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991.
992.
Dyschondrosteosis (DCO) and hypochondroplasia (HCH) are common skeletal dysplasias characterized by disproportionate short stature. The diagnosis of these conditions might be difficult to establish especially in early childhood. Point mutations and deletions of the short stature homeobox containing gene (SHOX) are detected in DCO and idiopathic short stature with some rhizomelic body disproportion, whereas mutations in the fibroblast growth factor receptor 3 (FGFR3) gene are found in 40-70% of HCH cases. In this study, we performed mutational analysis of the coding region of the SHOX gene in five DCO and 18 HCH patients, all of whom tested negative for the known HCH-associated FGFR3 mutations. The polymorphic CA-repeat analysis, direct sequencing and Southern blotting were used for detection of deletions and point mutations. The auxological and radiological phenotype of these patients was carefully determined. Three novel mutations in DCO patients were found: (1) a deletion of one base (de1272G) (according to GenBank accession nos. Y11536, Y11535), resulting in a premature stop codon at position 75 of the amino acid sequence; (2) the transversion C485G resulting in the substitution Leu132Val; and (3) the transversion G549T causing an Arg153Leu substitution. These substitutions segregate with the DCO phenotype and affect evolutionarily conserved homeodomain residues, based on a comparison of homeobox containing proteins in 13 species. Moreover, these changes were not found in 80 unrelated, unaffected individuals. This strongly suggests that these mutations are pathogenic. The phenotype of our patients with DCO and HCH varied from mild to severe shortness and body disproportion. These results further support clinical and genetic heterogeneity of dyschondrosteosis and hypochondroplasia.  相似文献   
993.
We describe behavioral sequences and daily activities of pre-ovipositing and ovipositing females of Cephalonomia stephanoderis (Hymenoptera: Bethylidae), an ectoparasitoid of the coffee berry borer, Hypothenemus hampei (Coleoptera: Scolytidae). Noticeable behavioral differences among preovipositing and ovipositing females include host examination, host stinging—probing, host feeding, and the oviposition per se. The female of C. stephanoderis feeds primarily on host eggs, but pupae are also exploited, mainly by pre-ovipositing females. After the onset of the oviposition period, C. stephanoderis examines the pupae repeatedly, stings them at frequent intervals, and spends more time feeding than during the pre-oviposition period. Host paralysis is linked both to host feeding and oviposition. It induces irreversible developmental arrest, which presumably allows preservation of the host until subsequent utilization, and contributes to successful offspring development, particularly by reducing host motility. Oviposition consists in a host selection process, a prolonged period of preparation of the potential host, and the egg-laying phase itself. Under our experimental conditions, pre-ovipositing and ovipositing females are active 17% and 36% of the day, respectively. Host handling time averages 6% and 23% in pre-ovipositing and ovipositing females, respectively. All coffee berry borer developmental stages are exploited by C. stephanoderis females, either for host feeding and/or oviposition activities. Such flexible behavior is advantageous given that host availability is limited inside the coffee berries.  相似文献   
994.
We consider a simple stochastic model for the dynamics of mixed-species waterfowl aggregations and describe two methods for assessing the fit of this model to field data. The model does not incorporate species-specific behavior. It assumes that all birds act independently and incorrectly predicts an exponential distribution for inter-event times. We reject this model, show that 29% of the birds move in groups of two or more birds, and demonstrate that the distribution of inter-event times between the movements of groups of birds is exponential. We find no difference in movement rates or group sizes between seasons, and no difference between groups arriving into or departing from the observed aggregations. An analysis of group composition suggests that species at low abundance behave differently than species at high abundance: birds with few conspecifics are more likely to move in mixed-species groups than birds with many conspecifics. We suggest that simple stochastic models provide a useful way to explore the dynamics of animal behavior.  相似文献   
995.
996.
Interleukin-1 (IL-1) has been implicated in the regulation of the expression of various matrix metalloproteinases (MMPs) in many mesenchymal cell types, but its role in liver myofibroblasts (MFs) has not been elucidated. A myofibroblast-like cell line, MG2, was derived from an isolate of rat hepatic stellate cells (HSCs). These cells expressed desmin, vimentin, smooth muscle -actin, and fibulin-2. Using a recombinant IL-1 at 5 ng/ml, it was shown that IL-1 would upregulate, while IL-1Ra, an IL-1 receptor antagonist, would down-regulate the expression of IL-1 mRNA in MG2 cells, indicating the presence of an autostimulatory loop of IL-1 in these cells. Besides, a paracrine source of IL-1 may be produced from Kupffer cells, as we showed primarily cultured Kupffer cells responded much more remarkably than MG2 cells to lipopolysaccharide stimuli to produce both IL-1 and IL-1. Recombinant IL-1 upregulated the expression of both MMP-9 and -13, and the induction of MMP-13 but not MMP-9 could be inhibited by SB203580, an inhibitor of p38. Similarly, in primarily cultured human liver MFs, upregulation of MMP-1 by IL-1 was also shown to be inhibited by SB203580. All of these data suggested that, during liver inflammation, IL-1 produced by an autocrine model from MFs or by a paracrine model from Kupffer cells might play a crucial role in the remodeling of liver fibrosis through an either p38-dependent or p38-independent pathway to regulate the expression of various MMPs by liver MFs.  相似文献   
997.

Background  

There is an ongoing discussion about age limits for deep brain stimulation (DBS). Current indications for DBS are tremor-dominant disorders, Parkinson's disease, and dystonia. Electrode implantation for DBS with analgesia and sedation makes surgery more comfortable, especially for elderly patients. However, the value of DBS in terms of benefit-risk ratio in this patient population is still uncertain.  相似文献   
998.
Experimental measurements on a cm-scale replica structure of a gecko foot-hair where magnets are used in place of (the usual) van der Waals force are reported. We conduct naked-eye experiments and investigate the mechanical properties of such hair structure and shapes that constitute it. Links between shapes and mechanical properties (functions) useful in geckos for clinging onto walls and adhering to rough surfaces are explained in terms of energy efficiency.  相似文献   
999.
Pulmonary involvement is common in sarcoidosis, an immune-mediated inflammatory disorder that is characterized by non-caseating granulomas in tissue. Sarcoid patients with advanced pulmonary disease, especially end-stage pulmonary fibrosis, risk developing pulmonary hypertension (World Health Organization group III pulmonary hypertension secondary to hypoxic lung disease). Increased levels of endothelin (ET)-1 in plasma and bronchoalveolar lavage of some sarcoid patients suggest that ET-1 may be driving pulmonary fibrosis and sarcoidosis-associated pulmonary hypertension. Although a relationship between raised levels of ET-1 and clinical phenotype is yet to be identified, early evidence from studies of ET-1 blockade with drugs such as bosentan is encouraging. Such therapy possibly could be combined with standard anti-inflammatory agents to improve outcome.  相似文献   
1000.
Achievement of transposon mediated germline transgenesis in a basal chordate, Ciona intestinalis, is discussed. A Tc1/mariner superfamily transposon, Minos, has excision and transposition activities in Ciona. Minos enables the creation of stable transgenic lines, enhancer detection, and insertional mutagenesis.  相似文献   
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