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B L Sheridan

Publications and source records attributed to B L Sheridan.

13 recordsLinked to original sources
PubMed1995

An automated hematology laboratory with computer-controlled robotics.

A highly automated hematology laboratory environment is described that has conveyance systems to move bar-coded specimens from one station ("workcell") to another, robotic handling devices to load and unload hematology analyzers, and a hematology workstation. Computer systems monitor the process and equipment, track the specimen, manage inventory, and interpret patient results. When a specimen arrives at the laboratory, the bar-code determines which workcell the specimen should go to for testing. Each specimen is handled individually and in real-time. Hematology specimens are routed to a workcell of Coulter STKS analyzers where complete blood counts with five-part leukocyte differentials are performed under full robotic control. The entire process is managed by a real-time Windows-based process control system that interacts with a networked laboratory information system. The hematology workstation is being evaluated for interpretive results reporting and to determine follow-up testing.

Clinical Laboratory Information Systems↗
PubMed1994

Evaluation of the Roche Cobas Argos 5Diff automated haematology analyser with comparison to a Coulter STKS.

The performance of the Roche Cobas Argos 5Diff (Argos) automated haematology analyser was evaluated by comparison to manual blood film examination and a Coulter STKS (STKS) analyser. The Argos demonstrated excellent between and inter-batch imprecision for all parameters, except the MCHC, and good linearity for Hb, WBC and platelet count (PLT). After an initial fall the PLT, results were stable for up to six h at 18 degrees C in EDTA(K3) after which an increasing proportion of cells were classified as lymphocytes. Results of 239 patient samples analysed on both instruments, compared by linear regression, gave excellent correlation (r2 > 0.90) for most parameters with the exceptions of the MCHC (0.317), eosinophils% (0.756), monocytes% (0.48) and basophils% (0.002). 'Flagging' of cellular abnormalities by the Argos resulted in excellent sensitivity (97.5%), specificity (93.2%) and efficiency/agreement (93.2%), with fewer false positive and negative results than the STKS, although these differences were not statistically significant. The performance characteristics of the Argos were comparable to those of the STKS with a possible improvement in its flagging abilities.

Autoanalysis↗
PubMed1991

Essential thrombocythemia with the Philadelphia chromosome and BCR-ABL gene rearrangement. An entity distinct from chronic myeloid leukemia and Philadelphia chromosome-negative essential thrombocythemia.

A 64-year-old woman presented with a platelet count of 3,225 x 10(9)/L. Bone marrow morphology showed massive megakaryocytic hyperplasia; cytogenetic studies showed the presence of the Philadelphia chromosome (Ph). The presence of a rearrangement involving the major breakpoint cluster region (mbcr) on chromosome 22 was confirmed by Southern blotting techniques. A diagnosis of Ph positive essential thrombocythemia (ET) was made. Such cases constitute less than 5% of patients with ET and it has been proposed that they be considered examples of chronic myelogenous leukemia (CML) because of a shared propensity to progress to blast crisis. An argument is presented for retaining Ph positive ET as an entity separate from Ph negative ET and Ph positive CML.

Blotting, Southern↗
PubMed1991

Synovial fluid immunocytology in the diagnosis of leukemic synovitis.

We describe a patient with leukemic synovitis complicating acute lymphoplastic leukemia. Leukemic cells were identified in the synovial fluid by an indirect immunofluorescent technique using monoclonal antibodies against early B cell antigens. Since focal leukemic lesions may be missed in synovial biopsy specimens, immunocytological analysis of joint fluids may facilitate early diagnosis of leukemic arthritis.

Adult↗
PubMed1990

Oncogene involvement in myelodysplasia and acute myeloid leukemia.

The clonal malignancies of acute myeloid leukemia and the myelodysplastic syndromes are associated with numerous chromosomal and oncogenic abnormalities. Activation of oncogenes has been demonstrated, although there is little evidence that this alone causes malignant transformation of diploid cells as a consequence. Patterns of abnormalities can be seen as the patient progresses from myelodysplastic syndrome to acute myeloid leukemia, but no unique or invariant findings have been described. Chromosomal changes, with the exception of some translocations, are neither disease nor lineage specific. At this time the data provide good support for the multistep view of carcinogenesis, and there is indirect or circumstantial evidence for the presence of tumor suppressor genes on 5q and 7q. The continued study of these clonal hematological disorders will provide considerable insight into mechanisms of tumorigenesis and possibly may lead to new modes of therapy, for example, through altering the microenvironment, interfering with deranged signal transmission, or introducing antioncogenes.

Acute Disease↗
PubMed1986

Effects of cod-liver oil on intimal hyperplasia in vein grafts used for arterial bypass.

Cod-liver oil rich in eicosapentaenoic acid, an unsaturated fatty acid, has been shown to inhibit platelet aggregation. To determine the effect of this acid on vein-graft intimal hyperplasia, 46 segments of undistended external jugular vein were interposed between the bilaterally divided femoral arteries of 26 mongrel dogs. The animals received a 2% cholesterol diet for 1 week before and 6 weeks after the operation. Eight control animals received the diet alone, eight received cod-liver oil containing 1.8 g of eicosapentaenoic acid daily, for 1 week before and 6 weeks after operation, and seven animals received 1.8 g of eicosapentaenoic acid daily for 6 weeks after operation. Intimal thickness was measured at 6 weeks with a Zeiss computerized interactive image analysing system from multiple cross-sections of vein graft; 395 +/- 10 measurements were made from each graft. The intima measured 4 +/- 0.2 micron (SEM) before implantation and increased to 83 +/- 10 micron in the controls. Eicosapentaenoic acid administered before and after operation reduced intimal hyperplasia to 24 +/- 2.5 micron (p less than 0.001) and to 30 +/- 5 micron in animals receiving eicosapentaenoic acid after operation only (p less than 0.001). These results indicate that the acid inhibits intimal hyperplasia of canine vein grafts but that it is more effective when given before operation (p less than 0.01).

Animals↗
PubMed1986

Reduction of intimal hyperplasia in canine autologous vein grafts with cod-liver oil and dipyridamole.

To determine the effects of cod-liver oil and a combination of cod-liver oil and dipyridamole on vein-graft intimal hyperplasia, 76 segments of undistended jugular vein were interposed between bilaterally divided femoral arteries in 38 mongrel dogs who received a 2% cholesterol diet. Ten control animals received the diet alone, 8 received cod-liver oil containing 1.8 g of eicosapentaenoic acid daily 1 week before and for 6 weeks after operation, and 20 dogs received 1.8 g of eicosapentaenoic acid and 75 mg of dipyridamole daily 1 week before and for 6 weeks after operation. A similar and significant (p less than 0.01) increase in serum cholesterol was observed in all three groups. Prothrombin, partial thromboplastin and clotting times and the platelet count were unchanged in the controls and in those receiving cod-liver oil. Clotting time increased in the animals receiving a combination of cod-liver oil and dipyridamole (p less than 0.001). Measurements (406 +/- 27) of intimal thickness were made from each graft. Intimal thickness was 3.7 +/- 0.1 micron before implantation and increased to 78 +/- 8 micron after in the controls. Cod-liver oil limited the increase in intimal thickening, to 24 +/- 3 micron (p less than 0.001); cod-liver oil and dipyridamole further reduced the increase in intimal thickening, to 17 +/- 1.4 micron (p less than 0.001). The data indicate that a combination of cod-liver oil and dipyridamole is more effective than cod-liver oil alone in reducing canine vein-graft intimal hyperplasia (p less than 0.03).

Animals↗
PubMed1985

Vitamin B12 assays compared by use of patients' sera with low vitamin B12 content.

We compared four radioisotope dilution (RD) methods and a microbiological assay for measuring concentrations of vitamin B12 in a selected panel of serum samples from patients known to be deficient in the vitamin. Low (less than 100 ng/L) and borderline (100-180 ng/L) results were similar between methods, but use of the manufacturers' recommended ranges for borderline results would have changed the diagnostic classifications for 22 of 38 samples. Results of all the RD methods inter-correlated well, but less so with the microbiological assay. Borderline, nondiagnostic results were common to all methods, and no apparent advantage was gained from using the microbiological assay.

Adult↗
PubMed1976

The patterns of fetal haemoglobin production in leukaemia.

Elevated levels of haemoglobin F (Hb F) have been foudn in a wide range of haematological malignancies, but very high levels were found only in juvenile chronic myeloid leukaemia (JCML), and erythroleukaemia occurring in infancy. In both these disorders a reversion to a fetal form of erythropoiesis may occur, as judged by both the structure of the Hb F and by the disappearance of Hb A2 and the carbnoic-anhydrase isozymes during the course of the illness. The clinical picture of JCML is not always associated with a reversion to fetal erythropoiesis; there appears to be a heterogeneity of conditions with this clinical label. Thus the reversion to a completely fetal pattern of erythropoiesis seems to occur in a variety of leukaemias which start in early life. This change is associated with a uniformly bad prognosis. Of a group of 17 patients with acute myeloid leukaemia 15 developed an increase in the level of Hb F about 60 days after the commencement of treatment; significantly greater increases were observed in those achieving a clinical remission. The level of Hb F usually declined during remission but high levels persisted in a few cases. Increased levels of Hb F were found also in patients with other haematological malignancies who had undergone periods of marrow aplasia during treatment. In all cases the Hb F was heterogeneously distributed throughout the red cells. Analysis of gamma15 or gammaCB3 peptides of Hb F from a variety of leukaemias gave glycine compositions ranging from 0.20 to 0.85 residues with many values in the fetal range; all cases with a reversion to fetal erythropoiesis had values in the fetal range. Attempts to confirm the 'fetal' origin of the cells containing Hb F by means of other markers was possible only in the cases of JCML and in one child with erythroleukaemia. These studies indicate that in some forms of leukaemia there may be a genuine reversion to fetal erythropoiesis while in others the emergence of cells containing Hb F appears to be part of a rapid regeneration process occurring after a period of marrow aplasia. The diagnostic and prognostic value of these observations is discussed.

Adult↗