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ObjectiveThis study was undertaken to identify preoperative and intraoperative risk factors influencing outcome after operations requiring hypothermic circulatory arrest with selective antegrade cerebral perfusion in a single center.MethodsBetween November 1999 and March 2006, a total of 501 consecutive patients (median age 64 years, range 20–86 years, 320 male) underwent aortic arch surgery with moderate hypothermic circulatory arrest (25°C ± 2°C) and additional selective antegrade cerebral perfusion (14°C) at our institution for various indications (256 aneurysms, 153 acute and 23 chronic type A aortic dissections, 66 other). Of these, 181 were emergency operations. Statistical analysis was carried out to determine risk factors for 30-day mortality as well as for temporary and permanent neurologic dysfunction.ResultsOverall mortality was 11.6%. Permanent neurologic dysfunction occurred in 48 patients (9.6%); temporary neurologic dysfunction was detected in 67 patients (13.4%). Multivariate analysis revealed age (P = .001, odds ratio 1.08), reoperation (P = .006, odds ratio 3.58), femoral arterial cannulation (P = .004, odds ratio 2.87), and cardiopulmonary bypass duration (P < .001, odds ratio 1.009) as risk factors for mortality. Permanent neurologic dysfunction was associated with preoperative renal insufficiency (P = .029, odds ratio 2.79) and operation time (P < .001, odds ratio 1.005), whereas temporary neurologic dysfunction occurred in patients with coronary artery disease (P = .04, odds ratio 2.29), emergency surgery (P = .001, odds ratio 4.09), and increasing hypothermic circulatory arrest duration (P = .01, odds ratio 1.015).ConclusionModerate hypothermic circulatory arrest in combination with cold selective antegrade cerebral perfusion is an adequate tool for neuroprotection during aortic surgery. Nevertheless, the safety of this technique is limited for patients with long intraoperative durations, advanced age, and multiple comorbidities. This technique, which avoids profound core temperatures, has become an alternative to simple deep hypothermic circulatory arrest.

In order to clarify the structure-activity relationship of c-Ha-ras proteins (p 21 s) genes encoding p 21 (Val-12), p 21 (Leu-61) and p 21 (Arg-61) were synthesized by joining oligonucleotides with T 4 DNA ligase and expressed in E. coli under the regulation of E. coli tryptophan promoter. In addition, the gene for normal p 21 was constructed by cassette mutagenesis using restriction sites, ClaI-BssH II. The guanosine diphosphate (triphosphate) binding properties and guanosine triphosphatase (GTPase) activities of these p 21 s were examined. It was found that the guanine nucleotide binding abilities of all p 21 s produced in this study were relatively same but GTPase activity of activated p 21 s were significantly reduced.Furthermore, the gene encoding novel p 21 in which the guanine nucleotide binding sites was modified was synthesized by ligation of oligonucleotides and expressed in E.coli. Its biochemical activities are also discussed.

4～8mmの歯周ポケットを有する9名め成人性歯周炎罹患者について, プラークコントロール, 歯石除去及びルートプレーニングを施した。その前後にポケット底部より採取した細菌叢の変動を, グラム染色, 暗視野顕微鏡, 嫌気培養法を用いて検討した。その結果, 歯周初期治療後にグラム陽性球菌の増加とグラム陰性桿菌, 糸状菌の減少が認められた。また, 術前, プラークコントロール, 歯石除去とルートプレーニングの3時期において Fusobacterium 属は6.8%, 4.8%, 1.4%, Bacteroides 属は11.0%, 3.1%, 0.4%, Spirochetes は11.0%, 9.5%, 0.5%の変動を示した。black pigmented Bacteroides は7被検部位中3部位で, Fusobacterium necrophorum は7被検部位中5部位で検出された。Bacteroides はポケットの深さと, Spirochetes はポケットの深さ, 歯肉炎指数, プラークスコアとの間で各々有意な相関性が認められた。

Oxidized deoxyribonucleotides, 2-hydroxydeoxyadenosine 5'-triphosphate (2-OH-dATP) and 8-hydroxydeoxyguanosine 5'-triphosphate (8-OH-dGTP), were introduced into Escherichia coli strains deficient in DNA polymerase IV (a Y-family DNA polymerase encoded in the dinB gene), and the MutT and Orfl35 proteins to examine their in vivo roles in mutagenesis elicited by 2-OH-dATP and 8-OH-dGTP. 2-OH-dATP elicited mutations less efficiently in the dinB- strain than in the wild type strain, suggesting involvement of DNA polymerase IV in 2-OH-dATP-induced mutations. 8-OH-dGTP and 2-OH-dATP elicited mutations more efficiently in mutT- and orfl35- strains, respectively, than those in their isogenic mutT+ and orfl35+ strains. These results indicate that these proteins play important roles in mutagenesis induced by 2-OH-dATP and 8-OH-dGTP in vivo.

Introduction In DNA, 8-oxo-7,8-dihydroguanine (GO, 8-hydroxyguanine) is one of the most pivotal oxidatively damaged bases and induces G:C → T:A transversion mutations. DNA polymerase λ preferentially inserts dCTP opposite GOin vitro, and this error-free bypass function is considered to be important after A base removal from GO:A pairs by the MUTYH DNA glycosylase. To examine the effects of reduced levels of DNA polymerase λ on the GO-induced mutations, the polymerase was knocked-down in human U2OS cells, and a shuttle plasmid DNA containing a GO:C pair at position 122 in the supF gene was transfected into the cells. The plasmid DNA replicated in the cells was introduced into an Escherichia coli indicator strain, to measure the supF mutant frequency. Results The knockdown of DNA polymerase λ significantly enhanced the mutant frequency of the GO plasmid DNA. Contrary to our expectations, the knockdown did not promote the targeted G:C → T:A transversion. Instead, substitution mutations at G:C sites other than position 122 were enhanced in the cells. Conclusions These results suggested that the knockdown of DNA polymerase λ induced action-at-a-distance mutagenesis in human cells when the GO:C pair was present in the DNA.

Introduction Although encrusted stents may lead to some unwanted complications including urinary tract obstruction, urinary sepsis, and potential loss of kidney function, there is currently no consensus on the most efficient method for managing stents that are intentionally left in situ. This is the first report describing the management of an encrusted stent using combined endoscopic surgery in the prone split-leg position in a single session. Case presentation A 47-year-old Asian man presented with left flank pain and macrohematuria. The patient had undergone left ureteral stenting three years previously for the treatment of left ureteral stones and hydronephrosis; however, he was lost to follow-up before the treatment for the ureter stones was completed. Therefore, the ureteral stent and stones were not removed. An abdominal radiograph and a noncontrast computed tomography scan showed encrustation along the retained stent with stone burdens in the kidney and ureter. The ureteral stent could not be removed by cystoscopy after shock wave lithotripsy of the left ureteral stones. Therefore, endoscopic lithotripsy combined with flexible ureteroscopy and miniature nephroscopy was performed with the patient in the prone split-leg position. All the stones and the encrusted ureteral stent were successfully removed in a single session. Conclusions In this case, percutaneous nephrolithomy in addition to flexible ureteroscopy was preferred because severe encrustation of the proximal stent and ureteral stones complicated the therapeutic strategy. Combined endoscopic techniques in the prone split-leg position can achieve successful and safe management of encrusted stents.