Neuropsychological development in children with Hurler syndrome following hematopoietic stem cell transplantation.
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Age Factors↗
Biomedical subjects
C Peters
Publications and source records attributed to C Peters.
CMV-viraemia during allogenic bone marrow transplantation in paediatric patients: association with survival and graft-versus-host disease.
Sixty-one consecutive paediatric patients undergoing allogenic bone marrow transplantation (BMT) were screened prospectively for cytomegalovirus (CMV)-viraemia by PCR. Sixteen patients (26%) presented with single or recurrent CMV-viraemia between day -7 and + 100. Although only four of them had evidence of CMV-disease, there was a significant difference in the incidence of acute Graft versus Host Disease (GVHD) grade III-IV (75% vs 15.5%), liver-involvement (68% vs 13%) and the incidence of chronic GVHD (83% vs 13.8%) between CMV-PCR-positive and CMV-PCR-negative patients. Transplant-related mortality (TRM) was 43.7% in the CMV-PCR-positive group versus 13% in patients which had no evidence for CMV-viraemia. In all but one cases mortality in CMV-PCR positive patients was GVHD-associated. Pre-emptive therapy with gancyclovir in case of CMV-viraemia seemed to have no impact on incidence and severity of GVHD.
Adolescent↗
Proposal for standard recommendations for prophylaxis of graft-versus-host disease in children. European Group for Blood and Marrow Transplantation (EBMT) Working Party Paediatric Diseases and the International Study Committee of the BFM family-subcommittee Bone Marrow Transplantation (IBFM-STG).
Great variations exist in the practices of graft-versus-host disease prophylaxis for children undergoing allogeneic stem cell transplantation. It was the aim of the EBMT Working Party on Paediatric Diseases and the International Study Group of the BFM-Family, subcommittee bone marrow transplantation (IBFM-SG) to define standard recommendation for prevention of GVHD. Thus a survey was carried out among the local representatives of the EBMT WP and IBFM-SG members to define standards for GVHD prophylaxis basing on available literature data, discussion with colleagues and their own experience. Presently the majority of regimen for GVHD prophylaxis are centred on CsA and a short course of MTX with addition of some other immunosuppression (eg ATG or ALG) in patients with high risk for severe GVHD. The proposal defined different category of patients: patients with malignant disease who are either transplanted from HLA matched sibling donors or HLA mismatched family donors (or volunteer unrelated donors) and patients with non malignant disease who might not benefit from graft-versus-leukaemia effect having either an HLA matched sibling donor or an HLA mismatched family donor (or volunteer unrelated donor). Homogeneous GVHD prophylaxis for defined patient groups should provide better information to optimise strategies in reducing treatment related toxicity and incidence of relapse by increasing GVL effect.
Adolescent↗
The present role of bone marrow and stem cell transplantation in the therapy of children with acute leukemia.
Hematopoetic stem cell transplantation (SCT) often represents a unique opportunity for curing children with leukemia. Nevertheless, selecting the patient who could really benefit from this procedure remains a controversial issue. The current consensus is as follows: About 20% of children with ALL can be defined as high-risk patients by criteria such as t(9;22), t(4;11), no complete remission at day 42, poor prednisone response, and T-immunophenotype or pre-pre B-ALL, myeloid markers or more than 100,000 white blood cells/microliter. This high-risk group is eligible for alloBMT in first remission, provided a family-matched donor is available. At relapse the majority of patients will benefit from alloBMT, and alternative donor sources can be considered in high-risk patients. Only early alloBMT relapses (up to 6 months after end of initial therapy) are sure candidates, whereas late relapses, especially extramedullary sites, may equally benefit from an intensive conventional relapse treatment. However, any alloBMT relapse beyond second remission should be transplanted with allogeneic stem cells (bone marrow or peripheral stem cells). In particular, family mismatched donors or matched unrelated donors may be acceptable in high-risk cases beyond first remission. In contrast, ASCR in ALL seems not to be superior to conventional therapy. In AML the standard-risk patient, defined by criteria such as FAB M1/M2-Auer rods positive, all FAB M3, and FAB M4, is not a candidate for SCT in first remission. Patients presenting other criteria or more than 5% of blasts in the bone marrow at day 15 are at high risk in first remission and should be considered for allo BMT if a family matched donor is available. ASCR in first remission AML remains a controversial issue. In contrast, in second remission alloBMT as well as ASCR are superior to conventional chemotherapy.
Acute Disease↗
Degradation of mouse invariant chain: roles of cathepsins S and D and the influence of major histocompatibility complex polymorphism.
Antigen-presenting cells (APC) degrade endocytosed antigens into peptides that are bound and presented to T cells by major histocompatibility complex (MHC) class II molecules. Class II molecules are delivered to endocytic compartments by the class II accessory molecule invariant chain (Ii), which itself must be eliminated to allow peptide binding. The cellular location of Ii degradation, as well as the enzymology of this event, are important in determining the sets of antigenic peptides that will bind to class II molecules. Here, we show that the cysteine protease cathepsin S acts in a concerted fashion with other cysteine and noncysteine proteases to degrade mouse Ii in a stepwise fashion. Inactivation of cysteine proteases results in incomplete degradation of Ii, but the extent to which peptide loading is blocked by such treatment varies widely among MHC class II allelic products. These observations suggest that, first, class II molecules associated with larger Ii remnants can be converted efficiently to class II-peptide complexes and, second, that most class II-associated peptides can still be generated in cells treated with inhibitors of cysteine proteases. Surprisingly, maturation of MHC class II in mice deficient in cathepsin D is unaffected, showing that this major aspartyl protease is not involved in degradation of Ii or in generation of the bulk of antigenic peptides.
Amino Acid Sequence↗
Mice deficient in lysosomal acid phosphatase develop lysosomal storage in the kidney and central nervous system.
Lysosomal acid phosphatase (LAP) is a tartrate-sensitive enzyme with ubiquitous expression. Neither the physiological substrates nor the functional significance is known. Mice with a deficiency of LAP generated by targeted disruption of the LAP gene are fertile and develop normally. Microscopic examination of various peripheral organs revealed progredient lysosomal storage in podocytes and tubular epithelial cells of the kidney, with regionally different ultrastructural appearance of the stored material. Within the central nervous system, lysosomal storage was detected to a regionally different extent in microglia, ependymal cells, and astroglia concomitant with the development of a progressive astrogliosis and microglial activation. Whereas behavioral and neuromotor analyses were unable to distinguish between control and deficient mice, approximately 7% of the deficient animals developed generalized seizures. From the age of 6 months onward, conspicuous alterations of bone structure became apparent, resulting in a kyphoscoliotic malformation of the lower thoracic vertebral column. We conclude from these findings that LAP has a unique function in only a subset of cells, where its deficiency causes the storage of a heterogeneously appearing material in lysosomes. The causal relationship of the enzyme defect to the clinical manifestations remains to be determined.
Acid Phosphatase↗
Secreted proteophosphoglycan of Leishmania mexicana amastigotes activates complement by triggering the mannan binding lectin pathway.
Cutaneous lesions induced by infection of mice with the protozoan parasite, Leishmania mexicana, contain abundant amounts of a high molecular mass proteophosphoglycan (PPG), which is secreted by the amastigote stage residing in phagolysosomes of macrophages and can then be released into the tissue upon rupture of the infected cells. Amastigote PPG forms sausage-shaped but soluble particles and belongs to a novel class of serine-rich proteins that are extensively O-glycosylated by phosphooligosaccharides capped by mannooligosaccharides. The purified molecule is shown here to efficiently activate complement (C) and deplete hemolytic activity of normal serum and may prevent the opsonization of L. mexicana amastigotes. Complement activation is Ca2+ dependent but does not depend on antibodies or the complement component C1. PPG binds to serum mannan binding protein (MBP), thus activating the MBP-associated serine protease, P100. Subsequently, the C cascade is triggered through C4 leading to covalent modification probably of carbohydrate hydroxyls of PPG by C3 fragments. Thus, PPG is able to activate C via the mannan binding lectin pathway which is unusual for secreted, soluble products of microbial origin. The proteophosphoglycan-induced complement activation is postulated to contribute to the lesion development and pathology caused by the parasite.
Animals↗
The genes of the lysosomal cysteine proteinases cathepsin B, H, L, and S map to different mouse chromosomes.
The mouse genes for the lysosomal cysteine proteinases cathepsin B, H, L, and S were mapped to Chromosomes (Chrs) 14, 9, 13, and 3, respectively. Two of the DNA probes used in this study detected an additional, independently segregating locus. The cathepsin B-specific probe hybridized to a locus on Chr 2, and the cathepsin H probe to a locus on the X Chr. These loci either correspond to pseudogenes or to cathepsin B- and cathepsin H-related genes. The four cysteine proteinases mapped in this study lie within known regions of conserved synteny between mouse and human chromosomes, when compared with the corresponding positions of their human homologs. Assuming that the genes of the cysteine proteinase gene family arose from a common ancestral gene, our results suggest that these four cysteine proteinases had been dispersed over different chromosomes before separation of mouse and human in evolution.
Animals↗
Do patients with metastatic and recurrent rhabdomyosarcoma benefit from high-dose therapy with hematopoietic rescue? Report of the German/Austrian Pediatric Bone Marrow Transplantation Group.
Patients with primary metastatic or recurrent rhabdomyosarcoma (RMS) have a very poor prognosis. Since high-dose chemotherapy (HDC) +/- TBI was thought to improve survival, many centers performed this therapy using different types of hematopoietic rescue (auto BM or PBSC, allo BM). This is a retrospective, multi-center analysis of the results of treatment in 36 patients with primary metastatic or relapsed RMS who were given HDC +/- TBI and hematopoietic rescue between 1986 and 1994. The median age was 6 years (< 1-22 years). Primary therapy was given according to either one of the Cooperative German Soft Tissue Sarcoma Studies CWS-81, -86, -91 or the European Study for Stage IV Malignant Mesenchymal Tumors in Childhood. There were 22 alveolar RMS, 13 embryonal RMS and one undifferentiated sarcoma. The indication for HDC was primary metastatic disease (27 patients) or a relapse of a primary localized tumor (nine patients). Thirty-two patients were in 1st or 2nd CR when given HDC and four in VGPR. The median time from last event to HDC was 44 weeks (21-110). HDC consisted of fractionated melphalan ((4 x 30-45 mg/m2), VP16 40-60 mg/kg, carboplatin 3 x 400-500 mg/m2) in 26 patients, 10 of whom received additional FTBI. Seven patients were treated with melphalan alone or in combination with carboplatin. Two patients received cyclophosphamide/busulphan with TLI (total lymphoid irradiation) and one cyclophosphamide with FTBI. Thirty-one patients were given autologous BM or PBSC as hematopoietic rescue and five allogeneic bone marrow from HLA-identical siblings. Fourteen patients received GM-CSF or G-CSF after hematopoietic stem cell transfusion (HSCT). Ten patients received adjuvant IL-2. There was one toxic HDC-related death. Nine patients are alive and free of disease with a median observation time of 57 months (32-108). The median time from HDC to relapse was 4 months (1-17). The tumor recurred in the majority of patients at previously known sites; in three cases new metastatic sites were observed. Patients with primary localized tumors who had been treated with HDC because of relapse did slightly better (four of nine alive with NED) than patients with primary metastatic disease (five of 27 alive with NED). HDC is still of uncertain value in the therapy of poor-risk rhabdomyosarcoma and should be performed only as part of controlled clinical trials.
Adolescent↗
Cytokines in the induction and expression of T-cell-mediated granuloma formation and protection in the murine model of listeriosis.
Lymphocyte-mediated inflammation is a hallmark of autoimmune diseases, such as multiple sclerosis. Crohn's disease, rheumatoid arthritis and sarcoidosis. However, this type of inflammation probably developed under evolutionary pressure from pathogenic microorganisms, such as mycobacteria and other intracellular infective agents. One such pathogen, the gram-positive bacterium Listeria monocytogenes (L. monocytogenes), induces a cascade of tissue alterations that ultimately results in the eradication of the bacteria associated with a granulomatous response. Consequently, murine listeriosis has been established as a model to analyze not only T-cell-dependent antibacterial protection but also T-cell-mediated mononuclear inflammation in parenchymal organs. Extensive studies of the molecular basis of the latter phenomenon led to the conclusion that the most decisive step from non-specific microabscess formation to granulomatous inflammation is the activation of non-specifically invading CD4+ T cells, which results in high local concentrations of TNF-alpha and IFN-gamma in the presence of IL-2. This in turn induces CD11b-independent mechanisms of intraparenchymal monocyte accumulation. Because any attempt to neutralize the effects of TNF-alpha and IFN-gamma to modulate T-cell-mediated inflammation will also dramatically decrease host resistance, other anti-inflammatory strategies based on the modulation of TNF-alpha and IFN-gamma-induced mechanisms of monocyte accumulation must be developed. Recalling the classical work by Dienes & Schoenheit on the induction of bacterial allergies (1), the cytokine phenotype of granuloma formation also has implications as regards the most potent adjuvant environment for the development of a T-cell response. The murine listeriosis model is the basis for all conclusions in this article on the role of cytokines in the induction and expression of T-cell-mediated inflammation and, as we will show, promises to yield still more insights into the rational design of vaccines.
Animals↗
Reconstruction of the immune system after unrelated or partially matched T-cell-depleted bone marrow transplantation in children: functional analyses of lymphocytes and correlation with immunophenotypic recovery following transplantation.
Reconstitution of the immune system following T-cell-depleted bone marrow transplantation (BMT) in children has yet to be fully elucidated. Thus, we prospectively studied the recovery of immune function in 64 children who underwent T-lymphocyte-depleted marrow transplants using either matched family member donors or matched unrelated donors. We measured in vitro posttransplantation proliferative responses to phytohemagglutinin (PHA), concanavalin A, pokeweed mitogen, and Candida albicans antigen and assessed unidirectional allogeneic mixed-lymphocyte culture (MLC) responses at various times. A total of 129 healthy individuals served as normal controls for these assays. Responses to T-cell mitogens normalized within 12 months posttransplantation, while MLC responses normalized by 9 months. The presence of graft-versus-host disease (grade II or greater) and cytomegalovirus infection was associated with delays in immune function recovery. Importantly, immune function recovery correlated temporally with a rise in peripheral lymphocyte count. In contrast, the CD4/CD8 ratio was not predictive of immune recovery. Knowledge of immune function recovery may guide clinicians in devising strategies to minimize the risk of infection post-BMT.
Adolescent↗
Proteophosphoglycan secreted by Leishmania mexicana amastigotes causes vacuole formation in macrophages.
The amastigote form of Leishmania mexicana parasites colonizes macrophage phagolysosomes and induces the enlargement of these compartments to form huge parasitophorous vacuoles. We report here that a purified secreted amastigote product, proteophosphoglycan, is a macromolecule which causes vacuolization of peritoneal macrophages in vitro. Secretion of this glycoconjugate by intracellular parasites may contribute to the expansion of phagolysosomal compartments in infected cells.
Animals↗
Allogeneic bone marrow transplantation for chronic myelomonocytic leukemia in childhood: a report from the European Working Group on Myelodysplastic Syndrome in Childhood.
PURPOSE: To evaluate the role of allogeneic bone marrow transplantation (BMT) in children with chronic myelomonocytic leukemia (CMML). PATIENTS AND METHODS: Forty-three children with CMML given BMT and reported to the European Working Group on Myelodysplastic Syndrome in Childhood (EWOG-MDS) data base were evaluated. In 25 cases, the donor was a human leukocyte antigen (HLA)-identical or a one-antigen-disparate relative, in four cases a mismatched family donor, and in 14 a matched unrelated donor (MUD). Conditioning regimens consisted of total-body irradiation (TBI) and chemotherapy in 22 patients, whereas busulfan (Bu) with other cytotoxic drugs was used in the remaining patients. RESULTS: Six of 43 patients (14%), five of whom received transplants from alternative donors, failed to engraft. There was a significant difference in the incidences of chronic graft-versus-host disease (GVHD) between children transplanted from compatible/one-antigen-mismatched relatives and from alternative donors (23% and 87%, respectively; P < .005). Probabilities of transplant-related mortality for children given BMT from HLA-identical/one-antigen-disparate relatives or from MUD/ mismatched relatives were 9% and 46%, respectively. The probability of relapse for the entire group was 58%, whereas the 5-year event-free survival (EFS) rate was 31%. The EFS rate for children given BMT from an HLA-identical sibling or one-antigen-disparate relative was 38%. In this latter group, patients who received Bu had a better EFS compared with those given TBI (62% v 11%, P < .01). CONCLUSION: Children with CMML and an HLA-compatible relative should be transplanted as early as possible. Improvement of donor selection, GVHD prophylaxis, and supportive care are needed to ameliorate results of BMT from alternative donors.
Bone Marrow Transplantation↗
[Adaptive methods in description and comparison of the distribution of biological signals].
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Electrocardiography↗
Phenotype of arylsulfatase A-deficient mice: relationship to human metachromatic leukodystrophy.
Metachromatic leukodystrophy is a lysosomal sphingolipid storage disorder caused by the deficiency of arylsulfatase A. The disease is characterized by progressive demyelination, causing various neurologic symptoms. Since no naturally occurring animal model of the disease is available, we have generated arylsulfatase A-deficient mice. Deficient animals store the sphingolipid cerebroside-3-sulfate in various neuronal and nonneuronal tissues. The storage pattern is comparable to that of affected humans, but gross defects of white matter were not observed up to the age of 2 years. A reduction of axonal cross-sectional area and an astrogliosis were observed in 1-year-old mice; activation of microglia started at 1 year and was generalized at 2 years. Purkinje cell dendrites show an altered morphology. In the acoustic ganglion numbers of neurons and myelinated fibers are severely decreased, which is accompanied by a loss of brainstem auditory-evoked potentials. Neurologic examination reveals significant impairment of neuromotor coordination.
Animals↗
Amyloidogenic processing of human amyloid precursor protein in hippocampal neurons devoid of cathepsin D.
betaA4-Amyloid peptide, the main component of the amyloid plaques in the brain of Alzheimer's disease patients is produced from amyloid precursor protein (APP) by proteolytical processing. Several lines of evidence suggest a direct role for cathepsin D, the major endosomal/lysosomal aspartic endopeptidase, in betaA4-amyloid peptide generation. Here we tested this hypothesis using primary cultures of hippocampal neurons derived from cathepsin D-deficient (knock out) mice and expressing wild-type human APP and two clinical APP variants via recombinant Semliki Forest virus. We demonstrate APP secretory processing, production of carboxyl-terminal amyloid fragments, and secretion of the betaA4-amyloid peptide in the complete absence of cathepsin D. The results rule out cathepsin D as a critical component of alpha-, beta-, or gamma-secretase and therefore as a primary target for drugs aimed at decreasing the betaA4-amyloid peptide burden in Alzheimer's disease.
Amino Acid Sequence↗
HIV infection--induced posttranslational modification of T cell signaling molecules associated with disease progression.
In attempt to elucidate the mechanism of the HIV infection induced T cell unresponsiveness, we studied signal-transducing molecules proximal to the T cell receptor (TCR) in T lymphocytes of HIV-infected individuals. Total amounts of protein tyrosine kinases (PTKs) Lck, Fyn, and ZAP-70 and the zeta chain of the TCR were found significantly decreased in T cells of symptomatic/AIDS patients as well as in T cells of individuals in acute and early asymptomatic stages of HIV infection. Unexpectedly, the detection of Lck, Fyn, and ZAP-70 was reversed after the treatment of cell lysates with dithiothreitol. This suggests that PTKs Lck, Fyn, and ZAP-70 were modified by a mechanism altering the status of sulfhydryl groups. Moreover, this mechanism seems to affect selectively T cells of HIV infected patients since B cell PTKs Syk and Lyn were detected structurally and functionally intact. Interestingly, similar alterations of signaling molecules were not detected in T cells of HIV-infected long-term asymptomatic individuals. Modification of T cell PTKs may thus underlie the HIV-induced impairment of lymphocyte function and may potentially predict disease progression.
B-Lymphocytes↗
Targeted disruption of the arylsulfatase B gene results in mice resembling the phenotype of mucopolysaccharidosis VI.
Mucopolysaccharidosis VI (MPS VI) is a lysosomal storage disease with autosomal recessive inheritance caused by a deficiency of the enzyme arylsulfatase B (ASB), which is involved in degradation of dermatan sulfate and chondroitin 4-sulfate. A MPS VI mouse model was generated by targeted disruption of the ASB gene. Homozygous mutant animals exhibit ASB enzyme deficiency and elevated urinary secretion of dermatan sulfate. They develop progressive symptoms resembling those of MPS VI in humans. Around 4 weeks of age facial dysmorphia becomes overt, long bones are shortened, and pelvic and costal abnormalities are observed. Major alterations in bone formation with perturbed cartilaginous tissues in newborns and widened, perturbed, and persisting growth plates in adult animals are seen. All major parenchymal organs show storage of glycosaminoglycans preferentially in interstitial cells and macrophages. Affected mice are fertile and mortality is not elevated up to 15 months of age. This mouse model will be a valuable tool for studying pathogenesis of MPS VI and may help to evaluate therapeutical approaches for lysosomal storage diseases.
Animals↗