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排序方式: 共有362条查询结果,搜索用时 15 毫秒
91.
92.
Ahmed Abdulrahman K. Sayad Reem Mahmoud Islam A. EL-Monem Aya M. Abd Badry Salma H. Ibrahim Islam H. Hafez Mahmoud HR El-Mokhtar Mohamed A. Sayed Ibrahim M. 《Journal of neurovirology》2022,28(2):189-200
Journal of NeuroVirology - COVID-19 pandemic spreads worldwide, with more than 100 million positive cases and more than 2 million deaths. From the beginning of the COVID-19 pandemic, several... 相似文献
93.
Cytokines in inflammatory malignant fibrous histiocytoma presenting with leukemoid reaction 总被引:5,自引:0,他引:5
Inflammatory malignant fibrous histiocytomas (IMFH) are rare tumors and are frequently associated with leukocytosis. In rare cases, leukemoid reactions were attributed to tumor production of unidentified hematopoietic factors. In this study, we used immunohistochemical techniques to show cytokine immunoreactivity in the malignant cells of two cases of IMFH presenting with leukemoid reactions and compared them with two malignant fibrous histocytomas, noninflammatory type. All four tumors stained positively for stem cell factor (SCF), granulocyte colony-stimulating factor (G-CSF), interleukin-2 (IL-2), IL-4, IL-5, interferon-alpha (IFN-alpha), and insulin-like growth factor-I. Other cytokines detected only in the two IMFH included IL-6, IL-7, IL-8, IFN- gamma, and keratinocyte growth factor. Granulocyte-macrophage-CSF, IL- 3, and transforming growth factor-beta staining was present in one of the two IMFH tumors and was not present in the noninflammatory tumors. The immunohistochemical staining was localized to the malignant cells, suggesting deregulated cytokine expression consistent with their monocytic/histocytic origin. Expression of certain cytokines in the IMFH may account for the local inflammatory infiltrate, tumor fibrosis, and the aggressive nature of the malignant cells. We also detected elevated serum levels of SCF, G-CSF, IL-6, and tumor necrosis factor in one or both of the IMFH patients. These latter observations may explain the bone marrow hypercellularity and other paraneoplastic symptoms, including fever, malaise, and weight loss, observed in both patients. Different cytokines present in the two IMFH tumors appear to be responsible for the eosinophilic leukemoid reaction observed in one case and for the granulocytic leukemoid reaction observed in the other patient. They may also be responsible for expansion of the tumor-cell population, fibroblast proliferation, and enhanced secretion of extracellular collagen. 相似文献
94.
Severe factor VII deficiency caused by mutations abolishing the cleavage site for activation and altering binding to tissue factor 总被引:6,自引:1,他引:6
Chaing S; Clarke B; Sridhara S; Chu K; Friedman P; VanDusen W; Roberts HR; Blajchman M; Monroe DM; High KA 《Blood》1994,83(12):3524-3535
Factor VII (F.VII) is a vitamin-K-dependent serine protease required in the early stages of blood coagulation. We describe here a patient with severe F.VII deficiency, with a normal plasma F.VII antigen level (452 ng/mL) and F.VII activity less than 1%, who is homozygous for two defects: a G-->A transition at nucleotide 6055 in exon 4, which results in an Arg-->Gln change at amino acid 79 (R79Q); and a G-->A transition at nucleotide 8961 in exon 6, which results in an Arg-->Gln substitution at amino acid 152 (R152Q). The R79Q mutation occurs in the first epidermal growth factor (EGF)-like domain, which has previously been implicated in binding to tissue factor. The R152Q mutation occurs at a site (Arg 152-Ile 153) that is normally cleaved to generate activated F.VII (F.VIIa). Analysis of purified F.VII from patient plasma shows that the material cannot be activated by F.Xa and cofactors. In addition, in an in vitro binding assay using relipidated recombinant tissue factor, patient plasma showed markedly reduced binding to tissue factor at all concentrations tested. In an effort to separate the contributions of the two mutations, three recombinant variants, wild-type, R79Q, and R152Q, were prepared and analyzed. The R152Q variant had markedly reduced activity in a clotting assay, whereas R79Q showed a milder, concentration-dependent reduction. The R152Q variant exhibited nearly normal binding in the tissue factor binding assay, whereas the R79Q variant had markedly reduced binding. The time course of activation of the R79Q variant was slowed compared with wild-type. Our results suggest that the first EGF-like domain is required for binding to tissue factor and that the F.VII zymogen lacks activity and requires activation for expression of biologic activity. 相似文献
95.
We have investigated the periodic acid Schiff (PAS) Coomassie staining ratio of the human factor VIII/von Willebrand factor (fVIII/vWf) protein. The PAS-Coomassie staining ratio is consistent over 8 days. The PAS-Coomassie ratio of fVIII/vWf protein purified from different starting materials does not appear to be significantly different. The PAS stain can detect as little as 300 ng of carbohydrate in the fVIII/vWf protein. Desialation did not affect the PAS-Coomassie ratio, while removal of penultimate galactose resulted in a marked reduction in the PAS-Coomassie ratio. This reduction was further accentuated with the removal of N-acetylglucosamine. The smaller multimers of the fVIII/vWf protein have a reduced sialic acid and PAS-Coomassie staining ratio. This difference does not appear to be related to the sialic acid deficiency but may be related to the distribution or organization of the carbohydrate moieties on the smaller fVIII/vWf multimers. 相似文献
96.
Background: Myopathy of metabolic origin in childhood occurs due to a variety of conditions. Pompe's Disease also known as Glycogen storage disease Type II, is a rare storage disorder with clinical presentation akin to spinal muscular atrophy. 相似文献
97.
M. B. WALLACE A. MEINING M. I. CANTO P. FOCKENS S. MIEHLKE T. ROESCH C. J. LIGHTDALE H. POHL D. CARR‐LOCKE M. LÖHR E. CORON B. FILOCHE M. GIOVANNINI J. MOREAU C. SCHMIDT R. KIESSLICH 《Alimentary pharmacology & therapeutics》2010,31(5):548-552
Aliment Pharmacol Ther 31 , 548–552
Summary
Background Confocal laser endomicroscopy (CLE) is rapidly emerging as a valuable tool for gastrointestinal endoscopic imaging. Fluorescent contrast agents are used to optimize imaging with CLE, and intravenous fluorescein is the most widely used contrast agent. Fluorescein is FDA‐cleared for diagnostic angiography of the retina. For these indications, the safety profile of fluorescein has been well‐documented; however, to date, fluorescein is not cleared for use with CLE. Aims To estimate the rate of serious and total adverse events attributable to intravenous fluorescein when used for gastrointestinal CLE. Methods We performed a cross sectional survey of 16 International Academic Medical Centres with active research protocols in CLE that involved intravenous fluorescein. Centres using i.v. fluorescein for CLE who were actively monitored for adverse events were included. Results Sixteen centres performed 2272 gastrointestinal CLE procedures. The most common dose of contrast agent was 2.5–5 mL of 10% sodium fluorescein. No serious adverse events were reported. Mild adverse events occurred in 1.4% of individuals, including nausea/vomiting, transient hypotension without shock, injection site erythema, diffuse rash and mild epigastric pain. The limitation is that only immediate post procedure events were actively monitored. Conclusions Use of intravenous fluorescein for gastrointestinal CLE appears to be safe with few acute complications. 相似文献98.
M Ghanei Dr Assistant Professor Medicine P Adibi Deputy Manager M Movahedi Resident Doctor for Internal Medicine MA Khami Lecturer of Histology RL Ghasemi Vice Chancellor T Azarm Associate Professor Medicine B Zolfaghari Lecturer of Medical Education HR Jamshidi University Chancellor R Sadri Computer Consultant 《Public health》1997,111(3):153-156
Background: Iran like other middle east countries has a large number of major thalassaemics. Due to religious restrictions on abortion, the routine prevention of the birth of thalassaemic children by this means is not possible. The aim of this study is to describe an alternative means to prevent the birth of thalassaemic children.Methods: From January 1993 to January 1996, 100 000 people preparing for marriage were screened for the thalassaemia trait, using CBC and HbA2 level measurement. High risk couples were referred for further consultation regarding the disease and the means of its prevention. The proposed actions of the couples regarding thalassaemia prevention were evaluated immediately after consultation and then re-evaluated three months later. Result: After the project had been running for three years the average of high risk couple initially deciding not to marry was 90% and no new cases of thalassemia were detected in the children of the screened population.Conclusion: Where both members of the couple were trait-positive their preferred choice was not to marry, rather than to marry and use other or no methods of preventing a thalassemia affected child being born to them. Cultural and religious ideas can affect such decisions and in some Islamic countries the establishment and use of a genetic counselling centre can help prevent most of new thalassaemia cases. 相似文献
99.
S Dedieu X Canron HR Rezvani M Bouchecareilh F Mazurier R Sinisi M Zanda M Moenner A Bikfalvi S North 《BMC medicine》2010,8(1):19
Background
Amifostine (WR-2721, delivered as Ethyol®) is a phosphorylated aminothiol compound clinically used in addition to cis-platinum to reduce the toxic side effects of therapeutic treatment on normal cells without reducing their efficacy on tumour cells. Its mechanism of action is attributed to the free radical scavenging properties of its active dephosphorylated metabolite WR-1065. However, amifostine has also been described as a potent hypoxia-mimetic compound and as a strong p53 inducer; both effects are known to potently modulate vascular endothelial growth factor (VEGF-A) expression. The angiogenic properties of this drug have not been clearly defined.Methods
Cancer cell lines and endothelial cells were used in culture and treated with Amifostine in order to study (i) the expression of angiogenesis related genes and proteins and (ii) the effects of the drug on VEGF-A induced in vitro angiogenesis.Results
We demonstrated that the treatment of several human cancer cell lines with therapeutical doses of WR-1065 led to a strong induction of different VEGF-A mRNA isoforms independently of HIF-1α. VEGF-A induction by WR-1065 depends on the activation of the eIF2alpha/ATF4 pathway. This up-regulation of VEGF-A mRNA was accompanied by an increased secretion of VEGF-A proteins fully active in stimulating vascular endothelial cells (EC). Nevertheless, direct treatment of EC with amifostine impaired their ability to respond to exogenous VEGF-A, an effect that correlated to the down-regulation of VEGFR-2 expression, to the reduction in cell surface binding of VEGF-A and to the decreased phosphorylation of the downstream p42/44 kinases.Conclusions
Taken together, our results indicate that amifostine treatment modulates tumour angiogenesis by two apparently opposite mechanisms - the increased VEGF-A expression by tumour cells and the inhibition of EC capacity to respond to VEGF-A stimulation.100.
ML Katcher P Agran D Laraque SH Pollack GA Smith HR Spivak M Tenenbein SB Tully 《Pediatrics》1999,103(2):524-526
Proper record-keeping of emergency department visits and hospitalizations of injured children is vital for appropriate patient management. Determination and documentation of the circumstances surrounding the injury event are essential. This information not only is the basis for preventive counseling, but also provides clues about how similar injuries in other youth can be avoided. The hospital records have an important secondary purpose; namely, if sufficient information about the cause and mechanism of injury is documented, it can be subsequently coded, electronically compiled, and retrieved later to provide an epidemiologic profile of the injury, the first step in prevention at the population level. To be of greatest use, hospital records should indicate the "who, what, when, where, why, and how" of the injury occurrence and whether protective equipment (eg, a seat belt) was used. The pediatrician has two important roles in this area: to document fully the injury event and to advocate the use of standardized external cause-of-injury codes, which allow such data to be compiled and analyzed. 相似文献