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141.
目的探讨磷酸钙人工骨(CPC)在颈椎前路椎间融合手术中的应用效果。方法2001年4月至2003年10月颈前路手术中应用磷酸钙人工骨栓椎间融合结合钛钢板固定治疗颈椎病17例,颈椎间盘突出症5例,颈椎外伤脱位2例,共24例35个节段。采用JOA评分评价神经功能,X线片判定融合效果。结果随访18±6.5个月,术后无感染,无过敏或毒性反应。JOA评分由术前9.28±2.15分增加到14.65±2.18分(P<0.001)。术后X线片未见CPC骨栓塌陷或移位,钛板和螺钉无松动及折断。术后16.5±6.8个月均获得椎间融合。结论颈椎前路椎间融合手术应用磷酸钙人工骨替代自体骨,经济、安全、简便、效果可靠。 相似文献
142.
Muscle-type phosphofructokinase deficiency (PFKD) causes a hemolytic disorder and exertional myopathy in humans and dogs.
In humans, PFKD is accompanied by a disturbed calcium homeostasis and associated adenine nucleotide dysregulation, which may
potentiate the erythroenzymopathy associated with this inherited disorder. This study shows that canine PFKD also manifests
these erythrocyte abnormalities. Compared to normal, healthy red cells, PFK-deficient erythrocytes contain lower concentrations
of ATP and higher concentrations of IMP and calcium, the latter as per a calcium indicator dye. Adenosine monophosphate deaminase
(AMPD) enriched 5000-fold from canine erythrocytes adsorbs to immobilized calcium–calmodulin and the interaction between these
two proteins activates AMPD through a K
mapp effect. This behavior is similar to that of the human erythrocyte enzyme and provides a potential contributing mechanism
for accelerated adenine nucleotide turnover in canine PFKD. We propose that adenine nucleotide replacement strategies could
benefit the erythroenzymopathy in human and canine PFKD and that the dog model of this disorder is an appropriate vehicle
for further elucidating this hypothesis. 相似文献
143.
D. J. Secrist W. G. L. Kerrick 《Pflügers Archiv : European journal of physiology》1980,384(3):219-229
Changes in the Ca2+ and Sr2+ activation properties of functionally skinned slow-twitch soleus fibers were measured and compared with those of normal fast-twitch extensor digitorum longus (EDL) following cross-reinnervation of soleus with the nerve to EDL. Most of the fibers showed either complete transformation of activation properties (66%) or remained unchanged (34%). The change in sensitivity to divalent cations was correlated with changes in the proteins present in fibers pooled on the basis of their activation properties. The banding patterns of the 35,000- and 37,500-dalton proteins (tropomyosin and troponin T) in cross-reinnervated soleus were correspondingly transformed to those of normal EDL. Slow and fast myosin light chains were present in the pooled cross-reinnervated fibers. Fiber distributions based on activation properties were confirmed by histochemical features. For the first time it has been demonstrated that cross-reinnervation produced changes in the activation properties of soleus fibers and associated changes in the regulatory proteins measured. 相似文献
144.
J. L. Bossu A. Elhamdani A. Feltz F. Tanzi D. Aunis D. Thierse 《Pflügers Archiv : European journal of physiology》1992,420(2):200-207
Isolated bovine capillary endothelial cells have been examined for voltage-dependent Ca entry. All cells displayed a low threshold activity, with the main characteristics of a T-type transient current, when examined using whole-cell recording for activation and inactivation and cell-attached conditions or inside-out patches for the elementary conductance (8 pS). 25% of the cells displayed an additional sustained current in 5 mM CaCl2 above –40 mV, which was enhanced by application of BAY K 8644, but almost insensitive to superfusion with nicardipine. Two types of channels (2.8 and 21 pS, in 110 mM BaCl2) were shown to have a BAY K 8644 sensitivity. The large conductance channels were L-type channels. The smaller events were elicited at more hyperpolarized potentials (by some 30 mV). Their mean open time was 16 ms in control conditions. In presence of BAY K 8644, additional long open times were observed (up to 100 ms as compared to 7.8 ms for the time constants of the slow mode of the L-type channel). We refer to these channels as SB channels: of small conductance and sensitive to BAY K 8644. In the presence of nicardipine, SB channels are not noticeably modified, in contrast to the L-type openings which are abolished. Also, SB open times are close to control values when nicardipine is added after a BAY K 8644 application. We suggest that, at physiological concentrations of divalent ions, an SB-type activity is elicited above –40 mV which generates the low threshold sustained current. 相似文献
145.
Arnaldo Ferroni A. Galli M. Mazzanti 《Pflügers Archiv : European journal of physiology》1996,431(6):954-963
Neuronal cell firing is crucial to nerve-nerve communication. The ability to produce consecutive action potentials is related
to the activation of inward currents after each upstroke. If fast Na current is indeed responsible for the overshoot, it is
still unclear which current drives membrane voltage to the Na threshold. In this study we present evidence that in adult rat
sensory neurones a dihydropyridine-sensitive Ca channel exists in addition to the well characterized L-type, or high-threshold
Ca channel. During stimulated action potential trains, L-type Ca channels open during the excitation wave, whereas activity
of the other dihydropyridine-sensitive Ca channel was observed primarily between action potentials. This second Ca pathway
shows remarkably long openings at negative potentials after a series of positive prepulses. The nerve action potential and
the repetitive firing work as a physiological Ca channel facilitation mechanism. Therefore, we suggest that this novel Ca
conductance provides inward current, between two consecutive action potentials, able to modulate the frequency of neuronal
bursts.
Received: 3 August 1995/Received after revision: 9 October 1995/Accepted: 10 October 1995 相似文献
146.
探讨男性肝硬化患者钙调激素与性激素变化及其临床意义.男性肝硬化患者48例(按Child-Pugh分级分为A、B、C三组), 男性健康对照组43名, 均进行骨密度(BMD)测定, 用免疫放射法(IRMA)及放射免疫法(RIA)测定甲状旁腺激素(PTH)、降钙素(CT)、骨钙素(BGP)、雌二醇(E2)和睾酮(T), 生化检测肝功能、碱性磷酸酶(ALP)、骨性碱性磷酸酶(BLP)及血钙(Ca2 )、磷(P3 ).肝硬化患者与对照组比较血清PTH升高、CT降低、BGP大部分患者降低、E2上升、T降级、E2/T比值升高;血清ALP及BLP均上升,血Ca2 及血P3 均下降, 骨质疏松发病率增高,而且随着肝功能损害加重, 上述变化越显著.男性肝硬化患者钙调激素及性激素紊乱, 导致肝性骨病, 成人以骨质疏松为主, 并随病情发展而趋严重. 相似文献
147.
The regulation of blood vessel diameter is under the control of the autonomic nervous system (as well as hormones and metabolites), sympathetic nerve stimulation evoking depolarizing post-synaptic potentials. Excitatory junction potentials (EJPs) were recorded from vascular smooth muscle cells of guinea-pig small mesenteric arteries (pressurized) following nerve stimulation. Repetitive stimulation (>5Hz) led to summation of EJPs, which evoked spikes and vasoconstriction. Replacing extracellular Na+ with choline (plus atropine) resulted in a decrease in EJP amplitude, but spike amplitude and maximum rate of rise (+Vmax) were unaffected. Decreasing the extracellular Ca2+ concentration produced decreases in EJP amplitude and spike +Vmax, while increasing extracellular Ca2+ resulted in increased EJP amplitude and spike +Vmax. Verapamil and bepridil, agents that depress Ca2+ influx in vascular and visceral smooth muscle, depolarized the membrane and depressed EJPs and spikes at high concentrations (10–5 M and 5×10–6 M, respectively). The data indicate that EJPs are dependent on external Na+ and Ca2+ ions, and that spikes are dependent on Ca2+. Thus, neuromuscular transmission in this muscle is similar to that in non-vascular smooth muscles, such as intestinal muscle and vas deferens.Part of this work has been presented to the Biophysical Society (Zelcer and Sperelakis 1980) and to the American Physiological Society (Zelcer and Sperelakis 1981) 相似文献
148.
Mollie E. Holman John P. Weinrich 《Pflügers Archiv : European journal of physiology》1975,360(2):109-119
Summary The membrane potential of smooth muscle cells in the circular layer of the guinea pig ileum was recorded using intracellular electrodes. Transmural stimulation, in the presence of atropine, caused a transient hyperpolarization, an inhibitory junction potential (IJP). IJP's are thought to result from the action of transmitter released from intramural inhibitory nerves. It has been reported that, in the guinea pig jejunum, the amplitude of the IJP resulting from field stimulation is not altered by changes in the calcium and magnesium ion concentration in the bathing solution. Experiments reported here have shown that the IJP amplitude decreased markedly on reducing the calcium ion concentration and or increasing the magnesium ion concentration. Indirect evidence is presented suggesting that the decrease in amplitude of the IJP is due to a decrease in the amount of transmitter released. 相似文献
149.
丹参酮Ⅱ_A磺酸钠对心肌钙反常的保护作用 总被引:10,自引:1,他引:10
豚鼠离体心脏灌流造成心肌钙反常模型,以丹参酮Ⅱ_A磺酸钠(DS-201)为保护剂,测定心肌组织蛋白释放和钙摄取量,观察作用效果。并与已知钙拮抗剂异搏定比较,探讨DS-201的钙拮抗作用。实验结果表明,DS-201对心肌钙反常损伤具有明显的保护作用,抑制钙内流,减轻钙反常过程中心肌组织钙沉积和心肌损伤所致的蛋白(酶)释放(P<0.01)。该作用在一定范围内具有剂量依赖关系。30mg/L、40mg/LDS-201分别能降低心肌组织蛋白释放量52.8%、66.2%,降低钙摄取量25.8%、36.9%。作用效果优于异搏定,后者降低蛋白释放量47.5%,降低钙摄取量23.9%。 相似文献
150.
A. Völker Klaus Ballanyi D. W. Richter 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》1995,103(1):9-19
Tissue oxygen (PO2), K+ (aKe), pH (pHe) and Ca2+ ([Ca2+]e) were measured in the region of the ventral respiratory group (VRG) in the in vitro brainstem-spinal cord preparation of neonatal rats. During tissue anoxia, elicited by superfusion of N2-gassed solutions, an initial increase in the frequency of respiratory activity, lasting between 2 and 12 min, turned into a frequency depression. During anoxia periods of up to 60 min, respiratory activity persisted in solutions containing CO2/bicarbonate, whereas a complete blockade was observed after 15–25 min in N-2-hydroxyethylpiperazine-N-2-ethanesulfonic acid- (Hepes)-buffered salines. After such anoxic apnea, respiratory rhythmicity could be reactivated by superfusion of hypoxic, CO2/bicarbonate-buffered solutions. In both types of hypoxic solutions, aKe increased by maximally 1.5mM, whereas an initial increase of pHe by up to 0.05 pH units turned, after 2–4 min, into an acidification which could exceed 0.5 pH units. In contrast, [Ca2+]e remained unaffected by anoxia. Addition of 2–5 mM cyanide (CN-) to oxygenated Hepes-buffered saline evoked an increase in PO2 in the VRG from 100 to more than 300 mmHg. The effects of CN- on respiratory activity, aKe and pHe were almost identical to those during anoxia. In oxygenated, CO2/bicarbonatefree solutions of different pH, however, an increase in pHe in the VRG led to a decrease in respiratory frequency, whereas a fall of pHe produced a frequency acceleration. A rise of aKe in the VRG by more than 2 mM as induced by superfusion of a 7 mM K+ solution led to a sustained increase of respiratory frequency. The results indicate that blockade of aerobic metabolism does not severely perturb K+ and Ca2+ homeostasis and that the biphasic response to anoxia is not directly related to the observed changes in PO2, aKe, pHe, or [Ca2+]e. In the respiratory network of neonatal mammals, CO2 might provide a stimulus for long-term maintenance of respiratory activity under oxygen depletion. 相似文献