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J M England

Publications and source records attributed to J M England.

At least 55 records · Page 3Linked to original sources
PubMed1982

The UK National External Quality Assessment Scheme in Blood Group Serology, Compatibility testing 1979-1980.

Seven proficiency tests in compatibility testing were issued in 1979 to 1980. In each exercise participants were required to test five sera, most of which contained alloantibodies, against three samples of red cells by three designated techniques, namely agglutination in saline at room temperature, agglutination in albumin at 37 degrees C and the antiglobulin test at 37 degrees C. Comparability was achieved by scoring of results. Incompatibilities were missed by 3.5 to 22% of participants in five exercises in which undiluted antibodies were issued. There was no significant improvement in performance over two years. Antibodies which were issued diluted, but detectable by antiglobulin test, were missed with high frequency.

Agglutination Tests↗
PubMed1982

Estimation of lymphocyte percentage and number on the Coulter Counter, Model S Plus Phase II.

The Coulter Counter Model S Plus Phase II provided precise measurements of lymphocyte percentage and count and carry-over was negligible. Lymphocyte percentage values agreed well with those from the stained blood film except when the percentage was high and in these circumstances the instrument gave underestimates. When making artificial mixtures with increasing lymphocyte count a progressive underestimation of the lymphocyte percentage was also noted. The display of leucocyte volume distribution was found to be a useful attribute particularly when the instrument alerted the operator to "rejected" profiles. Rejection by the instrument proved to be a helpful function occurring in the myeloid leukaemias, erythroblastosis, and in some cases when the lymphocytes differed from normal--for example, glandular fever and chronic lymphocytic leukaemia.

Humans↗
PubMed1982

The UK national external quality assessment scheme in blood group serology. Compatibility testing 1979-1980: trends and performance in relation to practice in antiglobulin testing.

Surveys of antiglobulin test procedures and reagents were undertaken in 1979-1980 as part of a national external quality assessment scheme in compatibility testing. An extraordinary lack of standardization was revealed. In addition, practices underwent considerable changes over this period. The use of tube and of low ionic strength solution (LISS) techniques increased whilst the use of tile and of albumin-antiglobulin techniques declined. Performance in compatibility test exercises was significantly better with tube techniques than with tile techniques in 9/22 incompatibilities. Performance with LISS techniques was occasionally significantly better than with normal ionic strength techniques. Performance with albumin-antiglobulin techniques was occasionally significantly worse than in the absence of albumin. To varying extents significant relationships were found between performance and cell concentration, serum/cell concentration ratio, antiglobulin reagent and method of reading the results.

Blood Grouping and Crossmatching↗
PubMed1982

An assessment of the Ortho ELT-8.

The Ortho ELT-8 is an automated blood counter which appears to be safe, precise and free from carry-over. Red and white cell results generally agree with those on the Coulter Counter, Model S, though discrepancies were noted with the WBC and PCV. Reference methods showed the Model S WBC results tended to be inaccurate on the discrepant samples though neither instrument was predominantly responsible for the PCV discrepancies. The ELT-8 platelet count tended to be higher than with the Thrombocounter/Thrombofuge system. When packed cells were diluted in autologous plasma serious variations in the red cell indices (MCV, MCH & MCHC) were first found due to incorrect voltage-frequency converter setting. Even after this setting had been corrected some variations in the MCH and MCHC were still apparent. In the UK National External Quality Assessment Scheme the ELT-8 results on animal bloods did not agree with those produced by Model S users; this discrepancy probably being due to differences between the light-scattering and aperture-impedance technology.

Blood Cell Count↗
PubMed1981

Expression of endogenous retroviral envelope antigen in Ig(+) B cells of immunized 15I5 X 71 chickens.

In a previous study (1), we observed that antigen cross-reactive with structural protein of the endogenous retrovirus RAV-O is expressed in splenic Ig(+) B lymphocytes of immunized 15I5 X 71 chickens. The present experiments were undertaken to determine the relationship of this antigen to viral gag- and env-coded antigenic specificities. As analyzed by immunofluorescence with several antisera, group-specific determinants of the gp85 envelope glycoprotein as well as viral-related type E-specific determinants were detectable in islands of Ig(+) splenocytes; antigenic determinants of viral gag protein were not detected in the splenic islands. These observations indicated that antigen cross-reactive with endogenous retroviral envelope glycoprotein is expressed in Ig(+) B cells.

Absorption↗
PubMed1981

Endogenous retroviral envelope antigen in plasma cells.

Previous observations that endogenous retroviral envelope antigen is expressed in splenic Ig(+) B cells of SRBC-sensitized 15I5 X 71 chickens suggested that expression of this antigen might be a general property of plasma cells in 15I5 and related strains. To investigate this possibility, immunofluorescence assays with antiviral sera were carried out using plasma cells present in Harder glands. Endogenous retroviral envelope antigen was detectable in plasma cells of line 15I5 X 71, 15I5 X 72, and 15I5 chickens but not in plasma cells of line 72, 15B, or 63 chickens. Higher levels of retroviral envelope antigen were detectable in 15I5 X 71 plasma cells as compared to 15I5 X 71 bursal cells. The presence of retroviral envelope antigen in 15I5 plasma cells, coupled with the absence of detectable levels of retroviral p27-related antigen in these cells, suggested that expression of the former is governed by the ev 6 genetic locus.

Animals↗
PubMed1980

Problems with the serum vitamin B12 assay.

Quality control trials have shown that, in routine practice, serum vitamin B12 estimations vary so much from laboratory to laboratory that serious confusion can result irrespective of whether microbiological or radioassay methods are used. Even experienced centres find the assay too insensitive and non-specific for a low level to be used as the sole criterion of vitamin B12 deficiency; the haemopoietic and biochemical sequelae of vitamin B12 deficiency also correlate poorly with the serum level. These basic difficulties with the assay seem to stem from the pattern of vitamin B12 (or cobalamin) binding in serum. Human beings are unique in having virtually all of their cobalamin attached to an apparently functionless binder, transcobalamin I. It is therefore not surprising that the serum cobalamin is such a poor predictor of cobalamin deficiency. The metabolically important serum binder is transcobalamin II and deficiency of this protein causes a potentially lethal megaloblastic anaemia even though the serum cobalamin level is normal. Tissue cobalamin depletion with normal serum levels also occurs after nitrous oxide inhalation and in certain inborn errors of metabolism.

Anemia, Megaloblastic↗
PubMed1979

Discrimination between iron-deficiency and heterozygous-thalassaemia syndromes in differential diagnosis of microcytosis.

Three formulae have been advocated for interpreting the blood-count when differentiating between iron deficiency and heterozygous thalassaemia: the discriminant function. M.C.V.-R.B.C.-(5 X Hb)-k, the M.C.V/R.B.C. ratio, and the (M.C.V.)2 X M.C.H. product. In a comparison of their diagnostic accuracy in microcytic adults from several countries, the discriminant function was the most satisfactory. 417 of 455 uncomplicated cases (91.6%) of iron deficiency, heterozygous alpha1- and beta- thalassaemia were correctly identified. The function was not able to distinguish heterozygous alpha2-thalassaemia from iron deficiency. A flow chart illustrates how the discriminant function can be used in haematological practice.

Anemia, Hypochromic↗
PubMed1979

Distribution of endogenous cobalamin between the transcobalamins in various mammals.

1. Plasma samples from ten mammals were chromatographed on Sephadex G-200 columns and the total cobalamin content of each fraction was determined. 2. Unlike the situation in man, the bulk of the endogenous plasma cobalamin was found attached to a transcobalamin II-like protein in all ten animals. Transcobalamin 0 carried between 3 and 20% and this proportion appeared to be inversely related to the plasma total cobalamin. No endogenous cobalamin peak corresponding to transcobalamin I was detected in any species, though in the rabbit 5.3% of the plasma total cobalamin was attached to a protein of apparent molecular weight 176 000.

Animals↗
PubMed1979

Endogenous oncornaviral antigen in the bursa of Fabricius of 15B X 7(2) chickens.

Oncornaviral antigen was detected in the bursal epithelium and in a subpopulation of bursal follicular cells of 15B X 72 chickens. This antigen is present in the bursal epithelium at 11 days of embryogenesis and persists there for at least 3 weeks after hatching. The absence of detectable antigen in the intestinal epithelium contiguous to the bursal epithelium indicates that the accumulation of viral antigen is a specific property of the bursal epithelium. The observation of C-type particles in the intraepithelial spaces suggests that the viral antigen in synthesized and assembled into virions by the bursal epithelial cells. In embryonic bursas, viral antigen-positve cells radiate from the surface epithelium toward the central region of the follicles. In bursas from post-hatch chickens, viral antigen-positive cells, including intrafollicular epithelial cells and cells resembling lymphocytes, are confined to the medullary region of the follicles.

Animals↗
PubMed1979

Determinants of haemoglobin level in sickle cell-haemoglobin C disease.

The determinants of steady state haemoglobin levels in sickle cell-haemoglobin C (SC) disease were investigated by measuring routine haematological and biochemical indices, red cell survival, oxygen affinity, pitted erythrocytes, and red cell and plasma volumes in 31 adult patients (15 male; 16 female). Red cell survival was shortened in all subjects, and was positively correlated with haemoglobin level. However, many haemoglobin values were within the normal range, especially in male subjects. Palpable splenomegaly, which occured in 53% of patients, did not appear to affect haemoglobin level, red cell survival, plasma volume, or red cell volume, but was associated with lower platelet counts and decreased pitted red cells. Sex related differences were found in total haemoglobin, packed cell volume, conductivity cell volume, red cell count, and in the blood volume measurements. Red cell, plasma and total blood volumes in patients varied with weight and cube of height in manner observed in normal subjects, although red cell volumes were lower and plasma volumes were greater than in normal subjects of given height and weight. Anaemia in SC disease is related to the haemolytic rate but the major determinant appears to be an inappropriate increase in plasma volume.

Adolescent↗
PubMed1979

A minicomputer laboratory data-management system: the St. Mary's system and its haematology applications.

The computer system developed at St Mary's Hospital Medical School, and now used in six hospital haematology laboratories, is described. The system allows for the rapid retrieval of pathology results from an archive of at least 180 000 records on a 10 megabyte disk. Two main data files are used, the "Current File", from which reports are prepared, and an "Archive File" which contains cumulated results. The files are indexed by parts of both the name and, if available, the hospital number. Patient linkage is accomplished using the whole known identification, but, unlike most other systems, no absolute requirement is placed on the existence of a hospital number. It is concluded that this method of patient linkage removes many of the management overheads associated with hospital number linked systems, and that use of the computer not only aids reporting, but also improves quality control and provides data for research.

Computers↗
PubMed1979

A comparison of methods for analysing red cell and platelet volume-distribution curves.

Cell volume-distribution curves may be analysed using log-probability paper or by considering volumes corresponding to frequencies of 50 or 60% of that at the mode. All methods give similar results; the log-probability paper method is better because it allows the researcher to check that the underlying distribution is lognormal; methods based on 50 or 60% modal frequency are slightly less reliable but are simpler for routine use. For platelets it may be convenient to estimate the curve from the modal volume and the volume above the mode at which the frequency is reduced to 60% of the modal frequency.

Animals↗
PubMed1979

Draft protocol for testing calibration and quality control material used with automatic blood-counting apparatus.

A large number of commercial preparations are now available for calibrating or checking the stability of automatic blood counters. Most of these preparations are supplied with 'stated' values though the methods for assigning these values are not described in sufficient detail to allow for an adequate assessment of the validity. The Haemocytometry Panel of the British Committee for Standards in Haematology are therefore proposing a draft protocol for testing calibration and quality control materials. Comments on the draft protocol are invited, either as letters to the Editor of Clinical and Laboratory Haematology or in confidence to the Chairman of the Haemocytometry Panel.

Automation↗