Protective effect of 5, 7-dihydroxyflavone on brain of rats exposed to acrylamide or γ-radiation

5, 7-Dihydroxyflavone (DHF), a natural plant flavonoid, have shown a variety of beneficial effects. Neurotoxic effects of acrylamide (ACR) or gamma irradiation (IR) have been established in humans and animals. The current study was designed to evaluate whether DHF could restrain ACR or IR induced neurotoxicity in rats and to explore the underlying mechanisms. The study was carried out by investigating some biochemical and biophysical parameters as well as histopathological examination. The daily oral administration of ACR (25mg/kg b.wt.) for 21days or exposure to single dose of IR (5Gy) induced brain damage throughout the significant decrease in catecholamine contents and brain derived neurotrophic factor (BDNF) in brain tissue with a concomitant significant decrease in serum activity of creatinine kinase-BB. Moreover, the brain levels of MDA and β-amyloid and activities of acetylcholinesterase and caspase-3 were remarkably augmented in ACR-induced rats. Additionally, the electrical properties of erythrocytes membrane were significantly disturbed. The administration of DHF (50mg/kg b.wt. daily for 21day) to rats exposed to either ACR or IR significantly reversed the alteration in all studied parameters. Histopathological investigation of brain tissues supported the neuroprotective effect of DHF on brain. From the obtained data, it can be concluded that the DHF has neuroprotective effect against ACR or IR induced-neurotoxicity.

[Update regarding the role of biomarkers in early diagnosis of non-small cell bronchopulmonary cancer]

Early diagnosis of lung cancer by non-invasive methods has a low sensibility: 60% of peripheral cancers could be diagnosed by computed tomography, 60% of the central ones by sputum cytology. More specific for detecting central microinvasive lesions could be bronchoscopy with autofluorescence, but this is a method with a low number of patients to be performed on, because of the specific technique. For all these reasons there are some other methods to be tried in this respect--one of them is to find one or more molecules--tumoral markers--which have to be specific in establishing the risk of developing lung cancer, to make an early diagnosis of cancer and to predict the evolution under treatment. The detecting tumoral markers in sputum, blood, bronchoalveolar lavage was not so largely explored related to the final goal--the possibility of identifying and quantifying the most specific ones for the screening of lung cancer. The present paper has as purpose to make an review of tumoral markers--"classical" markers as: CEA, NSE, TPA, beta2 microglobulina, CA 125, CA 15-3--considered not such a high sensibility and specificity for lung cancer screening versus new molecules, studied intensively as: SCC-Ag, CYFRA 21-1, ferritin, sIL-2R, CCK-BB, glycosyltransferases. Those new molecules have a higher sensibility, but also could have a higher specificity for each type of lung cancer.

Reduced creatine kinase as a central and peripheral biomarker in Huntington's disease

A major goal of current clinical research in Huntington's disease (HD) has been to identify preclinical and manifest disease biomarkers, as these may improve both diagnosis and the power for therapeutic trials. Although the underlying biochemical alterations and the mechanisms of neuronal degeneration remain unknown, energy metabolism defects in HD have been chronicled for many years. We report that the brain isoenzyme of creatine kinase (CK-BB), an enzyme important in buffering energy stores, was significantly reduced in presymptomatic and manifest disease in brain and blood buffy coat specimens in HD mice and HD patients. Brain CK-BB levels were significantly reduced in R6/2 mice by approximately 18% to approximately 68% from 21 to 91 days of age, while blood CK-BB levels were decreased by approximately 14% to approximately 44% during the same disease duration. Similar findings in CK-BB levels were observed in the 140 CAG mice from 4 to 12 months of age, but not at the earliest time point, 2 months of age. Consistent with the HD mice, there was a grade-dependent loss of brain CK-BB that worsened with disease severity in HD patients from approximately 28% to approximately 63%, as compared to non-diseased control patients. In addition, CK-BB blood buffy coat levels were significantly reduced in both premanifest and symptomatic HD patients by approximately 23% and approximately 39%, respectively. The correlation of CK-BB as a disease biomarker in both CNS and peripheral tissues from HD mice and HD patients may provide a powerful means to assess disease progression and to predict the potential magnitude of therapeutic benefit in this disorder.

[Safety of early cardiac magnetic resonance imaging in acute myocardial infarction patients with stents]

INTRODUCTION AND OBJECTIVES

In general, magnetic resonance imaging is contraindicated when the patient has a ferromagnetic prosthesis or implant. With coronary stents, there is a theoretical concern that use of magnetic resonance imaging shortly after implantation will dislodge the stent, thereby increasing the risk of thrombosis. However, the risk may be overestimated because modern coronary stents are not ferromagnetic or are only weakly so. The objective of this study was to determine whether carrying out cardiac magnetic resonance imaging shortly after stent implantation is a safe procedure in acute myocardial infarction patients.

METHODS

We carried out a retrospective study of 407 patients with ST-elevation acute myocardial infarction who were treated by stent implantation. Cardiac magnetic resonance imaging was performed in the first 14 (11) days after stent implantation in 86 of these 407 patients (group 1); it was not performed in the 321 patients in group 2. The occurrence of an adverse event, such as death, reinfarction, or revascularization, either in hospital or after 6 or 12 months was recorded.

RESULTS

Three patients experienced subacute stent thrombosis, all in group 2. No statistically significant difference in any other variable was found. The combined rate of death, reinfarction, revascularization, or rehospitalization at 12 months was 14% in group 1 and 16% in group 2 (P=.7).

CONCLUSIONS

Carrying out cardiac magnetic resonance imaging shortly after stent implantation in acute myocardial infarction patients appears to be a safe procedure.

Proteasome inhibition attenuates lung injury induced by intestinal ischemia reperfusion in rats

The aim of this study is to investigate the role of proteasome in the pathogenesis of lung injury induced by intestinal ischemia/reperfusion (I/R) by examining the effect of the proteasome inhibitor lactacystin on neutrophil infiltration, intracellular adhesion molecule-1 (ICAM-1) expression and nuclear factor kappa B (NF-kappaB) activation. Thirty-two Wistar rats were divided into (1) control, (2) intestinal I/R, (3) 0.2 mg/kg lactacystin pretreated, and (4) 0.6 mg/kg lactacystin pretreated groups (n=8). Injuries in lung and intestine were induced by intestinal I/R, and were characterized by histological edema, hemorrhage and infiltration of inflammatory cells. The results showed a significant increase in serum creatine kinase B (CK-B) and lung water content in intestine and lung injuries. As compared with the control group, the myeloperoxidase (MPO) activity in intestine and lung as well as the serum TNF-alpha level increased significantly in intestinal I/R group. Simultaneously, expression of ICAM-1 and NF-kappaB p65 was also observed in the I/R group. Pre-treatment with lactacystin markedly reduced 20S proteasome activity in circulating white blood cells and ameliorated intestine and lung injuries. These results demonstrated that the proteasome participates in the pathogenesis of lung injury induced by intestinal I/R. Lactacystin as a proteasome inhibitor can prevent this kind of injury by decreasing ICAM-1 and TNF-alpha production via the inhibition of NF-kappaB activation.

Safety of intramyocardial injection of autologous bone marrow cells to treat myocardial ischemia in pigs

OBJECTIVE

The purpose of this study is to determine the potential adverse consequences of intracardiac injections of bone marrow mononuclear cells (BMCs) to facilitate the revascularization of ischemic myocardium.

BACKGROUND

Bone marrow mononuclear cells are used to treat heart failure, though there are few studies that evaluated the safety of BMC transplantation for chronic myocardial ischemia.

METHODS

The pigs received coronary ameroid constrictors to induce chronic myocardial ischemia and left ventricular dysfunction. At 4 weeks, autologous BMCs were injected intramyocardially by Boston Scientific Stiletto catheter with low-dose (10(7) cells) or high-dose BMC (10(8)). Control animals received saline. Blood samples were collected for hematological and chemical indices, including cardiac enzyme levels at regular time intervals postinfarction. At 7 weeks, animals underwent electrophysiological study to evaluate the arrhythmic potential of transplanted BMC, followed by necropsy and histopathology.

RESULTS

No mortalities were associated with intramyocardial delivery of BMC or saline. At Day 0, the total creatine phosphokinase (CPK) was in the normal range in all groups. All groups had significant elevations in CPK after ameroid placement, with no significant differences between groups. At 7 weeks, CPK in all groups had returned to pretreatment levels. Electrophysiological assessment revealed that one control animal had an inducible arrhythmia. No arrhythmias were induced in low- or high-dose BMC-treated pigs. There were no histopathological changes associated with BMC injection.

CONCLUSION

This study showed, in a clinically relevant large-animal model, that catheter-based intramyocardial injection of autologous BMC into ischemic myocardium is safe.

[Effects of Ginaton on the markers of myocardial injury during cardiopulmonary bypass]

OBJECTIVE

To evaluate the effects of Ginaton (Ginkgo biloba leaf extract) on the myocardial injury markers (MIMs) during cardiopulmonary bypass (CPB).

METHODS

Forty patients with congenital heart diseases, scheduled to take atrial septum or ventricular septum repairing operation, were randomly divided into the Ginaton group and the control group, 20 cases in each group. Patients in both groups received St. Thomas' cardioplegic perfusion via radix aortae, while Ginaton (0.5 mg/kg) was added into the perfusion for the Ginton group. Cardiac surgery were started after complete heart arrest. Central venous blood was obtained before and at 0, 6th, 12th, 24th and 48th hour after operation for detection of serum C reaction protein (CRP) by immunoturbidimetry, as well as creation kinase-MB isoenzyme (CK-MB), cardiac troponin T (cTnT) and cardiac troponin I (cTnI) with enzyme-linked immunosorbent assay (ELISA).

RESULTS

There was no difference in serum concentration of CRP, CK-MB, cTnT and cTnI between the two groups before operation (P > 0.05). These indexes increased immediately after operation in both groups ( P < 0.05). They reached the peak value 12 hrs after CPB and reduced to normal level 48 hrs post-operation in the control group, with the value significantly higher than that in the Ginaton group at all the corresponding time points (P < 0.05, or P < 0.01).

CONCLUSION

Perfusion with Ginaton during CPB could significantly decrease the release of MIMs and improve post-CPB cardiac function recovery, exerting favorable myocardium-protective effects.

Does antegrade cerebral perfusion protect the brain during deep hypothermic circulatory arrest?

PURPOSE

This study compares cerebral protection using no cerebroplegia and using antegrade cerebroplegia with variable flow rates during deep hypothermic circulatory arrest (DHCA).

METHODS

Twenty healthy neonatal piglets (2.5-3.8 kg) underwent 60 minutes of DHCA. No cerebroplegia was used in group 1 (n = 5). Cold (16 degrees C) antegrade cerebral perfusate was administered through the innominate artery at 10 mL/kg per minute in group 2 (n = 5), at 25 mL/kg per minute in group 3 (n = 5), and at 50 mL/kg per minute in group 4 (n = 5). Venous samples for lactate, pyruvate, S-100B protein, and creatine kinase BB (CKBB) were drawn from the jugular vein before and after discontinuation of cardiopulmonary bypass--lactate at 5 minutes postbypass, pyruvate at 5 minutes postbypass, S-100B protein at 30 minutes postbypass, and CKBB at 6 hours postbypass. Piglets were killed 6 hours postbypass and their brains were harvested for histological/immunologic studies. Extent of damage was assessed using a semiquantitative score of 0 to 4 based on a validated method.

RESULTS

Evidence for significant apoptosis and necrosis was apparent in all groups. The mean H&E score was 2.2 for group 1, 2.3 for group 2, 2.5 for group 3, and 2.3 for group 4. The mean terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling score was 1.0 for group 1, 1.2 for group 2, 1.7 for group 3, and 0.8 for group 4. Pathological changes were not greater in the piglets that did not have antegrade cerebral perfusion. Serum lactate, pyruvate, S-100B protein, and CKBB did not distinguish between perfusion strategies.

CONCLUSIONS

In neonates, unmodified antegrade cerebral perfusion at flow rates of 10, 25, and 50 mL/kg per minute during DHCA does not provide additional protection of the brain as determined by histology, immunology, serum lactate, pyruvate, S-100B protein, and CKBB.