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Biomedical subjects

A Jones

Publications and source records attributed to A Jones.

At least 505 records · Page 28Linked to original sources
PubMed1990

The effect of symptom presentation on delay in asthma diagnosis in children in a general practice.

Analysis of 187 children diagnosed as having asthma since 1984 in a general practice population is described. Reasons were sought for possible delay in diagnosis so that appropriate steps could subsequently be taken to minimize further delay. Even in an asthma aware practice (original prevalence 8.8%) a delay of approximately 40% of the total age of the child at diagnosis is shown. This delay does not appear to diminish even for children up to 10 years of age. Asthma is more likely to be missed or labelled as 'bronchitis' in children who cough repeatedly, rather than those who wheeze occasionally. As many as 45% of asthmatic children may have had 'bronchitis' diagnosed and treated instead of asthma, so that a diagnosis of repeated 'bronchitis' merely detracts from underlying asthma.

Asthma↗
PubMed1990

Radiotherapy for stage I Hodgkin's disease: 20 years experience at St Bartholomew's Hospital.

One hundred and one consecutive patients with newly diagnosed stage I Hodgkin's disease (HD) received treatment at St Bartholomew's Hospital, between 1968 and 1987, with a median follow-up of 12 years. Eleven patients have been excluded from detailed analysis because they either received involved field radiotherapy (RT) or radiotherapy with chemotherapy or were lost to follow-up. Actuarial analysis predicts 78% to be alive and without relapse of Hodgkin's disease at 15 years. Ninety evaluable patients (clinical stage (CS) 24; pathological stage (PS) 66) received either mantle or inverted 'Y' RT and form the basis of this analysis. The median age was 33 years (63 men, 27 women). Histology at presentation was nodular sclerosing (39), lymphocytic predominant (27) or mixed cellularity (24). The presenting site was neck (78), axilla (6) groin (4) and mediastinum (2). Complete remission was achieved in all evaluable patients, the actuarial proportion in remission being 75% at 15 years. Factors predictive of a prolonged remission were pathological staging versus clinical staging (P = 0.02) and lymph node size less than 3 cm (P = 0.04). Actuarial overall survival in these 90 patients was 75% at 15 years and none of the above factors correlated with survival. Relapse of HD has occurred in 18 patients (5 within RT field, 10 without and 3 in both). Second remission was achieved in 15/18. The actuarial rate of second remission and survival was 40% at 10 years. Sixteen patients have died, 7 of Hodgkin's disease, 7 of unrelated causes and 2 of second malignancy. A further 3 patients who developed second malignancy are still alive. At 15 years the actuarial mortality related to HD was 12%. These results confirm the importance of long follow up to assess the efficacy of primary therapy.

Adolescent↗
PubMed1990

Quantitative assessment of full range-of-motion isometric lumbar extension strength.

The purpose of this study was to evaluate the reliability and variability of repeated measurements of isometric (IM) lumbar extension (LB EXT) strength made at different joint angles. Fifty-six men (age, 29.4 +/- 10.7 years) and 80 women (age, 24.3 +/- 9.1 years) completed IM LB EXT strength tests on 3 separate days (D1, D2, and D3). On D1 and D2, subjects completed two tests (T1 and T2) separated by a 20- to 30-minute rest interval. For each test, IM LB EXT strength was measured at 72, 60, 48, 36, 24, 12, and 0 degrees of lumbar extension. Mean IM strength values, within-day reliability coefficients, and test variability over the seven angles improved from D1 to D2 (D1: mean, 160.0 to 304.1 N.m, r = 0.78 to 0.96, SEE = 37.6 to 46.9 N.m; D2: mean, 176.3 to 329.1 N.m, r = 0.94 to 0.98, SEE = 29.0 to 34.4 N.m). Mean strength values leveled off by D3 (174.5 to 317.0 N.m). The most reliable test results showed that the IM LB EXT strength curves were linear and descending from flexion to extension and ranged from 235.8 +/- 85.2 to 464.9 +/- 150.7 N.m for men (extension to flexion) and from 134.6 +/- 53.2 to 237.3 +/- 71.9 N.m for women. Lumbar extension strength was clearly greatest in full flexion, which is in contrast to previously reported results. One practice test was required to attain the most accurate and reliable results. These data indicate that repeated measures of IM LB EXT strength are highly reliable and can be used for the quantification of IM LB EXT strength through a range of motion.

Adult↗
PubMed1990

Effect of training frequency and specificity on isometric lumbar extension strength.

To investigate the effects of training frequency and specificity of training on isolated lumbar extension strength, 72 men (age = 31 +/- 9 years) and 42 women (age = 28 +/- 9 years) were tested before and after 12 weeks of training. Each test involved the measurement of maximum voluntary isometric torque at 72 degrees, 60 degrees, 48 degrees, 36 degrees, 24 degrees, 12 degrees, and 0 degrees of lumbar flexion. After the pretraining tests, subjects were randomly stratified to groups that trained with variable resistance dynamic exercise every other week (1X/2 weeks, n = 19), once per week (1X/week, n = 22), twice per week (2X/week, n = 23) or three times per week (3X/week, n = 21); a group that trained isometrically once per week (n = 14); or a control group that did not train (n = 15). Analysis of covariance showed that all training groups improved their ability to generate isometric torque at each angle measured when compared with controls (P less than 0.05). There was no statistical difference in adjusted posttraining isometric torques among the groups that trained (P greater than 0.05), but dynamic training weight increased to a lesser extent (P less than 0.08) for the 1X/2 weeks group (26.6%) than for the groups that trained 1X/week, 2X/week, and 3X/week (37.2 to 41.4%). These data indicate that a training frequency as low as 1X/week provides an effective training stimulus for the development of lumbar extension strength. Improvements in strength noted after isometric training suggest that isometric exercise provides an effective alternative for developing lumbar strength.

Adult↗
PubMed1990

Selective beta-adrenoceptor partial agonist effects of pindolol and xamoterol on skeletal muscle assessed by plasma creatine kinase changes in healthy subjects.

1. The effects of selective beta-adrenoceptor partial agonist activity on plasma creatine kinase (CK) and skeletal muscle symptoms were studied in normal volunteers. 2. A drug with beta 1-selective partial agonist activity (xamoterol) and one with partial agonist activity acting mainly through beta 2-adrenoceptors (pindolol) were each given for 3 weeks in a randomised double-blind crossover study in 10 subjects. Five additional subjects received only one drug. Plasma CK levels were monitored during a baseline placebo run-in phase, the active treatment period and a placebo washout phase which continued until CK levels returned to baseline. 3. The degree of beta-adrenoceptor antagonism was determined by the inhibition of exercise-induced tachycardia and was similar for the two drug doses used. 4. During pindolol administration plasma CK levels rose compared with pretreatment baseline levels and with levels during xamoterol administration which did not rise. After pindolol was withdrawn CK levels reached higher peaks in some subjects after 1-5 days. 5. Muscle cramps were reported by five subjects during pindolol administration and by one of these subjects but to a lesser extent during xamoterol administration. 6. Pindolol may produce this effect, which was not seen with xamoterol, because of its specific beta 2-adrenoceptor partial agonist activity. Elevations in plasma CK produced by this type of drug or its withdrawal may cause confusion in the diagnosis of muscle disease or myocardial infarction unless the myocardial isoenzyme is measured.

Adrenergic beta-Agonists↗
PubMed1990

Production of cyclosporins by Tolypocladium niveum strains.

Nine strains of Tolypocladium niveum (= inflatum) were compared for their production of cyclosporins. Two of the strains, which were originally from the parental NRRL 8044 strain, were among the lower producers, while seventeen Tolypocladium strains belonging to seven other species produced no detectable cyclosporins. Variable cyclosporin production was observed initially. Once extraction and quantitation methods had been established, spore inoculum density and cultural morphology and carbon and nitrogen sources were found to be among the variables affecting cyclosporin production. Cyclosporin A was identified by cochromatography by using high-performance liquid chromatography, and cyclosporins A, B, and C were identified by gas chromatography-mass spectroscopy; all three compounds exhibited biological activity. They were routinely produced as a mixture in the ratio 7:1:2 in T. niveum UAMH 2472, which was selected on the basis of single-spore isolate total cyclosporin production and was used for most studies. This strain routinely produced total cyclosporin levels of 150 to 200 mg.liter-1 after 12 days of growth on a 2% sorbose-1% vitamin assay Casamino Acids medium.

Culture Media↗
PubMed1990

Septic arthritis complicating apatite associated destructive arthropathy.

Septic arthritis can complicate many forms of arthritis. Two cases of apatite associated destructive arthropathy (AADA) complicated by sepsis are described. Diagnosis of this complication in the setting of severe joint damage is difficult as AADA and sepsis share certain characteristics--an initial, rapidly progressive, severely painful course and radiographs which show rapidly destructive changes with marked cartilage loss, bone attrition, and virtual absence of osteophyte or cyst response.

Aged↗
PubMed1990

Magnetic resonance imaging, computed tomography and endosonography in the local staging of carcinoma of the cervix.

Thirty-seven patients with carcinoma of the cervix were prospectively staged by examination under anaesthesia (EUA), transvaginal and transrectal ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI). Pathological correlation was available for 20 patients. In the pathologically staged patients, EUA agreed with the staging in 17, understaging three patients. Endosonography agreed with the staging in 19, CT in 16 and MRI in 18 patients. For the remaining 17 patients, endosonography agreed with the EUA findings in 13, CT in 12 and MRI in 12. This study has shown that endosonography and MRI are more accurate than CT in the local staging of carcinoma of the cervix. Computed tomography was least accurate in staging early tumours and differentiating between Stage Ib and IIb disease. Lymph node involvement was detected with equal frequency by both CT and MRI. Magnetic resonance imaging was useful in identifying vaginal and bladder wall involvement and in one patient showed features due to an unsuspected early pregnancy.

Adult↗
PubMed1990

Comparison of flow cytometry and retrospectively applied static cytometry on lymphoid tissue.

Twenty cases of non-Hodgkin's malignant lymphoma were examined using both flow cytometry (FCM) and static cytometry (SCM) DNA analysis to detect aneuploidic cell populations. FCM was performed on fresh cell suspensions whilst SCM was performed retrospectively on formalin-fixed, paraffin-embedded samples of the same tissue. A total of 34 aneuploidic cell lines were detected by FCM compared to a total of 41 detected by SCM. Of the 20 cases 14 showed DNA indexes within 10% of each other for each method, indicating a reasonable degree of comparability between the two methods. Of the 6 cases which did not show comparable DNA indexes, 2 displayed similar cell lines for both methods, but the major abnormal cell populations were of different ploidy by SCM as compared to FCM. A qualitative comparison is thus possible between these two cases. The results suggest that retrospectively applied SCM ploidy analysis of lymphoid tissue is comparable to FCM on fresh tissue samples and can thus be used in retrospective studies of both prognostic and diagnostic significance.

Cytological Techniques↗
PubMed1990

Thrombin and factor Xa enhance the production of interleukin-1.

Interleukin-1 (IL-1) plays a major role in inflammatory responses. Activation of coagulation and fibrin deposition typical of these reactions is mediated by macrophage procoagulants induced on stimulated macrophages. IL-1 activity in the supernatant of lipopolysaccharide (LPS)-stimulated guinea-pig macrophages was markedly enhanced by the presence of thrombin during macrophage activation. Although thrombin alone had no effect, inclusion of 1 mU/ml of thrombin with suboptimal levels of LPS produced a 200-fold increase in IL-1 activity, and further enhancement was observed with increasing doses of thrombin. The active site of thrombin was necessary for enhancement, as the serine esterase inhibitor di-isopropyl-fluorophosphate (DIP) and hirudin inhibited the synergy observed with LPS and thrombin. Prothrombin and Factor Xa also enhanced IL-1 production, although not to the same extent as thrombin. Factor Xa-like activity was demonstrated on the surface of LPS-stimulated macrophages. Both the Xa-like activity and IL-1 generated by LPS-stimulated cells were inhibited by heparin. Heparin with a high affinity for antithrombin III (anti-coagulant heparin; HAH) inhibited IL-1 generation, whereas low-affinity heparin (non-anticoagulant; LAH) had no effect. We show that proteases of the extrinsic coagulation cascade enhance IL-1 generation and propose that a Factor Xa-like activity present in activated macrophages, together with thrombin, may be important in IL-1 processing.

Animals↗
PubMed1989

Effects of recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) on single CD34-positive hemopoietic progenitors from human bone marrow.

To determine the extent accessory cells mediate the effects of recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) on human hemopoietic progenitors in vitro, we added this hemopoietin to liquid cultures of single CD34-positive marrow cells. These were selected on a fluorescence-activated cell sorter using the HPCA-1 (My10) antibody. Myeloid, erythroid and a few mixed clones developed in 13% of wells in the apparent absence of accessory cells at the beginning of culture. Although accessory cells were generated quickly from the myeloid progenitors and could have mediated the action of rhGM-CSF, this was not the case in the majority of the erythroid clones in which no other cell types were recorded. We conclude that rhGM-CSF can act directly on a subset of erythroid progenitors and probably induces a substantial number of myeloid clones directly.

Bone Marrow↗