Hiroaki Urayama

Enhanced Embryonic Nonmuscle Myosin Heavy Chain Isoform and Matrix Metalloproteinase Expression in Aortic Abdominal Aneurysm With Rapid Progression

Abdominal aortic aneurysms (AAAs) are characterized by structural deterioration of aortic wall leading to progressive dilatation. The histopathological changes in AAAs are particularly evident within the elastic media, which is normally comprised mainly of vascular smooth muscle cells (SMCs). There are vascular myosin heavy chain (MHC) isoforms; SM2 is specifically expressed in differentiated SMCs and SMemb is a nonmuscle-type MHC abundantly expressed in SMCs of the fetal aorta with an immature phenotype. Although AAA altered expression of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs), pathophysiological role of SMC phenotypic modulation in the AAA progression remains uncertain. To determine whether phenotypic modulation in vascular SMCs contributes to arterial medial degeneration, we examined MHC expression in SMCs of AAA. Aortic specimens were obtained from patients with slowly progressed AAA (n = 12) and rapidly progressed AAA (n = 5), and compared with normal aortic tissue (n = 3). Immunohistochemical staining was performed for detection of SMemb, SM2, MMP (types 2 and 9) and TIMP (types 1 and 2). Faint SMemb and abundant SM2 were observed in normal aorta, while the balance shifted to SMemb predominance in AAAs. Compared with slowly progressed AAA tissue, rapidly expanded AAA tissue demonstrated marked increases in SMemb expression with suppressed SM2. Predominant SMemb expression indicates presence of phenotypic modulated SMCs and enhanced MMP; while abundant TIMP was seen in mature SMCs expressing SM2. SMemb expression is markedly increased in AAA with MMP enhancement, and a significant imbalance between SMemb and SM2 results in rapid progression of AAA.

Incomplete Ventricular Septal Rupture Following Blunt Chest Trauma: A Case Report

This report describes a case of traumatic incomplete rupture of the ventricular septum, a rare complication caused by blunt chest trauma. Although a serial ECG progressed its course similar to acute anteroseptal myocardial infarction in this case, there was little clinical clue of septal tear. The diagnosis was established by transthoracic echocardiography. The authors chose a conservative line of management rather than surgical repair for incomplete septal rupture because of the patent’s stable clinical course and hemodynamic status. A sequence of echocardiography during a 32-day stay in the hospital showed no change in the extent of incomplete septal rupture, septal structure, systolic function, and shape of left ventricle and also obtained no evidence of shunting through the rupture. In conclusion, echocardiography is a useful investigation to make a diagnosis as well as for follow-up in case of incomplete ventricular septal rupture. A close follow-up of incomplete septal rupture with serial echocardiography should be performed, because several cases of delayed ventricular septal rupture following blunt chest trauma have been reported.

Increasing Circulation in the Lower Limb Under General Anesthesia Using the A-V Impulse System

The action of foot impulse technology (FIT) in reducing the risk of deep vein thrombosis (DVT) is well established. We hypothesized that intraoperative use of FIT devices will be effective in the prophylaxis of DVT. The aim of this study was to investigate the effect of a FIT device (A-V impulse system) on the venous flow of the lower extremity using duplex ultrasound scanning while the patient was under general anesthesia. Thirteen surgical patients who had no lower limb vessel lesions were selected for the study. Duplex scanning was used to measure blood velocity in the right common femoral vein, with and without the foot pump, before and during general anesthesia. The mean resting velocity was 33.2 ±5.5 cm/sec in the pre-anesthetic state, 32.1 ±4.2 cm/sec under anesthetic, and 30.4 ±5.0 cm/sec postoperatively. The peak velocities with the pump active were 38.6 ±5.0 cm/sec before anesthetic, 54.6 ±5.9 cm/sec while anesthetized, and 52.7 ±7.8 cm/sec postoperatively. The measured increases while under anesthesia and postoperatively both reached statistical significance (p < 0.05). Our study demonstrated that use of the A-V impulse system causes a statistically significant increase in venous velocity of the lower extremity while the patient is under general anesthesia.

Free radicals in reperfusion injury after acute aortic occlusion

This investigation aims to evaluate the role of free radicals and the influence of radical scavengers in reperfusion injury of the skeletal muscle in male Wistar rats. Various parameters, including tissue blood flow, serum and calf muscle tissue levels of thiobarbituric acid (TBA) reactants, and the water content of calf muscles, were measured in the experimental setting, where infrarenal abdominal aorta was occluded for two hours followed by reperfusion with and without intraperitoneal administration of radical scavengers (superoxide dismutase or catalase). The rats were divided into four groups: group A: single laparotomy; group B: two-hour occlusion; group C: two-hour occlusion with superoxide dismutase; group D: two-hour occlusion with catalase. The increases in both serum and calf muscle tissue levels of TBA reactants following reperfusion were diminished in groups C and D as compared with those in group B. The water content of calf muscles showed a significant increase after reperfusion in group B, whereas it did not change in group D. The calf muscle tissue blood flow after reperfusion was significantly lower in group C than that in group B. These results indicate that oxygen-derived free radicals may be responsible for reperfusion injury in the lower extremity and that the attenuated blood flow during reperfusion produced by these scavengers seems to play an important role in reducing lipid peroxidation . In a clinical setting, limiting the rate of reperfusion blood flow may reduce the reperfusion injury in skeletal muscle.

A Case Report of Frequent Familial Aggregation of Polycystic Liver Disease.

心窩部膨満感および上腹部腫瘤を主訴とする48歳の女性の多発性肝嚢胞症に対して, 1985年に嚢胞壁前壁切除術と開窓術を施行した.ひき続き本症例の姉も多発性肝嚢胞で当科にて同様の手術を行った.家族歴を詳細に調べたところ家系内に疑診者1名を含め計7名の多発性肝嚢胞症の集積を認めた.本家系のように濃厚な本症集積例の報告はまれである.遺伝様式の追究も含め嚢胞性疾患の家系内調査は必ず行うべきと考える.さらに本症例は初回手術3年後に, 症状が再燃し画像診断上も遺残嚢胞の増大と嚢胞壁前壁切除部の腹壁との癒合を認めたため, 超音波誘導下嚢胞内純エタノール注入療法が行われた.約10個の嚢胞に対しておのおの1～4mlのエタノールを注入し再排液しない方法で行ったが, 今日まで嚢胞は縮小したままである.類似症例に対して本法を積極的に行うつもりである.

The Role of Neostigmine in Development of Acute Gastric Mucosal Lesion in Dogs with Live Bacterial Flora-Induced Shock

SummaryThe factors that frequently cause the development of acute gastric mucosal lesions (AGML) were studied in 37 mongrel dogs. Bacterial shock was induced by bolus injection of E. coli live bacterial flora (1010 cells/kg body weight) under parietal cell-stimulated condition by intravenous administration of 0.008 mg/kg per hour of pentagastrin. In addition, 0.01 mg/kg per hour of neostigmine sulfate was administered intravenously during the experiment. Frequent development of AGML was observed in the neostigmine-administered canines without significant changes in the gastric corporal and antral tissue blood flow. In the neostigmine-administered group, AGML was observed in the antrum, although in the other group AGML was mostly observed in the corpus. These results suggest that a neostigmine-induced systemic vagostimulated condition by intravenous administration of neostigmine plays an important role in the development of AGML in dogs subjected to bacterial shock.