Bibliothek

Notizen: A method to enhance the reflectivity of acoustic phase conjugate mirrors by nonlinear piezoelectricity is discussed. Static electric or static stress fields were applied together with the pump electric field. In highly nonlinear piezoelectric ceramics, the phase conjugate reflectivity was enhanced by the factor of 50 using this method. The maximum reflectivity reached 10−2. © 1996 American Institute of Physics.

Notizen: The valence level hole spectral functions of linear C2n+1 (n=1–6) clusters are calculated by the ab initio third order algebraic diagrammatic construction [ADC(3)] Green function method and the outer-valence Green function (OVGF) method using an extended basis set. The vertical electron affinities of linear C2n+1 (n=1–6) clusters are also evaluated by the same methods. With an increase of the number of carbon atoms, the KT energy levels become more closely spaced and start to form quasi-continua. The original spectral strength of the main line becomes distributed over several lines of comparable intensity. With an increase of the number of carbon atoms, the one-electron (or even quasi-particle) picture of the ionization breaks down because of the interaction between the initial single hole level and the final two-hole-one-particle levels. The spectral intensity of the first four ionization levels remains fairly constant independent of the number of carbon atoms. The agreement of the affinities of C2n+1 (n=1–6) with experiment is in general very good. Two anionic states are found to be bound for C9, C11 and C13. © 1997 American Institute of Physics.

Notizen: Summary The effects of low and high NaCl diets on plasma glucose and insulin responses to glucose ingestion were investigated in 15 patients with essential hypertension. Oral glucose (75 g) tolerance tests were carried out while patients were taking diets with low (2 g/day) and high (20 g/day) NaCl content. Fasting plasma glucose and insulin levels were both significantly lower during ingestion of the high NaCl diet (p〈0.05). After glucose ingestion, the incremental areas under the two hour plasma glucose and insulin curves were significantly smaller during ingestion of the high NaCl diet (glucosep〈0.005 and insulinp〈0.025). These findings that low NaCl diets increase the glycemic response to glucose loads suggest that use of NaCl restriction for the treatment of essential hypertension may not always be desirable.

Notizen: Abstract Manual reduction with the index finger (modified Hutchinson's maneuver) enabling simple and safe manual reduction of infantile intussusception is described. The procedure was used in four patients, two boys and two girls, ranging in age from 2 to 15 months, as greater than normal compression was necessary and/or serosal splitting occurred during conventional reduction. The technique is as follows: in addition to the proximal bowel compression with Hutchinson's maneuver, the surgeon inserts his index finger into the intussusceptum via its neck. The finger enables the surgeon to sound a wider space between the intussusceptum and intussuscipiens, which is most likely to be responsive to bowel compression. Although the intussusceptions in the four patients were categorized as ileo-ileo-colic (three cases) and ileo-ileal (one case) types, this manual reduction technique was successful in all cases, no bowel rupture occurred, and hospitalization was no longer than with the conventional procedure. We conclude that this modified Hutchinson's maneuver may contribute to successful surgical reduction of infantile intussusception.

Notizen: Summary 1. Experiments were performed in cats anesthetized with nitrous oxide to study the effects of INC lesions on responses of vestibular nuclear neurons during sinusoidal rotations of the head in the vertical (pitch) plane. Responses of neurons in the INC region were recorded during pitch rotations at 0.15 Hz. A great majority of these neurons did not respond to static pitch tilts, and they seemed to respond either to anterior or to posterior semicircular canal inputs with a peak phase lag of 140 deg (re head acceleration). 2. Responses of vestibular nuclei neurons in intact cats were recorded during pitch rotations at the same frequency (0.15 Hz). Neurons that seemed to respond to vertical semicircular canal inputs showed peak phase lags of 90 deg relative to head acceleration, whereas neurons that responded to static pitch tilts showed peak phase shifts near 0 deg. These results indicate that responses of neurons in the INC region lag those of vestibular neurons by about 50 deg, suggesting that the former neurons possess a phase-lagging (i.e. integrated) vestibular signal. 3. Responses of vestibular neurons in cats that had received electrolytic lesions of bilateral INCs 1–2 weeks previously were recorded during pitch rotations at the same frequency (0.15 Hz). Neurons that presumably responded to vertical semicircular canal inputs showed a peak phase lag of 60 deg relative to head acceleration, a significant decrease of the phase lag compared to normal, whereas responses near 0 deg were unchanged. Gain values of individual cells also significantly dropped from 2.07 ± 0.67 spikes · s−1/deg · s−22 (mean ± SD; normal cats) to 1.27 ± 0.68 spikes · s−2/deg · s−2 (INC lesioned cats) at 0.15 Hz. When responses of vestibular neurons were studied during pitch rotations in the range of 0.044–0.49 Hz in these cats, a large decrease of the phase lag was observed at lower frequencies, whereas the slopes of phase lag curves of vestibular neurons in intact cats were rather flat. 4. Procaine infusion into the bilateral INCs not only resulted in a decrease of 20–50 deg in the phase lag in responses of vestibular neurons that had lagged head acceleration by 90–140 deg before procaine infusion, but also dropped the gain of the response to rotation by an average of 31%, whereas responses of neurons that had showed phase shifts near 0 deg were not influenced consistently. Simultaneous recording of the vestibular neurons and the vertical vestibuloocular reflex (VOR) indicated that the phase advance and gain drop of vestibular neurons occurred earlier than those of the VOR. These results exclude the possibility that the change in dynamic response of vestibular neurons after procaine infusion is due to depression of general brain stem activity that may lead to the phase advance of the VOR, and suggest that the decrease of the phase lag and gain drop in responses of the vestibular neurons was caused by removal of the phase-lagging, feedback signal coming from the INC to the vestibular nuclei.

Notizen: Summary Magnetic resonance (MR) images of nine patients with intracranial vertebral artery occlusion (five proved, four presumed) have been reviewed. In two of nine, both vertebral arteries were occluded and in five of the nine, the basilar artery was also blocked. All occluded arteries showed absence of flow void and were clearly demonstrated as mildly hypo-∼mildly hyperintense structures to brainstem parenchyma on the T1-weighted images. In two of five patients with basilar artery occlusion, retrograde filling of the distal basilar artery was detected. Thus, MR imaging, in particular the T1-weighted image, is a pertinent diagnostic modality for evaluating intracranial vertebral artery occlusion. Angiography does not seem to be required for confirmation.

Notizen: Abstract. This paper presents a practical new lens design for acoustic microscopy. The new lens provides a factor-of-2 higher resolution than currently available commercial lenses for acoustic microscopy, and a reduction in the influence of surface roughness on the image formation. Analysis, computer simulations, and demonstration examples provide convincing evidence that new lens design works efficiently. Whereas most current lens designs emphasize the use of longitudinal waves, the designs presented here focus on the use of transverse or shear waves. In the present study, two kinds of lens designs have been developed: One is a ``center-sealed'' acoustic lens used at the center frequency of 400 MHz and 1 GHz for use with acoustic tone bursts, and the other is a ``high-NA acoustic lens'' used in the center frequency of 30 MHz for use with short pulses. The center-sealed acoustic lens has its center area aperture sealed to prevent longitudinal waves from traveling into the sample so that the acoustic image is substantially composed of shear wave components. The ``high-NA'' acoustic lens has an aperture with a large aperture angle for exciting shear waves in the object. In this study, the mechanisms of image formation with both of these lenses are described and their features are evaluated.

Notizen: Abstract A neonatal case of apo C-II deficiency with hypertriglyceridaemia and xanthomas is presented. The patient responded well to a special diet formula containing medium-chain triglycerides (MCT). This is the first case of apo C-II deficiency to be discovered during the neonatal period.

Notizen: Abstract Objectives: Omeprazole is metabolized mainly by CYP2C19 which has two major mutations (CYP2C19*2 in exon5 and CYP2C19*3 in exon4) associated with the poor metabolizer (PM) phenotype. The aim of this study was to examine the relationship between genetic polymorphism of CYP2C19 and metabolism of omeprazole administrated as a single dose or as repeated-doses, which were in both cases co-administered with clarithromycin. Methods: Twelve healthy Japanese subjects were typed for CYP2C19 polymorphism. In the single-dose study, plasma levels of omeprazole and its metabolites were measured for 24 h after administration of 20 mg omeprazole and 400 mg clarithromycin to six healthy Japanese subjects. In the repeated-dose study, plasma levels of omeprazole and its metabolites were measured after repeated oral administration of 20 mg omeprazole and 400 mg clarithromycin twice daily for 6 days and then after 20 mg omeprazole and 400 mg clarithromycin once on the 7th day to the other 6 healthy Japanese subjects. Results: In the single-dose study, the areas under the plasma concentration-versus-time curve (AUCs) of omeprazole of homozygotes for the wild-type allele (*1/*1 n = 2), heterozygotes (n = 3) for the CYP2C19*2 (*1/*2) or for the CYP2C19*3 (*1/*3) and heterozygote (n = 1) for the two defects (*2/*3) were on average 450, 1007 and 6710 ng · h−1 · ml−1, respectively. The ratios of AUCs of omeprazole/5-hydroxyomeprazole for *1/*1, *1/*2 or *1/*3 and *2/*3 were 1, 2 and 30, respectively. In the repeated-dose study, the AUCs of omeprazole for *1/*1, *1/*2 or *1/*3 and *2/*3 were 4041 (n = 2), 3149 (n = 3) and 6684 (n = 1) ng · h−1 · ml−1, respectively. The ratios of AUCs of omeprazole/5-hydroxyomeprazole for *1/*1, *1/*2 or *1/*3 and *2/*3 were 7, 11 and 30, respectively. In the repeated-dose study, the AUC of omeprazole of *1/*1 genotypes was nine-fold higher, that of *1/*2 and *1/*3 genotypes was three-fold higher, and the Cmax value of omeprazole was three-fold higher compared with subjects with the same genotype in the single-dose study. However, there were few differences in the AUC and Cmax of omeprazole between the *2/*3 genotype in the single-dose study and the homozygote for the CYP2C19*2 (*2/*2) in the repeated-dose study. Conclusion: Subjects with *1/*1, *1/*2 and *1/*3 genotypes in the repeated-dose study had lower CYP2C19 activity than subjects of the same genotype in the single-dose study. The difference in omeprazole metabolism between subjects with different genotypes observed on day 1 seemed to disappear after 7 days of repeated-dose administration.

Notizen: Abstract   Twenty-three knees of 21 patients over 40 years of age with discoid lateral menisci were examined by radiography.The mean age of the patients was 59.7 years (range: 40–78 years). No patient had symptoms before the age of 40 and only 12 knees gave symptoms from the lateral compartment, although tears of a discoid lateral meniscus were diagnosed by arthrography in 21 of the 23 knees. Varus inclination occurred more frequently than valgus inclination. Subchondral bone sclerosis was more common in the medial compartment. However, high incidences of marginal osteophytes in the lateral compartment and morphological anomalies (cupping or flattening) of the lateral tibial plateau were revealed by radiography.