Investigation of the extended focusing capability of the spherical aberration to enlarge the field of view in light-sheet fluorescence microscopy.

In light-sheet fluorescence microscopy (LSFM), using Gaussian beams for light-sheet generation results in a trade-off between the thickness and the field of view (FOV). Here we present a theoretical analysis of using spherical aberration to enlarge the FOV while keeping the light-sheet thickness small. Such spherical aberration can arise when focusing beams through an interface between materials of mismatched refractive indices. The depth-of-focus extension of the Gaussian beam is achieved when using air objectives to focus light into the samples dipped in the immersion medium with a higher refractive index. By scanning this elongated beam, a thin light sheet with a wide FOV can be used for LSFM imaging. Meanwhile, the accompanied sidelobes with the spherical aberrated light sheet, which are mainly distributed in the rear part of the light sheet, are also discussed. Simulation results show that an extended FOV of 64.4µm is possible for an objective lens of NA=0.3, which is about 5 times that of the unaberrated case. For such an extended FOV, a comparatively thin thickness of 1.38µm as well as the first sidelobe about 11.1% of the peak intensity in the center are also demonstrated.

Pharmacokinetic comparative study of GAS with different concentration of tetramethylpyrazine and ferulic acid on liver-yang hyperactivity migraine model by blood-brain microdialysis method.

Gastrodia elata and Ligusticum chuanxiong are used to treat primary headaches for many years. Gastrodin (GAS) and tetramethylpyrazine (TMP)/ferulic acid (FA) are the main active ingredients of Gastrodia elata and Ligusticum chuanxiong, respectively. Previous studies demonstrated the pharmacokinetics of GAS, TMP, and FA in the blood and brain interstitial fluids (BIF) in healthy animals but not in animal model with liver-yang hyperactivity migraine. Hence, this study examined the pharmacokinetics of GAS after its oral administration in the presence of different concentrations of TMP and FA in animals with liver-yang migraine hyperactivity. In the control group, GAS was administrated without TMP and FA. Pharmacokinetic parameters were determined using the blood-brain microdialysis in combination with the high-performance liquid chromatography method. Results revealed that the maximum drug concentrations (Cmax) in the serum, area under curve (AUC), and mean residence time (MRT) of GAS decreased in normal animals, whereas Cmax increased significantly in model animals. These findings indicate that varying concentrations of TMP and FA play an important role in the pharmacokinetics of GAS in both normal and migraine model animals, validating the utility of the ancient formulation.

Subtraction method via phase mask enables contrast enhancement in scanned Bessel light-sheet microscopy.

We report on the generation of a hollow Bessel beam with a hole along the direction of propagation by using an easy-to-implement phase mask and investigate its effectiveness to reduce the out-of-focus background in light-sheet fluorescence microscopy (LSFM) with scanned Bessel beams by subtraction imaging. Overlaying ${\pi }$π-phase retardation between the two equal parts of the Bessel beam across the entrance pupil of the objective lens, a hollow Bessel beam with zero intensity at the focal plane can be achieved. By optimizing the numerical aperture of the annular mask applied in the hollow Bessel beam, matched distributions of the ring system between the hollow Bessel beam and the conventional Bessel beam are achieved. By subtraction between the two LSFM images, the out-of-focus blur caused by the ring system of the Bessel beam can be significantly reduced. Comparison with conventional Bessel LSFM images exhibits a better sectioning capability and higher contrast.

Pharmacokinetic comparative study of tetramethylpyrazine and ferulic acid and their compatibility with different concentration of gastrodin and gastrodigenin on blood-stasis migraine model by blood-brain microdialysis method.

Tianma pills, a traditional formula made from Ligusticum chuanxiong and Gastrodia elata, are efficacious for the treatment of primary headache. Tetramethylpyrazine (TMP) and Ferulic acid (FA) are the bioactive ingredients of Ligusticum chuanxiong, while Gastrodin and Gastrodigenin are the bioactive ingredients of Gastrodia elata. Pharmacokinetic assessment of TMP, FA, gastrodin or gastrodigenin in blood or brain interstitial fluid (BIF) has been reported in healthy animals. However, the pharmacokinetic properties of TMP and FA have not been studied when they are co-administered in a blood-stasis migraine model. The present research investigated the pharmacokinetic behavior of TMP and FA after oral administration in the presence of different concentrations of gastrodin and gastrodigenin in a blood-stasis migraine model. Pharmacokinetic parameters were determined using blood-brain microdialysis in combination with the UHPLC-MS method. Compared to the control group, in which TMP and FA were administrated without gastrodin or gastrodigenin, the T1/2, MRT, Cmax and AUC0-∞ of TMP and FA were increased. These results indicate that varying concentrations of gastrodin and gastrodigenin play an important role in affecting the pharmacokinetics of TMP and FA. Low concentrations of gastrodin and gastrodigenin (similar to those found in Tianma pills) were more efficacious, validating the utility of the ancient formulation.

Studies of blood-brain barrier permeability of gastrodigenin in vitro and in vivo.

According to the basic theories of traditional Chinese medicine, Gastrodia elata (GE) is clinically utilized for the treatment of cephalalgia and migraine. The gastrodigenin (p-hydroxybenzyl alcohol, HBA), one of the effective components of GE, may pass through the blood-brain barrier (BBB) to exert its pharmacological effects. This study aimed to investigate BBB permeability of HBA via in vitro hCMEC/D3 BBB model and in vivo microdialysis in rats. For the establishment of in vitro BBB model, hCMEC/D3 cells were used to construct the monolayer. The integrity of the monolayer was evaluated by TEER measurements, expression analysis of tight junction proteins (claudin-5, zo-1 and occludin) and apparent permeability coefficients (Papp) of fluorescein disodium. During the 6-day incubation of hCMEC/D3 cells, the values of TEER gradually increased and maintained above 100 Ω·cm2. Besides, the expression levels of claudin-5 and zo-1 in hCMEC/D3 cells increased over time, and tended to be stable, suggesting that integrity of the monolayer has been completely established. Moreover, the Papp of fluorescein disodium was 3.94 × 10-7 cm·s-1 after administration for 180 min, indicating that the monolayer retains the characteristics of BBB and can restrict the diffusion of hydrophilic small-molecule compounds. A sensitive HPLC method was established for HBA detection, and the transport rate of HBA was assessed by a transwell system. HBA crossed the hCMEC/D3 BBB model rapidly, but a plateau was observed when HBA concentrations were relatively similar between the two sides of transwell. Permeability assay revealed that 32.91% of HBA could penetrate the in vitro BBB model after 240 min of administration. In vivo BBB permeability was evaluated by determining the concentrations of HBA in blood and brain simultaneously. Following HBA administration, the samples of microdialysis were collected at 20, 40 and 60 min, and then every 30 min until the procedure ended. Pharmacokinetic parameters of HBA showed that HBA could pass through BBB and reach its maximum concentration at 40 min in blood and brain tissue. Furthermore, AUC0-t and AUC0-inf for the brain-to-blood distribution ratio of HBA were 0.1925 and 0.2083, respectively, indicating that approximately 20% of HBA in blood could pass through the BBB and subsequently transported into the brain. Both in vitro and in vivo experiments confirmed that HBA could penetrate the BBB. In summary, the findings of this study highlight that a promising amount of HBA in blood can pass through the BBB and exerts its pharmacological effects on central nervous system (CNS) diseases.

Mechanism of traditional Chinese medicine in the treatment of allergic rhinitis.

OBJECTIVE: To review the major progress in mechanism of traditional Chinese medicine (TCM) in the treatment of allergic rhinitis (AR). METHODS: Contents about the treatment mechanism of TCM in the therapy of AR in this article were obtained from 22 original articles and reviews published in Chinese- and English-language journals. All of the references were searched by use of Pubmed (1997 - 2012). RESULTS: AR is one of the most common and most serious public health problems in children and young people. Many AR patients were worried about the possible adverse effects of synthetic drugs they were taking. Thus, they seek complementary and alternative therapy, such as TCM. TCM emphasized on the importance of holistic convalescence, not just the disease itself. The favorable safety profile of TCM makes well-acceptance by the general population. In the recent decade, more and more studies of TCM for AR are developed. These studies indicated that the treatment of allergic disorders with TCM therapy including herbal medicines and acupuncture are of safety and efficacy. The mechanism of TCM in the treatment of AR has been discussed. It has been reported that a number of the herbs in the Chinese herbal formulae used in the treatment possess anti-allergic, anti-inflammatory or immune modulation activity. Such function include the inhibition of the release or the activity of mast cell mediators (such as histamine), inhibition the induction of inflammation reaction by chemical agents, and down regulation of serum (immunoglobulin E) IgE levels or the activity of lymphocyte and/or macrophage. CONCLUSIONS: TCM are frequently used concurrently to improve the clinical efficacy. This review is focuses on the description of the actions mechanism of Chinese medicine's approach relevant to the treatment of AR.

Protective effects of polydatin against CCl(4)-induced injury to primarily cultured rat hepatocytes.

AIM:To investigate the protective effects of polydatin (PD) against injury to primarily cultured rat hepatocytes induced by CCl(4).METHODS:Rat hepatocytes were separated by methods of liver infusion in vivo and cultured medium (7.5X10(5) cells/mL). Two mL or 0.2mL was added into 24-well or 96-well plates respectively. Twenty-four hours after cell preculture, PD at concentrations of 10(-7) mol/L-10(-4)mol/L was added into each plate. At the same time injury to hepatocytes was induced by adding 10mmol/L CCl(4).Then, 0.1mL or 1mL culture solution was removed from the 96-well or 24-well plates at 6h, 12h, 24h and 48h after CCl14 intoxication respectively for the determination of GPT, GSH and MDA. At 48h, the survivability of rat hepatocytes was assayed by the MTT colormetric method.RESULTS:After CCl(4) challenge, the release of GPT and the formation of MDA in rat hepatocytes markedly increased and maintained at a high level in 48h, whereas PD with different concentrations could markedly inhibit this elevation with 10(-5)mol/L PD having the strongest effects and inhibiting rate was over 50%. PD could also improve the decreased content of GSH caused by CCl(4) in accordance with the doses used. CCl(4) evidently decreased the hepatocyte survivability from 91.0% ± 7.9% to 35.4% ± 3.8%. On the other hand, PD at 10(-7)mol/L-10(-4)mol/L could reverse this change and improve the cell survival rates to 56.1% ± 5.2%, 65.8% ± 5.0%, 88.7% ± 6.8% and 75.2% ± 7.3%, respectively.CONCLUSION: PD at 10(-7)mol/L-10(-4)mol/L could protect primarily cultured rat hepatocytes against CCl(4) induced injury.