Functional and structural assessment of retinal sheet allograft transplantation in feline hereditary retinal degeneration

Purpose  To investigate whether sheets of fetal retinal allografts can integrate into the dystrophic Abyssinian cat retina with progressive rod cone degeneration.
Methods  Fetal retinal sheets (cat gestational day 42), incubated with BDNF microspheres, were transplanted to the subretinal space of four cats at an early disease stage. Cats were studied by fundus examinations, bilateral full-field flash ERGs, and indocyanine green and fluorescein angiograms up to 4 months following surgery. E42 donor and transplanted eyes were analyzed by histology and immunohistochemistry for retinal markers.
Results  Funduscopy and angiography showed good integration of the transplants in two of four cats, including extension of host blood vessels into the transplant and some scarring in the host. In these two, transplants were found in the subretinal space with laminated areas, with photoreceptor outer segments in normal contacts with the host retinal pigment epithelium. In some areas, transplants appeared to be well-integrated within the host neural retina. Neither of these two cats showed functional improvement in ERGs. In the other two cats, only remnants of donor tissue were left. Transplants stained for all investigated cellular markers. No PKC immunoreactivity was detected in the fetal donor retina at E42, but developed in the 4-month-old grafts.
Conclusions  Fetal sheet transplants can integrate well within a degenerating cat retina and develop good lamination of photoreceptors. Functional improvement was not demonstrated by ERG in cats with well-laminated grafts. Transplants need to be further evaluated in cat host retinas with a more advanced retinal degeneration using longer follow-up times.     

ULTRASONOGRAPHIC FEATURES OF DIFFUSE HEPATOCELLULAR DISORDERS IN DAIRY CATTLE

Ultrasonography of the liver was performed in 200 Holstein-Friesian dairy cattle using a 3.5 MHz transducer with a linear array electronic scanner. Liver samples were taken, processed and examined microscopically and the fat occupying rate was calculated. The hepatic ultrasonograms were evaluated according to the presence of bright pattern, dark pattern, deep attenuation, vascular blurring and blurring of edges. Of the 200 animals, 96 had a normal liver, 63 had hydropic degeneration of the liver, 37 had fatty infiltration of the liver, 3 had liver dystrophy and I had hepatic amyloidosis, diagnosed through histopathological examination. Amyloidosis was characterized by bright pattern and blurring of edges. Liver dystrophy had higher percentages of bright pattern and blurring of edges than normal liver. Hydropic degeneration had higher percentages of dark pattern and blurring of edges than normal liver. Fatty infiltration had higher percentages of bright pattern, deep attenuation, vascular blurring and blurring of edges than normal liver. The present results suggest that different ultrasonographic patterns can be observed in various diffuse hepatocellular disorders in dairy cattle     

青藏高原放牧高寒草甸主要温室气体通量及其主控因素研究

在青藏高原高寒草地不同放牧强度区设4个试验样地,分别为原生草甸(NM)、轻度退化草甸(LM)、中度退化草甸(MM)和重度退化草甸(HM),监测草地温室气体通量。结果表明:不同放牧强度对草地温室气体通量影响显著,放牧活动对高寒草甸的影响首先表现在植被上,而土壤环境的变化比较迟滞。通过逐步回归分析和因子拆分得知,草甸甲烷通量影响较大的环境因素为土壤紧实度和有机质,分别能解释44.6%和28.4%的总变异,CO2通量影响较大的环境因素为紧实度和生物量,分别能解释36.1%和32.8%的总变异,氧化亚氮通量影响较大的环境要素为紧实度和有机质,分别能解释50.1%和22.9%的总变异,家畜的践踏作用使退化草地紧实度增加,进而引起温室气体通量的改变,高寒草甸退化演替发展到重度退化阶段时释放大量温室气体。     

海北州天然草地退化沙化成因与对策

基于海北州天然草地退化沙化的事实,简要分析了退化沙化的表现和危害,重点阐述了区域天然草地退化沙化的多层次原因,提出了相应的应对策略和建议。分析表明：海北州天然草地退化沙化的直接原因为超载过牧和生物链遭到破坏,间接原因为牧业人口数量的增加和畜牧技术的应用,内在原因为高寒气候特点和复杂地形造成区域草地生态系统的脆弱性。提出3项对策建议：推行计划生育,增加教育投资,控制并逐步减少牧业人口;大力推行现代高效畜牧业发展模式,发展栽培草地,实施“以草定畜”;树立“不再破坏就是保护”的意识,开展天然草地的有限治理。     

高寒地区栽培牧草化感效应缓解初探

为研究探讨土壤微生物对化感效应的潜在作用,以高寒草地生态修复常用牧草为研究对象,通过室内生物学实验,测定种子发芽率及幼苗的苗高、根长和干重,计算分析化感综合效应。结果显示：以未灭菌土壤U100为基质的5种牧草种子发芽率均为最高,完全灭菌土壤U0的均为最低,不同比例未灭菌土壤U75,U50和U25则因牧草种子的不同而表现出不同差异;幼苗生长方面,‘青海’垂穗披碱草(Elymus nutans ‘Qinghai’)、‘同德’老芒麦(Elymus sibiricus ‘Tongde’)和‘青海’中华羊茅(Festuca sinensis Qinghai)幼苗苗高随灭菌土壤增加而减小;5种牧草幼苗的根长均在U100处理下最长;幼苗干重的变化趋势同苗高相似。未灭菌土壤对5种牧草的影响主要表现在根系生长和干重方面。研究证明在幼苗生长阶段土壤微生物对根系生长至关重要,土壤微生物能缓解化感效应提高种子发芽率,但对不同物种的影响存在差异。     

COMPARATIVE EVALUATION OF HYDROPIC DEGENERATION OF THE LIVER IN DAIRY CATTLE THROUGH BIOCHEMISTRY, ULTRASONOGRAPHY AND DIGITAL ANALYSIS

Ultrasonography of the liver of 181 Holstein-Friesian cows was performed and blood samples were collected for analysis. The hepatic ultrasonograms were evaluated and the echoes were analyzed digitally. After slaughter, liver specimens were taken and examined histopathologically. Of the 181 animals, 120 had a normal liver and 61 had hydropic degeneration of the liver, diagnosed through histopathologic examination. Diagnostic accuracy rates for hydropic degeneration were determined based on the following test positive conditions: a) for biochemical analysis—high levels of aspartate aminotransferase, alanine aminotransferase, total bilirubin and non-esterified fatty acids; b) for ultrasonography—presence of dark pattern and blurring of edges; and c) for digital analysis—low echo means at 1 cm and 3 cm from the hepatic surface. Digital analysis had the highest overall specificity, accuracy and positive predictive values for hydropic degeneration, followed by ultrasonography. The results suggest that ultrasonography and digital analysis of hepatic ultrasonograms can be used for diagnosis of hydropic degeneration of the liver in place of biochemical analysis.     

Proceedings of the 2013 Joint JSTP/NTP Satellite Symposium

The first joint Japanese Society of Toxicologic Pathology (JSTP) and National Toxicology Program (NTP) Satellite Symposium, entitled “Pathology Potpourri,” was held on January 29^th at Okura Frontier Hotel in Tsukuba, Ibaraki, Japan, in advance of the JSTP’s 29^th Annual Meeting. The goal of this Symposium was to present current diagnostic pathology or nomenclature issues to the toxicologic pathology community. This article presents summaries of the speakers’ presentations, including diagnostic or nomenclature issues that were presented, select images that were used for audience voting or discussion, and the voting results. Some lesions and topics covered during the symposium include: treatment-related atypical hepatocellular foci of cellular alteration in B6C3F1 mice; purulent ventriculoencephalitis in a young BALB/c mouse; a subcutaneous malignant schwannoma in a RccHan:WIST rat; spontaneous nasal septum hyalinosis/eosinophilic substance in B6C3F1 mice; a rare pancreatic ductal cell adenoma in a young Lewis rat; eosinophilic crystalline pneumonia in a transgenic mouse model; hyaline glomerulopathy in two female ddY mice; treatment-related intrahepatic erythrocytes in B6C3F1 mice; treatment-related subendothelial hepatocytes in B6C3F1 mice; spontaneous thyroid follicular cell vacuolar degeneration in a cynomolgus monkey; congenital hepatic fibrosis in a 1-year-old cat; a spontaneous adenocarcinoma of the middle ear in a young Crl:CD(SD) rat; and finally a series of cases illustrating some differences between cholangiofibrosis and cholangiocarcinoma in Sprague Dawley and F344 rats.     

F1代西瓜亲本选择对防止退化的效应

1989～1993年对F1代西瓜亲本在相同条件下进行了连继世代选择和不加选择的加代繁殖两种处理，结果表明：F1代亲本的连续选择能不断提高株系的亲和力，产量比未加选择的增产25．88％。经选择后，母本x－4株系可溶性固形物从10．11％增至11．43％，增长13．06％．父本N－2株系的可溶性固形物含量从7．3％增至8．8％，增长21．92％。F1代炭疽病的发病率和病情指数从89．44％，33．23下降到61．17％和11．63。F1代西瓜亲本连续选择可增加商品率和品质，防止亲本连年自交衰竭和F1代种子退化，并可延长双亲和F1的使用年限，增加单位面积产量，增强抗病性。     

丘陵岗地人工防护林退化成因分析

以桃江县人工防护林为研究对象,分析了导致林地退化的主要原因,包括管护措施不到位、造林技术缺陷、自然灾害侵害、生理老化、环境污染等。针对退化原因,提出了相应的改造措施。