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P Roberts-Thomson

Publications and source records attributed to P Roberts-Thomson.

30 records · Page 2Linked to original sources
PubMed1989

Transesophageal electrocardiography and atrial pacing in acute cardiac care: diagnostic and therapeutic value.

The utility of transesophageal electrocardiography using a bipolar 'pill electrode' was assessed in 17 consecutive patients with tachycardia presenting to our casualty department. Standard 12-lead electrocardiography showed regular narrow QRS tachycardia in 12 patients, and five patients had wide QRS tachycardia. Esophageal atrial electrogram recordings were obtained in 14 patients (82%), and these were helpful in determining the mechanism of tachycardia in 11 patients (78%). Of these 11, seven patients fulfilled criteria for atrioventricular junctional (AVJ) tachycardia based on measurement of the minimum interval between the onset of ventricular depolarisation and earliest atrial (esophageal) activity. One of these patients had presented with a wide QRS tachycardia. The other four patients were diagnosed as having ventricular tachycardia (VT) following diagnosis of AV dissociation. Atrial overdrive pacing, via the pill electrode, successfully reverted four of the nine patients (44%) with narrow QRS tachycardia but no patient with VT. Esophageal recording during tachycardia is a simple, relatively non-invasive technique which is helpful in suggesting the mechanism of tachycardia both in patients with narrow and wide QRS tachycardia, and may have a therapeutic role in patients with AVJ tachycardia.

Adolescent↗
PubMed1986

Low molecular weight IgM. Detection using immunoblotting.

Two techniques for the definitive identification of low molecular weight (LMW) IgM have been compared, namely, filtration chromatography combined with nephelometry and a modified immunoblotting assay. The results indicate that the latter is a more sensitive and reliable technique. Furthermore the resolution of immunoblotting is such that it can distinguish additional oligomeric forms of IgM as well as monomeric IgM suggesting a disorder of polymerization of pentameric IgM. As the presence of LMW IgM in the sera of patients with various disorders is of prognostic significance the immunoblot technique merits consideration as a useful screening assay to detect this moiety.

Arthritis, Rheumatoid↗
PubMed1984

Abnormalities of esophageal and gastric emptying in progressive systemic sclerosis.

Gastric and esophageal emptying were assessed using scintigraphic techniques in 12 patients with progressive systemic sclerosis and 22 normal volunteers. Esophageal emptying was significantly delayed in the patient group, with 7 of the 12 patients beyond the normal range. Gastric emptying was slower in patients than in controls, with 9 patients being outside the normal range for solid emptying and 7 patients outside the normal range for liquid emptying. Findings from gastric and esophageal emptying tests generally correlated well with symptoms of dysphagia and gastroesophageal reflux. However, 2 patients with normal emptying studies had symptomatic heartburn, and 2 patients with delay of both solid and liquid gastric emptying gave no history of gastroesophageal reflux. Delayed gastric emptying may be an important factor in the development of upper gastrointestinal symptoms in patients with progressive systemic sclerosis.

Adult↗
PubMed1979

Inhibition of neutrophil migration by sera from patients with rheumatoid arthritis.

Sera from patients with rheumatoid arthritis inhibited the migration of human neutrophils in 63% (twenty-two out of thirty-five) of the cases tested. The inhibition was not due to a toxic effect of the serum as it was reversed by a chemotactic stimulus. There was a strong correlation between the degree of inhibition of neutrophil migration and the amount of immune complexes present in the sera as determined by the C1q binding activity. It is suggested that the inhibition of neutrophil migration is due to the presence of circulating immune complexes, and that the capacity of immune complexes to inhibit neutrophil migration in vitro may also contribute to the accumulation of neutrophils at sites of immune complex formation in vivo.

Adult↗
PubMed1979

Inhibition of human neutrophil migration by aggregated gammaglobulin.

Heat-aggregated human gammaglobulin has been shown to inhibit the random migration of human neutrophils in serum-containing medium. This inhibition was not due to metabolic exhaustion or deactivation of the cells, since migration in the presence of aggregated gammaglobulin and casein as a chemotactic stimulus was not inhibited. The inhibition of migration was not mediated by a negative chemotactic gradient produced as a result of complement activation, and could be demonstrated in complement-depleted serum. Sera obtained from patients with rheumatoid arthritis with evidence of circulating immune complexes were able to significantly inhibit neutrophil migration, indicating that this phenomenon may be a useful means for the detection of circulating immune complexes. It is suggested that aggregated gammaglobulin or immune complexes can inhibit the chemokinetic effect of serum on neutrophils by a reversible interaction with the neutrophil surface, and that this inhibition could contribute to the accumulation of neutrophils at sites of immune complex deposition in vivo.

Adult↗
PubMedDate not supplied

The in vitro activation of complement by radiologic contrast materials and its inhibition with epsilon-aminocaproic acid.

Radiologic contrast materials activate complement by both the classical and alternative pathways. This activation is time, dose, and temperature dependent and is able to proceed with equal facility in either the presence or absence of Ca++ or Mg++ chelating reagents (EGTA, EDTA). All the components examined (C1, C4, C2, Factor B, C3, and C5) were consumed during complement activation. Immune complexes are produced during interaction of serum with contrast materials. The activation of complement by contrast materials appears to be principally initiated by the activation of plasminogen to plasmin. Inhibition of plasminogen activators by epsilon-aminocaproic acid affects complement activation markedly.

Aminocaproates↗
PubMedDate not supplied

Management of bee-sting anaphylaxis.

A retrospective case analysis of 101 adverse reactions to bee-stings and a prospective questionnaire analysis of the proposed management by local medical practitioners and resident hospital staff members of three hypothetical bee-sting reactions has revealed that understanding of the use of adrenaline in patients with reactions to bee envenomation is confused with regard to the indications for its use, dosage and route; that corticosteroid agents are used or are recommended too frequently, sometimes as the sole therapeutic agent; and that there is a lack of awareness of the need for volume replacement in hypotensive shocked patients. These conclusions highlight the urgent need for a greater understanding of the optimal forms of management for patients with acute anaphylactic reactions to bee envenomation.

Adrenal Cortex Hormones↗
PubMedDate not supplied

Clinical optimization and multicenter validation of antigen-specific cut-off values on the INNO-LIA ANA update for the detection of autoantibodies in connective tissue disorders.

OBJECTIVES: The INNO-LIA ANA Update is a qualitative multiparameter line immunoassay for detection of autoantibodies to several different antigens associated with connective tissue disorders. We sought to optimize and validate the cut-off values for its antigen-specific components: SmB, SmD, RNP-70k, RNP-A, RNP-C, SSA/Ro52, SSA/Ro60, SSB/La, Cenp-B, Topo-I, Jo-1, ribosomal P, and histones. Our aim was to achieve 98% specificity for each of the markers, with respect to differential disease controls, while maintaining sensitivity. METHODS: For optimization, the cut-off value of the different antigen lines was fixed to achieve this specificity using an in-house set of 955 patient samples. Specificity was validated at multiple sites using a different set of 330 samples obtained from 158 apparently healthy blood donors, 100 patients with a variety of infections, 20 each with Wegener's granulomatosis, inflammatory bowel disease, and primary antiphospholipid syndrome, and 12 with psoriatic arthritis. Sensitivity was evaluated, using this optimized cut-off control, in 147 patients with scleroderma, 93 with Sjögren's disease, 40 with systemic lupus erythematosus, 40 with rheumatoid arthritis, 39 with mixed connective tissue disease, and 19 with polymyositis. Sensitivity and specificity of the INNO-LIA ANA Update were determined using the clinical diagnosis as reference. RESULTS: The optimized cut-off values resulted in a specificity 98% or more for all LIA markers except one (histones 97.8%) in the validation set of 330 samples. The sensitivity for each marker tested in 378 samples from the target patient groups was comparable to that reported in the literature. CONCLUSION: The INNO-LIA ANA Update shows uniformly high specificities combined with sensitivities very similar to those of reference assays, in a single test format.

Antigens↗