Growth factors and their receptors in the olfactory system.

The olfactory epithelium is unique in the mammalian nervous system as it is a site of continual neurogenesis. Constant turnover of primary sensory neurons in the periphery results in continuous remodeling of neuronal circuits and synapses in the olfactory bulb throughout life. Most of the specific mechanisms and factors that control and modulate this process are not known. Recent studies suggest that growth factors, and their receptors, may play a crucial role in the development and continuous regeneration of olfactory neurons, i.e. particularly in neuronal proliferation, neurite outgrowth, fasciculation and synapse formation of the olfactory system. The potential role of the following factors and their receptors in different species are reviewed: Nerve growth factor (NGF); insulin-like growth factors (IGFs); fibroblast growth factors (FGFs); epidermal growth factor (EGF); transforming growth factor alpha (TGF alpha); amphiregulin (AR) and transforming growth factors beta (TGFs beta).     

Effects of fibroblasts derived from the olfactory bulb and nasal olfactory mucosa on proliferation of olfactory ensheathing cells harvested from the olfactory bulb

Olfactory ensheathing cells (OECs) have been reported to promote axonal regeneration when transplanted to rodent spinal cord injury models. OECs are available from the olfactory bulb (OB) and olfactory mucosa (OM). Although harvesting OECs from the OM is less traumatic, OECs originating from the OM are less proliferative than those from the OB (OB-OECs). One possible reason for this difference is coexisting fibroblasts. Here, we examined the effect of coculturing either fibroblasts from the OB (OB-Fibs) or fibroblasts from the OM (OM-Fibs) on the proliferation of OB-OECs. Proliferation of OB-OECs was significantly higher in 5:5 coculture with OB-Fibs and in 7:3 and 5:5 cocultures with OM-Fibs than without fibroblasts. These results indicated that coculture with both OB-Fibs and OM-Fibs promoted the proliferation of OB-OECs.     

Ultrastructural and histochemical properties of the olfactory system in the japanese jungle crow, Corvus macrorhynchos

Although it has been commonly believed that birds are more dependent on the vision and audition than the olfaction, recent studies indicate that the olfaction of birds is related to the reproductive, homing, and predatory behaviors. In an attempt to reveal the dependence on the olfactory system in crows, we examined the olfactory system of the Japanese jungle crow (Corvus macrorhynchos) by histological, ultrastructural, and lectin histochemical methods. The olfactory epithelium (OE) of the crow occupied remarkably a small area of the nasal cavity (NC) and had the histological and ultrastructural features like other birds. The olfactory bulb (OB) of the crow was remarkably small and did not possess the olfactory ventricle. The left and right halves of the OB were fused in many cases. In the lectin histochemistry, soybean agglutinin (SBA) and Vicia villosa agglutinin (VVA) stained a small number of the receptor cells (RCs) in the OE and the olfactory nerve layer (ONL) and glomerular layer (GL) on the dorsocaudal region of the OB. Phaseolus vulgaris agglutinin-E (PHA-E) stained several RCs in the OE and the ONL and GL on the ventral region of the OB. These results suggest that 1) the crow has less-developed olfactory system than other birds, and 2) the dedicated olfactory receptor cells project their axons to the specific regions of the OB in the crow.     

Some aspects of purinergic signaling in the ventricular system of porcine brain

Background

Numerous signaling pathways function in the brain ventricular system, including the most important - GABAergic, glutaminergic and dopaminergic signaling. Purinergic signalization system - comprising nucleotide receptors, nucleotidases, ATP and adenosine and their degradation products - are also present in the brain. However, the precise role of nucleotide signalling pathway in the ventricular system has been not elucidated so far. The aim of our research was the identification of all three elements of purinergic signaling pathway in the porcine brain ventricular system.

Results

Besides nucleotide receptors on the ependymocytes surface, we studied purines and pyrimidines in the CSF, including mechanisms of nucleotide signaling in the swine model (Sus scrofa domestica). The results indicate presence of G proteins coupled P2Y receptors on ependymocytes and also P2X receptors engaged in fast signal transmission. Additionally we found in CSF nucleotides and adenosine in the concentration sufficient to P receptors activation. These extracellular nucleotides are metabolised by adenylate kinase and nucleotidases from at least two families: NTPDases and NPPases. A low activity of these nucleotide metabolising enzymes maintains nucleotides concentration in ventricular system in micromolar range. ATP is degraded into adenosine and inosine.

Conclusions

Our results confirm the thesis about cross-talking between brain and ventricular system functioning in physiological as well as pathological conditions. The close interaction of brain and ventricular system may elicit changes in qualitative and quantitative composition of purines and pyrimidines in CSF. These changes can be dependent on the physiological state of brain, including pathological processes in CNS.     

一株鸭源H3N6亚型禽流感病毒遗传进化分析

从活禽交易市场健康鸭体内分离到一株H3N6亚型禽流感病毒,命名为A/Duck/Guangdong/E9/2012(H3N6),这是该亚型禽流感病毒在我国广东地区的首次分离报道.为分析其遗传进化特征,对该病毒全基因组序列进行了测定,进行了遗传进化分析.结果显示,其HA裂解位点附近的氨基酸序列为PEKQTR↓ GLF,只含有1个碱性氨基酸,符合低致病性禽流感病毒的HA裂解位点氨基酸序列的分子特征;其HA基因与2011年蒙古国分离的鸭源A/Duck/Mongolia/OIE-7457/2011(H3N5)禽流感病毒的HA基因同源性最高,其NA基因与2011年蒙古国分离的鸭源A/Duck/Mongolia/OIE-7438/2011(H4N6)禽流感病毒的NA基因同源性最高.全基因组分子遗传进化分析结果显示,其8个基因均属于欧亚谱系的禽源进化分支.     

猪流行性腹泻病毒SD2014株全基因组序列测定与遗传演化分析

为分析猪流行性腹泻病毒(PEDV)在国内的流行及变异情况,对2014年在山东省某猪场流行的PEDV毒株SD2014进行全基因组测序,并与国内外代表毒株进行序列比对、同源性分析和遗传演化分析。结果表明,SD2014毒株全长28,036 nt(除去Poly A)。遗传演化分析显示该毒株与美国分离株OH851以及我国2010年后分离的变异毒株属于同一分支。通过对S基因和ORF3序列进行对比,发现SD2014与我国早期分离株BJ-2011-1变异位点相似,且与欧美毒株和疫苗株(CV777)差异明显。提示自2010年PED暴发后,与疫苗株差异较大的变异株仍在国内流行,该病防控形势依然严峻。     

Basic husbandry and clinical assessment of the amphibian patient.

The veterinarian presented with an amphibian patient must be prepared to assess both the animal's medical condition and its husbandry record; good health is inextricably linked to proper care and diet. This article provides the clinician with guidelines for maintaining amphibians in captivity, including information on climate control and lighting, housing and cage enrichment, and nutrition. The article also covers questions to ask when taking a history, methods of restraint, and practical advice on the equipment and techniques used to conduct a complete physical examination of the amphibian patient.     

用SSR标记进行家蚕日系品种资源指纹图谱的构建及亲缘关系分析

利用微卫星标记(SSR),在DNA分子水平上构建了家蚕84个日本系统二化性品种和9个多化性品种共94个材料的指纹图谱。用68对SSR引物扩增出705条有效带,最多的一对引物有31个等位片段,最少的仅有2个,平均每个引物10.4个。根据每个品种的指纹特征,利用UPGMA聚类法对结果进行分析,发现其SSR标记不但具有系统特异性,而且具有品种特异性,能够证明二化性日系品种与多化性品种在进化上属于显著差异的两个类群,较准确地将各品种按亲缘关系远近聚类。     

Simultaneous detection and subtyping of porcine endogenous retroviruses proviral DNA using the dual priming oligonucleotide system

The purpose of this study was to develop a multiplex PCR that can detect porcine endogenous retrovirus (PERV) proviral genes (pol, envA, envB, envC) and porcine mitochondrial DNA, using a dual priming oligonucleotide (DPO) system. The primer specifically detected the PERV proviral genes pol, envA, envB, envC, and porcine mitochondrial DNA only in samples of pig origin. The sensitivity of the primer was demonstrated by simultaneous amplification of all 5 target genes in as little as 10 pg of pig DNA containing PERV proviral genes and mitochondrial DNA. The multiplex PCR, when applied to field samples, simultaneously and successfully amplified PERV proviral genes from liver, blood and hair root samples. Thus, the multiplex PCR developed in the current study using DPO-based primers is a rapid, sensitive and specific assay for the detection and subtyping of PERV proviral genes.     

华南地区三株新城疫地方强毒株的序列测定及其系统发育分析

用设计的特异性引物，通过一步法RT-PCR扩增出5个毒株的897bp片段，对其中的3株病毒cDNA分析表明：各毒株的半胱胺酸位点和个数及糖化位点基本没有改变。各毒株在抗原决定簇氨基酸位点HN基因346-353处的碱基突变甚多，且氨基酸也出现了部分的突变。针对HN基因897bp片段构建了相应的系统发育树，系统发育分析表明：中国（华南）地区NDV各毒株与欧美国家的Ⅱ至Ⅴ基因群明显分离，遗传规律较远；NDV-WS1和NDV-HY与台湾省NDV各毒株归属为一组，与中国毒株的遗传距离较近，均属新近出现的基因型Ⅶ型，NDⅦ型在远东和西欧（Ⅶb）和及中东和南非（Ⅶa）广泛存在，可能形成了ND的第4次大流行。这些一方面说明NDV的变异可能已突破种源屏障，在鸡与鹅之间进行相互传播；另一方面说明中国古老的NDV毒株仍然持续存在，并逐渐向强毒株突变，与其他新出现的基因型毒株“共循环“。     

Comparison of cell populations derived from canine olfactory bulb and olfactory mucosal cultures

OBJECTIVE: To evaluate the numbers and proportions of olfactory ensheathing cells (OECs) in cell cultures derived from the olfactory bulb (OB) and olfactory mucosa of dogs. ANIMALS: 7 dogs. PROCEDURES: OB tissue and olfactory mucosa from the nasal cavity and frontal sinus were obtained from euthanatized dogs and prepared for cell culture. At 7, 14, and 21 days of culture in vitro, numbers and proportions of OECs, astrocytes, and fibroblasts were determined via immunocytochemistry. Antibody against the low-affinity nerve growth factor receptor p75 was used to identify OECs, antibody against glial fibrillary acidic protein was used to identify astrocytes, and antibody against fibronectin was used to identify fibroblasts. RESULTS: Cultured OECs derived from the olfactory mucosa of the nasal cavity and frontal sinus had similar characteristics. However, whereas OECs in the OB cell cultures constituted approximately 50% of the cells at 7 days and approximately 75% at 21 days the proportion of OECs in cultures derived from both mucosal types was much lower, with approximately 40% OECs at 7 days and approximately 25% at 21 days. Analysis of OEC numbers revealed that these changes were accompanied by corresponding decreases and increases in the population of cells with fibronectin receptors. CONCLUSIONS AND CLINICAL RELEVANCE: Although olfactory mucosal cell cultures yielded a sufficient number of OECs for spinal cord transplantation procedures in dogs, modification of culture conditions would be required to ensure that the derived cell population contained a sufficient proportion of OECs.     

山东沂源硬蜱携带无形体的调查及进化分析

为了解山东省沂源县境内硬蜱携带无形体的流行及菌株变异情况,于2015年5月~7月从该地区山羊体表共分离到54份126只不同生活史阶段的长角血蜱,分组研磨提取DNA后,利用套式PCR扩增无形体的16SrRNA(ribosomal RNA)基因片段并测序及进行序列的遗传进化分析。结果显示,54份样品PCR阳性扩增率为48.1%;序列分析表明,该地区无形体存在6个变异株,分为4类,其中3类与该地区以往报道的嗜吞噬细胞无形体序列保持密切的遗传关系,还有1类与日本长角血蜱体内检出的牛无形体序列遗传关系较近。由此可见,山东沂源地区长角血蜱存在较高的嗜吞噬细胞无形体感染率,并且变异株较多;应该加强该地区对人粒细胞无形体病的宣传力度,防止该病大规模暴发。