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排序方式: 共有641条查询结果,搜索用时 15 毫秒
1.
2.
The role of function in the formation of the skull 总被引:1,自引:0,他引:1
G H Schumacher D Ivánkievicz J Fangh?nel 《Acta morphologica Academiae Scientiarum Hungaricae》1979,27(1-2):53-56
Partial resection of the mandible, resection of the chewing muscles, amputation of extremities and ligature of the common carotid artery were performed in animals different in chewing type (dogs, sheep, rabbits and rats). These studies revealed a close relation between shape and function. It was shown that changes in function have a decisive effect on the development and shaping of the skull bones and musculature. 相似文献
3.
Immunohistochemical identification of tubular segments in percutaneous renal biopsies 总被引:1,自引:0,他引:1
Summary To identify the renal cortical tubular segments involved in tubulo-interstitial disease in formalin-fixed, paraffin-embedded percutaneous kidney biopsies, we developed multiple immunolabeling protocols using segment-specific tubular markers. The present study of biopsies from patients with minimal change or thin basement membrane nephropathy provides a baseline for interpretation of histopathology. Proximal tubules were stained either by the PAS reaction or by the biotinylated Phaseolus vulgaris erythroagglutinin (PHA-E)-streptavidin-gold-silver system (brush borders black). The anti-Tamm-Horsfall (THP) antibody-immunoperoxidase (aminoethylcarbazole, AEC-IPO), and anti-epidermal cytokeratins (ECK) antibodies-immunoalkaline-Fast Blue BB methods marked the distal straight tubules and the cortical collecting system red-brown and blue, respectively. When these immunolabelings were combined, the coapplication of AEC-PO-labeled peanut agglutinin (PNA) or anti-epithelial membrane antigen antibody-AEC-IPO technique (both are markers for distal nephron) visualized the apical membranes of distal convoluted tubules. In the protocol PHA-E + PNA + THP + ECK, the tubular basement membranes were outlined by the anti-laminin antibody-AEC-IPO staining, carried out simultaneously. The protocol PNA + THP + ECK + PAS was found to be a quite appropriate multiple immunolabeling method for the tubules, and is recommended for use as a tool in the study of tubulo-interstitial diseases.Abbreviations PAS
periodic acid-Schiff reaction
- PHAE
Phaseolus vulgaris erythroagglutinin
- PNA
Peanut agglutinin
- EMA
epithelial membrane antigen
- THP
Tamm-Horsfall glycoprotein
- ECK
epidermal cytokeratins
- PO
peroxidase
- Biot-PHA-E
biotinylated PHA-E
- APAAP
complexes of alkaline phosphatase and mouse monoclonal anti-alkaline phosphatase
- SWARI
swine anti-rabbit immunoglobulins
- FCS
fetal calf serum
- TBS
Tris-buffered saline
- AEC
aminoethylcarbazole
- DAB
diaminobenzidine
- FBBB
Fast Blue BB
- IA
immunoalkaline
- GL
glomerulus
- PT
proximal tubule
- DST
distal straight tubule
- DCT
distal convoluted tubule
- CCS
cortical collecting system
- CT
connecting tubule
- CD
collecting duct 相似文献
4.
Iván Ortega Blake 《Journal of theoretical biology》1980,83(4):595-621
The solution to the a.c. cable equations for a leaky non-inductive coaxial cable is presented. It is shown that the exact solution can be expressed in terms of a simple Ohm's law formulation modified by multiplicative factors. A numerical analysis of these factors shows that the formulation reduces to a simple Ohm's law for the case of infinite impedance terminations, if the voltage is recorded at a distance 0·421/λ from the centre of a midpoint current injection, 1 is the half-length of the cell and A the space constant. The same result applies to the case of external current injection if the voltage is recorded at a distance of 0·581/λ from the centre of the cell segment of length 21. This thus allows an easy and accurate computation of the membrane resistance and capacitance. It is also shown that the accuracy obtained in these computations can be estimated quantitatively. The actual values of the accuracy obtained in a.c. studies of Nitella translucens are presented. 相似文献
5.
The inbred strains GRS/A and LIS/A carry the haplotypeH-2
dx
, which had earlier been shown to have theK
d
,I
f
,S
f
, andG
f
alleles and a previously unknownD region allele,D
dx
. We show here that theD
dx
allele determines a new private specificity, H-2.63, is H-2.28 negative, and determines at least one public specificity of the H-2.1 family. It is thus a second example (afterD
k
) of a H-2.1-positive H-2.28-negativeD region allele. Capping experiments show that the Ddx product comprises two molecules: H-2Ddx bearing the private specificity H-2.63, and H-2Ldx, which is H-2.63-negative but reacts with sera against the H-2.1 family of specificities. SDS gel electrophoresis of detergent-solubilized immunoprecipitated Ddx products shows that the H-2Ldx antigen has a molecular weight of approximately 45,000 daltons and is associated with a smaller polypeptide (mol. wt. 12,000). 相似文献
6.
Serological and capping experiments show that the strain B10.D2 (M504) carrying the mutant haplotypeH-2
dm1
has two molecules in the products of theD region: H-2Ddm1 and H-2Ldm1 which are detectable by anti-H-2.4 and by anti-H-2.28 sera, respectively. Both these molecules differ serologically from the H-2Dd and H-2Ld molecules of the original (nonmutant) strain B10.D2. A third molecule, different from H-2D and H-2L, was detected inH-2
d
,H-2
dm2
but not inH-2
dm1
products. 相似文献
7.
8.
Altered ATP Hydrolysis Induced by Pentylenetetrazol Kindling in Rat Brain Synaptosomes 总被引:4,自引:0,他引:4
Bonan CD Amaral OB Rockenbach IC Walz R Battastini AM Izquierdo I Sarkis JJ 《Neurochemical research》2000,25(6):775-779
The ectonucleotidase pathway is an important metabolic source of extracellular adenosine. Adenosine has potent anticonvulsant effects on various models of epilepsy. One of these models is pentylenetetrazol (PTZ) kindling, in which repeated administration of subconvulsive doses of this drug induces progressive intensification of seizure activity. In this study, we examine the effect of a single convulsive injection (60 mg/kg, i.p.) or 10 successive (35 mg/kg, i.p.) injections of PTZ on synaptosomal ectonucleotidases. Our results have shown that no changes in ectonucleotidase activities were seen at 0, 1, and 24 h or at 5 days after a single convulsive PTZ injection. However, after PTZ-kindling, rats which were more resistant to seizure development presented an increase in ATP hydrolysis in synaptosomes from hippocampus and cerebral cortex (44% and 28%, respectively). These results suggest that changes in nucleotide hydrolysis may represent an important mechanism in the modulation of chronic epileptic activity in this model. 相似文献
9.
10.
Romina F. Vázquez Erasmo Ovalle-García Armando Antillón Iván Ortega-Blake Laura S. Bakás Carlos Muñoz-Garay Sabina M. Maté 《生物化学与生物物理学报:生物膜》2021,1863(1):183467
Sphingolipids-enriched rafts domains are proposed to occur in plasma membranes and to mediate important cellular functions. Notwithstanding, the asymmetric transbilayer distribution of phospholipids that exists in the membrane confers the two leaflets different potentials to form lateral domains as next to no sphingolipids are present in the inner leaflet. How the physical properties of one leaflet can influence the properties of the other and its importance on signal transduction across the membrane are questions still unresolved. In this work, we combined AFM imaging and Force spectroscopy measurements to assess domain formation and to study the nanomechanical properties of asymmetric supported lipid bilayers (SLBs) mimicking membrane rafts. Asymmetric SLBs were formed by incorporating N-palmitoyl-sphingomyelin (16:0SM) into the outer leaflet of preformed 1,2-Dioleoyl-sn-glycero-3-phosphocholine (DOPC)/Cholesterol SLBs through methyl-β-cyclodextrin–mediated lipid exchange. Lipid domains were detected after incorporation of 16:0SM though their phase state varied from gel to liquid ordered (Lo) phase if the procedure was performed at 24 or 37 °C, respectively. When comparing symmetric and asymmetric Lo domains, differences in size and morphology were observed, with asymmetric domains being smaller and more interconnected. Both types of Lo domains showed similar mechanical stability in terms of rupture forces and Young's moduli. Notably, force curves in asymmetric domains presented two rupture events that could be attributed to the sequential rupture of a liquid disordered (Ld) and a Lo phase. Interleaflet coupling in asymmetric Lo domains could also be inferred from those measurements. The experimental approach outlined here would significantly enhance the applicability of membrane models. 相似文献