Intracellular Calcium Spikes in Rat Suprachiasmatic Nucleus Neurons Induced by BAPTA-Based Calcium Dyes

Background: Circadian rhythms in spontaneous action potential (AP) firing frequencies and in cytosolic free calcium concentrations have been reported for mammalian circadian pacemaker neurons located within the hypothalamic suprachiasmatic nucleus (SCN). Also reported is the existence of "Ca2+ spikes" (i.e., [Ca2+]c transients having a bandwidth of 10～100 seconds) in SCN neurons, but it is unclear if these SCN Ca2+ spikes are related to the slow circadian rhythms. Methodology/Principal Findings: We addressed this issue based on a Ca2+ indicator dye (fluo-4) and a protein Ca2+ sensor (yellow cameleon). Using fluo-4 AM dye, we found spontaneous Ca2+ spikes in 18% of rat SCN cells in acute brain slices, but the Ca2+ spiking frequencies showed no day/night variation. We repeated the same experiments with rat (and mouse) SCN slice cultures that expressed yellow cameleon genes for a number of different circadian phases and, surprisingly, spontaneous Ca2+ spike was barely observed (<3%). When fluo-4 AM or BAPTA-AM was loaded in addition to the cameleon-expressing SCN cultures, however, the number of cells exhibiting Ca2+ spikes was increased to 13～14%. Conclusions/Significance: Despite our extensive set of experiments, no evidence of a circadian rhythm was found in the spontaneous Ca2+ spiking activity of SCN. Furthermore, our study strongly suggests that the spontaneous Ca2+ spiking activity is caused by the Ca2+ chelating effect of the BAPTA-based fluo-4 dye. Therefore, this induced activity seems irrelevant to the intrinsic circadian rhythm of [Ca2+]c in SCN neurons. The problems with BAPTA based dyes are widely known and our study provides a clear case for concern, in particular, for SCN Ca2+ spikes. On the other hand, our study neither invalidates the use of these dyes as a whole, nor undermines the potential role of SCN Ca2+ spikes in the function of SCN

Bare-metal stents versus drug-eluting stents in large (≥3.5mm) single coronary artery: Angiographic and clinical outcomes at 6 months

SummaryBackgroundAlthough drug-eluting stents (DES) have been shown to dramatically reduce restenosis and improve the rate of event-free survival in large randomized trials, the benefit of DES appears to be limited to restenosis. In large arteries, it is not clear which type of stent is more superior in angiographic and clinical outcomes between DES and bare-metal stents (BMS). We compared the angiographic and clinical outcomes of DES versus BMS in large arteries (≥3.5mm).MethodTwo hundred and forty patients from March 2002 to March 2007 received stents; 196 patients were treated with DES (44.9% sirolimus-eluting stents; 43.9% paclitaxel-eluting stents; 11.2% zotarolimus-eluting stents) and 44 with cobalt–chromium BMS for single de novo lesions in a large vessel. All subjects received aspirin, clopidogrel, and/or cilostazol as the standard antiplatelet regimen. The angiographic and clinical outcomes were evaluated at 6 months.ResultsFor the baseline characteristics, there were no significant differences between the DES and BMS groups. In addition, for the initially implanted stent there was no difference in the length, stent diameter, and lesion site between the two groups. After 6 months, the follow-up angiogram showed that in-stent diameter restenosis and late loss was more common with BMS than DES (39±21% vs. 19±17%, p=0.007; 1.44±0.83mm vs. 0.62±0.58mm, p=0.009, respectively). However, the target-lesion revascularization/target-vessel revascularization, and total major adverse cardiac events showed no significant differences between the groups (5.3% vs. 3.6%, p=0.62; 5.3% vs. 4.6%, p=0.86, respectively).ConclusionThe DES and cobalt–chromium BMS placed in large coronary arteries showed equally favorable 6-month clinical outcomes, although the 6-month angiographic results appeared more favorable in the DES group than in the BMS group

Manumycin from a new Streptomyces strain shows antagonistic effect against methicillin-resistant Staphylococcus aureus (MRSA)/vancomycin-resistant enterococci (VRE) strains from Korean Hospitals

An antimicrobial compound, highly effective against multidrug-resistant (MDR) bacteria, purified from a Streptomyces strain was identified as manumycin. The minimal inhibitory concentrations (MICs) of manumycin against 8 different strains of methicillin-resistant Staphylococcus aureus (MRSA) were ranged 2 to 32 μg/ml. Similarly, MICs of manumycin against 4 vancomycin-resistant enterococci (VRE) strains were ranged 8 to 32 μg/ml while it remained ineffective against 4 other VRE strains. Compared to vancomycin, manumycin provided slightly weaker activity against MRSA strains but stronger activity against 4 VRE strains. This is the first report of antagonistic effect of manumycin against MDR pathogens.Keywords: Manumycin, methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE)African Journal of Biotechnology Vol. 12(17), pp. 2249-225

A Prospective, Randomized, 6-Month Comparison of the Coronary Vasomotor Response Associated With a Zotarolimus- Versus a Sirolimus-Eluting Stent Differential Recovery of Coronary Endothelial Dysfunction

ObjectivesWe prospectively compared coronary endothelial dysfunction in patients with zotarolimus-eluting stent (ZES) versus sirolimus-eluting stent (SES) implantation at 6-month follow-up.BackgroundA ZES has been associated with uniform and rapid healing of the endothelium.MethodsFifty patients were randomly treated with intravascular ultrasound-guided stenting with a single stent to the mid-segment of the left anterior descending artery (20 ZES, 20 SES, and 10 bare-metal stents), and endothelial function was estimated before and after intervention at 6-month follow-up by incremental acetylcholine (Ach) (10, 20, 50, and 100 μg/min) and nitrate (200 μg/min) infusions into the left coronary ostium. The vascular response was quantitatively measured in the 5-mm segments proximal and distal to the stent.ResultsIn the drug-eluting stent groups, more intense vasoconstriction to incremental doses of Ach was observed at 6-month follow-up compared with the responses before stenting. Endothelial function associated with the ZES was more preserved at 6-month follow-up compared with the SES. Vasoconstriction to Ach was more prominent in the distal segments than the proximal segments in both the ZES and SES groups. Endothelium-independent vasodilation to nitrate did not differ significantly among the study groups.ConclusionsVasoconstriction in response to Ach in the peri-stent region was less pronounced in the ZES group than the SES group at 6-month follow-up, which suggests that endothelial function associated with ZES can be more preserved than the SES

Six-Month Comparison of Coronary Endothelial Dysfunction Associated With Sirolimus-Eluting Stent Versus Paclitaxel-Eluting Stent

ObjectivesThis study was designed to investigate whether endothelial dysfunction is related to drug-eluting stent (DES) implantation at 6 months after stenting.BackgroundCurrent available DES could delay vessel healing and subsequently impair endothelial function.MethodsEndothelial function was estimated at 6-month follow-up in 75 patients (31 men, mean age 62.1 years) with a DES (39 sirolimus-eluting stents [SES], 36 paclitaxel-eluting stents [PES]), and 10 patients with a bare-metal stent (BMS) to the left anterior descending artery, by incremental acetylcholine (Ach) infusion (20 μg/min, 50 μg/min, 100 μg/min) and nitrate (200 μg/min) into the left coronary ostium. Vascular responses were quantitatively measured in arterial segments 5 mm proximal and distal to DES and compared with corresponding segments in the BMS group and midsegments in the left circumflex artery as a reference nonstented artery. All antianginal agents were withheld for at least 72 h before coronary angiography.ResultsGreater vasoconstriction to Ach was observed in both the SES and PES groups than in the BMS group or control segments of left circumflex artery. Vasoconstriction to Ach was more prominent in arterial segments distal to stents in both SES and PES groups compared with those in the BMS group (p &lt; 0.001). The degree of vasoconstriction to Ach was similar between the SES and PES groups. Endothelium-independent vasodilatation to nitrate did not differ significantly between the study groups.ConclusionsAbnormal vasoconstriction to Ach was found in the SES and PES groups, especially in arterial segments distal to DES at 6 months after stenting, which suggests that DES has a potential long-term adverse effect on local coronary endothelial dysfunction

Comparison of infarct-related artery vs multivessel revascularization in ST-segment elevation myocardial infarction with multivessel disease: Analysis from Korea Acute Myocardial Infarction Registry

Background: Many ST-segment elevation myocardial infarction (STEMI) patients have multivessel disease. There is still controversy in treatment strategy in STEMI patients with multivessel disease. We compared clinical outcomes of multivessel revascularization with infarct- related artery (IRA) revascularization in STEMI patients. Methods: The 1,644 STEMI patients with multivessel disease (1,106 in IRA group, 538 in multivessel group) who were received primary percutaneous coronary intervention (PCI) were analyzed from a nationwide Korea Acute Myocardial Infarction Registry. Primary endpoint was 12-month major adverse cardiac events (MACE, defined as death, myocardial infarction, and repeated revascularization). Secondary endpoints were 1-month MACE and each component, stent thrombosis during 12 month follow-up, and each components of the 12-month MACE. Results: There were more patients with unfavorable baseline conditions in IRA group. 12-month MACE occurred in 165 (14.9%) patients in IRA group, 81 (15.1%) patients in multivessel group (p = 0.953). There were no statistical significance in the rate of 1-month MACE, each components of 1-month MACE, and stent thrombosis during 12 month follow-up. Each components of 12-month MACE were occurred similarly in both groups except for target lesion revascularization (2.4% in IRA group vs 5.9% in multivessel group, p < 0.0001). After adjusting for confounding factors, multivessel revascularization was not associated with reduced 12-month MACE (OR 1.096, 95% CI 0.676&#8211;1.775, p = 0.711). Conclusions: There were no significant differences in clinical outcomes between both groups except for high risk of target lesion revascularization in multivessel revascularization group

Anti-lipoapoptotic effect of Artemisia capillaris extract on free fatty acids-induced HepG2 cells

BACKGROUND: Artemisia capillaris (AC) has been recognized as one of the promising candidates for hepatoprotective, hypoglycemic, hypolipidemic, antiobesitic and anti-inflammatory therapeutic effectiveness. This study evaluated the inherent mechanism and anti-apoptotic activity of 30% ethanol extract of AC (AC extract) 100 μg/ml on free fatty acids (FFAs)-induced HepG2 cellular steatosis and lipoapoptosis. METHODS: Hepatic steatosis was induced by culturing HepG2 cells with a FFAs mixture (oleic and palmitic acid at the proportion of 2:1) for 24 h, thus ultimately giving rise to lipoapoptosis. Cell viability and lipid accumulation were detected by MTT assay and Oil Red O staining method respectively and Caspase-3, −9, Bax, Bcl-2, p-JNK and PUMA were measured for lipoapoptosis after 24 hours. RESULTS: AC extract significantly improved the FFAs-induced steatosis without cytotoxicity and Caspase-3, −9, Bax and Bcl-2 were modulated profitably to HepG2 cells after AC treatment. In addition, AC extract inhibited the activation of c-Jun NH(2) terminal kinase (JNK) and PUMA, which mechanism is related to non-alcoholic steatohepatitis (NASH). CONCLUSIONS: Combined together, AC extract exerted an obvious hypolipidemic and anti-apoptotic effect, indicating that AC extract might have potential therapeutic herb against NASH

Two levels above and one level below pedicle screw fixation for the treatment of unstable thoracolumbar fracture with partial or intact neurology

<p>Abstract</p> <p>Background</p> <p>Treatment of unstable thoracolumbar fractures is controversial regarding short or long segment pedicle screw fixation. Although long level fixation is better, it can decrease one motion segment distally, thus increasing load to lower discs.</p> <p>Methods</p> <p>We retrospectively analyzed 31 unstable thoracolumbar fractures with partial or intact neurology. All patients were operated with posterior approach using pedicle screws fixed two levels above and one level below the fracture vertebra. No laminectomy, discectomy or decompression procedure was done. Posterior fusion was achieved in all. Post operative and at final follow-up radiological evaluation was done by measuring the correction and maintenance of kyphotic angle at thoracolumbar junction. Complications were also reported including implant failure.</p> <p>Results</p> <p>Average follow-up was 34 months. All patients had full recovery at final follow-up. Average kyphosis was improved from 26.7° to 4.1° postoperatively and to 6.3° at final follow-up. And mean pain scale was improved from 7.5 to 3.9 postoperatively and to 1.6 at final follow-up, All patients resumed their activity within six months. Only 4 (12%) complications were noted including only one hardware failure.</p> <p>Conclusion</p> <p>Two levels above and one level below pedicle screw fixation in unstable thoracolumbar burst fracture is useful to prevent progressive kyphosis and preserves one motion segment distally.</p

Protective effects of Scutellaria baicalensis Georgi against hydrogen peroxide-induced DNA damage and apoptosis in HaCaT human skin keratinocytes

Oxidative stress due to excessive accumulation of reactive oxygen species (ROS) is one of the risk factors for the development of several chronic diseases. In this study, we investigated the protective effects of Scutellaria bai- calensis rhizome ethanol extract (SBRE) against oxidative stress-induced cellular damage and elucidated the un- derlying mechanisms in the HaCaT human skin keratinocyte cell line. Our results revealed that treatment with SBRE prior to hydrogen peroxide (H2O2) exposure significantly increased viability of aCaT cells. SBRE also effectively attenuated H2O2-induced comet tail formation and inhibited the H2O2-induced phosphorylation levels of the histone γH2AX, as well as the number of apoptotic bodies and Annexin V-positive cells. In addition, SBRE exhibited scavenging activity against intracellular ROS generation and restored the mitochondrial membrane po- tential loss by H2O2. Moreover, H2O2 enhanced the cleavage of caspase-3 and degradation of poly (ADP-ribose)- polymerase, a typical substrate protein of activated caspase-3, as well as DNA fragmentation; however, these events were almost totally reversed by pretreatment with SBRE. Furthermore, SBRE increased the levels of heme oxygenase-1 (HO-1), which is a potent antioxidant enzyme, associated with the induction of nuclear fac- tor-erythroid 2-related factor 2 (Nrf2). According to our data, SBRE is able to protect HaCaT cells from H2O2- induced DNA damage and apoptosis through blocking cellular damage related to oxidative stress through a mech-anism that would affect ROS elimination and activating the Nrf2/HO-1 signaling pathway