Depolarization and Activation of Dihydropyridine-Sensitive Ca2+ Channels Stimulate Inositol Phosphate Accumulation in Photoreceptor-Enriched Chick Retinal Cell Cultures

Abstract: Elevated concentrations of extracellular K⁺ increased inositol phosphate accumulation in primary cultures of chick retinal photoreceptors and multipolar neurons. K⁺-evoked stimulation of inositol phosphate accumulation was greater in photoreceptor-enriched cell cultures than in cultures where multipolar neurons were the predominant cell type. Destroying multipolar neurons, but not photoreceptors, with kainic acid and N -methyl- d -aspartate did not reduce the K⁺-evoked stimulation of inositol phosphate accumulation. Both of these observations indicate that the observed effects occur in photoreceptor cells. The K⁺-evoked stimulation of inositol phosphate accumulation was blocked by omitting Ca²⁺ from the incubation medium or by adding the dihydropyridine-sensitive Ca²⁺-channel antagonists, nitrendipine and nifedipine. Bay K 8644, a dihydropyridine agonist, stimulated inositol phosphate accumulation and enhanced the effect of K⁺. ω-Conotoxin GVIA, an inhibitor of N-type Ca²⁺ channels, had no significant effect on K⁺-stimulated inositol phosphate accumulation. Pretreatment with pertussis toxin neither blocked K⁺-evoked inositol phosphate accumulation nor altered the inhibitory effect of nifedipine. K⁺-evoked inositol phosphate accumulation appears to reflect activation of phosphatidylinositol-specific phospholipase C, as it is inhibited by U-73122. These results indicate that Ca²⁺ influx through voltage-gated, dihydropyridine-sensitive channels activates phospholipase C in photoreceptor inner segments and/or synaptic terminals.     

Photobiomodulation by diffusing optical fiber on spinal cord: A feasibility study in piglet model

Previous studies on spinal cord injury (SCI) have confirmed that percutaneous photobiomodulation (PBM) therapy can ameliorate immunoinflammatory responses at sites of injury, accelerate nerve regeneration, suppress glial scar formation and promote the subsequent recovery of locomotor function. The current study was performed to evaluate a large‐animal model employing implanted optical fibers to accurately irradiate targeted spinal segments. The method's feasibility and irradiation parameters that do not cause phototoxic reaction were determined, and the methodology of irradiating the spinal cord with near‐infrared light was investigated in detail. A diffusing optical fiber was implanted above the T9 spinal cord of Bama miniature pigs and used to transfer near‐infrared light (810 nm) onto the spinal cord surface. After daily irradiation with 200, 300, 500 or 1000 mW for 14 days, both sides of the irradiated area of the spinal cord were assessed for temperature changes. The condition of the spinal cord and the position of optical fiber were investigated by magnetic resonance imaging (MRI), and different parameters indicating temperature increases or phototoxicity were measured on the normal spinal cord surface due to light irradiation (ie, heat shock responses, inflammatory reactions and neuronal apoptosis), and the animals' lower‐limb neurological function and gait were assessed during the irradiation process. The implanted device was stable inside the freely moving animals, and light energy could be directly projected onto the spinal cord surface. The screening of different irradiation parameters preliminary showed that direct irradiation onto the spinal cord surface at 200 and 300 mW did not significantly increase the temperature, stress responses, inflammatory reactions and neural apoptosis, whereas irradiation at 500 mW slightly increased these parameters, and irradiation at 1000 mW induced a significant temperature increase, heat shock, inflammation and apoptosis responses. HE staining of spinal cord tissue sections did not reveal any significant structural changes of the tissues compared to the control group, and the neurological function and gait of all irradiated animals were normal. In this study, we established an in‐vivo optical fiber implantation method, which might be safe and stable and could be used to directly project light energy onto the spinal cord surface. This study might provide a new perspective for clinical applications of PBM in acute SCI.     

Neuroprotective effect of ketamine against TNF-α-induced necroptosis in hippocampal neurons

Tumour necrosis factor-α (TNF-α), a crucial cytokine, has various homeostatic and pathogenic bioactivities. The aim of this study was to assess the neuroprotective effect of ketamine against TNF-α-induced motor dysfunction and neuronal necroptosis in male C57BL/6J mice in vivo and HT-22 cell lines in vitro. The behavioural testing results of the present study indicate that ketamine ameliorated TNF-α-induced neurological dysfunction. Moreover, immunohistochemical staining results showed that TNF-α-induced brain dysfunction was caused by necroptosis and microglial activation, which could be attenuated by ketamine pre-treatment inhibiting reactive oxygen species production and mixed lineage kinase domain-like phosphorylation in hippocampal neurons. Therefore, we concluded that ketamine may have neuroprotective effects as a potent inhibitor of necroptosis, which provides a new theoretical and experimental basis for the application of ketamine in TNF-α-induced necroptosis-associated diseases.     

Efficacy and Safety of Parecoxib/Phloroglucinol Combination Therapy Versus Parecoxib Monotherapy for Acute Renal Colic: A Randomized,Double-Blind Clinical Trial

To investigate whether the addition of phloroglucinol to parecoxib could improve the efficacy in patients with acute renal colic. Patients of acute renal colic were randomly allocated to receive intravenous Parecoxib 40 mg plus placebo or Parecoxib 40 mg plus phloroglucinol 80 mg, respectively. Pain intensity was recorded using a visual analog scale (VAS) before drug administration and 5, 15, 30, 60, and 120 min after treatment start. The primary outcome was the mean pain intensity difference (PID) at each checkpoint and the effectiveness of drugs (≥50 % decrease in VAS score at the end checkpoint). The need for rescue analgesics and the incidence of adverse effects were considered as secondary outcome of the study. Among 236 patients enrolled in the study, 119 patients received intravenous parecoxib plus placebo and 114 patients received intravenous parecoxib plus phloroglucinol, the remaining 3 patients given up treatment. Baseline demographics were similar between two groups. There are significant differences in the PID at 15 and 30 min between two groups (P _15 min = 0.011, P _30 min = 0.013). Rescue analgesics were required by 17 patients (14.3 %) receiving parecoxib, 7 patients (6.1 %) receiving parecoxib plus phloroglucinol (P = 0.041). There were no differences in PID at other checkpoints between two groups, as well as in the incidence of adverse events and the drug effectiveness. Parecoxib in combination with phloroglucinol for acute renal colic has a faster action, also reduces the demand of rescue analgesics.     

Theoretical insight into the structural mechanism for the binding of vinblastine with tubulin

Vinblastine (VLB) is one of vinca alkaloids with high cytotoxicity toward cancer cells approved for clinical use. However, because of drug resistance, toxicity, and other side effects caused from the use of VLB, new vinca alkaloids with higher cytotoxicity toward cancer cells and other good qualities need to develop. One strategy is to further study and better understand the essence why VLB possesses the high cytotoxicity toward cancer cells. In present work, by using molecular simulation, molecular docking, density functional calculation, and the crystal structure of α,β-tubulin complex, we find two modes labeled in catharanthine moiety (CM) and vindoline moiety (VM) modes of VLB bound with the interface of α,β-tubulin to probe the essence why VLB has the high cytotoxicity toward cancer cells. In the CM mode, nine key residues B-Ser178, B-Asp179, B-Glu183, B-Tyr210, B-Asp226, C-Lys326, C-Asp327, C-Lys336, and C-Lys352 from the α,β-tubulin complex are determined as the active sites for the interaction of VLB with α,β-tubulin. Some of them such as B-Ser178, B-Glu183, B-Tyr210, B-Asp226, C-Lys326, C-Asp327, and C-Lys336 are newly identified as the active sites in present work. The affinity between VLB and the active pocket within the interface of α,β-tubulin is ?60.8 kJ mol^?1 in the CM mode. In the VM mode, that is a new mode established in present paper, nine similar key residues B-Lys176, B-Ser178, B-Asp179, B-Glu183, B-Tyr210, B-Asp226, C-Lys326, C-Asp327, and C-Lys336 from the α,β-tubulin complex are found as the active sites for the interaction with VLB. The difference is from one key residue C-Lys352 in the CM mode changed to the key residue B-Lys176 in the VM mode. The affinity between VLB and the active pocket within the interface of α,β-tubulin is ?96.3 kJ mol^?1 in the VM mode. Based on the results obtained in present work, and because VLB looks like two faces, composed of CM and VM both to have similar polar active groups, to interact with the active sites, we suggest double-faces sticking mechanism for the binding of VLB to the interface of α,β-tubulin. The double-faces sticking mechanism can be used to qualitatively explain high cytotoxicity toward cancer cells of vinca alkaloids including vinblastine, vincristine, vindestine, and vinorelbine approved for clinical use and vinflunine still in a phase III clinical trial. Furthermore, this mechanism will be applied to develop novel vinca alkaloids with much higher cytotoxicity toward cancer cells.     

Enhanced phenol bioavailability by means of photocatalysis

Phenol was investigated for the ability of TiO₂ photocatalysis to increase its bioavailability as an electron donor for denitrification. The rate of nitrate removal by denitrification was increased by up to 2.6-fold by exposing phenol to photocatalysis for 30 min, although the rate decreased with increasing photocatalysis. The increased denitrification rate appeared to be associated with the photocatalytic production of carboxylic acids, but the slow down correlated to the production of catechol and hydroquinone.     

Transarterial Chemoembolization in Combination with Local Therapies for Hepatocellular Carcinoma: A Meta-Analysis

Background

In previous randomized trials, transarterial chemoembolization (TACE) has shown an improvement of survival rate in hepatocellular carcinoma (HCC) when combined with radiofrequency ablation (RFA), percutaneous ethanol injection (PEI) or other therapies. The aim of this meta-analysis was to evaluate the effectiveness of combination therapy of TACE with RFA, PEI, radiotherapy (RT), three-dimensional conformal radiation therapy (3D-CRT) or High-Intensity Focused Ultrasound (HIFU).

Methods

Randomized or nonrandomized studies comparing TACE combined with RFA, PEI, RT, 3D-CRT or HIFU with TACE alone for HCC were included. Meta-analysis was performed using a fix-effects model in RCTs and a random-effects model among the observational studies.

Results

10 randomized trials and 18 observational studies matched the selection criteria, including 2497 patients (682 in RCTs, 1815 in non-RCTs). Meta-analysis of RCTs showed that the combination of TACE and PEI ((RR)_{1 -}year=1.10, 95%CI=0.99-1.22, p=0.073; (RR)_{3 -}year=2.32, 95%CI=1.52-3.53, p<0.001), TACE+RT ((RR)_{1 -}year=1.37, 95%CI=1.11-1.70, p=0.004; (RR)_{3 -}year=2.32, 95%CI=1.44-3.75, p=0.001) were associated with higher survival rates. The results of observational studies were in good consistency with that of RCTs. Furthermore, TACE plus 3D-CRT ((RR)_{1 -}year=1.22, 95%CI=1.06-1.41, p=0.005; (RR)_{3 -}year=2.05, 95%CI=1.48-2.84, p<0.001) and TACE plus HIFU ((RR)_{1 -}year=1.16, 95%CI=1.01-1.33, p=0.033; (RR)_{3 -}year=1.66, 95%CI=1.12-2.45, p=0.011) have introduced marked survival benefit when pooling results from observational studies.

Conclusions

This meta-analysis demonstrated that TACE combined with local treatments, especially PEI, HIFU or 3D-CRT could improve the overall survival status than performing TACE alone. Importantly, these results need to be validated in further high-quality clinical trials.     

CD138免疫磁珠细胞分选的FISH技术在多发性骨髓瘤诊断中的应用

为了分析CD138免疫磁珠细胞分选的染色体荧光原位杂交(FISH)技术在提高多发性骨髓瘤(MM)细胞遗传学异常检测敏感性的作用。本研究选取我院收治的30例确诊MM的患者为研究对象,分离骨髓单个核细胞,应用探针组合,同时采用2种方法进行细胞遗传学检测:实验组采用CD138免疫磁珠分选浆细胞后行荧光原位杂交技术(MACS-FISH)检测;对照组直接荧光原位杂交技术(D-FISH)检测。结果:30例MM患者,实验组采用CD138 MACS-FISH检出率为83.3%,对照组D-FISH法细胞遗传异常检出率为46.7%,两组差异具有统计学意义(p<0.05)。研究结果表明:分析不同类型的细胞遗传异常,MACS-FISH法1q21检出率为46.7%,RB1检出率为50.0%,Ig H检出率为70.0%,P53检出率为20.0%;D-FISH法检出率分别为23.3%,30.0%、36.7%、10.0%。通过细胞核型分析,30例MM患者中,发现5例患者为异常核型,仅为16.7%,其中1例患者为单一结构异常,复杂异常核型患者为4例。我们的研究结论表明:进行CD138免疫磁珠分选浆细胞的FISH技术在多发性骨髓瘤诊断应用中可显著提高细胞遗传学异常检测敏感性,具有临床推广应用的价值。     

Diversity of the Sediment Microbial Community in the Aha Watershed (Southwest China) in Response to Acid Mine Drainage Pollution Gradients

Located in southwest China, the Aha watershed is continually contaminated by acid mine drainage (AMD) produced from upstream abandoned coal mines. The watershed is fed by creeks with elevated concentrations of aqueous Fe (total Fe > 1 g/liter) and SO₄²⁻ (>6 g/liter). AMD contamination gradually decreases throughout downstream rivers and reservoirs, creating an AMD pollution gradient which has led to a suite of biogeochemical processes along the watershed. In this study, sediment samples were collected along the AMD pollution sites for geochemical and microbial community analyses. High-throughput sequencing found various bacteria associated with microbial Fe and S cycling within the watershed and AMD-impacted creek. A large proportion of Fe- and S-metabolizing bacteria were detected in this watershed. The dominant Fe- and S-metabolizing bacteria were identified as microorganisms belonging to the genera Metallibacterium, Aciditerrimonas, Halomonas, Shewanella, Ferrovum, Alicyclobacillus, and Syntrophobacter. Among them, Halomonas, Aciditerrimonas, Metallibacterium, and Shewanella have previously only rarely been detected in AMD-contaminated environments. In addition, the microbial community structures changed along the watershed with different magnitudes of AMD pollution. Moreover, the canonical correspondence analysis suggested that temperature, pH, total Fe, sulfate, and redox potentials (E_h) were significant factors that structured the microbial community compositions along the Aha watershed.