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PubMed1976

Abnormal tryptopham metabolism in congenital erythroid hypoplastic (Diamond-Blackfan) anaemia.

Tryptophan loading was performed in a child with Diamond-Blackfan anaemia as well as in his parents and two control persons. There was a fivefold increase of anthranilic acid and kynurenine excretion beside a marked generalized aminoaciduria in the proband; in the parents and the controls no such phenomenon could be demonstrated. The importance of the finding is discussed and investigation of tryptophan metabolism before the first blood transfusion is recommended. The finding cannot be used as a heterozygote test.

Anemia, Aplastic↗
PubMed1999

The ultraflex esophageal and diamond biliary stents.

This article begins with an overview of the history and development of stents. The material properties unique to the Ultraflex esophageal stent and the Diamond biliary stent along with their clinical benefits are presented in detail. The author also provides detailed product information, recommendations, and contraindications for the use of both stents.

Alloys↗
PubMed1999

The ultraflex diamond stent for benign biliary obstruction.

The most frequent type of benign bile duct stricture (BBDS) that complicates surgery, is not an indication for placement of any current model of metal stent because of poor long-term results. This statement could not apply to less frequent types of BBDSs, in particular those complicating chronic pancreatitis (CP) and radiotherapy. The authors report their preliminary results observed in 10 patients whose CP-related BBDS was treated with an Ultraflex Diamond stent. No stent dysfunction was detected in the observed patients during a mean follow-up of 17 months. Studies involving larger numbers of patients followed for longer periods of time are necessary to know whether endoscopy using this material may replace surgery in this indication.

Bile Duct Diseases↗
PubMed1999

Shwachman-Diamond syndrome: An inherited preleukemic bone marrow failure disorder with aberrant hematopoietic progenitors and faulty marrow microenvironment.

Shwachman-Diamond syndrome (SD), an inherited disorder with varying cytopenias and a marked tendency for malignant myeloid transformation, is an important model for understanding genetic determinants in hematopoiesis. To define the basis for the faulty hematopoietic function, 13 patients with SD (2 of whom had myelodysplasia with a clonal cytogenetic abnormality) and 11 healthy marrow donors were studied. Patients with SD had significantly lower numbers of CD34(+) cells on bone marrow aspirates. SD CD34(+) cells plated directly in standard clonogenic assays showed markedly impaired colony production potential, underscoring an intrinsically aberrant progenitor population. To assess marrow stromal function, long-term marrow stromal cell cultures (LTCs) were established. Normal marrow CD34(+) cells were plated over either SD stroma (N/SD) or normal stroma (N/N); SD CD34(+) cells were plated over either SD stroma (SD/SD) or normal stroma (SD/N). Nonadherent cells harvested weekly from N/SD LTCs were strikingly reduced compared with N/N LTCs; numbers of granulocyte-monocyte colony-forming units (CFU-GM) derived from N/SD nonadherent cells were also lower. SD/N showed improved production of nonadherent cells and CFU-GM colonies compared with SD/SD, but much less than N/N. Stem-cell and stromal properties from the 2 patients with SD and myelodysplasia did not differ discernibly from SD patients without myelodysplasia. We conclude that in addition to a stem-cell defect, patients with SD have also a serious, generalized marrow dysfunction with an abnormal bone marrow stroma in terms of its ability to support and maintain hematopoiesis. This dual defect exists in SD with and without myelodysplasia.

Adolescent↗
PubMed1999

Mutations in ribosomal protein S19 gene and diamond blackfan anemia: wide variations in phenotypic expression.

Mutations of the ribosomal protein S19 (RPS19) gene were recently identified in 10 patients with Diamond Blackfan anemia (DBA). To determine the prevalence of mutations in this gene in DBA and to begin to define the molecular basis for the observed variable clinical phenotype of this disorder, the genomic sequence of the 6 exons and the 5' untranslated region of the RPS19 gene was directly assessed in DBA index cases from 172 new families. Mutations affecting the coding sequence of RPS19 or splice sites were found in 34 cases (19.7%), whereas mutations in noncoding regions were found in 8 patients (4.6%). Mutations included nonsense, missense, splice sites, and frameshift mutations. A hot spot for missense mutations was identified between codons 52 and 62 of the RPS19 gene in a new sequence consensus motif W-[YFW]-[YF]-x-R-[AT]-A-[SA]-x-[AL]-R-[HRK]-[ILV]-Y. No correlation between the nature of mutations and the different patterns of clinical expression, including age at presentation, presence of malformations, and therapeutic outcome, could be documented. Moreover, RPS19 mutations were also found in some first-degree relatives presenting only with isolated high erythrocyte adenosine deaminase activity and/or macrocytosis. The lack of a consistent relationship between the nature of the mutations and the clinical phenotype implies that yet unidentified factors modulate the phenotypic expression of the primary genetic defect in families with RPS19 mutations.

Adolescent↗
PubMed2001

[An investigation of the bio-tribological performance of diamond-like carbon/ultrahigh molecular weight polyethylene couple].

OBJECTIVE: To evaluate the friction property of diamond-like carbon (DLC) film/Ti6Al4V gradient material sliding against UHMWPE couple. METHOD: Tests of this couple were made under dry sliding and lubrication of Hank's solution and 0.9% NaCl solution respectively, and they were compared with the friction property of Ti6Al4V sliding against UHMWPE couple. The tests were performed on an SRV friction and wear tester by means of surface-contact and coefficients of friction were recorded real-time. RESULT: DLC film could reduce the friction coefficient evidently. The coefficients of friction reduced 24%, 5.0%, 10% than these of Ti6Al4V under dry sliding and lubrication of Hank's solution and 0.9% NaCl solution respectively. Mechanism of friction was also studied by observing scanning electrical microscopy (SEM) morphology of frictional surfaces. CONCLUSION: Friction-reduction mechanism of DLC film/Ti6Al4V could be resulted from amorphous structure of DLC film which was smooth and hard.

Biocompatible Materials↗
PubMed2000

Susceptibility of diamond back moth, Plutella xylostella (L) to entomopathogenic nematodes.

Eight entomopathogenic nematode species / strains, Steinernema glaseri (steiner), S. carpocapsae (Weiser), S. feltiae (Filipjev), Steinernema sp. Ecomax strain, Heterorhabditis bacteriophora (Pioner), Heterorhabditis sp. Ecomax strain, two locally isolated strains called as JFC and TFC were tested against the final instar larvae of diamond back moth, Plutella xylostella (L.). All nematodes were found pathogenic. However, H. bacteriophora was adjudged the most pathogenic amongst the test nematodes on the basis of LD50 (9.16 IJS/larva), LT50 (43.26 hr), Lex T50 (3.24 hr) and the propagation potential (average of 271.42 IJS/mg) on the host body weight.

Animals↗
PubMed2003

Electrochemical oxidation of phenolic and other organic compounds at boron doped diamond electrodes for wastewater treatment: effect of mass transfer.

The paper presents the results of an experimental study on oxidation at boron doped diamond electrodes (BDD) of some phenolic compounds: phenol (PH), para-hydroxibenzoic acid (PHB), cathecole (CT), hydroquinone (HQ) are considered, singularly contained in aqueous solutions or in the presence of glucose (G), which was selected to represent the class of biodegradable compounds. Oxidation of benzoquinone (BQ) and maleic acid (MA), generally detected as intermediates products from phenol degradation, is also investigated. Great attention is paid to verify the feasibility of a selective process in which the oxidation is specifically addressed to the phenolic fraction up to non toxic intermediate products which are more biodegradable than the original phenols.

Biodegradation, Environmental↗
PubMed1991

In vitro growth and regulation of bone marrow enriched CD34+ hematopoietic progenitors in Diamond-Blackfan anemia.

Diamond-Blackfan anemia (DBA) is a congenital red blood cell aplasia. No clear explanation has been given of its defective erythropoiesis, although different humoral or cellular inhibitory factors have been proposed. To clarify the nature of this defect we studied the effect of several human recombinant growth factors on an enriched CD34+ population obtained from the bone marrow of 10 DBA patients. We observed a defect underlying the early erythroid progenitors, which were unresponsive to several growth factors (erythropoietin, interleukin-3 [IL-3], IL-6, granulocyte-macrophage colony-stimulating factor [GM-CSF], erythroid potentiating activity), either alone or in association. The production of cytokines was not impaired, and high levels of IL-3 and GM-CSF were found in phytohemagglutinin-leukocyte-conditioned medium (PHA-LCM) when tested with a sensitive biologic assay on the M-07E cell line. Hematopoietic stem cells in DBA patients may be induced to differentiate to the granulocyte megakaryocyte, but not the erythroid compartment, as shown after CD34+ cell preincubation with IL-3. Addition of the stem cell factor to IL-3 and erythropoietin induces a dramatic in vitro increase in both the number and the size of BFU-E, which also display a normal morphologic terminal differentiation.

Antigens, CD↗
PubMed1990

[Functional state of the body and morbidity among diamond cutters].

The article contains results of the studies of the visual analyzer, cardio-vascular system and central nervous system, as well as prevalence and structure of morbidity with temporary disability among the major professions in diamond processing. It was established that resulting from a complex of labour factors (hypodynamics, forced posture at work, overstrain of the sight, monotony) the working capacity was falling down in the shift dynamics, fatiguability was rapidly developing with concomitant decline in health state indices, thus necessitating the introduction of preventive measures.

Asthenopia↗
PubMedDate not supplied

Cryptosporidium sp. infection in the proventriculus of an Australian diamond firetail finch (Staganoplura bella: Passeriformes, Estrildidae).

An Australian diamond firetail finch died following the acute onset and development of severe diarrhea. The bird was purchased from a wholesaler and was housed in a pet store aviary with 12 other birds. Necropsy, histologic evaluation, and electron microscopic evaluation revealed organisms in the proventriculus (surface, ductal, and glandular epithelium) compatible in site of development, size, and morphology with Cryptosporidium spp. Lesions in the proventriculus were focal cuboidal metaplasia of glandular epithelial cells and deposition of amyloid in the perivascular interstitial tissues at the base of the glands. Amyloid also was present in the duodenum, liver, spleen, pancreas, and kidney. Inability to recover other organisms suggested that Cryptosporidium was the primary cause of diarrhea and death. The affected bird likely suffered dehydration as a result of acute gastrointestinal disturbance, concomitant with renal amyloidosis and urate nephrosis.

Animals↗
PubMed1990

[Gardner-Diamond syndrome].

This paper presents a 26-year-old woman with the characteristic features of Gardner-Diamond syndrome: recurrent painful bruises reproducible by intradermal injection of autologous red blood cells, and a "hysterical" personality pattern together with nonspecific multisystem complaints.

Adult↗
PubMed1990

Scanning electron microscopy of corneal incisions using steel, diamond, and sapphire blades.

In order to compare the wound morphology they produce, we used steel (Myocure), diamond (CILCO DK 121), and sapphire (Katena K2-6500) blades, to make parallel linear incisions, 500 microns deep, in 12 fresh enucleated porcine eyes. There was no discernible difference among the blades in terms of either the morphology of the collagen lamellae of the sides or the depth of the incisions produced. The major differences in the cuts produced were attributable primarily to the differences in the footplates.

Animals↗
PubMed1989

Auto-erythrocyte sensitisation--the Gardner-Diamond syndrome. A case report.

A 34-year-old woman with a 3-year history of easy bruising of unexplained aetiology in anatomical sites consistent with self-infliction is described. Despite major surgery, the patient had never experienced inappropriate bleeding. Owing to psychological instability, the possibility of auto-erythrocyte sensitisation was considered; this was confirmed by subcutaneous injection of autologous red cells and haemolysate, which caused local tenderness and induration. This manifestation of Gardner-Diamond syndrome is unusual and is reported to draw attention to its existence and perhaps thereby avoid unnecessary and costly investigations.

Adult↗
PubMed1989

Diamond-blackfan anemia: etiology, pathophysiology, and treatment.

Diamond-Blackfan anemia (DBA) is manifested by a wide variety of clinical and in vitro abnormalities. Despite this biological diversity, the hematological phenotype is remarkably similar for all patients and consists of a normochromic-macrocytic anemia in early childhood, reticulocytopenia, and a normocellular marrow with a selective deficiency of red cell precursors. Fetal hemoglobin is usually increased, distributed heterogeneously, has a fetal G gamma/A gamma pattern, and is associated with increased expression of red cell i antigen. Although most cases are sporadic, there are examples of autosomal recessive and autosomal dominant inheritance patterns. Approximately 70% of patients with DBA respond to prednisone, and many can be maintained on tapered doses. Those who are steroid-dependent at high dosage as well as those who do not respond are managed on a transfusion and iron chelation program. Claims of efficacy for other therapies, such as cyclosporine or high-dose intravenous methylprednisolone, require substantiation. Bone marrow transplantation has been successfully performed in patients who have tissue-matched donors, and the procedure cures the anemia. Recombinant growth factors may be a therapy of the future. Regarding pathophysiology, initial reports of humoral or cellular inhibitors of erythropoiesis were not confirmed in all laboratories. However, some patients have lymphocyte dysfunction with decreased T cells, decreased T4/T8 ratios, and defective lymphocyte-mediated suppression of lymphoproliferation. A large body of data indicates that the erythroid stem cells are intrinsically defective in DBA, and they are partly or completely refractory to erythropoietin. The role of elevated red cell adenosine deaminase activity in the pathogenesis of this abnormal erythropoiesis is not clear, but this finding is characteristic of the syndrome in most patients. Present studies using recombinant growth factors have demonstrated a diversity of defects in erythropoiesis in patients with DBA. Blocks in red cell production and red cell maturation were seen at various levels along the differentiation pathway. Of clinical interest, interleukin-3 has a corrective effect in vitro on the aberrant marrow erythropoiesis of steroid-refractory patients, and, hence, it may have therapeutic application.

Adrenal Cortex Hormones↗
PubMed1987

Focal pontine leukoencephalopathy in a patient with the Shwachman-Diamond syndrome.

A 35-year-old woman who died after a long history of an illness consistent with Shwachman-Diamond Syndrome, was found to have extensive calcified necrotizing lesions confined to the pontocerebellar fibers of the basis pontis. The possible relationship of this recently described lesion to the patient's immunosuppressed state and/or other systemic metabolic disturbances is discussed.

Adult↗