Effects of lead on red blood cell membrane proteins

Summary The effects of lead on red blood cell (RBC) membrane proteins were studied in two groups of workers with different lead exposure levels: Group 1 (6 subjects employed in a battery plant) with a mean blood lead of 40.1 (SD = 3.7) g/100 ml; Group II(5 workers employed in different industries) with a mean blood lead of 60.6 (SD = 8.0) g/100 ml, compared with a control group with mean blood lead of 15.6 (SD = 9.3) g/100 ml. The analysis of RBC membrane polypeptides was carried out by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and by using a densitometer for percentage measurement of the bands corresponding to protein fractions. The results show a very significant decrease in Band 3 (anion channel) and 4.1 in more exposed workers (Group II) only. The effects of lead on RBC membrane proteins seem to be evident at blood-lead levels higher (> 50 g/100 ml) than those previously reported in literature. These results confirm the effects of lead on membrane proteins, even if the exact mechanism, particularly the influence of proteolysis and the meaning of the interference, still needs to be investigated thoroughly.     

水泡绦虫体壁的超微结构与功能

本文通过透射电镜观察水泡绦虫成虫体壁的结构,发现成虫体壁密布微毛并具纤毛,微毛顶端棘突系条状结晶蛋白。皮层基质区有许多液泡,内含颗粒或脂滴及不定形的基质。皮下层为有核细胞区,富有细胞器,实质中有较多电子致密细胞和核周体,并向皮层发出大小不等的胞质通道,构成一个片层状的管网结构,显示体壁能取代肠管的特殊功能。     

A computer-enhanced comparative study of brain region polypeptides and proteins by two-dimensional gel electrophoresis

A reproducible and quantitative strategy for identifying tissue-specific proteins of the central nervous system is described. The methods include a simple extraction procedure, two-dimensional polyacrylamide gel electrophoresis (2-DGE), silver staining, and computerized analysis. Acetic acid protein extractions of brain regions from three groups of male Sprague—Dawley rats were compared by computer analysis using 2-DGE with GELCODE silver staining. Protein spot mapping and characterizations of molecular weight and pI were compiled for the pineal gland, retina, hypothalamus and cerebral cortex. Regionally specific protein spots were identified using the Visage System (BioImage) for data acquisition and a new set of algorithms (University of Arizona) for assigning isoelectric point (pI) and molecular weight determinations, spot matching and selection of unique spots. Seventeen newly identified acidic proteins are unique to the pineal gland. Some others are also common to the retina but not in other regions examined. Further study of these and other regionally specific proteins are of particular interest under conditions which alter biological or disease mechanisms.     

唾液酸糖表位类人源化N-糖基化修饰治疗性重组蛋白的研究进展

唾液酸化N-糖基化修饰重组蛋白能提高治疗性蛋白的理化性质,如延长半衰期、增强组织穿透性以及抑制炎症反应等。但迄今为止糖蛋白的N-糖基化修饰效率和唾液酸化效率都很难达到100%,这导致了唾液酸修饰糖基化重组蛋白的均质化、规模化生产非常困难。因而提高类人源化N-糖基化修饰治疗性重组蛋白的均质性仍是目前糖蛋白药物研发任务之一。该文围绕提高唾液酸糖表位N-糖基化修饰治疗性重组蛋白效率的方法及均质化类人源化唾液酸糖表位治疗性重组蛋白的生产途径展开综述。     

The synaptology of parvalbumin-immunoreactive neurons in the primate prefrontal cortex.

Electron microscopy and immunocytochemistry with a monoclonal antibody against parvalbumin (PV) were combined to analyze the distribution and morphology of PV-immunoreactive (PV-IR) neurons and the synaptology of PV-IR processes in the principal sulcus of the macaque prefrontal cortex. Parvalbumin-IR neurons are present in layers II-VI of the macaque principal sulcus (Walker's area 46) and are concentrated in a band centered around layer IV. PV-IR cells are exclusively non-pyramidal in shape and are morphologically heterogeneous with soma sizes ranging from less than 10 microns to greater than 20 microns. Well-labeled neurons that could be classified on the basis of soma size and dendritic configuration resembled large basket and chandelier cells. A novel finding is that supragranular PV-IR neurons exhibit dendritic patterns with predominantly vertical orientations, whereas infragranular cells exhibit mostly horizontal or oblique dendritic orientations. PV-IR cells within layer IV exhibit a mixture of dendritic arrangements. Vertical rows of PV-IR puncta, 15-30 microns in length, resembling the "cartridges" of chandelier cell axons were most dense in layers II, superficial III, and the granular layer IV but were not observed in the infragranular layers. Cartridges were often present beneath unlabeled, presumed pyramidal cells. PV-IR puncta also formed pericellular nests around pyramidal cell somata and proximal dendrites, suggestive of basket cell innervation. PV-IR axons were occasionally observed in the white matter underlying the principal sulcus. Electron microscopic analysis revealed that PV-IR somata and dendrites are densely innervated by nonimmunoreactive terminals forming asymmetric (Gray type I) synapses as well as by fewer terminals forming symmetric (Gray type II) synapses. The majority of terminals forming symmetric synapses with PV-IR post-synaptic structures were not immunolabeled; however, some of these boutons did contain PV-immunoreactivity. PV-IR boutons exclusively form symmetric synapses and heavily innervate layer II/III pyramidal cells. PV-IR axon cartridges formed numerous axo-axonic synapses with the axon initial segments of pyramidal cells 15-20 microns beneath the axon hillock and also terminated on large axonal spines of the initial segment. Furthermore, we failed to observe a mixture of PV-immunoreactive and non-immunoreactive boutons composing a single axon cartridge. Pyramidal cell somata and proximal dendrites were also heavily innervated by PV-IR boutons forming symmetric synapses, again, consistent with basket cell innervation. In addition, PV-IR axon terminals frequently formed symmetric synapses with dendritic shafts and spines of unidentified neurons.(ABSTRACT TRUNCATED AT 400 WORDS)     

Differential Calcium Binding Protein Immunoreactivity Distinguishes Classes of Relay Neurons in Monkey Thalamic Nuclei

The distributions of neurons displaying immunoreactivity for two calcium binding proteins, parvalbumin and 28Kd calbindin, were studied in the thalamus of M. fascicularis. Colocalization experiments were carried out to determine the extent to which parvalbumin- and calbindin-like immunoreactivity was found in the same cells and the extent to which either was localized in GABAergic interneurons. Anterograde and retrograde tracing experiments involving the fluorescent tracer, fast blue, were also used to determine that cells expressing the calcium binding proteins projected upon the cerebral cortex. In the dorsal thalamus, nuclei are distinguished by different patterns of parvalbumin-like and calbindin-like immunoreactivity. In certain nuclei, for example the lateral dorsal and anterior pulvinar, neurons express immunoreactivity for only one of the calcium binding proteins. In others, neurons in different layers, for example the dorsal lateral geniculate nucleus, or in different compartments, for example the intralaminar nuclei, express immunoreactivity for either parvalbumin or calbindin; in other nuclei, for example the ventral group, neurons are mixed and immunoreactivity for parvalbumin and calbindin is commonly colocalized. In the ventral thalamus and epithalamus, similar patterns are observed. Colocalization of parvalbumin- and GABA-immunoreactivity is found in all cells of the reticular nucleus but only in certain cells in selected nuclei of the dorsal thalamus, namely the dorsal lateral geniculate and magnocellular medial geniculate. No calbindin-positive cells are also GABA-positive. Most parvalbumin and/or calbindin positive cells in the dorsal thalamus project to the cerebral cortex, as indicated by the retrograde tracing studies, and many parvalbumin positive fibres entering the cerebral cortex could also be shown to contain fast blue anterogradely transported from a thalamic injection. Most of the major sensory and motor pathways entering the dorsal thalamus express parvalbumin immunoreactivity. The optic tract also expresses calbindin immunoreactivity but most other calbindin positive fibres entering the thalamus ascend in the midbrain tegmentum. The differential distributions of parvalbumin and calbindin implied by these results suggest that thalamic cells belonging to different functional systems and projecting differentially upon the cerebral cortex can be distinguished by differential expression of these or closely related calcium binding proteins. This may yield clues to their differential responsivity to afferent driving.     

不同来源潜伏膜蛋白1基因转染对鼻咽癌CNE1细胞生长的影响

目的:探讨不同来源的EB病毒潜伏膜蛋白1(LMP1)基因转染对人高分化鼻咽癌(NPC)细胞系CNE1生长的影响。方法:采用脂质体介导法分别将含有来源于B95-8淋巴细胞标准株的LMP1基因(B95-8-LMP1)和来源于NPC组织的LMP1基因(CAO-LMP1)的质粒转染CNE1;RT-PCR和蛋白印迹法分别鉴定LMP1mRNA和蛋白表达;结晶紫法、流式细胞术和平板克隆形成法测定不同来源的LMP1对CNE1生长特性的影响。结果:成功建立稳定表达不同来源LMP1的CNE1细胞系。两种不同来源的LMP1均可促进CNE1细胞的生长(P<0.01);CAO-LMP1比B95-8-LMP1具有更强促进CNE1生长的作用(P<0.01)。结论:不同来源LMP1对CNE1的体外生长均有促进作用,CAO-LMP1比B95-8-LMP1具有更强的促增殖能力。     

Identification of GRASP-1 as a novel 97 kDa autoantigen localized to endosomes

We have identified an autoantigen that is recognized by antibodies from an 18-year-old female with a history of recurrent infections who later in her clinical course developed Raynaud's phenomenon and telangiectasias. By indirect immunofluorescence (IIF), the index serum produced a unique cytoplasmic discrete speckled (CDS) staining pattern that partially colocalized with early endosome antigen 1 (EEA1) but not Golgi complex or other cytoplasmic organelles in HEp-2 cells. When HEp-2 cells were treated with 0.1 N HCl, the cytoplasmic speckled staining of the index serum was markedly decreased, suggesting that the reactive antigen was soluble. Western blot analysis showed a reactive approximately 97 kDa protein in a saline soluble protein preparation from HeLa cells. Mass spectrometric analysis of the excised 97 kDa band that was immunoprecipitated from HeLa cell extracts identified GRASP-1 as a possible target. The index serum and anti-GRASP-1 antibodies colocalized to structures in the cytoplasm of HEp-2 cells. Synthetic peptides representing the full-length GRASP-1 protein were used to identify reactive epitopes. Like many other cytoplasmic autoantigens, GRASP-1 has numerous coiled-coil domains throughout the protein with the exception of short segments at the amino and carboxyl terminus.     

人白细胞介素12在哺乳动物细胞中的稳定表达及其生物活性的研究

目的采用遗传基因工程方法获得具有生物活性的人白细胞介素12,探索其治疗肿瘤和慢性肝炎的可行性。方法采用已克隆的国人IL-12基因序列,利用内部核糖体切入位点(IRES)完成IL-12P35、P40双亚基共表达载体的构建,通过转染CHODHFR缺陷细胞,双抗夹心ELISA法筛选阳性克隆,MTX加压扩增,PCR检测其基因整合,T淋巴细胞增殖和诱生γ干扰素实验检测其生物活性。结果获得了稳定高效表达人IL-12的工程细胞系,表达产物为70×103左右的糖蛋白。结论本研究得到的基因重组人IL-12具有良好的生物活性,有强的诱导产生γ干扰素的能力和诱导活化T淋巴细胞增殖能力。