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Biomedical subjects

M Takao

Publications and source records attributed to M Takao.

At least 145 records · Page 8Linked to original sources

[Percutaneous nephrolithotomy in horseshoe kidney].

Two patients with renal pelvic stone in a horseshoe kidney who underwent a percutaneous nephrolithotripsy (PNL) are presented. Case 1 was a 36-year-old man with a 20 x 12 mm right renal pelvic stone in a horseshoe kidney. Case 2 was a 47-year-old man who had been followed up at our clinic for a horseshoe kidney and was found to have a 15 x 10 mm left renal pelvic stone. We found that percutaneous removal of renal pelvic stones can be performed safely in a horseshoe kidney. It appears that to remove stones from the renal pelvis in a horseshoe kidney 4 items must be considered. 1) The anatomical relationships of the horseshoe kidney to other viscera and blood vessels should be confirmed before surgery utilizing computerized tomography or ultrasound sonography. 2) The occlusion ureteral catheter should be inserted up to the renal pelvis to prevent small fragments from falling into the ureter. 3) The rigid nephroscopy should be introduced through the most appropriate calyx, so that its manipulation could be limited. 4) The fragmentation of stones should be performed from the peripheral surface of a stone to prevent from migrating into another calyx. We believe this is only the sixth and seventh documented cases involving a horseshoe kidney.

Adult↗

Characterization of a superoxide dismutase gene from the archaebacterium Methanobacterium thermoautotrophicum.

A gene encoding superoxide dismutase (SOD) was cloned from the archaebacterium Methanobacterium thermoautotrophicum, the first example from an anaerobic bacterium. The deduced amino acid sequence showed overall similarity to sequences of known Mn- and Fe-SODs from aerobic organisms. Judging from a detailed sequence comparison, the cloned SOD gene is classified as Mn-SOD. By comparison of Mn-SOD sequences among various species it was suggested that archaebacterial superoxide dismutase is a direct descendant of a primordial enzyme. Between a putative promoter and the start codon there is an inverted repeat sequence which is also found in the counterpart of Halobacterium halobium.

Amino Acid Sequence↗

Increased UV sensitivity of Escherichia coli cells after introduction of foreign photolyase genes.

High-expression plasmids for photolyase (phr) genes from the bacteria Escherichia coli, Anacystis nidulans, Streptomyces griseus and Halobacterium halobium and the yeast Saccharomyces cerevisiae were constructed and introduced into E. coli phr recA cells. As previously reported, al introduced phr genes provided the host cells with photoreactivation-repair activity and the introduced E. coli phr gene rendered the host cells more UV-resistant in the dark. E. coli cells harboring foreign phr genes, however, were found to be more sensitive to UV light in the dark than cells containing the vector plasmid only. These differences in UV sensitivity in the dark disappeared when the host cells had an additional mutation, uvrA, suggesting that the foreign photolyases inhibited the E. coli excision-repair system.

Base Sequence↗

[Evaluation of aortocoronary bypass operation using a He-Ne laser flowmeter--comparison between internal mammary artery grafts and saphenous vein grafts].

It was very difficult to measure myocardial blood flow in clinical cases. Recently, a He-Ne laser doppler flowmeter was developed, and we made it possible to measure the pre-and post-operative myocardial blood flow in cases of coronary artery bypass grafting (CABG). We applied a laser flowmeter to 30 cases of bypass grafting to the left anterior descending coronary artery (18 cases with IMAG and 12 cases with SVG). The preoperative myocardial blood flow at the right ventricular anterior wall was 77 +/- 15 ml/min/100 gr, and the postoperative flow at the same point was 81 +/- 12 ml/min/100 gr. There was no significant change between the pre-operative value and the postoperative one. Myocardial blood flow at the left ventricular anterior wall in SVG group significantly increased from the preoperative value of 58 +/- 11 ml/min/100 gr to the postoperative value of 86 +/- 9 ml/min/100 gr (p less than 0.001). In IMAG group, myocardial blood flow at the left ventricular anterior wall similarly increased from 73 +/- 14 ml/min/100 gr to 83 +/- 15 ml/min/100 gr (p less than 0.01). The postoperative value of IMAG group was almost equal to the value of SVG group. The increased rate of myocardial blood flow at the left ventricular anterior wall was 52 +/- 32% in SVG group and 18 +/- 12% in IMAG group. These rates were obviously distinguished from the increased rate at the right ventricular anterior wall.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

[Steroid withdrawal in renal transplant recipients].

The clinically important side effects of long-term steroid use are well known. We report the results of complete steroid withdrawal in 7 living-related renal transplants in HLA-identical (3) or one-haplotype match (4) recipients initially treated with azathioprine (5) or cyclosporine (2), and steroids. After the end of the second year, steroids were stopped if renal function was normal (serum creatinine below 2.0 mg/dl) and if no alterations were seen on renal biopsy. In 1 patient steroid had to be discontinued because of the complications of steroid immunosuppression. The study population consisted of 7 patients with a mean age of 32.4 years. The sex distribution was 6 males and 1 female. All patients had received a minimum of 3 blood transfusions prior to transplantation. Steroid was discontinued 34.0 +/- 18.1 months posttransplant. Oral azathioprine or cyclosporine were employed for long-term maintenance immunosuppression. Six patients (86%) have remained continuously off steroids for 52.2 +/- 50.5 months (range 4-150) with stable renal function. The mean serum creatinine was 1.1 +/- 0.4 mg/dl at the most recent follow-up. Reinstitution of steroid was required in 1 patient (14%) for rejection (36 months after steroid withdrawal). Thus, steroid withdrawal was successful in 6 of 7 patients. In HLA-identical recipients, all are currently steroid-free. In haplo-matched patients, 75% are steroid independent. Discontinuation of steroid resulted in a decrease in serum cholesterol concentration from 246 +/- 41 to 204 +/- 25 mg/dl (P less than 0.003). We conclude that steroid withdrawal may be accomplished in selected patient without increasing the rate of graft loss.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Absorption of tetrahydropyranyl adriamycin administered intravesically immediately after transurethral resection of bladder carcinoma].

Absorption of tetrahydropyranyl adriamycin (THP) administered immediately after transurethral resection of bladder carcinoma (TUR-Bt) has not been reported. In this study, we have examined the absorption of THP and the systemic toxicity in the early post-TUR period. Of 21 patients with bladder carcinoma, 10 had a solitary tumor and 11 multiple tumors. Twenty mg THP in 40 ml of sterile water was intravesically administered on days 1, 3, 5, 7, 14 and 28, and then every 4th week. The THP solution was retained for 2 hours. The blood THP concentration was measured 30 minutes and 2 hours after the intravesical administration on days 1, 7 and 28. No systemic side effects were observed. Thirteen of the 38 (34%) samples contained a detectable level (more than 1 ng/ml) of THP on the post-TUR-Bt on day 1, 8, of 42 (19%) on day 7, and 3 of 18 (17%) on day 28. Altogether, 24 of the 98 (24%) samples contained more than 1 ng/ml THP. The highest blood THP level was 23 ng/ml on day 1. The differences between frequency of detection of blood THP in the samples at 30 minutes and 2 hours were not statistically significant. The difference between average concentration of blood THP of patients with solitary and multiple tumors also was not significant. These results indicate that intravesical THP administration starting within 24 hours after TUR-Bt can not result in significant systemic absorption of THP, and the systemic toxicity can be avoided.

Absorption↗

[Surgical treatment and long-term results of aneurysms of Valsalva sinus in 24 cases].

Twenty-four patients with aneurysm of Valsalva sinus were surgically repaired over a 23 year period (1965-1988). These patients were ranged 2 to 54 years of age and eleven of them were male. Rupture of aneurysm of Valsalva sinus was combined with aneurysm in 20 cases, ventricular septal defect in 12 cases and aortic regurgitation in 6 cases. At present, our routine operative procedure for ruptured aneurysm is direct closure of the defect with patch closure of aneurysm after resection of the aneurysm, but when the diameter of aneurysm is smaller than 7 mm, direct closure of the defect of the aneurysm was used. Only one patient after patch closure of ruptured sinus of Valsalva (Konno type I) required reoperation for penetration into left ventricle. This case might be avoided if patch was sutured to annulus of aortic valve. There were two operative death and one late death. The former died of cerebral infarction and low output syndrome, the latter died of sepsis. The mean follow-up period (+/- standard deviation) was 8.2 +/- 6.0 years. All patients that were followed were thirteen and found to be in New York Heart Association class I.

Adolescent↗

Molecular characterization of a gene encoding a photolyase from Streptomyces griseus.

By using a synthetic DNA probe derived from an amino acid sequence in the most conserved region of three known photolyases (Escherichia coli, Anacystis nidulans and Saccharomyces cerevisiae), we isolated a DNA fragment containing two long open reading frames (ORFs) from a genomic DNA library of Streptomyces griseus. One ORF encodes a polypeptide of 455 amino acids (Mr 50594), which exhibits substantial similarities with the other three photolyases. Photoreactivation-repair deficient E. coli cells could be converted into photoreactivatable ones by introduction of plasmids harboring this ORF, indicating that this is the photolyase gene of S. griseus. The deduced aa sequence of Streptomyces photolyase was most similar to that of E. coli. The putative DNA binding site as well as cofactor binding regions were proposed.

Amino Acid Sequence↗

Alterations in coagulation and fibrinolysis associated with cardiopulmonary bypass during open heart surgery.

The effect of heparin as an anticoagulant was examined and the extent of fibrinolytic activity during cardiopulmonary bypass (CPB) was measured. Twenty patients undergoing valve replacement or aortocoronary bypass surgery were studied. Fibrinopeptide A (FPA) levels gradually became elevated as CPB proceeded, and antithrombin III (AT III) decreased during CPB. This indicates that despite the use of heparin, the coagulation system was activated, leading to fibrin formation in the microcirculation. On the other hand, fibrinopeptide B (FPB beta 15-42) also increased to four times the preoperative value at two hours on CPB. Intrinsic fibrinolytic activity, as determined by the activity of kaolin-activated euglobulin, was transiently increased only at the beginning of CPB. The C1 inactivator-resistant fibrinolytic activity and tissue plasminogen activator antigen (t-PA;Ag) increased sharply during CPB and reached maximum levels one hour after the start of CPB, indicating that enhanced fibrinolytic activity during CPB is predominantly of extrinsic origin as the result of t-PA release from the vascular walls. It is concluded from the above findings that thrombin activity continues during CPB. Enhanced fibrinolytic activity during CPB appears to be important because t-PA activates plasminogen predominantly where fibrin is formed, leading to dissolution of the microthrombi formed during CPB.

Adult↗

Expression of an Anacystis nidulans photolyase gene in Escherichia coli; functional complementation and modified action spectrum of photoreactivation.

The Anacystis nidulans photolyase gene inserted in an expression vector plasmid was introduced into Escherichia coli cells and the production of Anacystis photolyase protein was confirmed by reaction with antibodies raised against photolyase purified from A. nidulans cells. The Anacystis photolyase functioned in photoreactivation repair defective E. coli cells. The E. coli transformants exhibited an action spectrum with a maximum around 380 nm similar to that of E. coli photolyase in contrast with the action spectrum of A. nidulans cells which has a maximum at 437 nm. These results indicate that the Anacystis photolyase produced in E. coli cells has enzymatic activity in spite of the apparent lack of its intrinsic 8-hydroxy-5-deazaflavin cofactor.

Base Sequence↗

Tandem arrangement of photolyase and superoxide dismutase genes in Halobacterium halobium.

A DNA fragment containing the photolyase gene was cloned from Halobacterium halobium. The deduced amino acid sequence is highly similar to those of four known photolyases from eubacteria and a eucaryote. The cloned gene expressed in Escherichia coli increased the survival of UV-irradiated host cells by photoreactivation. These results indicate that photolyases of eucaryotes, eubacteria, and archaebacteria are derived from a common origin. In this cloned DNA fragment, two additional open reading frames (ORFs), ORF 151 and ORF 200, were found in the 5' and 3' adjacent flanking regions of the photolyase gene. ORF 200 shows unequivocal amino acid sequence homology to all known manganese and iron superoxide dismutases. Northern (RNA) hybridization analysis of H. halobium RNA revealed the existence of three transcripts, one of which covered all three ORFs, indicating that photolyase and superoxide dismutase are partly cotranscribed in this bacterium.

Amino Acid Sequence↗

[Surgical treatment of left ventricular aneurysm associated with mitral regurgitation].

The purpose of this study is to analyze the early and late results of left ventricular aneurysmectomy in patients with mitral regurgitation secondary to myocardial infarction. Twenty patients who had left ventricular aneurysm combined with mitral regurgitation underwent the isolated or combined aneurysmectomy during the last 10 years. There were 18 male cases and 2 female cases, and their age ranged from 31 to 64 (mean age 52.6 years). In 19 cases, the left ventricular aneurysm were caused secondary to antero-septal infarction due to the occlusion of the left anterior descending coronary artery. In one case, the coronary spasm of circumflex artery provoked the posterolateral myocardial infarction and the tendon rupture of posterior papillary muscle. The isolated left ventricular aneurysmectomy were performed in 6 cases and the combined operations were coronary artery bypass grafting in 11 cases, mitral annuloplasty in 1 case, mitral annuloplasty and bypass grafting in 1 case, and mitral replacement in 1 case. There were no operative death cases. The preoperative mean functional class (NYHA classification) was 2.9 and the postoperative class was 1.4. The preoperative mitral regurgitation of grade 1 in Sellers' classification was observed in 11 cases. Grade 2 regurgitation was observed in 6 cases, grade 3 in 2 and grade 4 in 1. After surgery, mitral regurgitation more than grade 2 was recognized in 3 cases (group A) and regurgitation less than grade 1 was seen in 17 cases (group B).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Radiographic evaluation of blunt renal trauma.

Radiographic evaluation was performed on 18 patients with blunt renal trauma. Of 18 patients 11 had minor injury. Four of 11 patients with minor injury had a normal intravenous pyelogram (IVP), and other 7 were confirmed to have minor renal injury by computed tomographic (CT) scan. Seven patients had major injury. Six patients were diagnosed by both IVP and CT, and five by angiography. CT scan was reliable in major injury and had the high staging accuracy. Angiography was useful in specific patients. Therefore, we conclude that IVP or CT scan should be performed as the initial evaluation, and CT scan or angiography might be used as the second examination in selected patients.

Adolescent↗

[Serum uptake of doxorubicin intravesically administered soon after transurethral resection of bladder carcinoma].

To obtain the maximum prophylactic effect of intravesical chemotherapy on the bladder tumor recurrence treatment should be started early. Since 1983, we have been initiating prophylactic instillation of doxorubicin hydrochloride (DXR) on the first post-transurethral resection (TUR) day. This study was conducted to define serum uptake of DXR and systemic toxicity in the early post-TUR period. Fifteen TURs were carried out on 14 patients with superficial bladder carcinoma. DXR (30 mg) in normal saline (30 ml) was intravesically administered 1, 3, 5, 7 and 14 days after TUR, and every 4 weeks thereafter. DXR solution was kept in the bladder for 2 hours. The serum DXR concentration was measured 30 minutes and 2 hours after the instillation through 1 to 5 days after TUR. Intolerable vesical irritability was seen in 4 of 60 instillations. No systemic side effects, however, were observed. Three of 24 samples contained a detectable level (10 ng/ml) of DXR on the post-TUR day 1, 6 of 22 samples on the post-TUR day 3, and 6 of 14 samples on the post-TUR day 5. Overall, 15 of 60 samples contained more than 10 ng/ml DXR. The highest serum DXR level was 47 ng/ml at the post-TUR day 1. Frequency of detection and average levels of serum DXR in 30-minute and 2-hour samples were not significantly different. Average concentrations in patients with multiple or diffuse tumor and solitary tumor were also not significantly different. These results indicate that intravesical instillation starting within 24 hours after TUR does not produce significant serum uptake of DXR, and systemic toxicity can thereby be avoided.

Administration, Intravesical↗

Cloning and characterization of a photolyase gene from the cyanobacterium Anacystis nidulans.

A 2 kb fragment was isolated from an Anacystis nidulans genomic DNA library by hybridization with synthetic oligonucleotide probes derived from the N-terminal amino acid sequence of Anacystis photolyase. This fragment contains a 1452 bp-long open reading frame encoding a polypeptide of 484 amino acids (Mr 54475). Antibodies raised against purified Anacystis photolyase reacted with extracts of cells harboring fused genes between lacZ of Escherichia coli and this gene. A 40.7% similarity was found between the deduced amino acid sequences of Anacystis and E. coli photolyases, notwithstanding the difference in chromophore structure.

Amino Acid Sequence↗

Isolation and sequence determination of the chicken rhodopsin gene.

A chicken genomic library was screened with a bovine opsin cDNA probe. A clone isolated under high stringency hybridization conditions contained DNA sequences highly homologous to all of the five exons of bovine and human opsin genes. Sequence comparison of the putative open reading frame in the chicken DNA fragment of 4.3 kb with bovine opsin cDNA revealed 82% identity for the nucleotide and 87% for the deduced amino acid sequence, indicating that this DNA fragment contains the complete chicken opsin gene. The position of four introns and amino acid sequences at all putative cytoplasmic loops are exactly conserved in chicken and mammals.

Animals↗