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Biomedical subjects

P Atkinson

Publications and source records attributed to P Atkinson.

At least 55 records · Page 3Linked to original sources
PubMed1992

Skin lesion removal: practice by general practitioners in Grampian Region before and after April 1990.

The introduction of new GP contracts in April 1990 incorporated a financial incentive to undertake minor surgical procedures. Previous reports have noted large increases in the number of GP-derived skin specimens after April 1990. Our present study intended to address whether similar changes have occurred in Grampian Region as well as, more specifically, noting whether there have been changes in the quality of practice following the 1st April 1990. A retrospective study of skin biopsies removed by general practitioners in Grampian Region was undertaken. Cases were selected from four periods of six months (1st April to end of September) in 1987, 1988, 1989 and 1990. All skin specimens sent by general practitioners to the Department of Pathology, Aberdeen Royal Infirmary, were included. Following April 1990 there was a two-fold increase in skin specimen numbers--an increase significantly greater than increases observed over previous years (p < 0.01). Of particular note was the contribution made to this increase by Aberdeen City GPs whose contribution rose five-fold (p < 0.0001). Non-benign lesions (ie malignant plus carcinoma-in-situ-) represented 6% of lesions excised. A non-benign clinical diagnosis or an indication of suspicion was written on only one third of request forms for histopathologically diagnosed non-benign lesions. The proportion of histologically incompletely excised lesions rose over the four years (p < 0.01); moreover the increase in total numbers of lesions resulted in a striking increase in the actual numbers of incompletely excised lesions after April 1990.

Biopsy↗
PubMed1991

Students of midwifery: 'doing the obs' and other coping strategies.

The paper is based on qualitative research on the early experiences of student midwives in one school of midwifery. During their initial encounters the students go through a status passage from experienced nurse to novice midwife. Student diaries and ethnographic data were used to explore how students manage the transition and to document their coping strategies. In particular it is shown how, in response to the uncertainties of their new status, student midwives may revert to routinised nursing activities.

Adaptation, Psychological↗
PubMed1990

Behavioural and epidemiological considerations pertaining to necrotic araneism in southern Africa.

Species of three spider genera are known to cause dermonecrotic lesions in man. The incidence of necrotic araneism caused by species of these genera is a function of their behaviour and their geographical distribution in relation to areas of high human population density. Evidence based on an analysis of 39 diagnosed spider bites suggests that sac spiders (Chiracanthium sp.) are responsible for most spider bites, followed by violin spiders, Loxosceles sp.

Africa, Southern↗
PubMed1990

A key for the clinical diagnosis of araneism in Africa south of the equator.

A simple key that will enable the clinician to diagnose the culprit species in cases of spider bite in Africa south of the equator in the absence of the culprit is presented. Species of four spider genera are responsible for virtually all the cases of araneism requiring medical attention, viz. Latrodectus, Chiracanthium, Loxosceles and Sicarius. The signs and symptoms at various intervals following envenomation by these spiders are sufficiently distinctive to allow specific diagnosis in most cases. To make this more easily possible the signs and symptoms at various intervals after envenomation have been tabulated in the form of a diagnostic key.

Africa, Southern↗
PubMed1989

Calcium-dependent activation of human neutrophils by a synthetic ionophore.

Synthetic block copolymers composed of polyoxyethylene and poly-oxypropylene have been demonstrated to possess ionophore activity selective for monovalent cations and to cause histamine release from mouse mast cells and human basophils. We now report calcium-dependent release of granule contents from human neutrophils by the most active of these agents, TI30R2. At a concentration of 100 micrograms/ml (12.5 microM), net lysozyme release ranged from 17-40% after 30 minutes incubation at 37 degrees. Lysozyme release was dose-dependent over stimulus concentrations of 5-50 micrograms/ml (0.625-6.25 microM). Release was dependent upon the presence of extracellular calcium. T130R2 did not induce the release of superoxide anions over 30 minutes of incubation. As T130R2 induces sodium influx into cells, it is likely that a depolarizing influx of sodium ions in the presence of extracellular calcium constitutes a sufficient signal for granule release but not superoxide production by human neutrophils.

Calcium↗
PubMed1989

Platelet aggregability in sleep-related stroke.

We examined platelet aggregability during nocturnal sleep and daytime wakefulness in patients with a history of sleep-related stroke onset (SOS) and compared it to that of matched awake-onset stroke (AOS) patients and controls without evidence of vascular disease. Aggregability was evaluated in-vitro at least seven weeks following stroke onset. Platelets were more aggregable to ADP, collagen and arachidonic acid (AA) during both sleep and wakefulness in patients with AOS (p less than 0.01). No significant difference in the mean aggregation thresholds during sleeping or waking periods were found between SOS and control groups. However, platelets were significantly more responsive to AA during sleep than during wakefulness in the SOS patients (p less than 0.01). This difference was confined to the subgroup of SOS patients who had experienced nocturnal as opposed to daytime sleep-related stroke onset, suggesting that the observed difference in platelet responsiveness to AA may be related to a circadian fluctuation in platelet aggregability rather than to a sleep-related fluctuation. Significant sleep-related changes in platelet aggregability were not identified in the other two groups.

Adenosine Diphosphate↗
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↗