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Comparative sequence analysis of the hemagglutinin (HA) genes of a highly virulent H5N8 virus isolated from turkeys in Ireland in 1983 and a virus of the same subtype detected simultaneously in healthy ducks showed only four amino acid differences between these strains. Partial sequencing of six of the other genes and antigenic similarity of the neuraminidases established the overall genetic similarity of these two viruses. Comparison of the complete sequence of two H5 gene sequences and partial sequences of other virulent and avirulent H5 viruses provides evidence for at least two different lineages of H5 influenza virus in the world, one in Europe and the other in North America, with virulent and avirulent members in each group. In vivo studies in domestic ducks showed that all of the H5 viruses that are virulent in chickens and turkeys replicate in the internal organs of ducks but did not produce any disease signs. Additionally, both viruses isolated from turkeys and ducks in Ireland were detected in the blood. These studies provide the first conclusive evidence for the possibility that fully virulent influenza viruses in domestic poultry can arise directly from viruses in wild aquatic birds. Studies on the cleavability of the HA of virulent and avirulent H5 viruses showed that the principles established for H7 viruses (F. X. Bosch, M. Orlich, H. D. Klenk, and R. Rott, 1979, Virology 95, 197-207; F. X. Bosch, W. Garten, H. D. Klenk, and R. Rott, 1981, Virology 113, 725-735) also apply to the H5 subtype. These are (1) only the HAs of virulent influenza viruses were cleaved in tissue culture in the absence of trypsin and (2) virulent H5 influenza viruses contain a series of basic amino acids at the cleavage site of the HA, whereas avirulent strains contain only a single arginine with the exception of the avirulent Chicken/Pennsylvania virus. Thus, a series of basic amino acids at the cleavage site probably forms a recognition site for the enzyme(s) responsible for cleavage.  相似文献   
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The study was undertaken to determine whether PIVH and PVL in neonates are related to cord blood TNF levels and chorioamnionitis. The study material consisted of 54 neonates--31 preterm and 23 full-term. 39 of those babies were born to mothers with clinical signs of intrauterine infection, but only in 20 cases histologic chorioamnionitis were recognised. In the whole study newborns brain ultrasound examination was taken during the first 3 days of life. Abnormal head ultrasound (PIVH--17 cases or PVL--6 cases) was diagnosed in 23 babies. That was found that brain damage, recognised during neonatal period, was mainly connected with prematurity and signs of maternal infections but not with cord blood TNF levels. We conclude that prolongation of pregnancy as well as early recognition and proper treatment of intrauterine infection can prevent PIVH and PVL in neonates.  相似文献   
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The 9th International Workshop on Adverse Drug Reactions and Lipodystrophy in HIV provided a forum for the presentation of basic and clinical research focused on the pathogenesis and management of lipodystrophy and other adverse events associated with antiretroviral therapy. New data were reported on the contribution of both antiretroviral therapy and HIV infection itself on the development of metabolic abnormalities in patients with lipodystrophy, including insulin resistance and dyslipidaemia, which are associated with an increased risk of diabetes and cardiovascular disease. In addition, an emerging role of HIV and antiretroviral therapy in bone, liver and kidney disease were highlighted. A major focus of the data presented in these areas concerned the identification and evaluation of risk factors and appropriate surrogate markers for defining cardiovascular disease risk as well as other outcomes of long-term treatment. The complexity of defining such risk factors was underscored by data describing the impact of race, age and gender in the progression of metabolic disease and related complications among different HIV-infected populations. Finally, advances in the development of pharmacovigilance reporting systems in resource-limited settings and their impact upon healthcare policies and the provision of patient care were also described.  相似文献   
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Exposure of influenza virus haemagglutinin to pH 5 results in conformational changes occurring in the molecule which are accompanied by antigenic modifications. Furthermore, isolated haemagglutinin (HA) at a concentration of 0.1 nM undergoes dissociation from the trimeric to a monomeric form when exposed to pH 5. Whether present on intact virus or as the isolated monomer, each form of haemagglutinin from pH 5 exhibits similar alterations in antigenic characteristics. These forms of HA show modifications in the antigenic sites located in the hinge (site C), tip (site B) and subunit interface (site D) regions. Whereas binding of monoclonal antibodies recognizing the tip and interface is abrogated or diminished, binding of antibodies to the hinge region is greatly enhanced following exposure of virus or the monomeric form of HA to pH 5.  相似文献   
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A gene for autosomal recessive familial hyperinsulinism (HI)(OMIM: 256450 [OMIM] ), a neonatal metabolic disease characterized byinappropriate insulin secretion In the presence of severe hypoglycemia,was recently mapped to a 6.6 cM interval between the markersD11S926 and D11S928 on chromosome lip In 15 families (1). inthe current study we evaluated six additional families and fivenew markers, and further localized the gene between D11S419and D11S131O. Using genotype data from CEPH Version 7 and datagenerated from this study, this region was estimated to be 0.8cM in length. Significant linkage disequilib rium between markersand the HI gene was observed over a region of 10.3 cM (11pter-D11S926-D11S1308-11pcen)for Ashkenazi Jewish chromosomes. Haplotype analysis showedthat 12 of 36 HI chromosomes, versus one of 36 non-HI chromosomes, bore a specific haplotype for D11S419-D11 S902-D11 S921(p<0.0007), strongly suggesting a founder eftect In thisethnic group.  相似文献   
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OBJECTIVE: The original tension-free vaginal tape (TVT) method, described by Ulmsten et al., routinely uses local anaesthesia during the procedure. Since the anaesthetic effect after local application of lidocaine hydrochloride was not always satisfactory we decided to introduce the spinal anaesthesia during this operation. The aim of the present study was to compare local and spinal anaesthesia with respect to their efficacy and safety in the TVT procedure. METHODS: 103 women, with objectively confirmed stress urinary incontinence, were randomised into the study. Sixty-seven women were anaesthetised locally and 36 patients spinally. All TVT procedures were performed as originally described. Objective assessment of the influence of anaesthesia on intra-abdominal pressure at rest and during the cough test was done using a rectal catheter and a central venous pressure manometer. The efficacy of the TVT procedure was based on a gynaecological examination with a cough test and a three-degree subjective scale: complete cure, improvement or failure. RESULTS: The success of the TVT procedure performed under local anaesthesia is comparable with that achieved under spinal analgesia (p=0.42). The number of complications that occurred in the two groups does not differ significantly (p=0.57). CONCLUSIONS: Spinal anaesthesia impairs the ability to cough effectively during the TVT procedure. However, the efficacy and safety of the operations performed under this type of anaesthesia are comparable with the efficacy and safety of operations done under local anaesthesia.  相似文献   
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Surgical clipping has been considered for years a "golden standard" in the treatment of middle cerebral artery (MCA) aneurysms. The recent development of materials and endovascular techniques has permitted the use of embolization for the treatment of intracranial aneurysms regardless of their locations and size. In 30 patients with 32 MCA aneurysms (group I) the endovascular approach with GDC-10 coils was used, while in other 30 patients with 31 aneurysms (group II) surgical clipping was performed. On completion of the diagnostic process the patients were randomly assigned either to the endovascular or microsurgical treatment. Group I: 21 (70%) embolization procedures were carried out, while in 9 (30%) cases with 10 aneurysms embolisation was impossible or regarded as too risky due to various causes. The total occlusion of aneurysm SAC was achieved in 17 (77%) aneurysms, subtotal in 5 (23%). The morbidity rate was 8%, mortality-0%. Group II: Microsurgical clipping was performed in 27 (90%) cases, 3 (10%) patients were disqualified from treatment due to their poor clinical status. An excellent technical result was achieved in 24 (86%) patients, in 4 (14%) cases the neck remnant was observed in control angiography. The morbidity rate was 14%, mortality-0%.  相似文献   
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