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1.
Kaposi's sarcoma-associated herpesvirus (KSHV) is the primary,etiological agent of Kaposi's sarcoma, primary effusion lymphoma and muticentric Castleman's disease. In common with the other herpesviruses, KSHV exhibits both latent and lyric life cycles, both of which are characterized by distinct gene expression profiles and programs. KSHV encodes proteins which play essential roles in the inhibition of host adaptive and innate immunity, the inhibition of apoptosis, and the regulation of the cell cycle. KSHV also encodes several proteins which have transforming and intrcellular signalling activity.  相似文献   

2.
Tumor angiogenesis is the uncontrolled growth of blood vessels in tumors,serving to supply nutrients and oxygen,and remove metabolic wastes.Kaposi's sarcoma (KS),a multifocal angioproliferative disorder characterized by spindle cell proliferation,neo-angiogenesis,inflammation,and edema,is associated with infection by Kaposi's sarcoma-associated herpesvirus (KSHV).Recent studies indicate that KSHV infection directly promotes angiogenesis and inflammation through an autocrine and paracrine mechanism by inducing pro-angiogenic and pro-inflammatory cytokines.Many of these cytokines are also expressed in KS lesions,implicating a direct role of KSI-IV in the pathogenesis of this malignancy.Several KSHV genes are involved in KSHV-induced angiogenesis.These studies have provided insights into the pathogenesis of KS,and identified potential therapeutic targets for this malignancy.  相似文献   

3.
We examine the conservation status of Africa's "Big Five": lion, leopard, buffalo, black and white rhinoceros and elephant, and the role of behavioral knowledge in their conservation. Efforts to conserve these flagship species consist of in situ conservation, captive breeding and reintroductions. With a few exceptions, we find limited evidence that knowledge of behavior informs conservation programs targeted at these species. For management in the wild, knowledge of infanticide and ranging can provide guidelines for realistic hunting quotas and corridors between protected areas, respectively. For ex situ and reintroduction programs, behavioral knowledge is chiefly focused on improved animal husbandry. Despite a formidable understanding of these species' behavior, the practicalities of using such knowledge may be diminished because exploitation of these species is so forceful and the bulk of efforts aimed at conserving these species (and indeed most other African species) are primarily in situ where behaviorally driven interventions are limited. Our comparative findings suggest that behavior has been of rather narrow use in the conservation of these flagship species [Current Zoology 60 (4): 486--499, 2014].  相似文献   

4.
The modulation and control of gecko's foot movements were studied electrophysiologically in order to design the motor control system of a gecko-mimic robot. In this study (1) the anatomy of the peripheral nerves controlling the gecko's foot movements was determined; (2) the relationship between the limb nerves of the gecko and its foot motor patterns was studied; (3) the afferent impulses of the nerves evoked by rubbing the gecko's toes and palm were recorded; (4) copying the natural patterns of movement of the gecko's foot (abduction, adduction, flexion, and revolution) and its limb nerve modulation and control mechanism, the nerves were stimulated under computer control, and the results recorded by CCD. Results suggest that gecko's foot movements can be successfully controlled by artificial electrical signals.  相似文献   

5.
The mechanical properties of the skull and the anti-shock characteristics of woodpecker's head were investigated by ex- periment and numerical simulation. We measured the micro-Young's modulus of the skull by nano-indentation method and calculated the macro-equivalent Young's modulus of the skull at different positions using homogenization theory. Based on the Computerized Tomography (CT) images of woodpecker head, we then built complete and symmetric finite element models of woodpecker's skull and its internal structure and performed modal analysis and stress spectrum analysis. The numerical results show that the application of pre-tension force to the hyoid bone can increase the natural frequency of woodpecker's head. The first natural frequency under the pre-tension force of 25 N reaches 57 Hz, which is increased by 21.3% from the non-pre-tension state and is more than twice the working frequency of woodpecker (20 Hz 25 Hz). On the application of impact force to the tip of beak for 0.6 ms, high magnitudes of stress component occur at around 100 Hz and 8,000 Hz, far away from both the working frequencies and the natural frequencies of woodpecker head. The large gaps among the natural, working and stress response frequencies enable the woodpecker to effectively protect its brain from the resonance injury.  相似文献   

6.
Di Qin  Chun Lu 《中国病毒学》2008,23(6):473-485
Kaposi sarcoma-associated herpesvirus (KSHV),also known as human herpesvirus 8 (HHV-8),is discovered in 1994 from Kaposi's sarcoma (KS) lesion of an acquired immunodeficiency syndrome (AIDS)patient.In addition to its association with KS,KSHV has also been implicated as the causative agent of two other AIDS-associated malignancies:primary effusion lymphoma (PEL) and multicentric Castleman's disease (MCD).KSHV is a complex DNA virus that not only has the ability to promote cellular growth and survival for tumor development,but also can provoke deregulated angiogenesis,inflammation,and modulate the patient's immune system in favor of tumor growth.As KSHV is a necessary but not sufficient etiological factor for KS,human immunodeficiency virus (HIV) is a very important cofactor.Here we review the basic information about the biology of KSHV,development of pathogenesis and interaction between KSHV and HIV.  相似文献   

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The ORFK8.1 of Kaposi's sarcoma associated-herpesvirus (KSHV) was expressed in a prokaryotic expression system. The expression of recombinant E.coli containing pQE-80L-orf K8.1 was induced by isopropyl-b-D-thiogalactopyranoside (IPTG). The fusion protein was purified by chromatyography. The expressed protein and its purified product were identified by sodium dodecyl sulfate-polyacrylamide gel eletrophoresis (SDS-PAGE). SDS-PAGE showed that a protein of 26 kDa was visualized as expected. A western blot assay was established to analyze the immunogenicity of purified recombinant 0RFK8.1 protein. The optimal condition of the recombinant ORFK8.1 ELISA assay was confirmed: the concentration of antigen was 5 ug/mL, the dilution of serum was 1:200. We used the ELISA method to investigate the recombinant ORF K8.1 protein's specificity, the data showed that the specificity of ORF K8.1 to detect KSHV was 100%. At the same time, 560 sera samples from Hubei province were detected by using ORFK8.1 ELISA to investigate KSHV seroprevalence in this region. The KSHV seroprevalence in Hubei province is shown to be 6.80%.  相似文献   

9.
A low-pathogenicity isolate of Listeria monocytogenes from cow's milk, as screened in mouse and chicken embryonated egg models, was examined for virulence-related phenotypic traits. Corresponding virulence genes (iap, prfA, picA, hly, mpl, actA, plcB, InlA and lnlB) were compared with L. monocytogenes reference strains 10403S and EGD to elucidate the possible molecular mechanisms of low virulence. Although L. monocytogenes H4 exhibited similar patterns to strain 10403S in terms of hemolytic activity, in vitro growth and invasiveness and even had higher adhesiveness, faster intracellular growth and higher phospholipase activity in vitro, it was substantially less virulent than the strain 10403S in mouse and chicken embryo models (50% lethal dose: 10^8.14 VS. 10^5.49 and 10^6.73 VS. 10^1.9, respectively). The genes prfA, picA and mpl were homologous among L. monocytogenes strains H4, 10403S and EGD (〉98%). Genes iap, hly, plcB, lnlA and lnlB of L. monocytogenes 10403S had higher homology to those of strain EGD (〉98%) than isolate H4. The homology of the gene hly between strain 10403S and isolate H4 was 96.9% at the nucleotide level, but 98.7% at the amino acid level. The actA gene of isolate H4 had deletions of 105 nucleotides corresponding to 35 amino acid deletions falling within the proline-rich region. Taken together, this study presents some clues as to reduced virulence to mice and chicken embryos of the isolate H4 probably as a result of deletion mutations of actA.  相似文献   

10.
China's Free ART Program was initiated in 2002 as an emergency response to save and improve the lives of AIDS patients living mainly in impoverished rural regions of central China. With little experience in HIV/AIDS treatment and care and resource limitations, China's efforts to provide widespread access to free antiretroviral therapy has been a process fraught with difficulty. However, the Free ART Program is progressing from an emergency response to a standardized treatment and care system. The development of national guidelines, training programs, a laboratory support network, a national patient database, programs for special populations such as children and patients living with coinfections, and operational research has improved the scope and quality of the free treatment program. As of June 30, 2005, a total of 19,456 patients in 28 provinces, autonomous regions, and special municipalities had received free ART. Challenges stemming from the nature of China's health system and patient population persist, but with strong government support and a diverse set of resources, China has the capacity to overcome these challenges and to provide nationwide access to high quality treatment and care.  相似文献   

11.
《Cell research》2005,15(8):F0005-F0006
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12.
《Cell research》2005,15(7):556-557
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正I am writing to apologize for our negligence and in our paper[Xin HUANG,Tao PAN,Demin HAN,Liang ZHANG,Yinxu HOU,Lei YU,Heming ZHANG,Baowei ZHANG.2012.A New Species of the Genus Protobothrops(Squamata:Viperidae:Crotalinae)from the Dabie Mountains,Anhui,China.Asian Herpetol Res,3(3):213-218],in which we failed to report some key information on holotype.Here we provide  相似文献   

15.
This is the special issue devoted to bioinformatics research in Singapore. Bioinformatics research in Singapore started largely in 1996 when the Bioinformatics Center, National University of Singapore, was formed. With the government's efforts to turn Singapore into a powerhouse of biomedical research, the Genome Institute of Singapore and the Bioinformatics Institute of Singapore have been established since 2000. Recently, a bioinformatics research center was also formed in the Nanyang Technological University. Currently, there are a large number of bioinformatics research teams in each of these institutions.  相似文献   

16.
The Sandfish's Skin: Morphology, Chemistry and Reconstruction   总被引:1,自引:0,他引:1  
The sandfish is a lizard having the remarkable ability to move in desert sand in a swimming-like fashion. The most outstanding adaptations to this mode of life are the low friction behaviour and the extensive abrasion resistance of the sandfish skin against sand, outperforming even steel. We investigated the topography, the composition and the mechanical properties of sandfish scales. These consist of glycosylated keratins with high amount of sulphur but no hard inorganic material, such as silicates or lime. Remarkably, atomic force microscopy shows an almost complete absence of attractive forces between the scale surface and a silicon tip, suggesting that this is responsible for the unusual tribological properties. The unusual glycosylation of the keratins was found to be absolutely necessary for the described phenomenon. The scales were dissolved and reconstituted on a polymer surface resulting in properties similar to the original scale. Thus, we provide a pathway towards exploitation of the reconstituted scale material for future engineering applications.  相似文献   

17.
By the end of 2005, the estimated number of HIV infected people in China was 650,000. The seriousness of the epidemic calls for effective control measures to tackle the problems in order to avoid the tragedy in Africa from happening in China. "Prevention First" is the cornerstone of the country's health policy. On 2003 World AIDS Day, Premier Jiabao Wen announced a new national AIDS control policy, "Four Frees and One Care". This policy clearly shows that the Chinese government has once again taken full responsibility to solve public health problems and has profound impact far beyond the AIDS field. In early 2006, the central government put scientific and technology innovation as a national priority and set the target to build an innovative China by year 2020. Since then, the government has been increasing investment in science and technology with major emphasis on both infectious diseases control and new drug research and development. For the first time, development of 100 new drugs and control of major infectious diseases (AIDS, HBV, TB and other emerging infectious diseases) have been selected as national key scientific projects. China's best minds in related fields will be pooled to work together in order to remove the technical barriers blocking efficient control of the major infectious disease in China. Knowledge on molecular epidemiology, immunology, pathogenesis, HAART, as well as HIVDR strains will certainly provide urgently needed scientific information for China's AIDS control program. Only evidence-based strategy from good research will provide long-term effective control of AIDS.  相似文献   

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Wnts comprise a large family of proteins that have shown to be part of a signaling cascade that regulates several aspects of develop- ment including organogenesis, mid brain development as welt as stem cell proliferation. Wnt signaling pathway plays different roles in the development of neuronal circuits and also in the adult brain, where it regulates synaptic transmission and plasticity. It has been also implicated in various diseases including cancer and neurodegenerative diseases, reflecting its relevance in fundamental biological pro- cesses. This review summarizes the progress about Wnts function in mature nervous system with a focus on Alzheimer's disease (AD). We discuss the prospects of modulating canonical and non-canonical Wnt signaling as a strategy for neuroprotection. This will include the potential of Wnts to: (i) act as potent regulators of hippocampai synapses and impact in learning and memory; (ii) regulate adult neurogenesis; and finally (iii) control AD pathogenesis.  相似文献   

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