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Biomedical subjects

N Pitts

Publications and source records attributed to N Pitts.

8 recordsLinked to original sources

Successful unrelated donor bone marrow transplantation for paroxysmal nocturnal hemoglobinuria.

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired clonal disease of hematopoiesis due to a mutation in the PIG-A gene. Affected patients may demonstrate hemolysis or venous thrombosis, and may develop MDS or aplastic anemia. Successful results may be obtained after conditioning and transplantation from syngeneic or genotypically matched sibling donors. Experience with transplantation from matched unrelated donors (MUD) is limited to eight patients, with only one survivor. We report three patients who underwent successful MUD BMT for PNH. All three patients had severe aplastic anemia (SAA) and PNH at the time of BMT. Unrelated donors were six-antigen HLA-matched (n = 2) or HLA-A mismatched (n = 1). Conditioning consisted of cytarabine, cyclophosphamide, TBI, and ATG. Grafts were T cell-depleted by anti-CD6/CD8 antibodies + complement. Further GVHD prophylaxis consisted of cyclosporine. Patients received 0.7-1.1 x 10(8) nucleated cells/kg and 1.1-2.1 x 10(6) CD34(+) cells/kg. Neutrophil engraftment occurred at 16-21 days. One patient developed grade 1 acute GVHD. Although all three patients experienced significant transplant-related complications, they ultimately resolved and all patients are alive and well 30-62 months after BMT. T cell-depleted MUD BMT is an effective treatment option for PNH-related MDS and SAA.

Adolescent↗

Allogeneic bone marrow transplantation for infants with acute leukemia or myelodysplastic syndrome.

The objective of this study is to investigate the outcome of children 24 months of age or younger (infants) at the time of allogeneic bone marrow transplantation (BMT) for acute leukemia or myelodysplasia. We analyzed the survival rate, prognostic factors, incidences of late sequelae, and immune reconstitution in 22 infants who underwent allogeneic BMT. The 5-year event-free survival estimate was 45.5% (95% confidence interval (CI), 24.4% to 63.3%). Six patients died of transplant-related complications and six died of disease relapse. Remission status at the time of BMT was the most important prognostic factor (P = 0.005): no patient who received a transplant while their disease was not in remission survived, whereas the 5-year survival estimate for infants who underwent BMT during remission was 56% (95% CI, 31% to 75%). Long-term outcomes in the 10 infant survivors were compared with those of 10 older controls matched for diagnosis, disease status at the time of BMT, calendar year at the time of BMT, and source of stem cells. Immune function 1 year after transplantation and the incidences and spectra of late sequelae were similar for both groups during a median of 3.5 years (range, 1.5 to 7.2 years) of follow-up.

Acute Disease↗

Electrical methods in occlusal caries diagnosis: An in vitro comparison with visual inspection and bite-wing radiography.

The aim of this study was to compare in vitro diagnostic performance of three electrical methods for occlusal caries diagnosis with that of visual inspection and bite-wing radiography. One hundred and seven extracted molar and premolar teeth were subjected to the diagnostic methods by 2 operators and subsequently sectioned for histological validation. Electrical measurements were made at site level and at surface level using two different instruments. The diagnostic parameters calculated from the results were: sensitivity, specificity, diagnostic accuracy at a theoretical caries prevalence of 10% and area under the ROC curve. The electrical methods and bite-wing radiography showed higher sensitivity and lower specificity than visual inspection. Diagnostic accuracy was significantly lower for bite-wing radiography and one electrical method than for visual inspection. Overall diagnostic performance of two electrical methods was superior.

Area Under Curve↗

Asking the academics.

Assumptions are no match for real consultation. As part of the MRI, the BDJ conducted a special survey to see if academic dentists could predict the primary care research priorities of general dental practitioners. How would the predictions differ from the priorities of the GDPs themselves?

Attitude of Health Personnel↗

Developments in radiographic caries diagnosis.

The developments that have been taking place in radiographic caries diagnosis, within the context of the changes occurring in both the disease process and the available technology, are reviewed. The decline in caries prevalence seen in many western countries has been accompanied by changes in the pattern and behaviour of lesions. More lesions are now seen on occlusal surfaces, more are concealed (and thus imperceptible to conventional diagnostic techniques), while the average progression rates for approximal lesions have also slowed. Systems employed for caries diagnosis must take account of these changes and the varying needs of users employing different diagnostic thresholds. This paper reviews and discusses developments in: conventional film radiography; xeroradiography; indirect digital imaging (with computer image analysis and subtraction radiography), and direct digital imaging. It is concluded that: for the detection in high caries prevalence groups of both approximal caries (especially small lesions in enamel) and dentinal occlusal lesions in teeth with little or no surface breakdown, radiography is still a significant and reasonably accurate diagnostic method; and that, in spite of the more limited resolution, digital imaging methods seem to perform as well or better than conventional film radiography. Digital systems possess a number of advantages, primarily the possibility for image enhancement and significant dose reduction. It may be predicted that digital imaging techniques will enter the clinical routine in the near future.

Dental Caries↗

Performance and reproducibility of a laser fluorescence system for detection of occlusal caries in vitro.

The diagnosis of occlusal caries at non-cavitated sites remains problematic, especially since clinical visual detection has limited sensitivity. Electrical methods of detection show considerable promise, but specificity is reduced. The aims of this in vitro study were: (1) to assess the validity of a new laser fluorescence device--the DIAGNOdent--(and compare the values with those of a fixed-frequency electrical device); (2) to determine the optimum cut-off points of the new device for different stages of the caries process, and (3) to assess the reproducibility of the new laser device. For validity and determination of optimum cut-off points, 105 extracted teeth with macroscopically intact occlusal surfaces were measured by a single examiner, using both the laser fluorescence device (on both moist and dried teeth) and an Electronic Caries Monitor. The teeth were subsequently examined histologically to determine the specificity, sensitivity and likelihood ratio at the D2 (caries extending through more than half of the enamel thickness) and D3 (caries involving dentin) levels. The values obtained for the laser device ranged from 0.72 to 0.87 (specificity), 0.76 to 0.87 (sensitivity) and 3.0 to 5.6 (likelihood ratio). Those for the ECM ranged from 0.64 to 0.78 (specificity), 0. 87 to 0.92 (sensitivity) and 2.4 to 4.1 (likelihood ratio). To determine intra- and interexaminer reproducibility of the DIAGNOdent, 11 dentists recorded two different measurements at the same site on a separate set of 83 extracted molar teeth, and these were compared using Cohen's kappa (at D2 and D3 levels) and Spearman's correlation coefficient. The average intra-examiner kappa scores were 0.88 (D2) and 0.90 (D3), with a Spearman correlation of 0.97. For interexaminer reproducibility, the average kappa values were 0.65 (D2) and 0.73 (D3), with a Spearman correlation of 0.84. It is concluded that for occlusal caries (1) the new laser device has a higher diagnostic validity than the ECM, and (2) in vitro, measurements using the device are highly reproducible. Thus, the laser device could be a valuable tool for the longitudinal monitoring of caries and for assessing the outcome of preventive interventions.

Dental Caries↗