骨髓间充质干细胞衍生的精原干细胞

近年来精原干细胞(spermatogonial stem cells,SSC)研究有两个具有重要意义的研究进展,一个进展是从新生小鼠[1]和成年小鼠睾丸[2]生殖细胞通过分离、基因分选、培养的SSC在胚胎干细胞(embryonic stem cells,ESC)培养条件下获得ESC特征,在离体条件下具有自发形成3个胚层的分化能力,在皮下注射这些细胞至免疫缺损小鼠,可以形成畸胎瘤;另一个进展是从骨髓间充质干细胞(bone marrow mesenchymal stem cells,BMSC)在离体培养条件下,通过基因挑选和改变培养条件可以衍生出具有精原干细胞和精原细胞分子特征的生殖细胞[3].     

骨髓基质干细胞分化为心肌细胞的研究进展

骨髓基质干细胞在适当的诱导剂诱导下可分化为心肌细胞,出现心肌细胞表型,还表达功能性受体。在心肌微环境中,也可分化为心肌细胞。但其分化机制尚不清楚。也有研究认为骨髓基质干细胞不能分化为心肌细胞,尚需对骨髓基质干细胞分化为心肌细胞的机制进行深入研究。     

胚胎干细胞定向诱导分化为心肌细胞进展

在个体发育过程中，通常把那些具有自我复制能力并能在一定条件下分化形成一种以上类型细胞的多潜能细胞称为干细胞。根据其发育阶段，干细胞可分为胚胎干细胞和成体干细胞。由于胚胎干细胞具有在体外培养下保持未分化状态的增殖能力及分化为多种细胞类型的潜能，使之成为一种研究哺乳动物细胞分化、组织形成过程的基本体系，以及临床移植治疗的新的细胞来源。人们利用胚胎干细胞建立了各种体外分化模型，本文将概述现今对胚胎干细胞定向诱导分化为心肌细胞方面的主要进展和趋势。     

造血干细胞的可塑性及临床应用

干细胞是一类具有自我复制和多分化潜能的细胞 ,根据其发育阶段不同 ,分为胚胎干细胞和成体干细胞。胚胎干细胞具有多分化潜能 ;而成体干细胞的分化潜能则较为局限 ,只能定向分化为特化细胞。但新近的研究表明 ,成体干细胞在一定条件下可分化为与其所在组织不同的其他组织类型细胞 ,这种干细胞的可塑性被称为成体干细胞的横向分化(ｔｒａｎｓｄｉｆｆｅｒｅｎｔｉａｔｉｏｎ)。其中造血干细胞 (ｈｅｍａｔｏｐｏｉｅｔｉｃｓｔｅｍｃｅｌｌｓ,ＨＳＣ)作为人们认识最深入 ,其临床应用也最为广泛的一类成体干细胞 ,目前已成为成体干细胞可塑性…     

骨髓基质干细胞向神经细胞诱导分化及其机制的研究进展

骨髓基质干细胞是一种存在于骨髓间质中具备多向分化潜能的成体干细胞,其不仅能分化为中胚层起源的骨、软骨和脂肪细胞,还可以在特定条件下诱导分化为神经外胚层起源的神经细胞。主要对骨髓基质干细胞向神经细胞诱导分化及其机制的研究进展作一综述。     

小鼠胚胎大脑皮质与中脑神经干细胞培养与分化比较的研究

目的比较小鼠胚胎脑皮质与中脑来源的神经干细胞在培养与分化方面的差异，为更好的研究和利用神经干细胞提供实验依据。方法无菌条件下分别分离鼠胚大脑皮质与腹侧中脑，经胰酶消化及机械吹打成单细胞后接种于含有B27、bFGF的DMEM／F12培养基，培养扩增；倒置显微镜观察比较生长状况；机械方法传代；10％血清接种分化；免疫荧光细胞化学方法染色鉴定神经干细胞及其子代细胞的分化方向，并作比较。结果小鼠胚胎脑皮质与中脑均存在神经干细胞，其免疫细胞化学鉴定均呈Nestin阳性，并都能分化为神经元和胶质细胞；但皮质部位所含神经干细胞明显多于中脑，也更宜成球；有血清条件下分化，皮质神经干细胞未见分化为酪氨酸羟化酶（TH）阳性神经元；中脑神经干细胞则可少量分化为TH阳性神经元结论同样条件下皮质神经干细胞比中脑神经干细胞更易增殖与培养，两者在有血清条件下分化为TH阳性神经元能力方面有差异。     

大鼠胚胎脑和脊髓神经干细胞分化特性比较

体外分离大鼠胚胎脑和脊髓神经干细胞,经培养传代后,撤除生长因子(bFGF和EGF)并给予 1%胎牛血清促其自然分化,然后比较两者的分化规律,以及传代次数对分化的影响。结果发现:在完全相同的培养条件下,来源于脑和脊髓的神经干细胞均可分化为神经元、少突胶质细胞和星形胶质细胞,但两者分化为神经元的能力均随细胞体外传代次数的增加而显著下降 (P<0. 05);此外,脑来源的神经干细胞分化为神经元的能力远高于脊髓来源的神经干细胞 (P<0. 01)。提示,来自中枢神经系统不同部位的神经干细胞在分化潜力上存在差别,体外传代会影响神经干细胞的分化能力。     

微环境调控毛囊干细胞增殖与分化的研究进展(综述)

隆突部的毛囊干细胞具有多分化潜能,能够分化为毛发中各型细胞、皮脂腺和表皮。毛囊干细胞“居住”的隆突部是神经末梢和毛细血管汇集的地方,为干细胞维持其自身稳定和接受信号传导提供了良好的微环境。微环境为保持干细胞自我更新和不分化的特性提供了场所。同时,在外界的刺激下细胞与细胞、细胞与细胞外基质及细胞内部的信号改变调控干细胞的增殖与分化。     

微重力对干细胞增殖分化影响的研究进展

微重力环境会影响干细胞的生长、增殖和分化。既往的部分研究表明,微重力环境下培养的间充质干细胞的生长速度较正常重力条件下培养更快,其原因可能是细胞团体积的增大。但是有研究指出微重力能够通过影响细胞周期抑制间充质干细胞增殖。在分化方面,微重力能够抑制间充质干细胞的成骨分化,促进其成脂肪分化,但是对其成软骨分化影响仍存争议。有研究者对微重力培养的间充质干细胞进行基因测序提示其成骨分化相关基因表达降低,同时伴有成脂肪分化的基因表达增高。微重力可能通过整合素/丝裂原活化蛋白激酶和PPAR-这两条信号通路抑制干细胞成骨分化作用,而微重力如何影响成软骨分化以及成脂分化的机制仍缺乏相关研究。同时,微重力能够有效地维持间充质干细胞的多能性和自我更新能力。微重力对于间充质干细胞的影响为组织工程的进一步发展提供了探索依据。     

体内诱导多能干细胞与机体的损伤修复及再生

细胞单向分化的假说在近年来受到挑战,越来越多的证据表明,高度分化的细胞可以在一定条件下转化为干细胞。而近来发现了两例小鼠体内由机体损伤干细胞缺失引起的高度分化细胞去分化形成干细胞的证据。这表明,哺乳动物可以不依赖外源干细胞的导入,而是由自体细胞的去分化成为多能性干细胞、增殖与再分化而起到修复损伤的作用。对于自体去分化再生机制的探究可能会引起一些具有挑战性的观念,这对于损伤修复,治疗肿瘤和众多难愈疾病有着重要的理论意义和极大的应用前景。     

Schizophrenia in a North Swedish geographical isolate, 1900–1977. Epidemiology, genetics and biochemistry

Over 200 schizophrenic patients belonging to three major and interrelated pedigree complexes have been investigated over the past 30 years in a North Swedish geographically isolated population, presently numbering about 6,000. An intensive investigation of a number of biochemical correlates and genetic markers in a few selected families belonging to one of the major pedigrees has indicated new strategies for the current research program.
Schizophrenia, as defined operationally, is significantly associated with decreased activities of two enzymes (1) blood platelet monoamine oxidase, (2) plasma dopamine-β-hydroxylase, and (3) with the genetic marker Gc² (group specific antigen). Both enzymes are subject to genetic variation. A positive score for linkage between schizophrenia and low plasma DBH activity has been calculated, but, so far, available data are insufficient for discrimination between linkage and partial contribution of genetically controlled low plasma DBH to the pathogenesis of the disease. Alternatively, both mechanisms could be involved.
As a model for continued research, schizophrenia is explained as based on a double dominant-recessive genotype (Aabb), representing a vulnerability which in about 50 % of cases develops into clinical schizophrenia. It is suggested that the dominant mutation (A) operates on or affects MAO activity, and that the recessive genotype (bb) is instrumental in low variates of DBH activity and very likely such variates within the normal range of physiological variation. Moreover, it is suggested that the combined effects of MAO- and DBH-reduced efficiency on the metabolism of e.g. dopamine could be an essential pathogenic mechanism for the schizophrenic illness which is segregating in this population.     

HLA in North Colombia Chimila Amerindians

HLA-A,-B,-C,-DRB1 and -DQB1 alleles have been studied in Chimila Amerindians from Sabana de San Angel (North Colombian Coast) by using high resolution molecular typing. A frequent extended haplotype was found:HLA-A*24:02-B*51:10-C*15:02-BRB1*04:07-DQB1*03:02 (28.7%) which has also been described in Amerinndian Mayos Mexican population (Mexico, California Gulf, Pacific Ocean). Other haplotypes had already been found in Amerindians from Mexico (Pacific and Atlantic Coast), Peru (highlands and Amazon Basin), Bolivia and North USA. A geographic pattern according to HLA allele or haplotype frequencies is lacking in Amerindians, as already known. Also, five new extended haplotypes were found in Chimila Amerindians. Their HLA-A*24:02 high frequencies characteristic is shared with aboriginal populations of Taiwan; also, HLA-C*01:02 high frequencies are found in New Zealand Maoris, New Caledonians and Kimberly Aborigines from Australia. Finally, this study may show a model of evolutionary factors acting and rising one HLA allele frequency (-A*24:02), but not in others that belong to the same or different HLA loci.     

The universal muscular chamber. A basic unit of the genitourinary, cardiovascular, gastro-intestinal, skeletal, cutaneous, respiratory and other systems, endocameral hypertension; and spasm, the key to their idiopathic diseases and arthropathies

Starting with the integument, we see many organs are contractile sacs or multiples thereof, which tubes or bags constitute the major part of the entire body. Recognition of this basic unit and its characteristics sheds new light, individually and collectively, on many disorders previously considered unrelated. Muscular tears and perforations develop in the walls of these chambers, being no way peculiar to those organs, wherein, hydrochloric acid occurs. So, it is not necessary to explain the absence of excessive acid from patients who exhibit holes in the gastric, uterine, aortic, duodenal, rectal, pulmonary, retina, and other walls. Muscle, not acid is the great common factor relating idiopathic disorders in the gastrointestinal tract to each other and to similar diseases in other systems. When the units are linked together, the lesions tend to appear as arthropathies, i.e. at the joints. Rephrasing common-place observations, frees us from conventional, conceptual cul-de-sacs. An observation is only as good as its interpretation, so all possibilities must be considered, otherwise, we will remain blinded by our misconceptions.     

Der Einfluß von Nahrungsmitteln und Rauchen auf die klinisch-chemische Diagnostik von Phäochromozytom,Neuroblastom und Karzinoid-Syndrom

Zusammenfassung Der Einfluß von verschiedenen Nahrungsmitteln auf Methoden zur Bestimmung von Adrenalin (AD), Noradrenalin (NA), Vanillinmandelsäure (VMS), Metanephrinen (MN), Homovanillinsäure (HVS) und 5-Hydroxyindolessigsäure (5-HIE) im 24 h-Harn zur Diagnose des Phäochromozytoms bzw. Karzinoid-Syndroms wurde untersucht. Die in die Untersuchung einbezogenen Nahrungsmittel waren: Tee, Kaffee, Mandeln, Ananas, Käse, Walnüsse, Vanillepudding, Bananen, Tomaten und Milchschokolade. Außerdem wurde der Einfluß des Zigarettenrauchens auf die Bestimmung von AD, NA, VMS und MN untersucht.Walnüsse führten zu einer starken Erhöhung der 5-HIE-Ausscheidung. Bananen erhöhten die Ausscheidung von AD, NA, VMS, MN und 5-HIE. Kaffee und Ananas bewirkten eine geringe Zunahme der MN-Werte. Rauchen von 20–30 Zigaretten/Tag beeinflußte keine der vier Variablen.Wenn die beschriebenen Methoden benutzt werden, sollte lediglich auf den Verzehr von Bananen und Walnüssen vor und während der Harnsammelperioden verzichtet werden, da die oberen Normgrenzen im Harn überschritten werden könnten. Ein Verzicht auf Kaffee und Ananas in normalen Mengen ist nicht erforderlich. Es besteht kein Anlaß, weiterhin die bisherigen umfangreichen Restriktionen der übrigen Nahrungsmittel beizubehalten.     

A comparative study of the effects of dimebon,obsidan, finoptin,and cordaron on the functional state of ischemic focus and size of necrotic zone in experimental myocardial infarction

Dimebon, an antihistamine agent, exerts a moderate antianginal effect, improving the function of ischemic focus in the myocardium and decreasing the necrotic zone in experimental myocardial infarction. Dimebon is less active than obsidan, finoptin (except for the size of the necrotic zone), and cordaron. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 122, No. 12, pp. 642–644, December, 1996     

Effects of sex steroid hormones on lipid peroxidation and glutathione antioxidant system in rat skin

Effects of estradiol and testosterone on the intensity of lipid peroxidation and contents of glutathione redox system components in the dermis and epidermis of rat skin were studied. Only estradiol induced considerable dose-dependent and tissue-specific biphasic antioxidant effects on the skin. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 128, No. 12, pp. 663–666, December, 1999     

Adhesion and growth of CaCo2 cells on surface-modified PEEK substrata

A series of surface-functionalized poly(ether ether ketone) (PEEK) films has been prepared by selective wet-chemistry; they are hydroxylated polymer (PEEK-OH) obtained by reduction, aminated polymer (PEEK-[]-NH2) prepared by coupling a diisocyanate reagent to PEEKOH (PEEK-[]-NCO) followed by hydrolysis, and carboxylated and aminocarboxylated polymers (PEEK-[]-GABA and PEEK-Lysine) resulting from the coupling of aminoacids to PEEK-[]-NCO. The aminated and carboxylated substrata promoted the adhesion and growth of CaCo2 cells in the presence of serum. Fibronectin (FN), an extra-cellular matrix protein, has been covalently fixed and/or adsorbed on various PEEK substrata, in the presence or not of a polymeric surfactant (Pluronic F68). The performances of the FN-grafted substrata (PEEK-[]-FN(1) and PEEK-[]-FN(2)) were significantly higher than those of reference substrata simply coated with FN (PEEK-OH(+FN)(1) and (2), PEEK-[]-NH2(+FN)(1) and (2)), considering the adhesion and spreading of CaCo2 cells in the absence of serum. Moreover, the stability of the adherent cells on the FN-adsorbed substrata dramatically depended on the experimental conditions applied during the PEEK coating with FN.     

THE ODYSSEY – A JUNGIAN PERSPECTIVE: INDIVIDUATION AND MEETING WITH THE ARCHETYPES OF THE COLLECTIVE UNCONSCIOUS

Homer's epic tale of the 20-year return of Odysseus from the Trojan War is investigated with particular reference to Jung's theory of individuation. Odysseus' meetings with 'the anima' in the form of goddesses, sirens and female monsters and his visit to Hades demonstrate the confrontation and humanization of aspects of the archetypal level of the psyche, central to Jung's theories of psychic growth and development. Jung's important ideas of the psychoid level and the transcendent function are explored and linked both to his investigations into medieval alchemy and with findings from contemporary neuroscience. The importance of Jung's constructive method of the interpretation of dreams and myths is shown to be central.