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Biomedical subjects

B Jones

Publications and source records attributed to B Jones.

At least 37 records · Page 2Linked to original sources
PubMed2005

Unnecessary repeat requesting of tests: an audit in a government hospital immunology laboratory.

Unnecessary repeat requesting of tests can make up a large proportion of a laboratory's workload. This audit set out to establish the size of this problem and to identify the circumstances under which these repeat requests were made in a government tertiary hospital immunology laboratory. The numbers of tests for immunoglobulin measurement, common autoantibodies, and tumour markers that were repeated over a 12 month period were analysed by interrogating the Delphic laboratory computer system using a management information system for raw data enquiry protocol. Repeat requests within 12 weeks of a previous request made up 16.78% of the total workload. The total cost of the tests was estimated at 132 151 US dollars. The waste of technician time and reagents as a result of unnecessary repeat testing is excessive. Many of these tests might be eliminated with the use of interventions such as computerised reminders.

Autoantibodies↗
PubMed2005

Modelling the expected increase in demand for particle radiotherapy: implications for the UK.

The present rapid worldwide expansion of particle radiotherapy services will inevitably have an impact on clinical practice within the UK. The most recent results of developmental trials using protons and carbon ions are impressive, with high cure rates and little or no functional normal tissue changes and a very low level of serious treatment-related morbidity. The potential numbers of patients that will demand or are referred for treatment abroad are estimated, assuming different rates of change and treatment capacities with time. Even if the maximum demand were to be under 10% of all patients presently treated by radiotherapy, significant numbers (amounting to several thousand patients per year) may be advised to seek treatment abroad between 5 and 10 years from now. The gap between overall demand and the estimated numbers could be partly, although substantially, filled by the establishment of a single large UK facility. Should demand increase beyond the estimated level, for example due to improved screening of cancer, then a network of UK particle radiotherapy centres will be required.

Humans↗
PubMed2005

The potential for mathematical modelling in the assessment of the radiation dose equivalent of cytotoxic chemotherapy given concomitantly with radiotherapy.

The linear quadratic (LQ) concept of biological effective dose (BED) is used with Poisson statistics to estimate the radiation equivalent BED of cytotoxic chemotherapy (CBED) that would provide improvements in tumour control probability (TCP) typically achieved in randomized clinical trials of chemoradiation. The concepts of pure radio-sensitization and independent chemotherapy cell kill are represented by mathematical equations. Small values of sensitizer enhancement ratios (s) can provide modest increases in TCP when large numbers of radiotherapy fractions are sensitized; larger s values are required if only a small number of radiotherapy fractions are sensitized. Independent chemotherapy induced cell kill is sufficient to explain the benefits achieved with concomitant chemoradiotherapy in situations where a sufficiently high chemotherapy dose intensity is used (i.e. the dose-time intensity of cytotoxic chemotherapy without radiation is considered to be sufficient to cause significant tumour regression although not cure). Care is required in the use of the Poisson cure probability model because of the associated steep dose-response curves that may underestimate both s and the CBED. By use of random sampling methods and estimation over a theoretical population of different tumours, more robust results are obtained with dose-response curves that correspond better to those in clinical data sets. These predict a 2-4 Gy(10) equivalent for each pulse of chemotherapy such as single agent Cis-Platinum when used weekly during radiotherapy for a maximum of 4 cycles. This preliminary paper does not consider normal tissue complication probabilities, of which there are relatively few mature results for modern chemoradiotherapy. The BED concept can be used to estimate the equivalent dose of radiotherapy that will achieve the same cell kill as concomitant cytotoxic chemotherapy. Relatively simple radiobiological modelling can be used to guide decision-making regarding the assessment of the most appropriate combined modality schedules, and has important implications in the design of clinical trials.

Antineoplastic Agents↗
PubMed2004

Use of neoadjuvant chemotherapy prior to radical hysterectomy in cervical cancer: monitoring tumour shrinkage and molecular profile on magnetic resonance and assessment of 3-year outcome.

The objective of this study is to assess tumour response to neoadjuvant chemotherapy prior to radical hysterectomy in cervical cancer using magnetic resonance (MR) to monitor tumour volume and changes in molecular profile and to compare the survival to that of a control group. Eligibility included Stage Ib-IIb previously untreated cervical tumours >10 cm(3). Neoadjuvant chemotherapy in 22 patients (methotrexate 300 mg x m(-2) (with folinic acid rescue), bleomycin 30 mg x m(-2), cisplatin 60 mg m(-2)) was repeated twice weekly for three courses and followed by radical hysterectomy. Post-operative radiotherapy was given in 14 cases. A total of 23 patients treated either with radical surgery or chemoradiotherapy over the same time period comprised the nonrandomised control group. MR scans before and after neoadjuvant chemotherapy and in the control group documented tumour volume on imaging and metabolites on in vivo spectroscopy. Changes were compared using a paired t-test. Survival was calculated using the Kaplan-Meier method. There were no significant differences between the neoadjuvant chemotherapy and control groups in age (mean, s.d. 43.3+/-10, 44.7+/-8.5 years, respectively, P=0.63) or tumour volume (medians, quartiles 35.8, 17.8, 57.7 cm(3) vs 23.0, 15.0, 37.0 cm(3), respectively, P=0.068). The reduction in tumour volume post-chemotherapy (median, quartiles 7.5, 3.0, 19.0 cm(3)) was significant (P=0.002). The reduction in -CH(2) triglyceride approached significance (P=0.05), but other metabolites were unchanged. The 3-year survival in the chemotherapy group (49.1%) was not significantly different from the control group (46%, P=0.94). There is a significant reduction in tumour volume and -CH(2) triglyceride levels after neoadjuvant chemotherapy, but there is no survival advantage.

Adult↗
PubMed2004

Dispersal and size fractionation of embryogenic callus increases the frequency of embryo maturation and conversion in hybrid tea roses.

Plant regeneration from embryogenic cells of two Rosa hybrida cultivars, Kardinal and Classy, was increased by dispersing embryogenic callus in liquid medium for 3 h followed by size-fractionation to isolate proembryogenic masses that were smaller than 530 microm. Dispersed callus of three cultivars, Kardinal, Classy, and Tineke, produced 61-135 cotyledonary-stage embryos/100 mg fresh weight (FW) as compared to intact callus that had not been dispersed, which produced only zero to three cotyledonary-stage embryos/100 mg FW. Over 500 cotyledonary-stage embryos/100 mg FW callus developed from proembryogenic masses of Kardinal, Classy, and Tineke following 2 months of culture on solidified Murashige and Skoog's basal salts medium supplemented with 0.25% activated charcoal. Cotyledonary-stage embryos of Classy that developed from both dispersed callus and fractionated cells of various sizes showed a significantly higher conversion frequency to plants (28%) than cotyledonary-stage embryos isolated from intact callus (9%). The highest conversion frequencies for Kardinal (50-58%) occurred from cotyledonary-stage embryos that developed from dispersed callus and from the fraction of cells smaller than 850 microm.

Cotyledon↗
PubMed2004

Demographics and macroeconomic effects in aesthetic surgery in the UK.

Media interest in aesthetic surgery is substantial and suggestions of demographic changes such as reductions in age or an increase in the number of male patients are common. In spite of this, there is no peer reviewed literature reporting demographics of a contemporary large patient cohort or of the effect of macroeconomic indicators on aesthetic surgery in the UK. In this study, computer records 13006 patients presenting between 1998 and the first quarter of 2003 at a significant aesthetic surgery centre were analysed for procedures undergone, patient age and sex. Male to female ratios for each procedure were calculated and a comparison was made between unit activity and macroeconomic indicators. The results showed that there has been no significant demographic change in the procedures studied with patient age and male to female ratio remaining constant throughout the period studied for each procedure. Comparison with macroeconomic indicators suggested increasing demand for aesthetic surgery in spite of a global recession. In conclusion, media reports of large scale demographic shifts in aesthetic surgery patients are exaggerated. The stability of unit activity in spite of falling national economic indicators suggested that some units in the UK might be relatively immune to economic vagaries. The implications for training are discussed.

Adult↗
PubMed2004

Antirecipient helper and cytotoxic T-cell frequencies in bone marrow transplantation.

We assayed helper T-lymphocyte precursor frequencies (HTLPf), interferon (IFN)-gamma-producing cell frequencies (IFN-gammaPf) and CTL precursor frequencies (CTLPf) to see if they could predict the severity of acute graft-versus-host disease (aGVHD) and disease relapse after transplantation. In all, 48 bone marrow transplantation (BMT) patients and their HLA-identical sibling (n=29) or matched unrelated donors (MUD) (n=19) were recruited. HTLPf, IFN-gammaPf and CTLPf were measured using a limiting dilution assay (LDA). Patients were followed prospectively to assess the severity of aGVHD and the status of the primary disease after BMT. High (>5 x 10(-6)) HTLPf, CTLPf and IFN-gammaPf were significantly associated with the occurrence and severity of aGVHD in patients who received transplants from HLA-identical sibling. Among patients receiving BMT from MUD, HTLPf and CTLPf, but not IFN-gammaPf, were associated with aGVHD. Five patients had disease relapse post-BMT and the risk was not significantly associated with HTLPf, CTLPf or IFN-gammaPf. Patients with high (>5 x 10(-6)) HTLPf, IFN-gammaPf or CTLPf before BMT are at higher risk of developing aGVHD after transplantation from both matched sibling donors and MUD. Whether these parameters can predict disease relapse would have to be investigated with a larger cohort of patients.

Adult↗
PubMed2004

Haematopoietic necrosis in a goldfish (Carassius auratus) associated with an agent morphologically similar to herpesvirus.

One of 14 goldfish (Carassius auratus) died 4 weeks after purchase and was investigated by necropsy and histological examination. Routine formalin fixation of the goldfish was followed by histopathology. Formalin fixed spleen and kidney from the fish was further processed by embedding in epoxy resin and examined by transmission electron microscopy (EM). Severe, diffuse necrosis of haematopoietic tissue in the spleen, thymus and kidney and severe, diffuse hyperplasia in the gill epithelial cells were seen. In the spleen there was severe, diffuse necrosis of lymphocytes and many nuclei with marginated chromatin and intranuclear inclusions were scattered throughout the necrotic tissue. EM of affected tissues demonstrated intranuclear particles morphologically similar to herpesvirus. The presence of an agent similar to a herpesvirus in a goldfish with severe haematopoietic necrosis suggests that the herpesvirus responsible for haematopoietic necrosis in cyprinid species throughout the world has entered the goldfish population in Australia.

Animals↗
PubMed2004

Quantification of tumour response to radiotherapy.

In 1979, the World Health Organization (WHO) established criteria based on tumour volume change for classifying response to therapy as (i) progressive disease (PD), (ii) partial recovery (PR), and (iii) no change (NC). Typically, the tumour volume is reported from diameter measurements, using the calliper method. Alternatively, the Cavalieri method provides unbiased volume estimates of any structure without assumptions about its shape. In this study, we applied the Cavalieri method in combination with point counting to investigate the changes in tumour volume in four patients with high grade glioma, using 3D MRI. In particular, the volume of tumour within the enhancement boundary, the enhancing abnormality (EA), was estimated from T(1) weighted images, and the volume of the non-enhancing abnormality, (NEA) enhancing abnormality, was estimated from T(2) relaxation time and magnetic transfer ratio tissue characterization maps. We compared changes in tumour volume estimated by the Cavalieri method with those obtained using the calliper method. Absolute tumour volume differed significantly between the two methods. Analysis of relative change in tumour volume, based on the WHO criteria, provided a different classification using the calliper and Cavalieri methods. The benefit of the Cavalieri method over the calliper method in the estimation of tumour volume is justified by the following factors. First, Cavalieri volume estimates are mathematically unbiased. Second, the Cavalieri method is highly efficient under an appropriate sampling density (i.e. EA volume estimates can be obtained with a coefficient of error no higher than 5% in 2-3 min). Third, the source of variation of the volume estimates due to disagreements between observers, and within observer, is much greater in the positioning of the calliper diameters than in the identification of the tumour boundaries when applying the Cavalieri method. Additionally, the error prediction formula, available to estimate the coefficient of error of Cavalieri volume estimates from the data, allows us to establish more precise classification criteria against which to identify potentially clinical significant changes in tumour volume.

Brain Neoplasms↗
PubMed2003

Isolation and characterization of four ethylene perception elements and their expression during ripening in pears (Pyrus communis L) with/without cold requirement.

Pear (Pyrus communis L.) are climacteric fruit: their ripening is associated with a burst of autocatalytic ethylene production. Some late pear cultivars, such as Passe-Crassane (PC) require a long (80 d) chilling treatment before the fruit will produce autocatalytic ethylene and ripen. As the cold requirement is linked to the capacity to respond to ethylene (or its analogue, propylene), three pear cDNAs homologous to the Arabidopsis ethylene receptor genes At-ETR1, At-ERS1, and At-ETR2, designated Pc-ETR1a (AF386509), Pc-ERS1a (AF386515), and Pc-ETR5 (AF386511), respectively, have been isolated. A pear homologue of the Arabidopsis ethylene signal transduction pathway gene At-CTR1, called Pc-CTR1 (AF386508) has also been isolated. The search of the genomic sequences for Pc-ETR1a and Pc-ERS1a resulted in the isolation of four related genomic clones Pc-DETR1a (AF386525), Pc-DETR1b (AF386520), Pc-DERS1a (AF386517), and Pc-DERS1b (AF386522). Analysis of transcript levels for the four cDNAs in PC and pear fruit genotypes with little or no cold requirement revealed that Pc-ETR1a expression increased during chilling treatment, and Pc-ETR1a, Pc-ERS1a, Pc-ETR5, and Pc-CTR1 expression increased during fruit ripening and after ethylene treatment. Whether the differences in the ethylene response elements studied here are the cause or an effect of the cold requirement in PC fruit is discussed.

Acclimatization↗