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1.
Tissue samples from 160 European hedgehogs, Erinaceus europaeus, representing eight small populations from a highly fragmented landscape in Oxfordshire, UK, were screened for polymorphism at six microsatellite loci. Permutation analysis of allelic compositions revealed no evidence for linkage disequilibrium among loci. Genotype proportions within populations and at five loci did not differ from those expected at Hardy-Weinberg equilibrium. However, significant heterozygote deficit and amplification failure of several samples necessitated removal of one locus from the analysis. Mean observed heterozygosity was 0.70. Average RhoST was 0.079 and differed significantly from zero, suggesting restricted gene flow among local populations. Pairwise Nm values and geographical distance were not correlated, indicating that factors other than distance affected dispersal.  相似文献   

2.
The distribution of the noradrenaline (NA)- and dopamine (DA)-containing neuronal structures in the central nervous system of the hedgehog (Erinaceus europaeus), a phylogenetically old mammalian species, was immunocytochemically studied employing antibodies directed against the catecholamines (CA) themselves. Groups of DA cell bodies observed in this study were similar to those present in other species but the distributional map of the NA-containing cell bodies exhibited some peculiarities. Prominent among them were the absence of the A3 group and the paucity of CA cells in the A2 group. DA neurons in the hypothalamus, apart from the densely populated paraventricular and arcuate nuclei, were fewer and less widely distributed than in other species. In the hedgehog mesencepha- Ion, in contrast to what has been described in other species, the major DA cell group was present in the ventral tegmental area. CA immunoreactive fibers were widely distributed in the CNS of the hedgehog. However, similarly to what has been observed in other species, terminal fields of DA neurons were much more restricted when compared to those of the NA neurons. The neocortical DA projection system of the hedgehog appeared less developed but organized similar to that of the rat, and even less developed than that of the primates. The lack of profound regional and laminar variations in the density of cortical NA fibers in the hedgehog enhances the suggestion that the elaboration and differentiation of the NA cortical system parallels the phylogenetic development of the cortex. In the brainstem, interspecies differences in the distribution of the CA fibers were found to concern primarily some hypothalamic areas (medial preoptic area, suprachiasmatic nucleus, arcuate nucleus). Such differences in the thalamus concerned the NA innervation and they were notably present in the visual thalamic nuclei (dorsal lateral geniculate nucleus, lateral posterior thalamic nucleus). In the spinal cord, which was found to receive fewer CA afferents than those found in other species, the density of the DA fibers was much lower than that of the NA axons. In addition to the CNS areas that have been described in other species to receive catecholaminergic innervation, the present study showed that both types of catecholaminergic fibers are distributed in the choroid plexus and along the ventricular wall of the brain ventricles and the central canal of the hedgehog.  相似文献   

3.
In Drosophila, it has been shown that protein kinase A and hedgehog have antagonistic actions during the formation of imaginal disks. In vertebrate skin, sonic hedgehog is expressed specifically in the feather bud epithelia. using an in vitro explant culture model we showed that dibutyryl cAMP, a protein kinase A (PKA) activator, suppresses the expression of Sonic hedgehog, (Shh) and continuous feather growth. The results suggest that Shh and PKA also have antagonistic action during vertebrate skin morphogenesis.  相似文献   

4.
The cyclin-dependent kinase, proliferating cell nuclear antigen, and stress-activated protein kinase/c-jun NH2 terminal kinase inhibitor p21WAF1/CIP1 can induce G1 arrest, and its expression coincides with the cessation of replication in many systems. We examined expression of p21 during the early stages of carbon tetrachloride intoxication in the mouse liver and observed a dramatic increase in p21 RNA levels between 4 and 8 h after administration. p21 expression, visualized by in situ hybridization, is induced in pericentral hepatocytes before carbon tetrachloride-induced necrosis. Examination of c-fos and c-myc expression patterns confirm that these immediate-early genes are induced in similar regions of the mouse liver. p21 induction is not dependent on p53; we observed similar levels and localization of p21 in wild-type and p53 null animals. Immunohistochemical localization of p21 and CCAAT/enhancer-binding protein expression shows that p21 protein accumulation is limited to a subset of CCAAT/enhancer-binding protein-positive hepatocytes. A second peak of periportal and intermediate zone-specific p21 gene expression, appearing 1-2 days after injection, is also p53 independent and may represent cell cycle checkpoints or postmitotic growth arrest. Sporadic p21 expression was also detected in pairs of hepatocytes distributed throughout the liver acini in healthy animals. Together, these data suggest several roles for p21 in the liver in response to toxicity, regeneration, and growth inhibition.  相似文献   

5.
Recent research has found that family caregivers do not discuss their caregiving in terms of tasks but instead describe their care as shaped by concerns, commitments and goals. The purpose of this paper is to challenge the ways in which nurses approach the family caregiving process and to explore possibilities for evolving nursing knowledge by questioning existing practice in the light of developing insight into the ways in which being a family caregiver is meaningful. A critique of the philosophical orientations of rationalism and empiricism provides a platform to discuss the merits of a Heideggerian phenomenological approach in assisting nurses to better understand family caring experience. Such critique serves to support the notion of displacing the traditional scientific view as the prime means of disclosing truth, acknowledging alternative ways of knowing.  相似文献   

6.
Cardiac dysrhythmias in septic patients often reflect hypovolaemia, hypokalaemia or endocarditis as cardiac manifestation of the infection, but may be indicative for underlying cardiac pathology previously undiagnosed. We report on the case of a patient with severe peritonitis, on whom transoesophageal echocardiography (TEE) had been performed intraoperatively due to progressive circulatory instability. TEE revealed first diagnosis of asymmetric hypertrophic cardiomyopathy, which complicated the features of septic syndrome. Further perioperative treatment to support the circulation was successfully adjusted on the grounds of this diagnosis.  相似文献   

7.
A sample of 84 smokers attending health promotion clinics in a primary care setting completed questionnaires that assessed the main constructs of the theory of planned behavior, perceived susceptibility, and past cessation attempts. Regression analyses revealed that intention to quit smoking was primarily predicted by perceived behavioral control and perceived susceptibility. At 6-month follow-up, the making of a quit attempt was predicted by intention and the number of previous quit attempts, whereas the length of the quit attempt was predicted solely by the length of the longest recent quit attempt. The results suggest that interventions should focus on perceptions of susceptibility and control to increase smokers' motivation to quit. However, further work is required to identify the social cognitive variables that ensure that initial quit attempts are translated into longer term abstinence.  相似文献   

8.
Antistasin is a Factor Xa inhibitor that is present in the salivary glands of the Mexican leech Haementeria officinalis. The antistasin protein consists of 119 amino acids, of which residues 1-55 (domain I) are 56% similar to residues 56-110 (domain II). Of the nine C-terminal amino acids (residues 111-119; domain III), four are positively charged. The reactive site for Factor Xa is located in domain I. In this study we assessed the role of separate domains and of individual amino acids in the reactive site for the inhibition of Factor Xa. A series of mutants was constructed and expressed in Chinese hamster ovary (CHO) cells. In vitro chromogenic assays for Factor Xa show that domain I is sufficient for inhibition of Factor Xa. Domains II and III neither contain any intrinsic Factor Xa inhibitory activity, nor contribute to the activity of domain I. Furthermore, domain II does not become a Factor Xa inhibitor by partially adaptating its sequence towards that of the reactive site in domain I. Mutation of the cysteine at position 33 is not crucial for Factor Xa inhibition, suggesting a relatively rigid reactive site loop structure.  相似文献   

9.
In order first to overcome the difficulties in understanding the increasing amount of information available regarding the mammalian somatosensory thalamus, and then to correlate the findings among different species and integrate them into a general concept of thalamic organization, the present study investigated the spinothalamic and medial lemniscal projections in Madagascan hedgehog tenrecs (Echinops telfairi and Setifer setosus). Tracer substances were injected into the dorsal column nuclei and into spinal segments at various levels; additional injections were made into the inferior colliculus. The ascending somesthetic projections were to predominantly contralateral posterolateral target areas, and were almost mirror-like on both sides to intralaminar and medial thalamic nuclei. The densest and most extensive projections, originating mainly from the high cervical spinal cord and the dorsal column nuclei, reached the posterolateral thalamus caudal to the lateral geniculate nucleus. This region was difficult to subdivide cytoarchitecturally; nevertheless, on the basis of its labeling pattern, several subdivisions could be described and preliminary named. Some of them compared tentatively with the internal portion of the medial geniculate nucleus (GM) and the ventral posterior nuclear complex (VPC) in more differentiated mammals. The most prominent subdivision, however, located subjacent to the lateral surface of the brainstem, was shown to receive additional fibers from the inferior colliculus. This region might be considered a further subdivision of GM, VPC, a perigeniculate area, and/or a region of its own not comparable at present, with thalamic regions in other mammals. On the other hand, it may also be a remnant of the hypothetical, diffuse multimodal region from which GM and VPC have possibly evolved.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

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The genes engrailed (en), hedgehog (hh), wingless (wg) and decapentaplegic (dpp) have been shown to play vital organising roles in the development and differentiation of thoracic imaginal discs. We have analysed the roles of these genes in organising the development and differentiation of the genital discs, which are bilaterally symmetrical and possess different primordia, namely, the male and female genital primordia and an anal primordium. Our results suggest that the organising activity of en in genital discs programs the normal development and differentiation of the genital disc by regulating the expression of hh. Hh in turn induces wg and dpp, the genes whose products act as secondary signalling molecules. Moreover, the complementary patterns of wg and dpp expression are essential for the bilateral symmetry and are maintained by mutual repression.  相似文献   

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Ethnic and generation differences in the frequency and types of ethnic socialization messages that 524 eleventh-grade adolescents from Mexican, Chinese, and European backgrounds received from their parents were examined. Results indicated that adolescents from both Mexican and Chinese backgrounds reported more cultural socialization and preparation for bias messages than their peers from European backgrounds. Chinese adolescents reported more promotion of mistrust messages than their peers with European backgrounds. Moreover, promotion of mistrust messages negatively predicted academic achievement, whereas positive cultural socialization messages accounted for the higher levels of motivation among adolescents from Chinese and Mexican backgrounds as compared with their equally achieving peers from European backgrounds. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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In 3 prior meta-analyses, the relationship between the Big Five factors of personality and job criteria was investigated. However, these meta-analyses showed different findings. Furthermore, these reviews included studies carried out only in the United States and Canada. This study reports meta-analytic research on the same topic but with studies conducted in the European Community, which were not included in the prior reviews. The results indicate that Conscientiousness and Emotional Stability are valid predictors across job criteria and occupational groups. The remaining factors are valid only for some criteria and for some occupational groups. Extraversion was a predictor for 2 occupations, and Openness and Agreeableness were valid predictors of training proficiency. These findings are consistent with M. R. Barrick and M. K. Mount (see record 1991-22928-001) and L. M. Hough et al (see record 1991-06268-001). Implications of the results for future research and the practice of personnel selection are suggested. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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Describes J. P. Hall's experience at the First European Congress of Psychology and ways in which this experience altered Hall's perceptions of psychology. It is concluded that European psychology is strong and in some significant ways less conflicted than American psychology. A more international approach to the discipline is needed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

20.
Cyclosporine (CsA) administration to patients with recurrent focal segmental glomerulosclerosis (FSGS) after transplantation results in remission of proteinuria. We have shown that sera from patients with recurrent FSGS can increase the glomerular albumin permeability (Palbumin) and that increase in glomerular cAMP levels can alter the permeability characteristics of glomeruli in vitro. The purpose of this study was to determine if the increased glomerular levels of cAMP were related to the protective effects of CsA on an increase in Palbumin by FSGS sera. Glomeruli from Sprague-Dawley rats following intraperitoneal administration of CsA (25 mg/kg/day), cremophore (25 mg/kg/day), or saline for 5 days were incubated with 1:50 dilution of serum from three FSGS patients or with pooled normal human serum prior to calculation of Palbumin. Glomerular cAMP was measured by radioimmunoassay. Glomerular ultrastructural changes were assessed by transmission electron microscopy (TEM). Serum from three FSGS patients markedly increased Palbumin of glomeruli from saline or cremophore treated rats (saline, 0.68+/-0.08; 0.72+/-0.07; 0.70+/-0.07; and cremophore, 0.79+/-0.05; 0.81+/-0.02; 0.79+/-0.01; n=25 glomeruli in each group). In contrast Palbumin of glomeruli from CsA treated rats was not increased by any of the three FSGS sera tested (0.03+/-0.02; 0.04+/-0.05; 0.02+/-0.07, n=25 glomeruli in each group). Glomerular cAMP (pmol/mg of protein) increased 5 fold in CsA treated rats (328+/-26; 5 rats) compared with cremophore or saline treated rats (87+/-24 and 65+/-23, P<0.01; 5 rats in each group). The glomerular basement membrane appeared to be thickened and the lamina densa had an irregular appearance after treatment with CsA. No ultrastructural changes of glomerular epithelial or endothelial cells were evident. We conclude that CsA may have a direct protective effect on the glomerular filtration barrier in FSGS. We postulate that increased levels of glomerular cAMP by CsA may play an important role in protecting the glomerular Palbumin effect of the FSGS factor and may contribute to remission of proteinuria in FSGS patients.  相似文献   

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