Autism: The role of cholesterol in treatment

Cholesterol is essential for neuroactive steroid production, growth of myelin membranes, and normal embryonic and fetal development. It also modulates the oxytocin receptor, ligand activity and G-protein coupling of the serotonin-1A receptor. A deficit of cholesterol may perturb these biological mechanisms and thereby contribute to autism spectrum disorders (ASDs), as observed in Smith-Lemli-Opitz syndrome (SLOS) and some subjects with ASDs in the Autism Genetic Resource Exchange (AGRE). A clinical diagnosis of SLOS can be confirmed by laboratory testing with an elevated plasma 7DHC level relative to the cholesterol level and is treatable by dietary cholesterol supplementation. Individuals with SLOS who have such cholesterol treatment display fewer autistic behaviours, infections, and symptoms of irritability and hyperactivity, with improvements in physical growth, sleep and social interactions. Other behaviours shown to improve with cholesterol supplementation include aggressive behaviours, self-injury, temper outbursts and trichotillomania. Cholesterol ought to be considered as a helpful treatment approach while awaiting an improved understanding of cholesterol metabolism and ASD. There is an increasing recognition that this single-gene disorder of abnormal cholesterol synthesis may be a model for understanding genetic causes of autism and the role of cholesterol in ASD.     

巨大垂体腺瘤二次经蝶手术30例分析

目的探讨巨大垂体腺瘤二次经蝶手术策略、技巧及术后并发症处理方法。方法回顾性分析30例巨大垂体腺瘤二次经蝶手术病人的临床资料,对手术切除程度、术后症状、激素水平变化及并发症处理等进行总结和分析。结果术后病理结果显示：无功能性腺瘤22例,其中无功能性促肾上腺皮质激素腺瘤1例;生长激素腺瘤8例。功能性垂体腺瘤病人术后激素水平均不同程度下降。术后并发一过性尿崩症9例,脑脊液鼻漏4例,无死亡或严重并发症病例。术后3个月行MRI复查17例,肿瘤全切除4例,次全切除7例。部分切除6例。结论对单纯经蝶或经颅入路均无法一期全切除或术后随访肿瘤复发的巨大垂体腺瘤病例．二次经蝶手术应作为首选治疗方法。     

Doxycycline restrains glia and confers neuroprotection in a 6‐OHDA Parkinson model

Neuron–glia interactions play a key role in maintaining and regulating the central nervous system. Glial cells are implicated in the function of dopamine neurons and regulate their survival and resistance to injury. Parkinson's disease is characterized by the loss of dopamine neurons in the substantia nigra pars compacta, decreased striatal dopamine levels and consequent onset of extrapyramidal motor dysfunction. Parkinson's disease is a common chronic, neurodegenerative disorder with no effective protective treatment. In the 6‐OHDA mouse model of Parkinson's disease, doxycycline administered at a dose that both induces/represses conditional transgene expression in the tetracycline system, mitigates the loss of dopaminergic neurons in the substantia nigra compacta and nerve terminals in the striatum. This protective effect was associated with: (1) a reduction of microglia in normal mice as a result of doxycycline administration per se; (2) a decrease in the astrocyte and microglia response to the neurotoxin 6‐OHDA in the globus pallidus and substantia nigra compacta, and (3) the astrocyte reaction in the striatum. Our results suggest that doxycycline blocks 6‐OHDA neurotoxicity in vivo by inhibiting microglial and astrocyte expression. This action of doxycycline in nigrostriatal dopaminergic neuron protection is consistent with a role of glial cells in Parkinson's disease neurodegeneration. The neuroprotective effect of doxycycline may be useful in preventing or slowing the progression of Parkinson's disease and other neurodegenerative diseases linked to glia function.     

Local anesthetics inhibit glutamate release from rat cerebral cortex synaptosomes

Local anesthetics have been widely used for regional anesthesia and the treatment of cardiac arrhythmias. Recent studies have also demonstrated that low‐dose systemic local anesthetic infusion has neuroprotective properties. Considering the fact that excessive glutamate release can cause neuronal excitotoxicity, we investigated whether local anesthetics might influence glutamate release from rat cerebral cortex nerve terminals (synaptosomes). Results showed that two commonly used local anesthetics, lidocaine and bupivacaine, exhibited a dose‐dependent inhibition of 4‐AP‐evoked release of glutamate. The effects of lidocaine or bupivacaine on the evoked glutamate release were prevented by the chelation of extracellular Ca²⁺ ions and the vesicular transporter inhibitor bafilomycin A1. However, the glutamate transporter inhibitor dl ‐threo‐beta‐benzyl‐oxyaspartate did not have any effect on the action of lidocaine or bupivacaine. Both lidocaine and bupivacaine reduced the depolarization‐induced increase in [Ca²⁺]_C but did not alter 4‐AP‐mediated depolarization. Furthermore, the inhibitory effect of lidocaine or bupivacaine on evoked glutamate release was prevented by blocking the Ca_v2.2 (N‐type) and Ca_v2.1 (P/Q‐type) channels, but it was not affected by blocking of the ryanodine receptors or the mitochondrial Na⁺/Ca²⁺ exchange. Inhibition of protein kinase C (PKC) and protein kinase A (PKA) also prevented the action of lidocaine or bupivacaine. These results show that local anesthetics inhibit glutamate release from rat cortical nerve terminals. This effect is linked to a decrease in [Ca²⁺]_C caused by Ca²⁺ entry through presynaptic voltage‐dependent Ca²⁺ channels and the suppression of the PKA and PKC signaling cascades. Synapse 67:568–579, 2013 . © 2013 Wiley Periodicals, Inc.     

Synthesis of SrTiO3 submicron cubes with simultaneous and competitive photocatalytic activity for H2O splitting and CO2 reduction

Single crystalline strontium titanate (SrTiO₃) submicron cubes have been synthesized based on a molten salt method. The submicron cubes showed superior photocatalytic activity towards both water splitting and carbon dioxide reduction, in which methane (CH₄) and hydrogen (H₂) were simultaneously produced. The average production rate of methane up to 8 h is 4.39 μmol g⁻¹ h⁻¹ but drops to 0.46 μmol g⁻¹ h⁻¹. However, the average production rate of hydrogen is 14.52 before 8 h but then increases to 120.23 μmol g⁻¹ h⁻¹ after 8 h. The rate change of the two processes confirms the competition between the H₂O splitting and CO₂ reduction reactions. Band structure and surface characteristics of the SrTiO₃ submicron cubes were characterized by diffuse reflective UV-Vis spectroscopy, Mott–Schottky analysis, X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). The results reveal that the simultaneous and competitive production of methane and hydrogen is due to a thermodynamics factor, as well as the competition between the adsorption of carbon dioxide and water molecules on the surface of the faceted SrTiO₃. This work demonstrates that SrTiO₃ photocatalysts are efficient in producing sustainable fuels via water splitting and carbon dioxide reduction reactions.

There is a clear competitive relationship between water splitting and photocatalytic reduction of carbon dioxide in the whole process of photocatalytic reduction of carbon dioxide with the prepared cubic SrTiO₃ as a photocatalyst.     

MRI-based treatment planning for brain stereotactic radiosurgery: Dosimetric validation of a learning-based pseudo-CT generation method

Magnetic resonance imaging (MRI)-only radiotherapy treatment planning is attractive since MRI provides superior soft tissue contrast without ionizing radiation compared with computed tomography (CT). However, it requires the generation of pseudo CT from MRI images for patient setup and dose calculation. Our machine-learning-based method to generate pseudo CT images has been shown to provide pseudo CT images with excellent image quality, while its dose calculation accuracy remains an open question. In this study, we aim to investigate the accuracy of dose calculation in brain frameless stereotactic radiosurgery (SRS) using pseudo CT images which are generated from MRI images using the machine learning-based method developed by our group. We retrospectively investigated a total of 19 treatment plans from 14 patients, each of whom has CT simulation and MRI images acquired during pretreatment. The dose distributions of the same treatment plans were calculated on original CT simulation images as ground truth, as well as on pseudo CT images generated from MRI images. Clinically-relevant DVH metrics and gamma analysis were extracted from both ground truth and pseudo CT results for comparison and evaluation. The side-by-side comparisons on image quality and dose distributions demonstrated very good agreement of image contrast and calculated dose between pseudo CT and original CT. The average differences in Dose-volume histogram (DVH) metrics for Planning target volume (PTVs) were less than 0.6%, and no differences in those for organs at risk at a significance level of 0.05. The average pass rate of gamma analysis was 99%. These quantitative results strongly indicate that the pseudo CT images created from MRI images using our proposed machine learning method are accurate enough to replace current CT simulation images for dose calculation in brain SRS treatment. This study also demonstrates the great potential for MRI to completely replace CT scans in the process of simulation and treatment planning.     

MEBT/MEBO对慢性难愈合创面组织中CK10表达水平的影响

目的通过对比观察不同治疗方案对大鼠创面组织内CK10表达水平的影响,进一步揭示皮肤再生医疗技术(moist exposed burn therapy/moist exposed burn ointment, MEBT/MEBO)治疗慢性难愈合创面的部分作用机制。方法将90只SPF级Wistar大鼠随机分为空白组(18只)、急创组(18只)、慢创组(18只)、rb-bFGF组(18只)及MEBO组(18只),其中空白组大鼠仅做备皮处理,急创组大鼠建立急性创面模型,慢创组、 rb-bFGF组及MEBO组大鼠建立慢性难愈合创面模型,且空白组大鼠局部皮肤予以生理盐水纱布湿敷,急创组及慢创组大鼠创面予以生理盐水治疗, rb-bFGF组大鼠创面予以重组牛碱性成纤维细胞生长因子(recombinant bovine basic fibroblast growth factor, rb-bFGF)凝胶治疗, MEBO组大鼠创面予以湿润烧伤膏(moist exposed burn ointment, MEBO)治疗,分别于治疗第3、 7、 14天对比观察5组大鼠皮肤或创面组织的形态学变化及CK10的表达水平。结果 (1)治疗第3天,空白组大鼠皮肤组织形态与正常皮肤组织形态无明显差异,其他各组大鼠创面组织水肿明显,可见大量炎性细胞浸润及少量成纤维细胞与新生毛细血管分布;治疗第14天,空白组大鼠皮肤组织形态与正常皮肤组织形态无明显差异,慢创组大鼠创面组织内仍有少量炎性细胞浸润,且有大量排列不规则的成纤维细胞分布,而急创组、 rb-bFGF组及MEBO组大鼠创面组织内可见排列整齐的新生毛细血管及完整的毛囊和皮脂腺等皮肤附属器,组织结构接近于正常皮肤组织。(2)治疗第3、 7、 14天,空白组大鼠皮肤组织内CK10表达水平无明显变化,P 0.05,差异无统计学意义;而急创组、慢创组、 rb-bFGF组及MEBO组大鼠创面组织内CK10表达水平呈现逐渐升高的趋势,P均0.05,差异具有统计学意义。(3)治疗第7、 14天,急创组、rb-bFGF组和MEBO组大鼠创面组织内CK10表达水平均明显高于慢创组,P均0.05,差异具有统计学意义;治疗第3、 7、 14天, rb-bFGF组和MEBO组大鼠创面组织内CK10表达水平均无明显差异,P均 0.05,差异无统计学意义。结论 MEBT/MEBO治疗慢性难愈合创面的疗效不亚于rb-bFGF凝胶,且改变表皮干细胞的外界生存环境,促进表皮干细胞向正常表皮细胞增殖、分化,可能是其促进慢性难愈合创面修复的作用机制。     

Synthesis,cytotoxic activity,and 2D‐ and 3D‐QSAR studies of 19‐carboxyl‐modified novel isosteviol derivatives as potential anticancer agents

Two series of novel acylthiosemicarbazide and oxadiazole fused‐isosteviol derivatives were synthesized based on the 19‐carboxyl modification. The target compounds were evaluated for their cytotoxicities against three cancer cell lines (HCT‐116, HGC‐27, and JEKO‐1) using an MTT assay. Lead compounds from the acylthiosemicarbazides ( 4 ) showed IC₅₀ values in the lower micromolar range. For example, compounds ( 4i , 4l , 4m , 4r, and 4s ) exhibited significant inhibitory activities against the three cell lines with IC₅₀ values of 0.95–3.36 μm . Furthermore, 2D‐HQSAR and 3D‐topomer CoMFA analyses were established, which could be used to develop second generation of isosteviol derivatives as anticancer agents.