Prevalences of herpesviruses DNA sequences in salivary gland biopsies from primary and secondary Sj?gren's syndrome using degenerated consensus PCR primers.

BACKGROUND: Sj?gren's syndrome (SS) is an autoimmune exocrinopathy associated with multiple autoantibodies, lymphocyte infiltration of various organs, and functional deficiency of T cells. Several viruses have been implicated by PCR based studies, but their contribution to the pathophysiology of SS is still controversial. OBJECTIVES: In an attempt to explore the presence of human herpesviruses DNA sequences in salivary glands biopsies from patients suffering of SS, a recently developed strategy based on PCR with consensus degenerated primers that allowed to detect known and eventually unknown herpesviruses was used. STUDY DESIGN: Salivary glands biopsies from 55 patients suffering of primary and SS syndrome were explored by herpesviruses consensus PCR primers and all the PCR products were sequenced. RESULTS: Nine out of 55 salivary glands were positive by PCR and sequence analyses allowed to identify Epstein-Barr virus (EBV) in 6 cases and herpes simplex virus (HSV)-1 in 3 cases. We did not detect any sequences that could be related to a new herpesvirus. CONCLUSION: In view of the good sensitivity of the technique used, our study is not consistent with SS being associated with an unknown herpesvirus. However, our results suggest that EBV and HSV-1 could be implicated in a subset of SS cases and this possibility needs to be explored, to assess the potential benefit of antiviral drugs in some cases.     

Identification and characterization of a Streptococcus pyogenes operon involved in binding of hemoproteins and acquisition of iron

The hemolytic Streptococcus pyogenes can use a variety of heme compounds as an iron source. In this study, we investigate hemoprotein utilization by S. pyogenes. We demonstrate that surface proteins contribute to the binding of hemoproteins to S. pyogenes. We identify an ABC transporter from the iron complex family named sia for streptococcal iron acquisition, which consists of a lipoprotein (siaA), membrane permease (siaB), and ATPase (siaC). The sia transporter is part of a highly conserved, iron regulated, 10-gene operon. SiaA, which was localized to the cell membrane, could specifically bind hemoglobin. The operon's first gene encodes a novel bacterial protein that bound hemoglobin, myoglobin, heme-albumin, and hemoglobin-haptoglobin (but not apo-haptoglobin) and therefore was named Shr, for streptococcal hemoprotein receptor. PhoZ fusion and Western blot analysis showed that Shr has a leader peptide and is found in both membrane-bound and soluble forms. An M1 SF370 strain with a polar mutation in shr was more resistant to streptonigrin and hydrogen peroxide, suggesting decreased iron uptake. The addition of hemoglobin to the culture medium increased cell resistance to hydrogen peroxide in SF370 but not in the mutant, implying the sia operon may be involved in hemoglobin-dependent resistance to oxidative stress. The shr mutant demonstrated reduced hemoglobin binding, though cell growth in iron-depleted medium supplemented with hemoglobin, whole blood, or ferric citrate was not affected, suggesting additional systems are involved in hemoglobin utilization. SiaA and Shr are the first hemoprotein receptors identified in S. pyogenes; their possible role in iron capture is discussed.     

Persistent expression of the alpha1S-dihydropyridine receptor in aged human skeletal muscle: implications for the excitation-contraction uncoupling hypothesis of sarcopenia

Previous studies on aged animal muscle suggest that excitation-contraction uncoupling and fibre transitions play a central role in sarcopenia, the progressive loss and functional decline of aging skeletal muscle fibres. A drastic reduction in the voltage-sensing alpha1S-subunit of the transverse-tubular dihydropyridine receptor is believed to be the underlying cause for a decreased transmission of the surface depolarization signal into Ca2+-mediated muscle contraction. Extending these studies to human muscle, we asked whether potential changes in the relative expression of the voltage sensor occur in senescent human fibres. For internal standardization and as markers of potential fast-to-slow transitions, the fast isoforms of the Ca2+-binding element calsequestrin and the myosin heavy chain were employed. Besides small inter-individual variations in expression levels, the microsomal immunoblot analysis of vastus lateralis autopsy specimens from male humans aged 18 to 82 years of age showed no major changes in the relative abundance of the alpha1S- and alpha2-dihydropyridine receptor, fast calsequestrin and the slow/fast myosin heavy chains. The oligomeric status of the alpha1S-dihydropyridine receptor was unaltered in aged fibres. Biochemical assays revealed no significant modifications in Ca2+-ATPase activity and a reduced Ca2+-binding capacity in aged human muscle preparations. Although impairments of other Ca2+-regulatory proteins and/or disturbed protein-protein interactions might be involved in the pathophysiological changes of sarcopenia, dihydropyridine receptor and calsequestrin expression seem to be preserved during the aging process of human skeletal muscle fibres. Hence, the supposition that excitation-contraction uncoupling is responsible for sarcopenia can not be transferred from animal models to senescent human muscle without modifications.     

试剂对脱钙骨基质成骨能力影响的实验研究

目的 :研究异体骨基质制备过程中常用的脱脂和脱钙试剂溶液对其成骨能力的影响。方法 :8周鼠龄的Wistar雌鼠作为供体 ,切取胫股骨 ,碾磨成 12 5～ 80 0微米的颗粒 ,分成四组 ,分别用丙酮 -盐酸、丙酮 -乙二胺四乙酸 (EDTA)、三氯甲烷 -甲醇 -EDTA或三氯甲烷 -甲醇 -盐酸 (控制组 )脱脂和脱钙。冷冻干燥处理后 ,每 3 0mg装入一胶囊中。 60只 6周鼠龄的Wistar雌鼠作为受体 ,植入腰背肌中 ,每只鼠接受同一组植入材料 2枚。术后 6周取标本测定重量、干燥后的重量、钙含量、碱性磷酸酶含量和组织形态学定量测定。结果 :丙酮 -盐酸组的干燥重量 (P <0 .0 1)和钙含量 (P <0 .0 5 )明显高于控制组。结论 :用丙酮清除脂质的异体骨基质成骨能力优于用三氯甲烷 -甲醇混合液。EDTA或盐酸脱钙对其成骨能力无明显影响。     

Lymph node pathology in pulmonary veno-occlusive disease and pulmonary capillary heamangiomatosis

To assess the histological bases of lymphadenomegaly, which has been reported as a frequent radiological finding in pulmonary veno-occlusive disease (PVOD), we have reviewed pulmonary and mediastinal lymph nodes resected during lung transplantations in 19 patients suffering from PVOD and related pulmonary capillary haemangiomatosis (PCH). Lymphatic congestion was common and was often obvious in subsegmental and segmental lymph nodes. Vascular transformation of the sinuses, intra-sinusal haemorrhage with erythrophagocytosis and lymphoid follicular hyperplasia were frequent especially in lobar, hilar and mediastinal lymph nodes. These lesions were very significantly less frequent in 33 cases of pulmonary hypertension unrelated to PVOD. Due to their thoracic location, these non-specific lesions could simulate other diagnoses such as Castleman disease or lymphangioleiomyomatosis. However, in the setting of pulmonary hypertension, they should suggest PVOD and PCH. They are probably secondary to venous congestion, veno-lymphatic shunts and angiogenetic factors associated with these diseases.     

Human neutrophil elastase inhibition with a novel cotton-alginate wound dressing formulation

Occlusion and elasticity were combined in a novel cotton-based alginate dressing containing a nontoxic elastase inhibitor. Cotton gauzes were modified with a textile finishing process for incorporating alginate to yield a dressing material that retains elasticity while enhancing absorption. The algino-cellulose conjugates were formed through citric acid crosslinking of cellulose and alginate. The alginate-citrate finishes were applied to cotton gauzes in various formulations containing citric acid, sodium hypophosphite, and polyethylene glycol. The modified gauzes contain a citrate conjugate of alginate and cellulose that gels upon hydration. The alginate-citrate finishes were combined with the neutrophil elastase inhibitor, oleic acid, to demonstrate the ability of the algino-cellulose fibers to release the inhibitor and neutralize destructively high levels of neutrophil elastase found in nonhealing and burn wounds. Four types of gauzes were examined for the effect of the algino-cellulose finish on cotton gauze absorbency and elasticity. Fourier transform infrared (FTIR) spectroscopy of the film and alginate-citrate finished cotton showed formation of the alginate and citrate cellulose esters. Scanning electron microscopy analysis revealed large areas of the yarn surface covered by the alginate film with a smooth surface on the original fibers. Wetting of the gauze surface resulted in formation of a hydrated gel on the yarns with apparent swelling of the film and the fiber-coated alginate.     

Difference in the perception of the horizon during true and simulated tilt in the absence of semicircular canal cues

Perception of tilt (somatogravic illusion) in response to sustained linear acceleration is generally attributed to the otolithic system which reflects either a translation of the head or a reorientation of the head with respect to gravity (tilt/translation ambiguity). The main aim of this study was to compare the tilt perception during prolonged static tilt and translation between 8 and 20° of tilt relative to the gravitoinertial forces (i.e., G and GIF, respectively) when the semicircular cues were no more available. An indirect measure of tilt perception was estimated by means of a visual and kinesthetic judgment of the gravitational horizon. The main results contrast with the interpretation regarding the tilt/translation ambiguity as the same orientation relative to the shear forces G for the true tilt or GIF in the centrifuge did not induce the same horizon perception. Visual adjustment and arm pointing in the centrifuge were always above the ones observed in a G environment. Part of the lowering of the judgment in the centrifuge may be related to the mechanical effect of GIF on the effectors as shown by the shift of the egocentric coordinates in the direction of GIF. The role of the extravestibular graviceptors in the judgment of the degree of tilt of one’s own body relative to G or GIF was discussed.