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1.
M Engelhardt P Bast N Jeblink W Lauer A Popovic H Eufinger M Scholz A Christmann A Harders K Radermacher K Schmieder 《Minimally invasive neurosurgery》2006,49(2):98-103
This study was performed to evaluate the surgical strategy in patients with calvarial tumours, in order to design and modify a robot-assisted trepanation system. A total of 75 patients underwent craniectomy for the treatment of calvarial tumours during the 10-year period from 1993 to 2002. The patients' complaints, the size, location and histology of the tumour, and the various cranioplasty techniques used were analysed retrospectively. In a second procedure several craniectomies at typical locations according to the study's results were performed in a laboratory setting using a hexapod robotic tool, constructed at the Helmholtz-Institute, RWTH Aachen University, and plastic model heads. The workflow was documented and the reproducibility and the accuracy of the procedure were registered. A total of 83 surgical procedures were performed on 75 patients. The majority (87 %) of lesions treated surgically were located in the frontal, temporal and anterior parts of the parietal region. Histological examination revealed benign lesions in 66 % of the patients and dural involvement in 46 %. According to these results craniectomies were performed using the robotic system. Mean positioning accuracy of the robotic system while milling was 0.24 mm, with a standard deviation of 0.04 mm, and maximum error under 1 mm. Craniectomies leaving a 1-mm layer of the tabula interna intact to ensure a healthy dura were performed in several regions successfully. The majority of calvarial tumours, requiring surgical treatment in our patients, were located in cosmetically relevant areas in which drilling can be carried out with the robotic trepanation system. Consequently, the surgical approach had to be planned carefully in order to achieve a good cosmetic outcome. 相似文献
2.
Kerstin Schmidt Johannes Hoffend Annette Altmann Ludwig G Strauss Antonia Dimitrakopoulou-Strauss Britta Engelhardt Dirk Koczan J?rg Peter Thomas J Dengler Walter Mier Michael Eisenhut Uwe Haberkorn Ralf Kinscherf 《Journal of nuclear medicine》2006,47(3):543-551
Growth of malignant tumors is dependent on sufficient blood supply. Thus, inhibition of tumor angiogenesis is emerging as a promising target in the treatment of malignancies. Human angiostatin (hANG) is one of the most potent inhibitors of endothelial cell proliferation, angiogenesis, and tumor growth in vivo. However, its mechanisms operating in vivo are not well understood. METHODS: To obtain more information about functional changes in the angiogenic process, we established Morris hepatoma (MH3924A) cell lines expressing hANG (hANG-MH3924A). The effects of hANG expression on proliferation and apoptosis of human umbilical vein endothelial cells (HUVECs) were measured in coculture experiments in vitro. To evaluate changes in tumor perfusion and blood volume, H2 15O and 68Ga-DOTA-albumin (DOTA is 1,4,7,10-tetraazacyclododecane-N,N',N',N'-tetraacetic acid) were used for PET studies in vivo. Additionally, immunohistologic quantification of vascularization, apoptosis, and proliferation as well as gene array analyses were performed. RESULTS: Our in vitro experiments demonstrate reduced proliferation and increased apoptosis in HUVECs when being cocultured with hANG-MH3924A. In support, tumor growth of hANG-MH3924A is diminished by 95% in vivo. However, tumor perfusion and blood volume are increased in hANG-MH3924A corresponding to an increased microvessel density. Furthermore, hANG-transfected tumors show changes in expression of genes related to apoptosis, stress, signal transduction, and metabolism. CONCLUSION: hANG expression leads to inhibition of tumor growth, increased apoptosis, and changes in the expression of multiple genes involved in stress reactions, signal transduction, and apoptosis, which indicates a multifactorial reaction of tumors. An enhanced microvessel density is seen as part of these reactions and is associated with increased perfusion as measured by PET. 相似文献
3.
The discovery of an inducible isoform of cyclooxygenase (COX-2) requires a refinement of the theory that inhibition of cyclooxygenase
activity is responsible for both therapeutic and side-effects of nonsteroidal anti-inflammatory drugs (NSAIDs). Pharmacological
results with developmental compounds suggest that COX-2 is the relevant target for the therapeutic (i.e. anti-inflammatory)
effects of NSAIDs, whereas gastric and renal side-effects are related to inhibition of constitutive COX-1. However a role
of COX-1 in inflammation cannot be excluded. Furthermore, more research effort is needed to investigate the functional relevance
of COX-2 in normal tissue. 相似文献
4.
HJ Aubin S Tilikete C Laureaux HT Nguyen Hac MC Roullet-Volmi S Troupel D Barrucand 《European psychiatry》1995,10(8)
The aim of this study was to assess alcoholic inpatients' smoking and coffee intake variation following withdrawal. Only moderate smokers (less than 30 cigarettes/day) showed a significant increase of cigarette consumption after alcohol withdrawal. However, their urinary cotinine level did not vary, suggesting a behavioral, and not biological, compensation through smoking following alcohol withdrawal. Heavy smokers (30 cigarettes/day or more) showed no significant clinical or biological variation of smoking behavior. Coffee consumption increased after alcohol withdrawal in all patients, irrespective of smoking habits. 相似文献
5.
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7.
Sukal Sean A. MD PhD † Tudisco Marie HT † Strippoli Barbara HT † Nehal Kishwer S. MD † 《Dermatologic surgery》2005,31(7):763-766
Background Processing multiple tissue sections in large Mohs cases is time consuming and labor intensive.
Objective To present innovative laboratory techniques to facilitate processing of large Mohs cases.
Methods A method for processing a large dermatofibrosarcoma protuberans Mohs case is outlined.
Results Modifications in tissue processing and equipment employed in a large Mohs case are presented.
Conclusion Innovative modifications to the standard Mohs laboratory technique can facilitate processing of large Mohs cases, resulting in high-quality, rapid frozen sections while optimizing efficiency. 相似文献
Objective To present innovative laboratory techniques to facilitate processing of large Mohs cases.
Methods A method for processing a large dermatofibrosarcoma protuberans Mohs case is outlined.
Results Modifications in tissue processing and equipment employed in a large Mohs case are presented.
Conclusion Innovative modifications to the standard Mohs laboratory technique can facilitate processing of large Mohs cases, resulting in high-quality, rapid frozen sections while optimizing efficiency. 相似文献
8.
Huberta Engelhardt Berend Feddersen Kai Boetzel Soheyl Noachtar 《Clinical neurophysiology》2007,118(10):2282-2286
OBJECTIVE: Caloric stimulation leads to a reduction of the cerebral blood flow in the visual cortex. This reduction has been attributed to the suppression of visual input caused by nystagmus induced by caloric stimulation. We investigated the influence of caloric stimulation on transient flash and steady-state flash visual evoked potentials. METHODS: Visual evoked potentials to 1 and 10 Hz flash stimulation were recorded in 12 normal subjects at baseline, during nystagmus induced by caloric stimulation with cold water, and after the cessation of nystagmus. RESULTS: Neither the amplitude of the transient flash visual evoked potentials (1 Hz stimulation) nor the amplitude of the steady-state flash visual evoked potentials (10 Hz stimulation) was influenced by caloric stimulation compared to baseline. CONCLUSIONS: The deactivation of the visual cortex by caloric stimulation does not seem to affect transient flash or steady-state flash visual evoked potentials. Reduction of cerebral blood flow in the visual cortex does not affect the processing of visual qualities (e.g., luminance and pattern). SIGNIFICANCE: Caloric stimulation does not reduce the amplitudes of transient flash or steady-state flash visual evoked potentials. 相似文献
9.
The aim of present study was to characterize the topographical effect of thiopental on the EEG during induction of anesthesia. A multichannel (19 channels) digital EEG was recorded in 10 patients undergoing surgical treatment. The period during induction of anaesthesia before intubation was investigated in regard to peak frequency, amplitude, topography, and amplitude in conventional frequency bands. The main findings were a slowing of the EEG with a simultaneous increase of amplitude in the predominant EEG frequency (peak frequency) during induction. The topographical analysis showed a clear change of localization of the peak frequency in the occipito-frontal direction. Berger described the effect of thiopental on electrical cortical activity as early as 1933. Since then, many studies have investigated its influence on the EEG, but few have tried to characterize the effects of topographical changes in a quantitative way. 相似文献
10.
E L Engelhardt M Sankar C Y Wu-Wang M R Thomas W R Walker J Neu 《Journal of pediatric gastroenterology and nutrition》1991,12(4):494-500
Using the neonatal piglet, the effects of dietary cholesterol deprivation on growth, intestinal enzyme activity, intestinal and hepatic 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoA reductase), and serum lipid were studied. Six litters of piglets were randomly assigned to one of two feeding regimens: restricted (800 ml of formula/24 h) versus unrestricted (1,200 ml of formula/24 h). Within litters, piglets were separated by sex, then randomly assigned to a formula containing low cholesterol (less than 2 mg/dl) or high cholesterol (145 mg/dl). Piglets were fed for 2 weeks. Male piglets in the restricted low cholesterol group gained significantly less weight per milliliter of formula than the restricted high cholesterol males. No effect was observed in the females. Microvillus membrane lactase activity was greater in males fed a high versus low cholesterol diet. Intestinal and hepatic HMG-CoA reductase activities and serum lipid profiles showed a trend toward compensation for dietary cholesterol deprivation but did not differ statistically between the cholesterol-fed versus -deprived groups. It is concluded that dietary cholesterol deprivation in the male neonatal pig causes alterations in growth, but no other statistically significant responses were detectable in this study. 相似文献