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Biomedical subjects

P Atkinson

Publications and source records attributed to P Atkinson.

At least 37 records · Page 2Linked to original sources
PubMed1988

Review of southern African spiders of medical importance, with notes on the signs and symptoms of envenomation.

Medically important spiders in southern Africa are discussed in terms of their morphological features and distribution, the signs and symptoms of envenomation and the possible treatment thereof. A simple pictorial key is provided to enable the non-specialist to identify the neurotoxic and cytotoxic species. The following spiders are now known to be medically important in southern Africa: Latrodectus indistinctus (neurotoxic), Chiracanthium lawrencei (cytotoxic), Loxosceles sp. (cytotoxic) and Sicarius sp. (cytotoxic - haemotoxic).

Animals↗
PubMed1988

Platelet parameters. Part I. Platelet counts and mean platelet volume in normal and pregnant subjects.

Platelet counts and mean platelet volume (MPV) were studied in 564 normal subjects and 297 pregnant women using a Coulter Model S-Plus electronic counter. The reproducibility of these measurements both intra- and inter-sample was documented. The mean platelet count in the normal group was 283 x 10(9)/l while the mean MPV was 9.32 fl. An inverse correlation between platelet volume and platelet number was documented (r = -0.38; P less than 0.0001). By interval analysis, this inverse relationship was shown to be non-linear. In the pregnant subjects there appeared to be a progressive decrease in platelet count with advancing gestation; this reached a significant level when the first and third trimesters were compared with each other (P less than 0.05). The MPV was unchanged. The fact that the platelet count decreased in proportion to the red cell count suggested that a common factor, such as haemodilution, was in part responsible. There was again an inverse relationship between MPV and platelet number (r = -0.39; P less than 0.0001) shown to be non-linear by interval analysis.

Blood Platelets↗
PubMed1988

Platelet parameters. Part II. Platelet volume-number relationships in various normal and disease states.

The relationship between mean platelet volume (MPV) and platelet count was evaluated in 259 patients with rheumatoid arthritis and 311 patients with various haematological disorders. Platelet volume-number relationships determined in a previous study on normal subjects were used as a reference range. There was a significant inverse relationship between MPV and platelet count in patients with rheumatoid arthritis (r = -0.49; P less than 0.0001), which by interval analysis was shown to be non-linear. In the patients with haematological disorders, the platelets were found to be disproportionately small for number in patients with aplastic anaemia, chemotherapy-induced marrow suppression and some cases of acute idiopathic thrombocytopenic purpura (ITP). In subjects with chronic ITP followed longitudinally, the inverse platelet volume-number relationship was retained. MPV was appropriate for platelet number in myelodysplastic syndromes, variable in iron deficiency anaemia and disproportionately large in myeloproliferative syndromes, most notably in agnogenic myeloid metaplasia. The observation that the MPV was disproportionately large in comparison with the platelet count was used in establishing the diagnosis of an hereditary giant platelet syndrome in a family of British origin.

Adult↗
PubMed1988

Use of cyclic antidepressants in patients with cardiac conduction disturbances.

Cyclic antidepressants can produce cardiac complications in patients with certain types of cardiac conduction abnormalities. Most cyclic antidepressants have a quinidinelike effect on the heart, which, in combination with Type I antiarrhythmic agents such as quinidine, disopyramide and procainamide, may induce heart block and potentially lethal arrhythmias in susceptible individuals. Patients with known cardiovascular disease warrant careful evaluation before tricyclic therapy is initiated. Guidelines are presented for identifying high-risk patients and for using cyclic antidepressants in patients with cardiac conduction abnormalities.

Antidepressive Agents↗
PubMed1988

Plasma leukotriene C4 and reactions to contrast media.

Forty-five patients were randomly divided into three groups of 15 and within each group patients were given iothalamate, iopamidol or ioxaglate intravenously during radiological investigations. The plasma leukotriene C4 level was measured before and 30 s and 3 min after the administration of the respective contrast media. In patients demonstrating non-idiosyncratic contrast reactions, a consistent decrease in plasma leukotriene concentration was noted at both 30 s and 3 min following the administration of all three contrast media. A statistically significant decrease in plasma leukotriene occurred at 30 s with ioxaglate, but not with the other two agents. In the limited number of patients who experienced idiosyncratic reactions, the decrease in plasma leukotriene concentration was less apparent. This decrease in plasma leukotriene concentration has been attributed to changes in plasma volume following administration of hyperosmolar contrast media. The inability to demonstrate an increase in plasma leukotriene levels following the administration of both conventional and new, low-osmolar radiographic contrast media supports the cumulative evidence against an allergic mechanism in the majority of non-idiosyncratic and some idiosyncratic contrast reactions.

Female↗
PubMed1987

Hematologic and iron-related measurements in rheumatoid arthritis.

The hematologic status of 265 patients with rheumatoid arthritis was assessed. In the group as a whole, a mild depression in the hemoglobin concentration and mean cell volume (MCV) was associated with an increase in the red blood cell distribution width (RDW), erythrocyte sedimentation rate (ESR), and platelet count. Bone marrow trephine biopsies and further measurements of iron status and disease activity were done in [a further] 38 more anemic patients, and the findings in those with absent marrow iron (iron deficiency) were compared with those having stainable stores (anemia of chronic disorders). The RDW was raised in both, and there was no significant difference between the two groups. The concentrations of nonheme iron in the marrow and of serum ferritin were significantly lower in the iron-deficient group, but the geometric mean serum ferritin of 34 micrograms/L was still a good deal higher than that associated with uncomplicated iron deficiency. This was presumably because of the fact that the serum ferritin, which was significantly correlated with the ESR (r 0.55; P less than 0.0004) and C-reactive protein (CRP) r 0.41; P less than 0.01), was also functioning as an acute phase protein. While there was a weak correlation (r 0.37; P less than 0.04) between the marrow nonheme iron and the serum ferritin concentrations, it disappeared when nonactive patients with normal CRP concentrations were excluded. The absence of a correlation is unlike the findings that have previously been noted in other chronic inflammatory conditions and in neoplasia. This raises the possibility that serum ferritin concentrations in rheumatoid arthritis may reflect, in part at least, another store of iron located in affected joints.

Anemia↗
PubMed1987

Reactive thrombocytosis in pulmonary tuberculosis.

The incidence of reactive thrombocytosis in active pulmonary tuberculosis was studied in 122 patients. Thrombocytosis was common, platelet counts often exceeding 1 X 10(12)/1. A significant inverse correlation was noted between the mean platelet volume and the platelet count (r = -0.54, p less than 0.0001). Interval estimation suggested that this relation was non-linear. Further studies were done in a small group of six patients. Platelet survival was considerably shortened, the platelets aggregated excessively in vitro, serum concentrations of thrombopoiesis stimulating activity were raised, and serotonin uptake and release were within normal limits. The degree of thrombocytosis correlated significantly with the degree of inflammation measured by the erythrocyte sedimentation rate (r = 0.40, p less than 0.003) and serum C-reactive protein concentration (r = 0.35, p less than 0.008).

Arachidonic Acids↗
PubMed1986

Red blood cell distribution width in the anemia secondary to tuberculosis.

A study was done to explore the claim that anisocytosis as measured by the red blood cell volume distribution width (RDW) is raised in iron-deficiency anemia, but is normal in the anemia of chronic disorders. Measurements were done on 283 normal patients, 22 iron-deficient patients, and 102 tuberculotic patients, using a model S plus Coulter Electronic Counter with standard calibration. Mean (+/- SD) values for RDW were as follows: normals, 7.36 (+/- 0.57); untreated iron deficiency, 10.39 (+/- 1.37); and 15 untreated anemic patients with tuberculosis, 10.44 (+/- 0.63). Mean values remained above 10.4 in 69 patients with tuberculosis during treatment, irrespective of whether or not the patients were anemic, but had fallen towards the normal mean (8.49 +/- 0.8) in the 18 subjects in whom it was measured at the end of therapy. By this time the mean corpuscular volume (MCV) and hemoglobin concentrations had risen to normal. It is concluded that RDW values in the chronic inflammatory disorder tuberculosis are not significantly different from those occurring in iron-deficiency anemia.

Anemia↗
PubMed1986

Haematological and iron-related measurements in active pulmonary tuberculosis.

59 patients with active pulmonary tuberculosis were evaluated in terms of haematological indices, iron-related measurements and markers of inflammation. The variables evaluated included the Hb, mean cell volume (MCV), serum iron, total iron-binding capacity, percentage saturation, serum ferritin, erythrocyte sedimentation rate (ESR) and C-reactive protein. In addition, marrow iron stores were assessed both histologically and chemically. Among the changes noted was a raised S-Ferritin, which appeared in part to be a component of the acute phase response, since it correlated with C-reactive protein concentration (r 0.59, p less than 0.0001). In addition, there was a good correlation between the S-Ferritin and the concentrations of non-haem iron in the marrow, as assessed chemically on trephine biopsies (r 0.78, p less than 0.0001) and histologically on aspirated and biopsy material (rS 0.78, p less than 0.0001 and rS 0.68, p less than 0.0001, respectively). Furthermore, the quantitative relationship between the S-Ferritin and the chemical concentrations of non-haem iron in the marrow was similar to that found previously in a heterogeneous group of subjects without infections. While the present findings confirm that iron is diverted into reticuloendothelial stores in active pulmonary tuberculosis, no evidence was found to suggest that the anaemia which was present in 45 of the 59 patients was secondary to iron-deficient erythropoiesis; the percentage saturations in the 2 groups were 30.3 and 31.1 respectively. In a final analysis, the present findings were compared with previous ones obtained in a group of patients with Hodgkin's disease. The degree of rise in the S-Ferritin for a given marrow non-haem iron concentration was significantly less in the patients with tuberculosis (p less than 0.0001).

Adult↗
PubMed1985

Direct measurement of antibody production in cell suspensions using an enzyme-linked immunosorbent assay.

We have developed an enzyme-linked immunosorbent assay (ELISA) to measure antibody production in cell suspensions using highly sensitive avidin-biotinylated peroxidase (ABC) reagents. The cells are serially diluted in media and placed directly on a standard antigen-coated microtiter plate for 6 h, and the plate is then washed and processed to determine the bound antibody. The amount of antibody detected is reduced by puromycin indicating in vitro synthesis. Standard errors of the means of optical density readings of replicate samples are less than 10%. The background readings and readings obtained using non-immune cells are negligible, demonstrating no significant contamination by endogenous peroxidases.

Animals↗
PubMed1984

Training for certainty.

This paper offers a critique of the idea of 'uncertainty' in the sociology of medicine, particularly in the context of studies of medical education. The work of Renée Fox is used as the main example of the work against which this criticism is levelled. It is argued that the idea of 'training for uncertainty' has been over-emphasized in previous literature. The notion of 'training for certainty' is proposed as a corrective. Finally, however, it is argued that an adequate phenomenology of medical knowledge, education and practice must recognize 'certainty' and 'uncertainty' as two different 'attitudes', which may co-exist simultaneously, reflecting different practical and theoretical interests.

Attitude of Health Personnel↗
PubMed1979

Doppler ultrasound examination of pathologically enlarged lymph nodes.

Pathologically enlarged lymph nodes have been examined with a commercially available 10 MHz continuous-wave Doppler flowmeter. Many enlarged lymph nodes gave rise to significant Doppler-shift signals indicating increased blood flow. The signals have been spectrum analysed and the large diastolic flow components suggest that there is considerable arterio-venous shunting within lymph glands involved in leukemia, lymphoma and carcinoma. It also seems that the signals tend to diminish in response to treatment. The Doppler signals have been used in an imaging system to produce a vascular map of the region of the enlarged gland. It is suggested that these findings might be applicable to the detection of neoplastic tissues in less accessible sites.

Doppler Effect↗