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排序方式: 共有529条查询结果,搜索用时 15 毫秒
1.
神经生长因子对小鼠突触体内Ca^2+水平的调节作用 总被引:4,自引:1,他引:3
观察了多次海马内微注射NGF对小鼠突触体内游离钙水平的影响,并在离体情况下观察NGF对EGTA和CaCl2分别造成突触体内低钙和高钙状态的调节作用。结果如下:(1)在体实验表明,一定剂量的NGF可显著降低老年小鼠海马突触体内游离钙水平(P<005);(2)离体实验表明,当突触体游离钙水平降低时,适当剂量的NGF具有升高游离钙水平的作用;而突触体内游离钙水平升高时,则NGF有降低游离钙水平的作用。提示NGF对游离钙水平的双向调节作用可能是NGF改善老年性记忆衰退的作用机制。 相似文献
2.
Damage control surgery for abdominal trauma. 总被引:5,自引:0,他引:5
OBJECTIVE: To review the physiology, indications, technical aspects, morbidity, and mortality of damage control surgery. DESIGN: Retrospective study of published papers. SETTING: Teaching hospital, United Arab Emirates. INTERVENTIONS: A MEDLINE search on damage control surgery for the years 1981-2001. Further articles were retrieved from the references of the original articles. RESULTS: The indications for damage control surgery are: the need to terminate a laparotomy rapidly in an exsanguinating, hypothermic patient who had developed a coagulopathy and who is about to die on the operating table; inability to control bleeding by direct haemostasis; and inability to close the abdomen without tension because of massive visceral oedema and a tense abdominal wall. The principles of damage control surgery are: Phase I: laparotomy to control haemorrhage by packing; shunting, or balloon tamponade, or both; control of intestinal spillage by resection or ligation of damaged bowel, or both. Phase II: physiological resuscitation to correct hypothermia, metabolic acidosis, and coagulopathy. Phase III: planned reoperation for definitive repair. Damage control surgery is appropriate in a small number of critically ill patients who are likely to require substantial hospital resources; it has a high mortality (mean 45%, range (10%-69%). CONCLUSION: Damage control surgery offers a simple effective alternative to the traditional surgical management of complex or multiple injuries in critically injured patients. Phases I and II can be done at a rural hospital before transfer to a major trauma centre for definitive repair. 相似文献
3.
OBJECTIVE: To test the hypothesis that the oxidation of proteins is part of the mechanism of proteolysis in catabolic states. DESIGN: Prospective, observational study. SETTING: Critical care unit at a university teaching hospital, New Zealand. PATIENTS: 13 patients (6 male, 7 female; median age 61, range 26-76 years) who were admitted to the Department of Critical Care Medicine at Auckland Hospital with a diagnosis of severe sepsis. The median APACHE II score during the first 24 hours after admission was 22 (range 15-34). Control values of protein carbonyl in plasma were established in 15 healthy volunteers. INTERVENTIONS: We made serial measurements of total body protein (by neutron activation analysis) and plasma protein carbonyl (by ELISA) concentrations over a period of 10 days. MAIN OUTCOME MEASURE: Plasma protein carbonyl concentration and total body protein. RESULTS: The total amount of body protein decreased significantly over the 10 days (p < 0.001). Plasma protein carbonyl concentrations were significantly higher in the septic patients than in the control group throughout the study period (p < 0.0001). There was a significant reduction in plasma protein carbonyl concentration over the study period (p < 0.008). The early increase in the concentration of protein carbonyl formation was followed by an ongoing loss of body protein. There was a significant positive correlation between total body protein and plasma protein carbonyl (p < 0.03). CONCLUSIONS: Severe sepsis results in oxidation of plasma proteins and this precedes and is related to the loss of body protein. 相似文献
4.
MY Mancao LJ Sindel PH Richardson FM Silver 《Acta paediatrica (Oslo, Norway : 1992)》1996,85(1):118-120
Croup is an acute infectious illness usually occurring in children; it is characterized by brassy cough and stridor. The main pathogens include mainly parainfluenza and influenza viruses. Recently there have been reports of prolonged croup caused by the herpes simplex viruses. We report two cases of prolonged croup due to herpes simplex types 1 and 2. We also review and summarize the reported pediatric cases of herpetic croup. 相似文献
5.
Duncan WC; Illingworth PJ; Young FM; Fraser HM 《Human reproduction (Oxford, England)》1998,13(9):2532-2540
The molecular mechanisms involved in luteolysis are still unclear in the
primate. This study aimed to investigate the effect of induced luteolysis
on the ovarian luteinizing hormone (LH) receptor and the steroidogenic
enzyme, 3beta-hydroxysteroid dehydrogenase (3beta-HSD) in the marmoset
monkey. Luteolysis was induced in the mid-luteal phase either directly by
systemic prostaglandin F2alpha (PGF2alpha), or indirectly by LH withdrawal
using systemic gonadotrophin releasing hormone antagonist (GnRHant)
treatment. The LH receptor was studied by isotopic mRNA in-situ
hybridization and in-situ ligand binding and 3beta-HSD expression was
studied using isotopic mRNA in-situ hybridization and immunohistochemistry.
Induced luteolysis was associated with a reduction in the expression of LH
receptor (P < 0.0001) and 3beta-HSD mRNA, closely followed by a
reduction in the LH receptor (P < 0.05) and 3beta-HSD protein
concentrations within 24 h. There were no differences in the findings
whether luteolysis was induced with PGF2alpha or GnRHant. This study shows
that disparate mechanisms to induce luteolysis in the primate result in an
identical rapid loss of the LH receptor and 3beta-HSD. In conclusion,
induced luteolysis leads to rapid loss of the steroidogenic pathway in
luteal cells.
相似文献
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9.
Transition metal complexes containing vanadium IV have been shown to
modulate the cellular redox potential and catalyse the generation of
reactive oxygen intermediates (ROI). Since sperm function is exquisitely
susceptible to ROI, we examined the effects of stable chelate complexes of
vanadocenes on human sperm motility. We synthesized seven structurally
distinct chelate complexes of bis(cyclopentadienyl)vanadium(IV) with
bidentate ligands [i.e. vanadocene acetylacetonato monotriflate (VDacac),
vanadocene hexafluoro acetylacetonato monotriflate (VDHfacac), vanadocene
N-phenyl benzohydroxamato monotriflate (VDPH), vanadocene acethydroxamato
monotriflate (VDH), vanadocene catecholate (VDCAT), vanadocene bipyridino
ditriflate (VDBPY), and vanadocene dithiocarbamate monotriflate (VDDTC)],
and evaluated their spermicidal activity using computer-assisted sperm
analysis (CASA; Hamilton-Thorne). All seven chelate complexes of vanadocene
elicited potent spermicidal activity at micromolar concentrations (EC50
values: 3.9-106 microM) without affecting the sperm acrosome integrity. The
catecholate and acetylacetonate complexes of vanadocene were the most
active and the bipyridyl complex the least active with an order of efficacy
VDCAT > VDacac > VDDTC > VDPH > VDH > VDHfacac > VDBPY.
The spermicidal activity of chelate complexes of vanadocenes was rapid and
irreversible since the treated spermatozoa underwent apoptosis, as
determined by the flow cytometric analysis of mitochondrial membrane
potential, surface annexin V binding assay, in-situ nick-end labelling of
sperm nuclei, and confocal laser scanning microscopy. These results provide
unprecedented evidence that chelate complexes of vanadocene with bidentate
ligands have spermicidal and apoptosis inducing properties. These
vanadocene complexes, especially VDacac, may be useful as contraceptive
agents.
相似文献
10.
Ultrasonography has been proposed as a screening method for blunt abdominal trauma, but its specific role in comparison with other diagnostic modalities has yet to be defined. The aim of the present retrospective study was to compare the results of ultrasonography and CT of the abdomen in blunt trauma in a district general hospital. The hospital records of 25 patients who were admitted with blunt abdominal trauma to Southland Hospital, Invercargill, New Zealand, between January 1991 and November 1996 and who had both ultrasound and CT of the abdomen within 48 h of admission were reviewed. Ultrasound missed seven lesions in seven patients (7/25, 28%) compared with CT. Three of these were intestinal lesions that needed laparotomy. Ultrasound had a usefulness index of 1, 0.76, 0.72, 0.69 and 0, respectively, for detecting lesions of the kidneys, free intraperitoneal fluid, the liver, the spleen, and intestines. Although ultrasound can be used as an initial screening method for blunt abdominal trauma, CT is still the imaging modality of choice for detecting intra-abdominal lesions for stable patients in a district general hospital. 相似文献