Role of the ventromedial nucleus of the thalamus in motor behaviour—I. Effects of focal injections of drugs

An assortment of drugs was injected into one or both ventromedial nuclei of the thalamus, to see how these influenced stereotypy, locomotion and posture in spontaneously behaving and actively rotating rats. Unilateral intrathalamic muscimol promoted weak ipsiversive circling, while bilateral treatment gave catalepsy. Similar injections of 4-amino-hex-5-enoic acid, which inhibits γ-aminobutyrate metabolism, raised γ-aminobutyrate levels in the ventromedial nuclei more than three-fold yet had none of these behavioural effects. The indirectly acting γ-aminobutyrate agonists flurazepam and cis-1,3-aminocyclohexane car☐ylic acid had little effect on posture and locomotion and, like muscimol and 4-amino-hex-5-enoic acid, elicited only very weak stereotypies. Procaine behaved like the γ-aminobutyrate antagonist bicuculline, provoking vigorous locomotor hyperactivity and teeth chattering if given uni- or bilaterally. Pretreatment of one ventromedial nucleus with muscimol or 4-amino-hex-5-enoic acid, and to a lesser extent flurazepam or cis-1,3-aminocyclohexane car☐ylic acid, gave rise to pronounced ipsilateral asymmetries when combined with a large systemic dose of apomorphine. Contraversive rotations were initiated by unilateral stereotaxic injection of muscimol into the substantia nigra pars reticulata, or with apomorphine from the supersensitive striatum in unilaterally 6-hydroxydopamine lesioned rats. Drug treatments in the ipsilateral ventromedial nucleus showed a similar rank order of potency at inhibiting these circling behaviours, seemingly by reducing apomorphine-induced posture and muscimol-induced hypermotility. The suppression of circling by muscimol in these tests was highlighted by introducing the compound into the ventromedial nucleus at the height of circling activity. Both types of circling stimulus lost the capacity to increase locomotion, but still caused head turning and stereotypy in rats made cataleptic with bilateral ventromedial muscimol. Treating one ventromedial thalamus with muscimol greatly intensified any pre-existing posture directed towards that side, and vice versa.

These data suggest that the ventromedial nucleus is not involved with the expression of stereotyped behaviours, but can profoundly influence posture and locomotion, especially in the presence of some other motor stimulus. The recovery of circus movements in rats with impaired ventromedial nucleus function implies this nucleus is not essential for the execution of circling in these models.     

Effects of nigral application of muscimol on release of [3H]γ-aminobutyrate and on multi-unit activity in various cat thalamic nuclei

The release of [³H]γ-aminobutyrate (GABA) neosynthesized from [³H]glutamine was estimated in one substantia nigra and in the ipsilateral thalamus of halothane-anesthetized cats by perfusing a [³H]glutamine-enriched physiological medium through a push-pull cannula implanted in the two structures under investigation. After two hours of superfusion, muscimol (10^?6 M) was delivered through the nigral push-pull cannula for 50–60 min and local- and distal-evoked changes of [³H]GABA release were analyzed. In some experiments, changes of global neuronal activity induced by muscimol application were recorded in different thalamic nuclei, using a bipolar electrode. In a few of the above experiments, biochemical and electrophysiological determinations were simultaneously performed in the substantia nigra and the thalamus. The nigral application of muscimol (10^?6 M) induced locally an activation of the substantia nigra reticulata cells, as well as an increase in release of [³H]GABA.Distally, in the thalamus, two types of biochemical and electrophysiological responses were observed according to the localization of the tip of the push-pull cannula or the electrode. (1) An increased release of [³H]GABA and a depression of the global multi-unit cellular activity were obtained in the ventralis medialis-ventralis lateralis, the centralis lateralis and the paracentralis nuclei. These effects could reflect an activation of the GABAergic nigrothalamic neurons projecting to these different thalamic nuclei. (2) In contrast, in the medialis dorsalis paralamellar zone adjacent to the intralaminar nuclei of the thalamus, a decrease of [³H]GABA release and an activation of the multi-unit activity were obtained. These latter results may suggest either a polysynaptic response or the non-GABAergic nature of the nigrothalamic neurons afferent to the medialis dorsalis paralamellar zone.     

Nigral and cerebellar synaptic terminals in the intermediate and deep layers of the cat superior colliculus revealed by lesioning studies

The presence of degenerating nigral and cerebellar synaptic terminals in the intermediate and deep layers of the cat superior colliculus was demonstrated by electron microscopy following lesions of the substantia nigra or brachium conjunctivum. The superior colliculus was taken for analysis 4–5 days after operation. Nigral terminals underwent a dark type of degeneration following kainic acid lesion of the pars reticulata of the substantia nigra. The majority of nigral degenerating terminals and axons were found in the stratum griseum intermediate with a few in the stratum griseum profundum. Two kinds of cerebellar terminals were distinguished by general appearances such as size, type of synaptic contact and type of synaptic vesicle and by the pattern of degenerative changes following electrical lesion of the brachium conjunctivum. Large elongated synaptic terminals 4–7 μm in diameter, were found mainly in the stratum griseum profundum. They often had double termination with conventional dendrites and with vesicles containing dendrites. This kind of terminal had a filamentous type of degeneration. A second type of degenerating cerebellar terminal, characterized by an electron-lucent type of degeneration, was predominantly located in the stratum griseum intermediale. These terminals were circular, about 4 μm in diameter, and did not have synaptic contact with vesicle-containing profiles. The finding of the two types of degenerating terminal after lesion of the brachium conjunctivum can be considered as evidence of the coexistence of at least two kinds of cerebellar terminals in the superior colliculus. The presence of nigral and cerebellar terminals in the intermediate and deep layers of the superior colliculus implicates the involvement of the substantia nigra and cerebellum in control of collicular visuomotor function.     

Monoclonal antibody to a DNA-binding domain of p53 mimics charge structure of DNA: anti-idiotypes to the anti-p53 antibody are anti-DNA

Antibodies to DNA are important markers of various autoimmune diseases and can be pathogenic; however, their generation is not understood. We previously reported that anti-DNA antibodies could be induced in mice by idiotypic immunization to PAb-421, an antibody to a DNA-binding domain of p53. We now report that two monoclonal antibodies of moderate affinity (K(D) asymptotically equal to 10(-7)), raised from PAb-421-immunized mice, specifically recognized both PAb-421 and DNA. These antibodies feature multiple arginine residues in the antigen-binding site, a unique characteristic of disease-associated anti-DNA antibodies; nevertheless, these anti-DNA antibodies show specific complementarity to PAb-421 by competing with p53 for PAb-421 binding and recognize defined oligonucleotides with a specificity similar to that of p53. To study the structural basis for the cross-recognition of PAb-421 and DNA by the anti-DNA antibodies, we constructed computer models (fine-tuned by protein-protein docking) of PAb-421 and one of the monoclonal anti-DNA antibodies. The modeled structures manifested structural complementarity. Most notably, the modeled structure of PAb-421 resembled the structure of DNA by the positions of negatively charged groups and aromatic side chains. Thus, a protein molecule may mimic the structure of DNA and the elusive generation of anti-DNA antibodies could be explained by idiotypic immunity to a DNA-binding protein, like p53.     

低氧诱导因子-1α在视网膜母细胞瘤发生发展中作用的研究进展

视网膜母细胞瘤（ retinoblastoma ,Rb）是眼内常见恶性肿瘤之一,恶性程度高,危害大。传统的治疗方法破坏性强,预后不佳。低氧诱导因子－1α在Rb中高表达,影响肿瘤细胞的分化增殖及转移,参与血管生成拟态的生成,进而调控Rb的整个发生发展过程。本文将对低氧诱导因子－1α在Rb发生发展中的作用做一综述,以期为Rb的治疗开辟新的途径。     

Pathogen infections and primary biliary cholangitis

Primary biliary cholangitis (PBC) is a multi-factorial disease caused by the interaction of both genetic predisposition and environmental triggers. Bacterial infection has been investigated most intensively, both epidemiologically and experimentally, as a prime environmental aetiology in PBC. The association of recurrent history of urinary tract infection (UTI) with PBC has been frequently confirmed by several large-scale, case–control studies, despite variation in geographic area or case-finding methods. Escherichia coli is a predominant pathogen in most cases with UTI. Animal studies and molecular mimicry analysis between the human and E. coli E2 subunit of the 2-oxo-acid dehydrogenase complexes demonstrated that E. coli infection is a key factor in breaking immunological tolerance against the mitochondria, resulting in the production of anti-mitochondrial autoantibodies (AMA), the disease-specific autoantibodies of PBC. Novosphingobium aromaticivorans, a ubiquitous xenobiotic-metabolizing bacterium, is another candidate which may be involved in the aetiology of PBC. Meanwhile, improved environmental hygiene and increased prevalence of PBC, especially in males, may argue against the aetiological role of bacterial infection in PBC. Multiple mechanisms can result in the loss of tolerance to mitochondrial autoantigens in PBC; nonetheless, bacterial infection is probably one of the dominant pathways, especially in female patients. Notably, there is a rising prevalence of male patients with PBC. With increasing exposure to environmental xenobiotics in both genders, studies directed towards identifying the environmental culprit with systematically designed case–control studies are much needed to further determine the environmental factors and role of bacterial infections in PBC.     

Pathogens and autoimmune hepatitis

Autoimmune hepatitis (AIH) is a severe form of hepatitis resulting in the autoimmune-mediated destruction of the liver parenchyma. Whereas many of the immunopathogenic events have been elucidated and some of the drivers of the disease have been identified, little is known about the aetiology of the disease. There are certain risk factors, such as particular human leucocyte antigen (HLA) haplotypes, that enhance the susceptibility for AIH or influence the severity of the disease. However, as for many other autoimmune diseases, the mere presence of such risk factors does not warrant the occurrence of the disease. Not all individuals carrying risk factors develop AIH, and not all patients with AIH are carriers of high-risk alleles. Thus, additional environmental factors need to be considered as triggers for AIH. Environmental factors include diet, sunlight exposure, stress, medication and hygiene, as well as pathogen infections and vaccinations. This review discusses if pathogens should be considered as triggers for the initiation and/or propagation of AIH.     

Rheumatoid arthritis and enteric bacteria

Factors in the etiopathogenesis of rheumatoid arthritis (RA) include the genetic back-ground, environmental factors and perpetuation of the inflammatory process. This review focuses on enteric bacteria as initiating or perpetuating factors in the etiopathogenesis of RA. Based on the hypothesis that entrobacterial antigens that originated from intestinal flora induce rheumatoid inflammation in the joints, animal models of arthritis due toEnterobacteriaceae, studies on humoral and cellular responses to entrobacterial antigens in RA, etiology of RA involving both genetic and environmental factors, pathogenesis of rheumatoid inflammation accompanied by joint destruction, and clinical trials with basic therapeutic considerations are reviewed. The results of immunological studies on RA suggest that some patients with RA are sensitized to antigens common amongEnterobacteriaceae (bacterial outer membrane proteins of 35 and 38 kDa). A bacterial outer membrane protein of 38 kDa was identified as OmpC having amino acid homology (NYGVV) with HLA-DR4. This OmpC peptide elicited peripheral blood T cell proliferative responses in patients with RA. The presentation of this enterobacterial peptide by the RA-associated DR motif to CD4⁺ T cells could lead to initiation of disease. We now consider that in some patients, RA may be based on autoimmunity from molecular mimicry by entrobacterial antigens of HLA-DR4.     

桃叶珊瑚苷调控RhoA/ROCK 信号通路对胃癌MGC803 细胞上皮间质转化和血管生成拟态的影响

目的：探究桃叶珊瑚苷（AU）调控RhoA/ROCK信号通路对胃癌MGC803细胞上皮间质转化（EMT）进程和血管生成拟态（VM）形成的影响。方法：常规培养人胃癌MGC803细胞,将其随机分为对照组、AU-L组（20μmol/L AU）、AU-M组（40μmol/L AU）、AU-H组（80μmol/L AU）、AU-H+RhoA激活剂水仙环素（Nar）组（AU-H+Nar组,80μmol/L AU+30μmol/L Nar）。采用CCK-8法、Transwell实验、细胞划痕实验分别检测不同浓度AU对细胞增殖、迁移和侵袭的影响,三维细胞培养法观察不同浓度AU对细胞体外VM管腔结构形成的影响,WB法检测AU对各组细胞RhoA、ROCK、VM与EMT相关蛋白表达的影响。结果：与对照组相比,AU-M组、AU-H组MGC803细胞增殖率（48、72 h时）、细胞迁移率、细胞侵袭数目、VM管腔结构数,以及RhoA、ROCK1、N-cadherin、vimentin、VE-cadherin的蛋白表达均显著降低（均P<0.05）,E-cadherin表达显著升高（P<0.05）;同时,使...     

卵巢癌血管生成拟态形态学观察和基质金属蛋白酶表达

目的:在卵巢癌腹腔移植瘤模型中进行卵巢癌血管生成拟态的形态学观察并检测基质金属蛋白酶2(MMP2)的表达情况。方法:卵巢癌细胞SKOV3接种裸鼠腹腔,建立卵巢癌腹腔移植瘤模型,在同一张切片上以抗鼠CD34标记鼠血管内皮细胞,PAS染色行基底膜样结构标记。并应用免疫组化和RT-PCR方法比较MMP2在卵巢癌腹腔移植瘤中央和边缘区域组织的表达差异。结果:卵巢癌腹腔移植瘤中央区域可见卵巢癌细胞围成管状结构,中间可见红细胞,未见CD34阳性细胞出现,PAS阳性物质呈颗粒状弥散分布在卵巢癌细胞浆内,有的贴附在管腔内侧。免疫组化提示MMP2蛋白阳性表达率在肿瘤中央区域组织比肿瘤边缘区域明显增高,RT-PCR分析显示肿瘤组织中央区域MMP2表达与边缘区域相比有显著性差异。结论:卵巢癌细胞分泌PAS阳性物质,可能参与构建肿瘤的血管基质重塑。卵巢癌中央区域可见血管生成拟态,肿瘤中央区域MMP2表达高于肿瘤边缘区域,MMP2表达是否与卵巢癌血管生成拟态形成有关,仍需今后进一步研究。