Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Diamond”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 307 records · Page 17Linked to original sources
PubMed1998

Response to long-term hGH therapy in two children with Schwachman-Diamond syndrome associated with GH deficiency.

Schwachman-Diamond syndrome is a rare congenital disorder characterized by pancreatic insufficiency, metaphyseal anomalies, recurrent infections, hematologic abnormalities, and growth retardation. Slow growth in these patients has been attributed to nutritional deficits, recurrent infections, and skeletal anomalies. Two cases of Schwachman-Diamond syndrome associated with growth hormone deficiency have been previously reported. We report here on 2 additional cases with this unusual association. Therefore, growth failure in Schwachman-Diamond syndrome should not be assumed to be due to chronic illness or recurrent infections; other etiologies for growth failure should be sought. However, the presence of metaphyseal disorders probably interferes with the long-term efficacy of growth hormone substitutive therapy.

Adolescent↗
PubMed1990

WHO Multinational Project for Childhood Diabetes. WHO Diamond Project Group.

Insulin-dependent diabetes mellitus (IDDM) is one of the most important chronic diseases of children worldwide. IDDM leads to an 8- to 10-fold excess risk of mortality in developed countries, whereas in developing countries, most cases die within a few years. A 60-fold international gradient in IDDM incidence has been reported, and epidemic periods have been identified. A new World Health Organization program, Multinational Project for Childhood Diabetes (Diabetes Mondiale or DIAMOND), has been developed to investigate and characterize global incidence, mortality, and health care. Over 10 yr (1990-1999), this study will collect population-based data concerning IDDM in greater than 90 centers in 50 countries worldwide. The goals of DIAMOND are to collect standard information on incidence, risk factors, and mortality associated with IDDM; evaluate the efficiency and effectiveness of health care and the economics of diabetes; and establish national and international training programs in diabetes epidemiology. It is hoped that the DIAMOND project will be instrumental for the prevention of this serious disease and its sequelae.

Child↗
PubMed1992

[Comparison of wound healing of linear incisions in the rabbit cornea produced by the newly developed excimer laser, a metal blade, and a diamond blade].

We developed a new delivery system for corneal ablation with the 193 nm argon-fluoride excimer laser. The laser was used to make linear incisions in the rabbit cornea, and wound healing of the incisions was compared with the healing of incisions made with metal and diamond blades. The morphology of incisions made with excimer laser radiation (193 nm) was compared with the morphology of incisions produced by diamond and metal blades, and the corneal wound was examined by light and electron microscopy. The surface of the cornea at the site of the laser wound was smooth; the laser wound was wider than the blade wounds immediately after surgery. Two weeks after surgery, all wounds had healed equally. One month after surgery, there were fewer fibroblastic keratocytes in the laser wound, and the epithelial layer at the wound site was thinner than in the case of the blade wounds. These results suggest that wound healing of laser incisions is more rapid than healing of wounds created with metal or diamond blades.

Animals↗
PubMed1991

Diamond-Blackfan anemia: heterogenous response of hematopoietic progenitor cells in vitro to the protein product of the steel locus.

Diamond-Blackfan anemia is a congenital disorder of erythropoiesis in humans, characterized by a macrocytic anemia often associated with physical anomalies. Mutations at either the W or Steel loci in the mouse also leads to a severe macrocytic anemia, as well as other developmental abnormalities. The W locus encodes the proto-oncogene c-kit, a member of the receptor tyrosine kinase family, while the Steel locus encodes a potent hematopoietic growth factor that is the ligand for c-kit. Growth of clonogenic marrow erythroid progenitor cells in vitro in the presence of the recombinant hematopoietic growth factors interleukin-3 (IL-3) and Steel was used to characterize this disease at the cellular level. Three patterns of in vitro marrow response to both recombinant IL-3 or Steel were observed among 10 Diamond-Blackfan patients: those that responded quantitatively and qualitatively almost as well as cells from normal marrow, those that responded at an intermediate level, and those that did not respond at all. These results provide evidence for cellular heterogeneity underlying the pathogenesis of this disorder and therefore raise the possibility that there may be more than one underlying molecular basis for the disease. No gross abnormalities in the structure of either the c-kit or Steel loci were observed in these patients. The normal response in culture of the progenitor cells from at least some patients to Steel with or without IL-3 raises the possibility of using this novel growth factor as a therapeutic agent in Diamond-Blackfan anemia.

Adolescent↗
PubMed1990

[Fine polishing of Cerec inlays using diamond polishing systems].

The surface roughness of Cerec-inlays after polishing with diamond polishing pastes or Diafinish-disks was compared to polishing with aluminium oxide disks (AOD). SEM evaluation of the occlusal surface of extracted teeth revealed that diamond polishing pastes or Diafinish-disks produced smoother surfaces than AOD. The pastes, however, damaged the bonding resin. It is recommended to use AOD and diamond polishing systems for the approximal surfaces of the inlays extraorally. Intraorally AOD or Diafinish-disks are recommended.

Dental Polishing↗
PubMed1994

Diamond-blackfan anemia in pregnancy.

BACKGROUND: Diamond-Blackfan anemia is a rare form of congenital red-cell aplasia. Approximately 90% of the patients are diagnosed by 1 year of age. This report presents two pregnancies with good outcomes in a patient over a period of 1.5 years. CASE: The patient, a 20-year-old woman, was diagnosed with Diamond-Blackfan anemia at age 3.5 months. Treatments consisted of red blood cell transfusions and oral corticosteroids. She conceived at age 18 years and delivered prematurely at 34 weeks' gestation. Her second pregnancy was diagnosed 4 months after delivery of the first child, and she delivered spontaneously at 38 weeks and 6 days' gestation. She received multiple blood transfusions during both of the pregnancies. The infants were average for gestational age and had normal examination at birth. CONCLUSION: Based on this case and a review of the literature, it appears that pregnancy and birth control pills may contribute to the relapse of anemia in patients diagnosed with Diamond-Blackfan syndrome. This may require an increase in the frequency of blood transfusions. Pregnancies are usually tolerated well and can be managed with supportive therapy.

Adult↗
PubMed1997

[Diamond-Blackfan syndrome: pregnancy and heredity].

Diamond-Blackfan syndrome is a rare bone marrow failure involving the erythropoietic lineage and usually diagnosed in the first year of life. About 80% of cases are sporadic but there are examples of recessive and dominant inheritance. Whether the variable pattern of inheritance observed in pedigrees of Diamond-Blackfan syndrome reflects different genetic determinants of the disease remains uncertain. Family studies with use of the newer tools of molecular biology will produce improved insight into the genetic origin of this disease. A review of pregnancy associated Diamond-Blackfan syndrome indicated an increase in pregnancy complications. It appears that pregnancies are usually well tolerated and can be managed with supportive care and blood transfusions.

Adrenal Cortex Hormones↗
PubMed1991

Imaging friction tracks at diamond surfaces using reflection electron microscopy.

Reflection electron microscopy (REM) is applied to image the structure of polished natural diamond (001) surfaces (of 5 x 4 mm size) after friction experiments under a pressure below the critical value. Friction tracks marked by a diamond needle after a single pass movement under a pressure of 13 GPa can be seen in REM images and show non-uniform contrast. The surface shows relatively dark image contrast at the light contacted area, which is possibly due to the structural modification at the top atomic layer. The high local contacting pressure pushes part of the needle into the surface which causes fracture, resulting in the formation of grooves at the surface. It is possible to have plastic deformation in this process, but no evidence has been found for the presence of cracking. The observations support the adhesion frictional mechanism rather than the micro-cleavage model.

Carbon↗
PubMed2006

Controlling thermal damage of incisions using diamond, copper, and sapphire heat-conducting templates with and without cooling.

INTRODUCTION: We investigated the reduction of thermal damage to the surrounding tissue when laser incisions were made with and without using thermal conducting templates at room temperature and cooled to 5 degrees C. STUDY DESIGN/MATERIALS AND METHODS: We used the Vanderbilt free-electron laser (FEL) at 5.4, 6.1, 6.45, and 7.7 microns. We also used a conventional continuous wave (CW) carbon dioxide laser at 10.6 microns. Incisions were made on 5x10 mm pieces of human breast skin (in vitro) and analyzed with histology. Computer morphometrics were used to measure the amount of thermal damage. RESULTS: All templates produced a statistically significant reduction in the thermal damage. Additionally, we showed that cooling the templates made a statistically significant greater reduction in the thermal damage. The cooled diamond template reduced the thermal damage from the FEL to 28% of the damage observed without a template. The same cooled template reduced the thermal damage from the CO(2) laser to 56% of the damage observed without a template. Lesser reductions were observed with the copper template and even less with the sapphire template. The sapphire template reduced the thermal damage to 39 and 67% of the damage observed without a template for the FEL and the CO(2) laser, respectively. CONCLUSION: These results indicate that unwanted lateral thermal damage from laser incisions can be reduced with cooled thermally conductive templates with the best results obtained with the diamond template, which is also the best thermal conductor.

Aluminum Oxide↗
PubMed2004

Mercury-free sono-electroanalytical detection of lead in human blood by use of bismuth-film-modified boron-doped diamond electrodes.

We report the electroanalytical determination of lead by anodic stripping voltammetry at in-situ-formed, bismuth-film-modified, boron-doped diamond electrodes. Detection limits in 0.1 mol L(-1) nitric acid solution of 9.6 x 10(-8) mol L(-1) (0.2 ppb) and 1.1 x 10(-8) mol L(-1) (2.3 ppb) were obtained after 60 and 300 s deposition times, respectively. An acoustically assisted deposition procedure was also investigated and found to result in improved limits of detection of 2.6 x 10(-8) mol L(-1) (5.4 ppb) and 8.5 x 10(-10) mol L(-1) (0.18 ppb) for 60 and 300 s accumulation times, respectively. Furthermore, the sensitivity obtained under quiescent and insonated conditions increased from 5.5 (quiescent) to 76.7 A mol(-1) L (insonated) for 60 s accumulation and from 25.8 (quiescent) to 317.6 A mol(-1) L (insonated) for 300 s accumulation. Investigation of the use of ultrasound with diluted blood revealed detection limits of the order of 10(-8) mol L(-1) were achievable with excellent inter- and intra-reproducibility and sensitivity of 411.9 A mol(-1) L. For the first time, electroanalytical detection of lead in diluted blood is shown to be possible by use of insonated in-situ-formed bismuth-film-modified boron-doped diamond electrodes. This method is a rapid, sensitive, and non-toxic means of clinical sensing of lead in whole human blood.

Bismuth↗
PubMed2004

Nucleosides and ODN electrochemical detection onto boron doped diamond electrodes.

Boron doped diamond (BDD) is a promising material for electroanalytical chemistry due mainly to its chemical stability, its high electrical conductivity and to the large amplitude of its electroactive window in aqueous media. The latter feature allowed us to study the direct oxidation of the two electroactive nucleosides, guanosine and adenosine. The BDD electrode was first activated by applying high oxidizing potentials, allowing to increase anodically its working potential window through the oxidation of CH surface groups into hydroxyl and carbonyl terminations. Guanosine (1.2 V vs. Ag/AgCl) and adenosine (1.5 V vs. Ag/AgCl) could then be detected electrochemically with an acceptable signal to noise ratio. The electrochemical signature of each oxidizable base was assessed using differential pulse voltammetry (DPV), in solutions containing one or both nucleosides. These experiments pointed out the existence of adsorption phenomena of the oxidized products onto the diamond surface. Scanning electrochemical microscopy (SECM) was used to investigate these adsorption effects at the microscopic scale. The usefulness of BDD electrodes for the direct electrochemical detection of synthetic oligonucleotides is also evidenced.

Adenosine↗
PubMed2006

Electrochemical oxidation of benzene on boron-doped diamond electrodes.

This work presents an electrochemical investigation of the benzene oxidation process in aqueous solution on boron-doped diamond (BDD) electrodes. Additionally, in order to determine the main products generated during the oxidation process, electrolysis and high performance liquid chromatography experiments were carried out. The complete degradation of this compound was performed aiming to a further application in waste water treatment. The cyclic voltammetry studies indicate that benzene is irreversibly oxidized in acid medium (H2SO4 0.5 M) on the BDD electrode surface at 2.0 V versus Ag/AgCl in a diffusion controlled process. During the cycling, other products are generated, and a pair of peaks was observed that can be associated with the oxi-reduction of anyone of the following species: hydroquinone, benzoquinone, resorcinol or catechol. The electrolysis experiments were carried out at 2.4 and 2.5 V on the BDD electrode surface in a solution containing 1x10(-2) M of benzene (below the saturation concentration in aqueous solution), for 3 and 5 h, respectively. The main products measured were: hydroquinone, resorcinol, p-benzoquinone, catechol and phenol. The complete electrochemical benzene degradation was performed in the electrolysis experiments using a rotating BDD disc electrode (2.5 V for 5 h) and the main products detected were all measured at concentrations lower than 10(-5) M in this condition. The boron-doped diamond electrode had proved to be a valuable tool for the electrochemical degradation of the benzene, a very stable chemical compound.

Benzene↗
PubMed2005

Analysis of the 16 Environmental Protection Agency priority polycyclic aromatic hydrocarbons by high performance liquid chromatography-oxidized diamond film electrodes.

The capabilities of using boron-doped diamond (BDD) thin films as electrode materials for analysis of the 16 US Environmental Protection Agency (EPA) priority polyaromatic hydrocarbons (PAHs) after a liquid chromatographic separation were evaluated. The BDD electrode was able to detect all 16 PAHs with high sensitivity due to the low background current and wide potential window. The method provided detection limits ranging from 12-40 nM (3-10 ppb) and repeatable results over consecutive analysis. Calibration curves were linear up to at least 10 microM for all PAHs. The work shows the promising use of diamond as an amperometric detector in high performance liquid chromatography (HPLC), especially for PAHs and other hydrophobic aromatic compounds.

Boron↗
PubMed2004

Endovascular treatment of superficial femoral artery occlusive disease with stents coated with diamond-like carbon.

A major consideration in the reduction of early stent thrombosis and in-stent restenosis is the improvement of biocompatibility of the devices. Diamond-like carbon is a novel material for coating stent surfaces in order to increase biocompatibility. The authors report on the endovascular treatment of two individuals with superficial femoral artery occlusions, using stents coated with diamond-like carbon. Technical and clinical success was achieved in both cases, with primary patency rates of 100% 12 months after intervention.

Aftercare↗
PubMed2006

The functions of RPS19 and their relationship to Diamond-Blackfan anemia: a review.

The relatively new study of ribosomal proteins has allowed for greater understanding of protein synthesis; however the connection between ribosomal proteins' roles and that of disease pathophysiology has not yet been established. RPS19 is a ribosomal protein linked to Diamond-Blackfan anemia whose functions have begun to be elucidated. We review here the known roles of RPS19 in both ribosome construction and other extra-ribosomal functions and discuss their relationship to Diamond-Blackfan anemia.

Anemia, Diamond-Blackfan↗
PubMed2003

Glial cell and fibroblast cytotoxicity study on plasma-deposited diamond-like carbon coatings.

Diamond-like carbon films have been evaluated as coatings to improve biocompatibility of orthopedic and cardiovascular implants. This study initiates a series of investigations that will evaluate diamond-like carbon (DLC) as a coating for improved biocompatibility in chronic neuroprosthetic implants. Studies in this report assess the cytotoxicity and cell adhesion behavior of DLC coatings exposed to glial and fibroblast cell lines in vitro. It can be concluded from these studies that DLC coatings do not adversely affect 3T3 fibroblast and T98-G glial cell function in vitro. We also successfully rendered DLC coatings non-adhesive (no significant fibroblast or glial cell adhesion) with surface immobilized dextran using methods developed for other biomaterials and applications. Future work will further develop DLC coatings on prototype microelectrode devices for chronic neural implant applications.

3T3 Cells↗
PubMed2003

Study of induced thermoluminescence in CVD diamond film by low-energy X-rays.

For diamond film the one-hit model that is used to interpret low-energy X-ray thermoluminescence (TL) will require some modifications. After the films were irradiated with a superficial X-ray machine with different peak voltages, a two-compartment model with three parameters, the target size, the microscopic saturation factor and the high-LET saturation factor, was used to more precisely describe the TL response to X-ray with energies down to 10 kV. The microdosimetric distribution was calculated using single-event Monte Carlo code developed by authors together with EEDL cross-section data library. Some mechanistic insight into the physical aspect of radiation interaction with solid detectors can be obtained. The sensitive size in diamond was found to be about 15 nm. The saturation of one group of sublevels combined with the activation of another group of sublevels caused the relative efficiency to have a local minimum near 20 keV. The relative efficiency becomes higher below 10 keV, which is similar to the increasing relative biological effectiveness when the linear energy transfer passing through a biological system increases. The similarity made this material to be a molecular-scale dosimeter in the future.

Cobalt Radioisotopes↗
PubMed1998

Diamond fraise technique for dermal grafts in temporomandibular disk reconstruction.

Dermal grafts have been described for a variety of applications, including preprosthetic surgery, reconstructive surgery, and temporomandibular joint surgery. Several reports have described the procedural techniques for acquiring a dermal graft. The surgical technique for harvesting a dermal graft with the use of the dermabrading diamond fraise bur is described. The use of the diamond fraise bur offers many unique surgical advantages: it allows minimal damage to the dermal layer; the healing surface is smooth, cosmetic, homogenous, and devoid of scratches or debris; an adequate graft of uniform thickness is obtained; the technique allows access to a variety of donor sites; and minimal patient postoperative donor site morbidity. The use of this technique provides a simple, cosmetic approach to obtaining an adequate dermal graft for temporomandibular joint reconstructive procedures, while minimizing the potential complications associated with other commonly used techniques.

Adipose Tissue↗