Twisted plywood architecture of collagen fibrils in human compact bone osteons

Summary Ultrathin sections of decalcified human compact bone, observed by transmission electron microscopy, reveal that collagen fibrils can be distributed in the form of a superimposed series of nested arcs. This characteristic pattern has never been interpreted in previous works on compact bone structure. We demonstrate, by goniometric observations at the ultrastructural level, that such series of nested arcs are a consequence of the “twisted plywood” architecture of collagen fibrils in the compact bone matrix. In the same specimens, an “orthogonal plywood” disposition of collagen fibrils is also observed; a transition exists between these two types of orders. We show that the “twisted plywood structure” accounts well for certain optical properties of osteons, observed in polarizing microscopy, described as “intermediate osteons.” The particular geometry of collagen fibrils, leading to nested arcs in oblique sections, is analogous to the distribution of molecules in certain liquid crystals (called cholesteric liquid crystals). The principle of a liquid crystalline self-assembly of the collagen matrix in bone is therefore discussed.     

Eye movement quantitative evaluation before and after high-dose 6-methylprednisolone in multiple sclerosis

We studied saccadic and smooth pursuit eye movements in 24 patients suffering from multiple sclerosis during disease worsening, before and after high-dose 6-methylprednisolone infusions. Quantitative evaluation of saccades was based on amplitude/duration and amplitude/peak velocity relationships, precision (i.e. the ratio of actual to desired saccade amplitude) and the latency, whereas smooth pursuit eye movements were studied using target velocity/performance index relationship. At basal recordings, 22/24 (91.7%) of the patients showed at lest one abnormality. Eleven of the 24 patients (45.8%) showed modification of one or several parameters: improvement in 6 patients, worsening in 2, coexistence of both trends in 3. Latency improvement was the only significant modification when patients were considered as a group. Neurophysiological modifications did not correspond to clinical changes.     

Structural and ultrastructural characteristics of human pineal gland,and pineal parenchymal tumors

We have studied 20 pineal parenchymal tumors (PPT) and 4 normal or cystic pineal glands both by light and electron microscopy and immunohistochemistry with antibodies against glial markers [glial fibrillary acidic protein (GFAP) and protein S-100] or neural/neuroendocrine markers [neurofilaments (NF), synaptophysin and chromogranin A]. Light microscopy revealed the cellular organization of pinealocytes in the normal gland and in different morphological types of pineal tumors (typical pineocytomas, PPT with intermediate differentiation, mixed PPT exhibiting elements of both pineocytoma and pineoblastoma and pineoblastomas). Immunohistochemistry showed the presence of GFAP and protein S-100 in interstitial cells in nonneoplastic pineal gland. Cell processes were labeled with anti-synaptophysin and anti-NF antibodies. No immunoreactivity was found for chromogranin A in non-neoplastic pineal gland. In pineocytomas, GFAP and protein S-100 were observed in interstitial cells. Synaptophysin and NF were present in the large rosettes of pineocytomas. Synaptophysin, NF and chromogranin A were present in pineocytomas with a lobular arrangement of cells. Anti-chromogranin A immuno-reactivity was also seen in lobular areas of some PPT with intermediate differentiation. Analysis of normal human pineal gland by electron microscopy showed the presence of vesicle-crowned rodlets (VCR or synaptic ribbons), fibrous filaments (F), paired twisted filaments but few dense-core vesicles (DCV) in normal pinealocytes. Tumoral pineal cells appeared to differentiate either towards a neurosensory pathway characterized by the presence of sensory cells elements (VCR and F), or towards a neuroendocrine pathway, with the occurrence of many DCV. Immunogold labeling demonstrated the presence of chromogranin A in neurosecretory granules.Supported by grants from the Région Rhône Alpes and from INSERM (CJF 90-10)     

Autoimmune reactions in patients with M-component and peripheral neuropathy.

A study of 17 patients with autoimmune axonal or demyelinating peripheral neuropathy in combination with M-component is described. The M-component was associated with MGUS (monoclonal gammopathy of undetermined significance) in 12 patients, CLL in one patient, WaldenstrÖm's disease in one patient, and myeloma in three patients. Immunohistological examination with direct and indirect fluorescence showed binding of antibodies to nerve structures of the same class and light chain as seen in the M-component. In five cases of IgM M-component, the demyelinating neuropathy was caused by binding of the IgM M-protein and complement C3b to myelin-associated glycoproteins (MAG). In 12 cases with axonal neuropathy, binding of IgG to the connective tissue of the peri- and endoneurium was found in 50% of cases, IgM in five cases, and IgD in one case. None of the patients had central nervous system (CNS) symptoms. The clinical and therapeutic difficulties are discussed; only two patients with an acute course responded to immunosuppression. A marked co-expression of other autoimmune phenomena is interpreted in the light of cross-reactions between the autoantibody and similar tissue autoantigens.     

Depression and immune function

Clinical studies have demonstrated that measures of cell-mediated immune function are altered in bereaved persons and depressed patients. This review article focuses on our recent observations of changes in T cell subpopulations and natural killer cytotoxicity in women undergoing adverse life events including conjugal bereavement. A reduction in natural cytotoxicity has also been found in depressed patients. The mechanism by which psychologic states might influence immune function is discussed.     

雷公藤服用者精液中乳酸脱氢酶及其同功酶C_4活性的研究

本文对19例中药雷公藤服用者精子、精浆中乳酸脱氢酶(LDH)及同功酶C_4(LDHC_4)的活性进行了测定分析。发现服药后以单位数量精子表示的LDHC_4活性在精子、精浆中均有明显升高(双侧非参数秩和检验,分别为P<0.01和P<0.02);通过酶活性与精子计数的相关分析,显示服药后精浆LDHC_4活性(mU/ml)与精子计数的正相关性(r=0.2279)较服药前(r=0.5505)弱,可能与精液中精子以外的其他LDHC_4来源贡献增大有关,诸如生精细胞的分解增多等。本文认为服药后精子LDHC_4活性上升,精液中非成熟精子比例增高是其原因之一。     

大鼠卵巢、睾丸人绒毛膜促性腺激素受体的比较研究

以分离的细胞膜为受体制剂，对大鼠卵巢及睾丸人绒毛膜促性腺激素（ＨＣＧ）受体进行比较研究，发现二者的受体结合特性有一定差异；同时将大鼠寒丸膜及睾丸匀浆作对比，友现睾丸膜制剂较睾丸匀浆更能准确地体现睾丸ＨＣＧ受体的真正特性。     

Human tonsil,blood and bone marrow in vivo-induced B cells capable of spontaneous and high-rate immunoglobulin secretion in vitro: Differences in the requirements for factors and for adherent and bone marrow stromal cells,as well as distinctive adhesion molecule expression

Human B cells capable of spontaneous IgG secretion are commonly found in circulation and in lymphoid tissues such as tonsil and bone marrow (BM). The present study compares the mechanisms that regulate tonsil, blood and BM B cells capable of spontaneous IgG secretion. The BM cell subset produced IgG during a markedly longer period of time (14 days) than did tonsil and blood cell subsets (2–3 days). Blood and BM, but not tonsil, B cell IgG secretion depended on the presence of adherent cells, as demonstrated by adherent cell depletion and re-addition experiments. Stromal BM cells supported linear IgG secretion by non-adherent BM cells for 2 weeks, but were unable to prolong the short-term IgG secretion by tonsil and blood cells. Different factors induced IgG secretion in each of the three B cell populations as optimal IgG secretion by tonsil, blood or BM cell subsets required either tumor necrosis factor-α, interleukin-6 or fibronectin + interleukin-6, respectively. Finally, these populations also showed differences in the expression of adhesion molecules; the tonsilar cell subset was PNA^+/? CD44⁺ CD49d⁺ CD49e^? Leu-8^+/?, the blood cell subset was PNA^? CD44^+/? CD49d⁺ CD49e^? Leu-8⁺ and the BM cell subset was PNA^? CD44^+/? CD49d⁺ CD49e^? Leu-8^?. These results suggest that the mechanisms controlling the final differentiation and the expression of adhesion molecules in these B lymphocytes exhibit territorial specificity.     

Human spumaretrovirus antibody reactivity in multiple sclerosis

The role of human spumaretrovirus (HSRV) infections in the pathogenesis of multiple sclerosis (MS) was investigated with recombinant HSRV env-specific enzyme-linked immunosorbent assay. The presence of HSRV antibodies was determined in pairs of serum and cerebrospinal fluid (CSF) samples from 60 MS patients. In 7 of these patients serial serum and CSF samples were obtained in relation to the clinical activity of the disease during a period of 2 years. No increased antibody reactivity was demonstrable in the MS population compared with 14 aseptic meningitis patients, 50 blood donors and 16 healthy controls. Slightly elevated levels of antibodies were demonstrable in serum and/or CSF in 4 MS patients but also in 1 patient with aseptic meningitis, 1 blood donor and 1 child. No marked serum or CSF HSRV antibody fluctuation was observed in the MS patients followed longitudinally. Thus, this study does not support the involvement of HSRV in the pathogenesis of MS.     

胶体金免疫层析法检测尿hCG的质量控制方法探讨

目的通过对胶体金免疫层析法（GICA）试纸条评价,建立该方法的检测尿hCG的室内质控.方法利用hCG不同浓度的标准品评价试纸条的敏感性、重复性、稳定性、检测范围,检测温度及时间对试纸条检测尿hCG结果的影响等.结果GICA的检测范围25-100万mlU/ml,最低检出限达25mIU/ml,大于200万mIU/ml时存在后带现象.试纸条反应5分钟后呈色均一,最佳检测温度为4-30℃.结论灵敏度检测可作为GICA室内质控的主要指标,它能保证检测结果的准确性.