Interleukin-12/T cell stimulating factor,a cytokine with multiple effects on T helper type 1 (Th1) but not on Th2 cells

At least two subsets of CD4⁺ T helper cell lymphocytes termed T_h1 and T _h, 2 exist in the mouse and probably in humans. They are characterized by the secretion of different lymphokines and by their functional behavior. Dysregulated expansion of one or the other subset may be one reason for the development of certain diseases. Thus, it is of importance to define the signals involved in the differentiation and activation of the two T_h cell subsets. It is known and has been confirmed in this report that the cytokine interleukin (IL)-1 acts onT_h2 cells but not on T_h1 cells. We now report that a previously identified cytokine which was provisionally termed T cell stimulating factor is identical with IL-12 and exhibits a reciprocal behaviour to IL-1. IL-12 has several effects on T_h1 cells. It can induce the proliferation of certain T_h1 cells in combination with IL-2. Synthesis of interferon (IFN)-γ by T_h1 cells can be triggered by IL-2 plus IL-12. In contrast to the IFN-γ production observed after T cell receptor (TcR) CD3 stimulation of T_h1 cells with lectin Concanavalin A the IFN-γ production induced by IL-12+IL-2 is insensitive to the immunosuppressive drug cyclosporin A. Furthermore, IL-12 enhances the TcR/CD3-induced synthesis of IFN-γ of several T_h1 clones. Finally, IL-12 (+ IL-2) induces homotypic cell aggregation of T_h1 clones. This type of cell aggregation depends on the participation of LFA-1 and ICAM-1 molecules. In all activation systems with T_h1 cells no effect of IL-1 was demonstrable. In contrast, only IL-1 but not IL-12 served as a co-stimulatory signal for several T_h2 cell lines activated via the TcR/CD3 complex.     

计算机图象处理研究圆窗区及其临床意义

在手术显微镜下观察了122个成人的圆窗,43.4％未见龛膜存在,属开放型;56.6％有龛膜,并可分为封闭型、穿孔型和网状型三种。使用计算机图象分析系统处理70个颞骨的切片图象并进行测量。讨论了圆窗区域手术中的有关要点。     

ECLIPS: An extended clinical laboratory information processing system

The clinical laboratory is regarded as a component of the medical care system extending from physician to laboratory staff and back to physician. From this concept a computer-based system of laboratory information is derived, emphasizing: (1) total laboratory responsibility for the test and its request, and (2) physician-oriented output reports.     

A Negative Slow Wave Related to Conceptual Load Which Vanishes if the Amount of Load is Increased? A Reply to Ruchkin and Johnson

Ruchkin and Johnson (1991) claim that the mode of responding used by Rösler & Heil (1991) may have camouflaged effects of a negative slow wave that Ruckin et al. (1988) had found to be related to the difficulty of mental calculation problems. This criticism is addressed by three arguments which support the interpretation of Rösler and Heil (1991). According to this view, the negative slow wave in question is more likely related to unspecific processing factors, such as effort and event expectation, than to specific processing demands such as these induced by mental arithmetic.     

The sources of odors from stressed rats

Recent studies [8,9] have shown that odors from stressed Norway rats act as signals to which other rats respond primarily by overall changes in activity and exploration. At present the source of these odors is unknown. In this study odors from urine, feces and the bodies of stressed rats were delivered along a runway in which the subjects had been previously trained to run for a water reward in the presence of odors from non-stressed rats. The results indicate that odors are released from the body surface and in the urine but not the feces of stressed rats.     

Preprocessor Adapts Cardiovascular Signals to a Minicomputer

A laboratory-developed analog signal processor, driven by a conventional polygraph recorder and associated signal conditioning devices, provides automatic heart beat-by-heart beat preprocessing of various cardiovascular functions for input to a laboratory-type minicomputer. The technique of preprocessing individual functions, integrated with the minicomputer system which includes an A/D converter and teletype as input-output peripherals, provides a low-cost data acquisition and reduction system for the on-line computation and analysis of cardiovascular functions in experimental research applications. Such preprocessing more efficiently uses the minicomputer's memory to handle large amounts of information since the digitized data is in the form of one data sample, per function, per heart beat. Preprocessing analog data provides a low density data format and simplified software programs that are ideally suited for the utilization of a minicomputer in this on-line application.     

Firing of inferior colliculus neurons in response to low-frequency sound stimulation during sleep and waking

SUMMARY  In vivo extracellular recordings of 102 units in the central nucleus of the inferior colliculus (IC), were made in chronically implanted guinea-pigs during the sleep/wake cycle. During wakefulness, the units were classified according to their response characteristics. Most neurons (63%) recorded showed changes, increasing or decreasing in the number of evoked discharges during the animal's transitions between wakefulness and slow-wave sleep. In the paradoxical sleep phase, the result was similar; changes were observed in most neurons, while only 11% of units did not shift their discharge pattern during ipsilateral sound stimulation.
The post-stimulus time histogram of the overall evoked pattern of discharge showed sleep/wake dependency, i.e. changed in 35% of the units recorded during the 50 ms of sound stimulation.
Fifty-five percent of auditory neurons did not show any change in the spontaneous firing rate during slow-wave sleep as compared to the previous waking period, while 22% exhibited a discharge increase and 23% decreased their firing. During paradoxical sleep, 14 out of 17 cells increased their spontaneous firing rate. The IC auditory neurons send descending connections to regions such as the dorsal pontine nuclei, known to mediate sleep processes. Thus, for constant auditory input, the firing rate or number of discharge variations are due to functional shifts in the sleeping brain. Auditory processing is present during sleep and differs from that observed during wakefulness. Differences were observed in the evoked firing number and/or spontaneous rate, as well as in the pattern of discharge. The ultimate reason for auditory unit shifts during sleep remains yet unexplained.     

Fast Adaptive Unsharp Masking with Programmable Mediaprocessors

Unsharp masking is a widely used image-enhancement method in medical imaging. Hardware-based solutions can be developed to support high computational demand for unsharp masking, but they suffer from limited flexibility. Software solutions can easily incorporate new features and modify key parameters, such as filtering kernel size, but they have not been able to meet the fast computing requirement. Modern programmable mediaprocessors can meet both fast computing and flexibility requirements, which will benefit medical image computing. In this article, we present fast adaptive unsharp masking on two leading mediaprocessors or high-end digital signal processors, Hitachi/Equator Technologies MAP-CA and Texas Instruments TMS320C64x. For a 2k × 2k 16-bit image, our adaptive unsharp masking with a 201 × 201 boxcar kernel takes 225 ms on a 300-MHz MAP-CA and 74 ms on a 600-MHz TMS320C64x. This fast unsharp masking enables technologists and/or physicians to adjust parameters interactively for optimal quality assurance and image viewing.