Permeability determination and pharmacokinetic study of nobiletin in rat plasma and brain by validated high-performance liquid chromatography method

In the present study, we are reporting permeability and pharmacokinetics of nobiletin in rat plasma and brain, using a validated reverse phase high performance liquid chromatographic method. Protein precipitation method was used for the extraction of nobiletin and coumarin (IS) from rat plasma and brain tissue. The system was run in isocratic mode with mobile phase consisting of potassium dihydrogen ortho-phosphate (pH 4.5; 0.04 mM) and acetonitrile in ratio of 50:50, v/v. The total chromatographic run time was 9.0 min. The method was proved to be accurate and precise at linearity range of 0.05–10 μg/mL with a correlation coefficient (r) of ≥ 0.994 in rat plasma and ≥ 0.995 in rat brain. The intra- and inter-day precision and accuracy values are found to be within the assay variability limits as per the FDA guidelines. Nobiletin was found stable in the battery of stability studies viz., bench-top, auto-sampler, freeze/thaw cycles and long term storage in a freezer at − 70 ± 10 °C. Maximum concentrations of nobiletin in both plasma and brain were observed at 1 h after single oral dosing (50 mg/kg). The maximum concentration in plasma and brain were 1.78 and 4.20 μg/mL, respectively. The AUC_0–t in plasma and brain were 7.49 and 20.66 μg·h/mL, respectively. The mean elimination half life (t_1/2) in plasma and brain were 1.80 and 11.42 h, respectively. The Parallel Artificial Membrane Permeability Assay (PAMPA) permeability of nobiletin was found to be high at both pH 4.0 and 7.0.     

酸枣仁散对运输应激大鼠脑内5-HT表达的影响

为研究运输应激对脑内五羟色胺(5-hydroxytryptamine,5-HT)表达的影响及酸枣仁散对运输应激的调控作用,试验采用摇床模拟公路运输途中的摇晃、高温和拥挤等因素,建立大鼠运输应激模型(35℃,60r/min,每天应激2h,连续7d)。将40只大鼠随机分为对照组、酸枣仁组、应激组和应激+酸枣仁组,分别处理7d后,断头取脑,利用酶联免疫吸附法(ELISA)和免疫组化法检测各组大鼠脑区5-HT含量变化及分布。酶联免疫吸附法检测结果显示,与对照组相比,应激组大鼠中缝核、海马和纹状体等脑区5-HT表达量均明显减少(P0.05),应激+酸枣仁组较应激组5-HT表达量显著增加(P0.05)。免疫组化结果显示,在中缝背核及其亚核DRDsh、DRv和DRc亚核,应激组大鼠5-HT灰度值与对照组相比显著下降(P0.05),应激+酸枣仁组与应激组相比显著上升(P0.05)。以上结果表明,运输应激可以导致中枢神经系统部分脑区5-HT含量下降,而酸枣仁散可能通过上调脑内5-HT的含量来调控运输应激。     

保留畜禽脑脊髓附韧带骨架标本制作技术

用“保留畜禽脑脊髓附韧带”技术制作的整体骨架标本保留脑脊髓和关节韧带，不需脱脂、漂白，不必用铁丝穿制，较传统的沤制，煮制方法省时省力，节省资金，即能显著畜禽生态姿势，又能体现骨，关节，韧带标本的完整性。用该技术制作的畜禽整体骨架标本１５ａ未见虫蛀，霉变，散架，变形，无损无缺，色泽逼真，是解剖学骨骼标本制作的１种新方法。     

A slowly progressive retinopathy in the Shetland Sheepdog

Objective To describe a slowly progressive retinopathy (SPR) in Shetland Sheepdogs. Animals Forty adult Shetlands Sheepdogs with ophthalmoscopic signs of SPR and six normal Shetland Sheepdogs were included in the study. Procedure Ophthalmic examination including slit‐lamp biomicroscopy and ophthalmoscopy was performed in all dogs. Electroretinograms and obstacle course‐test were performed in 13 affected and 6 normal dogs. The SPR dogs were subdivided into two groups according to their dark‐adapted b‐wave amplitudes. SPR1‐dogs had ophthalmoscopic signs of SPR, but normal dark‐adapted b‐wave amplitudes. Dogs with both ophthalmoscopic signs and subnormal, dark‐adapted b‐wave amplitudes were assigned to group SPR2. Eyes from two SPR2 dogs were obtained for microscopic examination. Results The ophthalmoscopic changes included bilateral, symmetrical, greyish discoloration in the peripheral tapetal fundus with normal or marginally attenuated vessels. Repeated examination showed that the ophthalmoscopic changes slowly spread across the central parts of the tapetal fundus, but did not progress to obvious neuroretinal thinning presenting as tapetal hyper‐reflectivity. The dogs did not appear seriously visually impaired. SPR2 showed significantly reduced b‐wave amplitudes throughout dark‐adaptation. Microscopy showed thinning of the outer nuclear layer and abnormal appearance of rod and cone outer segments. Testing for the progressive rod–cone degeneration ( prcd )‐mutation in three dogs with SPR was negative. Conclusion Slowly progressive retinopathy is a generalized rod–cone degeneration that on ophthalmoscopy looks similar to early stages of progressive retinal atrophy. The ophthalmoscopic findings are slowly progressive without tapetal hyper‐reflectivity. Visual impairment is not obvious and the electroretinogram is more subtly altered than in progressive retinal atrophy. The etiology remains unclear. SPR is not caused by the prcd‐mutation.     

三种有机磷农药胚胎期暴露对新生鼠脑组织结构的影响

探讨了3种常用的有机磷农药胚胎期暴露对新生鼠脑组织结构的影响。在母鼠妊娠期7.5～11.5 d时,连续5 d每天分别经皮下注射2 mg/kg bw的二嗪磷(diazinon)、2 mg/kg bw的毒死蜱(chlorpyrifos)及50 mg/kg bw乙酰甲胺磷(acephate),显微镜下观察并计数大脑皮层S1区胶质细胞和神经元数量及比率,以及海马CA1、CA3区锥体细胞的数量及体积密度。结果表明,二嗪磷与毒死蜱处理分别使得大脑皮层S1区胶质细胞数减少了14.29%和21.43%;毒死蜱处理导致胶质细胞与神经元比率下降了24.19%;二嗪磷与毒死蜱处理后海马CA1区锥体细胞数量分别下降了9.30％与20.93％,毒死蜱处理后锥体细胞体积密度下降了27.05％;二嗪磷与毒死蜱处理后海马CA3区锥体细胞数量分别下降了22.22％和19.44％,锥体细胞体积密度分别下降了23.54％和18.98％;而乙酰甲胺磷对新生鼠大脑皮层与海马细胞均无明显影响。     

REGIONAL BINDING INDEX OF THE RADIOLABELED SELECTIVE 5-HT2A ANTAGONIST 123I-5-I-R91150 IN THE NORMAL CANINE BRAIN IMAGED WITH SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY

The pattern of the specific 5-HT2A (5-hydroxytryptamine 2A receptor) antagonist 123I-5-I-R91150 was measured in 10 healthy dogs without neurologic and behavior abnormalities. Eight cortical regions (left and right fronto-, temporo-, parieto-, and occipitocortical area), one global subcortical region (including the thalamic system) were compared with a reference region lacking receptors; that is, the cerebellum. The 123I labeled radioligand was injected intravenously 100-200 minutes before acquisition. Both transmission and emission data were obtained with a triple head gamma camera equipped with high-resolution fanbeam collimators. The emission data were corrected for scatter and attenuation. To delineate different cerebral regions more accurately, the regions of interest (ROI) defined in a former study on brain perfusion measured with 99mTc-ethyl cysteinate dimer (ECD) in the same dogs were used. The co-registration of the 99mTc-ECD and the 123I-5-I-R91150, obtained from each dog, was realized with the help of corresponding transmission maps. By normalizing each regional cerebral activity to the activity observed in the cerebellum, the regional radioactivity (binding index) could be relatively quantified. Highest brain uptake was noted in the frontocortical brain areas (right: 1.85, left: 1.89), followed by the temporocortical region (right: 1.58, left: 1.56). Least uptake was noted in the more caudal and middle brain regions [occipito- (right: 1.46, left: 1.41), parietocortical (right: 1.30, left: 1.26), and striatal region (1.19)]. No gender nor age influence was noted in this series. The 123I labeled serotonin-2A receptor ligand seems to have similar cortical binding in the normal canine brain, as shown in humans and other animal species. A frontocortical to occipitocortical (rostrocaudal) binding index gradient was identified within the dog, which has not been seen in imaging studies from humans and other animal species. The significance of these results will need further investigation. This normative data can be used to compare regional brain uptake of the 123I-radioligand to dogs with behavioral disorders related to the serotonergic system, in future studies.     

MAGNETIC RESONANCE IMAGING OF THE BRAIN OF NORMAL NEONATAL FOALS

Magnetic resonance imaging (MRI) was performed on gthe brain of 5 normal, anesthetized, neonatal (age 3-to-6 days) Quarter Horse foals. The objectives of the study were to develop a technique for imaging the brain of neonatal foals, and to ascertain their normal brain anatomy. Interavenous propofol was administered for induction and maintenance of general anesthesia. Using spin echo MR techniques, T1 weighted sagittal and transverse views, and spin density and T2 weighted transverse views were successfully made of each foal. MR images provided excellent visualization of many anatomic struictures of the brain and head. MRI of the bgrain is feasible for selected neonantal equine patients.     

CANINE BRAIN ANATOMY ON MAGNETIC RESONANCE IMAGES

Magnetic resonance (MR) images of the canine brain were acquired during investigation of dogs with neurologic disease. A paramagnetic contrast medium was used for enhancement. MR provided images with excellent contrast between grey and white matter, as well as brain tissue and cerebrospinal fluid. Good resolution and anatomic detail of the canine brain were obtained. A series of images was compiled and labelled as a reference for MR anatomy of the canine brain.     

G-CSF对脑挫伤大鼠血清及脑组织中NO、MDA和SOD含量的影响

目的观察粒细胞集落刺激因子（G-CSF）对脑挫伤大鼠血清及脑组织中一氧化氮（NO）、丙二醛（MDA）和超氧化物歧化酶（SOD）含量的影响,探讨G-CSF在治疗脑挫伤中的作用.方法将大鼠随机分为治疗组、对照组和正常组,采用自由落体法致SD大鼠脑挫伤动物模型,正常组不致伤.治疗组脑挫伤2h后开始应用G-CSF（浓度为2mg/L）一次性皮下注射50μg/kg治疗.对照组和正常组皮下注射等量生理盐水.给药结束后24h检测治疗组、对照组及正常组大鼠血清及脑组织中NO、MDA和SOD的含量.结果脑挫伤后,对照组大鼠血清及脑组织中NO和MDA含量明显高于正常组,SOD的活性明显低于正常组.治疗组大鼠血清及脑组织中NO和MDA含量明显低于对照组,SOD的活性明显高于对照组.结论G-CSF能有效地提高脑挫伤大鼠血清及脑组织中SOD的活性,降低NO和MDA含量,保护脑组织,改善脑水肿,从而起到了一定的治疗作用.