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21.
22.
Regulation of preproenkephalin (PPE) mRNA was examined in astrocytes cultured from several regions of the neonatal rat brain. Astrocytes from these regions expressed differing levels of PPE mRNA, with higher levels in astrocytes from the hypothalamus followed by frontal cortex and striatum. Further, PPE mRNA was regulated differently in hypothalamic than in striatal glia. Treatment of striatal astrocytes with the beta-adrenergic agonist, isoproterenol, or with agents which directly increased intracellular cAMP (forskolin or 8-bromo-cAMP) elevated levels of PPE mRNA. By contrast, none of these treatments altered levels of PPE mRNA in hypothalamic astrocytes despite increasing cAMP levels 60-fold. These observations indicate that there is striking regional heterogeneity in the expression and regulation of PPE mRNA by astrocytes, suggesting that proenkephalin or its derived peptides help to mediate region-specific brain functions. 相似文献
23.
E. W. Brien Joseph M. Mirra Steven Kessler M. Suen J. K. S. Ho W. T. Yang 《Skeletal radiology》1997,26(4):246-255
It is not uncommon for sarcomatous transformation of giant cell tumor (GCT) of bone to occur after radiation, but rarely
does malignant transformation occur spontaneously, with less than 15 cases reported up to 1995. Only four of these cases have
been documented in detail. We report two additional cases of GCT of bone spontaneously transforming or ”dedifferentiating”
into osteosarcoma without radiation therapy. The first case is absolutely unique and most interesting in that the dedifferentiation
process occurred in one of multiple GCT lung metastases 6 years after successful eradication of a primary tibial tumor. The
right lung was resected due to development of a large tumor, and at pathologic examination, demonstrated several small nodules
of conventional GCT and a much larger, 14-cm mass composed of a mixture of GCT and high-grade osteosarcoma. The second case
involved a physician, who had a large tumor in the sacrum with vague symptoms for 8 years. Open biopsy revealed conventional,
benign GCT of bone with a secondary aneurysmal bone cyst. Complete curettage 2 weeks later revealed, in addition to areas
of conventional, benign GCT a second component of very high grade osteosarcoma. Both patients died less than 1.5 years from
diagnosis. This report of osteosarcomatous transformation of a conventional GCT of bone strengthens the theory that there
is a mesenchymal cell line in GCT that may spontaneously tansform to sarcoma. 相似文献
24.
Henryk Barthel Michael Wiener Claudia Dannenberg Simone Bettin Bernhard Sattler Wolfram H. Knapp 《European journal of nuclear medicine and molecular imaging》1997,24(10):1245-1252
This study addresses the question of whether the normal range for distribution of local cerebral blood flow (lCBF) in adults
can be transferred to the 4- to 15-year-old age group. Twenty-three children (age: 4–15 years; mean 11±3 years, group I) and
10 adults (age: 27–56 years; mean 45±10 years, group II) without evidence of cerebrovascular disease or other brain diseases
underwent technetium-99m ethyl cysteinate dimer single-photon emission tomography. Counts in cortical and subcortical regions
of interest (ROIs) were related to those in cerebellar ROIs (= 100%). Relative cortical activity in group I exceeded that
in group II, particularly in left parietal (107.6%±9.8% vs 84.1%±12.4%), left frontal (97.7%±6.7% vs 79.4%±8.9%) and left
temporal areas (99.7%±7.4% vs 84.9%±10.1%) and in the cingulate cortex (112.1%±9.1% vs 95.9%±10.1%, P<0.05). Cerebral activity uptake per injected dose was inversely correlated with age in 19 children of group I (r = –0.77, P<0.001). In group I, there was also an inverse correlation between age and the relative local count density in the parietal
(r = –0.42 to –0.57), frontal (r = –0.48), temporal (r = –0.42 to –0.58) and occipital cortex (r = –0.44). In these cortical regions relative counts differed when subgroups of children aged 4–10 and 11–15 years were analysed.
It is concluded that there are systematic differences between 4- to 15-year-old children and adults with regard to normal
lCBF. Diagnostic use of perfusion agents has to consider age-adjusted normal flow maps; normal ranges should be determined
separately for the age groups 4–10 and 11–15 years.
Received 23 March and in revised form 11 July 1997 相似文献
25.
Tim Strate Claus Schneider Emre Yekebas Wolfram T Knoefel Christian Bloechle Jakob R Izbicki 《Journal of investigative surgery》2003,16(1):13-21
This study was devised to identify sepsis-relevant parameters that early and reliably predict a lethal outcome in intra-abdominal sepsis. In 18 Duroc pigs, peritonitis was induced through standardized gastrotomy. Twelve hours later the defect was oversewn and the abdominal cavity lavaged thoroughly. Sepsis relevant parameters were measured before initiating therapy, and 30 min later animals were extubated and observed for a period of 6 days under adequate analgesia with free access to water and food. All parameters were correlated with survival postoperatively. In the treatment group, 7 out of 18 pigs (39%) died within the observation period. Endotoxin level at 30 min after initiation of therapy [17.9 EU/mL (+/- 12.1) vs. 110.9 EU/mL (+/- 21); p <.001] and Delta pHi [0.015 (+/- 0.011) vs. -0.039 (+/- 0.013); p =.016] were identified as the two parameters with highest predictive power regarding mortality in a multivariate analysis. In conclusion measurement of endotoxin and gastric tonometry should gain wider clinical application in septic patients. 相似文献
26.
27.
E J de Marchena R G Trohman A R Palomo R J Myerburg K M Kessler 《Catheterization and cardiovascular diagnosis》1988,15(3):169-172
Clinical, angiographic, and pathologic data support the contention that atherosclerosis, platelet aggregation, and coronary vasomotility work in unison to cause coronary thrombosis, which in turn leads to myocardial infarction. A patient is described in whom, 2 months after an acute myocardial infarction, inducible coronary artery spasm and a nonocclusive thrombus were angiographically demonstrated at the site of a minimal atherosclerotic narrowing in the infarction-related vessel. This report, to the best of our knowledge, is the first time that these three pathophysiologic mechanisms have been shown, in vivo, to be occurring concomitantly in an infarct-related vessel. Documentation of the unified occurrence of these phenomena support the current concept of the pathophysiology of myocardial infarction. 相似文献
28.
Generation of volatile hydrocarbons from amino acids and proteins by an iron/ascorbate/GSH system 总被引:1,自引:0,他引:1
Incubation of free, but not of peptide-bound methionine in an iron/ascorbate system resulted in ethylene generation, which was inhibited by glutathione. Leucine and isoleucine, however, when incubated in an iron/ascorbate/GSH system, released small amounts of propane and ethane, respectively. Peptide-bound leucine additionally yielded butane, as did bovine serum albumin or casein. Hydrocarbon generation from amino acids was inhibited by hydroxyl radical scavengers, but catalase and superoxide dismutase were more efficient. Additionally, ethane and propane generation in this system was optimal at pH 6.2 suggesting the involvement of protonated superoxide besides OH-radicals which attack the side chains of Leu and Ile and very probably produce carbon-centered radicals, which should abstract a hydrogen atom from the thiol group of GSH resulting in the formation of saturated hydrocarbons. 相似文献
29.
Korchounov A. Kessler K. R. Yakhno N. N. 《世界核心医学期刊文摘》2006,2(5):33-33
目的:本文旨在确定影响原发性帕金森病(IPD)患者自主神经功能障碍严重程度的人口统计学或疾病相关因素。方法:532例年龄为55~75岁的IPD患者纳入本研究。采用自主神经功能障碍量表(A D S)对自主神经功能障碍的严重程度进行评估。另外,记录影响自主神经功能障碍严重程度的人口统 相似文献
30.
Frequency of in vitro resistance of Pseudomonas aeruginosa to cefepime, ceftazidime, and cefotaxime. 总被引:7,自引:5,他引:2 下载免费PDF全文
J Fung-Tomc E Huczko M Pearce R E Kessler 《Antimicrobial agents and chemotherapy》1988,32(9):1443-1445
The selection frequencies of cefepime (BMY 28142), ceftazidime, and cefotaxime resistance among Pseudomonas aeruginosa strains were determined. Cefepime-resistant mutants were not selected by cefepime (frequency, less than 10(-11)). Ceftazidime- and cefotaxime-resistant mutants were isolated at frequencies of 10(-5) to 10(-10) and were often cross-resistant. However, cefepime resistance among ceftazidime- and cefotaxime-resistant mutants was rare. Selected mutants resistant to cefepime constitutively produced 40- to 450-fold more beta-lactamase than did the parent strain. 相似文献