dye around the left optic disc was found by a fluorescein angiogram on September 26. These results indicated a diagnosis of bilateral optic neuritis. Both visual acuity returned rapidly over the following month following oral prednisolone treatment. Optic neuritis is an exceedingly rare complication in SLE. Although the visual prognosis have been fairly good in the reported cases, some have resulted in various states of blindness. As for etiology of optic neuritis in our patient, ischemic change of optic nerves due to microvasculopathy as well as slight demyelinating process were speculated by the VEP pattern.

Adolescent↗

PubMed1989

[Coronary endarterectomy].

From July, 1984, to December, 1986, coronary bypass grafting was performed in 314 patients, 70 (22%) requiring coronary endarterectomy (RCA; 48 pts, LAD; 10 pts, LAD + RCA; 10 pts, Others; 2 pts). Coronary endarterectomy patients (END group) were younger and often with the risk factor of hyperlipidemia than non-endarterectomy patients (NON group). The over-all hospital mortality rate of END group was 7 per cent; perioperative myocardial infarction occurred in 7 per cent of patients. Early postoperative angiogram (4 weeks after the operation) was performed in 54 patients. The patency rate of RCA endarterectomy was 81.8 per cent, and that of LCA endarterectomy was 75 per cent. This result was poor compared with the patency rate of non-endarterectomy graft (86.6%). However without endarterectomy, with all likelihood the patency rate of those grafts would have been poorer. The results of right coronary endarterectomy are satisfactory and better than those of the left coronary artery system. This experience suggests that coronary endarterectomy is safe and an useful adjunct of saphenous vein bypass grafting procedures in the management of diffuse coronary disease, especially in RCA lesions.

Adult↗

PubMed1989

[Role of endosalpinx in the oviductal environment].

The oviducal fluid and serum samples from rabbits were obtained daily during estrus and pseudopregnancy and were analyzed for electrolytes, steroid hormones and prostaglandins (PGs). The oviducal fluid volume reached its maximum (1.72 +/- 0.39 ml/day) 48 hours after hCG exposure and then declined gradually. Although the ratios of Na+/K+ and Ca++/Mg++ in the oviducal fluid did not change substantially throughout the observation period, the levels of K+ in the oviducal fluid were consistently 2.5 times greater than those in the serum. The concentrations of progesterone in the oviducal fluid were significantly smaller than those found in the serum. The levels of estradiol in the oviducal fluid were consistently elevated above the serum levels. The concentrations of PGF2 alpha in the oviducal fluid increased rapidly following ovulation and reached levels that were 10-14 times greater than those found in the estrus, whereas PGF2 alpha levels in the serum did not change significantly during the observation period. A significant difference between PGF2 alpha/PGE2 in the oviducal fluids (3.66 +/- 0.72) and serum (0.25 +/- 0.11) was observed at 24 hours after hCG. A surface morphologic study revealed a decrease in the number of ciliated cells, and an increase and expansion of secretory cells after hCG administration. The qualitative and qualitative differences between the oviducal fluid and serum suggest the involvement of secretory cells in the microenvironment for fertilization and preimplantation embryonic development.

Animals↗

PubMed1989

[Comparative studies on steroidogenesis and prostaglandins production by luteal cells in newly formed corpora lutea and early pregnancy].

The present study was undertaken to assess the ability of cultured luteal cells from human corpora lutea (CL) in the mid luteal phase and the early pregnancy to secrete steroids and prostaglandins (PGs). Luteal cells responded to hCG with a significant increase (2- to 4-fold) in progesterone (P) production. The addition of hCG to the culture media did not stimulate estradiol (E2) production. In contrast, both P and E2 secretion by luteal cells in early pregnancy were significantly lower than those found in the mid luteal phase. Exposure to hCG did not affect P production by luteal cells in early pregnancy. Arachidonic acid (AA) significantly stimulated PGE2 synthesis by luteal cells in the mid luteal phase in a dose-dependent manner. Both basal PGE2 production and the responsiveness to AA were maintained for the duration of the culture. However, hCG did not affect AA-stimulated PGE2 production. Both PGF2 alpha and 6-keto-PGF1 alpha production abruptly declined as the culture proceeded. PG synthesis by cultured luteal cells in early pregnancy was significantly lower than in the mid luteal phase. The ultrastructural characteristics of luteal cells in early pregnancy, which contained lipid droplets, granular and agranular endoplasmic reticulum and large spherical mitochondria, were maintained after 10 days in culture. The present results demonstrate that P and PGE2 production by cultured luteal cells predominate during the mid luteal phase. These data suggest that PGE2, but not PGF2 alpha, may be involved in the regulation of CL function in the menstrual cycle.

6-Ketoprostaglandin F1 alpha↗