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Item does not contain fulltext Development of human cervical carcinomas is associated with infection by certain human papillomavirus (HPV) types. Thus, protection against HPV infection through vaccination may prevent development of cervical cancer. The purpose of this study was to investigate the possibility of using a poliovirus recombinant vector to induce immunity against HPV. A poliovirus recombinant was constructed which contained the complete coding sequence of the HPV 16 major capsid protein L1, between the P1 and P2 region of the poliovirus polyprotein. A replication-competent virus was obtained after transfection of the recombinant RNA into tissue culture cells. Electron microscopically examination of cells infected with the poliovirus-HPV L1 recombinant indicated that HPV 16 L1 self-assembles into virus-like particles. To investigate the immunological response in vivo, susceptible transgenic mice carrying the poliovirus receptor were infected with the recombinant poliovirus. In all mice a modest but consistent immune response against HPV 16 was observed. Based on these results, the potential for picornavirus-derived vectors in vaccine development against HPV infection is discussed.

Item does not contain fulltext Exposure of organotypic rat corticostriatal slice cultures to the mitochondrial toxin 3-nitropropionic acid (3-NP) resulted in concentration-dependent loss of cresylviolet-stained cells and increase of lactate dehydrogenase and lactate efflux into the culture medium, indicators for cell death and metabolic activity in the slices, respectively. The involvement of apoptosis in these slices was suggested by using the terminal transferase-mediated biotinylated-UTP nick end-labeling (TUNEL) technique, and immunohistochemistry for the apoptosis-related markers Bax and Bcl-2. In 3-NP-exposed slices, TUNEL-positive cells were observed in both the striatum and the cortex but in different forms: striatal neurons were either diffusely stained or showed nuclear fragmentation, cortical neurons only exhibiting nuclear fragmentation. In 3-NP-exposed slices, the pro-apoptotic protein Bax was abundantly expressed, whereas the anti-apoptotic protein Bcl-2 was not expressed in striatal neurons. We suggest that both apoptosis and necrosis are involved in the 3-NP-treated slices, apoptosis as well as necrosis in the striatum and apoptosis in the cortex.

Item does not contain fulltext The pathogenesis of the epidemic form of hemolytic uremic syndrome is characterized by endothelial cell damage. In this study, the role of apoptosis in verocytotoxin (VT)-mediated endothelial cell death in human glomerular microvascular endothelial cells (GMVEC), human umbilical vein endothelial cells, and foreskin microvascular endothelial cells (FMVEC) was investigated. VT induced apoptosis in GMVEC and human umbilical vein endothelial cells when the cells were prestimulated with the inflammatory mediator tumor necrosis factor-alpha (TNF-alpha). FMVEC displayed strong binding of VT and high susceptibility to VT under basal conditions, which made them suitable for the study of VT-induced apoptosis without TNF-alpha interference. On the basis of functional (flow cytometry and immunofluorescence microscopy using FITC-conjugated annexin V and propidium iodide), morphologic (transmission electron microscopy), and molecular (agarose gel electrophoresis of cellular DNA fragments) criteria, it was documented that VT induced programmed cell death in microvascular endothelial cells in a dose- and time-dependent manner. Furthermore, whereas partial inhibition of protein synthesis by VT was associated with a considerable number of apoptotic cells, comparable inhibition of protein synthesis by cycloheximide was not. This suggests that additional pathways, independent of protein synthesis inhibition, may be involved in VT-mediated apoptosis in microvascular endothelial cells. Specific inhibition of caspases by Ac-Asp-Glu-Val-Asp-CHO, but not by Ac-Tyr-Val-Ala-Asp-CHO, was accompanied by inhibition of VT-induced apoptosis in FMVEC and TNF-alpha-treated GMVEC. These data indicate that VT can induce apoptosis in human microvascular endothelial cells.

Item does not contain fulltext This report describes the preparation of an immunotoxin-combination, consisting of an anti-CD3 and anti-CD7 monoclonal antibody (MoAb) both conjugated to the A-chain of plant toxin ricin, for the experimental treatment of graft-versus-host disease. MoAbs and toxin were conjugated by conventional biochemical and chromatographic techniques. Raw materials, intermediate and final products were evaluated in accordance with the relevant 'points to consider' of the FDA. Yields, purity and sterility of the two final products were all satisfactory. Preservation of MoAb-affinity and toxin-activity were confirmed in biological assays. The LD50, 25-45 mg immunotoxin-combination/kg mouse, equalled that of similar immunotoxins already in clinical use. Because in vitro cross-reactivity screening revealed an unexpected binding of the CD3-MoAb to the esophagus epithelium, human doses of immunotoxin-combination were administered to two cynomolgus monkeys. Clinically relevant serum concentrations were obtained without irreversible toxicities occurring. The T(1/2) varied between approximately 6 and 9 h and the C(max) ranged from 1.8 to 3.9 microg/ml. The main side effect was a transient rise of serum creatine kinase. Importantly, neither damage nor binding of the CD3-immunotoxin to the monkey esophagus epithelium could be demonstrated. It was concluded that sufficient material of proper quality and with an acceptable toxicity profile was produced, warranting the evaluation in a clinical pilot-study.

Contains fulltext : 185644.pdf (Publisher’s version ) (Closed access) BACKGROUND: Nephrotic syndrome in childhood is mainly due to minimal change nephropathy. In general, it is characterized by selective proteinuria, by steroid responsiveness, and histologically by podocytic foot process effacement. Familial presentation is rare and mainly restricted to one generation. METHODS: We describe the occurrence of a familial nephropathy in a mother and two daughters. An initial diagnosis of minimal change nephropathy was made, but subsequently unique features became apparent. During follow-up, detailed studies of renal function and urinary protein excretion were performed. Available frozen renal biopsy material was revised and processed for immunofluorescence to detect abnormalities in the expression of heparan sulfate proteoglycans. The latter results were compared with renal biopsies of a control group composed of five adult patients with minimal change nephropathy. RESULTS: The mother and two daughters were proteinuric since their early childhood. The mother revealed a persistent nephrotic syndrome for more than 20 years despite treatment with various immunosuppressive drugs. Likewise, treatment with prednisone was ineffective in the daughters. All three patients retained normal renal function during follow-up. Detailed measurements revealed that the proteinuria was incredibly selective (selectivity index approximately 0.01), and there was no evidence of tubulointerstitial damage, as reflected by a normal excretion of the low-molecular weight proteins beta(2)-microglobulin and alpha1-microglobulin. Renal biopsy performed in the mother and one daughter was thought to be compatible with minimal change nephropathy. However, histologically, two remarkable findings were made. By electron microscopy, there was no evidence of foot process retraction; specifically, the foot process width and slit pore diameter were normal. Furthermore, in contrast to the control patients, the expression of heparan sulfate polysaccharide side chains, as reflected by the staining with monoclonal antibody JM403, was normal. CONCLUSIONS: We propose that this family represents a new familial nephropathy. The molecular basis of the permeability defect remains to be identified.

Item does not contain fulltext BACKGROUND: The outcome of renal transplantation in patients with IgA nephropathy (IgAN) may be affected by recurrence of the original disease. Despite this risk of recurrent glomerulonephritis, graft survival in patients with IgAN is considered good although formal comparisons with graft survival in patients with other renal diseases have given conflicting results. METHODS: We have studied both recurrence rate and outcome after renal transplantation in 79 adult patients with IgAN, all of whom received a first renal graft (55 cadaveric, 24 living-related donor) in our center in the period between 1969 and 1997. Graft survival in patients with IgAN was compared with the outcome in patients with pyelonephritis and adult polycystic kidney disease (group 2) and patients with non-IgA primary glomerulonephritis (group 3). RESULTS: Follow-up averaged 5.6 +/- 4.5 years. Histological evidence of mesangial IgA deposits was present in 17 of 32 available biopsies (53%). Clinically recurrent IgAN was diagnosed only in 7 patients (9% of all recipients), with a higher incidence in recipients of a living-related donor graft (5/24 (20%) vs 2/55 (4%)). These recurrences were diagnosed in biopsies taken 13-145 months after transplantation; and all were characterized by significant proteinuria (> 1 g/day). In only one patient the graft was lost due to the recurrence. For recipients of a cadaveric graft, the 5-year graft survival was significantly better in IgAN patients than in both reference groups (86% vs 67% in group 2; p = 0.012, and 60% in group 3; p = 0.007). This difference remained significant after censoring for death. There was no statistically significant difference in the patient survival between the groups. The rejection rate in the first 3 months was numerically lower in the IgAN patients (37% vs 43% and 49%, respectively). and total immunological failure rate was also lower in the IgAN patients compared to the control groups (13% vs 21% and 23%, respectively); although the differences were not statistically significant. The 5- and 10-year graft survival in recipients of living-related donor grafts was significantly better in IgAN patients than in group 3 (96% and 84% vs 64% and 21%, respectively; p = 0.02), but similar to graft survival in group 2 (87% and 75%). CONCLUSION: A clinical recurrence of IgAN occurred in 4% of patients with a cadaveric donor graft and 20% of patients with a living-related donor graft. The recurrence had negligible influence on 5- and 10-year graft survival. Graft survival after cadaveric transplantation was better in the IgAN patients compared to control groups; possibly due to the lower immunological failure rate in IgAN.

Item does not contain fulltext Explanted hearts were examined to determine whether specific histopathologic features are present in the myocardium of patients with end-stage idiopathic dilated cardiomyopathy (IDC). Extensive histopathologic examination by light microscopy, electron microscopy and immunohistochemistry revealed marked fibrosis in the hearts of 21 of 37 IDC patients and in 26 of 35 patients with heart diseases of known causes. Reactive (interstitial and perivascular) fibrosis predominated in the IDC hearts, whereas both reparative (replacement) fibrosis and reactive fibrosis were found in the comparison group. Endocardial fibroelastosis was found in nine patients with IDC and in 14 patients from the comparison group. Distinct patterns of fibrosis were the sole significant histopathologic difference between myocardial samples from patients with IDC and from those with heart diseases of known causes. The diffuse presence of reactive fibrosis in IDC patients suggests a more generalised dysfunction that affects the composition of the myocardial extracellular matrix.

Previously we have shown that synovial lining macrophages (SLMs) determine the onset of experimental immune complex–mediated arthritis (ICA). During joint inflammation, many leukocytes undergo apoptosis, and removal of leukocytes by SLMs may regulate resolution of inflammation. In this study we investigated binding and uptake of apoptotic leukocytes by SLMs and its impact on the onset of murine experimental arthritis. We used an in vitro model to evaluate phagocytosis of apoptotic cells on chemotaxis. Phagocytosis of apoptotic thymocytes resulted in a significant decrease (58%) of chemotactic activity for polymorphonuclear neutrophils (PMNs). If apoptotic cells were injected directly into a normal murine knee joint, SLMs resulted in a prominent uptake of cells. After ICA induction, electron micrographs showed that apoptotic leukocytes were evidently present in SLMs on days 1 and 2. Injection of apoptotic leukocytes into the knee joint 1 h before induction of ICA significantly inhibited PMN infiltration into the knee joint at 24 h (61% decrease). This study indicates that uptake of apoptotic leukocytes by SLM reduces chemotactic activity and inhibits the onset of experimental arthritis. These findings indicate an important mechanism in the resolution of joint inflammation.

Contains fulltext : 185560.pdf (Publisher’s version ) (Closed access) BACKGROUND: Endogenous nitric oxide protects against airway hyperresponsiveness (AHR) to bradykinin in mild asthma, whereas AHR to bradykinin is enhanced by inhaled allergens. OBJECTIVE: Hypothesizing that allergen exposure impairs bronchoprotective nitric oxide within the airways, we studied the effect of the inhaled nitric oxide synthase (NOS) inhibitor N(G)-monomethyl-L-arginine (L-NMMA) on AHR to bradykinin before and after allergen challenge in 10 subjects with atopic asthma. METHODS: The study consisted of 3 periods (1 diluent and 2 allergen challenges). AHR to bradykinin (PD(20)BK) was examined before and 48 hours after allergen challenge, both after double-blinded pretreatment with L-NMMA or placebo. The accompanying expression of the various NOS isoforms (ecNOS, nNOS, and iNOS) was examined by means of immunohistochemistry in bronchial biopsies obtained after diluent and allergen challenge. RESULTS: After placebo, AHR to BK worsened after allergen challenge in comparison with before allergen challenge (PD(20)BK, 70.8 nmol [range, 6.3-331] and 257 nmol [35.5-2041], respectively; P =.0004). After L-NMMA, preallergen and postallergen PD(20)BK values (50.1 nmol [1.8-200] vs 52.5 nmol [6.9-204]; P =.88) were similarly reduced (P .05). After allergen challenge, the intensity of staining in bronchial epithelium decreased for ecNOS (P =.03) and increased for iNOS (P =.009). These changes in immunostaining were correlated with the accompanying worsening in AHR to BK (R(s) = -0.66 and 0.71; P

Item does not contain fulltext The mitochondrial toxin 3-nitropropionic acid (3-NP) causes selective striatal lesions in rats and serves as an experimental model for the neurodegenerative disorder Huntington's disease (HD). Apoptotic cell death has been implicated for the neuronal degeneration that occurs in HD brains. The present study was designed to investigate whether the 3-NP-induced cell death in rats involves apoptosis and an altered expression of Bcl-2 family proteins. Systemic administration of 3-NP via subcutaneous Alzet pumps resulted in lesions of variable severity with neuronal loss and gliosis in the striatum. Using the terminal transferase-mediated biotinylated-UTP nick end-labelling (TUNEL) of DNA, TUNEL-positive cells exhibiting typical apoptotic morphology were detected only in the striatum of rats with a severe lesion. Furthermore, the neuronal expression of the pro-apoptotic protein Bax was strongly increased in the core of the severe lesion. Expression of the anti-apoptotic marker Bcl-2 was unchanged in this location, but was enhanced in the margins of the lesions. A moderately increased expression of both Bax and Bcl-2 was observed in dark neurones in the mild lesion and in the subtle lesion. The presence of nuclear DNA fragmentation, strong granular Bax expression and an increased Bax/Bcl-2 ratio in the centre of severe lesions suggests the occurrence of apoptotic cell death following 3-NP administration. In contrast, the dark compromised neurones observed in 3-NP-treated animals revealed an equally enhanced expression of both Bax and Bcl-2, but lacked TUNEL-labelling, and are therefore not apoptotic.

Item does not contain fulltext Low-molecular-weight heparins are routinely used to prevent deep venous thrombosis following renal transplantation in our department. We report 2 patients who developed tender erythematous subcutaneous nodules with induration, ulceration and necrosis at the site of subcutaneous administration of nadroparin. Both patients were renal transplant recipients with impaired graft function and high serum calcium-phosphate products. The diagnosis calcinosis cutis was confirmed by technetium-99m bone scan and by histological examination of biopsies. Both patients showed spontaneous recovery several weeks after discontinuation of nadroparin. Patients with chronic renal failure and hyperphosphatemia may be predisposed to develop calcinosis cutis. In addition, the role of the calcium content of nadroparin is discussed.

Background. Angiotensin II (ANG II) is a major factor involved in the progression of chronic renal disease, Although the generation of this vasoactive peptide has been investigated in great detail, only a few studies have hitherto addressed the metabolism of ANG II into fragments such as angiotensin III and IV (ANG III, IV) which may exert physiological effects independent of ANG II. Aminopeptidase A (APA) is the major enzyme degrading ANG II. The aim of the current study was to evaluate glomerular APA expression in rats with two-kidney, one-clip hypertension. Methods. The left renal artery was restricted with a 0.2-mm silver clip. Kidneys were harvested 1 and 4 weeks after surgery. APA enzyme and protein expression was evaluated in kidney sections. Total APA enzyme activity and mRNA expression was assessed in isolated glomeruli. Degradation of exogenous ANG II by isolated glomeruli was measured with reverse-phase high-performance liquid chromatography. Results. APA enzyme activity, protein, and mRNA expression were stimulated in the clipped kidney 1 week after surgery compared with the contralateral kidney or normal controls. In contrast, 4 weeks after clipping APA activity and expression was higher in the contralateral kidney. In parallel to these findings, degradation of ANG II was greatest in isolated glomeruli obtained from the clipped kidney after 1 week. However, preparations from the contralateral kidney 4 weeks after surgery were more active in the metabolism of exogenous ANG II. Conclusion. The present study provides evidence that APA is complexly regulated in in vivo situations with an activated local renin-ANG II system. ANG II appears to play a direct role in this regulation. However, since conversion of ANG II to ANG III by APA is the initial step leading to the formation of ANG IV which may exert detrimental effects not mediated through classical ANG II receptors, a local increase in APA activity may contribute to the progression of chronic renal disease even during complete AT 1 -receptor blockade.

Nitric oxide (NO) radicals generated by endothelial nitric oxide synthase (eNOS) are involved in the regulation of vascular tone. In addition, NO radicals derived from eNOS inhibit platelet aggregation and leukocyte adhesion to the endothelium and, thus, may have anti-inflammatory effects. To study the role of eNOS in renal inflammation, the development of accelerated anti-glomerular basement membrane (GBM) glomerulonephritis was examined in mice lacking a functional gene for eNOS and compared with wild-type (WT) C57BL/B6j mice. WT C57BL/6j mice (n = 12) and eNOS knockout (−/−) mice (n = 12) were immunized intraperitoneally with sheep IgG (0.2 mg in complete Freund’s adjuvant). At day 6.5 after immunization, mice received a single i.v. injection of sheep anti-mouse GBM (1 mg in 200 μl PBS). Mice were sacrificed at day 1 and 10 after induction of the disease. All WT mice survived until day 10, whereas 1 eNOS−/− mouse died and 2 more became moribund, requiring sacrifice. At day 10, eNOS−/− mice had higher levels of blood urea nitrogen than WT mice (P < 0.02), although proteinuria was comparable. Immunofluorescence microscopy documented similar IgG deposition in both WT and eNOS−/− mice, but eNOS−/− mice had more extensive glomerular staining for fibrin at day 10 (P < 0.007). At day 10, light microscopy demonstrated that eNOS−/− mice had more severe glomerular thrombosis (P < 0.003) and influx of neutrophils (P < 0.006), but similar degrees of overall glomerular endocapillary hypercellularity and crescent formation. In conclusion, accelerated anti-GBM glomerulonephritis is severely aggravated in eNOS−/− mice, especially with respect to glomerular capillary thrombosis and neutrophil infiltration. These results indicate that NO radicals generated by eNOS play a protective role during renal inflammation.

Background. Focal glomerulosclerosis (FGS) can recur after renal transplantation and prognosis is poor in untreated patients. A circulating plasma factor has been implicated in the pathogenesis of a recurrent FGS and treatment with plasma exchange has proven effective in decreasing proteinuria in some patients. Methods. We retrospectively studied the course of disease in patients with recurrent FGS, transplanted in our centre. Seven patients transplanted between 1991 and 1997, received treatment with plasma exchange, whereas 10 patients, transplanted between 1973 and 1991, were left untreated and served as historical controls. Results. The time of onset of proteinuria (> 3.5 g/day) was comparable in the untreated and treated patients (9 and 10 days respectively), as was the average proteinuria at that time (5.5 and 5.8 g/day respectively). In the untreated patients, proteinuria persisted and eventually all grafts were lost, on average 43 months after the diagnosis of a recurrence. In five cases (50%) the recurrence was the single cause of graft loss. The clinical course was different in the seven patients who were treated with plasma exchange. In five of these patients, the recurrence occurred within 3 weeks after transplantation. Plasma exchange was started 1-14 days after onset of proteinuria in these patients. Two lost their grafts after 0.7 and 1.0 months because of untreatable rejection. In the remaining three patients the plasma exchange resulted in abrupt disappearance of the proteinuria, and the response has been lasting for 2-3.2 years. In these patients the only histological abnormality was foot effacement on electron-microscopy. In two patients the recurrence became manifest at 9 weeks and 5.8 years after transplantation respectively. These two patients relapsed after the initial course of plasma exchange, but responded to repeated session, and are currently being treated once a month. They have been followed for 1.7 and 1.4 years after the onset of proteinuria and their urinary protein levels are 0.23 and 1.2 g/10 mmol creatinine. Conclusions. The prognosis of untreated recurrent FGS is poor. Treatment with plasma exchange can lead to complete remission of proteinuria and relapsing patients may respond to repeated sessions. Best results are obtained when plasma exchange is started early, when there are no visible lesions on light-microscopy.

To investigate the involvement of NADPH-diaphorase (NADPH-d)-containing neurons in Alzheimer's disease (AD), NADPH-d enzyme histochemistry in vibratome sections was applied to the superior frontal and superior temporal cortex and the neostriatum in 5 AD and 6 aged control brains. Overall there was a neuronal loss and atrophy in the cortex of AD. Despite slight morphological neuronal changes in the cortex of AD, we found no significant difference in the number of NADPH-d-positive neurons in both cortex and neostriatum between control and AD cases. These results provide further evidence for a selective preservation of NADPH-d neurons in AD. In order to check whether nNOS-immunoreactive neurons are identical to NADPH-d-positive neurons in the human brain, we examined the frontal and temporal cortex and neostriatum of normal human brains in serial cryostat sections. We found that nNOS-containing neurons paralleled NADPH-d-positive neurons in these brain regions. Copyrightz1999S.KargerAG,Basel

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Agrin is a heparan sulfate proteoglycan (HSPG) that is highly concentrated in the synaptic basal lamina at the neuromuscular junction (NMJ). Agrin-like immunoreactivity is also detected outside the NMJ. Here we show that agrin is a major HSPG component of the human glomerular basement membrane (GBM). This is in addition to perlecan, a previously characterized HSPG of basement membranes. Antibodies against agrin and against an unidentified GBM HSPG produced a strong staining of the GBM and the NMJ, different from that observed with anti-perlecan antibodies. In addition, anti-agrin antisera recognized purified GBM HSPG and competed with an anti-GBM HSPG monoclonal antibody in ELISA. Furthermore, both antibodies recognized a molecule that migrated in SDS-PAGE as a smear and had a molecular mass of approximately 200-210 kD after deglycosylation. In immunoelectron microscopy, agrin showed a linear distribution along the GBM and was present throughout the width of the GBM. This was again different from perlecan, which was exclusively present on the endothelial side of the GBM and was distributed in a nonlinear manner. Quantitative ELISA showed that, compared with perlecan, the agrin-like GBM HSPG showed a sixfold higher molarity in crude glomerular extract. These results show that agrin is a major component of the GBM, indicating that it may play a role in renal ultrafiltration and cell matrix interaction. (J Histochem Cytochem 46:19-27, 1998)

Intercellular adhesion molecule-1 (ICAM-1) expression is upregulated in nephrotoxic nephritis, a model of human rapidly progressive glomerulonephritis. To evaluate the pathogenetic relevance of ICAM-1 in this model, nephrotoxic nephritis was induced in ICAM-1 knockout mice and genetic controls. Mice were preimmunized with rabbit IgG in complete Freund's adjuvant. Seven days later they received rabbit anti-mouse glomerular basement membrane IgG. The early humoral immune responses (levels of circulating mouse anti-rabbit IgG, glomerular deposition of rabbit and mouse IgG and mouse C3c) were not altered in ICAM-1 knockout mice. During 28 d of follow-up, 3 of 19 control nephritic mice and 0 of 16 ICAM-1 knockout mice died. Proteinuria was high in nephritic control mice (means 10 to 12 mg/24 h at all time points investigated) and significantly reduced in nephritic ICAM-1 knockout mice (means4.4 mg). Mean serum creatinine rose from 29 micromol/L at day -7 to 48 micromol/L (day 28) in nephritic control mice. This increase in serum creatinine was significantly lower in ICAM-1 knockout mice: 27 (day -7) and 36 micromol/L (day 28). Histologic analysis at day 28 revealed that ICAM-1 deficiency in nephrotoxic nephritis mice led to significantly reduced glomerular crescent formation (2+/-3% in ICAM-1 knockout mice versus 13+/-8% in nephritic controls) and tubulointerstitial injury (score 0.4+/-0.4 versus 2.0+/-1.1). By immunohistochemistry, ICAM-1 deficiency in nephritic mice led to significantly reduced (peri-)glomerular and/or interstitial macrophage influx, alpha-smooth muscle actin expression, and type IV collagen accumulation. These data indicate that ICAM-1 is a central mediator of glomerular and tubulointerstitial injury in murine nephrotoxic nephritis.

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Patient: A 39-year-old woman with mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS) who developed paralytic ileus and died of irreversible shock. Methods: Abdominal X-ray, autopsy using light microscopy, electron microscopy and mitochondrial DNA analysis. Results: Paralytic ileus was diagnosed. Several hours after admission the patient died from irreversible shock. At autopsy, ultrastructural examination of the small intestine revealed abnormal accumulation of mitochondria in smooth muscle cells. DNA analysis of the intestinal tissue showed a tRNALeu(UUR) A→G transition at nucleotide position 3243 of the mitochondrial DNA. The amount of mutated mitochondrial DNA was markedly higher in the lamina muscularis than in the mucosa: 30% vs. 8%. Conclusions: Paralytic ileus may be due to mutated mitochondrial DNA which ultimately leads to smooth muscle dysfunction in the small intestine. Recognizing mitochondrial DNA abnormalities as a new etiopathogenetic factor of paralytic ileus may become more important in clinical medicine in the near future.

Mac-1 (alphambeta2), a leukocyte adhesion receptor, has been shown in vitro to functionally interact with Fcgamma receptors to facilitate immune complex (IC)-stimulated polymorphonuclear neutrophil (PMN) functions. To investigate the relevance of Mac-1-FcgammaR interactions in IC-mediated injury in vivo, we induced a model of Fc-dependent anti-glomerular basement membrane (GBM) nephritis in wild-type and Mac-1-deficient mice by the intravenous injection of anti-GBM antibody. The initial glomerular PMN accumulation was equivalent in Mac-1 null and wild-type mice, but thereafter increased in wild-type and decreased in mutant mice. The absence of Mac-1 interactions with obvious ligands, intercellular adhesion molecule 1 (ICAM-1), and C3 complement, is not responsible for the decrease in neutrophil accumulation in Mac-1- deficient mice since glomerular PMN accumulation in mice deficient in these ligands was comparable to those in wild-type mice. In vitro studies showed that spreading of Mac-1-null PMNs to IC-coated dishes was equivalent to that of wild-type PMNs at 5-12 min but was markedly reduced thereafter, and was associated with an inability of mutant neutrophils to redistribute filamentous actin. This suggests that in vivo, Mac-1 is not required for the initiation of Fc-mediated PMN recruitment but that Mac-1-FcgammaR interactions are required for filamentous actin reorganization leading to sustained PMN adhesion, and this represents the first demonstration of the relevance of Mac-1-FcgammaR interactions in vivo. PMN-dependent proteinuria, maximal in wild-type mice at 8 h, was absent in Mac-1 mutant mice at all time points. Complement C3-deficient mice also had significantly decreased proteinuria compared to wild-type mice. Since Mac-1 on PMNs is the principal ligand for ic3b, an absence of Mac-1 interaction with C3 probably contributed to the abrogation of proteinuria in Mac-1-null mice.

Aims—To assess the course of tear gland function of patients with keratoconjunctivitis sicca (KCS) associated with primary (KCS-PSS) or secondary Sjogren’s syndrome (KCS-SSS), and of patients with KCS not related to Sjogren’s syndrome (KCS-NS). Methods—In 106 patients with dry eye an ophthalmic diagnosis of KCS was made. Subsequent evaluations revealed a diagnosis of KCS-PSS in 31, KCS-SSS in 19, and KCS-NS in 56 patients. Follow up assessments have been performed 10‐12 years after initial diagnosis. Results—At baseline and at follow up tear gland function tests were worse in patients with KCS-PSS compared with the other forms of KCS. At follow up in the KCS-SSS patient group the tear gland function variables returned to marginal normal limits. In contrast with expectation, a marked improvement of the tear gland function variables in the KCS-NS patient group was noted. Conclusions—In KCS-PSS patients tear gland function is characterised by a steady state situation. In KCS-SSS patients the normalisation of tear gland function variables most probably reflects a remission of the underlying disease. In view of the overall improvement in KCS-NS patients the term age related KCS should be avoided. (Br J Ophthalmol 1997;81:435‐438)

Effects of TNFα and verocytotoxin cytotoxicity in human glomerular microvascular endothelial cells. In the pathogenesis of the hemolytic uremic syndrome (HUS), endothelial damage of glomeruli and arterioles of the kidney appears to play a central role. Previous studies have shown that verocytotoxin-1 (VT-1) cytotoxicity on human vein endothelial cells require additional stimuli, in particular the inflammatory mediator tumor necrosis factor alpha (TNFα). In this study the effects of VT on human glomerular microvascular endothelial cells (GMVEC) were examined. A reproducible method was developed for the isolation and purification of large numbers of highly purified GMVEC. The obtained GMVEC were over 99% pure; their endothelial origin was demonstrated by the expression of the endothelial antigens von Willebrand factor, EN-4, PECAM-1 and V,E-cadherin. Upon stimulation with TNFα the cells expressed the endothelial-specific adhesion molecule E-selectin. A limited number of fenestral structures was observed by scanning electron microscopy (SEM), suggesting glomerular origin of the endothelial cells. Cytotoxicity of VT-1 to GMVEC was evaluated by determination of the number of viable adherent cells and by assay of overall protein synthesis after exposure to varying concentrations of VT-1. In non-stimulated GMVEC, cytotoxicity of VT-1 was inversely related to the degree and duration of confluence, subconfluent cells being the most sensitive. In highly confluent GMVEC, VT cytotoxicity required pre-exposure of the cells to the inflammatory mediator TNFα, which induced an increase in the number of VT receptors on GMVEC. Thin layer chromatography of extracted glycolipids from the GMVEC showed binding of VT-1 to globotriaosylceramide (Gb3), known to be the functional receptor for VT. There were no major differences in protein synthesis inhibition with equal concentrations VT-1 and VT-2. In conclusion, in this study we provide a reproducible method to isolate, purify and culture well characterized human GMVEC on a routine basis. In vitro studies with these GMVEC demonstrate that VT cytotoxicity depends on the degree of confluence and the additional preexposure to the inflammatory mediator TNFα. These observations provide further insight into the complex events that may occur in glomeruli in the pathogenesis of HUS.

Heparan sulfate proteoglycans (HSPGs) are essential components of the glomerular basement membrane (GBM) carrying a strong anionic charge. A well- characterized extracellular HSPG is perlecan, ubiquitously expressed in basement membranes. A cDNA construct encoding domains I and II of human perlecan was expressed as a fusion protein with glmathione S-transferase. This fusion protein was used to generate monoclonal antibody 95J10. We compared the staining pattern of 95J10 with that of M215, a previously prepared mAb that recognizes HSPG isolated from human GBM. In kidney cortex, the antiperlecan mAb 95J10 showed a strong staining of the mesangium, Bowman's capsule, the tubular basement membrane, and stained the GBM only slightly. In contrast, M215 predominantly stained the GBM in a linear fashion. Immunoelectron microscopy supported these results, showing concentrations of perlecan in some regions of the GBM, whereas the unidentified M215 antigen was homogemously distributed throughout the GBM. In other human tissues, both antibodies also produced a different staining pattern. Furthermore, a polyclonal antiserum recognizing HSPG isolated from the GBM did not recognize perlecan from EHS tumors. These results provide evidence for the presence of another HSPG in the GBM that is immunologically distinct froth perlecan. The absence of perlecan splice variants in the kidney suggests that this component is encoded by a different gene than perlecan. Given its marked expression in the GBM, this component could be a determining factor in the maintenance of selective glomerular permeability.

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A fatal case of a pulmonary infection caused by Hormographiella aspergillata, the anamorph of the mushroom Coprinus cinereus, is reported for a patient receiving treatment for a second relapse of acute lymphoblastic leukemia. The filamentous basidiomycete was identified with restriction fragment length polymorphism patterns of PCR-amplified internally transcribed spacers and small subunit ribosomal DNA with four restriction enzymes. The patient failed to respond to treatment with amphotericin B and itraconazole. The fungus was cultured from the lungs at autopsy: the MIC of amphotericin B for the fungus was low (0.5 mg/liter), and that of itraconazole was high (8 mg/liter).

Acute passive anti-glomerular basement membrane nephritis in P-selectin-deficient mice . P-selectin present on surfaces of activated endothelium and platelets mediates neutrophil-endothelial and neutrophil-platelet interactions. The role of P-selectin in vivo was examined in a model of acute passive anti-GBM nephritis in P-selectin-deficient and wild-type mice which was induced by intravenous injection of anti-GBM serum. There were two major differences between P-selectin-deficient and wild-type mice. Firstly, mutant mice had approximately two fold more glomerular PMNs and albuminuria than wild-type animals at the peak of neutrophil influx and proteinuria. Secondly, Lipoxin A 4 (LXA 4 ), an eicosanoid which inhibits leukocyte-endothelial adhesion in vitro , and is generated primarily by transcellular biosynthetic routes during P-selectin-mediated platelet-PMN interaction [1], was approximately 60% of wild type levels in nephritic kidneys of P-selectin-deficient mice. Injection of wild-type platelets into P-selectin-null mice restored LXA 4 to wild-type levels. The corresponding PMN influx approximated PMN levels in wild-type mice receiving platelets but urine albuminuria remained higher. Although these two P-selectin-dependent events cannot be directly linked, our results point to the importance of considering both platelet and endothelial P-selectin in determining the cellular events in inflammation.

Heparin and heparinoids prevent the binding of immune complexes containing nucleosomal antigens to the GBM and delay nephritis in MRL/lpr mice. Monoclonal anti-nucleosome antibodies (mAbs) complexed to nucleosomal antigens can bind to DNA and to heparan sulfate (HS) in ELISA and to the GBM in vivo in a rat renal perfusion system, whereas non-complexed mAbs do not bind [1]. In this study, we analyzed whether heparin (HEP) or N-desulfated/acetylated heparins (DSA-HEP), structurally and functionally strongly related to HS, are able to prevent the binding of these complexed mAbs to DNA and to HS in vitro and to rat GBM in vivo. In ELISA the binding of nucleosome complexed anti-nucleosome antibodies to DNA and HS was inhibited dose-dependently by HEP, DSA-HEP and low molecular weight (LMW) DSA-HEP. Intravenous injection of nucleosome/anti-nucleosome immune complexes without heparin/heparinoids in BALB/c mice led to GBM binding, while simultaneous injection of heparin/heparinoids with complexed antibodies or pretreatment with heparin subcutaneously prior to injection of complexes prevented this binding. Subsequently, we tested the preventive effect of HEP, DSA-HEP and LMW-DSA-HEP on progression of renal disease in MRL/lpr mice. Treatment was started at an age of eight weeks in a dose of 50 µg daily. With all three drugs albuminuria was significantly delayed compared to PBS treated controls (cumulative incidence of proteinuria at 20 weeks in controls 60% vs. 13%, 14% and 6% respectively for HEP, DSA-HEP and LMW-DSA-HEP; P < 0.05). At week 21 the glomerulonephritis was histologically less severe in heparin/heparinoid treated animals (P = 0.02). In immunofluorescence the amount of immunoglobulin and C3 deposits in the glomerular capillary wall tended to be less in heparin/heparinoid treated mice compared to PBS treated controls (P = 0.07). Furthermore, at 20 weeks anti-HS levels in plasma of heparin/heparinoid treated mice were significantly lower (P < 0.05). We conclude that interaction of heparin or heparin analogs with HS reactive immune complexes containing nucleosomal antigens prevents the binding of these immune complexes to the GBM and delays nephritis in MRL/lpr mice.

The hypothalamic lateral tuberal nucleus (NTL) can be recognized in man and higher primates, only. The function of this nucleus is unknown, but the NTL is affected in a variety of human neurodegenerative diseases, including Huntington's disease (HD) and Alzheimer's disease. In the present study we demonstrate an abundant presence of somatostatin 1–12 (SSTI-12) immunoreactivity in both neurites and perikarya of the NTL. This immunoreactivity could be visualized best after microwave pretreatment. In HD brains, NTL SSTI-12 immunoreactivity was greatly reduced, providing further evidence of the presence of SSTI-12 as an intrinsic neuropeptide in the NTL. Although striatal SST neurons escape destruction in HD, our study demonstrates that not all SST neurons are resistant to the degenerative process in this disease.

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Heparan sulphate-associated anionic sites in the glomerular basement membrane were studied in rats 8 months after induction of diabetes by streptozotocin and in age- adn sex-matched control rats, employing the cationic dye cuprolinic blue. Morphometric analysis at the ultrastructural level was performed using a computerized image processor. The heparan sulphate specificity of the cuprolinic blue staining was demonstrated by glycosaminoglycan-degrading enzymes, showing that pretreatment of the sections with heparitinase abolished all staining, whereas chondroitinase ABC had no effect. The majority of anionic sites (74% in diabetic and 81% in control rats) were found within the lamina rara externa of the glomerular basement membrane. A minority of anionic sites were scattered throughout the lamina densa and lamina rara interna, and were significantly smaller than those in the lamina rara externa of the glomerular basement membrane (p

An unusual case is described of a patient with both anti-glomerular basement membrane (GBM) disease and anti-neutrophil cytoplasmic autoantibodies with myeloperoxidase specificity (MPO-ANCA) presenting with acute renal failure. Four years before a seronegative arthritis of the left wrist was diagnosed. Tests for ANCA by indirect immunofluorescence were repeatedly negative. The diagnosis was made by renal biopsy and by testing the serum with specific enzyme-linked immunosorbent assays (ELISA) for MPO-ANCA and anti-GBM antibodies. To our knowledge, this is the first patient presenting with such findings in the Dutch literature.

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Item does not contain fulltext A Dutch family with autosomal recessive early-onset parkinsonism showed a heterozygous missense mutation in combination with a heterozygous exon deletion in the parkin gene. Although the main clinical syndrome consisted of parkinsonism, the proband clinically had additional mild gait ataxia and pathologically showed neuronal loss in parts of the spinocerebellar system, in addition to selective loss of dopaminergic neurons in the substantia nigra pars compacta. Lewy bodies and neurofibrillary tangles were absent, but tau pathology was found.

A 2-month-old girl developed motor neuron disease (MND) with autonomic disturbances and died at the age of 5 months. Neuropathological examination revealed Bunina bodies (BBs) in the lower motor neurons of the lumbar spinal cord. The significance of the presence of BBs and the classification of the MND in this child are discussed.

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Antibody-induced albuminuria and accelerated focal glomerulosclerosis in the Thy-1.1 transgenic mouse. Background Podocytes play an important role in the development of proteinuria and focal glomerulosclerosis. Previously we have demonstrated that a combination of two monoclonal antibodies (mAb) against aminopeptidase A (APA), an enzyme present on podocytes, induces a massive acute albuminuria in mice. The present study examined the relationship between the acute antibody-induced albuminuria and the development of focal glomerulosclerosis in the Thy-1.1 transgenic mouse. This mouse expresses a hybrid human-mouse Thy-1.1 antigen on the podocytes, and slowly but spontaneously develops albuminuria and focal glomerulosclerosis. Methods Five-week-old non-albuminuric Thy-1.1 transgenic and non-transgenic control mice were injected with anti-APA and anti-Thy-1.1 mAb or saline. Albuminuria was measured at days 1, 7, 14 and 21. At day 21 kidneys were processed for light microscopy, immunofluorescence, and electron microscopy. Results Injection of anti-APA and anti-Thy1.1 mAb in Thy-1.1 transgenic mice induced an albuminuria at day 1 that persisted at day 21. The acute albuminuria after injection of anti-APA mAb was more prominent but transient in non-transgenic mice. In non-trangenic mice no albuminuria could be induced with anti-Thy 1.1 mAb. Light microscopy revealed normal glomeruli at day 1 in all transgenic mice, however, at day 21 advanced glomerulosclerotic lesions were seen in mice injected with either anti-APA mAb (37±19% of glomeruli affected) or anti-Thy-1.1 mAb (71±5%). Non-transgenic mice did not reveal sclerotic lesions at any time investigated. In the transgenic mice the percentage of focal glomerulosclerosis at day 21 did not correlate with albuminuria at day 21. However, we found a highly significant correlation between percentage of focal glomerulosclerosis and the time-averaged albuminuria over the three-week study period (P Conclusion Injection of a combination of anti-APA or anti-Thy-1.1 mAb into one mo old, non-albuminuric Thy-1.1 transgenic mice induces an acute albuminuria at day 1 that is accompanied by an accelerated focal glomerulosclerosis at day 21. We suggest that the Thy-1.1 transgenic mouse is an excellent model to study specifically the relation between podocytic injury, albuminuria and the development of focal glomerulosclerosis.

A protective role for endothelial nitric oxide synthase in glomerulonephritis. In acute glomerulonephritis (GN), increased nitric oxide (NO) production occurs, suggesting a pathophysiological role for NO in the disease process. Although NO potentially could have both toxic as well as protective effects, its exact role in the pathophysiology of GN is unclear and may depend on the NOS isoform generating NO. The protective effects of NO such as prevention of leukocyte and platelet activation and adhesion have been attributed to NO generated by endothelial nitric oxide synthase (eNOS). Evidence for a beneficial role for eNOS includes the demonstration of reduced eNOS expression in experimental models of GN as well as human biopsy specimens that is mostly likely due to endothelial cell necrosis. Reduced NO production in GN also may occur through reaction of NO with superoxide anions or the myeloperoxidase (MPO)/hypochlorous acid (HOCL) system. Further evidence has been provided by the observation that in several experimental models of GN, glomerular injury is exacerbated following treatment with non-selective NO inhibitors. Finally, the development of GN is severely aggravated in mice lacking a functional gene for eNOS as compared to wild-type mice, providing direct support for a protective role of eNOS-derived NO in acute GN.

Item does not contain fulltext Primary cutaneous posttransplantation B-cell lymphoproliferative disorder is rare. The few previously reported patients were all treated with surgery, radiotherapy, or lowering of immunosuppression. We describe a 65-year-old woman presenting with an intermammary skin ulcer 21 years after renal transplantation, proving on biopsy to be an Epstein Barr virus (EBV)-related posttransplantation B-cell lymphoproliferative disorder. A few weeks later, the skin ulcer showed complete clinical regression. Hematologic staging evaluation showed no evidence of extracutaneous involvement. Despite continuation of immunosuppression, the patient stayed free of disease until 18 months after initial diagnosis, when she developed a progressive hemiparesis and died of acute myocardial infarction. At autopsy, a recurrent B-cell posttransplantation lymphoproliferative disorder in the left side of the thalamus region (measuring 1 x 0.8 cm) was established. The long interval between the primary cutaneous lesion and the localized brain recurrence supports primary skin posttransplantation lymphoproliferative disorder, especially because the patient was not treated for her posttransplantation lymphoproliferative disorder. Review of the literature on primary cutaneous posttransplantation B-cell lymphoproliferative disorder and this case gives the impression that cutaneous posttransplantation B-cell lymphoproliferative disorders of B-cell lineage behave in a more benign manner than identical lesions arising extracutaneously. Because of the rare occurrence of posttransplantation B-cell lymphoproliferative disorder primarily involving the skin, extracutaneous origin should be excluded. If B-cell lineage can be established, EBV is present, alterations in oncogenes or tumor suppressor genes associated with malignant lymphoma are absent, and bcl-6 gene mutation associated with progression is absent, initially aggressive treatment might be avoided. However, long-term clinical follow-up with prolonged maintenance therapy (reduction of immunosuppression or antiviral therapy) for prevention of recurrent posttransplantation lymphoproliferative disorder seems indicated, as is demonstrated by the case reported in the current study.

Contains fulltext : 144559.pdf (Publisher’s version ) (Open Access) OBJECTIVE: To compare the expression of keratin (K) 13 and K19 in cutaneous warts of renal transplant recipients (RTRs) and immunocompetent individuals (ICIs). DESIGN: Retrospective, nonrandomized immunohistochemical study. PATIENTS AND METHODS: Specimens from cutaneous warts of RTRs and ICIs were retrieved from the archives of the Department of Pathology, University Medical Center St Radboud, Nijmegen, the Netherlands. Twenty-one warts from RTRs and 21 from ICIs were examined. Nine RTRs (10 specimens) received either systemic acitretin or topical all-trans retinoic acid, and their effect on both keratins was assessed. MAIN OUTCOME MEASURES: Frequency and expression patterns of K13 and K19 in warts of RTRs vs ICIs and the effect of retinoids. RESULTS: A significantly higher percentage of warts of RTRs expressed K13 compared with warts of ICIs (86% vs 14%, 18 vs 3 cases, respectively; P

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Item does not contain fulltext Primary hyperoxaluria type 1 (PH1) usually presents with recurrent urolithiasis, nephrocalcinosis and progressive renal failure at a relatively young age. This report describes a patient who, due to the late onset of end-stage renal disease, had been diagnosed with PH1 only after failure of his second kidney graft. Retrospectively, his vascular problems, skeletal abnormalities and cardiac arrhythmias fit the picture of severe systemic oxalosis. Possible therapeutic options are discussed.

Item does not contain fulltext The mechanism of expansion of the (CTG)n repeat in myotonic dystrophy (DM1) patients and the cause of its pathobiological effects are still largely unknown. Most likely, long repeats exert toxicity at the level of nuclear RNA transport or splicing. Here, we analyse cis- and trans-acting parameters that determine repeat behaviour in novel mouse models for DM1. Our mice carry 'humanized' myotonic dystrophy protein kinase (Dmpk) allele(s) with either a (CTG)84 or a (CTG)11 repeat, inserted at the correct position into the endogenous DM locus. Unlike in the human situation, the (CTG)84 repeat in the syntenic mouse environment was relatively stable during intergenerational segregation. However, somatic tissues showed substantial repeat expansions which were progressive upon aging and prominent in kidney, and in stomach and small intestine, where it was cell-type restricted. Other tissues examined showed only marginal size changes. The (CTG)11 allele was completely stable, as anticipated. Introducing the (CTG)84 allele into an Msh3-deficient background completely blocked the somatic repeat instability. In contrast, Msh6 deficiency resulted in a significant increase in the frequency of somatic expansions. Competition of Msh3 and Msh6 for binding to Msh2 in functional complexes with different DNA mismatch-recognition specificity may explain why the somatic (CTG)n expansion rate is differentially affected by ablation of Msh3 and Msh6.

Contains fulltext : 121080.pdf (Publisher’s version ) (Closed access) Alzheimer's disease (AD) brains are characterized by the presence of senile plaques (SPs), which primarily consist of amyloid beta protein (Abeta). Besides Abeta, several other proteins with the ability to modulate amyloid fibril formation accumulate in SPs, e.g. heparan sulfate proteoglycans (HSPGs). Cerebellar SPs are predominantly of the diffuse type, whereas fibrillar SPs are rarely observed. Furthermore, because of the spatial separation of non-fibrillar and fibrillar SPs in the cerebellum, this brain region provides a model for the study of the association of Abeta-associated factors with various stages of SP formation.In the present study, we performed an immunohistochemical analysis to investigate the expression of the HSPG species agrin, perlecan, glypican-1 and the syndecans 1-3 as well as glycosaminoglycan side-chains in cerebellar SPs. We demonstrated that agrin and glypican-1 were expressed in both non-fibrillar and fibrillar cerebellar SPs, whereas the syndecans were only associated with fibrillar cerebellar SPs. Perlecan expression was absent in all cerebellar SPs. Since fibrillar and non-fibrillar SPs may develop independently in the cerebellum, it is likely that agrin, glypican-1 as well as heparan sulfate glycosaminoglycans may contribute to the formation of both cerebellar plaque types, whereas syndecan only seems to play a role in the generation of cerebellar fibrillar plaques.

Item does not contain fulltext It has been suggested that the successive proteolytic events leading to the production of the amyloid-beta protein from its precursor may take place at different intracellular locations. Using cultured human leptomeningeal smooth muscle cells and brain pericytes, we modulated the intracellular localization of the amyloid-beta precursor protein (APP) to study possible effects on its processing. By using immunofluorescence and immunoelectron microscopy we demonstrated that, under normal conditions, the APP is found in small intracellular vesicles, some of which were characterized as lysosomes. Both the cytokine interferon-gamma and the lysosomotropic drug chloroquine, but not the cytokines interleukin (IL)-1, IL-6, or tumor necrosis factor-alpha (TNF-alpha), induced an accumulation of APP in newly formed multivesicular body-like organelles. The secretion of the amyloid-beta precursor protein was slightly reduced by interferon-gamma or chloroquine. Double-labeling and tracer molecule uptake experiments showed that the multivesicular body-like organelles were part of the endocytic pathway. Our findings suggest that the multivesicular body-like organelles function as an intermediate organelle in the intracellular trafficking of the APP. Accumulation of the APP in this organelle is reflected by its reduced secretion from the cell.

Item does not contain fulltext Amyloid-beta protein (A beta) deposition in the cerebral vascular walls is one of the key features of Alzheimer's disease and hereditary cerebral hemorrhage with amyloidosis-Dutch type (HCHWA-D). A beta(1-40) carrying the 'Dutch' mutation (HCHWA-D A beta(1-40)) induces pronounced degeneration of cultured human brain pericytes. In this study, we aimed to identify inhibitors of A beta-induced toxicity in human brain pericytes. The toxic effect of HCHWA-D A beta(1-40) on human brain pericytes was inhibited by co-incubation with catalase, but not with superoxide dismutase, glutathione or vitamin E analogue Trolox. Catalase interacts with A beta, both in cell cultures and in cell-free assays, and has a prominent effect on the amount and conformational state of A beta binding to the cell surface of human brain pericytes. This activity of catalase is likely based on its ability to bind and slowly degrade A beta and not by its usual capacity to convert hydrogen peroxide. Our data confirm that assembly of A beta at the cell surface of human brain pericytes is a crucial step in A beta-induced cellular degeneration of human brain pericytes. Inhibition of fibril formation at the cell surface could be an important factor in therapy aimed at reducing cerebral amyloid angiopathy.

Various pathologic conditions, such as hemorrhage, hemolysis and cell injury, are characterized by the release of large amounts of heme. Recently, it was demonstrated that heme oxygenase (HO), the heme-degrading enzyme, and heme are able to modulate adhesion molecule expression in vitro. In the present study, the effects of heme and HO on inflammation in mice were analyzed by monitoring the biodistribution of radiolabeled liposomes and leukocytes in conjunction with immunohistochemistry. Small liposomes accumulate in inflamed tissues by diffusion because of locally enhanced vascular permeability, whereas leukocytes actively migrate into inflammatory areas through specific adhesive interactions with the endothelium and chemotaxis. Exposure to heme resulted in a dramatic increase in liposome accumulation in the pancreas, but also intestines, liver, and spleen exhibited significantly increased vascular permeability. Similarly, intravenously administered heme caused an enhanced influx of radiolabeled leukocytes into these organs. Immunohistochemical analysis showed differential up-regulation of the adhesion molecules ICAM-1, P-selectin, and fibronectin in liver and pancreas in heme-treated animals. Heme-induced adhesive properties were accompanied by a massive influx of granulocytes into these inflamed tissues, suggesting an important contribution to the pathogenesis of inflammatory processes. Moreover, inhibition of HO activity exacerbated heme-induced granulocyte infiltration. Here it is demonstrated for the first time that heme induces increased vascular permeability, adhesion molecule expression, and leukocyte recruitment in vivo, whereas HO antagonizes heme-induced inflammation possibly through the down-modulation of adhesion molecules.

Item does not contain fulltext We investigated two brothers with Scheie syndrome whose only complaint was exercise intolerance. In the quadriceps muscle biopsy of both patients, between the normal muscle fibres an increased number of markedly swollen periodic acid-Schiff-positive fibroblasts were seen. Ultrastructurally, these cells showed an accumulation of enlarged lysosomes, partly filled with electro-dense material. We hypothesize that the accumulation of pathological fibroblasts may interfere with intramuscular force transmission resulting in exercise intolerance.