Non-invasive dynamic assessment of the elasticity of intracranial structures

The dynamics of the speed of transcranial propagation of ultrasonic impulses has been established in humans. The possibility of detecting the changes in mechanical state of intracranial structures by dynamic measurement of the time of transcranial propagation of ultrasonic impulses (TUPT) has been ascertained for 10 healthy persons and 11 patients with different neurological pathology. The cerebrospinal fluid pressure (CSFP) was simultaneously monitored for 4 of the patients. Spontaneous fluctuations in TUPT and the changes caused by jugular veins, inferior vena cava compression, hyperventilation and temporary retention of breathing were detected for all investigated subjects. Spontaneous TUPT changes in the range of 0.25-0.85 x 10(-4) of initial mean value, which are related with cardiac and respiratory cycles, have been found in healthy persons while in patients they ranged from 0.07 x 10(-4) to 4.5 x 10(-4) of mean time. In healthy persons bilateral jugular vein compression leads to a decrease in TUPT by 1.8-3.0 x 10(-4), while the compression of inferior vena cava gives an increase in TUPT by 1.6-2.6 x 10(-4). Changes in TUPT during these maneuvers in neurological patients were found to be of different amplitude and direction. The rise of CSFP by 8.4-20.2 mmHg (mean 12.4 mmHg) was observed in 4 investigated patients during the compression of jugular veins or during the inferior vena cava compression, while the changes in TUPT obtained during each of such maneuvers were of opposite character. The results suggest that dynamic evaluation of acoustic impedance of intracranial system reflects the changes in the mechanical state of brain parenchyma.     

Surgical relevance of diagnostic imaging techniques in pretherapeutic staging of carcinoma of the esophagus, stomach, colon and rectum

Summary. The increasing spectrum of therapeutic options for tumors of the gastrointestinal tract has resulted in a refinement of the pretherapeutic diagnostic strategies. The diagnostic approach in surgical institutions that are focused on primary surgical resection will therefore be much less sophisticated than in institutions who propose a selective therapeutic approach based on the pretherapeutic tumor stage and prognostic parameters. Pretherapeutic assessment of the depth of tumor infiltration, i. e. the T-category, is essential because most further diagnostic and therapeutic decisions are based on this information. This can today be achieved with a high degree of accuracy by endoscopy and endoscopic ultrasonography. Early T-stages (T1–2) are usually an indication for primary surgical resection and, after exclusion of distant metastases, no further diagnostic studies are required. In patients with locally advanced esophageal, gastric or rectum tumors (T3–4) multimodal therapeutic concepts should be considered. This usually requires additional diagnostic studies. None of the available diagnostic imaging modalities today allows satisfactory pretherapeutic assessment of lymph node metastases. The assumed nodular status should therefore currently not influence therapeutic decisions. Essential is, however, the assessment of distant metastases, since the documentation of distant tumor spread will change the therapeutic approach to a palliative situation. Detailed histologic and molecular-biologic assessment of tumor characteristics is growing in importance. This not only provides therapeutically relevant information regarding tumor grading, but opens the door towards a modern molecular diagnostic approach. It can be expected that in the near future a vast amount of relevant prognostic information can be obtained from endoscopic tumor biopsies, which may soon alter our therapeutic concepts.      

我院抗菌药物用药调查与分析

本文统计了１９９０年和１９９３年抗菌药物购药金额、数量、ＤＤＤ值，计算ＤＤＤ数及每日治疗费用，将总购入量、ＤＤＤ值、ＤＤＤ数及金额数进行排序，求出金额数序号与ＤＤＤ数序号的比值，从中了解全院抗菌药用药频度。本文调查结果认为在本院使用的第三代头孢类抗生素所占金额比重极大，在ＤＤＤ数排序中，居前１０位的头孢类是第一代头孢，喹诺酮类用药频度逐年提高。     

120例门静脉病变的彩色多普勒超声诊部的临床价值

目的:探讨门静脉临床病变类型及超声诊断价值,指导临床治疗及预防。方法:通过120例超声诊断门静脉病变分析总结,对门静脉病变进行归纳分类,指导临床治疗及预防。结果:按门脉节段分类门脉病变分为:①门脉属支病变,②门脉主干病变,③门脉分支病变。每一病变又分门脉血流异常,门脉本身病变,门脉外异常影响门脉。并分析部分异常出现的原因及后果,指导预防及治疗。结论:应用彩超可以评价门脉病变性质、部位,部分指导临床治疗。     

Interocular mismatch in spatial frequency and directionality characteristics of striate cortical neurones

Summary Spatial-frequency dependence of directional tuning and directional bias was compared, for both eyes, in four previously established discrete classes of binocular feline striate cortical neurones. Two classes (respectively direction-selective or bidirectional at optimal spatial frequency) were directionality invariant at all spatial frequencies. In the remaining two classes, both directionbiased at optimal spatial frequency, directional bias either altered or reversed with change in spatial frequency. In all four classes, the directional tuning of a majority of neurones sharpened at high spatial frequency through either eye, although the bandpass characteristics were sometimes dissimilar for the two eyes. All neurones were of the same type through either eye. Amongst the two classes of direction-biased neurones, the strength of bias was commonly different through the two eyes. Where reversal of bias occurred, that reversal took place at different spatial frequencies for each eye. Thus, the direction and orientation preferences of cortical neurones are fixed at optimal spatial frequency, but their envelope of tuning to a gamut of spatial frequencies is not. These differences are potentially related to binocular coding of visual perspective, including dynamic object rotation in visual space.     

Imaging of shifted stimulated echoes and multiple spin echoes

It is shown that a repetitive pulse sequence consisting of two 90° pulses and gradients in a 1:2 ratio around the second 90° pulse generates interscan shifted stimulated echoes (SSTEs) and intrascan multiple spin echoes (MSEs). Separation of these two types of signals is accomplished using specific gradient crusher schemes. The intensity of the SSTEs is an order of magnitude larger than that of the MSEs and determines the signal contrast if both effects are selected simultaneously. The SSTE sequence generates improved contrast between gray and white matter, even at high field, which is explained in terms of increased inverse T₁-weighting for the interscan echo. The MSE image has low signal to noise and no detectable contrast. The effect of interscan diffusion weighting is also discussed.     

Diving physiology and pathophysiology

Summary. Divers have worked at 500 m depth in the sea and have reached 700 m in simulated chamber dives. A prerequisite for this has been extensive physiological studies of the body's reactions to pressure and pressure changes. This paper reviews such physiological and pathophysiological studies with emphasis on recent developments.     

Pharmacokinetics of intravenously administered sodium dichloroacetate in rabbits

ＰｈａｒｍａｃｏｋｉｎｅｔｉｃｓｏｆｉｎｔｒａｖｅｎｏｕｓｌｙａｄｍｉｎｉｓｔｅｒｅｄｓｏｄｉｕｍｄｉｃｈｌｏｒｏａｃｅｔａｔｅｉｎｒａｂｂｉｔｓＧｕＢｉｎ（顾斌）；ＳｏｎｇＬｉｎｇ（宋岭）；ＪｉａｎｇＹｏｎｇｐｅｉ（蒋永培）；ＷｅｎＡｉｄｏｎｇ（文...     

人体中氧氟沙星的立体选择性代谢

５名健康志愿者日服单剂３００ｍｇ氧氟沙星［（±）－Ｏｆ１］后，采用立体选择性的ＲＰ－ＨＰＬＣ手性流动相添加剂法测定尿中Ｓ－（－）－Ｏｆ１和Ｒ－（＋）－Ｏｆ１浓度结果显示Ｏｆ１在人体内呈现立体选择性代谢。尿中排泄的Ｓ－（－）－Ｏｆ１／Ｒ－（＋）－Ｏｆ１之比随时间变化。服药后２ｈＳ／Ｒ是０．８７５，２４ｈ增加到１．１５０．Ｓ－（－）－Ｏｆ１的消除半衰期（ｔ１／２）是４．５７ｈ；消除速率常数（ｋ）是０．１５４ｈ；药时曲线下的面积（ＡＵＣ）为１．１７ｍｇ·ｈ－１．ｍＬ－１；Ｒ－（＋）－Ｏｆ１的ｔ１／２为４．１８ｈ，ｋ为０．１６８ｈ－１，ＡＵＣ是１．７８ｍｇ·ｈ－１·ｍＬ－１；经配对ｔ检验这三对参数间有显著性差异，Ｐ值分别小于０．０１，０．００１和０．００５．因此两对映体在人体内呈现立体选择性处置     

Skin reactions to irritants assessed by non-invasive bioengineering methods

Pathophysiological components of irritant contact dermatitis caused by 3 chemically-different irritants were investigated. 20 healthy volunteers were patch tested with sodium lauryl sulphate, nonanoic acid and hydrochloric acid on the flexor side of the upper arm. The skin response was evaluated after 24, 48 and 96 h by visual scoring and measured by the following bioengineering methods: transepidermal water loss measurement, electrical conductance for measurement of skin hydration, laser Doppler flowmetry for measurement of cutaneous blood flow and 20 MHz ultrasound A-scan for measurement of skin thickness. In spite of homogeneous inflammatory responses, significant differences in the severity of the injury to the skin barrier function caused by the different irritants were found. Also significant differences between irritants were found in the time course of development of maximum irritant reactions. Bioengineering methods indicating inflammatory responses (measurement of blood flow and skin thickness) were helpful in quantifying the irritant response in general, while bioengineering methods indicating epidermal damage (measurement of TEWL and electrical conductance) were helpful in classifying the individual irritants.