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1.
A six-year-old arabian stallion was admitted to The Ohio State University Veterinary Hospital for evaluation and repair of a comminuted fracture of the second phalanx. The horse developed impaired arterial oxygenation during surgey and pulmonary edema post-operatively. We postulate that impaired arterial oxygenation resulted from atelectasis of the dependent lung during annesthesia, and the pulmonary edema occurred following re-expansion of the atelectatic of the initiating cause of the edema, removal of excess lung water from the alveoli, and restoration of normal arterial oxygenation. The horse was fully recovered within 12 hours of initiation of clinical signs of respiratory compromise. The horse was fully recovered within 12 hours of initiation of clinical signs of respiratory compromise. This report describes re-expansion pulmonary edema due to reperfusion injury in a horse, treatment of the condition, and a possible explanation of the pathogenesis of this pulmonary pathology.  相似文献   
2.
LIU Ji-yan  WEI Yu-quan 《园艺学报》2004,20(7):1309-1313
Angiogenesis, or the formation of new blood vessels out of pre-existing capillaries, is very important in many physiologic and pathologic processes, such as embryonic development, cancer, retinopathies, etc. Vascular endothelial growth factor receptor-2 (VEGFR-2) plays a key role in angiogenesis. In this review, we discussed the structure, function and signal transduction of vascular endothelial growth factor receptor-2. Understanding these should provide important insights into how new strategies can be devised to interfere in the physiologic and pathologic processes involved in angiogensis.  相似文献   
3.
The right and left lungs of 5 healthy Minipigs and of 13 healthy Landrace piglets were isolated, perfused at constant pressure and maintained in an isogravimetric state under zone III conditions (pulmonary venous pressure>alveolar pressure). By applying the double, arterial and venous, occlusion technique, the total blood flow resistance (R t) was partitioned into four components: arterial (R a), pre-(R a) and post-capillary (R v) and venous (R v). The capillary filtration coefficient (K f,c) was evaluated by measuring the weight gained by the lungs when the arterial and venous pressures were suddenly increased. In the youngest Landrace piglets (5 weeks old), there was an uncontrolled vasoconstriction which sometimes prevented perfusion of the lungs and induced a large increase inR t. These high values ofR t were decreased by tolazoline administration. The values ofR t recorded in older pigs (12–13 weeks old) were lower in Minipigs (33.66±3.77 cmH2O min L–1 per 100 g of lungs;n=5) than in Landrace piglets (55.20±6.18 cmH2O min L–1 per 100 g;n=5). This breed difference was due to the differences inR a andR v. The mean values ofK f,c were 0.193±0.015 and 0.202±0.029 ml min (cmH2O)–1 per 100 g of the lungs in Minipigs and Landrace piglets respectively. All these parameters were stable for the 3 hours following the equilibrium period. It was concluded that: (1) There is an age-related maturation of the control of the vasomotor tone in porcine lungs. (2) Pulmonary microvascular haemodynamics are influenced by the breed of the pigs. (3) There was no difference in theK f,c values between both the breeds. (4) A comparison of the values reported for dogs and rabbits with our data shows that the pre- and post-capillary resistances and, to a lesser extent, the arterial and venous resistances are relatively high in pigs.  相似文献   
4.
FEI Jia  ZHANG Huan 《园艺学报》2003,19(5):645-648
AIM:The effective antisense sequences targeted VEGF mRNA with computer software would be screened and designed, and effect of them on growth K562 cells and protein expression of VEGF were studied with experiments.METHODS:Seven antisense sequences were selected and synthesized, which consisted of 18-20 deoxynucleotide acid and were modified with phosphorothioate, according to principle of low free energy of overall △G37 Overall. Cell growth was assayed by trypan blue dye exclusion assay and level of VEGF protien in the media was determined by ELISA.RESULTS:Six of seven sequences were capable of inhibing growth of K562 cells and downregulating the VEGF protein expression significantly, compared with Scrambed control group. It was found that there was a close correlation between low level of overall △G37 and antisense effectiveness (r=0.887,P<0.01).CONCLUSION:VEGF mRNA antisense oliogdeoxynucleotides, which were designed by computer software of RNAstructure, were able to inhibit growth of K562 and its protein expression. The VEGF mRNA may be new target attached by drugs. At same time, the computer aided design is useful methods to obtain the effective antisense.  相似文献   
5.
AIM: To investigate the effect of cGMP on voltage-gated potassium channel in pulmonary artery smooth muscle cells (PASMCs) from rats exposed to chronic hypoxia. METHODS: (1) Wistar rats were randomly divided into control group (group A) and chronic hypoxia group (group B). Then group B received hypoxia 8 hours per day for 4 consecutive weeks. (2) Single PASMC was obtained via acute enzyme separation method. (3) Conventional whole-cell patch clamp technique was used to record resting membrane potential (Em) and ion currents of voltage-gated potassium channel. The changes of ion currents of voltage-gated potassium channel before and after applying cGMP (1 mmol/L), an agonist of protein kinase G (PKG), and cGMP plus H-8 (1 mmol/L), an inhibitor of PKG were compared between two groups. RESULTS: The Em of group B were significantly lower than that of group A. The ion currents of voltage-gated potassium channel in group A and group B were all significantly inhibited by cGMP [control group: from (118.0±5.0) pA/pF to (89.9±16.5) pA/pF, n=6, P<0.05;chronic hypoxia group: from (81.0±5.0) pA/pF to (56.8±9.1) pA/pF, n=6, P<0.05]and these effects were reversed by H-8 [control group: from (119.2±10.3) pA/pF to (117.8±9.1) pA/pF, n=6, P>0.05;chronic hypoxia group: from (96.8±6.2) pA/pF to (98.0±2.2) pA/pF, n=6, P>0.05]. CONCLUSIONS: The currents of voltage-gated potassium channel was inhibited by chronic hypoxic. The inhibitory effect of cGMP on currents of voltage-gated potassium channel in PASMCs from both normal and chronic hypoxic rats may be probably through the phosphorylation of voltage-gated potassium channel.  相似文献   
6.
AIM:To investigate the expression of soluble guanylate cyclase protein and its mRNA in rat pulmonary artery after exposure to hypoxia and hypercapnia.METHODS:Male Sprague-Dawley rats were randomly split into 4 group, which were hypoxic hypercapnic (HH 1 week, HH 2 weeks, HH 4 weeks) group and control group, to copy pulmonary hypertensive animal model. The expression of sGCα1 and β1 subunits protein of medial and small pulmonary artery was performed by immunohistochemistry with a polycolonal antibody. In situ hybridization was performed on the rat lung tissue using sGC oligonuclear probe to assay the expression of sGCα1subunit mRNA.RESULTS:The sGCα1 and β1 subunits protein and sGCα1 subunit mRNA were faint staining in the pulmonary small and medium artery in HH1 week, HH 2 weeks and HH 4 weeks groups compared with control group (all P<0.01).CONCLUSION:sGC subunit mRNA and protein expression in pulmonary small and medium artery were decreased after exposure to hypoxia and hypercapnia, which took part in the development of the pulmonary hypertension.  相似文献   
7.
AIM: To investigate rat Urotensin-II(rat U-II)-induced vasoconstriction of rat main pulmonary arteries and the role of mitogen-activated protein kinase(MAPK). METHODS: The main pulmonary artery was dissected from the male Sprague-Dawley rats and artery ring width was 3-4 mm. Concentration-response curves were generated to rat U-II(0.03 nmol/L-30 nmol/L).Inhibitor of MAPK, PD 98059(0.1 μmol/L-10 μmol/L) were added into the medium after rat U-II(30 nmol/L)induced vasoconstriction had reached plateau to construct the relaxant concentration-response curves and their EC50 and Emax. RESULTS:Rat U-II was a potent vasoconstrictor of isolated rat main pulmonary arteries [EC50=7.95±0.40, Emax=(14.28±6.34)% of the response to 60 mmol/L KCl]; PD 98059 caused concentration-dependent relaxations of rat U-II precontracted arteries [EC50=5.91±0.45, Emax=(81.39±13.65)%]. CONCLUSION: Rat U-II was a potent vasoconstrictor of rat main pulmonary arteries and this response was mediated through MAPK.  相似文献   
8.
AIM and METHODS: Total RNA was extracted from 6th rat subcultured pulmonary artery smooth muscle cells(PASMC) exposed to continual chronic hypoxia or normoxia and the effects of chronic hypoxia on the changes of Kv1.3,Kv2.1,Kv3.1 mRNA in cultured PASMC induced by acute hypoxia were studied by semiquantitative RT-PCR in vitro. RESULTS:①Kv1.3,Kv2.1,Kv3.1 genes were found to be expressed in PASMC of rats exposed either to hypoxia or normxia.②The expression of Kv2.1 and Kv3.1 in 6th subcultured of PASMC in normaxia group could be upregulated by exposure to acute hypoxia,the levels of Kv2.1 and Kv3.1 mRNA were significantly increased from 0.646±0.092, 0.782±0.104 to 1.059±0.134, 0.985±0.116,respectively (P<0.01,n=5). ③PASMC cultured continuously in chronic hypoxia for 6 subcultures and then exposed to normoxia for 12 h,thereafter the expression of Kv2.1 and Kv3.1 were downregulated by acute hypoxia for 6 hours.The level of Kv2.1 mRNA was significantly decreased from 1.008±0.117 to 0.649±0.097 (P<0.01,n=5). CONCLUSION:Kv2.1,Kv3.1 genes might be oxygen sensitive genes.Chronic hypoxia might change the response of these Kv genes of PASMC to acute hypoxia and down-regulate its expression,which might probably decrease the role of Kv in HPV.  相似文献   
9.
AIM: To investigate the role of potassium channels in the regulation of intracellular free calcium concentration ( [Ca2+]i) of pulmonary artery smooth muscle cells (PASMCs) in rats. METHODS: The fluorescence Ca2+ indicator Fura-2/AM was used to observe [Ca2+]i of rat PASMCs in normal and chronic hypoxic condition. The influences of potassium channels on PASMCs proliferation were assessed by MTT assay. RESULTS: 1. In normoxic condition, [Ca2+]i was (156.91±8.60) nmol/L, and in hypoxic condition, [Ca2+]i was (294.01±16.81) nmol/L. 2. In normoxic condition, the voltage-dependent K+-channel antagonist 4-aminopyridine (4AP), but not the Ca2+-activated K+-channel antagonist tetraethylammonium (TEA) and the ATP-sensitive K+-channel antagonist glibenclamide (Glib) increased [Ca2+]i. 3. In hypoxic condition, 4AP and TEA caused the rise in [Ca2+]i , but Glib had no effect on [Ca2+]i. 4. MTT assay showed that 4AP increased the value of absorbing light degree (A value) in normoxic and hypoxic condition (0.582±0.062,0.873±0.043,respectively, P<0.01), TEA increased A value only in hypoxic condition, and Glib had no effect on the proliferation of PASMCs. CONCLUSIONS: KV plays an important role in the regulation of [Ca2+]i and proliferation of PASMCs. KCa serves as distinct responsive roles in the regulation of proliferation of PASMCs in hypoxic condition. KATP has no effect on [Ca2+]i and proliferation of PASMCs in normoxic and hypoxic conditions.  相似文献   
10.
AIM: To investigate inhibition of K562 cell growth by antisense drug targeted VEGF mRNA. METHODS: X7, 20-mer antisense sequences were selected, synthesized and modified with phosphorothioate. The drug was transfected into K562 cells in the present of lipofection. Cell growth was assayed by trypan blue dye exclusion assay and MTT. The level of VEGF protein in the media was determined by ELISA. The morphology of apoptotic cells were observed by Giemsa staining, and the propotion of apoptotic cells was detected by flow cytometry. RESULTS: The antisense drug inhibited growth of K562 and downregulated expression of VEGF protein significantly, compared with Scrambed control group and showed dose-dependent relation. Signs of apoptosis of K562 cells were not observed. CONCLUSION: Inhibition of K562 cell proliferation, but not cells apoptosis induction is the mechanism of inhibing growth of K562 cells by antisense drug targeted VEGF mRNA. At same time, VEGF has function of promoting K562 cell proliferation, and VEGF mRNA may be a new target attached by drugs.  相似文献   
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