Radiology of postnatal skeletal development

Composites of C1 and C2 were analyzed in various roentgenographic projections to elucidate osseous interrelationships and the effect of overlap of different portions of these two vertebrae in standard radiographic projections during differing stages of postnatal chondro-osseous transformation. In anteroposterior projections the dentocentral synchrondrosis of C2 normally was located below the inferior rim of the C1 anterior ossification center. The upper extent of the dens ossification center was behind this anterior C1 center. The overlap made visualization of the ossiculum terminale difficult. The spinous process of C1 could be confused with the ossiculum. In tranverse projections, the normal laxity characteristic of young children allowed considerable variation in rotational interrelationships. Various degrees of such instability are illustrated. In lateral views variation of the anterior contour of the dens was significant. Such variation must be considered developmental due to the location and direction of growth of the chondrum terminale and interactive modeling between C1 and C2 to allow extension at this particular joint.     

肌肉动力与断端显微位移的动态观察

目的：观察骨折愈合过程中不同时期肌力和位移的变化，探讨肌肉动力在骨折愈合中的作用。方法：采用肌力和位移传感器，测试夹板固定下兔胫骨干闭合骨折后的肌力与位移变化，计算机同步数据采集。结果：正常肌力5．04kg，伤后第一天肌力1．87kg，位移0．87mm；7天对肌力3．35kg，位移最大为1．02mm；14天对肌力接近正常5．01kg（P＞0．05）；21天对肌力恢复正常，位移下降至0．28mm；35天时位移仅为0．035mm，骨折愈合。结论：肌肉动力为骨折端提供间歇性生理应力为骨折愈合所必需，骨折愈合的最佳应力是该部生理状态下所承受的肌力。在功能活动时允许断端一定范围的纵向活动，能促进骨折愈合。     

双端固定桥基牙位移的激光全息干涉计量研究

本文采用激光全息干涉计量术在动物模型上测量了双端固定桥基牙受力后的位移情况，分析了修复前，后基牙位移变化的规律，指出激光全息干涉计量术是一种精确而且先进的实验方法。     

Optical method for determining the frequency response of pressure-measurement systems in respiratory mechanics

An optical method for measuring the frequency response of pressure transducers is described. The method allows the calculation of the varying pressure of ate pressure. Displacement is measured by a photodetector position sensor with the aid of a laser beam reflected on a mirror attached to the loudspeaker diaphragm. The method is based on the short time response of the optical system and it presents some advantages with regard to the usual dynamic calibration using a microphone reference: (a) it has a good response at low frequencies; (b) it is unaffected by environmental conditions; and (c) the system can easily be recalibrated.     

The course of the anterior choroidal artery

Summary Landmarks of the course of the anterior choroidal artery and of the basal vein are described with reference to displacements by supratentorial masses.     

双侧游离端义齿不同固位装置对基牙位移的实验研究

目的：探讨双侧游离端可摘局部义齿的不同因值装置对基牙的影响。方法：分别以联合卡环、延长卡环和套筒冠作为固位装置，制作双侧游离端义齿，在一侧上下习：列间放置食片，当咬合时用高精密度激光位移测量仪测得双侧基牙的位移量，并加以统计分析。结果：3种不同固位体的游离端义齿，在垂直负荷时，双侧基牙54┰45都有不同程度的水平及垂直向移位、扭转及倾斜。套筒冠的垂直向位移量最大，水平扭转位移量最小，且远缺隙侧基牙了4┰4的水平位移量大于近缺隙侧蛀牙了5┰5。结论：各种因值体的基牙动度与固位体和基牙间的连接刚性相一致。刚性度越好，基牙动度越小。套筒冠可使胎力沿基牙牙体长轴传递，降低基牙所受扭转力，多个基牙共同承力，可减轻末端基牙的负胆。     

Effects of penicillins on binding of phenytoin to plasma proteins in vitro and in vivo

Effects of penicillins on the binding of phenytoin to plasma proteins were examined in vitro and in vivo. The results from in vitro studies showed that the penicillins including oxacillin and dicloxacillin were effective in displacing phenytoin from its binding sites. In vivo, the total phenytoin concentration in serum decreased during penicillin administration, while the free phenytoin concentration increased. As a result, penicillins caused a significant increase in the apparent volume of distribution and in the total body clearance of phenytoin. These results can be explained on the basis of the displacement of phenytoin from its plasma protein binding site by penicillins.     

The effect of displacement from protein binding on serum and tissue fluid levels of cephazolin

Displacement of cephazolin, a highly protein-bound β-lactam antibiotic, by sulpha-phenazole was studied in vitro and in vivo. In vitro, the sulphonamide was effective in displacing the antibiotic from its binding sites at the concentration 100–1000 μmol I^?1. In vivo, both the serum and the tissue fluid concentration of free cephazolin increased significantly in rats concomitantly treated with sulphaphenazole.     

Antagonism of morphine by long acting narcotic antagonists

Thirty-six female albino rats, trained to run for a chocolate reward in a circular runway, were treated according to 6×6 Latin square schemes with five doses of 3-quinuclidinylbenzilate, ranging from 0.1 to 10 mg/kg, or the vehicle. On experimental days there were 6 consecutive trials. Intraperitoneal injections were administered 20 min before the first trial. The apparatus was automated as far as the opening of sliding doors and the recording of the duration of running, subdivided into latency and running-time, were concerned. Along with the duration of running, the behaviour shown in the various parts of the maze was analysed. The drug caused a marked, dose-dependent increase of the latency, whereas the effect on running-time was comparatively small. During the latency the frequency of ambivalent behaviours, shown at the transition of the start-goal compartment and the runway, increased under the influence of 1 mg/kg or more. Concomitant increases were noted in the frequency of displacement activities, which were absent in control animals. The results were interpreted as a drug-induced intensification of a conflict, existing in normal animals between the tendency to stay in the vicinity of the reward and the tendency to run for a subsequent reward.