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Biomedical subjects

C Peters

Publications and source records attributed to C Peters.

At least 55 records · Page 3Linked to original sources
PubMed2001

Allogeneic bone marrow transplantation-mediated transfer of specific immunity against Toxocara canis associated with excessive IgE.

A girl with myelodysplastic syndrome (RAEB-T) received HLA-identical bone marrow from her younger brother after myeloablative treatment with busulfan and cyclophosphamide. After bone marrow transplantation, fever, exanthema, pruritus, and a pulmonary infiltrate were treated symptomatically. Bacterial cultures remained negative. Leukocyte engraftment began on day 10, and all blood cell populations proved to be of donor origin on FISH analysis. Increasing IgE levels (21 000 U/ml) on day 14 after BMT, positive RAST, specific IgG-antibodies, and missing Toxocara (T.) canis antigens in the recipient indicated donor-derived seroconversion. Before BMT, the recipient had been negative for T. canis in routine parasitological screening, and the donor proved to be positive for T. canis antibody by ELISA. This report suggests that the transfer of IgE immunity in the absence of detectable antigens may be responsible for IgE-mediated symptoms consistent with toxocara infection and confirms the need for parasite screening in donor medical examinations.

Adoptive Transfer↗
PubMed2001

Influence of transplantation regimen on prognostic significance of high-level minimal residual disease before allogeneic stem cell transplantation in children with ALL.

High MRD levels before transplantation in children receiving T cell-depleted unrelated grafts for relapsed ALL were associated with a 100% relapse risk. We report on two children with relapsed ALL who underwent non T cell-depleted BMT from unrelated donors. Despite a high residual tumor load pre- transplant and the occurrence of only aGVHD grade I, they are still in second complete remission 2.7 and 5.2 years after transplantation, respectively. Thus, we propose that the transplant regimens influence the prognostic significance of high MRD levels pre-BMT.

Burkitt Lymphoma↗
PubMed2001

A multi-institutional analysis of laparoscopic orchidopexy.

OBJECTIVE: To combine and analyse the results from centres with a large experience of laparoscopy for the impalpable testis with small series, to determine the expected success rate for laparoscopic orchidopexy. METHODS: A questionnaire was distributed to participating paediatric urologists; each contributor retrospectively reviewed the clinical charts for their cases of therapeutic laparoscopy for an impalpable testis, detailing 36 variables for each patient. The data were collated centrally into a computerized database. For inclusion, the testis was intra-abdominal (including 'peeping' at the internal ring) at laparoscopic examination, was not managed through an open approach and did not undergo orchidectomy. Three surgical groups were assessed, with success defined as lack of atrophy and intrascrotal position: group 1, primary laparoscopic orchidopexy; group 2, a one-stage Fowler-Stephens (F-S) orchidopexy; and group 3, a two-stage F-S orchidopexy. RESULTS: Data were gathered from 10 centres in the USA, covering the period 1990-1999; 252 patients representing 310 testes were included and overall, 15.2% were lost to follow-up. There was no significant difference between success rates in the larger and smaller series. Atrophy occurred in 2.2% of 178 testes, 22.2% of 27 testes and 10.3% of 58 testes in groups 1-3, respectively. Testes were not in a satisfactory scrotal position in 0.6%, 7.4% and 1.7% of groups 1-3, respectively. The mean follow-up for each group was 7.7, 8.6 and 20.0 months, respectively. The overall success for all groups was 92.8% (97.2% group 1; 74.1% group 2; 87.9% group 3), with an atrophy rate of 6.1%. CONCLUSION: Laparoscopic orchidopexy for the intra-abdominal testis, in both large and small series, can be expected to have a success rate higher than that historically ascribed to open orchidopexy. Within this series, single-stage F-S laparoscopic orchidopexy resulted in a significantly higher atrophy rate than the two-stage repair. However, when considering both F-S approaches, the laparoscopic approach gave greater success than previously reported for the same open approaches. Despite the weaknesses inherent in a retrospective unrandomized study, we conclude that laparoscopic orchidopexy is, if not the procedure of choice, an acceptable and successful approach to the impalpable undescended testicle.

Child, Preschool↗
PubMed2001

Serial granulocytapheresisunder daily administration of rHuG-CSF: effects on peripheral blood counts, collection efficiency, and yield.

BACKGROUND: An option for treatment of severe infections in neutropenic patients is the transfusion of granulocytes from donors stimulated with rHuG-CSF. The schedule of rHuG-CSF-stimulated granulocyte donations and the quality of the components remain controversial. This study was done with the intention of ensuring daily granulocyte support with therapeutic cell numbers, while keeping the patients' allogeneic exposure as low as possible. STUDY DESIGN AND METHODS: Granulocyte collection with multiple consecutive leukapheresis procedures under daily rHuG-CSF administration and with hydroxyethyl starch as sedimenting agent were prospectively studied. Complete blood counts of the donors, collection yield, and efficiency were analyzed. RESULTS: Products (n = 259) from 76 donors were examined. The median peripheral blood WBC and neutrophil counts were 28.1 g per L and 24.1 g per L, respectively, and they were significantly higher on Day 5 of collections than on Days 1 to 3. Platelet counts and Hb levels decreased steadily. Collection yields increased over time from 4.9 to 6.7 x 10(10) neutrophils. Side effects of cytokines and aphereses did not exceed World Health Organization grade II status. CONCLUSION: Repetitive daily rHuG-CSF administration-even under daily leukapheresis procedures-results in a continuing increase in WBC and neutrophil levels and thus leads to increased collection yields. Side effects are tolerable, although Hb and platelet levels should be monitored closely.

Adolescent↗
PubMed2001

Towards specific functions of lysosomal cysteine peptidases: phenotypes of mice deficient for cathepsin B or cathepsin L.

The lysosomal cysteine peptidases cathepsin B and cathepsin L are abundant and ubiquitously expressed members of the papain family, and both enzymes contribute to the terminal degradation of proteins in the lysosome. However, there is accumulating evidence for specific functions of lysosomal proteases in health and disease. The generation of 'knock out' mouse strains that are deficient in lysosomal proteases provides a valuable tool for evaluation of existing hypotheses and gaining new insights into the in vivo functions of these proteases. In this minireview, we summarise and discuss the findings obtained by analysis of mice that are devoid of cathepsin B or cathepsin L. In brief, cathepsin L appears to be critically involved in epidermal homeostasis, regulation of the hair cycle, and MHC class II-mediated antigen presentation in cortical epithelial cells of the thymus. Cathepsin B plays a major role in pathological trypsinogen activation in the early course of experimental pancreatitis and contributes significantly to TNF-alpha induced hepatocyte apoptosis.

Animals↗
PubMed2001

The chemical biology of Ras lipidation.

In this review, we summarize the successful interplay between three disciplines, organic synthesis, biophysics and cell biology, in the study of protein lipidation and its relevance to targeting of proteins to the plasma membrane of cells in molecular detail. Highlighting the example of the Ras proteins, we show how the development of new synthetic methodologies paved the road to the synthesis of lipidated peptides and--by a combination of chemical and molecular biological techniques--lipidated proteins as molecular tools. We further give an overview of the results of the biophysical properties and biological activities of the molecules synthesized by means of this interdisciplinary approach. This successful combination of different disciplines led to a better understanding of the selective targeting of Ras and related lipoproteins to the plasma membrane.

Animals↗
PubMed2000

Imidovanadium(v) complexes as reaction partners for kinetically stabilized phosphaalkynes: synthesis of 1,2,4-azaphosphavanada(v)-cyclobutenes, 1,3,5-triphosphabenzenes, and 1H-1,2,4-azadiphospholes.

Cycloaddition reactions of the kinetically stabilized phosphaalkynes 1 with the imidovanadium(v) trihalides 9 furnish the 1,2,4-azaphosphavanada(v)cyclobutenes 10. The stability of these novel metallacyclic compounds depends solely on the substitutents of the imido unit. Thus, the imidovanadium(v) species 9 with tertiary alkyl groups on the N atom form stable addition products with 1 while in the cases of compounds 9 with a lower degree of substitution at N (primary and secondary alkyl groups) the primarily formed adducts 10 undergo irreversible decomposition to afford the 1H-1,2,4-azadiphospholes 13. Reactions of an excess of the phosphaaalkyne 1 with the vanadium complexes 9 furnish the corresponding triphosphabenzenes 8 in good yields (36-68%). A catalytic reaction course has been demonstrated for the all-tert-butyl system 1a/9a in which the metallacyclic species 10a serves as the catalytically active species. Poisoning of the catalyst leads to a second reaction pathway, which results in formation of the azatetraphosphaquadricyclanes 16. By means of the stepwise use of different phosphaalkynes 1a,b this methodology provides the first access to the differently substituted triphosphabenzenes through cyclotrimerization.

Journal Article↗
PubMed2000

Successful stem cell transplantation following orthotopic liver transplantation from the same haploidentical family donor in a girl with hemophagocytic lymphohistiocytosis.

The case of a 4-month-old girl with familial hemophagocytic lymphohistiocytosis is described. The patient underwent stem cell transplantation from her haploidentical mother 2 months after receiving a living-related liver transplant from the same donor for acute hepatic failure. Conditioning regimen consisted of 16 mg/kg busulfan, 200 mg/kg cyclophosphamide, 10 mg/kg thiothepa, and antithymocyte globulin. Myeloid engraftment occurred on day +10, but CD3(+) cells of recipient origin remained. To convert the T-cell chimerism, the patient received donor lymphocyte infusion on day +43, and subsequently the allelic pattern changed to complete donor genotype on day +57. Four months after stem cell transplantation the patient is disease free, with complete donor chimerism in bone marrow and stable hepatic graft function without any immunosuppressive therapy. (Blood. 2000;96:3997-3999)

Behavior Therapy↗
PubMed2000

Cathepsin D deficiency induces lysosomal storage with ceroid lipofuscin in mouse CNS neurons.

Cathepsin D-deficient (CD-/-) mice have been shown to manifest seizures and become blind near the terminal stage [approximately postnatal day (P) 26]. We therefore examined the morphological, immunocytochemical, and biochemical features of CNS tissues of these mice. By electron microscopy, autophagosome/autolysosome-like bodies containing part of the cytoplasm, granular osmiophilic deposits, and fingerprint profiles were demonstrated in the neuronal perikarya of CD-/- mouse brains after P20. Autophagosomes and granular osmiophilic deposits were detected in neurons at P0 but were few in number, whereas they increased in the neuronal perikarya within days after birth. Some large-sized neurons having autophagosome/autolysosome-like bodies in the perikarya appeared in the CNS tissues, especially in the thalamic region and the cerebral cortex, at P17. These lysosomal bodies occupied the perikarya of almost all neurons in CD-/- mouse brains obtained from P23 until the terminal stage. Because these neurons exhibited autofluorescence, it was considered that ceroid lipofuscin may accumulate in lysosomal structures of CD-/- neurons. Subunit c of mitochondrial ATP synthase was found to accumulate in the lysosomes of neurons, although the activity of tripeptidyl peptidase-I significantly increased in the brain. Moreover, neurons near the terminal stage were often shrunken and possessed irregular nuclei through which small dense chromatin masses were scattered. These results suggest that the CNS neurons in CD-/- mice show a new form of lysosomal accumulation disease with a phenotype resembling neuronal ceroid lipofuscinosis.

Action Potentials↗
PubMed2000

Long-term effect of bone-marrow transplantation for childhood-onset cerebral X-linked adrenoleukodystrophy.

BACKGROUND: The childhood-onset cerebral form of X-linked adrenoleukodystrophy, a demyelinating disorder of the central nervous system, leads to a vegetative state and death within 3-5 years once clinical symptoms are detectable. The hypothesis to be tested was whether bone-marrow transplantation can over an extended period of time halt the inexorable progressive demyelination and neurological deterioration. METHODS: 12 patients with childhood onset of cerebral X-linked adrenoleukodystrophy have been followed for 5-10 years after bone-marrow transplantation. Magnetic resonance imaging (MRI), neurological, neuropsychological, electrophysiological, and plasma very-long-chain fatty acid (VLCFA) measurements were used to evaluate the effect of this treatment. FINDINGS: MRI showed complete reversal of abnormalities in two patients and improvement in one. One patient showed no change from baseline to last follow-up. All eight patients who showed an initial period of continued demyelination stabilised and remained unchanged thereafter. Motor function remained normal or improved after bone-marrow transplantation in ten patients. Verbal intelligence remained within the normal range for 11 patients. Performance (non-verbal) abilities were improved or were stable in seven patients. Decline in performance abilities followed by stability occurred in five patients. Plasma VLCFA concentrations decreased by 55% and remained slightly above the upper limits of normal. INTERPRETATION: 5-10-year follow-up of 12 patients with childhood-onset cerebral X-linked adrenoleukodystrophy shows the long-term beneficial effect of bone marrow transplantation when the procedure is done at an early stage of the disease.

Adrenoleukodystrophy↗
PubMed2000

Mouse cathepsin F: cDNA cloning, genomic organization and chromosomal assignment of the gene.

A murine cysteine protease of the papain family was identified by dbEST-database search. A 1.87kb full-length cDNA encoding a predicted polypeptide of 462 amino acids was sequenced. Since the encoded polypeptide shows more than 80% sequence identity with human cathepsin F, it is most likely that this cDNA represents the murine homologue of cathepsin F, and it was therefore named accordingly. Murine cathepsin F exhibits a domain structure typical for papain-like cysteine proteases, a 20 amino acid N-terminal hydrophobic signal sequence followed by an extraordinarily long propeptide of 228 amino acids and the domain of the mature protease comprising 214 amino acids. The mature region contains all features characteristic of a papain-like cysteine protease, including the highly conserved cysteine, histidine and asparagine residues of the 'catalytic triad'. Genomic clones covering the murine cathepsin F gene were isolated. The mouse cathepsin F gene consists of 14 exons and 13 introns and spans 5.8kb. Murine cathepsin F was mapped to chromosome 19, a region with synteny homology to a region of human chromosome 11 to which human cathepsin F has been mapped previously. Northern blot analysis of RNA from multiple tissues revealed a ubiquitous expression of cathepsin F in mouse and man.

Amino Acid Sequence↗
PubMed2000

Murine and human cathepsin Z: cDNA-cloning, characterization of the genes and chromosomal localization.

A novel murine cysteine protease from the family of papain-like cysteine proteinases was identified by dbEST-database search. A 1. 4-kb full-length cDNA encoding a predicted polypeptide of 306 amino acids was characterized. The new protease, tentatively named cathepsin Z, exhibits all features characteristics of a papain-like cysteine protease, including the highly conserved residues of the 'catalytic triad'. Cathepsin Z shares only 26-35% overall homology with previously described mammalian papain-like cysteine peptidases and has an unusually short propeptide, which may indicate that it is a member of a putative new subfamily within the family of papain-like cysteine peptidases. Genomic clones covering the murine and human cathepsin Z genes were isolated. They comprise six exons and five introns spanning a 12-kb region of genomic DNA, respectively. Murine cathepsin Z was mapped to chromosome 2, a region with synteny homology to a region of human chromosome 20 to which human cathepsin Z has been mapped previously. Northern blot analysis revealed ubiquitous expression of murine cathepsin Z. Multiple transcriptional start sites were identified for the murine cathepsin Z gene and together with the absence of a TATA box, a high G+C content, a CpG island and the presence of several Sp1-binding sites in the promoter region, murine cathepsin Z may be classified as a 'housekeeping' gene.

Amino Acid Sequence↗
PubMed2000

Ceramide as an activator lipid of cathepsin D.

We have identified the aspartic protease cathepsin D as a novel intracellular target protein for the lipid second messenger ceramide. Ceramide specifically binds to and induces CTSD proteolytic activity. A-SMase deficient cells derived from Niemann-Pick patients show decreased CTSD activity that was reconstituted by transfection with A-SMase cDNA. Ceramide accumulation in cells derived from A-ceramidase defective Farber patients correlates with enhanced CTSD activity. These findings suggest that A-SMase-derived ceramide targets endolysosomal CTSD.

Amidohydrolases↗
PubMed2000

Observing proteases in living cells.

The lysosomal cysteine protease cathepsin B has been implicated in tumor progression and metastasis in part due to its altered trafficking. In order to analyze the trafficking of cathepsin B in living cells, we utilized enhanced green fluorescent protein (EGFP) fused to various cathepsin B constructs for transfecting two cell lines: an invasive human breast adenocarcinoma cell line (BT20) and a cathepsin B deficient mouse embryonic fibroblast cell line (MEF T -/-). The cells were transiently transfected with four cathepsin B-EGFP fusion constructs: full-length preprocathepsin B-EGFP, cathepsin B preregion-EGFP, cathepsin B prepro region-EGFP, and cathepsin B prepro region-EGFP with a mutation of the glycosylation site in the pro region. The full length construct showed vesicular distribution throughout the cells in both cell lines. In both BT20 and MEF T -/- cells, preregion-EGFP was localized in a ring tightly associated with the cell nucleus, suggesting distribution to the endoplasmic reticulum. The distribution of the prepro region-EGFP construct was similar except that it also included some patchy areas adjacent to the nucleus. This suggested that the cathepsin B prepro region-EGFP might have entered the Golgi. Distribution of the mutated cathepsin B prepro region-EGFP was similar to that of wild-type prepro region-EGFP in the MEF T -/-. In the invasive BT20 cells, however, the mutated prepro region-EGFP showed a vesicular distribution throughout the cytoplasm and in cell processes. This distribution is similar to that of endogenous cathepsin B in these cells. Our results suggest that: 1) tumor cells have an alternative mechanism for trafficking of cathepsin B which is independent of the mannose-6-phosphate receptor pathway, and 2) the pro region of cathepsin B may contain the sorting sequence necessary for its trafficking via this pathway.

Adenocarcinoma↗
PubMed2000

Correction of odontoid dysplasia following bone-marrow transplantation and engraftment (in Hurler syndrome MPS 1H).

BACKGROUND: Odontoid dysplasia is recognized as a major component of the constellation of dysostosis multiplex lesions associated with Hurler's syndrome (MPS 1H). Because of this abnormality, there is an increased risk of atlantoaxial subluxation with potential cervical spinal cord injury. A significant alteration of the natural history of the disease with respect to the visceral, cardiac, and skeletal systems has resulted in an increased life span for MPS 1H patients associated with engraftment from normal donors. OBJECTIVE: The purpose of this study was to evaluate the longitudinal changes of odontoid dysplasia in MPS 1H following engraftment from bone-marrow transplantation (BMT). MATERIALS AND METHODS: A retrospective review of sequential plain film or cervical spine MR was performed in patients with MPS 1H. Odontoid morphology was graded as aplasia, severe dysplasia, moderate dysplasia, mild dysplasia, or normal. Odontoid morphology was plotted against the time interval. Fully engrafted, nontransplanted, and partially engrafted patients had careful imaging evaluation of the odontoid process. RESULTS: Ten patients were studied with a mean interval follow-up of 8.7 years post-BMT. Seven patients were totally engrafted. Two patients were nontransplanted, and one patient had only partial engraftment (20% enzyme activity). All totally engrafted patients had a progressive improvement in the grade of odontoid dysplasia following BMT. Patients with partial engraftment or without transplantation demonstrated static or increasing odontoid dysplasia. MR imaging showed abnormal dural soft-tissue masses at the level of C2 in all patients. Reduction in the grade of odontoid dysplasia was not associated with significant change in the appearance of the upper cervical soft-tissue masses. CONCLUSION: For the first time, this report documents that patients with MPS 1H show a decrease in the degree of odontoid dysplasia on imaging after successful engraftment following BMT.

Bone Diseases, Developmental↗
PubMed2000

[Therapeutic concept in combined orthodontic-surgical treatment of class II malocclusion with short face syndrome. New aspects for surgical lengthening of the lower face].

The main aesthetic concern of patients with Angle class II deformities with skeletal deep bite--short face syndrome--is the short lower face. It is the orthodontist's task to correct this deformity insofar as possible. Depending on the extent, even orthodontists at the beginning of their training will recognize this. Since presurgical orthodontic treatment determines the kind and extent of the surgical procedure, the orthodontist has to plan the treatment in for individual case. It is the purpose of this article to demonstrate a concept of treatment for patients with class II deformities, skeletal deep bite, and a short lower face. Presurgical orthodontic treatment and the surgical procedure to correct the deformity are discussed. The treatment results show that it is necessary to leave or to create a certain curve of Speed, depending on the extent of the deformity, to achieve a satisfactory result in terms of to function, aesthetics, and stability. It can be concluded that it is only possible to reach the preset treatment goals with an exact diagnosis and the knowledge of the necessary preparation in combination with the surgical procedure.

Adult↗