The patterns of cell death and of macrophages were investigated in the forebrain and eyes of the tree shrew Tupaia belangeri during five phases of optic cup formation. Seventeen embryos were studied. Three- dimensional reconstructions were made from one embryo of each phase. In phase 1 (V-shaped optic evagination) a midline band of cell death passes through the closing anterior neuroporus. From phases 2 (optic vesicle) to 5 (far-advanced invagination) the midline band of cell death extends in the dorsal wall of the forebrain to its rostral pole and, further, into its ventral wall. At the approximate future position of the optic chiasm this ventral pycnotic area, predicted but so far unidentified by others, is connected to a previously described second band of cell death passing through the optic anlagen. Recently, evidence has been presented that chicken embryos develop holoprosencephaly and cyclopia when ventral forebrain structures are lost secondary to experimentally induced apoptosis. Our findings in Tupaia suggest that, in cases of spontaneous malformations of this kind, such an atypical pycnotic area in the ventral telencephalon might result from the defective regulation of cell death processes during optic cup formation. In the forebrain and eyes of Tupaia, the occurrence of bands of cell death precedes the appearance of the earliest intraepithelial macrophages. From phase 3 (onset of invagination) onwards almost all of them are concentrated along the band of cell death. 相似文献
The dermatologist's procedure was introduced in 1972 by employers' liability insurance funds in the industrial, agricultural and public sectors of Germany's statutory occupational accident insurance as a "procedure for early detection of occupational skin diseases". So far, it is still the most relevant tool for secondary prevention in occupational dermatology in Germany. According to the intention of this procedure, insured persons with a skin disease in which an occupational aetiology is suspected must be offered preventive measures and, if necessary, given appropriate treatment to avoid their losing their jobs. On the initiative of the Central Federation of Industrial Professional Associations (HVBG), a study group was set up in 1999 from among its membership in cooperation with the Working Committee of Occupational and Environmental Dermatology (ABD) and the Professional Organisation of German Dermatologists (BVDD) to improve on the efficiency of the "classic" dermatologist's procedure. The proposed "optimised" dermatologist's procedure is based on the assumption that early detection followed by competent and intensified skin protection and skin care will be successful in retarding or stopping the progression of occupational dermatoses, while later treatment is likely to be less effective. In October 2002, a pilot study started in Northwest Germany to establish by scientific evaluation whether the implementation of secondary protective measures is definitively better when the provisional "optimised" dermatologist's procedure is followed. The study results should allow detailed suggestions for an improved dermatologist's procedure before it is introduced nationwide. 相似文献
In the sick sinus syndrome, in sinu-atrial conduction defects or in atrial flutter or fibrillation a stress-adapted, frequency-adapted stimulation cannot be obtained by the processing of the atrial potential. Here one depends on partly extracardiac parameters which contain informations about the metabolic and stress situation, respectively. A survey of the parameters for a frequency-adapted stimulation discussed at present is given and a critical valuation of them is carried out. It is shown that all parameters up to now experimentally and clinically, respectively, tested are more or less problematic and that the way out of the difficulty most consist in deriving the controlled variable for a stress adapted stimulation rate from several parameters. 相似文献
The exact regional correlation of findings of facial bone scans, planar or SPECT, to dental orthopan X-ray films (OPT) is difficult because of the very different projection techniques. To improve correlative imaging in this regard a projection algorithm was developed that uses SPECT data of the skull for reconstructing an orthopan tomoscintigraphic projection. Fourteen conventional SPECT slices of the upper and lower jaws were obtained during bone scanning. All mandibular slices were superimposed resulting in a horseshoe shaped structure, which was marked by an ROI which was divided into segments. All 14 SPECT slices were then masked by this segmental ROI, thereby marking the teeth-carrying bone in all slices. The information from this horseshoe like ROI is then transformed into lines. Line by line arrangement results in an orthopan projection, the orthopan tomoscintigram. This new display allows 1:1 true scale superimposition with the X-ray OPT and markedly facilitates correlative imaging. 相似文献
The double contrast enema is the most effective morphological screening method for the evaluation of the whole small bowel. Its sensitivity is 85%, its specifity 96.7%. In specific clinical problems the number of pathological roentgen findings rises: from 34.4% when all indications are taken into consideration to 58% in indications specific to the small intestine such as Morbus Crohn or the malabsorption syndrome. Search for tumours and the double contrast of the small bowel in unclear gastro-intestinal bleeding are unproductive. The weak point of this screening method is the lower part of the small intestine. Therefore, the selective peroral or retrograde analysis of the terminal ileum supplement the contrast method. A precondition for good results is an adequate technical standard. Besides the clinical results some technical results are therefore discussed such as contrast medium quantities, examination and X-ray time, radiation exposure and influences on the image quality. 相似文献
Background: Pain on injection of propofol in children has been reported to be as high as 30-80%. The reason for the pain is assumed to be the aqueous phase of the propofol emulsion. Therefore, for the first time, this study tested the hypothesis that dilution of propofol to a 0.5% emulsion might reduce the incidence of pain during propofol injection.
Methods: The study design was prospective, monocenter, double-blind, and randomized. Sixty-four children aged 2-6 yr were scheduled to receive 0.5% or 1.0% propofol in a medium-chain-triglyceride/long-chain-triglyceride emulsion. Incidence and intensity of pain were assessed by spontaneous expressions of pain and withdrawal of the arm. In a subgroup of 21 children, serum triglyceride levels were measured before and 3 and 20 min after induction. Adverse events were recorded.
Results: Amounts of propofol required until loss of eyelash reflex were 4.40 +/- 1.01 mg/kg for 0.5% propofol and 4.31 +/- 0.86 mg/kg for 1.0% propofol. Percentages of children who showed at least one pain reaction were 23.3% in the 0.5% propofol group and 70.0% in the 1.0% propofol group (P < 0.001). Serum triglycerides were higher in the 0.5% propofol group 3 and 20 min after injection (251.7 vs. 148.8 mg/dl; P = 0.001 and 135.5 vs. 75.5 mg/dl; P = 0.03). Adverse events or complications did not occur. 相似文献