Case of ruptured gastroduodenal arterial pseudoaneurysm with penetration to the duodenum, successfully treated with transcatheter arterial embolization]

A 77-year-old man, who underwent segmental pancreatectomy for intraductal papillary mucinous adenoma in 2001, was referred to our hospital with complaints of hematemesis and melena on January, 2004. Emergency upper gastrointestinal endoscopy showed a pulsating submucosal protrusion in the duodenal bulb, which was identified as a gastroduodenal arterial aneurysm measuring 1.5cm on abdominal CT imaging. Transcatheter arterial embolization of the aneurysm with metallic coils was successfully performed. Periodically repeated endoscopic examination has revealed the coils protruding into the duodenal lumen without any serious complication.     

Congenital pseudarthrosis of the tibia: analysis of the histology and the <Emphasis Type="Italic">NF1</Emphasis> gene

Background Congenital pseudarthrosis of the tibia (CPT) is frequently, but not always, associated with neurofibromatosis type 1 (NF1). Double inactivation of the NF1 gene has been reported to be the pathogenesis of CPT in NF1 cases. Methods We analyzed the loss of heterozygosity (LOH) of the NF1 gene in cases of CPT with NF1 to examine whether double inactivation was seen in the case. In addition to morphological analysis, immunoexpression of differentiation markers was examined. Results and discussion The tibia tapered with the zone phenomenon from mature to immature bone with osteoblastic rimming, resembling osteofibrous dysplasia. Osteosclerotic bowed bone with a small number of osteoclasts suggested dysfunction of bone remodeling. Fibrous tissue at the site of pseudarthrosis was associated with the periosteum and demonstrated myofibroblastic differentiation accompanied by massive cartilage formation, suggesting some misdirection during the differentiation of periosteum to myofibroblasts or chondrocytes. LOH of the NF1 gene locus was not seen in fibrous tissue. This result suggests that CPT is not accompanied by double inactivation in every NF1 case.     

Effects of Right Ventricular Failure on Renal Function During Pneumatic Left Ventricular Assist

Abstract: In an experimental dog model of acute biventricular failure, the effects of left ventricular (LV) assist on renal hemodynamics and function were evaluated. After the induction of severe cardiac failure by multiple ligation of the coronary arteries, LV assist with a 40 ml pneumatic pulsatile pump was initiated, and the aortic flow was maintained at control values. The right atrial pressure (RAP) rose to 21.3 mm Hg with the appearance of profound right ventricular (RV) failure. Renal arterial blood flow (RAF) decreased to about 60% of the control value after 2 h of LV assist. The urine volume decreased and renal function deteriorated progressively. RV assist decreased the RAP to 4.8 mm Hg, and the reduced RAF recovered. After 3 h of RV assist, the RAF returned to initial values and the urine volume increased, but renal function did not recover. Advanced biventricular failure with elevated RAP during LV assist reduced renal perfusion and impaired renal function and may be an indication for early RV assist     

Effects of sodium nitroprusside (MR7S1) and nitroglycerin on the systemic,renal, cerebral,and coronary circulation of dogs anesthetized with enflurane

Summary In beagle dogs anesthetized with enfluranenitrous oxide, effects of sodium nitroprusside (SNP; MR7S1) and nitroglycerin (NTG) on hemodynamics and main organ circulation were studied to evaluate their effectiveness and safety as hypotensive agents during anesthesia. SNP (MR7S1) infusion (1–10 g/kg/min) decreased arterial blood pressure in a dose-dependent manner. The hypotension was stable during the infusion. After discontinuation of infusion, the blood pressure rapidly returned to the initial level. The hypotension was associated with decreases in cardiac output and total peripheral resistance. NTG infusion (3–10 g/kg/min) decreased arterial blood pressure, too, but the hypotension was less marked and not dose dependent, and the recovery was slower. Neither drug changed the heart rate. Infusion of SNP (MR7S1) and NTG did not change the hypotension induced by the injection of adenosine, SNP, and NTG. Furthermore, cerebral blood flow, cerebral oxygen consumption, and renal blood flow were unchanged during the hypotension produced by either drug. Coronary blood flow was decreased, but this was due to decreases in cardiac oxygen consumption. In conclusion, SNP (MR7S1) is superior to NTG as a hypotensive agent during anesthesia in efficacy, clear dose dependency, and rapid recovery. The hypotension induced by NTG as well as SNP (MR7S1) seems to have no undesirable effects on the circulation of important organs.     

Effects of sevoflurane on autonomic nerve activities controlling cardiovascular functions in rats

Effects of different inspiratory concentrations of sevoflurane (fluorometyl-1,1,1,3,3,3,-hexafluoro-2-propylether) on blood pressure, heart rate and efferent activities of cardiac sympathetic, cardiac parasympathetic and renal sympathetic nerves were examined using rats either under the resting condition or during noxious mechanical stimulation of a hindpaw. Under the resting condition, an increase in the inspiratory concentration of sevoflurane from 2.1% to 4.2% gradually caused a decrease in blood pressure and heart rate. With the increase in the sevoflurane concentration, cardiac sympathetic nerve activity decreased, whereas renal sympathetic nerve and cardiac parasympathetic nerve activities did not change significantly. When noxious mechanical stimulation was applied to a hind-paw by pinching, blood pressure and heart rate, renal sympathetic and cardiac sympathetic nerve activities all increased at the 2.1% concentration of sevoflurane. The responses of these parameters were attenuated at the 3.1% concentration of sevoflurane and almost disappeared at the 4.2% concentration. Cardiac parasympathetic nerve activity did not change significantly during the pinching stimulation throughout the 2.1–4.2% concentration increase.(Kurosawa M, Meguro K, Nagayama T et al.: Effects of sevoflurane on autonomic nerve activities controlling cardiovascular functions in rats. J Anesth 3: 109–117, 1989)     

Technical quality evaluation of EEG recording based on electroencephalographers' knowledge

The aim of this study is to develop a technical quality evaluation system of electroencephalogram (EEG) recording in order to acquire technically satisfactory EEG records, which may contribute to the accuracy improvement of EEG interpretation. In our developed system, the evaluation of EEG recording comprises the detection of technical artifacts and physiological status, which indicates the recording status objectively. In addition, the caution signals to users are generated in the system according to the undesired status detected. The information displayed to users includes the updated EEG records and instant evaluation results. Two examples of evaluation results are introduced in this paper, illustrating unsatisfactory records and artifact free records, respectively. The experimental results are proposed to verify the effectiveness of the technical quality evaluation of EEG recording. The implementation of the technical quality evaluation of EEG recording is helpful to acquire technically satisfactory EEG records, which may improve the accuracy of results in both the visual and the automatic EEG interpretation, and ease the laborious work of EEG technicians in the recording progress.     

Anionic polymerization of fluorine-containing vinyl monomers, 12. Anionic polymerization mechanism of hexafluoro-1,3-butadiene

Initiation and propagation reaction mechanisms of the anionic polymerization of hexafluoro-1,3-butadiene (HEBD) were investigated. The initiation reaction with caesium tert-butoxide was found to be completed within 5 min although the reactions were carried out at a much lower temperature than that of the polymerization reaction. The initiation reaction was, therefore, inferred to take place in an anionic fashion by adding the tert-butoxide anion to HFBD. In order to clarify the propagation reaction mechanism of HFBD which yielded a polymer with a polyvinylene structure, the polymerization reactivity of HFBD and hexafluoro-2-butyne (HFBY), the isomerization of HFBD to HFBY, and the structural difference between poly(HFBD) and poly(HFBY) were discussed. In spite of the low yield of HFBY by the isomerization reaction under polymerization conditions, higher yields of poly(HFBD) were obtained. Judging from the X-ray analysis which showed that poly(HFBD) was highly crystalline and poly(HFBY) was amorphous, poly(HFBD) might not be produced by polymerization of HFBY. An addition reaction of the propagating anion to the carbon-2 of the HFBD monomer followed by isomerization at the propagating living end to yield poly[1,2-bis(trifluoromethyl)vinylene] is proposed.