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Zhengzhi Li

Publications and source records attributed to Zhengzhi Li.

7 recordsLinked to original sources
PubMed2006

Community surveys and risk factor analysis of human alveolar and cystic echinococcosis in Ningxia Hui Autonomous Region, China.

OBJECTIVE: To determine the true community prevalence of human cystic (CE) and alveolar (AE) echinococcosis (hydatid disease) in a highly endemic region in Ningxia Hui, China, by detecting asymptomatic cases. METHODS: Using hospital records and "AE-risk" landscape patterns we selected study communities predicted to be at risk of human echinococcosis in Guyuan, Longde and Xiji counties. We conducted community surveys of 4773 individuals from 26 villages in 2002 and 2003 using questionnaire analysis, ultrasound examination and serology. FINDINGS: Ultrasound and serology showed a range of prevalences for AE (0-8.1%; mean 2%) and CE (0-7.4%; mean 1.6%), with the highest prevalence in Xiji (2% for CE, 2.5% for AE). There were significant differences in the prevalence of CE, AE and total echinococcosis between the three counties and villages (with multiple degrees of freedom). While hospital records showed 96% of echinococcosis cases attributable to CE, our survey showed a higher prevalence of human AE (56%) compared to CE (44%). Questionnaire analysis revealed that key risk factors for infection were age and dog ownership for both CE and AE, and Hui ethnicity and being female for AE. Drinking well-water decreased the risk for both AE and CE. CONCLUSION: Echinococcosis continues to be a severe public health problem in this part of China because of unhygienic practices/habits and poor knowledge among the communities regarding this disease.

Adolescent↗
PubMed2006

Unique family clustering of human echinococcosis cases in a chinese community.

We have identified a significant focus and unusual clustering of human cases of cystic echinococcosis (CE) and alveolar echinococcosis (AE) in the village of Nanwan, Xiji County, Ningxia Hui Autonomous Region, in one of the most highly endemic areas for both diseases in China. The village, a Chinese Hui Islamic community, is composed of 167 members of four extended families. A total of 28 people died (12 of echinococcosis) since the village was first settled in the 1950s. Despite similar life patterns, the number of AE and CE cases occurring in each family was different. Overall, the prevalences of AE and CE were 9% (20 cases) and 5.9% (13 cases), with a combined prevalence of 14.9%. In contrast to CE, a comparison of the prevalence of AE indicated significant differences between the four family clusters. Although suggestive that host genotype might play a role in susceptibility to AE, this hypothesis requires further investigation.

Adolescent↗
PubMed2006

[Three-dimensional spatial distribution patterns of Monochamus alternatus and its natural enemy Dastarcus helophoroides].

In 2003 to approximately 2005, the Monochamus alternatus-infected Pinus thunbergii, P. massoniana and P. elliotii in pure and mixed forests were selected as attractants and dissected with one meter section manner, and five aggregation indices were used to analyze the spatial distribution patterns of M. alternatus and its natural enemy Dastarcus helophoroides. The results showed that M. alternatus and D. helophoroides had the horizontal distribution indices of diffused coefficient C > 1, diffused index I delta > 1, Kuno index C(A) > 0, clump intensity index I > 1, and swarm index Iw > 1 in the two stands, suggesting their aggregated horizontal distribution patterns, and except D. helophoroides on the P. massoniana in mixed forest appeared assemble vertical distribution, these two insects all had an even vertical distribution, with their C < 1, I delta < 1, C(A) < 0, Iw < 1, and I < 0. The spatial distribution patterns of M. alternatus and D. helophoroides were consistent, and the latter was spatially following the former.

Animals↗
PubMed2005

Novel collectin/C1q receptor mediates mast cell activation and innate immunity.

Mast cells play a critical role in innate immunity, allergy, and autoimmune diseases. The receptor/ligand interactions that mediate mast cell activation are poorly defined. The alpha2beta1 integrin, a receptor for collagens, laminins, decorin, E-cadherin, matrix metalloproteinase-1 (MMP-1), endorepellin, and several viruses, has been implicated in normal developmental, inflammatory, and oncogenic processes. We recently reported that alpha2 integrin subunit-deficient mice exhibited markedly diminished neutrophil and IL-6 responses during Listeria monocytogenes- and zymosan-induced peritonitis. Peritoneal mast cells require alpha2beta1 integrin expression for activation in response to pathogens, yet the ligand and molecular mechanisms by which the alpha2beta1 integrin induces activation and cytokine secretion remain unknown. We now report that the alpha2beta1 integrin is a novel receptor for multiple collectins and the C1q complement protein. We demonstrate that the alpha2beta1 integrin provides a costimulatory function required for mast cell activation and cytokine secretion. This finding suggests that the alpha2beta1 integrin is not only important for innate immunity but may serve as a critical target for the regulation of autoimmune/allergic disorders.

Animals↗
PubMed2003

Mast cell-mediated inflammatory responses require the alpha 2 beta 1 integrin.

Although the alpha 2 beta 1 integrin is widely expressed and has been extensively studied, it has not been previously implicated in mast cell biology. We observed that alpha 2 integrin subunit-deficient mice exhibited markedly diminished neutrophil and interleukin-6 responses during Listeria monocytogenes- and zymosan-induced peritonitis. Since exudative neutrophils of wild-type mice expressed little alpha 2 beta 1 integrin, it seemed unlikely that this integrin mediated neutrophil migration directly. Here, we demonstrate constitutive alpha 2 beta 1 integrin expression on peritoneal mast cells. Although alpha 2-null mice contain normal numbers of peritoneal mast cells, these alpha 2-null cells do not support in vivo mast cell-dependent inflammatory responses. We conclude that alpha 2 beta 1 integrin provides a costimulatory function required for mast cell activation and cytokine production in response to infection.

Animals↗
PubMed2003

The contributions of the alpha 2 beta 1 integrin to vascular thrombosis in vivo.

The alpha 2 beta 1 integrin serves as a receptor for collagens, laminin, and several other nonmatrix ligands. Many studies have suggested that the alpha 2 beta 1 integrin is a critical mediator of platelet adhesion to collagen within the vessel wall after vascular injury and that the interactions of the platelet alpha 2 beta 1 integrin with subendothelial collagen after vascular injury are required for proper hemostasis. We have used the alpha 2 beta 1 integrin-deficient mouse to evaluate the contributions of the alpha 2 beta 1 integrin in 2 in vivo models of thrombosis. Studies using a model of endothelial injury to the carotid artery reveal that the alpha 2 beta 1 integrin plays a critical role in vascular thrombosis at the blood-vessel wall interface under flow conditions. In contrast, the alpha 2 beta 1 integrin is not required for the formation of thrombi and pulmonary emboli following intravascular injection of collagen. Our results are the first to document a critical in vivo role for the alpha 2 beta 1 integrin in thrombus formation at the vessel wall under conditions of shear following vascular injury.

Animals↗