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3.
PLoS One ; 18(11): e0294258, 2023.
Article in English | MEDLINE | ID: mdl-38019748

ABSTRACT

To investigate the evolution and stability characteristics of granite thermal damage, a series of Brazilian splitting tests is conducted on high-temperature granite samples using digital image correlation (DIC) technology. The results show that the Brazilian tensile strength and P-wave velocity exhibit a clear decline beyond a temperature threshold of 450~600°C, with a linear relationship between them. The presence of micro-cracks alters the stress transfer path, disrupting the stress balance on the Brazilian disc and leading to complex fracture patterns. At temperatures below 450°C, high strain areas and the development of micro-cracks occur at both the upper and lower loading ends of the granite Brazilian disc. However, these phenomena are only observed at the upper loading end when the temperature exceeds 450°C. Thermal cracks also cause changes in the internal structure of rock samples, and temperature variations can affect both the P-wave velocity and tensile strength. In terms of the relationship between P-wave velocity and Brazilian tensile strength (BTS) of high-temperature granite under water cooling, the negative exponential function model proposed in this study fits the experimental data very well.


Subject(s)
Fractures, Stress , Humans , Temperature , Brazil , Water
4.
Braz J Microbiol ; 54(2): 645-653, 2023 Jun.
Article in English | MEDLINE | ID: mdl-36808308

ABSTRACT

Integron can capture and express antimicrobial resistance gene cassettes and plays important roles in horizontal gene transfer. The establishment of a complete in vitro reaction system will help to reveal integron integrase mediated site-specific recombination process and regulation mechanism. As an enzymatic reaction, the concentration of integrase is assumed to have a great influence on the reaction rate. To determine the influence of different concentrations of integrase on the reaction rate and to find the best range of enzyme concentration were essential to optimizing the in vitro reaction system. In this study, plasmids with gradient transcription levels of class 2 integron integrase gene intI2 under different promoters were constructed. Among plasmids pI2W16, pINTI2N, pI2W, and pI2NW, intI2 transcription levels ranged from about 0.61-fold to 49.65-fold of that in pINTI2N. And the frequencies of gene cassette sat2 integration and excision catalyzed by IntI2 were positively correlated with the transcription levels of intI2 within this range. Western blotting results indicated high expression of IntI2 partly existed in the form of an inclusion body. When compared with Pc of class 1 integron, the spacer sequence of PintI2 can increase the strength of PcW but decrease the strength of PcS. In conclusion, the frequencies of gene cassette integration and excision were positively correlated with the concentration of IntI2. intI2 driving by PcW with PintI2 spacer sequence can obtain the optimum IntI2 concentration required to achieve the maximum recombination efficiency in vivo in this study.


Subject(s)
Integrases , Integrons , Integrons/genetics , Integrases/genetics , Integrases/metabolism , Mutagenesis, Insertional , Promoter Regions, Genetic , Plasmids/genetics
5.
Braz. J. Anesth. (Impr.) ; 72(6): 768-773, Nov.-Dec. 2022. tab, graf
Article in English | LILACS | ID: biblio-1420611

ABSTRACT

Abstract Background Dexmedetomidine (Dex) is widely used, and its most common side effect is bradycardia. The complete mechanism through which Dex induces bradycardia has not been elucidated. This research investigates the expression of gap junction proteins Connexin30.2 (Cx30.2) and Connexin40 (Cx40) within the sinoatrial node of rats with Dex-induced sinus bradycardia. Methods Eighty rats were randomly assigned to five groups. Saline was administered to rats in Group C. In the other four groups, the rats were administered Dex to induce bradycardia. In groups D1and D2, the rats were administered Dex at a loading dose of 30 μg.kg−1 and 100 μg.kg−1 for 10 min, then at 15 μg.kg−1.h−1 and 50 μg.kg−1.h−1 for 120 min separately. The rats in group D1A and D2A were administered Dex in the same way as in group D1and D2; however, immediately after the administration of the loading dose, 0.5 mg atropine was administered intravenously, and then at 0.5 mg.kg−1.h−1 for 120 min. The sinoatrial node was acquired after intravenous infusion was completed. Quantitative real-time polymerase chain reaction and western blot analyses were performed to measure mRNA and protein expression of Cx30.2 and Cx40, respectively. Results The expression of Cx30.2 increased, whereas the expression of Cx40 decreased within the sinoatrial node of rats with Dex-induced sinus bradycardia. Atropine reversed the effects of Dex on the expression of gap junction proteins. Conclusion Dex possibly altered the expression of gap junction proteins to slow down cardiac conduction velocity in the sinoatrial node.


Subject(s)
Animals , Rats , Sinoatrial Node/metabolism , Dexmedetomidine , Arrhythmias, Cardiac , Atropine Derivatives/metabolism , Bradycardia/chemically induced , Connexins/genetics , Connexins/metabolism
6.
Braz J Anesthesiol ; 72(6): 768-773, 2022.
Article in English | MEDLINE | ID: mdl-35618083

ABSTRACT

BACKGROUND: Dexmedetomidine (Dex) is widely used, and its most common side effect is bradycardia. The complete mechanism through which Dex induces bradycardia has not been elucidated. This research investigates the expression of gap junction proteins Connexin30.2 (Cx30.2) and Connexin40 (Cx40) within the sinoatrial node of rats with Dex-induced sinus bradycardia. METHODS: Eighty rats were randomly assigned to five groups. Saline was administered to rats in Group C. In the other four groups, the rats were administered Dex to induce bradycardia. In groups D1 and D2, the rats were administered Dex at a loading dose of 30 µg.kg-1 and 100 µg.kg-1 for 10 min, then at 15 µg.kg-1.h-1 and 50 µg.kg-1.h-1 for 120 min separately. The rats in group D1A and D2A were administered Dex in the same way as in group D1 and D2; however, immediately after the administration of the loading dose, 0.5 mg atropine was administered intravenously, and then at 0.5 mg.kg-1.h-1 for 120 min. The sinoatrial node was acquired after intravenous infusion was completed. Quantitative real-time polymerase chain reaction and western blot analyses were performed to measure mRNA and protein expression of Cx30.2 and Cx40, respectively. RESULTS: The expression of Cx30.2 increased, whereas the expression of Cx40 decreased within the sinoatrial node of rats with Dex-induced sinus bradycardia. Atropine reversed the effects of Dex on the expression of gap junction proteins. CONCLUSION: Dex possibly altered the expression of gap junction proteins to slow down cardiac conduction velocity in the sinoatrial node.


Subject(s)
Dexmedetomidine , Sinoatrial Node , Rats , Animals , Sinoatrial Node/metabolism , Bradycardia/chemically induced , Connexins/genetics , Connexins/metabolism , Arrhythmias, Cardiac , Atropine Derivatives/metabolism
7.
Electron. j. biotechnol ; Electron. j. biotechnol;45: 19-29, May 15, 2020. tab, ilus, graf
Article in English | LILACS | ID: biblio-1177401

ABSTRACT

BACKGROUND: Long non-coding RNAs (lncRNAs), as post-transcriptional regulators, were thought to function in the inductive property of dermal papilla cells (DPCs) in cashmere goat. Previously, lncRNA-599554 was identified in secondary hair follicle (SHF) of cashmere goat, but its functional significance is unknown. RESULTS: In the present investigation, we verified that lncRNA-599554 had significantly higher expression at the anagen dermal papilla of cashmere goat SHF than that at telogen. Based on overexpression and knockdown techniques, we found that lncRNA-599554 contributes the inductive property of DPCs of cashmere goat, which was assessed by detecting the changes in the expression of several typical indictor genes in DPCs including ET-1, SCF, Versican, ALP, Lef1 and Ptc-1. Based on RNA pull-down assay, we verified that lncRNA-599554 directly interacted with chi-miR-15a-5p. Also, we showed that lncRNA-599554 positively regulated the Wnt3a expression in DPCs but which did not appear to involve its modulating of promoter methylation. Based on the use of Dual-luciferase reporter assays, our data indicated that lncRNA-599554 regulated the Wnt3a expression through chi-miR-15a-5p-mediated post-transcriptional level. CONCLUSIONS: We showed that lncRNA-599554 contributes the inductive property of DPCs in cashmere goat which might be achieved through sponging chi-miR-15b-5p to promote the Wnt3a expression. The results from the present investigation provided a novel insight into the functional mechanism of lncRNA-599554 in the SHF regeneration of cashmere goat along with the formation and growth of cashmere fiber.


Subject(s)
Animals , Hair Follicle/cytology , Hair Follicle/metabolism , Dermis/cytology , Wnt3A Protein/metabolism , RNA, Long Noncoding/metabolism , Biological Assay/methods , Goats , RNA, Long Noncoding/genetics , Luciferases , Methylation
8.
J Pediatr ; 220: 125-131.e5, 2020 05.
Article in English | MEDLINE | ID: mdl-32093934

ABSTRACT

OBJECTIVES: To assess clinical indication-specific antibiotic prescribing in pediatric practice in China based on the World Health Organization (WHO) Access, Watch, and Reserve (AWaRe) metrics and to detect potential problem areas. STUDY DESIGN: Pediatric prescription records on the 16th of each month during 2018 were sampled for all encounters at outpatient and emergency departments of 16 tertiary care hospitals via hospital information systems. Antibiotic prescribing patterns were analyzed across and within diagnostic conditions according to WHO AWaRe metrics and Anatomical Therapeutic Chemical (ATC) classification. RESULTS: A total of 260 001 pediatric encounters were assessed, and antibiotics were prescribed in 94 453 (36.3%). In 35 167 encounters (37.2%), at least 1 intravenous antibiotic was administered. WHO Watch group antibiotics accounted for 82.2% (n = 84 176) of all antibiotic therapies. Azithromycin (n = 15 791; 15.4%) was the most commonly prescribed antibiotic, and third-generation cephalosporins (n = 44 387; 43.3%) were the most commonly prescribed antibiotic class. In at least 66 098 encounters (70.0%), antibiotics were prescribed for respiratory tract conditions, mainly for bronchitis/bronchiolitis (n = 25 815; 27.3%), upper respiratory tract infection (n = 25 184; 26.7%), and pneumonia (n = 13 392; 14.2%). CONCLUSIONS: Overuse and misuse of WHO Watch group antibiotics for respiratory tract conditions and viral infectious diseases is common in pediatric outpatients in China. Pediatric antimicrobial stewardship should be strengthened using WHO AWaRe metrics.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Drug Prescriptions/statistics & numerical data , Drug Utilization/statistics & numerical data , Practice Patterns, Physicians' , Adolescent , Anti-Bacterial Agents/classification , Child , Child, Preschool , China , Cross-Sectional Studies , Humans , Infant , Prospective Studies , World Health Organization
9.
Arch. argent. pediatr ; 115(3): 274-277, jun. 2017.
Article in English, Spanish | LILACS, BINACIS | ID: biblio-1038370

ABSTRACT

Antecedentes/Objetivo. Describir el perfil epidemiológico de la portación nasal de cepas de Staphylococcus aureus (S. aureus), su resistencia a antibióticos y la presencia de los genes de leucocidina de Panton-Valentine (LPV) y mecA en niños en edad escolar que viven en zonas de gran altitud del sudoeste de China. Métodos. En el estudio transversal, se analizaron hisopados nasales de estudiantes a fin de detectar S. aureus. Se realizó la prueba de la reacción en cadena de la polimerasa (RCP) para identificar los genes de LPV y mecA. Resultados. Del total de 314 niños, se detectó S. aureus en el 5,10% (16/314). La resistencia de las cepas aisladas a la penicilina, eritromicina, clindamicina, rifampicina y cefoxitina fue del 100%, 81,3%, 81,3%, 0,0% y 6,3%, respectivamente. Ninguna de las cepas mostró resistencia a la vancomicina. Se detectó la expresión del gen mecA en 3 cepas aisladas, y 10 cepas aisladas dieron resultado positivo para el gen de LPV. Conclusión. Se detectó S. Aureus en el 5,10% (16/314) de la población del estudio; el 0,96% (3 /314) presentó S. Aureus resistente a la meticilina (SARM). Además, se detectó la expresión de los genes de LPV y mecA en 10 y 3 cepas aisladas, respectivamente.


Background/Aim. To describe the epidemiological profile of nasal carriage of Staphylococcus aureus (S. aureus) strains, its antibiotic resistance and mecA and Panton Valentine leukocidin (PVL) genes presence, in school children residing in high altitude areas of Southwestern China. Methods. The cross sectional study screened nasal swabs taken from students for S. aureus. PCR was performed to identify mecA and PVL genes. Results. Of the total 314 children 5.10% (16/314) was detected S. aureus. The resistance of isolated strains to penicillin, erythromycin, clindamycin, rifampicin and cefoxitin was 100%, 81.3%, 81.3%, 0.0%, and 6.3% respectively. No strains demonstrated resistance to vancomycin; expression of mecA gene was detected in 3 isolates and 10 isolates were PVL-positive. Conclusion. S. aureus was detected in 5.10% (16/314) of the study population; 0.96% (3/314) had methicillin resistant S. aureus (MRSA); expression of the mecA and PVL genes were detected in 3 and 10 isolates respectively.


Subject(s)
Humans , Male , Female , Child , Staphylococcus aureus/drug effects , Carrier State/microbiology , Nose/microbiology , Altitude , Staphylococcus aureus/isolation & purification , Staphylococcus aureus/genetics , Bacterial Proteins/genetics , Bacterial Toxins/genetics , China , Cross-Sectional Studies , Drug Resistance, Bacterial , Penicillin-Binding Proteins/genetics , Exotoxins/genetics , Leukocidins/genetics
10.
Arch Argent Pediatr ; 115(3): 274-277, 2017 06 01.
Article in English, Spanish | MEDLINE | ID: mdl-28504494

ABSTRACT

BACKGROUND/AIM: To describe the epidemiological profile of nasal carriage of Staphylococcus aureus (S. aureus) strains, its antibiotic resistance and mecA and Panton Valentine leukocidin (PVL) genes presence, in school children residing in high altitude areas of Southwestern China. METHODS: The cross sectional study screened nasal swabs taken from students for S.aureus. PCR was performed to identify mecA and PVL genes. RESULTS: Of the total 314 children 5.10% (16/314) was detected S.aureus. The resistance of isolated strains to penicillin, erythromycin, clindamycin, rifampicin and cefoxitin was 100%, 81.3%, 81.3%, 0.0%, and 6.3% respectively. No strains demonstrated resistance to vancomycin; expression of mecA gene was detected in 3 isolates and 10 isolates were PVL-positive. CONCLUSION: S. aureus was detected in 5.10% (16/314) of the study population; 0.96% (3/314) had methicillin resistant S.aureus (MRSA); expression of the mecA and PVL genes were detected in 3 and 10 isolates respectively.


ANTECEDENTES Y OBJETIVO: Describir el perfil epidemiológico de la portación nasal de cepas de Staphylococcus aureus (S. aureus), su resistencia a antibióticos y la presencia de los genes de leucocidina de Panton-Valentine (LPV) y mecA en niños en edad escolar que viven en zonas de gran altitud del sudoeste de China. MÉTODOS: Describir el perfil epidemiológico de la portación nasal de cepas de Staphylococcus aureus (S. aureus), su resistencia a antibióticos y la presencia de los genes de leucocidina de Panton-Valentine (LPV) y mecA en niños en edad escolar que viven en zonas de gran altitud del sudoeste de China. RESULTADOS: Del total de 314 niños, se detectó S. aureus en el 5,10% (16/314). La resistencia de las cepas aisladas a la penicilina, eritromicina, clindamicina, rifampicina y cefoxitina fue del 100%, 81,3%, 81,3%, 0,0% y 6,3%, respectivamente. Ninguna de las cepas mostró resistencia a la vancomicina. Se detectó la expresión del gen mecA en 3 cepas aisladas, y 10 cepas aisladas dieron resultado positivo para el gen de LPV. CONCLUSIÓN: Se detectó S. Aureus en el 5,10% (16/314) de la población del estudio; el 0,96% (3 / 314) presentó S. Aureus resistente a la meticilina (SARM). Además, se detectó la expresión de los genes de LPV y mecA en 10 y 3 cepas aisladas, respectivamente.


Subject(s)
Altitude , Carrier State/microbiology , Nose/microbiology , Staphylococcus aureus/drug effects , Staphylococcus aureus/isolation & purification , Bacterial Proteins/genetics , Bacterial Toxins/genetics , Child , China , Cross-Sectional Studies , Drug Resistance, Bacterial , Exotoxins/genetics , Female , Humans , Leukocidins/genetics , Male , Penicillin-Binding Proteins/genetics , Staphylococcus aureus/genetics
11.
Int Braz J Urol ; 42(2): 302-11, 2016.
Article in English | MEDLINE | ID: mdl-27256185

ABSTRACT

PURPOSE: To determine risk factors of postoperative urethral stricture (US) and vesical neck contracture (BNC) after transurethral resection of prostate (TURP) from perioperative parameters. MATERIALS AND METHODS: 373 patients underwent TURP in a Chinese center for lower urinary tract symptoms suggestive of benign prostatic obstruction (LUTS/BPO), with their perioperative and follow-up clinical data being collected. Univariate analyses were used to determine variables which had correlation with the incidence of US and BNC before logistic regression being applied to find out independent risk factors. RESULTS: The median follow-up was 29.3 months with the incidence of US and BNC being 7.8% and 5.4% respectively. Resection speed, reduction in hemoglobin (ΔHb) and hematocrit (ΔHCT) levels, incidence of urethral mucosa rupture, re-catheterization and continuous infection had significant correlation with US, while PSA level, storage score, total prostate volume (TPV), transitional zone volume (TZV), transitional zone index (TZI), resection time and resected gland weight had significant correlation with BNC. Lower resection speed (OR=0.48), urethral mucosa rupture (OR=2.44) and continuous infection (OR=1.49) as well as higher storage score (OR=2.51) and lower TPV (OR=0.15) were found to be the independent risk factors of US and BNC respectively. CONCLUSIONS: Lower resection speed, intraoperative urethral mucosa rupture and postoperative continuous infection were associated with a higher risk of US while severer storage phase symptom and smaller prostate size were associated with a higher risk of BNC after TURP.


Subject(s)
Contracture/etiology , Postoperative Complications/etiology , Prostatic Hyperplasia/surgery , Transurethral Resection of Prostate/adverse effects , Urethral Stricture/etiology , Urinary Bladder Neck Obstruction/etiology , Aged , Humans , Logistic Models , Lower Urinary Tract Symptoms/surgery , Male , Middle Aged , Prospective Studies , ROC Curve , Risk Assessment/methods , Risk Factors , Time Factors , Treatment Outcome
12.
Int. braz. j. urol ; 42(2): 302-311, Mar.-Apr. 2016. tab, graf
Article in English | LILACS | ID: lil-782843

ABSTRACT

ABSTRACT Purpose: To determine risk factors of postoperative urethral stricture (US) and vesical neck contracture (BNC) after transurethral resection of prostate (TURP) from perioperative parameters. Materials and Methods: 373 patients underwent TURP in a Chinese center for lower urinary tract symptoms suggestive of benign prostatic obstruction (LUTS/BPO), with their perioperative and follow-up clinical data being collected. Univariate analyses were used to determine variables which had correlation with the incidence of US and BNC before logistic regression being applied to find out independent risk factors. Results: The median follow-up was 29.3 months with the incidence of US and BNC being 7.8% and 5.4% respectively. Resection speed, reduction in hemoglobin (ΔHb) and hematocrit (ΔHCT) levels, incidence of urethral mucosa rupture, re-catheterization and continuous infection had significant correlation with US, while PSA level, storage score, total prostate volume (TPV), transitional zone volume (TZV), transitional zone index (TZI), resection time and resected gland weight had significant correlation with BNC. Lower resection speed (OR=0.48), urethral mucosa rupture (OR=2.44) and continuous infection (OR=1.49) as well as higher storage score (OR=2.51) and lower TPV (OR=0.15) were found to be the independent risk factors of US and BNC respectively. Conclusions: Lower resection speed, intraoperative urethral mucosa rupture and postoperative continuous infection were associated with a higher risk of US while severer storage phase symptom and smaller prostate size were associated with a higher risk of BNC after TURP.


Subject(s)
Humans , Male , Postoperative Complications/etiology , Prostatic Hyperplasia/surgery , Urethral Stricture/etiology , Urinary Bladder Neck Obstruction/etiology , Contracture/etiology , Transurethral Resection of Prostate/adverse effects , Time Factors , Logistic Models , Prospective Studies , Risk Factors , ROC Curve , Treatment Outcome , Risk Assessment/methods , Lower Urinary Tract Symptoms/surgery , Middle Aged
13.
Pestic Biochem Physiol ; 122: 15-21, 2015 Jul.
Article in English | MEDLINE | ID: mdl-26071802

ABSTRACT

Fall armyworm (FAW) is a damaging pest of many economic crops. Long-term use of chemical control prompted resistance development to many insecticide classes. Many populations were found to be significantly less susceptible to major Bt toxins expressed in transgenic crops. In this study, a FAW strain collected from Puerto Rico (PR) with 7717-fold Cry1F-resistance was examined to determine if it had also developed multiple/cross resistance to non-Bt insecticides. Dose response assays showed that the PR strain developed 19-fold resistance to acephate. Besides having a slightly smaller larval body weight and length, PR also evolved a deep (2.8%) molecular divergence in mitochondrial oxidase subunit II. Further examination of enzyme activities in the midgut of PR larvae exhibited substantial decreases of alkaline phosphatase (ALP), aminopeptidase (APN), 1-NA- and 2-NA-specific esterase, trypsin, and chymotrypsin activities, and significant increases of PNPA-specific esterase and glutathione S-transferase (GST) activities. When enzyme preparations from the whole larval body were examined, all three esterase, GST, trypsin, and chymotrypsin activities were significantly elevated in the PR strain, while ALP and APN activities were not significantly different from those of susceptible strain. Data indicated that multiple/cross resistances may have developed in the PR strain to both Bt toxins and conventional insecticides. Consistently reduced ALP provided evidence to support an ALP-mediated Bt resistance mechanism. Esterases and GSTs may be associated with acephate resistance through elevated metabolic detoxification. Further studies are needed to clarify whether and how esterases, GSTs, and other enzymes (such as P450s) are involved in cross resistance development to Bt and other insecticide classes.


Subject(s)
Bacterial Proteins/pharmacology , Endotoxins/pharmacology , Hemolysin Proteins/pharmacology , Insecticide Resistance/genetics , Insecticides/pharmacology , Organophosphates/pharmacology , Spodoptera/drug effects , Alkaline Phosphatase/metabolism , Animals , Bacillus thuringiensis Toxins , Bacterial Proteins/genetics , Base Sequence , Drug Resistance, Multiple/genetics , Electron Transport Complex IV/genetics , Electron Transport Complex IV/metabolism , Endotoxins/genetics , Enzymes/metabolism , Glutathione Transferase/metabolism , Hemolysin Proteins/genetics , Inactivation, Metabolic , Insect Proteins/metabolism , Molecular Sequence Data , Organothiophosphorus Compounds/pharmacology , Phosphoramides/pharmacology , Puerto Rico , Spodoptera/genetics , Spodoptera/metabolism
14.
Clinics (Sao Paulo) ; 68(2): 263-8, 2013.
Article in English | MEDLINE | ID: mdl-23525325

ABSTRACT

OBJECTIVE: Ischemia reperfusion injury is partly responsible for the high mortality associated with induced myocardial injury and the reduction in the full benefit of myocardial reperfusion. Remote ischemic preconditioning, perconditioning, and postconditioning have all been shown to be cardioprotective. However, it is still unknown which one is the most beneficial. To examine this issue, we used adult male Wistar rat ischemia reperfusion models to compare the cardioprotective effect of these three approaches applied on double-sided hind limbs. METHODS: The rats were randomly distributed to the following five groups: sham, ischemia reperfusion, remote preconditioning, remote perconditioning, and remote post-conditioning. The ischemia/reperfusion model was established by sternotomy followed by a 30-min ligation of the left coronary artery and a subsequent 3-h reperfusion. Remote conditioning was induced with three 5-min ischemia/5-min reperfusion cycles of the double-sided hind limbs using a tourniquet. RESULTS: A lower early reperfusion arrhythmia score (1.50 + 0.97) was found in the rats treated with remote perconditioning compared to those in the ischemia reperfusion group (2.33 + 0.71). Meanwhile, reduced infarct size was also observed (15.27 + 5.19% in remote perconditioning, 14.53 + 3.45% in remote preconditioning, and 19.84+5.85% in remote post-conditioning vs. 34.47 + 7.13% in ischemia reperfusion, p<0.05), as well as higher expression levels of the apoptosis-relevant protein Bcl-2/Bax following global (ischemia/reperfusion) injury in in vivo rat heart models (1.255 + 0.053 in remote perconditioning, 1.463 + 0.290 in remote preconditioning, and 1.461 +0.541 in remote post-conditioning vs. 1.003 + 0.159 in ischemia reperfusion, p<0.05). CONCLUSION: Three remote conditioning strategies implemented with episodes of double-sided hind limb ischemia/reperfusion have similar therapeutic potential for cardiac ischemia/reperfusion injury, and remote perconditioning has a greater ability to prevent reperfusion arrhythmia.


Subject(s)
Ischemic Preconditioning, Myocardial/methods , Myocardial Reperfusion Injury/therapy , Animals , Arrhythmias, Cardiac/physiopathology , Male , Myocardial Infarction/prevention & control , Random Allocation , Rats , Rats, Wistar , Time Factors , Treatment Outcome , Ventricular Function/physiology
15.
Clinics ; Clinics;68(2): 263-268, 2013. ilus, tab
Article in English | LILACS | ID: lil-668816

ABSTRACT

OBJECTIVE: Ischemia reperfusion injury is partly responsible for the high mortality associated with induced myocardial injury and the reduction in the full benefit of myocardial reperfusion. Remote ischemic preconditioning, perconditioning, and postconditioning have all been shown to be cardioprotective. However, it is still unknown which one is the most beneficial. To examine this issue, we used adult male Wistar rat ischemia reperfusion models to compare the cardioprotective effect of these three approaches applied on double-sided hind limbs. METHODS: The rats were randomly distributed to the following five groups: sham, ischemia reperfusion, remote preconditioning, remote perconditioning, and remote post-conditioning. The ischemia/reperfusion model was established by sternotomy followed by a 30-min ligation of the left coronary artery and a subsequent 3-h reperfusion. Remote conditioning was induced with three 5-min ischemia/5-min reperfusion cycles of the double-sided hind limbs using a tourniquet. RESULTS: A lower early reperfusion arrhythmia score (1.50 + 0.97) was found in the rats treated with remote perconditioning compared to those in the ischemia reperfusion group (2.33 + 0.71). Meanwhile, reduced infarct size was also observed (15.27 + 5.19% in remote perconditioning, 14.53 + 3.45% in remote preconditioning, and 19.84+5.85% in remote post-conditioning vs. 34.47 + 7.13% in ischemia reperfusion, p<0.05), as well as higher expression levels of the apoptosis-relevant protein Bcl-2/Bax following global (ischemia/reperfusion) injury in in vivo rat heart models (1.255 + 0.053 in remote perconditioning, 1.463 + 0.290 in remote preconditioning, and 1.461 +0.541 in remote post-conditioning vs. 1.003 + 0.159 in ischemia reperfusion, p<0.05). CONCLUSION: Three remote conditioning strategies implemented with episodes of double-sided hind limb ischemia/reperfusion have similar therapeutic potential for cardiac ischemia/reperfusion injury, and remote perconditioning has a greater ability to prevent reperfusion arrhythmia.


Subject(s)
Animals , Male , Rats , Ischemic Preconditioning, Myocardial/methods , Myocardial Reperfusion Injury/therapy , Arrhythmias, Cardiac/physiopathology , Myocardial Infarction/prevention & control , Random Allocation , Rats, Wistar , Time Factors , Treatment Outcome , Ventricular Function/physiology
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