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排序方式: 共有171条查询结果,搜索用时 15 毫秒
11.
12.
Kyphoplasty versus vertebroplasty to increase vertebral body height: a cadaveric study 总被引:5,自引:0,他引:5
PURPOSE: To prospectively compare the vertebral height restoration achieved with kyphoplasty and vertebroplasty in fresh cadavers by using multi-detector row computed tomography (CT). MATERIALS AND METHODS: Institutional review board approval was not required because the donors had registered in and consented to an anatomic gift program prior to their death. Thirty-seven vertebrae were harvested from four donated cadavers of elderly female individuals (mean age, 82 years; age range at death, 73-87 years). The vertebrae were dissected free of the surrounding muscles and imaged with multi-detector row CT. Compression fractures were induced, and the vertebrae were again imaged. The vertebrae were randomized to be treated with kyphoplasty (n = 19) or vertebroplasty (n = 18) and were then imaged at multi-detector row CT. The anterior, central, and posterior vertebral body heights and wedge angles were measured in the midsagittal plane of the reformatted images. The amount of cement injected was determined by weighing the vertebrae before and after treatment. The statistical significance of changes in vertebral body height, wedge angle, and weight with the two treatment techniques was evaluated with the independent t test or Mann-Whitney U test. RESULTS: The increase in vertebral height was greater with kyphoplasty than with vertebroplasty (5.1 mm vs 2.3 mm, respectively; P < .05). The original vertebral height was restored in 93% of vertebrae with kyphoplasty and in 82% with vertebroplasty (P < .05). There was a greater decrease in wedge angle with kyphoplasty than with vertebroplasty (3.1 degrees vs 1.6 degrees, respectively); however, this difference was not significant (P > .05). There was no significant difference in the amount of cement injected with kyphoplasty and vertebroplasty (P > .05). CONCLUSION: Kyphoplasty increased vertebral body height more than vertebroplasty in this model of acutely created fractures in fresh cadaver specimens. 相似文献
13.
Rats treated with the neuroepileptic drug, kainic acid, exhibit a specific regional pattern of neurodegeneration 24 h following
onset of acute limbic status epilepticus. At 24 h post-seizure, the areas undergoing neurodegeneration also exhibit substantial
amounts of the neuropeptide corticotropin-releasing factor (CRF) which is not present under normal conditions. In experimental
brains, CRF is localized immunocytochemically to cells and densely labeled fibers in areas with neurodegeneration. Networks
of CRF fibers closely surround moribund neurons staining intensely for acid fuchsin. Acid fuchsin, an acidophilic dye, is
used routinely as a marker for irreversible neuronal injury, and acid fuchsin-positive neurons are identified in specific
areas affected by kainic neurotoxicity. Evidence exists in the literature that CRF functions in brain as a excitatory neurotransmitter/neuromodulator.
Under certain pathological conditions (i.e., seizures, brain trauma, ischemia), it has been postulated that CRF could act
as an neurotoxic agent. This study provides anatomical evidence that CRF may function following seizures as an neurotoxin
because of the close proximity of CRF-labeled fibers to degenerating neurons.
Received: 19 October 1998 / Revised: 3 February 1999 / Accepted: 24 March 1999 相似文献
14.
Katja Nelson DDS Detlef Hildebrand DMD DT Juergen Mehrhof MDT 《Journal of prosthodontics》2008,17(7):591-595
This article describes a method of fabricating a fixed retrievable implant‐retained prosthesis based on electroforming. This method combines the advantages of both the cement‐ and screw‐retained prostheses, including passive fit, ease of fabrication, and retrievability. The absence of visible occlusal screw‐canals adds to its increased esthetic appeal. 相似文献
15.
This report describes the distribution of tyrosine hydroxylase immunoreactive (TH-ir) structures in the brain of the goldfish (Carassius auratus). The localization of TH-ir cell groups revealed by immunocytochemical techniques is largely in accordance with catecholamine distribution previously reported in teleosts by using monoamine fluorescence; however, in the telencephalon and diencephalon, several new cell groups are elucidated. In the telencephalon, TH-ir cell bodies are observed in the olfactory bulb, area ventralis telencephali, and the central zone of the area dorsalis telencephali. TH-ir fibers and terminals are moderately dense throughout the telencephalon except for a sparse innervation of the area dorsalis, pars medialis. Immunostained cells are present in the suprachiasmatic nucleus and magnocellular and parvicellular components of the preoptic nucleus. Immunoreactive fibers from preoptic cells can be traced caudally in two main tracts to the infundibulum. Dense immunoreactivity around cells in the pituitary provides anatomical support for catecholamine involvement in the neuroendocrine axis probably via preopticohypophysial connections. At middiencephalic levels, immunoreactive cells are present in the ventral thalamus, nucleus pretectalis periventricularis, pars ventralis, and paraventricular organ pars anterioris. In the caudal diencephalon, TH-ir cells are seen within the posterior tuberal nuclei and dorsal to posterior recess. No immunostained cells are observed in the midbrain. In the hindbrain, tyrosine hydroxylase containing cells comprise three groups similar to that described using Falck-Hillarp histofluorescence (Parent et al., '78), i.e., isthmal, central medullary, and medullospinal groups. Tyrosine hydroxylase immunoreactivity is interpreted as evidence for the presence of catecholamines and not only provides an anatomical basis for the functional significance of catecholamines in teleosts, but may be useful in elucidating homologous structures in tetrapod vertebrates, although certain sites of immunoreactivity may prove to be unique to teleosts. 相似文献
16.
Schizencephaly: diagnosis and progression in utero 总被引:2,自引:0,他引:2
Schizencephaly is an unusual condition of obscure etiology. Most theories of pathogenesis postulate an in utero insult leading to maldevelopment rather than destruction of brain. The cause has most often been described as vascular or idiopathic dysgenesis. The authors report a case in which two in utero ultrasound (US) examinations performed at 31 and 36 menstrual weeks demonstrated progressive deterioration of the relatively narrow, symmetrical clefts connecting the lateral ventricles with the subarachnoid space into broad defects that corresponded to the entire distribution of the middle cerebral arteries. The findings in this case document progressive destruction of brain tissue in utero and are consistent with a vascular cause rather than a failure of formation of portions of the cerebral mantle. 相似文献
17.
18.
Chen YC; Wang CH; Su IJ; Hu CY; Chou MJ; Lee TH; Lin DT; Chung TY; Liu CH; Yang CS 《Blood》1989,74(1):388-394
Among 354 adult patients with either hematological malignancy or aplastic anemia, eight were positive for anti-HTLV-I antibodies; six of eight had received multiple transfusions. There was an approximately 3.5-fold increase (P less than .001) of HTLV-I seropositivity in the patients with hematologic disease (8 of 354, 2.23%) compared to the healthy adults older than 20 years (34 of 5252, .65%). Two hematological patients, one with Hodgkin's disease and one with acute promyelocytic leukemia, were found to be positive for HTLV-I, and developed and died of adult T-cell leukemia/lymphoma (ATL) subsequently. Both were long-term survivors of the primary disease and had received multiple transfusions. The latent period from blood transfusion to onset of ATL was 6 months and 11 years, respectively. Immunocompromised patients, who were seropositive for HTLV-I, may be at increased risk for ATL compared to healthy carriers of HTLV-I, and the latent period may be shorter. 相似文献
19.
Background
The pathogenesis of HIV/hepatitis C virus (HCV) coinfection is poorly understood. We examined markers of oxidative stress, plasma antioxidants and liver disease in HIV/HCV‐coinfected and HIV‐monoinfected adults.Methods
Demographics, medical history, and proof of infection with HIV, hepatitis A virus (HAV), hepatitis B virus (HBV) and HCV were obtained. HIV viral load, CD4 cell count, complete blood count (CBC), complete metabolic panel, lipid profile, and plasma concentrations of zinc, selenium, and vitamins A and E were determined. Malondialdehyde (MDA) and glutathione peroxidase concentrations were obtained as measures of oxidative stress. Aminotransferase to platelet ratio index (APRI) and fibrosis index (FIB‐4) markers were calculated.Results
Significant differences were found between HIV/HCV‐coinfected and HIV‐monoinfected participants in levels of alanine aminotransferase (ALT) (mean±standard deviation: 51.4±50.6 vs. 31.9±43.1 U/L, respectively; P=0.014), aspartate aminotransferase (AST) (56.2±40.9 vs. 34.4±30.2 U/L; P<0.001), APRI (0.52±0.37 vs. 0.255±0.145; P=0.0001), FIB‐4 (1.64±.0.91 vs. 1.03±0.11; P=0.0015) and plasma albumin (3.74±0.65 vs. 3.94±0.52 g/dL; P=0.038). There were no significant differences in CD4 cell count, HIV viral load or antiretroviral therapy (ART) between groups. Mean MDA was significantly higher (1.897±0.835 vs. 1.344± 0.223 nmol/mL, respectively; P=0.006) and plasma antioxidant concentrations were significantly lower [vitamin A, 39.5 ± 14.1 vs. 52.4±16.2 μg/dL, respectively (P=0.0004); vitamin E, 8.29±2.1 vs. 9.89±4.5 μg/mL (P=0.043); zinc, 0.61±0.14 vs. 0.67±0.15 mg/L (P=0.016)] in the HIV/HCV‐coinfected participants than in the HIV‐monoinfected participants, and these differences remained significant after adjusting for age, gender, CD4 cell count, HIV viral load, injecting drug use and race. There were no significant differences in glutathione peroxidase concentration, selenium concentration, body mass index (BMI), alcohol use or tobacco use between groups. Glutathione peroxidase concentration significantly increased as liver disease advanced, as measured by APRI (β=0.00118; P=0.0082) and FIB‐4 (β=0.0029; P=0.0177). Vitamin A concentration significantly decreased (β=?0.00581; P=0.0417) as APRI increased.Conclusion
HIV/HCV coinfection is associated with increased oxidative stress and decreased plasma antioxidant concentrations compared with HIV monoinfection. Research is needed to determine whether antioxidant supplementation delays liver disease in HIV/HCV coinfection.20.