AMP deaminase activity of skeletal muscle in neuromuscular disorders in childhood. Histochemical and biochemical studies

We studied the histochemical staining and biochemical activity of AMP deaminase in biopsied muscle in Becker-type muscular dystrophy (BMD), Fukuyama-type congenital muscular dystrophy (FCMD), Duchenne-type muscular dystrophy (DMD), Werdnig-Hoffmann disease (WH) in order to elucidate the change of AMP deaminase activity in muscle with neuromuscular disorders in childhood. The intensity of AMP deaminase staining did not decrease in BMD with mild pathologic change, but in DMD, FCMD and WH it decreased in parallel with the severity of the pathologic change. The biochemical activity of AMP deaminase did not decrease in muscle with mild pathologic change in patients with DMD and tended to decrease according to the progress of the disease. The activity of AMP deaminase in muscle of patients with FCMD and WH which showed severe pathologic change was remarkably low. It was demonstrated that the decrease in the activity of AMP deaminase was related to the intensity of pathologic change rather than diagnosis of a neuromuscular disorder.     

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)     

Polymers containing stable free radicals, 6. Reactions of 2,4,6-triphenyl-3,4-dihydro-s-tetrazin-1 (2H)-yl (1,3,5-triphenylverdazyl) with organometallic compounds

2,4,6-Triphenyl-3,4-dihydro-s-tetrazin-1(2H)-yl ( 1 ) (1,3,5-triphenylverdazyl) was allowed to react with ethyl- and butyllithium, ethyl-, isopropyl-, and butylmagnesium bromide, as well as benzylmagnesium chloride to give the coupling products 2a–d . These results indicate that structures corresponding to 2 are present in the polymers resulting from vinyl monomers containing the verdazyl structure, if they are initiated with alkyllithium or a Grignard reagent. A reaction mechanism is discussed.     

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.