bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regulation of complement C3 and C4 synthesis in human peritoneal mesothelial cells by peritoneal dialysis fluid
Authors: TANG S , LEUNG J C K , CHAN L Y Y , TSANG A W L , CHEN C X R , ZHOU W , LAI K N , SACKS S H 
Published: March 2004

SUMMARY
Although complement is activated in the peritoneal cavity during chronic peritoneal dialysis (PD), little is known about its role in peritoneal defence and injury related to long-term PD. We examined the impact of glucose and commercial peritoneal dialysis solutions on complement expression in HPMCs obtained by primary culture from omental tissues of consented patients undergoing elective abdominal surgery. Constitutive expression of C3 and C4 mRNA in HPMCs was up-regulated upon exposure to 75 mm glucose in a time-dependent manner. C3 and C4 protein was secreted in both apical and basolateral directions. Glucose doses beyond 100 mm markedly down-regulated C3 and C4 expression, and stimulated LDH release dose-dependently. Such cytotoxic effects were attenuated using equivalent doses of mannitol instead of glucose. Treatment with conventional lactate-buffered dialysis solution gave rise to down-regulation of C3 and C4 expression, and heightened LDH release in HPMCs. These effects correlated with the glucose strength of the solution, persisted despite replacement with a bicarbonate-buffered solution, aggravated by glycated albumin, and were partially abrogated by supplementation with 10% fetal bovine serum in the culture system. Our findings suggest that the artificial conditions imposed by PD lead to alterations in local complement synthesis that have implications for the role of the peritoneal mesothelium in both inflammation and defence.
Early deficit of lymphocytes in Wiskott–Aldrich syndrome: possible role of WASP in human lymphocyte maturation
Authors: PARK J Y , KOB M , PRODEUS A P , ROSEN F S , SHCHERBINA A , REMOLD-O'DONNELL E 
Published: March 2004

SUMMARYWiskott–Aldrich syndrome (WAS) is an X-linked platelet/immunodeficiency disease. The affected gene encodes WASP, a multidomain protein that regulates cytoskeletal assembly in blood cells. Patients have recurring infections, and their lymphocytes exhibit deficient proliferative responses in vitro. We report an evaluation of peripheral blood lymphocytes of 27 WAS patients, aged one month to 55 years. Whereas NK cells were normal, a significant deficit of T and B lymphocytes was observed. The number of lymphocytes was already decreased in infant patients, suggesting deficient output. Both CD4 and CD8 T lymphocytes were affected; the decrease was most pronounced for naïve T cells. Naïve CD4 lymphocytes of patients showed normal expression of Bcl-2, and Ki-67, and normal survival in vitro, suggesting that their in vivo survival and proliferation are normal. The collective data suggest that the patients’ lymphocyte deficit results from deficient output, likely due to abnormal lymphocyte maturation in the thymus and bone marrow. We propose that WASP plays an important role not only in the function of mature T lymphocytes, but also in the maturation of human T and B lymphocytes and that impaired lymphocyte maturation is central to the aetiology of WAS immunodeficiency.
Reduced ratio of protectiveversusproinflammatory cytokine responses to commensal bacteria in HLA-B27 transgenic rats
Authors: DIELEMAN L A , HOENTJEN F , QIAN B-F , SPRENGERS D , TJWA E , TORRES M F , TORRICE C D , SARTOR R B , TONKONOGY S L 
Published: March 2004

SUMMARYGerm-free HLA-B27 transgenic (TG) rats do not develop colitis, but colonization with specific pathogen-free (SPF) bacteria induces colitis accompanied by immune activation. To study host-dependent immune responses to commensal caecal bacteria we investigated cytokine profiles in mesenteric lymph node (MLN) cells from HLA-B27 TG versus nontransgenic (non-TG) littermates after in vitro stimulation with caecal bacterial lysates (CBL). Supernatants from CBL-stimulated unseparated T- or B- cell-depleted MLN cells from HLA-B27 TG and non-TG littermates were analysed for IFN-γ, IL-12, TNF, IL-10 and TGF-β production. Our results show that unfractionated TG MLN cells stimulated with CBL produced more IFN-γ, IL-12 and TNF than did non-TG MLN cells. In contrast, CBL-stimulated non-TG MLN cells produced more IL-10 and TGF-β. T cell depletion abolished IFN-γ and decreased IL-12 production, but did not affect IL-10 and TGF-β production. Conversely, neither IL-10 nor TGF-β was produced in cultures of B cell-depleted MLN. In addition, CD4+ T cells enriched from MLN of HLA-B27 TG but not from non-TG rats produced IFN-γ when cocultured with CBL-pulsed antigen presenting cells from non-TG rats. Interestingly, IL-10 and TGF-β, but not IFN-γ, IL-12 and TNF were produced by MLN cells from germ-free TG rats. These results indicate that the colitis that develops in SPF HLA-B27 TG rats is accompanied by activation of IFN-γ-producing CD4+ T cells that respond to commensal bacteria. However, B cell cytokine production in response to components of commensal intestinal microorganisms occurs in the absence of intestinal inflammation.
The membrane attack complex, C5b-9, up regulates collagen gene expression in renal tubular epithelial cells
Authors: ABE K , LI K , SACKS S H , SHEERIN N S 
Published: March 2004

SUMMARY
Evidence suggesting a direct role for proteinuria in the pathogenesis of renal tubulointerstitial fibrosis is accumulating. However the mechanism by which proteinuria leads to injury is unknown. In proteinuric states complement proteins are filtered through the glomerulus and could contribute to the tubular damage. The aim of this study was to investigate the role of complement activation in the progression of interstitial fibrosis. To determine whether complement activation may be responsible for the pro-fibrotic response that occurs in the tubulointerstitial compartment we stimulated primary cultures of proximal tubular epithelial cells with membrane attack complex, C5b-9. This led to increased mRNA concentrations of both collagen type IV and its intracellular chaperone, Heat Shock Protein 47 (HSP47). To determine whether this occurred in vivo Adriamycin was used to induce proteinuria in female Balb/c mice. The expression of collagen type IV and HSP47 was increased in proteinuric mice compared to control mice. In proteinuric mouse kidney, C3 was deposited at sites of tubulointerstitial injury and there was a relationship between C3 deposition and immunochemical staining for collagen type IV and HSP47. In situ hybridization suggested that the renal tubular epithelium was actively expressing HSP47 mRNA and, by implication, excess collagen. These observations support the hypothesis that complement activation on tubular epithelial cells can directly increase the pro-fibrotic process associated with tubulointerstitial damage.
Differential effect of calcium phosphate and calcium pyrophosphate on binding of matrix metalloproteinases to fibrin: comparison to a fibrin-binding protease from inflammatory joint fluids
Authors: MAKOWSKI G S , RAMSBY M L 
Published: March 2004

SUMMARY
The ability of calcium phosphate (CaP) and calcium pyrophosphate (CaPPi) to mediate matrix metalloproteinase-2 and -9 (MMP-2 and MMP-9) binding to fibrin was evaluated. Substrate gel electrophoresis (gelatin zymography) revealed that CaP bound MMP-2 and MMP-9, forming a high molecular weight aggregate with lowered electrophoretic mobility. Formation of the CaP : MMP aggregate was necessary for fibrin binding. In contrast, CaPPi did not aggregate MMPs and did not promote uptake of MMPs into fibrin. Scatchard analysis (Ca/P ratio) revealed that CaPPi (1·96) was chemically similar to calcium pyrophosphate dihydrate (2·00) compared to amorphous CaP (1·50) or crystalline CaP, hydroxyapatite (1·66). MMP : CaP interaction appeared to be electrostatic in nature as high salt concentration (NaCl &gt; 150 mm) reduced binding. In contrast, two non-ionic detergents (Brij-35 and Tween-20) did not prevent MMP : CaP binding. MMP : CaP interaction did not involve the C-terminal MMP region because the specific tissue inhibitor of metalloproteinases (TIMPs) also did not block MMP : CaP interaction and fibrin binding. Although MMP : CaP binding could be decreased with albumin, this effect appeared non-specific due to the high albumin concentration required. High albumin concentration could also partially dissociate preformed MMP : CaP complexes. Interestingly, type I and type IV collagen substantially increased MMP : fibrin-binding activity, whereas denatured collagen, gelatin, did not. Inflammatory joint fluid from five patients also demonstrated similar MMP fibrin-binding activity consistent with CaP mediation. The relevance of these findings to CaP and CaPPi in the pathogenesis of crystal arthropathies such as basic calcium phosphate (BCP) and calcium pyrophosphate dihydrate crystal disease (CPPD) is discussed.
Antibodies to TSH-receptor in thyroid autoimmune disease interact with monoclonal antibodies whose epitopes are broadly distributed on the receptor
Authors: MINICH W B , LENZNER C , MORGENTHALER N G 
Published: March 2004

SUMMARYThe hyperthyroidism of Graves’ disease (GD) is caused by TSH-receptor (TSH-R) stimulating autoantibodies (TSAb), leading to overproduction of thyroid hormones. We present evidence for TSAb interaction with three distinct regions of the TSH-R, one in immediate vicinity of the carboxy terminal serpentine. Three murine monoclonal antibodies (MoAbs 28·1, A9 and 31·7) directed to amino acids 36–40, 147–228 and 382–415 were labelled and tested for their binding to human recombinant TSH-R on solid phase. All MoAbs bound to TSH-R with a Kd of 8–12 nm and showed no competition among themselves. We tested 114 sera from euthyroid controls, 118 TBII positive sera from patients with GD (containing TSAb confirmed by bioassays), 16 TBII positive sera from patients with autoimmune thyroid disease (AIT), who were hypothyroid and had TSH blocking antibodies (TBAb), and 20 patients with AIT, who were hypothyroid but negative for all TRAb. Mid-regional MoAb A9 tracer achieved the highest sensitivity in the GD group (72·0%), whereas C-terminal MoAb 31·7 found most sera positive in the AIT group (87·5%). Surprisingly, the N-terminal MoAb 28·1 had the lowest sensitivity in the GD (10·4%) and AIT group (43·8%). Using a mixture of all three tracer MoAbs did not increase the sensitivity in the GD or AIT group, compared to the best single MoAb alone. Median inhibition of MoAb A9 was significantly (P &lt; 0·001) higher than inhibition of MoAbs 28·1 or 31·7 in the group of GD patients but not in other groups. Almost all patient sera with positive reactivity in the MoAb tracer assays had TBII values in the higher range. However, there were many highly TBII positive sera, which did not show a displacement of the MoAb tracers. We conclude that, contrary to some reports, the binding of TSAb and TBAb to the TSH-R is not restricted to distinct and distant epitopes. The middle part of the TSH-R seems to be more relevant for TSAb binding than the N-terminal part, while a proportion of TSAb autoantibodies also binds to a C-terminal epitope of the TSH-R. The method described here is a TSH independent competitive assay for the detection of TSH-R autoantibodies.
Induction of experimental autoimmune encephalomyelitis in Dark Agouti rats without adjuvant
Authors: STOSIC-GRUJICIC S , RAMIC Z , BUMBASIREVIC V , HARHAJI L , MOSTARICA-STOJKOVIC M 
Published: March 2004

SUMMARYExperimental autoimmune encephalomyelitis (EAE) is a well-recognized model for multiple sclerosis (MS) in humans. However, adjuvants used with encephalitogens to induce EAE produce non-specific effects interfering with the mechanisms involved in the autoimmune response to the central nervous system (CNS) tissue. It is therefore important to establish a more suitable model of EAE for analysis of autoimmune phenomena resembling those operative in MS. Here we report that EAE can be induced regularly in Dark Agouti (DA) strain of rats with spinal cord tissue without any adjuvant, as judged by both clinical and histological parameters. The incidence and severity of EAE depended on the origin of the encephalitogen, the rat versus guinea pig spinal cord homogenate being more efficient. Furthermore, EAE could be reinduced in animals which had recovered from disease that had been induced actively with encephalitogen alone, suggesting the role of adjuvant-generated non-specific mechanisms in resistance to reinduction of EAE. Thus, EAE induced in DA rats with encephalitogen alone provides a reproducible model for defining pathogenically relevant events in CNS autoimmunity devoid of the potentially misleading effects of adjuvants.
P-selectin glycoprotein ligand 1 therapy ameliorates established collagen-induced arthritis in DBA/1 mice partly through the suppression of tumour necrosis factor
Authors: SUMARIWALLA P F , MALFAIT A M , FELDMANN M 
Published: March 2004

SUMMARYWe investigated the therapeutic potential of P-selectin glycoprotein ligand (PSGL)-1 in established collagen-induced arthritis (CIA) in DBA/1 mice. PSGL-1 is the high-affinity specific ligand for P-selectin and is thus important in cell recruitment to inflammatory sites. I-316 PSGL-1 or rPSGL-1Ig fusion protein were administered to mice after the onset of clinical arthritis for 10 days, and the effect of treatment on both clinical and histopathological progression of disease was studied. It was found that both PSGL-1 biologicals effectively suppressed progression of clinical arthritis, and this was accompanied by protection against damage of joint tissues. We sought to investigate a mechanism underlying the effect of rPSGL-1Ig on the reduction of clinical arthritis. Blockade of PSGL-1/P–selectin interaction blocks recruitment of leucocytes, thus we observed a notable reduction in viable cell numbers of synoviocytes from rPSGL-1Ig treated mice. In view of this finding we suspected an effect of treatment on the production of pro-inflammatory mediators such as bioactive tumour necrosis factor-α (TNF) in synovial membrane ex vivo cell cultures. Production of TNF was reduced in arthritic mice that had been treated with rPSGL-1Ig. To further investigate the mechanism of rPSGL-1Ig, we explored the possibility that PSGL-1 might also have a direct signalling effect on TNF release from inflammatory cells. Thus synoviocyte cultures from arthritic mice were incubated with rPSGL-1Ig. A significant reduction in the spontaneous bioactive TNF release from these cultures was noted. We therefore confirmed these surprising findings using cultures of a mouse macrophage like cell line RAW 264·7, stimulated by LPS. Our results indicate that both forms of PSGL-1 have significant therapeutic effects in CIA murine model of RA. The mechanism of action involves reduced cellularity of synovium as anticipated, along with a reduction in TNF production from inflammatory cells in the synovium. The latter mechanism needs further mechanistic analysis.
Evaluation of conformational epitopes on thyroid peroxidase by antipeptide antibody binding and mutagenesis
Authors: GORA M , GARDAS A , WIKTOROWICZ W , HOBBY P , WATSON P F , WEETMAN A P , SUTTON B J , BANGA J P 
Published: March 2004

SUMMARYAutoantibodies to thyroid peroxidase (TPO) recognize predominantly conformational epitopes, which are restricted to two distinct determinants, termed immunodominant domain region (IDR) A and B. These dominant determinants reside in the region with structural homology to myeloperoxidase (MPO)-like domain and may extend into the adjacent complement control protein (CCP) domain. We have explored the location of these determinants on the MPO-like domain of the structural model of TPO, by identifying exposed hydrophilic loops that are potential candidates for the autoantigenic sites, generating rabbit antipeptide antisera, and competing with well characterized murine monoclonal antibodies (mabs) specific for these two IDRs. We recently defined the location of IDR-B, and here report our findings on the location of IDR-A and its relationship to IDR-B, defined with a new panel of 15 antipeptide antisera. Moreover, in combination with single amino acid replacements by in vitro mutagenesis, we have defined the limits of the IDR-B region on the TPO model. The combination of antisera to peptides P12 (aa 549–563), P14 (aa 599–617) and P18 (aa 210–225) inhibited the binding of the mab specific for IDR-A (mab 2) by 75%. The same combination inhibited the binding of autoantibodies to native TPO from 67 to 94% (mean 81·5%) at autoantibody levels of 5 IU. Fabs prepared from the antipeptide IgG and pooled in this combination were also effective in competition assays, thus defining the epitopes more precisely. IDR-A was found to lie immediately adjacent to IDR-B and thus the two immunodominant epitopes form an extended patch on the surface of TPO. Finally, by single amino acid mutagenesis, we show that IDR-B extends to residue N642, thus further localizing the boundary of this autoantigenic region on the structural model.
Recombination activating genes (RAG) induce secondary Ig gene rearrangement in and subsequent apoptosis of human peripheral blood circulating B lymphocytes
Authors: NAGAFUCHI H , YOSHIKAWA H , TAKEBA Y , NARA K , MIURA K , KUROKAWA M S , SUZUKI N 
Published: March 2004

SUMMARYRecombination activating gene (RAG) re-expression and secondary Ig gene rearrangement in mature B lymphocytes have been reported. Here, we have studied RAG expression of peripheral blood B lymphocytes in humans. Normal B cells did not express RAG1 and RAG2 spontaneously. More than a half of circulating B cells expressed RAG proteins, when activated with Staphylococcus aureus Cowan I (SAC) + IL-2. DNA binding activity of the RAG complex has been verified by a gel shift assay employing the recombination signal sequence (RSS). Secondary Ig light chain rearrangement in the RAG-expressing B cells was confirmed by linker-mediated (LM)-PCR. Highly purified surface κ+ B cells activated by SAC + IL-2 became RAG+, and thereafter they started to express λ chain mRNA. 2 colour immunofluorescence analysis disclosed that a part of the RAG+ cells derived from the purified κ+ B cells activated by SAC + IL-2 turned to λ+ phenotype in vitro. Similarly, apoptosis induction was observed in a part of the RAG+ B cells. Our study suggests that a majority of peripheral blood B cells re-expresses RAG and the RAG+ B lymphocytes could be eliminated from the B cell repertoire either by changing Ag receptor specificity due to secondary rearrangement or by apoptosis induction. Thus, RAG expression of mature B cells in peripheral blood would contribute to not only receptor revision for further diversification of B cell repertoire but in some cases (or in some B cell subsets) to prevention or induction of autoAb responses at this differentiation stage in humans.
Unravelling the genetic complexity of autoimmune thyroid disease: HLA, CTLA-4 and beyond
Authors: SIMMONDS M J , GOUGH S C L 
Published: March 2004

SUMMARY
The autoimmune thyroid diseases (AITDs) including Graves’ disease (GD) and autoimmune hypothyroidism (AIH) are the commonest of the autoimmune conditions affecting 2–5% of the western population. Twin studies have clearly demonstrated that AITDs are caused by a combination of both environmental and genetic factors. Association of the HLA class II region with AITD has been documented for over 20 years now, but the primary aetiological variant in this region remains unknown. More recently the CTLA-4 gene region has been identified as the second locus conferring susceptibility to AITD. In contrast to HLA, a polymorphism of the CTLA-4 gene, which encodes an important negative regulator of the immune system, has been identified as a candidate for a primary determinant for AITD. A large number of candidate gene and genome wide linkage studies have been involved in the search for the elusive ‘third’ locus. The thyroglobulin (Tg) gene in humans maps to chromosome 8q, which has been linked in family studies to AITD. A number of association studies in humans and the mouse model for AITD are beginning to implicate the Tg gene although convincing evidence for a primary causative role is still needed. The establishment of large DNA disease resources along with more detailed genetic maps and the development of faster, more effective, high throughput genotyping and sequencing methods, provides some sense of optimism that novel loci will be identified in the near future and the complex aetiology of AITD will be further unraveled.
Pedagogical underpinnings of computer‐based learning
Authors: Adams Audrey M. 
Published: March 2004

Background.  E‐learning is becoming increasingly incorporated into educational programmes. Digital materials usually require a lot of investment in terms of time, money and human resources. With advances in technology, delivery of content has much improved in terms of multimedia elements. However, often only low‐level learning is achieved as a result of using these materials.Aim.  The purpose of this article is to give a comprehensive overview of some of the most important issues to consider when incorporating e‐learning into educational programmes.Discussion.  Computer‐based learning has three components: hardware, software and ‘underware’, the pedagogy that underpins its development. The latter is the most important, as the approach adopted will influence the creation of computer‐based learning materials and determine the way in which students engage with subject matter. Teachers are responsible for the quality of their courses and have a vital role in helping to develop the most appropriate electronic learning activities that will facilitate students to acquire the knowledge and skills necessary for clinical practice. Therefore, they need to have an awareness of what contributes to educationally effective, computer‐based learning materials.
Older people with depression: pilot study
Authors: Minardi Henry A. , Blanchard Martin 
Published: March 2004

Background.  Although a substantial number of studies have identified the prevalence of depression experienced by older adults living in the community and the factors that may precipitate this depression, few have focussed on depression in older people who attend day centres. Consequently, there is no literature suggesting how depression in this population may be psychologically managed.Aims.  The aim of this paper is to present the results of a pilot study investigating the incidence of depression in people attending a London Age Concern day centre, and its associations with perceptions of handicap, loneliness, social support networks, satisfaction with social support, and satisfaction with life.Methods.  A quasi‐experimental, cross‐sectional pilot study was conducted with attendees at a London Age Concern day centre between November 1998 and January 1999. The day centre manager selected a convenience sample of 24 of 156 participants. Inclusion criteria were that participants must attend the day centre regularly and be over or equal to 65 years of age. The exclusion criterion was known psychiatric illness. Participants were interviewed using the Geriatric Mental State‐Automated Geriatric Examination for Computer Assisted Taxonomy, which identifies caseness of psychopathology and includes a loneliness subscale, and completed the Satisfaction with Life Scale, Social Support Questionnaire and London Handicap Scale.Results.  There was a higher level of depression in this day centre setting than that found in other community‐based studies. There were the expected significant associations between depression and loneliness, and depression and satisfaction with life. However, unexpectedly, there were no associations between depression and social support, or depression and handicap.Conclusions.  The study has several limitations. However, the high level of depression and significant relationships between depression, loneliness and satisfaction with life may indicate that the social function of day centres is not meeting expectations. This suggests that there could be a role for community mental health nurses in offering psychosocial interventions to alleviate some of the distress experienced.