酶法合成中丙氨酸的检测

本文建立了丙氨酸在醋酸缓冲液中形成丙氨酸-铜配离子及其十二烷基磺酸配离子对,使其紫外无吸收的丙氨酸在230nm处于有强紫外吸收,从而对酶法合成中的丙氨酸进行定量分析．该法在0～50mg／L范围内有良好的线性关系,直线方程为A(230)=0.01712·C（n=5）C：mg／L）。相关系数为0．9994,回收率为96．8％～104．0％,且该法不受酶反应液的影响,实验结果证明该检测体系简单、实用、测定结果可靠。     

Parapapillary Atrophy: Histological Gamma Zone and Delta Zone

Background

To examine histomorphometrically the parapapillary region in human eyes.

Methodology/Principal Findings

The histomorphometric study included 65 human globes (axial length:21–37 mm). On anterior-posterior histological sections, we measured the distance Bruch''s membrane end (BME)-optic nerve margin (“Gamma zone”), BME-retinal pigment epithelium (RPE) (“Beta zone”), BME-beginning of non-occluded choriocapillaris, and BME-beginning of photoreceptor layer. “Delta zone” was defined as part of gamma zone in which blood vessels of at least 50 µm diameter were not present over a length of >300 µm. Beta zone (mean length:0.35±0.52 mm) was significantly (P = 0.01) larger in the glaucoma group than in the non-glaucomatous group. It was not significantly (P = 0.28) associated with axial length. Beta zone was significantly (P = 0.004) larger than the region with occluded choriocapillaris. Gamma zone (mean length:0.63±1.25 mm) was associated with axial length (P<0.001;r² = 0.73) with an increase starting at an axial length of 26.5 mm. It was not significantly (P = 0.24) associated with glaucomatous optic neuropathy. Delta zone (present only in eyes with axial length of ≥27 mm) was associated with axial length (P = 0.001) and scleral flange length (P<0.001) but not with glaucoma (P = 0.73).

Conclusions/Significance

Parapapillary gamma zone (peripapillary sclera without overlying choroid, Bruch''s membrane and deep retinal layers) was related with axial globe elongation and was independent of glaucoma. Delta zone (no blood vessels >50 µm diameter within gamma zone) was present only in highly axially elongated globes and was not related with glaucoma. Beta zone (Bruch''s membrane without RPE) was correlated with glaucoma but not with globe elongation. Since the region with occluded choriocapillaris was smaller than beta zone, complete loss of RPE may have occurred before complete choriocapillaris closure.     

RNA interference as a gene silencing therapy for mutant MYOC protein in primary open angle glaucoma

Bronchoalveolar lavage (BAL) is a useful diagnostic tool in interstitial lunge diseases (ILD). However, differential cell counts are often non specific and immunocytochemistry is time consuming. Staining of glyoproteins by periodic acid Schiff (PAS) reaction may help in discriminating different forms of ILD. In addition, PAS staining is easy to perform. BAL cells from patients with idiopathic pulmonary fibrosis (IPF) (n = 8), sarcoidosis (n = 9), and extrinsic allergic alveolitis (EAA) (n = 2) were investigated. Cytospins from BAL cells were made and cells were stained using Hemacolor quick stain and PAS staining. Lymphocytic alveolitis was found in sarcoidosis and EAA whereas in IPF both lymphocytes and neutrophils were increased. PAS positive cells were significantly decreased in EAA compared to IPF and sarcoidosis (25.5% ± 0.7% vs 59.8% ± 25.1% and 64.0% ± 19.7%, respectively) (P < 0.05). No significant correlation between PAS positive cells and inflammatory cells was observed. These results suggest that PAS staining of BAL cells may provide additional information in the differential diagnosis of ILD. Further studies ware warranted to evaluate PAS staining in larger numbers of BAL from patients with ILD.     

Metabolic Changes in the Visual Cortex of Binocular Blindness Macaque Monkeys: A Proton Magnetic Resonance Spectroscopy Study

Purpose

To evaluate proton magnetic resonance spectroscopy (¹H-MRS) in a study of cross-modal plasticity in the visual cortex of binocular blindness macaque monkeys.

Materials and Methods

Four healthy neonatal macaque monkeys were randomly divided into 2 groups, with 2 in each group. Optic nerve transection was performed in both monkeys in the experimental group (group B) to obtain binocular blindness. Two healthy macaque monkeys served as a control group (group A). After sixteen months post-procedure, ¹H-MRS was performed in the visual cortex of all monkeys. We compared the peak areas of NAA, Cr, Cho, Glx and Ins and the ratios of NAA/Cr, Cho/Cr, Glx/Cr and Ins/Cr of each monkey in group B with group A.

Results

The peak area of NAA and the NAA/Cr ratio in the visual cortex of monkey 4 in group B were found to be dramatically decreased, the peak area of NAA slightly decreased and the NAA/Cr ratio clearly decreased in visual cortex of monkey 3 in group B than those in group A. The peak area of Ins and the Ins/Cr ratio in the visual cortex of monkey 4 in group B slightly increased. The peak area of Cho and the Cho/Cr ratio in the visual cortex of all monkeys in group B dramatically increased compared with group A. The peak area of Glx in the visual cortex of all monkeys in group B slightly increased compared with group A.

Conclusions

¹H-MRS could detect biochemical and metabolic changes in the visual cortex and therefore this technique can be used to provide valuable information for investigating the mechanisms of cross-modal plasticity of binocular blindness in a macaque monkey model.     

Recent developments in regenerative ophthalmology

Regenerative medicine(RM) is one of the most promising disciplines for advancements in modern medicine, and regenerative ophthalmology(RO) is one of the most active fields of regenerative medicine. This review aims to provide an overview of regenerative ophthalmology, including the range of tools and materials being used, and to describe its application in ophthalmologic subspecialties, with the exception of surgical implantation of artificial tissues or organs(e.g., contact lens, artificial cornea, intraocular lens, artificial retina, and bionic eyes) due to space limitations. In addition, current challenges and limitations of regenerative ophthalmology are discussed and future directions are highlighted.     

精料的蛋白质水平及能量浓度对亚成体大熊猫日粮消化率的影响

采用双因子交叉分组 (2× 2 )试验设计方案 ,选用 2只亚成体大熊猫进行 5期 (第 5期用常规日粮 )消化试验 ,考察精料的蛋白质水平与能量浓度对亚成体大熊猫日粮消化率的影响。结果表明 :精料蛋白质水平对粗蛋白、半纤维素、能量的消化率均产生显著影响 (P <0 0 5 ) ,对粗脂肪消化率产生极显著影响 (P <0 0 1) ,(相关系数分别为 0 7830、 0 76 18、 0 5 5 0 4、 0 6 72 3) ;精料能量浓度对无氮浸出物、中性洗涤纤维、能量的消化率产生显著影响 (P <0 0 5 ) ,对粗脂肪消化率产生极显著影响 (P <0 0 1) ,(相关系数分别为 0 5 5 6 9、0 6 0 4 7、0 5 0 5 2、 0 74 11)。对无氮浸出物、中性洗涤纤维、能量的消化率而言 ,该 2个因素互作效应显著 (P <0 0 5 )。1～ 4试验期 ,粗脂肪、半纤维素 ,1～ 5试验期 ,粗脂肪、半纤维素、中性洗涤纤维、纤维素、总能量等项消化率与 2个因素线性回归达到显著性水平 (α =0 0 5 ) (其中粗脂肪及 1～ 5期半纤维素达到极显著 ,α =0 0 1)。从多重比较结果看 ,除木质素外 ,各项消化率均以第 1期为最高 ,因此 ,日粮配方 1(CP2×GE2即CP 2 0 6 1%×GE 19 5 3MJ/kg)是优选配方     

Mitochondria-associated endoplasmic reticulum membranes dysfunction contributes to PARP-1-dependent cell death under oxidative stress in retinal precursor cells

Persistent poly (ADP-ribose) polymerase 1 (PARP-1) activation has proven detrimental and can lead to PARP-1-dependent cell death. Mitochondria-associated endoplasmic reticulum (ER) membranes (MAMs) serve as essential hubs for many biological pathways, such as autophagy and mitochondria fission and fusion. This study aimed to alleviate the effects of hydrogen peroxide (H₂O₂)-induced persistent PARP-1 activation and MAM dysregulation by the usage of a PARP-1 inhibitor. Results showed that receptor-interacting protein kinase (RIPK) 1 inhibitor (necrostatin-1) and PARP-1 inhibitor (olaparib) protected retinal precursor cells from H₂O₂-induced death, while a pan-caspase inhibitor (Z-VAD-FMK) failed to protect R28 cells. Olaparib also alleviated H₂O₂-induced MAM dysregulation, as evidenced by decreased VDAC1/ITPR3 interactions and reduced mitochondrial membrane potential collapse. Additionally, olaparib also inhibited H₂O₂-induced autophagy. Inhibiting autophagic flux increased MAM signaling under both normal and oxidative conditions. Furthermore, H₂O₂ treatment caused a reduction in the protein level of mitofusin-2 (MFN2) in a dose- and time-dependent manner. Mfn2 knockdown was found to further magnify MAM dysregulation and mitochondrial dysfunction under normal and oxidative conditions. Mfn2 overexpression surprisingly enhanced H₂O₂-induced MAM signaling and failed to rescue H₂O₂-induced mitochondrial dysfunction. These results indicate that MAMs probably serve as a membrane source for oxidative stress-associated autophagy. MAM dysregulation also contributed to H₂O₂-induced PARP-1-dependent cell death. However, more studies are required to decipher the link between the modulation of Mfn2 expression, changes in MAM integrity, and alterations in mitochondrial performances.     

华芬酶-1600对长颈鹿日粮营养物质消化率的影响

在长颈鹿日粮中添加精料量的 0 0‰、 0 8‰、 1 0‰、 1 2‰剂量华芬酶 - 16 0 0 ,采用分期试验法对 3只成年健康长颈鹿进行 4期消化试验。结果表明 ,添加外源酶后 ,长颈鹿对日粮干物质、粗蛋白、粗脂肪、粗纤维的消化率均明显提高 (P <0 0 5 ) ,尤其是粗纤维的消化率 ,以第Ⅳ期 (添加 1 2‰ )最为显著 (P <0 0 5 )。因此 ,推荐添加量为 1 2‰。