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Biomedical subjects

T Asai

Publications and source records attributed to T Asai.

At least 343 records · Page 19Linked to original sources

Roles of ruvA, ruvC and recG gene functions in normal and DNA damage-inducible replication of the Escherichia coli chromosome.

Induction of the SOS response in Escherichia coli activates normally repressed DNA replication which is termed inducible stable DNA replication (iSDR). We previously demonstrated that initiation of iSDR requires the products of genes, such as recA, recB and recC, that are involved in the early stages of homologous recombination. By measuring the copy number increase of the origin (oriM1) region on the chromosome, we show, in this study, that initiation of iSDR is stimulated by mutations in the ruvA, ruvC and recG genes which are involved in the late stages of homologous recombination. Continuation of iSDR, on the other hand, is inhibited by these mutations. The results suggest that Holliday recombination intermediates, left on the chromosome due to abortive recombination, arrest replication fork movement. Low levels of iSDR and sfiA (sulA) gene expression were also observed in exponentially growing ruvA, ruvC and recG mutants, suggesting that the SOS response is chronically induced in these mutants. We propose that replication forks are arrested in these mutants, albeit at a low frequency, even under the normal (uninduced) conditions.

Bacterial Proteins↗

Intra-ocular pressure changes in patients with glaucoma. Comparison between the laryngeal mask airway and tracheal tube.

We performed a randomised prospective study in 20 patients with glaucoma to examine the effects of tracheal intubation and laryngeal mask insertion on intra-ocular pressure, mean arterial blood pressure and heart rate. After induction of anaesthesia with propofol, intra-ocular pressure decreased significantly below baseline values in both the laryngeal mask and tracheal tube groups. After insertion of the laryngeal mask, intra-ocular pressure remained significantly below baseline values in all patients. In contrast, tracheal intubation was associated with a significant increase in intra-ocular pressure to above baseline values in three out of eight patients. Insertion of the laryngeal mask had minimal effects on mean arterial blood pressure and heart rate, whereas tracheal intubation significantly increased both factors relative to pre-intubation values.

Adolescent↗

Use of the laryngeal mask for fibrescope-aided tracheal intubation in an awake patient with a deviated larynx.

I report a case in which fibrescope-aided awake tracheal intubation was achieved using a laryngeal mask, in a patient with a mediastinal goitre in whom tracheal intubation with both a laryngoscope and a fibreoptic bronchoscope had failed. The tumour extended to the upper part of the mediastinum. The larynx and the upper segment of the trachea were displaced by the tumour. Awake tracheal intubation with both a laryngoscope and a fibreoptic bronchoscope failed. The laryngeal mask was then inserted without difficulty. After a fibreoptic bronchoscope had been covered by a plastic tube, the combination was passed through the laryngeal mask into the trachea. The fibreoptic bronchoscope and the laryngeal mask were removed, and a reinforced endotracheal tube was then inserted over the plastic tube into the trachea. The time for tracheal intubation was about 70 s. The laryngeal mask may allow easier location of the laryngeal inlet with a fibreoptic bronchoscope, and this technique is a useful alternative to the conventional technique of tracheal intubation in the patient with a deviated larynx.

Aged↗

A multicenter, randomized, controlled trial of intravenous gamma globulin therapy in children with acute Kawasaki disease.

We studied the effect of intravenous, polyethyleneglycol-treated, human immunoglobulin, administered at 200 mg/kg per day (group A: n = 147; male 86, female 61; age < 1 year, 50) or 400 mg/kg per day (group B: n = 152; male 87, female 65; age < 1 year, 52) for five consecutive days and compared it with freeze-dried, sulfonated human immunoglobulin [group C: n = 152; male 87, female 65; age < 1 year, 51), administered at 200 mg/kg per day for five consecutive days, on the prevention of coronary artery abnormalities in Kawasaki disease. Echocardiograms were interpreted blindly and independently. Proportions of 87.1%, 95.4%, and 82.3% in groups A, B, and C, respectively, had no coronary artery abnormalities. The confidence limits of difference between the proportions of groups A and C, groups B and C, and groups B and A were -4.4% and 10.4%, 7.8% and 15.9%, and 4.0% and 10.8%, respectively. Duration of fever and serum immunoglobulin G (IgG) levels were correlated with the prevalence of coronary artery abnormalities. We concluded that intravenous, polyethyleneglycol-treated, human immunoglobulin and freeze-dried, sulfonated human immunoglobulin had clinically equivalent effects on coronary artery abnormalities, and that five daily doses of 400 mg/kg of intravenous, polyethyleneglycol-treated, human immunoglobulin is more effective than that of 200 mg/kg gamma globulin.

Acute Disease↗

Separation and characterization of a novel isoenzyme of cyclic nucleotide phosphodiesterase from rat cerebrum.

Anion-exchange chromatography on a Mono-Q column of the supernatant fraction, after ultracentrifugation, from a homogenate of rat cerebrum, prepared under isotonic conditions in the presence of protease inhibitors, yielded a novel isoenzyme of cyclic nucleotide phosphodiesterase (PDE) with properties unlike those of known PDEs. The isoenzyme was insensitive to stimulation by Ca2+/calmodulin and cyclic GMP, and it hydrolyzed both cyclic AMP and cyclic GMP with KM values of 0.109 +/- 0.008 microM and 1.78 +/- 0.04 microM, respectively. The ratio of Vmax of hydrolysis of cyclic GMP to that of cyclic AMP was 1.90 +/- 0.07. Nicardipine (PDE I inhibitor), SK&F 94120 (PDE III inhibitor), rolipram (PDE IV inhibitor) and zaprinast (PDE V inhibitor) had very weak inhibitory effects on the PDE activity of the isoenzyme. These results suggest that the isoenzyme is a novel and previously unreported species of PDE, which we tentatively designate PDE VIII.

3',5'-Cyclic-AMP Phosphodiesterases↗

The RecF pathway of homologous recombination can mediate the initiation of DNA damage-inducible replication of the Escherichia coli chromosome.

DNA damage-inducible DNA replication in SOS-induced Escherichia coli cells, termed inducible stable DNA replication (iSDR), has previously been shown to require either the RecBCD or the RecE pathway of homologous recombination for initiation. Here, we demonstrate that recB recC sbcC quadruple mutant cells are capable of iSDR induction and that a mutation in the recJ gene abolishes the inducibility. These results indicate that the RecF pathway of homologous recombination can also catalyze iSDR initiation.

Bacterial Proteins↗

Partial splenic embolization for the treatment of chronic idiopathic thrombocytopenic purpura.

OBJECTIVE: The purpose of this study was to assess the effectiveness of partial splenic embolization in the treatment of chronic idiopathic thrombocytopenic purpura. SUBJECTS AND METHODS: Twenty-six patients with chronic idiopathic thrombocytopenic purpura underwent partial splenic embolization and were followed up for 6-61 months. The condition was refractory to steroids in 20 of 26 patients. The other six patients, in whom a response to steroids was shown, could not be withdrawn from steroid therapy because their platelet counts decreased with any decrease in steroid dose. Five of 26 patients underwent splenectomy after partial splenic embolization, and the other patients were followed up without medical treatment until platelet counts decreased below 3 x 10(10)/l. The therapeutic effect of partial splenic embolization was defined on the basis of the platelet count at the last follow-up after partial splenic embolization: complete response, greater than 10 x 10(10)/l; partial response, 5 x 10(10)/l to 10 x 10(10)/l; and no response, less than 5 x 10(10)/l without medication. RESULTS: Partial splenic embolization brought a complete response in seven (33%) of 21 patients, a partial response in eight (38%), and no response in six (29%). In four of five patients, who later underwent splenectomy, response to partial splenic embolization was coincident with the response to splenectomy. No serious complications occurred, but minor complications such as abdominal pain, fever, and nausea were observed in most patients. CONCLUSION: This study suggests that partial splenic embolization might be useful as an alternative to splenectomy in the treatment of chronic idiopathic thrombocytopenic purpura.

Adult↗

[Autologous bone marrow transplantation following high-dose busulfan and etoposide for a patient with non-Hodgkin's lymphoma].

A 26-year-old man was admitted to our hospital with cervical tumor and facial edema on July 8, 1991. Examination of chest X-ray and chest CT showed a bulky tumor in the mediastinum and pleural effusion. A pathological diagnosis of non-Hodgkin's lymphoma (diffuse large cell, immunoblastic type) was made by biopsy of the cervical lymph node. MACOP-B chemotherapy or other combination chemotherapy did not achieve complete remission. The man was given a preparative regimen consisting of busulfan at 16 mg/kg orally and 60 mg/kg of etoposide (Bu-Et); 30 mg/kg of etoposide was administered by continuous intravenous infusion for 12 hours on day-5 and day-4, before he received autologous bone marrow on February 20. He was then given 300 micrograms of G-CSF was given to him to accelerate recovery of hematopoiesis from one day after BMT. The neutrophil count to 500/microliters recovered on day 28, and residual tumors disappeared. Although moderate-grade stomatitis and nasal bleeding developed, these toxicities were controllable and no veno-occlusive disease resulted. Regimen-related toxicities of Bu-Et preparatory regimen have been generally considered to be severe, but continuous and separate administration of etoposide as reported in this case may be useful to reduce side effects of this preparatory regimen.

Adult↗

[Experience with multidrug chemotherapy for patients with head and neck malignant tumors--comparison between CP therapy and PTP therapy].

A combined chemotherapy regimen (CP chemotherapy) consisting of cisplatin (CDDP) and peplomycin (PEP) was employed to treat patients with head and neck malignant tumors. More recently, PTP chemotherapy added to CP chemotherapy with THP-adriamycin (THP-ADM) was employed. We proceeded to investigate the efficacy of these two chemotherapeutic regimens. The subjects of this study included 22 patients in the CP chemotherapy group (18 males and four females). The PTP chemotherapeutic regimen was administered to 23 patients (18 males and five females). The results showed response rates of 54.5% for the CP chemotherapeutic regimen and 60.9% for the PTP chemotherapeutic regimen. In both treatment groups, the response rate decreased as the disease stage increased. As adverse reactions to the chemotherapeutic regimens, nausea and vomiting occurred in 63.6% of the CP group and 69.6% of the PTP group. Leukopenia was detected in 18.2% of the CP group and 69.6% of the PTP group, while alopecia was seen only in the PTP group, at an incidence of 39.1%. Cardiotoxicity was not detected in either group.

Adult↗