Dura arteriovenous malformation of the posterior fossa-clinical and angiographical analysis of 6 cases

Dural arteriovenous malformation of the posterior fossa was infrequently reported in the literatures. We presented 6 cases of dural arteriovenous malformation of the posterior fossa with the presentation of typical examples. Up to the end February, 1974, 119 cases of intracranial arteriovenous malformation were experienced in our clinic, in which there were 6 cases of dural arteriovenous malformation. The ages of our series ranged from 41 to 75 years old and 57 years old in average. Tinnitus and headache were two main symptoms which developed in most of the cases. As for the older symptoms, visual disturbance was seen in 4 cases, unilateral pulsating exophthalmos in 1 case and papilledema in 3 cases. There wers two cases which progressive dementia was developed by the cerebral anoxia due to arteriovenous shung. On examination, a pulsatile bruit was audible at the mastoid region in all cases and a thrill could be palpated along the occipital arteries. Many kinds of durl and/or tentorial arteries which were drained directly into the sinuses at the occipital portion as the feeding arteries were visualized angiographically. Moreover, the angiographical patterns of feeding arteries into the sinuses showed dynamic changes after the operation. As for the treatments, many kinds of surgery were carried out for the cases by the combination method of the next 6 ways. 1. ligation of external carotid artery 2. ablation of periosteum from occipital bone 3. occipital and/or suboccipital craniectomy 4. clipping of almost of all feeding arteries at dura mater and tentorium 5. ligation of threocervical trunk 6. ventriculo-atrial shunt or ventriculo-peritoneal shunt From our experiences, the most effective treatment is thought to be a direct closure of intradural arteriovenous shunt near the sinus at the occipital portion in the early stage.     

10 watt CW, 5000 h lifetime monolithic AlGaAs laser diode arrays

1 cm-wide monolithic laser diode arrays emitting at about 810 nm with a 3 mm total active aperture width have been life-tested at 10 W constant power at 20 degrees C heat-sink temperature. One array has been operated for over 3000 h and has a projected lifetime in excess of 5000 h.<>     

Enhanced ketogenesis in the kidney during hepatic inflow occlusion with the administration of Ringer's acetate solution

BACKGROUND: The blood levels of ketone bodies, which are synthesized principally in the liver, were maintained even during hepatic inflow occlusion if Ringer's acetate solution (AR) was administered, resulting in an improvement of hepatic energy level in the reperfusion phase, as reported in our previous experimental study. The current study was designed to prove that the kidneys are the organs that contribute to synthesize ketone bodies during hepatic inflow occlusion if AR is administered. METHODS: The arterial, central venous, renal venous, and renal tissue ketone body concentrations were determined in rabbits administered AR or Ringer's lactate solution (LR) at 20 minutes of hepatic ischemia and at 30 minutes of reperfusion. The concentrations were also compared in rabbits under AR infusion with or without hepatic ischemia for 20 minutes. Statistical analyses were performed by means of ANOVA: RESULTS: With AR the renal venous ketone body concentration not only was higher than that with LR (p < 0.001) but also was higher than the arterial concentration (p = 0.05). The renal tissue ketone body concentration was higher than in those with LR (p < 0.001) and also than in those without occlusion (p < 0.001). CONCLUSIONS: Ketogenesis is enhanced in the kidney and may compensate for hepatic loss of ketogenic function during hepatic inflow occlusion under AR administration.     

Fluorination of Hydroxyesters with N,N-Diethyl-1,1,2,3,3,3-Hexafluoro Propaneamine

The reactions of N,N-diethyl-1,1,2,3,3,3-hexafluoro propaneamine (PPDA) with Β-hydroxyl esters gave their corresponding fluorides. For example, methyl (S)-(+)-3-fluorobutyrate was obtained from the reaction of methyl (R)-(-)-3-hydroxybutyrate with PPDA. The reaction ofa-hydroxy esters with PPDA gave a mixture of their corresponding fluorides and 2,3,3,3-tetrafluoropropionate esters. However, γ- and δ-hydroxyesters did not give their fluorinated compounds. Hydrolysis of those racemic monofluoroesters with Lipase MY gave optical active monofluorocarboxylic acids and esters. To whom correspondence should be addressed.     

Numerical analysis for eddy current characteristics of magnetically saturated ferromagnetic tubes

Magnetic saturation is applied to ferromagnetic tubes inspected by the encircling or inner coil because suppressing magnetic noise is important for the eddy current testing technique. Eddy current signal characteristics in magnetically saturated tubes are different from those in nonmagnetic tubes. In ferromagnetic tubes, defect signal phase angle is not useful for estimating defect depth because it does not depend on the defect depth. In this paper, numerical eddy current analysis has been done in order to explain the relationship between the defect depth and the phase angle in magnetically saturated tubes. This analysis is performed as follows: 1) The magnetic permeability near the defect is calculated as the non-linear magnetostatic problem. 2) The eddy current distribution is calculated as the linear magnetodynamic problem using the incremental permeability value calculated in step 1. The numerical analysis results reveal that the permeability around the defect remains inhomogeneous and it causes the unique eddy current characteristics. Based on these calculated results, a quantitative evaluation method of determining defect depth is proposed. After determining the defect shape by using signal characteristics obtained from the strongly magnetizing state, the defect depth can be estimated by using the signal amplitude.     

New subtype of apical hypertrophic cardiomyopathy identified with nuclear magnetic resonance imaging as an underlying cause of markedly inverted T waves

OBJECTIVES: The aim of this study was to elucidate the clinical importance of a new subtype of apical hypertrophic cardiomyopathy that could not be diagnosed with the classical diagnostic criteria. BACKGROUND: Apical hypertrophic cardiomyopathy is recognized by a characteristic spade-shaped intraventricular cavity on the end-diastolic left ventriculogram in the right anterior oblique projection, often associated with giant negative T waves [negativity > or = 1.0 mV (10 mm)]. As an underlying cause of giant negative T waves, an additional new subtype of apical hypertrophic cardiomyopathy has been identified. METHODS: In 40 patients with inverted T waves (negativity > or = 0.5 mV), including 26 patients with giant negative T waves, nuclear magnetic resonance (NMR) long-axis images corresponding to the left ventriculogram in the right anterior oblique projection and short-axis images at various levels, including the apical level, were obtained to define the site of hypertrophied myocardium. RESULTS: Long-axis images indicated a spadelike configuration in 17 patients, whereas this diagnostic configuration was not present in the other 23 patients. Nine of these 23 patients had significantly hypertrophied myocardium at the basal level. In the 14 remaining patients, short-axis images indicated no hypertrophy at the basal level and proved that the area of hypertrophied myocardium was confined to a narrow region of the septum or the anterior or lateral wall at the apical level (nonspade apical hypertrophic cardiomyopathy). The hypertrophied myocardium of the nonspade type was so narrowly confined that the mass did not form a spadelike configuration or could not be detected on the long-axis image. CONCLUSIONS: Nonspade apical hypertrophic cardiomyopathy was newly identified on NMR short-axis images, and this could be an additional, important underlying cause of moderately to severely inverted T waves.     

The influence of rush immunotherapy on the production of interleukin-5 from mononuclear cells

Ten children, ranging in age from 2 months to 16 years, were evaluated by bronchograms performed during bronchoscopy. Nine of the ten children had significant pathology demonstrated by the bronchogram that elucidated findings unclear from other imaging procedures at the time of bronchoscopy. Despite the generally negative opinions about the utility of bronchograms in children, information obtained by bronchography can be quite useful. Bronchography during bronchoscopy proved to be quick, simple, and safe.     

Solute partitioning on solidification of nickel-base ternary alloys

The coefficients for equilibrium partition of solute elements between solid and liquid were determined in nickel-base ternary alloys rapidly quenched from a coexisting solid-liquid state. A satisfactory accordance was observed between experimentally and theoretically determined partition coefficients, and factors influencing the ternary partition coefficients were clarified by a thermodynamic procedure. The availability of thermodynamic evaluation of the equilibrium partition coefficient was elucidated for application to nickel-base multicomponent alloys.