Distribution and Development of Peripheral Glial Cells in the Human Fetal Cochlea

The adult human cochlea contains various types of peripheral glial cells that envelop or myelinate the three different domains of the spiral ganglion neurons: the central processes in the cochlear nerve, the cell bodies in the spiral ganglia, and the peripheral processes in the osseous spiral lamina. Little is known about the distribution, lineage separation and maturation of these peripheral glial cells in the human fetal cochlea. In the current study, we observed peripheral glial cells expressing SOX10, SOX9 and S100B as early as 9 weeks of gestation (W9) in all three neuronal domains. We propose that these cells are the common precursor to both mature Schwann cells and satellite glial cells. Additionally, the peripheral glial cells located along the peripheral processes expressed NGFR, indicating a phenotype distinct from the peripheral glial cells located along the central processes. From W12, the spiral ganglion was gradually populated by satellite glial cells in a spatiotemporal gradient. In the cochlear nerve, radial sorting was accomplished by W22 and myelination started prior to myelination of the peripheral processes. The developmental dynamics of the peripheral glial cells in the human fetal cochlea is in support of a neural crest origin. Our study provides the first overview of the distribution and maturation of peripheral glial cells in the human fetal cochlea from W9 to W22.     

Cell number and cellular composition in vermiform larvae of dicyemid mesozoans

Cell numbers and cellular composition were examined in vermiform larvae of 44 species of dicyemid mesozoans phylum Dicyemida belonging to six genera: Conocyema , Dicyema , Dicyemennea , Dicyemodeca , Microcyema and Pseudicyema . In addition, the literature on vermiform larvae of another 59 species was reviewed. Vermiform larvae typically have a constant number of peripheral cells that are species specific. Interspecific variations in the total number of peripheral cells range from 10 to 39. The most frequent number is either 22 or 23. Differences in the total number of peripheral cells are mostly due to differences in the number of trunk peripheral cells, such as parapolar cells, diapolar cells and uropolar cells. The body length of vermiform larvae is positively correlated with the number of trunk peripheral cells. Interspecific variations in the total number of trunk peripheral cells range from 2 to 31. The most frequent number is 14. In species with 14 trunk peripheral cells, individual variations of cell numbers were minimal. In species with more trunk peripheral cells, some individual variations appeared. Increase and decrease of trunk cell number might cause diversity of dicyemids, which is possibly related to speciation in these simple multicellular animals.     

Identity, origin, and migration of peripheral glial cells in the Drosophila embryo

Glial cells are crucial for the proper development and function of the nervous system. In the Drosophila embryo, the glial cells of the peripheral nervous system are generated both by central neuroblasts and sensory organ precursors. Most peripheral glial cells need to migrate along axonal projections of motor and sensory neurons to reach their final positions in the periphery. Here we studied the spatial and temporal pattern, the identity, the migration, and the origin of all peripheral glial cells in the truncal segments of wildtype embryos. The establishment of individual identities among these cells is reflected by the expression of a combinatorial code of molecular markers. This allows the identification of individual cells in various genetic backgrounds. Furthermore, mutant analysis of two of these marker genes, spalt major and castor, reveal their implication in peripheral glial development. Using confocal 4D microscopy to monitor and follow peripheral glia migration in living embryos, we show that the positioning of most of these cells is predetermined with minor variations, and that the order in which cells migrate into the periphery is almost fixed. By studying their lineages, we uncovered the origin of each of the peripheral glial cells and linked them to identified central and peripheral neural stem cells.     

Imbalance of peripheral B lymphocytes and NK cells in rheumatoid arthritis

The study was focused on several cellular immune disorders correlated with the imbalance between peripheral blood B lymphocytes and NK cells in severe rheumatoid arthritis. By flow cytometry we calculated the proportions of T, T helper, T cytotoxic/suppressor, B lymphocytes and natural killer cells in peripheral blood. The mitogen-induced proliferation of peripheral lymphocytes was measured by tritium-labeld uridine incorporation. Experimental data highlight a connection between annomal values of the B to natural killer cells ratio and disorders of the peripheral mononuclear cells concentration. We also showed that the polyclonal proliferation capacity of peripheral lymphocytes in rheumatoid arthritis is solely related to the B to natural killer cells ratio or to the natural killer cells proportion. The study reveals a potential role of the imbalance between proportions of peripheral B lymphocytes and natural killer cells in the immune pathogenesis of rheumatoid arthritis, thus pointing out an interrelation between the adaptive and innate immune systems.     

Histochemical organization and cellular composition of ductal buds in developing human breast: evidence of cytochemical intermediates between epithelial and myoepithelial cells

In developing human breast, terminal end buds (TEBs), lateral buds (LBs), and lobules of three to five alveolar buds (ABs) predominate in prepubertal females, whereas lobules of ABs and lobules of up to 60 ductules predominate in pubertal females. The appearance of clefts in TEBs and LBs suggests that they are precursors of ABs. In histological sections the ductal buds are composed of a heterogeneous collection of cells that include cortical and peripheral cells. The cortical cells can line small lumina in TEBs/LBs, whereas the peripheral cells which cap their distal tips are more irregular and loosely packed. Monoclonal antibodies (MAb) to epithelial milk-fat globule membranes and antiserum to epithelial membrane antigen immunocytochemically stain the cortical cells, particularly where such cells line lumina, and weakly stain the peripheral cap cells. Similar histochemical staining patterns are observed in desialylated sections with peanut lectin. Antiserum and MAb to smooth muscle actin moderately stain the peripheral cap cells, and this staining increases the closer the peripheral cells become to the myoepithelial cells of the subtending duct. Similar but weaker staining patterns are observed with antibodies to vimentin. Keratin MAb PKK2 and LP34, which stain myoepithelial cells in preference to epithelial cells in main ducts, as well as MAb to epithelium-specific keratin 18, all stain many of the cortical/luminal cells in buds and lobules of developing breast; the peripheral cap cells are relatively unstained. It is suggested that the undifferentiated peripheral cap cells show transitional forms both to the cortical epithelial cells that eventually line the lumina and to the myoepithelial cells of the subtending duct.     

变应性鼻炎患者外周血中Tr1/Th3细胞的检测和分析

目的:检测变应性鼻炎(Allergic rhinitis,AR)患者和健康对照者外周血中IL-10+CD4+T细胞、TGF-β+CD4+T细胞(分别代表Tr1细胞和Th3细胞的特性)的比例,并探讨其在AR发病中的意义,为AR的治疗提供临床参考。方法:分离19例对粉尘螨过敏的AR患者和19例健康对照者外周血单个核细胞(PBMCs),采用流式细胞术分别检测外周血中IL-10+CD4+T细胞、TGF-β+CD4+T细胞的比例。结果:同健康对照者相比,AR患者外周血中IL-10+CD4+T细胞的比例显著降低[(1.66±0.48)%vs.(3.80.92)%,t=-9.08,P0.01)],AR患者外周血中TGF-β+CD4+T细胞的比例降低[(1.92±0.54)%vs.(4.76±1.12)%,t=-9.94,P0.01)]。结论:外周血中IL-10+CD4+T(Tr1)细胞比例的降低可能是AR发病的一个重要因素,提高AR患者外周血中分泌IL-10的Tr1细胞的比例可能在AR的治疗中具有重要意义。外周血中TGF-β1+CD4+T(Th3)细胞的比例显著降低,可能是AR发病的一个重要因素。但TGF-β1与AR关系的研究较少,特别是外周血中TGF-β1水平与AR的关系研究较少,需进一步研究。     

脂肪干细胞在周围神经损伤修复中的作用

周围神经损伤的修复是临床外科中的一个难题。尽管周围神经系统在损伤后具有内在的自我修复能力,但一般很难达到完全功能恢复,特别是近端的损伤或者大段的神经缺损。近年来,基于干细胞的细胞治疗为周围神经再生带来了曙光。大量研究表明干细胞可促进周围神经损伤的再生,然而其作用机制还不明确。为此,本文将对脂肪干细胞在周围神经损伤修复中作用包括向雪旺细胞分化、神经营养、血管形成、神经元保护、靶器官保护和免疫调节等作用进行归纳,并进一步探讨其潜在的作用机制。     

Transplantation of hematopoietic stem cells from the peripheral blood

Hematopoietic stem cells can be collected from the peripheral blood. These hematopoietic stem cells (HSC), or better progenitor cells, are mostly expressed as the percentage of cells than react with CD34 antibodies or that form colonies in semi-solid medium (CFU-GM). Under steady-state conditions the number of HSC is much lower in peripheral blood than in bone marrow. Mobilization with chemotherapy and/or growth factors may lead to a concentration of HSC in the peripheral blood that equals or exceeds the concentration in bone marrow. Transplantation of HSC from the peripheral blood results in faster hematologic recovery than HSC from bone marrow. This decreases the risk of infection and the need for blood-product support. For autologous stem-cell transplantation (SCT), the use of peripheral blood cells has completely replaced the use of bone marrow. For allogeneic SCT, on the other hand, the situation is more complex. Since peripheral blood contains more T-lymphocytes than bone marow, the use of HSC from the peripheral blood increases the risk of graft-versus-host disease after allogeneic SCT. For patients with goodrisk leukemia, bone marrow is still preferred, but for patients with high-risk disease, peripheral blood SCT has become the therapy of choice.     

Clonal biases of peripheral CD8 T cell repertoire directly reflect local inflammation in polymyositis

Polymyositis (PM) involves destruction of striated muscles by autoaggressive CD8 T cells, which accumulate and secrete cytotoxic effector molecules in the affected muscles. Previous studies of peripheral T cell repertoires from normal individuals and patients with viral infections have shown that primed CD8 T cells, unlike CD4 T cells, are prone to expand clonally and persist as large populations in the peripheral blood. These facts made us assume that autoaggressive myocytotoxic CD8 T cells would expand clonally in the peripheral blood from patients with PM. By clonal analyses of peripheral T cells from patients and age-matched controls, we show here that clonal expansion of CD8 T cells was more frequent in patients. This was not significant in CD4 T cells. In analogy to virus-specific T cells, the expanded T cells persisted as large populations over time. Analysis of the muscle biopsy specimens revealed that some of the expanded clones were infiltrating in the affected muscles from the same patients. These results provide the first evidence that local autoimmune reaction directly elicits significant biases in peripheral T cell repertoire. The expanded cells, which should be candidate autoaggressive T cells, were readily isolated from the peripheral blood for analysis of expressed genes including perforin. Thus, our findings should give us an immediate clue to analysis of the pathogenic T cells in PM.     

A Qualitative and Quantitative Study of a Sensory Epithelium in the Inner Ear of a Fish (Colisa labiosa; Anabantidae)

The macula lagenae of the anabantide fish Colisa labiosa was studied with light and transmission electron microscopy. (1) The sensory area is naturally divided in a central area (A) surrounded by a peripheral part (B). (2) Generally the central hair cells are separated by supporting cells, while the peripheral hair cells are found in groups. The cells of a group are not separated by supporting cells. (3) Tubuli-like structures, hexagonal in cross section, are found in all cells. In peripheral hair cells the longitudinally oriented tubuli-like structures are aggregated in thick bundles. (4) Variation in shape, electron density, stereocilia arrangement and size of mitochondria was found in different hair cells. (5) The central hair cells contain large accumulations of presynaptic bodies (10–44). Contrarily, the peripheral hair cells contain only a few pre-synaptic bodies (1–3). (6) The central hair cells are innervated by thick afferent (6–15 μm) and fine presumed efferent (less than 1 μm nerve fibres, while the peripheral hair cells are innervated by thin (1–6 μm) afferent nerve fibres only.     

The Characterisation of Pax3 Expressant Cells in Adult Peripheral Nerve

Pax3 has numerous integral functions in embryonic tissue morphogenesis and knowledge of its complex function in cells of adult tissue continues to unfold. Across a variety of adult tissue lineages, the role of Pax3 is principally linked to maintenance of the tissue’s resident stem/progenitor cell population. In adult peripheral nerves, Pax3 is reported to be expressed in nonmyelinating Schwann cells, however, little is known about the purpose of this expression. Based on the evidence of the role of Pax3 in other adult tissue stem and progenitor cells, it was hypothesised that the cells in adult peripheral nerve that express Pax3 may be peripheral glioblasts. Here, methods have been developed for identification and visualisation of Pax3 expressant cells in normal 60 day old mouse peripheral nerve that allowed morphological and phenotypic distinctions to be made between Pax3 expressing cells and other nonmyelinating Schwann cells. The distinctions described provide compelling support for a resident glioblast population in adult mouse peripheral nerve.     

Morphogenesis of an identified leech neuron: segmental specification of axonal outgrowth

We have investigated the development of segmental diversity in an identified leech neuron, the Retzius cell. Retzius cells in the genital segments differ from those in other segments in lacking central axons and contacting different peripheral targets: the genitalia. These differences are not apparent during initial axon outgrowth, when all Retzius cells follow the same morphogenetic pattern. Rather, they first appear about the time the peripheral axons of the genital segment Retzius cells contact the genital primordia. This suggests that the pattern of central and peripheral axonal outgrowth may be modified by an interaction with peripheral targets.     

Behavior of peripheral rods and their role in the life cycle of Myxococcus xanthus.

Myxococcus xanthus is a gram-negative bacterium with a complex life cycle including a developmental phase in which cells aggregate and sporulate in response to starvation. In previous papers, we have described a heretofore unsuspected layer of complexity in the development of M. xanthus: vegetatively growing cells differentiate into two cell types during development. In addition to the differentiation of spores within fruiting bodies, a second cell type, peripheral rods, arises outside fruiting bodies. The pattern of expression of proteins in peripheral rods is different from that of either vegetatively growing cells or spores, and peripheral rods express a number of recognized developmental markers. In this report, we examine four aspects of the biology of peripheral rods: (i) the influence of nutrients on the proportion of peripheral rods in a population of developing cells, (ii) the capacity of peripheral rods to recapitulate development, (iii) the development of peripheral rods on conditioned medium, and (iv) the ability of peripheral rods to resume growth on low amounts of exogenously added nutrients. The results of these studies suggest that peripheral rods play a significant role in the life cycle of M. xanthus by allowing the exploitation of low amounts or transient influxes of nutrients without the investment of energy in spore germination. The differentiation of vegetatively growing cells into two cell types that differ significantly in biology, shape, and localization within the population has been incorporated into a model of the life cycle of M. xanthus.     

Melanogenesis in cultures of peripheral nervous tissue: I. The origin and prospective fate of cells giving rise to melanocytes

Chick embryo spinal ganglia, peripheral nerves, and connective tissue usually associated with ganglia were cultured separately using several combinations of media and substrata. Melanocytes appear in cultures of both ganglia and peripheral nerves. The only cell type common to both the ganglion and peripheral nerve that could account for the observed pigment cells was the population of small cells with intensely staining nuclei that normally associates closely with nerve cell bodies and fibers. These cells could be distinguished morphologically from fibroblastic cells, which originated in the connective tissue capsule and did not undergo melanogenesis. We conclude that these small cells are supportive (Schwann, satellite, and perineurial) cell precursors and are one source of melanocytes in cultured peripheral nervous tissue.     

Degree of differentiation and blood vessel proximity in B16 melanoma

Corded structures consisting of rows of viable tumour cells around a central blood vessel are present in a number of transplantable mouse tumours, including transplantable B16 melanomas. These tumours were used to assess, by stereological means at the EM level, the range of differentiation of the melanoma cells, according to their position in relation to the central blood vessel. The mitotic index was also determined for perivascular and peripheral tumour cells separately. Furthermore, the transition of peripherally located cells into necrotic tumour cells is described at the EM level. Results shown an important increase in differentiation in peripheral tumour cells, whereas the mitotic index is highest in perivascular cells. Necrotic peripheral cells show features of apoptotic necrosis, together with necrosis of the ischaemic type. Results indicate that both proliferation and differentiation of melanoma cells are related to their position around a central blood vessel, and that peripheral necrosis is not exclusively due to lack of oxygen.     

Impulse cytophotometry studies of bone marrow and blood cells in children with acute lymphoblastic leukemia (ALL). 2. Lymphatic cells in blood

The DNA-content of mononuclear cells of the peripheral blood of infantile and juvenile ALL patients was investigated using Pulse Cytophotometry. The fraction of cells in S- and G2 + M-phase is significantly increased in comparison with samples of healthy probands. The fraction of DNA-synthesising cells (S-phase) of both peripheral blood (mononuclear cells) and bone marrow of leukemia patients cannot be significantly distinguished by mathematical methods. On the other hand, the fraction of cells in later phases of cell cycle (G2 + M-phase) is significant enhanced in the bone marrow in comparison with the peripheral blood. A high correlation was found between the number of leukocytes and fraction of G2 + M-phase cells in the peripheral blood of SR- and MR-patients. No correlation was found between the number of leukocytes and S-phase-fraction. The occurrence of aneuploid cell populations in the mononuclear fraction of peripheral blood in the acute state of ALL could be of importance for prognosis and regime of therapy.     

Selection of 3LL tumor subline resistant to natural effector cells concomitantly selected for increased metastatic potency

Summary The numbers of strongly adherent monocytes in the peripheral blood of normal subjects and cancer patients were determined. The method used was to place peripheral blood mononuclear cells in microwells and culture them for 1 week. At the end of that period, adherent macrophages were counted in the Coulter counter after release. Adherent cells per milliliter of blood, per total cells, and per mononuclear cells or monocytes plated were markedly diminished in the peripheral blood mononuclear cells of 44 melanoma, 23 breast cancer, 18 lung cancer, nine colon cancer, and 27 leukemia patients. Median values were 14.8×10⁴ adherent cells per ml peripheral blood for 86 normal subjects, as against 2.5×10⁴ per ml in the peripheral blood of the 125 patients (P<0.001). There was a poor correlation between the adherent cell numbers and the peripheral blood leukocyte counts, but an excellent correlation of the different adherent cell counts with each other. The number of adherent cells in the peripheral blood varied inversely with age in the cancer patients, but not in the normal subjects (r=0.29, P<0.005). When patients under age 50 were compared to the controls, the deficiency of adherent cells was slightly more severe in patients with stage IV lung cancer than in those with stage III lung cancer. In contrast, there was no difference in the degree of deficiency between patients with stage III melanoma and no evident disease and patients with stage IV disseminated metastatic disease. The implications of these results are discussed.     

CD4 positive Leu-8 negative helper-inducer T cells predominate in the human intestinal lamina propria

The regulatory function of peripheral blood CD4 T cells correlates with the presence or absence of the membrane glycoprotein recognized by anti-Leu-8 antibody; CD4,Leu8- T cells help Ig synthesis and CD4,Leu-8+ T cells suppress Ig synthesis. In contrast to CD4 T cells from the peripheral blood and organized gut-associated lymphoid tissues, intestinal lamina propria CD4 T cells were found to have diminished expression of the Leu-8 Ag. Therefore, studies were performed to determine whether the decreased expression of the Leu-8 Ag on lamina propria CD4 T cells correlates with a difference in the ability of peripheral blood and lamina propria CD4 T cells to regulate PWM-stimulated Ig synthesis. At high T cell to non-T cell ratios, the helper function of lamina propria CD4 T cells was significantly higher than that of peripheral blood CD4 T cells. When CD4 T cells were incubated with anti-Leu-8 antibody, the suppressor function of peripheral blood CD4 T cells was increased, but lamina propria CD4 T cells did not suppress Ig synthesis. No difference was found between the helper function of CD4,Leu-8- T cells and the suppressor function of CD4, Leu-8+ T cells isolated from either the peripheral blood or the lamina propria. Thus, the difference in the regulatory function of CD4 T cells from the peripheral blood and the lamina propria is due to the quantitative difference in CD4,Leu-8+ T cells in these sites. Consequently, the intestinal lamina propria is a site enriched in CD4,Leu-8- T cells which predominantly mediate help for Ig synthesis.     

Inhibition of Neuronal Nitric Oxide Synthase by Ethyl Pyruvate in Schwann Cells Protects Against Peripheral Nerve Degeneration

Neurochemical Research - Schwann cells are essential glial cells in the peripheral nervous system (PNS), and dysfunction of Schwann cells can induce various peripheral neurodegenerative diseases....     

Measurements of the dielectric properties of peripheral blood mononuclear cells and trophoblast cells using AC electrokinetic techniques

The separation of trophoblast cells from the maternal circulation could provide a valuable diagnostic tool for prenatal diagnosis of genetic abnormalities. This has been attempted using antibody methods, but due to non-specificity of the antibodies, maternal cell contamination remains a problem. We have investigated the potential of dielectrophoretic separation methods as a means of isolating trophoblast cells from mixed peripheral blood mononuclear cells. To determine the potential of this method the dielectric properties of trophoblast cells and mixed peripheral blood mononuclear cells were measured using dielectrophoretic crossover and single cell electrorotation methods. Both dielectrophoretic crossover data and electrorotation data gave an average specific membrane capacitance of the peripheral blood mononuclear cells of 11.5 mF m(-2). Trophoblast cells prepared using three different methods had a higher average specific membrane capacitance in the range 13-18 mF m(-2). The differences in capacitance between the cell types could be exploited as the basis of an AC electrokinetic-based system for the separation of trophoblast cells from peripheral blood mononuclear cells.