共查询到20条相似文献,搜索用时 15 毫秒
1.
C A de Carvalho R R de Souza I Fujimura M V de Araujo C F Takakura 《Gegenbaurs morphologisches Jahrbuch》1985,131(6):863-868
The fat cells of the fascia areolaris and fascia lamellaris of men, women, and pregnant women (aged between 20 and 35a) were morphometrically studied. The cell volumes showed the following average values: 4.423 X 10(5) micron3 and 2.004 X 10(5) micron3 for the fasciae areolaris and lamellaris respectively, in men; 6.236 X 10(5) micron3 and 3.964 X 10(5) micron3 in women, and 10.114 X 10(5) micron3 and 4.635 X 10(5) micron3 in the pregnant women. The analysis of variance showed significant differences between both sexes, and fasciae areolaris and lamellaris. The differences between women and pregnant women as far as the cell volume is concerned, in both fasciae, were not significant. As to the fascia areolaris, not the lamellaris, the difference between the sexes was significant. 相似文献
2.
This study describes the gross anatomic variations observed in a 32-week male fetus diagnosed as having otocephaly. Special attention was given to the muscular, peripheral nervous, and vascular systems of the entire body. External features included approximation of the ears on the front of the neck, underdevelopment of the lower jaw, and a small oral cavity. The mandible, maxillae, and zygomatic bones were smaller than normal and appeared shifted in a ventrocaudal direction. The middle ear ossicles were fused and abnormally positioned. The tongue was positioned abnormally and malformed. The muscles of mastication were fused in the midline and formed the floor of the oral cavity. The variations were similar to the spectrum of abnormalities reported in two cases in the literature. Because of this finding, it is possible that the causative events leading to these deviations were similar in the three cases. Possible mechanisms are considered which could lead to the observed malformations seen in these cases. There were also several muscle and nerve anomalies outside of the head region. 相似文献
3.
Trindade VL Martins PA Santos S Parente MP Natal Jorge RM Santos A Santos L Fernandes JM 《Journal of biomechanics》2012,45(1):199-201
The present study focuses on the determination of human temporal tendons and deep temporal fascia biomechanical behavior. The tensile and shear loads generated by the temporal muscle are transmitted to the masticatory system by the temporal tendons and muscle fascia. Establishing these connective tissues' biomechanical properties will help to develop proper finite element-based simulations of the human masticatory system, which will allow better understanding of diseases affecting the temporomandibular joint. The tissues were harvested from 8 male fresh cadavers, who were subjected to uniaxial tension tests. Available literature states that different connective tissues undergo identical biochemical, cellular and mechanical changes during senescence. Several mechanical phenomena occur during maturation, resulting in stiffer, stronger and more stable connective tissues, although less flexible. Based on this evidence, the present study suggests that older temporal tendon and fascia samples are stiffer than younger ones. We also found significant higher secant moduli with increasing age. 相似文献
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E. Plata A. Ballester A. M. Vieitez 《In vitro cellular & developmental biology. Plant》1991,27(4):183-189
Summary An anatomical study was carried out during the sequences of events which lead to the differentiation of secondary embryos
ofCamellia reticulata cv ‘Mouchang’. Secondary embryogenesis can be induced by culturing somatic embryos on a modified Murashige and Skoog medium
supplemented with 0.5 mg·liter−1 6-benzylaminopurine and 0.1 mg·liter−1 indole-3-butyric acid. After about 12 days of culture, globular-shaped secondary embryos became apparent, and by 18 to 20
days of culture cotyledonary stages were formed. Embryos developed mainly on the hypocotyl of primary embryos without an intermediate
callus. Histologic monitoring revealed that secondary embryos apparently had a multicellular origin from embryogenic areas
originating in both epidermal and subepidermal layers of the hypocotyl region. This morphogenetic competence is related to
the presence, at the time of culture, of relatively undifferentiated cells in superfical layers of the primary embryo hypocotyl.
Microcomputer image analysis was applied for quantifying cytological events associated with somatic embryogenesis. This method
showed an increasing gradient in the nucleus-to-cell area ratio from differentiated cells passing through preembryogenic cells
to embryogenic cells. The formation of embryogenic areas was preceded by accumulation of starch in the surrounding cortical
cells. The cells underlying globular secondary embryos still contained abundant starch, but it declined as the secondary embryos
developed. 相似文献
6.
Yoshida A Hirano K Motoyashiki T Morita T Ueki H 《Archives of biochemistry and biophysics》2002,398(2):253-260
In a physiological milieu platelets continue to be exposed to agonists long after clot formation. We studied the regulation of postaggregation events consequent on protease-activated receptor (PAR) 1 ligation with either thrombin or the thrombin receptor-activating peptide (TRAP). Stimulation with TRAP (20 microM) but not with thrombin (1 U/ml) for 15 min evoked platelet disaggregation by about 30% and downregulation of high-affinity fibrinogen binding sites on integrin alpha(IIb)beta(3) to nearly prestimulation levels. Concurrently, only TRAP disorganized the actin-based cytoskeleton, with decrease in the cytoskeletal content of focal contact-associated proteins like integrin alpha(IIb)beta(3), Src, and focal adhesion kinase (FAK). While protein tyrosine kinases were activated during the initial period of platelet aggregation with either agonist, stimulation of protein tyrosine phosphatases determined the successive phase of reduced phosphotyrosine content. SHP-1, an abundant protein tyrosine phosphatase in the platelets, was tyrosine phosphorylated on challenge of PAR-1 and coprecipitated with two unidentified tyrosine phosphorylated proteins of 140 and 60 kDa; in addition, SHP-1 tyrosine phosphorylation (which is associated with enhanced phosphatase activity) was sustained until 15 min. Activity of calpain was upregulated following incubation with thrombin and not with TRAP. Collectively, these data suggest that signaling pathways elicited by PAR-1 agonists thrombin and TRAP are markedly different, which could have important implications on late platelet responses. 相似文献
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The authors report on first observations on the vascularization of the areae mesocolicae which resulted from radioanatomical studies made in collaboration with the Institute of General Clinical Surgery of the University of Siena. Three areae can be distinguished: colocolica (Treitz), sigmoidea or intersigmoidea, and intercolica. The investigations were carried out using selective preoperative angiography and the injection of anatomical preparations. 相似文献
9.
Vanadate stimulated the release of lipoprotein lipase (LPL) activity from rat fat pads into the medium in a time- and dose-dependent manner. It exerted the synergetic effect with heparin. The stimulatory effects of vanadate and heparin were decreased by incubation in Na+- or Ca2+-free media but were well preserved in K+-free medium. Amiloride inhibited the vanadate-stimulated release of LPL activity in a dose-dependent manner, but did not inhibit the heparin-stimulated release of LPL activity. Colchicine, antimycin A, and carbonyl cyanide m-chlorophenylhydrazone suppressed the stimulatory effect of vanadate, but cycloheximide did not. Preincubation of the fat pads with the tetrakis (acetoxymethyl) ester of quin 2 (quin 2-AM) inhibited the vanadate-stimulatory release of LPL activity without affecting basal activity. The concentration required for half-maximal inhibition of the action of vanadate by quin 2-AM was calculated to be 39 microM, suggesting that the action of vandate was dependent on intracellular Ca2+ concentration. The heparin-stimulated release, on the other hand, was not inhibited even at higher concentrations of quin 2-AM (up to 200 microM). These findings suggest that vanadate stimulates the release of LPL activity through mechanisms of action involving amiloride-sensitive and calcium-dependent pathways with a requirement of metabolic energy. 相似文献
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An integrative study of insect adhesion: mechanics and wet adhesion of pretarsal pads in ants 总被引:10,自引:1,他引:9
Many animals that locomote by legs possess adhesive pads. Suchorgans are rapidly releasable and adhesive forces can be controlledduring walking and running. This capacity results from the interactionof adhesive with complex mechanical systems. Here we presentan integrative study of the mechanics and adhesion of smoothattachment pads (arolia) in Asian Weaver ants (Oecophylla smaragdina).Arolia can be unfolded and folded back with each step. Theyare extended either actively by contraction of the claw flexormuscle or passively when legs are pulled toward the body. Regulationof arolium use and surface attachment includes purely mechanicalcontrol inherent in the arrangement of the claw flexor system. Predictions derived from a wet adhesion mechanismwere tested by measuring attachment forces on a smooth surfaceusing a centrifuge technique. Consistent with the behavior ofa viscid secretion, frictional forces per unit contact arealinearly increased with sliding velocity and the increment stronglydecreased with temperature. We studied the nature and dimensions of the adhesive liquidfilm using Interference Reflection Microscopy (IRM). Analysisof footprint droplets showed that they are hydrophobicand form low contact angles. In vivo IRM of insect pads in contactwith glass, however, revealed that the adhesive liquid filmnot only consists of a hydrophobic fluid, but also of a volatile,hydrophilic phase. IRM allows estimation of the height of theliquid film and its viscosity. Preliminary data indicate thatthe adhesive secretion alone is insufficient to explain theobserved friction and that rubbery deformation of the pad cuticleis involved. 相似文献
12.
Baglioni S Cantini G Poli G Francalanci M Squecco R Di Franco A Borgogni E Frontera S Nesi G Liotta F Lucchese M Perigli G Francini F Forti G Serio M Luconi M 《PloS one》2012,7(5):e36569
Metabolic pathologies mainly originate from adipose tissue (AT) dysfunctions. AT differences are associated with fat-depot anatomic distribution in subcutaneous (SAT) and visceral omental (VAT) pads. We address the question whether the functional differences between the two compartments may be present early in the adipose stem cell (ASC) instead of being restricted to the mature adipocytes. Using a specific human ASC model, we evaluated proliferation/differentiation of ASC from abdominal SAT-(S-ASC) and VAT-(V-ASC) paired biopsies in parallel as well as the electrophysiological properties and functional activity of ASC and their in vitro-derived adipocytes. A dramatic difference in proliferation and adipogenic potential was observed between the two ASC populations, S-ASC having a growth rate and adipogenic potential significantly higher than V-ASC and giving rise to more functional and better organized adipocytes. To our knowledge, this is the first comprehensive electrophysiological analysis of ASC and derived-adipocytes, showing electrophysiological properties, such as membrane potential, capacitance and K(+)-current parameters which confirm the better functionality of S-ASC and their derived adipocytes. We document the greater ability of S-ASC-derived adipocytes to secrete adiponectin and their reduced susceptibility to lipolysis. These features may account for the metabolic differences observed between the SAT and VAT. Our findings suggest that VAT and SAT functional differences originate at the level of the adult ASC which maintains a memory of its fat pad of origin. Such stem cell differences may account for differential adipose depot susceptibility to the development of metabolic dysfunction and may represent a suitable target for specific therapeutic approaches. 相似文献
13.
Vanadate increased lipoprotein lipase (LPL) activity in the isolated fat pads in a time- and dose-dependent manner. The increasing effect of vanadate was inhibited by amiloride, similar to that of insulin, and it also was not additive to that of insulin. Although the increasing effects of vanadate and insulin were preserved in K(+)-free medium, appreciable decreases in both effects were observed by replacement of Na+ with choline ion or omission of Ca2+ in the medium. Vanadate showed the full effect in the presence of cycloheximide at concentrations that inhibited protein synthesis of the fat pads, suggesting that the action of vanadate is not due to the increase in protein synthesis. Tetrakis (acetoxymethyl) ester of quin 2 at 50 microM concentration never inhibited the action of vanadate though it showed a little inhibition at a concentration of 300 microM. No inhibition of the action of vanadate was observed with ruthenium red. These results suggest that vanadate increases the LPL activity via a process less sensitive to the intracellular Ca2+ concentration. Adrenaline, dibutyryl cyclic AMP, and 3-isobutyl-1-methylxanthine all inhibited the action of vanadate, suggesting that the action is inhibited with increase in the intracellular concentration of cyclic AMP. Monensin and carbonyl cyanide m-chlorophenylhydrazone inhibited the action of vanadate. In contrast, the action of insulin was never inhibited by monensin. Tunicamycin and 2-deoxyglucose, at rather high concentrations, inhibited both actions. These findings suggest that vanadate increases the LPL activity through mechanisms of action involving amiloride- and monensin-sensitive pathways dependent on energy. 相似文献
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R G Wolfe R Nakayama D Holten 《Biochemical and biophysical research communications》1979,89(1):108-115
The relative rate of synthesis of glucose-6-P dehydrogenase increases up to 8-fold when fasted rats are fed a 60% carbohydrate, fat-free diet for 3 days but the specific activity of the enzyme only increases 2 to 3 fold. This suggests that the high carbohydrate diet also causes a 2 to 3 fold increase in the rate of glucose-6-P dehydrogenase degradation. The nutritional induction of this enzyme in adipose tissue is primarily due to a large increase in the rate of its synthesis. 相似文献
17.
P. H. J. Nafstad 《Cell and tissue research》1967,76(4):532-542
Summary Morphology and distribution of the perforant path fibres in the hippocampus and the fascia dentata of the rat have been studied in the electron microscope. Investigations were carried out on normal tissue as well as on tissue degenerating after entorhinal damage. The perforant path fibres were relatively thin and the terminals small. Two terminal fields were found to be of quantitative importance, one in the middle third of stratum moleculare of the fascia dentata, the other in stratum lacunosum moleculare of regio inferior of the hippocampus. Some of the observations have been expressed in numerical terms.This study was supported in part by Grant NB 02215 from the National Institute of Neurological Diseases and Blindness, U.S. Public Health Service. 相似文献
18.
A successful embalming procedure necessary for long-lasting preservation of the cadaver and its subsequent anatomical dissection has been undertaken in our laboratory. In short, the procedure consists of a preembalming treatment with blood clot disperser, removal of blood clots, drainage of blood, and arterial embalming with an embalming machine via both carotid and femoral triangles of the body. The embalming fluid is prepared from methyl alcohol and a small amount of formalin as the fixatives, ethylene glycol as a preservative, and liquefied phenol as a mould preventive. Coloring of the blood vessels is also useful in their identification. Other matters relevant to embalming problems are also discussed. 相似文献
19.
A little is known about proteoglycan (PG) changes, occuring in the course of scarring of tissues another than skin. The aim of present study was biochemical characterization of glycosaminoglycans (GAGs) and proteoglycans (PGs) of normal and scarred fascia. Samples of normal fascia lata were taken at autopsy from 23 individuals and samples of scarred fascia lata were removed from 23 patients at reoperations for femoral fracture. The obtained tissues were divided into two samples: first of them was submitted to GAG isolation and the second one to PG isolation.GAGs were extracted by extensive papain digestion followed by the fractionation using cetylpyridinium chloride. In order to qualitative and quantitative characterization GAGs were submitted to electrophoresis on cellulose acetate before and after treatment with enzymes, specifically depolymerizing some kinds of GAGs. PGs were extracted using 4 M guanidine HCl followed by purification by forming complexes with Alcian blue. PGs were submitted to gel permeation chromatography on Sepharose 4B. In order to obtain core proteins PGs were depolymerized with chondroitinase ABC. The purified PGs and their core proteins were separated with sodium dodecyl sulphate/polyacrylamide gel electrophoresis (SDS/PAGE). It was found that total GAGs content was significantly elevated in scarred fascia. Both types of fascia contained chondroitin-, dermatan- and heparan sulphates and hyaluronic acid. Dermatan sulphates (DS) were the predominant GAGs of normal and scarred fascia. The contents of all GAG types were increased in scarred fascia. Both types of fascia contained two kinds of dermatan sulphate proteoglycans (DSPGs); first being similar to biglycan and the second one similar to decorin, as it was judged by molecular weight of their native molecules and core proteins as well as type of GAG components. Densitometric analysis showed that decorin is a predominant DSPG in both fascia types, but in scarred tissue the ratio of biglycan to decorin is considerably higher. Moreover, in scarred fascia a large chondroitin sulphate proteoglycan (CSPG) was also observed. The obtained results have shown that the scar formation is accompanied by quantitative and qualitative alterations in GAGs/PGs resembling those observed in hypertrophic skin scars. The biochemical modification of the scarred fascia lata may partly explain the clinically manifested damage to biomechanical properties of this tissue. 相似文献
20.
Anti-leptin receptor antibody mimics the stimulation of lipolysis induced by leptin in isolated mouse fat pads 总被引:4,自引:0,他引:4
An anti-leptin receptor polyclonal antibody (receptor antibody), as well as leptin, stimulated the release of free fatty acids from isolated mouse fat pads in a time-dependent manner. Following a 90-min incubation, maximal lipolysis was observed at 6 microg/ml receptor antibody and 0.1 nM leptin. The receptor antibody did not show any additive effect to the stimulation of lipolysis induced by leptin, suggesting that they exert their actions through a similar mechanism involving the leptin receptor. N-[2-(p-bromocinnamylamino)ethyl]-5-isoquinolinesulfonamide (H-89), quin 2-AM, N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7), and neomycin sulfate (neomycin) all potently inhibited the stimulation of lipolysis by the receptor antibody and leptin. Short-term incubation of the fat pads with the receptor antibody or leptin showed a transient increase in the cellular content of cAMP and myo-inositol 1,4,5-trisphosphate (IP3) in similar concentrations to the free fatty acid release. Quin 2-AM and W-7 also inhibited the increase in cAMP content, suggesting that a Ca(2)+/calmodulin-dependent process may be involved in a part of the mechanism in which the receptor antibody and leptin exert their effects. The increase in cellular IP3 content via phosphoinositide-specific phospholipase C (PLC) sensitive to neomycin appears to be a primary step to initiate intracellular events. Both the receptor antibody and leptin may stimulate the lipolysis through mechanisms involving a transient increase in the cellular IP3 content followed by cAMP production, which leads to the activation of cAMP-dependent protein kinase. 相似文献