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At least 649 records · Page 36Linked to original sources
PubMed1993

In vitro enhancement of erythropoiesis by steel factor in Diamond-Blackfan anemia and treatment of other congenital cytopenias with recombinant interleukin 3/granulocyte-macrophage colony stimulating factor.

Recombinant cytokines were used to investigate the pathophysiology of Diamond-Blackfan anemia (DBA) and to treat patients with Fanconi's anemia (FA) and amegakaryocytic thrombocytopenic purpura (AMT). We compared the erythroid burst forming units (BFU-E) colony growth of six DBA patients with four normal controls. BFU-E showed erythropoietin (Epo) dose dependence in all patients, although colony numbers were reduced in comparison with normals. The number and size of BFU-E were increased with the addition to Epo of interleukin 3 (IL-3) or Steel factor (SF), but IL-3 + SF was not synergistic. SF increased the nonadherent cell production in DBA long-term bone marrow cultures, and stromal cells from DBA patients showed normal SF mRNA transcripts. These data suggest that SF is not involved in the pathogenesis of DBA, although it may be useful in treatment. A small group of patients with FA and bone marrow failure were treated with daily s.c. granulocyte-macrophage colony stimulating factor (GM-CSF). Toxicity was minimal, and the majority of the patients responded with significant, sustained increase in neutrophils. Multilineage response was rare. GM-CSF may thus be palliative in patients with FA. Five patients with AMT were treated with IL-3 or IL-3 followed by GM-CSF in a phase I/II study. There was minimal toxicity, and IL-3, but not GM-CSF, resulted in improved platelet counts in two patients and decreased platelet transfusion requirements in the other three. Prolonged IL-3 treatment resulted in platelet increases in two of the latter patients. Thus, IL-3 may contribute to the treatment of patients with AMT.

Adult↗
PubMed1993

Successful treatment of Diamond-Blackfan anemia with interleukin 3.

This report describes the response of 18 Diamond-Blackfan anemia (DBA) patients to recombinant human interleukin 3 (rhIL-3). rhIL-3 was administered s.c. once daily on an escalating dose schedule (0.5-10 micrograms/kg/day). The rhIL-3 dose was escalated every 21 days until erythroid response was attained, grade III or IV nonhematologic toxicity was observed, or the maximal rhIL-3 dose was reached. Four patients experienced clinically significant erythroid responses. Two of the responders were steroid-dependent and transfusion-independent, while two were steroid-independent and transfusion-dependent. Baseline clinical or laboratory parameters, in particular in vitro bone marrow erythroid progenitor assays, were not useful in predicting rhIL-3 response. Two of the responding patients remain on maintenance rhIL-3 without diminution of effect at 490 and 855+ days. rhIL-3 was discontinued in the other two responders because of the development of deep venous thrombi.

Animals↗
PubMed1993

M-07e cell bioassay detects stromal cell production of granulocyte-macrophage colony stimulating factor and stem cell factor in normal and in Diamond-Blackfan anemia bone marrow.

Ten healthy donors and four patients with Diamond-Blackfan anemia (DBA) have been investigated for granulocyte-macrophage colony stimulating factor (GM-CSF) and stem cell factor (SCF) production by bone marrow-enriched fibroblasts (BMEF) in a highly sensitive biological assay on growth factor-dependent M-07e cells. M-07e cells detected active soluble kit-ligand from normal bone marrow fibroblasts as well as from DBA BMEF which produce constitutively significant amounts of SCF. Interleukin 1 beta (IL-1 beta) induced a significant increase of soluble SCF from both normal and DBA BMEF. GM-CSF was undetectable in unstimulated cultures, while its production by bone marrow microenvironmental cells was documented for both normal and DBA patients after IL-1 beta stimulation in vitro.

Adult↗
PubMed2000

Ribosomal protein S19 gene mutations in patients with diamond-blackfan anemia and identification of ribosomal protein S19 pseudogenes.

Diamond-Blackfan anemia (DBA) is a rare congenital pure red cell hypoplasia characterized by a selective defect of erythropoiesis with a normochromic macrocytic anemia and reticulocytopenia often accompanied by various congenital anomalies. The critical region responsible for the pathogenesis of DBA has been mapped in some patients to chromosome 19q13.2 (P Gustavsson, E Garelli, N Draptchinskaia, et al. Am. J. Hum. Genet. 63:1388-1395, 1998) and the gene encoding ribosomal protein S19 (RPS19) is believed to be the candidate gene. Here we present molecular analysis of the RPS19 gene in DBA patients from the Czech National DBA Registry. We found that the RPS19 gene was mutated in 25% (5/20) of DBA patients (insertion, deletion, and point mutations, but no nonsense or splice site mutations). Point mutations were localized to hot spots defined by Willig (TN Willig, N Draptchinskaia, I Dianzani, et al. Blood 94:4294-4306, 1999). Moreover, we describe two processed RPS19 pseudogenes, which were not expressed. Possible models of the DBA pathogenesis in the view of RPS19 mutations are discussed.

Adolescent↗
PubMed2000

Diamond-Blackfan anemia: report of seven further mutations in the RPS19 gene and evidence of mutation heterogeneity in the Italian population.

Diamond-Blackfan anemia (DBA) is a congenital disease characterized by defective erythroid progenitor maturation and physical malformations. Most cases are sporadic, but dominant or, more rarely, recessive inheritance is observed in 10% of patients. Mutations in the gene encoding ribosomal protein (RP) S19 have recently been found in 25% of patients with either the dominant or the sporadic form. DBA is the first human disease due to mutations in a ribosomal structural protein. Families unlinked to this locus have also been reported. In an investigation of 23 individuals, we identified eight different mutations in 9 patients. These include five missense, one frameshift, one splice site defect, and one 4-bp insertion in the regulatory sequence. Seven mutations are new; one has so far been found in 8 patients and is a relatively common de novo event. Two mutations are predicted to generate a truncated protein. We also report the prevalence of RPS 19 mutations in the Italian DBA population, as shown by an analysis of 56 patients. No genotype-phenotype correlation was found between patients with the same mutation. The main clinical applications for molecular analysis are clinical diagnosis of patients with an incomplete form of DBA and testing of siblings of a patient with a severe form so as to avoid using those who carry a mutation and a silent phenotype as allogeneic stem cell donors.

Adult↗
PubMed1980

Endocrine studies in Blackfan-Diamond anemia: evidence for hypothalamic-pituitary dysfunction under frequent transfusion therapy.

A 13 year old boy with Blackfan-Diamond anemia treated with frequent transfusions was investigated for endocrine abnormalities. Prepubertal plasms LH and FSH values, lack of sleep-related hormone rhythms of the gonadotropins, as well as prepubertal responses of LH and FSH to acute stimulation with LHRH strongly suggests that a hypothalamic-pituitary abnormality is the cause of the hypogonadotropic hypogonadism observed in this patient. As a result of impaired stimulation of the gonads plasm testosterone was prepubertal. A three-to fourfold increase of basal plasma PRL values was found without any signs of a typical sleep-dependent increase. Values obtained ranged between 21 ng/ml and 24 ng/ml (normal range 5-8 ng/ml). A normal response to TRH stimulation was found. These results suggest that hemosiderosis may be responsible for the hyperprolactinemia as a result of hypothalamic-pituitary dysfunction. Furthermore, dysfunction is demonstrated by prepubertal responses of LH and FSH to LHRH stimulation.

Adolescent↗
PubMed1996

Allogeneic bone marrow transplatation in a patient with Shwachman-Diamond syndrome.

Shwachman-Diamond syndrome (SDS) is a rare inherited disorder involving concomitant neutropenia and exocrine pancreatic insufficiency. About 25% of patients develop hematopoietic malignancies. We describe a 24-year-old male patient with SDS who underwent allogeneic bone marrow transplantation (BMT) because of progression into acute myeloid leukemia (AML) following myelodysplastic syndrome (MDS). The BMT preparative regimen consisted of busulfan (16 mg/kg body wt.), followed by cyclophosphamide (120 mg/kg). Cyclosporin A and short methotrexate were used for graft-versus-host disease (GvHD) prophylaxis. The post-transplant period was complicated by staphylococcal septicemia, CMV infection, renal insufficiency, and acute GvHD grade III. Hematological recovery was delayed (post-transplant day +55). The patient was discharged at day +68 in complete remission without any evidence of MDS. RFLP fingerprint analysis showed complete engraftment of the donor's hematopoiesis. The patient's leukemia relapsed 9 months post-transplant, and death followed due to CMV infection and multiorgan failure. Despite the fatal course in this patient, allogeneic BMT could be an option for curative treatment of the hematopoietic failure in SDS. The interaction of BMT with pancreatic insufficiency still has to be ascertained.

Adult↗
PubMed1993

Diamond Blackfan anaemia: apparent relapse due to B19 parvovirus.

A spontaneous remission occurred after 3 years of regular transfusions in a cortico resistant Diamond Blackfan anaemia. However after 1 year of transfusion independence an apparent relapse was observed which was transient and could be attributed to a B19 parvovirus primary infection. Previous inapparent impairment of erythropoiesis can be transiently spotlighted by B19 parvovirus primary infection.

Antibodies, Viral↗
PubMed1990

Intravenous immunoglobulin in Diamond-Blackfan anaemia.

Since immunological disorders have been demonstrated in patients with Diamond-Blackfan anaemia (DBA), intravenous immunoglobulins (IVIG) were administered to a 14-year-old girl with DBA and congenital malformations, previously treated with corticosteroids and blood transfusions. No therapeutic effect was observed.

Adolescent↗
PubMed1995

Shwachman-Diamond syndrome: clinical, radiological and sonographic aspects.

Six children with Shwachman-Diamond syndrome have been diagnosed and treated in our hospital since 1986. We describe the radiological and sonographic findings of this rare disease which is characterized by metaphyseal chondrodysplasia, neutropenia and pancreatic exocrine insufficiency. It presents with variable extremity shortening, "cup" deformation of the ribs, metaphyseal widening and hypoplasia of the iliac bones, and increased echogenicity of the pancreas without change in size. We discuss the differential diagnosis and review the literature.

Bone Marrow↗
PubMed1995

Shwachman-Diamond syndrome: clinical, radiological and sonographic findings.

Six children with Shwachman-Diamond syndrome have been diagnosed and treated in our hospital since 1986. We describe the radiological and sonographic findings of this rare disease, which is characterized by metaphyseal chondrodysplasia, neutropenia and exocrine pancreatic insufficiency. It presents with varying extremity shortening, "cup" deformation of the ribs, metaphyseal widening and hypoplasia of the iliac bones, as well as increased echogenicity of the normalized pancreas. We discuss the differential diagnosis and review the literature.

Bone Marrow Diseases↗
PubMed2000

[Press-fit bone dowel arthrodesis of the ankle or the subtalar joint using a diamond bone cutting system. Surgical technique and initial results in 10 patients].

Arthrodesis of the ankle (AA) or the subtalar joint (AST) is still a necessary treatment in case of painful posttraumatic arthrosis or paresis of the muscles after compartment syndrome. Today the alloplastic ankle joint replacement does not satisfy. Many treatments of arthrodesis with minimal or extended resection of the joint surface with or without bone transplantation are described in literature. We present in detail a new developed technique of press-fit dowel arthrodesis (KDA) for the ankle and subtalar joint. After adjustment of the joint position and retention with Kirschner wires the surface of both sides of the joint surface and underlying bone is removed by a cannulated diamond bone cutting device. Dowels from the anterior iliac crest are impacted in the cutted joint defect. The dowels are 1/10 mm bigger in dimension than the primary defect in the joint surface. The surgery will be completed with a compression screw osteosynthesis, at the ankle joint transarticular through the lateral and medial malleolus, at the subtalar joint from plantar. Ten patients have treated by press-fit-KDA (female 2, male 8; AA 7, 33.6 +/- 9 y; AST 3.38 +/- 10.9 y). The indication for KDA was in nine cases a severe posttraumatic arthrosis, in one case the paretic malfunction after compartment syndrome. The arthrodesis were clinically and radiologically consolidated after 8.2 +/- 1.9 weeks. At this time the patients showed no symptoms and were fully mobilised with complete weight-bearing. The advantages of KDA: preservation of the outline of joint and hindfoot, preservation of length of the leg and outline of iliac crest, no risk for the soft tissue, quick consolidation of the arthrodesis, no need of external fixation. The technique is also suitable for other indications as presented.

Adult↗
PubMed2002

TOF-SIMS and XPS-investigations of ion implanted single crystal 1b-diamonds.

Near surface zones of (48)Ti- and (52)Cr-implanted single crystal diamonds (1b-MCD) were characterized by XPS, TOF-SIMS and white light interference microscopy (WLI). By the combination of WLI and TOF-SIMS it was possible to calibrate the depth scale of TOF-SIMS and XPS depth profiles quantitatively. The adjustment of TOF-SIMS and XPS elemental depth profiles in the implantation maximum increases the quantitative detection limit of the implanted elements by more than two orders of magnitude and enables the interpretation of results from wear simulation experiments. Peak fits of XPS C(1s)-photolines indicate the fraction and chemical nature of carbide-like structures in the implantation zone. Qualitative hints on carbide compounds are possibly included in the reconstructed TOF-SIMS spectra but this information can presently only be extracted with the aid of XPS analyses.

Journal Article↗
PubMed1995

Electrochemical characterization of boron-doped polycrystalline diamond thin-film electrodes.

The electrochemical characterization of boron-doped polycrystalline diamond thin-film (BDF) electrodes was studied using the anodic scan after concentrating lead in 0.1 mol/L KCl - 41 micromol/L Hg(NO(3))(2) and 0.1 mol/L KNO(3) - 0.01 mol/L HNO(3) - 41 micromol/L Hg(NO(3))(2); accumulation voltage was -0.90 V. The results obtained were compared with those given by glassy carbon (GC) electrodes and proved that the BDF electrodes offered high sensitivity, good precision and extreme stability over a 2-month period. These electrodes provided good resolving power for the determination of lead and cadmium and gave satisfactory results in the analysis of a pure water sample.

Journal Article↗
PubMed2004

Novel SBDS mutations caused by gene conversion in Japanese patients with Shwachman-Diamond syndrome.

Shwachman-Diamond syndrome (SDS; OMIM 260400) is an autosomal recessive disorder characterized by exocrine pancreatic insufficiency, bone marrow dysfunction and metaphyseal chondrodysplasia. SDS is caused by mutations in SBDS, an uncharacterized gene. A previous study in SDS patients largely of European ancestry found that most SBDS mutations occurred within a approximately 240-bp region of exon 2 and resulted from gene conversion due to recombination with a pseudogene, SBDSP. It is unknown, however, whether these findings are applicable to other ethnic groups. To address this question, we examined SBDS mutations in six Japanese families with SDS by direct sequencing. We identified compound heterozygous mutations in four families: two were recurrent (96-97insA, 258+2T>C), and three were novel [292-295delAAAG, (183-184TA>CT +201A>G), (141C>T+183-184TA>CT+201A>G)] mutations. Most of these mutations also appear to result from gene conversion, but the conversion events occurred at various sites between intron 1 and exon 3. Thus, gene conversion mutations in SBDS are common to different ethnic groups, but they are not confined to a limited region of the gene.

Alleles↗
PubMed1999

Truncating ribosomal protein S19 mutations and variable clinical expression in Diamond-Blackfan anemia.

Diamond-Blackfan anemia (DBA) is a rare constitutional erythroblastopenia characterized by a specific defect in erythroid differentiation. Recently, mutations in the gene encoding ribosomal protein (RP) S19 were found in a subset of patients with the disease. To characterize further RPS19 mutations and to investigate genotype-phenotype relationships, we screened this gene for mutations in patients with DBA by direct sequencing and Southern-blot analysis. Four novel mutations were identified. A G120A nonsense mutation resulting in a stop at codon 33, a C302T nonsense mutation introducing a premature stop at codon 84, and a 327delG which results in a frame shift at codon 103. A fourth and more complex mutation (TT157-158AA, 160insCT) resulting in a Leu45Gln and a frame shift from codon 47 was found in three affected family members with variable phenotypes. The different clinical expression for identical mutations suggest the presence of other modulating factors for the disease. The mutations presented here further support the role of RPS19 in erythropoietic differentiation and proliferation.

Adult↗
PubMed2005

Effects of food supplementation on the physiological ecology of female Western diamond-backed rattlesnakes (Crotalus atrox).

Food availability is an important factor in the life histories of organisms because it is often limiting and thus can affect growth, mass change, reproduction, and behaviors such as thermoregulation, locomotion, and mating. Experimental studies in natural settings allow researchers to examine the effects of food on these parameters while animals are free to behave naturally. The wide variation among organisms in energy demands and among environmental food resources suggest that responses to changes in food availability may vary among organisms. Since most supplemental feeding field experiments have been conducted on species with high energy demands, we conducted a supplemental feeding study on free-ranging, female Western diamond-backed rattlesnakes (Crotalus atrox), a species with low energy demands and infrequent reproductive investment. Snakes were offered thawed rodents 1-4 times per week. Over two active seasons, we collected data on surface activity, home range size, growth, mass change, and reproduction of supplementally fed and control snakes. Fed and control snakes did not differ in surface activity levels (proportion of time encountered above versus below ground) or home range size. Fed snakes grew and gained mass faster, and had a dramatically higher occurrence of reproduction than control snakes. Also, fed snakes were in better body condition following reproduction than snakes that were not fed. However, litter characteristics such as offspring number and size were not increased by feeding, suggesting that these characteristics may be fixed. These data experimentally demonstrate that food availability can directly impact some life history traits (i.e., growth and reproduction for C. atrox), but not others (i.e., surface activity and home range size for C. atrox). The relationship between food availability and life history traits is affected in a complex way by ecological traits and physiological constraints, and thus interspecific variation in this relationship is likely to be high.

Analysis of Variance↗