Light-sheet autofluorescence lifetime imaging with a single-photon avalanche diode array.

Significance: Fluorescence lifetime imaging microscopy (FLIM) of the metabolic co-enzyme nicotinamide adenine dinucleotide (phosphate) [NAD(P)H] is a popular method to monitor single-cell metabolism within unperturbed, living 3D systems. However, FLIM of NAD(P)H has not been performed in a light-sheet geometry, which is advantageous for rapid imaging of cells within live 3D samples. Aim: We aim to design, validate, and demonstrate a proof-of-concept light-sheet system for NAD(P)H FLIM. Approach: A single-photon avalanche diode camera was integrated into a light-sheet microscope to achieve optical sectioning and limit out-of-focus contributions for NAD(P)H FLIM of single cells. Results: An NAD(P)H light-sheet FLIM system was built and validated with fluorescence lifetime standards and with time-course imaging of metabolic perturbations in pancreas cancer cells with 10 s integration times. NAD(P)H light-sheet FLIM in vivo was demonstrated with live neutrophil imaging in a larval zebrafish tail wound also with 10 s integration times. Finally, the theoretical and practical imaging speeds for NAD(P)H FLIM were compared across laser scanning and light-sheet geometries, indicating a 30× to 6× acquisition speed advantage for the light sheet compared to the laser scanning geometry. Conclusions: FLIM of NAD(P)H is feasible in a light-sheet geometry and is attractive for 3D live cell imaging applications, such as monitoring immune cell metabolism and migration within an organism.

Light sheet autofluorescence lifetime imaging with a single photon avalanche diode array.

Single photon avalanche diode (SPAD) array sensors can increase the imaging speed for fluorescence lifetime imaging microscopy (FLIM) by transitioning from laser scanning to widefield geometries. While a SPAD camera in epi-fluorescence geometry enables widefield FLIM of fluorescently labeled samples, label-free imaging of single-cell autofluorescence is not feasible in an epi-fluorescence geometry because background fluorescence from out-of-focus features masks weak cell autofluorescence and biases lifetime measurements. Here, we address this problem by integrating the SPAD camera in a light sheet illumination geometry to achieve optical sectioning and limit out-of-focus contributions, enabling fast label-free FLIM of single-cell NAD(P)H autofluorescence. The feasibility of this NAD(P)H light sheet FLIM system was confirmed with time-course imaging of metabolic perturbations in pancreas cancer cells with 10 s integration times, and in vivo NAD(P)H light sheet FLIM was demonstrated with live neutrophil imaging in a zebrafish tail wound, also with 10 s integration times. Finally, the theoretical and practical imaging speeds for NAD(P)H FLIM were compared across laser scanning and light sheet geometries, indicating a 30X to 6X frame rate advantage for the light sheet compared to the laser scanning geometry. This light sheet system provides faster frame rates for 3D NAD(P)H FLIM for live cell imaging applications such as monitoring single cell metabolism and immune cell migration throughout an entire living organism.

Polygonum viviparum L. induces vasorelaxation in the rat thoracic aorta via activation of nitric oxide synthase in endothelial cells.

BACKGROUND: In the past several decades, Polygonum viviparum L. (PV) was reported to have antibacterial, antiulcer, antioxidant, antitumor, anti-inflammatory, and antiarthritic properties. The anti-inflammatory pathway was recently elucidated through cytosolic nuclear factor E2-related factor 2 (Nrf2) activation and heme oxygenase (HO)-1 protein expression. PV is a perennial herb and widely distributed in high-elevation mountain regions, such as the Tibetan Plateau. In Tibetan traditional medicine, PV is usually used to boost the blood circulation to dissipate blood stasis. Therefore, this study focused on how PV improves the vascular circulation and acts on vascular tissues. METHODS: In this study, we isolated aortas from Sprague-Dawley rats (male, weight about 250~350 g), and detected the effects of PV on phenylephrine (PE)-induced contraction and cyclic guanosine 3',5'-monophosphate (cGMP) formation using aortic rings. In addition, human umbilical vein endothelial cells (HUVECs) were used to exam nitric oxygen (NO) synthase (NOS) activity by directly measuring NO production in the culture medium. Endothelial (e) NOS phosphorylation, and cytosolic Nrf2 and HO-1 expressions were measured using a Western blot analysis. RESULTS: PV dose-dependently relaxed PE-induced contractions in endothelial-intact but not -denuded aorta. The concentration to produce 50% relaxation was 22.04±1.77 µg/ml. PV-induced vasorelaxation was markedly blocked by pretreatment with NG-nitro-L-arginine methyl ester (L-NAME), an NOS inhibitor, methylene blue (MB), a guanylyl cyclase inhibitor, and hemoglobin, an NO scavenger. PV increased cGMP formation; however, this effect was also suppressed by co-pretreatment with l-NAME, MB, hemoglobin, and Ca2+-free medium. In HUVECs, PV increased NO formation, which was greatly attenuated by NOS inhibitors (L-NAME and L-NMMA) and by removing extracellular Ca2+ and chelating intracellular Ca2+ with BAPTA-AM. In addition, PV promoted eNOS phosphorylation, Nrf2 degradation, and HO-1 protein expression according to a Western blot analysis. CONCLUSIONS: The results suggest that PV possesses vasorelaxing action in an endothelium-dependent manner and works through activating Ca2+/calmodulin- dependent NO synthesis; when NO is released and then transferred to smooth muscle cells, NO activates guanylyl cyclase and increases cGMP formation, ultimately resulting in vasorelaxation. Thus, PV can be considered for application as a potential therapeutic approach for vascular-associated disorders.

Efficacy and safety of IV ferumoxytol for adults with iron deficiency anemia previously unresponsive to or unable to tolerate oral iron.

Although oral iron is the initial treatment approach for iron deficiency anemia (IDA), some patients fail to respond to or cannot tolerate oral iron. This double-blind safety and efficacy study of the intravenous (IV) iron, ferumoxytol, randomized patients with a history of unsatisfactory oral iron therapy, or in whom oral iron could not be used, to ferumoxytol (n = 609) or placebo (n = 203). The proportion of patients achieving the primary endpoint (hemoglobin increase ≥2.0 g/dL at Week 5) was 81.1% with ferumoxytol versus 5.5% with placebo (P < 0.0001). The mean increase in hemoglobin from Baseline to Week 5, a secondary endpoint (also the alternative preplanned primary efficacy endpoint for other health authorities), was 2.7 versus 0.1 g/dL (P < 0.0001). Achievement of a hemoglobin ≥12 g/dL, time to a hemoglobin increase ≥2.0 g/dL, and improvement in the Functional Assessment of Chronic Illness Therapy Fatigue score also significantly favored ferumoxytol over placebo at Week 5 (P < 0.0001). Ferumoxytol treatment-emergent adverse events were mainly mild to moderate. Ferumoxytol was effective and well tolerated in patients with IDA of any underlying cause in whom oral iron was ineffective or could not be used. This trial was registered at www.clinicaltrials.gov as #NCT01114139.

Polygonum viviparum L. inhibits the lipopolysaccharide-induced inflammatory response in RAW264.7 macrophages through haem oxygenase-1 induction and activation of the Nrf2 pathway.

BACKGROUND: Polygonum viviparum L. (PV) is a member of the family Polygonaceae and is widely distributed in high-elevation areas. It is used as a folk remedy to treat inflammation-related diseases. This study was focused on the anti-inflammatory response of PV against lipopolysaccharide (LPS)-induced inflammation in RAW264.7 macrophages. RESULTS: Treatment with PV did not cause cytotoxicity at 0-50 µg mL(-1) in RAW264.7 macrophages, and the IC(50) value was 270 µg mL(-1). PV inhibited LPS-stimulated nitric oxide (NO), prostaglandin (PG)E(2) , interleukin (IL)-1ß and tumour necrosis factor (TNF)-α release and inducible NO synthase (iNOS) and cyclooxygenase (COX)-2 protein expression. In addition, PV suppressed the LPS-induced p65 expression of nuclear factor (NF)-κB, which is associated with the inhibition of IκB-α degradation. These results suggest that, among mechanisms of the anti-inflammatory response, PV inhibits the production of NO and these cytokines by down-regulating iNOS and COX-2 gene expression. Furthermore, PV can induce haem oxygenase (HO)-1 protein expression through nuclear factor E2-related factor 2 (Nrf2) activation. A specific inhibitor of HO-1, zinc(II) protoporphyrin IX, inhibited the suppression of iNOS and COX-2 expression by PV. CONCLUSION: These results suggest that PV possesses anti-inflammatory actions in macrophages and works through a novel mechanism involving Nrf2 actions and HO-1. Thus PV could be considered for application as a potential therapeutic approach for inflammation-associated disorders.

Protective effect of guggulsterone against cardiomyocyte injury induced by doxorubicin in vitro.

BACKGROUND: Doxorubicin (DOX) is an effective antineoplastic drug; however, clinical use of DOX is limited by its dose-dependent cardiotoxicity. It is well known that reactive oxygen species (ROS) play a vital role in the pathological process of DOX-induced cardiotoxicity. For this study, we evaluated the protective effects of guggulsterone (GS), a steroid obtained from myrrh, to determine its preliminary mechanisms in defending against DOX-induced cytotoxicity in H9C2 cells. METHODS: In this study, we used a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay, lactate dehydrogenase (LDH) release measurements, and Hoechst 33258 staining to evaluate the protective effect of GS against DOX-induced cytotoxicity in H9C2 cells. In addition, we observed the immunofluorescence of intracellular ROS and measured lipid peroxidation, caspase-3 activity, and apoptosis-related proteins by using Western blotting. RESULTS: The MTT assay and LDH release showed that treatment using GS (1-30 µM) did not cause cytotoxicity. Furthermore, GS inhibited DOX (1 µM)-induced cytotoxicity in a concentration-dependent manner. Hoechst 33258 staining showed that GS significantly reduced DOX-induced apoptosis and cell death. Using GS at a dose of 10-30 µM significantly reduced intracellular ROS and the formation of MDA in the supernatant of DOX-treated H9C2 cells and suppressed caspase-3 activity to reference levels. In immunoblot analysis, pretreatment using GS significantly reversed DOX-induced decrease of PARP, caspase-3 and bcl-2, and increase of bax, cytochrome C release, cleaved-PARP and cleaved-caspase-3. In addition, the properties of DOX-induced cancer cell (DLD-1 cells) death did not interfere when combined GS and DOX. CONCLUSION: These data provide considerable evidence that GS could serve as a novel cardioprotective agent against DOX-induced cardiotoxicity.

Effect of Sanguis draconis (a dragon's blood resin) on streptozotocin- and cytokine-induced ß-cell damage, in vitro and in vivo.

The study was to examine the effects of Sanguis draconis ethanol extract (SDEE) on streptozotocin (STZ)- and cytokine-induced ß-cell damage. In vitro, SDEE did not cause cytotoxicity below 200 µg/ml, and can prevent STZ (5mM)-induced cell death and apoptosis below 100 µg/ml on RIN-m5F cells. SDEE inhibits IL-1ß/IFN-γ-stimulated NO, TNF-α release, and iNOS expression. Furthermore, SDEE suppressed the IL-1ß/IFN-γ- or STZ-induced p65 expression of NF-κB, which is associated with inhibition of IκB-α degradation. In vivo, treatment of ICR mice with STZ (100 mg/kg, i.p. single injection) resulted in hyperglycemia and hypoinsulinemia, which was further evidenced by blood glucose and plasma insulin. The diabetogenic effects of STZ were completely prevented when mice were orally administered with SDEE for 3 weeks, however, the blood glucose and plasma insulin showed no significant change after SDEE administration alone. In addition, SDEE also can inhibit STZ-induced iNOS protein expression, pancreatic injury and lipid peroxidation. In conclusions, the molecular mechanism by which SDEE inhibits iNOS gene expression appears to involve the inhibition of NF-κB activation. These results suggest the possible therapeutic value of S. draconis and could be potentially developed into a novel drug for preventing the progression of diabetes mellitus.

Myrrh mediates haem oxygenase-1 expression to suppress the lipopolysaccharide-induced inflammatory response in RAW264.7 macrophages.

OBJECTIVES: To elucidate a novel anti-inflammatory mechanism of myrrh against lipopolysaccharide (LPS)-induced inflammation. METHODS: RAW264.7 macrophages were cultured in DMEM and then cells were treated with LPS or LPS plus a myrrh methanol extract (MME) for 24h. The culture medium was collected for determination of nitric oxide (NO), prostaglandin (PG)E(2) , interleukin (IL)-1ß, and tumour necrosis factor (TNF)-α, and cells were harvested by lysis buffer for Western blot analysis. KEY FINDINGS: Our data showed that treatment with the MME (1∼100µg/ml) did not cause cytotoxicity or activate haem oxygenase-1 (HO-1) protein synthesis in RAW264.7 macrophages. Furthermore, the MME inhibited LPS-stimulated NO, PGE(2) , IL-1ß and TNF-α release and inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 protein expression. Zn(II) protoporphyrin IX, a specific inhibitor of HO-1, blocked the inhibition of iNOS and COX-2 expression by the MME. CONCLUSIONS: These results suggest that among mechanisms of the anti-inflammatory response, the MME inhibited the production of NO, PGE(2) , IL-1ß and TNF-α by downregulating iNOS and COX-2 gene expression in macrophages and worked through the action of HO-1.

Protective effect of dried safflower petal aqueous extract and its main constituent, carthamus yellow, against lipopolysaccharide-induced inflammation in RAW264.7 macrophages.

BACKGROUND: Safflower, whose botanic name is Carthamus tinctorius L., is a member of the family Compositae or Asteraceae. Carthamus yellow (CY) is the main constituent of safflower and is composed of safflomin A and safflomin B. Dried safflower petals are used in folk medicine and have been shown to invigorate blood circulation, break up blood stasis, and promote menstruation. In addition, dried safflower petals contain yellow dyes that are used to color food and cosmetics. In this study, we investigated the effects of dried safflower petals aqueous extracts (SFA) and CY on lipopolysaccharide (LPS)-induced inflammation using RAW264.7 macrophages. RESULTS: Our data showed that treatment with SFA (1-1000 microg mL(-1)) and CY (1-2000 microg mL(-1)) does not cause cytotoxicity in cells. SFA and CY inhibited LPS-stimulated nitric oxide (NO), prostaglandin E(2) (PGE(2)), and interleukin 1ß (IL-1ß) release, through attenuation of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) protein expression. Further, SFA and CY suppressed the LPS-induced phosphorylation of nuclear factor-κB, which was associated with the inhibition of IκB-α degradation. CONCLUSION: These results suggest that SFA and CY provide an anti-inflammatory response through inhibiting the production of NO and PGE(2) by the downregulation of iNOS and COX-2 gene expression. Thus safflower petals have the potential to provide a therapeutic approach to inflammation-associated disorders.

Characteristics of bicycle-related head injuries among school-aged children in Taipei area.

BACKGROUND: Bicycle-related head injury is an important public health issue. A paucity of statistical data on bicycle accidents exists in Taiwan. The purpose of this study was to report the characteristics of bicycle-related head injuries among school-aged children in Taipei, Taiwan. METHODS: Between 2001 and 2002, basic patient information of those with bicycle-related head injuries was collected from the Trauma Data Registry in 5 hospitals of the Taipei area. Telephone interviews were conducted to collect specific information surrounding bicycle accidents. RESULTS: Of 324 patients with bicycle-related head injuries, 90 (27.8%) had severe head injuries. Boys compared with girls had a higher proportion of severe head injuries (34.1% vs 23.4%; P = .048). Children aged 5 to 9 years had a higher proportion of severe head injuries compared with ages 10 to 14 years (65.2% vs 6.4%; P = .043). Bicycles without reflectors had a higher proportion of severe head injuries compared to bicycles with reflectors (69.0% vs 5.7%; P = .004). Bicyclists carrying goods (such as backpacks or weighted toward the road) and speeding were associated with severe head injury (P < .05). Collisions with vehicles of a larger size resulted in a higher rate of severe head injury compared with collisions with pedestrians (76.9% vs 3.6%; P = .043). CONCLUSIONS: For children whose main mode of transport is bicycles, the enforcement of helmet legislation, educational programs in bicycling safety and equipment, and improving the infrastructure for bicycling in urban areas are needed in Taiwan to reduce potentially debilitating or life-threatening injuries.

Pancreatic tail pseudocyst associated with spontaneous resolution of intrasplenic pancreatic pseudocyst.

A 27-year-old man, an alcohol abuser, had alcoholic pancreatitis complicated by a 3.2 cm pancreatic tail speudocyst and intrasplenic pseudocysts presenting with left upper quadrant pain of one-month duration. Surgical resection or percutaneous drainage of the cystic lesions of the pancreas and the spleen was refused. Analgesic agents were given for relief of abdominal pain. Three months later, another episode of alcoholic pancreatitis occurred. A computed axial tomographic scans of the abdomen showed diffuse enlargement of the pancreas with a 3.0-cm pseudocyst in the pancreatic tail, but there was no evidence of previous intrasplenic pseudocysts. The patient was treated conservatively and was discharged on the 7th hospital day. There was no recurrence of abdominal pain after 3 months follow-up.

Effect of schisandrin B and sesamin mixture on CCl(4)-induced hepatic oxidative stress in rats.

To study the effects of schisandrin B and sesamin mixture on carbon tetrachloride (CCl(4))-induced hepatic oxidative stress in male Sprague-Dawley rats. The rats were randomly assigned to five groups: control group (olive oil injection), CCl(4) group (CCl(4) injection), silymarin group (CCl(4) injection combined with supplementation of silymarin, 7.5 mg/kg/day), low dose group (CCl(4) injection combined with supplementation of schisandrin B and sesamin mixture at a low dose, 43 mg/kg/day) and high dose group (CCl(4) injection combined with the supplementation of schisandrin B and sesamin mixture at a high dose, 215 mg/kg/day). The hepatic superoxide dismutase and glutathione peroxidase activities of rats in the low dose and high dose groups were increased significantly compared with those in the CCl(4) group. The hepatic reduced glutathione concentration in the silymarin, low dose and high dose groups were increased significantly (48%, 45% and 53%, respectively) when compared with those of the CCl(4) group. In addition, the concentration of glutathione in the erythrocytes of the low dose group was significantly higher than the CCl(4) group by 25%. These results suggest that the schisandrin B-sesamin mixture exerted a hepatoprotective effect by improving the antioxidative capacity in rats under CCl(4)-induced hepatic oxidative stress.

Heme oxygenase-1 mediates the inhibitory actions of brazilin in RAW264.7 macrophages stimulated with lipopolysaccharide.

Brazilin, the main constituent of Caesalpinia sappan L., is a natural red pigment that has been reported to possess anti-inflammatory properties. This study aimed to identify a novel anti-inflammatory mechanism of brazilin. We found that brazilin did not cause cytotoxicity below 300 microM, and activated heme oxygenase-1 (HO-1) protein synthesis in a concentration-dependent manner at 10-300 microM in RAW264.7 macrophages without affecting mRNA transcription of HO-1. Additionally, brazilin increased bilirubin production and HO-1 activity in RAW264.7 macrophages. In lipopolysaccharide (LPS)-stimulated macrophages, brazilin suppressed the release of nitric oxide (NO), prostaglandin E(2) (PGE(2)), interleukin (IL)-1beta and tumor necrosis factor-alpha (TNF-alpha), and reduced the expression of inducible nitric oxide synthase (iNOS). A specific inhibitor of HO-1, Zn(II) protoporphyrin IX, blocked the suppression of NO production, cytokines release and iNOS expression by brazilin. These results suggest that brazilin possesses anti-inflammatory actions in macrophages and works through a novel mechanism involving the action of HO-1.

Induction of hepatotoxicity by sanguinarine is associated with oxidation of protein thiols and disturbance of mitochondrial respiration.

Sanguinarine (SANG) has been suggested to be one of the principle constituents responsible for the toxicity of Argemone mexicana seed oil. In this study, we focused on the possible mechanism of SANG-induced hepatotoxicity. The serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH) activities, hepatic vacuolization, lipid accumulation and lipid peroxidation of the liver were increased, and triglyceride (TG) was decreased in SANG-treated mice (10 mg kg(-1) i.p.), indicating damage to the liver. SANG induced cell death and DNA fragmentation, in a concentration- (0-30 microm) and time-dependent (0-24 h) manner, and the cytotoxicity of SANG (15 microm) was accompanied by an increase in reactive oxygen species and a lessening in protein thiol content; these outcomes were reversed by glutathione, N-acetyl-l-cysteine and 1,4-dithiothretol, and slightly improved by other antioxidants in hepatocytes. SANG can affect the function of mitochondria, leading to the depletion of the mitochondrial membrane potential and adenosine 5'-triphosphate content of hepatocytes. SANG caused an uncoupling effect of the respiratory chain at lower concentrations, but inhibited the respiratory chain at higher concentrations in mitochondria isolated from rat liver. In conclusion, the data suggest that SANG is a liver toxin that induces cytotoxicity in liver cells, possibly through oxidation of protein thiols, resulting in oxidative stress on the cells and disturbance of mitochondrial function.