Search PubMed⌕ Search

Biomedical subjects

D B McClelland

Publications and source records attributed to D B McClelland.

At least 19 recordsLinked to original sources
PubMed1989

Coagulation disorder due to apparent inadvertent heparin administration.

A new competitive binding assay, which measures the concentration of heparin rather than its activity, was used to confirm the presence of a high concentration of heparin in blood samples from a patient which showed unexpected gross prolongation of thrombin time (TT) and activated partial thromboplastin time (APTT). Extrapolation of the heparin concentration enabled estimation of the likely time of administration and the probable dose given. It is possible that an error in dosage may have arisen due to the striking resemblance of vials containing different amounts of heparin marketed by different manufacturers. There is a need for the adoption by manufacturers of a standard coding scheme for vials containing different amounts of heparin (as is adhered to in the case of some drugs, e.g. warfarin), in order to pre-empt this possible source of error.

Adult↗
PubMed1989

Stability of murine monoclonal anti-A, anti-B and anti-A,B ABO grouping reagents and a multi-centre evaluation of their performance in routine use.

We have previously reported the production of 3 murine monoclonal reagents for ABO typing (designated ES-9, ES-4 and ES-15). This study presents results of tests of stability of these 3 reagents, together with a fourth murine monoclonal antibody (LM103/107). In addition, data are also presented from a multi-centre evaluation of the performance of the murine monoclonal reagents in routine ABO typing of both donors and patients using a wide variety of techniques, both manual and automated. The potency and stability of the 4 monoclonal antibody based reagents is compared with a broad selection of monoclonal and polyclonal ABO typing reagents. The reagents used for comparison were produced by European and United States manufacturers in both the public and private sector and are widely used in routine ABO typing. The Scottish monoclonal reagents have been used successfully to ABO type over 500,000 blood samples in 7 centres within the UK, with no discrepant results.

ABO Blood-Group System↗
PubMed1989

Deceptively low morbidity from failure to practice safe blood transfusion: an analysis of serious blood transfusion errors.

Within a 24-month period, 5 patients in a large teaching hospital were mistakenly transfused with blood that had been crossmatched for different patients. Each of the incidents was due to failure by ward staff to adhere to established safely procedures. Three incidents were entirely due to failure to make the standard checks comparing the identity details on the blood pack label with the patient identification details. The fourth incident was due to a combination of inadequate checking and incomplete patient identification procedure. The fifth incident was due to a series of errors that consisted of inadequate checking, plus putting the wrong patient's blood into the sample tube, plus misspelling of the patient's name on both sample tube and request form. There was no serious morbidity. All of these incidents took place when an unusual coincidence or contributing error lead to unmasked inadequate checking of blood unit against patient's identity by ward staff. The incidence of inadequate checking technique may be much higher than the incidence of erroneous transfusion events. It may be difficult to test the ability of an 'improved' transfusion procedure to prevent disasters from erroneous unit-to-patient matching, since assessment will need to include actual 'worst case' situations, which should be rare.

Adolescent↗
PubMed1988

Efficacy of heat treatment of factor VIII concentrate.

Two batches of heat-treated factor VIII concentrate were found to contain anti-HIV-positive plasma donations. The batches were dry-heat-treated at 68 degrees C for 2 and 24 h, respectively. No HIV seroconversions occurred in 13 susceptible haemophiliacs receiving a total of 540 bottles of these factor VIII preparations.

Factor VIII↗
PubMed1988

A fatal transfusion reaction associated with blood contaminated with Pseudomonas fluorescens.

A fatal transfusion reaction due to contamination of platelet-depleted whole blood with Pseudomonas fluorescens is reported. Routine sterility testing on blood products and environmental microbiological monitoring suggested no source for the contaminating organism, as has been the case for the majority of reported incidents of this type. The value of routine sterility testing in the prevention and investigation of such incidents is discussed.

Aged↗
PubMed1988

Tolerance of Scottish National Blood Transfusion Service intravenous immunoglobulin in patients with primary hypogammaglobulinaemia: report of 1235 infusions.

A total of 1235 immunoglobulin infusions were carried out as replacement therapy in 37 patients suffering from primary hypogammaglobulinaemia from 1983 to 1987, using Scottish National Blood Transfusion Service (SNBTS) IV IgG, manufactured by cold ethanol fractionation of plasma, ultrafiltration and mild pepsin proteolysis at pH4. Ten patients experienced adverse reactions during 34 infusions (2.8% of all infusions) and all but five were mild; 21 (62%) of the adverse reactions were encountered in the patients' first five infusions. A maximum immunoglobulin infusion rate of 5 mg/kg/min was tolerated without adverse reaction.

Adolescent↗
PubMed1987

Double-blind comparative trial of standard (commercial) and antibody-affinity-purified tetanus toxoid vaccines.

Tetanus toxoid purified by antibody-affinity chromatography, was compared with conventionally purified material in a double-blind trial in 205 healthy blood donors. There was neither any difference in immunogenicity as assessed by enzyme-linked immunoassay nor in side-reactions between the two vaccines. This study confirms that side-reactions to tetanus toxoid are not eliminated by purifying it.

Adolescent↗
PubMed1987

Assessment of a new centrifugal plasmapheresis machine: the SPC-600.

An approach to the full assessment of new plasmapheresis machines is outlined. This involves testing for changes in donated blood, donors and blood components using fresh donor blood and during full procedures in an animal model prior to performing full procedures in human volunteers. Using this approach, a new centrifugal plasmapheresis machine, the SPC-600, was assessed. No adverse effects associated with the use of the machine were detected in the initial studies. When used for plasmapheresis of volunteers, 500 ml of plasma was obtained in 43 +/- 4 min without adverse effects on donors. The plasma product contained normal levels of plasma proteins, including factor VIII, and 20 +/- 6 X 10(9)/1 platelets. There was no evidence of activation of complement or coagulation systems, and the factor VIII yield in cryoprecipitate prepared from single donations of plasma was equivalent to that observed for standard whole blood donations.

Animals↗
PubMed1986

Measurement of human and mouse anti-tetanus antibodies and isotype analysis by ELISA.

A rapid and sensitive enzyme immunoassay (ELISA) was developed for the quantitation of anti-tetanus antibodies. This technique was used to measure antibody levels in the plasma of immunized donors, in human anti-tetanus IgG preparations and in human and mouse hybridomas producing monoclonal antibodies to tetanus toxoid. The assay was capable of detecting antibody levels as low as 5 X 10(-4) IU/ml. By inclusion of an extra step involving antibodies to mouse Ig isotypes, a sandwich enzyme immunoassay (SEI) was developed which permitted determination of the Ig isotype of mouse anti-tetanus antibodies including tetanus-specific mouse monoclonal antibodies. SEI confirmed Protein A-Sepharose fractionation of mouse ascites fluid containing anti-tetanus antibody. The tetanus toxoid-coated plates have a shelf life of at least 1 year.

Animals↗
PubMed1986

An evaluation of the safety of three intravenous immunoglobulin preparations in patients with primary hypogammaglobulinaemia.

In an open study, three different immunoglobulin preparations for intravenous use (IV IgG), namely pH4 and pepsin treated immunoglobulin ('Sandoglobulin'); reduced and alkylated immunoglobulin ('Gamimune') as well as ultrafiltered, pH4 and pepsin treated immunoglobulin manufactured by the Scottish National Blood Transfusion Service ('SNBTS IV IgG'), were compared with intramuscular immunoglobulin (IM IgG) in five patients with primary hypogammaglobulinaemia, by treating each patient consecutively with each immunoglobulin preparation for 3 months. Few adverse reactions were noted with any of the intravenous immunoglobulin preparations and these mainly consisted of mild fever (less than 38 degrees C). Concentrations of serum IgG were higher with all intravenous immunoglobulin preparations compared with IM IgG. Furthermore, all the patients preferred IV to IM IgG therapy. As higher doses of immunoglobulin are associated with a reduction in infections in hypogammaglobulinaemic patients, we conclude that intravenous immunoglobulin therapy should be considered for the prophylaxis of infection in patients with primary hypogammaglobulinaemia.

Agammaglobulinemia↗