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C Peters

Publications and source records attributed to C Peters.

At least 199 records · Page 11Linked to original sources
PubMed1993

Oligonucleotide DNA fingerprinting: results of a multi-center study on reliability and validity.

We report the results of an empirical study of 256 paternity cases referred to 7 different German laboratories for DNA fingerprinting with oligonucleotide probe (CAC)5/(GTG)5. All parameters characteristic of such multilocus DNA fingerprints were found to differ significantly between the contributing centres. Despite these differences, clear-cut decisions between paternity and non-paternity could be made in all but one case. Furthermore, we found no systematic deviation of the gel-phenotype distribution among trios from random expectation as derived from commonly adopted analytical models. Thus, we conclude that oligonucleotide DNA fingerprinting is a robust and reliable means for the resolution of paternity cases.

Base Sequence↗
PubMed1993

Paternity testing with oligonucleotide multilocus probe (CAC)5/(GTG)5: a multicenter study.

The statistical analysis is reported of 256 paternity cases referred to seven different German laboratories for multilocus DNA fingerprinting with oligonucleotide probe (CAC)5/(GTG)5 and restriction enzyme HinfI. All parameters characteristic of multilocus DNA fingerprints were found to differ significantly between the contributing centres: the number of analyzed gel positions, the number of bands scored per individual, the probability of occurrence of a band at a particular position, and the band-sharing probabilities between the mother and both child and alleged father. Despite these differences, paternity cases could be divided clearly into two distinct subgroups on the basis of (i) offspring bands that could not be assigned to either the mother or the alleged father and (ii) the extent of band-sharing between child and alleged father. This partitioning, which is likely to correspond to true and false paternity, confirms previous findings for other multilocus probes. A goodness-of-fit test on the normalized number of bands scored per individual revealed no systematic deviations from commonly adopted analytical models regarding electrophoretic bands as independent entities. Log10-likelihood ratios of paternity vs. non-paternity were calculated utilizing one of these models, and a clear-cut partitioning was again obtained which coincides with that mentioned before. Only one case could not be decided unambiguously, and was either due to two independent mutations or to a close relative of the alleged father being the true father.

Child↗
PubMed1993

Myeloablative radiochemotherapy and hematopoietic stem-cell rescue in poor-prognosis Ewing's sarcoma.

PURPOSE: The prognosis of patients with multifocal primary and early or multiple relapsed Ewing's sarcoma is poor with conventional chemoradiotherapy and surgery. We evaluated the efficacy and feasibility of a myeloablative regimen administered as consolidation treatment for these patients. PATIENTS AND METHODS: The ablative regimens consisted of simultaneous radiochemotherapy: 12 Gy hyperfractionated total-body irradiation (TBI; two doses of 1.5 Gy for 4 days) plus fractionated high-dose melphalan (30 to 45 mg/m2 for 4 days) followed by high-dose etoposide (40 to 60 mg/kg) with or without carboplatin (900 to 1,500 mg/m2) (hyper-ME +/- C). These regimens were applied in a dose-escalation study that included 17 patients. All patients underwent remission induction chemotherapy and local treatment before myeloablative therapy. Seven patients had multifocal primary Ewing's sarcoma, and 10 had early or multiple relapse. We performed a matched-cohort analysis of the 17 grafted patients with 41 historic controls matched for sex, age, diagnosis, extent of disease, interval from diagnosis to transplant in the transplant group, and interval from diagnosis to relapse in the control group. RESULTS: The probability of relapse in the study patients is 52% at 6 years after the last event before transplantation. In the control group, the probability of relapse at 6 years was 98%. Eight of 17 treated patients are alive in complete remission at a median observation time of 49 months (range, 19 to 76) from the last event before transplantation. Probability of relapse-free survival in the study patients is 45% +/- 12% at 6 years after the last event before transplant, compared with 2% +/- 2% for the historic control group. CONCLUSION: Myeloblative therapy with hyper-ME +/- C radiochemotherapy can improve the prognosis of multifocal primary and early or multiple relapsing Ewing's sarcoma.

Adolescent↗
PubMed1993

Structure of the human arylsulfatase B gene.

We have isolated lambda-phage clones containing the human arylsulfatase B gene region from a genomic lambda 47.1 library. The human arylsulfatase B gene comprises 8 exons interrupted by 7 introns. DNA sequences of all intron-exon boundaries and the 5' flanking region of the gene were determined. All intron-exon splice junctions conformed to the GT/AG consensus sequence. Primer extension analysis revealed multiple start sites 1 to 135 nucleotides 5' of the ATG translational start codon. A 398 bp DNA-fragment of the 5' flanking region exhibits promotor activity when transiently expressed in BHK-21 cells using the bacterial chloramphenicol acetyltransferase gene as a reporter gene. This putative promotor region is located in a CpG island and contains potential Sp1 and AP2 binding sites but lacks typical TATA and CAAT box motifs.

Bacteriophage lambda↗
PubMed1993

[Collection and long-term preservation of peripheral stem cells].

The methods of collection and storage of peripheral blood stem cells are described and the harvesting after conditioning with cytokines and/or myelosuppressive therapy is discussed. It could be demonstrated that the combination of cytostatics and cytokines gives the best yield and enables to collect a sufficient amount of peripheral blood stem cells for a successful engraftment after myeloablative therapy with only few aphereses.

Antigens, CD↗
PubMed1992

Phylogenetic conservation of cysteine proteinases. Cloning and expression of a cDNA coding for human cathepsin S.

A 1.8-kilobase full-length cDNA of human cathepsin S, a lysosomal cysteine proteinase, has been isolated. The single long open reading frame encodes a polypeptide of 331 amino acids consisting of a 15-amino acid NH2-terminal signal peptide, a propeptide of 99 amino acids, and a mature polypeptide of 217 amino acids. The deduced amino acid sequence contains only one potential N-glycosylation site located in the propeptide. The NH2-terminal amino acid sequence of the mature polypeptide was confirmed by sequencing cathepsin S purified from human spleen. The cDNA detects a 1.9-kilobase transcript in poly(A)+ RNA from human fibroblasts. Expression of human cathepsin S in transfected baby hamster kidney cells resulted in up to more than 300-fold cathepsin S activity as compared to untransfected controls. In the expressing baby hamster kidney cells, human cathepsin S is transported to the lysosomes via the mannose 6-phosphate receptor pathway as shown by density gradient centrifugation, immunofluorescence, and detection of the 37-kDa cathepsin S precursor in the medium in the presence of NH4Cl. The deduced amino acid sequence of human cathepsin S exhibits a substantial degree of similarity with other human cysteine proteinases and papain indicating that they have a common ancestral gene and are members of a gene family.

Amino Acid Sequence↗
PubMed1992

Correction of human mucopolysaccharidosis type-VI fibroblasts with recombinant N-acetylgalactosamine-4-sulphatase.

A full-length human N-acetylgalactosamine-4-sulphatase (4-sulphatase) cDNA clone was constructed and expressed in CHO-DK1 cells under the transcriptional control of the Rous sarcoma virus long terminal repeat. A clonal cell line expressing high activities of human 4-sulphatase was isolated. The maturation and processing of the human enzyme in this transfected CHO cell line showed it to be identical with that seen in normal human skin fibroblasts. The high-uptake precursor form of the recombinant enzyme was purified from the medium of the transfected cells treated with NH4Cl and was shown to be efficiently endocytosed by control fibroblasts and by fibroblasts from a mucopolysaccharidosis type-VI (MPS VI) patient. Enzyme uptake was inhibitable by mannose 6-phosphate. After uptake, the enzyme was processed normally in both normal and MPS VI fibroblasts and was shown both to correct the enzymic defect and to initiate degradation of [35S]sulphated dermatan sulphate in MPS VI fibroblasts. The stabilities of the recombinant enzyme and enzyme from human fibroblasts appeared to be similar after uptake. However, endocytosed enzyme has a significantly shorter half-life than endogenous human enzyme. The purified precursor 4-sulphatase had a similar pH optimum and catalytic parameters to the mature form of 4-sulphatase isolated from human liver.

Alkaline Phosphatase↗
PubMed1992

An N-acetylgalactosamine-4-sulfatase mutation (delta G238) results in a severe Maroteaux-Lamy phenotype.

Maroteaux-Lamy syndrome (mucopolysaccharidosis type VI, MPS VI) is an autosomally inherited lysosomal storage disorder caused by a deficiency of N-acetylgalactosamine-4-sulfatase (EC 3.1.6.1; 4-sulfatase). In order to determine the gene defect in a clinically severe MPS VI patient, polymerase chain reaction (PCR) products were generated from the patient's fibroblast mRNA and also from a 4-sulfatase cDNA clone and subjected to the chemical cleavage technique to detect mismatched bases, which were then identified by direct DNA sequencing of the PCR products. The patient was homozygous for an early frameshift mutation caused by the deletion of a G at position 238 (delta G238), which produces a truncated 4-sulfatase with an altered amino acid sequence from amino acid 80 to a premature stop codon at codon 113 relative to the normal 4-sulfatase reading frame of 533 amino acids. Since the mutation occurs only 40 amino acids past the signal peptidase cleavage site, it is most likely that this will result in a protein with no 4-sulfatase activity. This is consistent with the severe clinical presentation and the absence of 4-sulfatase enzyme activity or mutant 4-sulfatase protein in the patient. The patient was also found to be homozygous for two polymorphisms, i.e., a G to A transition at nucleotide 1072 resulting in a valine358 to methionine substitution (V358M) and a salient A to G transition in the third base of the proline397 codon at nucleotide 1191.

Amino Acid Sequence↗
PubMed1992

The internalization signal in the cytoplasmic tail of lysosomal acid phosphatase consists of the hexapeptide PGYRHV.

Lysosomal acid phosphatase (LAP) is rapidly internalized from the cell surface due to a tyrosine-containing internalization signal in its 19 amino acid cytoplasmic tail. Measuring the internalization of a series of LAP cytoplasmic tail truncation and substitution mutants revealed that the N-terminal 12 amino acids of the cytoplasmic tail are sufficient for rapid endocytosis and that the hexapeptide 411-PGYRHV-416 is the tyrosine-containing internalization signal. Truncation and substitution mutants of amino acid residues following Val416 can prevent internalization even though these residues do not belong to the internalization signal. It was shown recently that part of the LAP cytoplasmic tail peptide corresponding to 410-PPGY-413 forms a well-ordered beta turn structure in solution. Two-dimensional NMR spectroscopy of two modified LAP tail peptides, in which the single tyrosine was substituted either by phenylalanine or by alanine, revealed that the tendency to form a beta turn is reduced by 25% in the phenylalanine-containing peptide and by approximately 50% in the alanine-containing mutant peptide. Our results suggest, that in the short cytoplasmic tail of LAP tyrosine is required for stabilization of the right turn and that the aromatic ring system of the tyrosine residue is a contact point to the putative cytoplasmic receptor.

Acid Phosphatase↗
PubMed1992

Pharmacokinetics and pharmacodynamics of erythropoietin during therapy in an infant with renal failure.

We treated an infant with anemia and chronic renal failure with recombinant human erythropoietin (300 to 750 U/kg subcutaneously per week) and iron (6 mg/kg enterally) from 1 to 4 months of age. A suboptimal pharmacodynamic response was seen at the lower dose. This may have been due to developmental erythropoietin pharmacokinetic differences, that is, relatively greater neonatal plasma clearance and steady-state volume of distribution compared with those in adults.

Anemia↗
PubMed1992

Variations in practice among urologists and nephrologists treating children with vesicoureteral reflux.

To analyze the current management recommendations among physicians treating children with vesicoureteral reflux, the American Urological Association Reflux Practice Guidelines Panel surveyed 100 pediatric urologists, 100 general urologists and 100 pediatric nephrologists by questionnaire, and received a 60% response. In the evaluation of a 4-year-old girl with bilateral grade 2 reflux general urologists were more likely than the other 2 groups to recommend cystoscopy and urethral dilation. At followup nuclear cystography was recommended by 76% of pediatric urologists, 48% of general urologists and 71% of pediatric nephrologists, while the latter 2 groups were less likely to recommend any subsequent upper tract evaluation. Pediatric urologists were significantly more likely to recommend antireflux surgery if the child had 1 breakthrough febrile urinary tract infection, poor compliance with medical management or persistent reflux at age 11 years. In a 6-year-old girl with unilateral grade 4 reflux and detrusor instability 44% of pediatric urologists recommended antimicrobial prophylaxis and anticholinergic therapy compared to 12% of general urologists and 6% of pediatric nephrologists. Antireflux surgery was recommended by 29% of pediatric urologists, 60% of general urologists and 59% of pediatric nephrologists. In older girls with persistent grade 2 or 3 reflux pediatric urologists were much more likely to recommend antireflux surgery. In contrast, they were less likely to recommend surgery in young girls and boys with newly diagnosed grade 4 reflux. These data demonstrate significant differences in therapeutic recommendations among pediatric urologists, general urologists and pediatric nephrologists, and suggest the need for outcomes research to determine the optimal management of children with vesicoureteral reflux.

Child↗
PubMed1992

Protective immunity and granuloma formation are mediated by two distinct tumor necrosis factor alpha- and gamma interferon-dependent T cell-phagocyte interactions in murine listeriosis: dissociation on the basis of phagocyte adhesion mechanisms.

Listeria-immune mice are able to express protective immunity in the absence of CD4+ T cells and an apparent granulomatous inflammation. Using a monoclonal antibody (5C6) able to inhibit the recruitment of myelomonocytic cells into inflammatory foci by binding to complement receptor type 3 (CR3/CD11b), we could show that protective immunity and granuloma formation indeed depend on two distinct types of T cell-phagocyte interactions. Listeria-specific CD8+ T lymphocytes, possibly in collaboration with CD4- CD8- T cells, rapidly interact with myelomonocytic cells infiltrating infected tissues in a CR3/CD11b-dependent manner. This interaction results in potent antilisterial protection but not in granuloma formation. On the contrary, CD4+ T cells are able to induce adhesion mechanisms that allow the accumulation of monocytes in granulomatous lesions even in the presence of monoclonal antibody 5C6. However, the protective capacity of these CR3/CD11b-independent T cell-mediated immune mechanisms is low in listeriosis. Tumor necrosis factor alpha and gamma interferon, known to be essential for the expression of both resistance and acquired immunity, are shown to be necessarily involved in granuloma formation, too. It therefore remains to be explained why CD8+ T cells, able to secrete both cytokines, do not induce granuloma formation. The data point to the presence of an as yet undefined CD4+ T cell-derived granuloma-inducing factor and favor the hypothesis that CD8+ T cells, in collaboration with circulating phagocytes, mediate immunity by rapidly liberating listeriae from permissive cells or protecting them from becoming infected.

Animals↗
PubMed1992

Lysosomal acid phosphatase is not involved in the dephosphorylation of mannose 6-phosphate containing lysosomal proteins.

The mannose 6-phosphate (Man6P) residues that are necessary for the targeting of newly synthesized lysosomal proteins are dephosphorylated after delivery of lysosomal proteins to lysosomes. To examine the role of lysosomal acid phosphatase (LAP) for the dephosphorylation of Man6P residues in lysosomal proteins, the phosphorylation of endogenous lysosomal proteins and of internalized arylsulfatase A was analyzed in mouse L-cells that overexpress human LAP. Non-transfected L-cells dephosphorylate endogenous lysosomal proteins slowly (half time approximately 13 h) as well as internalized arylsulfatase A. A more than 100-fold overexpression of LAP in these cells did not affect the dephosphorylation rate. Control experiments showed that the internalized arylsulfatase A and overexpressed LAP partially colocalize and that under in vitro conditions purified LAP does not dephosphorylate arylsulfatase A. Taken together, these results indicate that LAP is not the mannose 6-phosphatase that dephosphorylates lysosomal proteins after their delivery to lysosomes.

Acid Phosphatase↗
PubMed1992

Lysosomal acid phosphatase is internalized via clathrin-coated pits.

The presence of lysosomal acid phosphatase (LAP) in coated pits at the plasma membrane was investigated by immunocytochemistry in thymidine kinase negative mouse L-cells (Ltk-) and baby hamster kidney (BHK) cells overexpressing human LAP (Ltk-LAP and BHK-LAP cells). Double immunogold labeling showed that at various stages of invaginating coated pits LAP colocalized with clathrin and plasma membrane adaptors (HA-2 adaptors). Quantitation of the immunogold label showed similar density of wild-type LAP in coated over non-coated areas of the plasma membrane, whereas an internalization-deficient, truncated mutant of LAP which lacks the cytoplasmic tail was less efficiently included into coated pits. Internalization of anti-LAP antibodies into endosomal vesicles was accompanied by rapid dissociation of the coat proteins as shown by an immunofluorescence assay. The role of clathrin-coated vesicles in internalization of LAP was further corroborated by microinjecting monoclonal antibodies against clathrin or HA-2 adaptors into BHK-LAP cells. Internalization of LAP as detected by an immunofluorescence assay was transiently blocked by microinjected antibodies against clathrin or HA-2 adaptors, whereas unrelated antibodies did not affect internalization. These data suggest that LAP is included into clathrin-coated pits of the plasma membrane for rapid internalization.

Acid Phosphatase↗
PubMed1992

Treatment of infant leukemia with busulfan, cyclophosphamide +/- etoposide and bone marrow transplantation.

Infants with acute leukemia have a poor chance of being cured by conventional chemotherapy. We therefore treated cases of infant leukemia with high dose chemotherapy followed by bone marrow transplantation (BMT). Six suffered from acute leukemia and one from refractory anemia with excess of blasts (RAEB-t). The conditioning regimen consisted of busulfan (BU) and cyclophosphamide (CY), and was intensified by adding etoposide (VP) in four cases. At the time of BMT the children were 4, 5, 12, 13, 13, 14, and 20 months old. Three children were autografted, three received HLA-identical marrow from a sibling donor, and one child received matched unrelated donor marrow. All five children who were grafted in complete (CR) or partial remission (PR) are alive and well in CR 7, 13, 24, 37, and 46 months after allogeneic (two patients) or autologous (three patients) BMT, and 13, 17, 29, 42, and 53 months after initial diagnosis. The child with RAEB-t and the one transplanted in second chemotherapy-resistant relapse of acute non-lymphoblastic leukemia relapsed at 7 and 17 months respectively. The chemotherapy regimen was well tolerated. BU-CY-VP is a promising alternative treatment to regimens including total body irradiation for very young children suffering from acute leukemia.

Bone Marrow Transplantation↗
PubMed1991

The essential tyrosine of the internalization signal in lysosomal acid phosphatase is part of a beta turn.

For rapid endocytosis lysosomal acid phosphatase requires a Tyr-containing signal in its cytoplasmic domain, as do cell surface receptors mediating endocytosis and clustering in coated pits. To determine the structure of the internalization signal an 18 amino acid peptide representing the cytoplasmic tail of lysosomal acid phosphatase was analyzed by two-dimensional nuclear magnetic resonance spectroscopy. Part of the peptide, 5-PPGY-8, forms a well-ordered beta turn of type I in solution. Our result and data on the structure of the endocytosis signal of the low density lipoprotein receptor reported by Bansal and Gierasch in the accompanying paper represent experimental determinations of the three-dimensional structure of protein transport signals and suggest that the essential aromatic amino acid of internalization signals is recognized by a putative cytoplasmic receptor in the structural context of a tight turn.

Acid Phosphatase↗
PubMed1991

Restoration of arylsulphatase A activity in human-metachromatic-leucodystrophy fibroblasts via retroviral-vector-mediated gene transfer.

Metachromatic leukodystrophy is a lysosomal storage disease caused by the deficiency of arylsulphatase A (ASA). A human ASA cDNA was subcloned into the retroviral vector pXT1. Replication-defective retrovirus was generated by transfection of the vector into the amphotropic packaging cell line PA317. Human fibroblasts from a patient suffering from metachromatic leucodystrophy was infected with the recombinant retrovirus. Infected fibroblasts expressed ten times more ASA compared with control fibroblasts from a normal individual. The ASA encoded by the integrated provirus was shown to be correctly transported into the lysosomes and to normalize the impaired degradation of cerebroside sulphate.

Cell Fractionation↗