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PubMedDate not supplied

Expression of CD5 on hematogones in a 7-year-old girl with Shwachman-Diamond syndrome.

We report increased numbers of hematogones in a 7-year-old girl with pancytopenia due to Shwachman-Diamond syndrome. Her hematogones expressed the T-cell marker CD5 as well as CD19, CD10, and CD20, and terminal deoxynucleotidyl transferase and HLA-DR. These findings suggest that hematogones are precursors of both CD5-positive B cells and CD5-negative B cells. Thus CD5-positive B cells in bone marrow may be derived from bone marrow stem cells, and not from the residual fetal B cells of yolk sac/liver origin. The finding of CD5 expression on hematogones also raises the possibility that neoplastic B cells of chronic lymphocytic leukemia, which characteristically co-express CD5 and CD19, may be derived from CD5-positive B-cell precursors in bone marrow and not from mature B cells in lymph nodes.

B-Lymphocytes↗
PubMed1976

Hepatocellular carcinoma, transfusion-induced hemochromatosis and congenital hypoplastic anemia (Blackfan-Diamond syndrome).

A 25 year old patient with congenital hypoplastic anemia (Black-fan-Diamond syndrome) is described. This patient was hepatitis-antigen negative, had not received androgens and had a hepatoma develop in a transfusional hemochromatotic liver. Since androgens have been associated with hepatocellular carcinoma, the use of androgenic steroids for other than life-threatening symptoms in this disease should be avoided.

Adult↗
PubMed1981

Diamond-coated all-purpose foreign-body forceps.

A new foreign-body forceps with diamond-coated jaws can grasp and hold intraocular foreign bodies of any shape and composition. A self-closing mechanism holds the material once grasped.

Eye Foreign Bodies↗
PubMed1979

The grinding efficiency of diamond burs.

Deterioration of round diamond burs during 8 minutes of operation was found to be more pronounced for burs with low particle densities than for burs with high particle density. No definitive relationship was found between the initial grinding rate and initial particle density.

Dental Enamel↗
PubMed1980

Axenic growth of Giardia lamblia in Diamond's TPS-1 medium.

A strain of Giardia lamblia was gradually adapted to grow in Diamond's TPS-1 medium. The parasites grew luxuriantly and formed a monolayer on the surface of the culture vessels. When G. lamblia was inoculated into fresh medium, the population of the parasites grew from 22,000 cells/ml to peak numbers of 2.1 X 10(6)/ml in six days with a generation time of 12.2 hours at 37 degrees C. After a few days of incubation a sediment could be seen at the bottom of the tubes which contained a multitude of free-swimming Giardia as well as clumps of them. The sediment sometimes also contained many rings of Giardia. The rings were usually associated with dead Giardia cells containing a large bubble. Two, three and sometimes as many as six Giardia were seen surrounding the bubble. The bubble probably provides additional surface area to which the Giardia may attach.

Animals↗
PubMedDate not supplied

A modification of Diamond's medium for the axenic culture of Entamoeba histolytica.

The use of casein hydrolysate in Diamond's axenic culture medium TPS-1 in replacement of trypticase allowed good growth of the trophozoites of Entamoeba histolytica. This modified medium also supported growth of trophozoites preserved for 16 months in liquid nitrogen. Considerable labour and cost of serum can be saved by using 5% instead of 10% bovine serum in combination with this modified medium.

Animals↗
PubMed1994

Cobalt excretion in urine: results of a study on workers producing diamond grinding tools and on a control group.

A study was carried out on cobalt (Co) excretion in the urine of 12 workers exposed to known cobalt concentrations in the stone cutting diamond wheel production and in six volunteers: four of these were exposed in the same work environment for a whole workshift and the other two were exposed to cobalt in a cabin under experimental conditions. The kinetics of the urinary excretion was multiphase: (i) a first stage of rapid elimination (T 1/2' = 43.9 h); (ii) a second phase of slower elimination (T 1/2'' = 10 days); (iii) a longer period of retention, of the order of years, in subjects with higher exposure. In the control group (4 subjects), the excretion proved to be much faster in the first stage (T 1/2' = 20 h). The different behaviour of the two groups could be related to the different body burden, of cobalt and/or to the possibility of different kinetics induced by continuous exposure to the metal. Moreover, 3 weeks after the removal of the workers from exposure the urinary cobalt concentrations were not within the normal limits of CoU for the general population, (even for workers exposed to cobalt levels of the same order as the TLV). The increase of CoU concentrations in the first 3 h after the end of exposure, stresses the problem of when urine samples for biological monitoring of the workers should be collected. The present study confirms the utility of CoU in discriminating between exposed and non-exposed subjects as well as in assessing high and low level exposure.

Adult↗
PubMed1992

Pentasomy 21 in leukemia complicating Diamond-Blackfan anemia.

We present the cytogenetic pattern of a leukemic infant with Diamond-Blackfan anemia (DBA). The karyotype was characterized by clonal evolution involving consecutive gains of chromosome 21 up to pentasomy. No chromosomal changes were present in normal lymphocytes. Such a karyotype evolution has been described in some cases of acute leukemia associated with Down Syndrome, but rarely in non-Down cases.

Chromosomes, Human, Pair 21↗
PubMed1990

Linear porokeratosis: successful treatment with diamond fraise dermabrasion.

A patient with linear porokeratosis was successfully treated with diamond fraise dermabrasion. Follow-up evaluation revealed an excellent cosmetic result with adequate repigmentation, no scarring, and no recurrence of lesions. Long-term follow-up will be necessary to determine whether dermabrasion treatment of linear porokeratosis provides adequate prophylaxis against the subsequent development of malignancy.

Adult↗
PubMed1993

Diamond-like carbon: a potential means of reducing wear in total joint replacements.

This paper begins with a review of recent studies of the progressive mechanisms of degradation in total hip and knee replacements. It is concluded that wear is a major problem due to resulting tissue reactions especially to fine polymeric debris. Methods of lessening or overcoming these problems by modern methods of surface modification are considered, among these being ion implantation and ion beam-assisted deposition. It is argued that the physical and chemical properties of diamond-like carbon (DLC) coatings make them especially promising for the reduction of friction and adhesive wear in all forms of joint replacement. An ion beam-assisted method of depositing DLC efficiently at low temperatures is described, together with the physical properties of the resulting material.

Adhesiveness↗
PubMed1994

The effects of diamond-like carbon coatings on macrophages, fibroblasts and osteoblast-like cells in vitro.

The elaboration of metallic and polymeric particles from the wear of joint replacement components is widely implicated in the pathogensis of aseptic loosening of these implants. Diamond-like carbon (DLC) coatings show great potential as wear-retardant coatings and may offer a possible solution to this problem. We have studied the effects of DLC coatings on cells derived from the tissues that surround a total joint replacement (macrophages, fibroblasts and osteoblast-like cells). There was no evidence that DLC coatings, deposited on a variety of different substrates, caused cytotoxicity in vitro. Cells grown on the coated substrates exhibited normal cellular growth and morphology. DLC coatings are biocompatible in vitro and should now be tested in animal models to determine their behaviour in vivo.

Animals↗
PubMed2005

Diamond burr treatment of poor vision from anterior basement membrane dystrophy.

PURPOSE: To determine the outcome of patients with decreased vision associated with anterior basement membrane dystrophy (ABMD) managed with diamond burr (DB) polishing. DESIGN: Retrospective nonrandomized case series. METHODS: A chart review of all patients with ABMD who underwent epithelial debridement and DB polishing to treat visual disturbances resulting from corneal epithelial irregularity was performed. RESULTS: Ten patients' charts were analyzed. The mean age was 57.4 years. DB treatment was performed in 13 eyes. The average preoperative BCVA was 0.40 (20/50). At the last follow-up (mean 21.8 months) the average visual acuity of these patients was 0.88 (20/23), significantly better than pre-operative readings (P < .001). There was no recurrence of dystrophic changes in the treatment zone seen with the slit lamp during the follow-up period. CONCLUSIONS: In this study, DB polishing was shown to be an effective and safe treatment for decreased vision caused by to ABMD over an average follow-up of 21.8 months.

Basement Membrane↗
PubMed2006

Electrochemical behaviors of native and thermally denatured fish DNA in the presence of cytosine derivatives and porphyrin by cyclic voltammetry using boron-doped diamond electrode.

The electrochemical behaviors of native and thermally denatured fish DNA was investigated using boron-doped diamond (BDD) film electrode by cyclic voltammetry. The BDD electrode afforded us to measure weak current less than muA for the DNA solution in 100 microl. The mixture of acetic acid and sodium acetate solution (0.2 M) was used as a supporting electrolyte. Two oxidation peaks were observed at about +1.1 V and +1.3 V at pH 4.6 for thermally denatured fish DNA. This is due to the oxidation of guanine and adenine in the denatured fish DNA, respectively. In contrast, the native fish DNA showed ill-defined peaks at +1.1 V. Furthermore, the electrochemical behaviors of thermally denatured fish DNA were studied in the presence of cytosine, cytidine, cytidine-5-monophosphate, tetrakis(1-methypyridinium-4-yl)porphyrin (H(2)(TMPyP)(4+)) and Ru(II)(TMPyP)(4+). The oxidation peak intensity at +1.1 V gradually decreased with the increase of the concentrations of the above compounds. Based on the above studies, electrochemical behaviors of the thermally denatured fish DNA at BDD electrode is discussed.

Animals↗
PubMed2004

The diamond CO2 laser as a method of improving the vascularisation of a permanent collagen implant.

For a biomaterial to be considered as anything other than a simple filler material it must allow a certain degree of ingrowth from the surrounding host tissues. Permacol is a novel porcine derived biomaterial that is isocynate crosslinked to prevent its degradation in vivo, but while it appears to be biocompatible in terms of its histological tissue response, our early studies demonstrate only a limited degree of fibrovascular ingrowth. The aim of this study was to assess the effectiveness of both laser perforations and topically applied VEGF as methods of encouraging fibrovascular ingrowth. Treatment of Permacol with the diamond CO(2) laser significantly increased the porosity of the material as assessed by seescan image analysis. Fibrovascular ingrowth as assessed in the Sprague-dawley rat model was found to be limited to the pores themselves and not the surrounding native matrix. Pre-soaking of laser treated Permacol in vascular endothelial growth factor (VEGF) did not further increase fibrovascular ingrowth. Increasing the porosity of Permacol may allow its use as a dermal replacement in the support of an overlying skin graft or keratinocyte sheet; however using the laser may not be the optimal method of achieving this aim.

Animals↗
PubMed2004

SBDS mutations and isochromosome 7q in a patient with Shwachman-Diamond syndrome: no predisposition to malignant transformation?

Shwachman-Diamond syndrome (SDS) is a genetic disorder characterized by pancreatic hypoplasia, recurrent infection, and bone marrow (BM) dysfunction. SDS-patients have an increased frequency of myelodysplasia and leukemic transformation. Unspecific cytogenetic aberrations are a common finding in SDS. However, in a rising number of patients abnormalities of chromosome 7 have been reported, especially an i(7)(q10), which seems to be a non-random chromosome abnormality. Recently, the SDS gene has been mapped at locus 7q11 and subsequently cloned; recurrent mutations have been found. We report a case of SDS with an i(7)(q10) in the BM and two different mutations in the SBDS gene. At the age of 25 years, the patient suffers from mild aplastic anemia but does not show any clinical sign of myelodysplasia or leukemic transformation.

Adult↗
PubMed2006

Severe Shwachman-Diamond syndrome phenotype caused by compound heterozygous missense mutations in the SBDS gene.

OBJECTIVE: A 5-month-old male infant presenting with recurrent respiratory tract infections, chronic diarrhea, and failure to thrive was found to be pancytopenic. Bone marrow and x-ray examinations were consistent with Shwachman-Diamond syndrome (SDS). Genomic DNA sequencing, restriction fragment analysis, and studies of the mutant proteins were performed to gain further knowledge on the molecular pathology of SDS. MATERIALS AND METHODS: Exons 1 to 5 of the SBDS gene were amplified and sequenced. COS-7 cells were transfected with expression vectors containing wild-type cDNA or mutant cDNAs generated by site-directed mutagenesis. Protein expression of SBDS variants were examined by Western blotting. Pulse-chase assay and densitometry were used to study protein stability. RESULTS: Two novel missense mutations (c.362A > C in exon 3, and c.523C > T in exon 4) of the SBDS gene were identified in the patient. These mutations result in p.N121T and p.R175W amino acid replacements and correspond to amino acid residues that are highly conserved in SBDS proteins. In vitro expression studies revealed a markedly decreased half-life of the p.R175W protein, whereas stability of the p.N121T mutant was not significantly reduced compared to that of the wild type. CONCLUSION: This is the first report of compound heterozygous missense mutations occurring in patients with SDS. These mutations may not eliminate SBDS expression but may result in impaired protein stability and protein function leading to severe disease.

Animals↗
PubMed2004

Diamond iris retractor configuration for small-pupil extracapsular or intracapsular cataract surgery.

We describe a technique that uses flexible iris retractors in a diamond configuration for small-pupil extracapsular or intracapsular cataract surgery in eyes with unusually dense nuclear sclerosis. Advantages of this technique include ease of conversion from phacoemulsification, optimal orientation of the maximum pupil diameter for nucleus expression or intracapsular lens removal, and conservation of iris tissue.

Cataract↗
PubMed2004

Seasonal steroid hormone levels and their relation to reproduction in the Western Diamond-backed Rattlesnake, Crotalus atrox (Serpentes: Viperidae).

We report seasonal variation in steroid hormone levels in blood samples from free-ranging Western Diamond-backed Rattlesnakes (Crotalus atrox), and the relationship between these hormones and events in the reproductive cycle. At a field site in the Sonoran Desert of south-central Arizona, we collected monthly blood samples over the course of two active seasons from 17 radiotelemetered females, and over three active seasons from 103 randomly encountered males. We used radioimmunoassay to measure plasma levels of 17beta-estradiol, progesterone, corticosterone, and testosterone in samples from females, and corticosterone and testosterone in samples from males. Non-reproductive females have consistently low levels of circulating 17beta-estradiol, progesterone, and testosterone throughout the year. In reproductive females, 17beta-estradiol levels increase dramatically and testosterone levels increase modestly during vitellogenesis in April and May, while progesterone levels increase dramatically at ovulation in June and then steadily decline until parturition in August. Corticosterone levels appear relatively constant in non-reproductive females, whereas reproductive females show increased levels at the end of gestation. Plasma testosterone levels in males are low in early summer and are elevated during spring and late summer, corresponding to the two mating periods of C. atrox. Plasma corticosterone levels in males did not vary seasonally and were not related to testosterone levels.

Animals↗