481 research outputs found
Left ventricular function before and after diltiazem in patients with coronary artery disease
Left ventricular contraction, relaxation and diastolic mechanics were investigated before and after intravenous administration of 15 mg of diltiazem in 15 patients with coronary artery disease. High fidelity left ventricular pressure measurements were performed in all 15 patients, with simultaneous biplane cineangiography in 13. The time constant of left ventricular isovolumic pressure decay was calculated from the linear relation of left ventricular pressure and its rate of change with time (negative dP/dt). Frame by frame volume analysis through one cardiac cycle was completed to construct volume-time and pressure-volume curves before and after the administration of diltiazem.After diltiazem, left ventricular peak systolic pressure decreased from 124 to 113 mm Hg (p < 0.001), while left ventricular end-diastolic pressure and heart rate were not altered. Maximal positive dP/dt also remained unchanged. End-diastolic volume was not changed after diltiazem, but end-systolic volume increased from 48 to 52 ml/m2(p < 0.025); as a result, ejection fraction decreased slightly from 57 to 55% (p < 0.025). The time constant of left ventricular pressure decay and maximal negative dP/dt decreased from 58 to 54 ms (p < 0.025) and from −1,404 to −1,321 mm Hg/s (p < 0.025), respectively. Peak early diastolic filling rate increased from 621 to 752 ml/s (p < 0.01) in association with an increase in filling volume during the first half of diastole from 60 to 68% (p < 0.005). No consistent displacement of the diastolic pressure-volume curve was observed after diltiazem.This study indicates that diltiazem reduces afterload and depresses myocardial contractility in patients with coronary artery disease. In contrast, it improves left ventricular relaxation, which may contribute in part to the enhancement of early diastolic filling. However, left ventricular passive diastolic properties remain uninfluenced
内側大腿回旋動脈下行枝と貫通動脈の分布域に関する研究 : 第1貫通動脈が大腿方形筋の直下を通る1変異例を中心に
The authors encountered an anatomical variant in which the first perforating artery (FPA) emerged posteriorly immediately below the quadratus femoris muscle. Although the usual medial circumflexus/circumflex femoral artery (MCFA) was coexistent, the variant suggested an intermediate morphology between the FPA and the usual descending branch of the MCFA. Using the observations from 51 lower extremities, we examined configurations of these arteries with special reference to the territorial correlation, i. e., whether the descending branch of the MCFA shows complementary territorial relations with the FPA and, if so, whether there is an intermediate morphology between these two arteries. The MCFA consistently supplied a limited area of the posterior thigh, whereas the FPA varied independently in its territory but consistently was the most dominant of all arteries supplying the region. Consequently, the variant might occur as a result of a muscular variation, and the suggested intermediate morphology was not evident
Meiotic association between Spo11 regulated by Rec102, Rec104 and Rec114
Meiotic recombination is initiated by DNA double-stranded break (DSB) formation catalyzed by Spo11, a type-II topoisomerase-like transesterificase, presumably via a dimerization-mediated mechanism. We demonstrate the existence of in vivo interactions between Spo11 proteins carrying distinct tags, and the chromatin-binding and DSB activity of tagged Spo11 at innate and targeted DSB sites upon fusion to the Gal4 DNA-binding domain. First we identified the interaction between Spo11-3FLAG and Gal4BD-Spo11 proteins, and established that this interaction specifically occurs at the time of DSB formation. We then observed that presence of the Gal4BD-spo11Y135F (nuclease-deficient) protein allows Spo11-3FLAG recruitment at the GAL2 locus, indicative of the formation of a hetero-complex near the GAL2 UAS sites, but no formation of double- or single-strand breaks. Spo11 self-interaction around the GAL2 DSB site depends on other proteins for DSB formation, in particular Rec102, Rec104 and Rec114. Together, these results suggest that in vivo self-association of Spo11 during meiosis is genetically regulated. The results are discussed in relation to possible roles of Spo11 self-interaction in the control of the cleavage activity
ヒト免疫不全ウイルス1型アクセサリータンパク質Vprの機能解析
学位の種別:課程博士University of Tokyo(東京大学
Recurrent superior mediastinal primary hemangiopericytoma 23 years after the complete initial excision: a case report.
We describe here a patient with a recurrent hemangiopericytoma of the superior mediastinum 23 years after an initial complete resection. In the current biopsy specimen, the tumor cells were much more anaplastic than those seen 23 years ago. Although the patient was treated with chemotherapy, which consisted of ifosfamide and epirubicin, the tumor was unresponsive and he died 6 months later from disease progression. Careful long-term follow-up is mandatory for patients with hemangiopericytomas because recurrence with greater malignancy can develop following an extended disease-free interval.</p
Duration of Postoperative Fever as a Simple and Useful Prognostic Indicator in Gastric Cancer Patients
[Background] Postoperative inflammation is associated with cancer progression in several cancers. However, the prognostic significance of postoperative fever remains unclear in gastric cancer patients. [Methods] We enrolled 442 patients with a histopathological diagnosis of gastric adenocarcinoma who underwent curative surgery. [Results] The mean duration of postoperative fever ≥ 37°C was 8.7 days (range: 0–186 days) and significantly longer in patients with advanced gastric cancer, venous invasion, and open or total gastrectomy vs. patients with early gastric cancer (P = 0.0072), no venous invasion (P = 0.025), laparoscopic gastrectomy (P = 0.027), and either proximal or distal partial gastrectomy (P = 0.0015). Five-year overall survival rates were 69.5% vs. 83.6% in the prolonged postoperative fever group (≥ 6 days of ≥ 37°C) vs. the nonprolonged group (< 6 days of ≥ 37°C), respectively (P = 0.0008). In patients without Clavien-Dindo classification postoperative infectious complications grade ≥ 2, 5-year overall survival was 69.7% vs. 84.0% in patients with prolonged postoperative fever vs. those without, respectively (P = 0.0067). Five-year disease-specific survival was 85.9% vs. 93.1% in patients with prolonged fever vs. those without, respectively (P = 0.041). Multivariate analysis indicated that postoperative fever was an independent prognostic indicator. [Conclusion] Postoperative fever ≥ 37°C duration may be useful in predicting prognosis in gastric cancer patients
Influence of surgical arch reconstruction methods on single ventricle workload in the Norwood procedure
ObjectiveThe study objective was to evaluate various types of Norwood arch reconstruction methods and to show the factors that affect the cardiac workload of the single ventricle. The Norwood procedure is one of the most challenging congenital heart surgeries. Several aortic arch reconstruction techniques have been reported to avoid recoarctation, ensure coronary perfusion, and improve long-term outcomes. Inside the arch, complicated turbulent flow is generated; however, little is known about the cause of the disadvantageous inefficient flow and the surgical techniques to avoid it.MethodsWe created patient-specific computational hemodynamic models of 9 patients who underwent different types of arch reconstruction methods. Four patients had aortic atresia, and 5 patients had aortic stenosis. Flow profiles were defined by echocardiography data corrected with body surface area. Turbulent pulsatile flow was analyzed with the finite volume method. Flow energy loss was calculated to estimate cardiac workload, and wall shear stress was calculated to estimate vessel wall stiffness increase.ResultsRecoarctation and acute arch angles increased wall shear stress and energy loss. In the patients with aortic atresia, a longitudinal incision toward the descending aorta was effective in creating a smooth arch angle. In the patients with aortic stenosis, arch repair with the Damus-Kaye-Stansel procedure in a single anastomotic site was effective in creating sufficient anastomosis space and a smooth arch angle.ConclusionsCreation of a large anastomotic space and a smooth aortic arch angle reduced wall shear stress and energy loss, and should improve long-term cardiac performance after the Norwood procedure
Left ventricular systolic series elastic properties in aortic stenosis before and after valve replacement
In seven patients with aortic valve disease the time course of an auxotonic beat was compared with that of an isovolumetric beat produced by aortic cross clamping during open heart surgery. The rate of systolic stress rise (dS/dt; g·cm−2) of the isovolumetric beat at peak meridional wall stress (Sp; g·cm−2) of the auxotonic beat was determined by tipmanometry and simultaneous sonomicrometry and was found to be 87% of maximum dS/dt. In the second part of the study the stiffness index (k) was calculated in patients undergoing cardiac catheterisation according to: k = 0.87·(max·dS/dt)/Sp·Vcf, where Vcf = normalised midwall circumferential fibre shortening velocity (circ·s−1). In 22 patients, 10 controls and 12 patients with aortic stenosis before (pre) and after (post) valve replacement the systolic stiffness index k (circ−1) was determined using tipmanometry and frame by frame angiocardiography. Muscle fibre diameter and interstitial fibrosis were assessed from left ventricular endomyocardial biopsies. The systolic stiffness index k was 15 circ−1 in controls, 14 in preoperative patients with aortic stenosis and 12 (p<0.01 v controls) in postoperative patients. There was a significant correlation between k and muscle fibre diameter (r = 0.55; p<0.01) but not between k and interstitial fibrosis or ejection fraction. We conclude that systolic stiffness index k is normal despite marked left ventricular hypertrophy in preoperative patients with aortic stenosis. Following successful valve replacement systolic stiffness index decreased and was significantly lower than in controls. Series elasticity appears to be determined by structures related to the muscle cell rather than to interstitial fibrosi
Radioligand Assay-Based Detection of Antibodies against SARS-CoV-2 in Hospital Workers Treating Patients with Severe COVID-19 in Japan.
This study aimed to clarify whether infection by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is prevalent among the staff of a hospital providing treatment to patients with severe coronavirus disease 2019 (COVID-19) using radioligand assay (RLA). One thousand samples from the staff of a general hospital providing treatment to patients with severe COVID-19 were assayed for SARS-CoV-2 nucleocapsid protein (N) IgG using RLA. Nine patients with COVID-19 who had been treated in inpatient settings and had already recovered were used as control subjects, and 186 blood donor samples obtained more than 10 years ago were used as negative controls. Four of the 1000 samples showed apparently positive results, and approximately 10 or more samples showed slightly high counts. Interestingly, a few among the blood donor samples also showed slightly high values. To validate the results, antibody examinations using ELISA and neutralizing antibody tests were performed on 21 samples, and chemiluminescence immunoassay (CLIA) was performed on 201 samples, both resulting in a very high correlation. One blood donor sample showed slightly positive results in both RLA and CLIA, suggesting a cross-reaction. This study showed that five months after the pandemic began in Japan, the staff of a general hospital with a tertiary emergency medical facility had an extremely low seroprevalence of the antibodies against SARS-CoV-2. Further investigation will be needed to determine whether the slightly high results were due to cross-reactions or a low titer of anti-SARS-CoV-2 antibodies. The quantitative RLA was considered sensitive enough to detect low titers of antibodies
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