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Biomedical subjects

R E Taylor

Publications and source records attributed to R E Taylor.

At least 55 records · Page 3Linked to original sources
PubMed1997

Identification, cloning, and mutational analysis of the casein kinase 1 cDNA of the malaria parasite, Plasmodium falciparum. Stage-specific expression of the gene.

The cDNA for casein kinase 1 (CK1) of Plasmodium falciparum was cloned, sequenced, and expressed in bacteria. The single major open reading frame of the 1.2-kilobase pair cDNA coded for a 324-amino acid polypeptide of approximately 37 kDa, the predicted sequence of which showed strong identity with known CK1 isoforms. The purified recombinant enzyme exhibited properties characteristic of CK1, such as inhibition by CK1-7, the ability to phosphorylate a highly specific peptide substrate, and a strong preference for ATP over GTP. A casein kinase activity, partially purified from soluble extracts of P. falciparum by affinity chromatography through CK1-7 columns displayed identical properties. The activity showed a stage-specific expression in the parasite, in the order trophozoite > ring >> schizont. Northern analysis indicated the existence of two major CK1 mRNAs, 2.4 and 3.2 kilobase pairs long, the levels of which were in the order ring > schizont > trophozoite. Mutagenesis of recombinant CK1 defined important amino acid residues and their potential role in the conformation of the enzyme. The malarial CK1 appeared to be the one of the smallest and perhaps the most primitive CK1 enzymes known, containing little sequence information beyond the minimal catalytic domain.

Amino Acid Sequence↗
PubMed1997

The quality of life of patients with paranoid schizophrenia in London and Berlin.

This study compared the subjective and objective quality of life and needs of patients with paranoid schizophrenia between inner city areas in Berlin (69 patients) and London (75 patients). Quality of life was assessed by means of the Lancashire Quality of Life Profile (German version Berliner Lebensqualitatsprofi), and need was quantified using the Camberwell Assessment of Need (German version Berliner Bedurfnisinventar). The hypotheses tested were that although Berlin patients may rate more highly on objective quality of life measures, the subjective quality of life would be similar as patients would judge their quality of life against their local expectations. The findings supported the first part of the hypothesis as on the objective measures the Berlin group was significantly better off financially and in living conditions, and had significantly fewer material needs. However, despite having more severe psychopathology, the Berlin groups' scores on global subjective quality of life were also higher. On particular life domains, subjective quality of life did not always reflect objective measures and sometimes went in the reverse direction. We concluded that the relationship between subjective and objective quality of life is complex, and great caution must be exercised in making quality of life comparisons between different cultures.

Adolescent↗
PubMed1997

Morbidity from abdominal radiotherapy in the First United Kingdom Children's Cancer Study Group Wilms' Tumour Study. United Kingdom Children's Cancer Study Group.

Between 1980 and 1986, 384 children were entered into the UKCCSG First Wilms' Tumour Study (UKW1). For 171 patients receiving abdominal radiotherapy (RT) the early and late toxicity has been analysed. Major early toxicity was significantly more likely with whole abdominal (48%) compared with flank (21%) RT (P = 0.007). An increased risk of major early toxicity, which did not reach statistical significance, was seen with right (20.5%) compared with left (7%) flank RT (P = 0.063) and in those treated with a RT dose of > 20 Gy compared with a dose of < or = 20 Gy (P = 0.103). There were 138 evaluable survivors, with a median follow-up of 127 months. Of these, 33 (23.9%) were reported to have late effects, including 27 musculoskeletal (19.6%), four gastrointestinal (2.9%), and three (of 68 girls) ovarian failure (4.4%). There was no apparent effect of age at diagnosis, RT dose or field size on the risk of developing late effects. The continued surveillance of the long term survivors of Wilms' tumour for the late effects of treatment will be important.

Abdomen↗
PubMed1997

Relation between psychiatric disorder and abnormal illness behaviour in patients undergoing operations for cervical discectomy.

OBJECTIVE: To test the hypothesis that depression in patients being considered for cervical disc surgery is associated with severe organic pathology. Secondly, to test whether depression and abnormal illness attitudes recorded preoperatively would predict poorer recovery. METHODS: Seventy four patients with pain and disability from cervical arthrosis were examined during investigations before potential cervical surgery. The prevalence of psychiatric disorder was assessed using the SCAN, and attitude to illness using the illness attitude scale. RESULTS: There was a rate of depressive disorder in the sample of 37%. The depressed patients did not have more severe organic pathology, more neurological symptoms or signs, or more disablement. They reported more pain and displayed more abnormal illness behaviour. Fifty patients went on to cervical surgery. Outcome four to eight months postoperatively was not related to the presence of psychiatric disorder or illness attitude recorded preoperatively. CONCLUSION: Depressive disorder is not secondary to severe pathology; the outcome of surgery is predominantly determined by physical factors.

Adult↗
PubMed1997

Positive MIBG scanning at the time of relapse in neuroblastoma which was MIBG negative at diagnosis.

Metaiodobenzylguanidine (MIBG) labelled with iodine-123 (123I) or 131I has become a well established tool with high sensitivity and specificity in the diagnosis and staging of neuroblastoma in children. However, some neuroblastomas do not take up MIBG at the time of diagnosis. The reasons for this are unclear but may be related to uptake mechanisms. Follow-up MIBG scans have not been reported in these patients. We present a case where an initial 123I-MIBG-scan was negative at diagnosis but became positive when the patient relapsed. This unusual occurrence may have implications for patients with a negative MIBG-scan at presentation. These patients should be re-evaluated by MIBG-scan at the time of relapse as a positive scan then offers the possibility of additional treatment with MIBG therapy.

3-Iodobenzylguanidine↗
PubMed1996

NMR of laser-polarized xenon in human blood.

By means of optical pumping with laser light it is possible to enhance the nuclear spin polarization of gaseous xenon by four to five orders of magnitude. The enhanced polarization has allowed advances in nuclear magnetic resonance (NMR) spectroscopy and magnetic resonance imaging (MRI), including polarization transfer to molecules and imaging of lungs and other void spaces. A critical issue for such applications is the delivery of xenon to the sample while maintaining the polarization. Described herein is an efficient method for the introduction of laser-polarized xenon into systems of biological and medical interest for the purpose of obtaining highly enhanced NMR/MRI signals. Using this method, we have made the first observation of the time-resolved process of xenon penetrating the red blood cells in fresh human blood-the xenon residence time constant in the red blood cells was measured to be 20.4 +/- 2 ms. The potential of certain biologically compatible solvents for delivery of laser-polarized xenon to tissues for NMR/MRI is discussed in light of their respective relaxation and partitioning properties.

Erythrocytes↗
PubMed1996

Cancer in children: radiotherapeutic approaches.

Radiotherapy is an important treatment modality for 40-50% of children with cancer. There is concern about late effects, particularly the neuropsychological effects of CNS irradiation, and orthopaedic effects. It is important to administer the highest standard of radiotherapy, incorporating departmental quality assurance. Meticulous planning is essential to achieve local tumour control with the minimum of irradiation to normal tissues in order to minimise late effects. Current developments include better definition of tumour extent with MR scanning, and the use of 3D planning and conformal techniques to precisely match the radiotherapy target volume to the tumour. For some CNS tumours the role of stereotactically directed radiotherapy is being explored. Interactions with chemotherapy are important to improve the therapeutic ratio, however increased normal tissue toxicity can be problematic. Radiotherapy for children should be undertaken only in departments linked to specialised paediatric oncology centres.

Child↗
PubMed1995

Effect of in vitro incorporation of prostanoid precursors, superoxide radical and hydrogen peroxide on platelet function.

The level of cyclic adenosine monophosphate (cAMP) in human platelets is known to be an important regulator of platelet function. The polyunsaturated fatty acids (PUFA) dihomo-gamma-linolenic acid (DHLA), and eicosapentaenoic acid (EPA), precursors of the prostaglandin (PG) 1 and 3 series respectively, were studied for their ability to stimulate platelet cAMP and/or PGE1 levels, and to inhibit platelet aggregation (PAg). Incubation of washed platelets (1 x 10(8)/ml) with 125 microM DHLA increased intraplatelet levels of PGE1 from 197 +/- 7 to 1622 +/- 9.7 picograms/10(8), cAMP from 3 +/- 0.8 to 31 +/- 1.9 picomoles/10(8), and inhibited collagen-induced PAg. Addition of 1 mumole of xanthine per unit of xanthine oxidase (a superoxide radical generating system) to the incubating medium potentiated the effects of both fatty acids, whereas 240 microM Hydrogen Peroxide (H2O2) inhibited these effects. These results suggest that: (1) DHLA may be more effective in inhibiting PAg than EPA, which has been reported to reduce the incidence of coronary diseases in some human populations; (2) That superoxide radical may activate the platelet cyclooxygenase system to increase lipid peroxidation of these PUFA prostanoid precursors and may result in the inhibition of PAg, whereas H2O2 may have an opposite effect.

8,11,14-Eicosatrienoic Acid↗
PubMed1993

Salivary gland carcinomas in children: a review of 15 cases.

Salivary gland carcinomas are rare in childhood. We have reviewed the case records of 15 children aged 3-14 years (median 11) identified from children's tumour registries. Primary sites were parotid: 11, submandibular: 3, and base of tongue: 1. The range of histologies was similar to that occurring in adults. Six were treated by complete excision, with one given post-operative radiotherapy (RT). All six remain disease-free at 2 months to 21 years after completion of treatment. Five were treated by partial or sub-total excision. Four were given post-operative RT, of whom 3 are disease-free at 3 years, 6 months--18 years and 1 lost to follow-up (LTFA). One not given RT developed a local recurrence at 11 months and was given RT and LTFA. Four patients had a biopsy only. Three were treated by RT. One is disease-free at 8 years, one died of metastatic disease at 6 months, and one developed a local recurrence at 11 years and has remained disease-free following salvage surgery. One patient with advanced disease not suitable for RT died 3 months after diagnosis. Complete excision is the treatment of choice. Following sub-total or incomplete excision post-operative RT can prevent recurrence. Careful RT planning is necessary to minimise late effects.

Adenocarcinoma↗
PubMed1993

Factors contributing to dystocia due to fetal malpresentation in beef cattle.

Records on 3873 calvings over a 21-year period (1971 to 1991) from the Colorado State University Resident Instruction beef cattle herd were used to examine factors associated with malpresentations at birth. Approximately 82% of the calvings were unassisted and 18% were assisted in some manner. Of the assisted deliveries, severe traction, mild traction, malpresentation and caesarean section accounted for 44.5, 31.8, 22.4 and 1.3%, respectively, of the total. Ninety-six percent of all births were normal presentations and 4% were malpresentations. The incidence of malpresentations was affected by year, sex of calf, and sire of calf within breed. Most of the malpresentations were in the posterior dorsal position (72.8%) followed by unilateral carpal or shoulder flexion (11.4%), breech (8.2%), lateral deviation of the head (2.5%), incomplete extension of the elbow (1.9%), posterior ventral (1.3%), transverse (1.3%) and oblique ventro-vertical (0.6%). Factors influencing the incidence of posterior dorsal presentations were year, sex of calf, sire of calf within breed, and age of dam. Malpresentation heritability estimates as traits of the calf were 0.088 and 0.003 for Hereford and Angus breeds, respectively. Posterior presentation heritability estimates for Hereford and Angus cattle were 0.173 and 0.0, respectively. Heritabilities as traits of the dam and repeatabilities for malpresentation, and posterior presentation were minimal.

Journal Article↗
PubMed1993

Changes in target volume during radiotherapy treatment of invasive bladder carcinoma.

Ninety patients with stage T3 Nx Mo carcinoma of the urinary bladder were treated with radical megavoltage external beam radiotherapy. Planning for treatment was undertaken on a treatment planning system utilizing CT scan slices to define the target volume and patient outline. All patients underwent a second CT scan half way through their course of treatment to assess any change in target volume and the continued adequacy of the original treatment plan. Seventy-two patients (80%) had no spatial shift in target volume, but, of the 18 patients with such a shift, treatment plans were changed in seven. The majority of patients had no delay in continuing their treatment after replanning, but one patient had a gap of 5 days before restarting treatment. An analysis of the factors possibly associated with a change in target volume showed that a primary tumour at the bladder base, rather than elsewhere in the bladder, was the single most important criterion for predicting target volume changes. There was no correlation between the size of the initial tumour, or the size of the prostate gland in male patients, and the occurrence of a shift in volume outside the initial target volume. Some method of regularly assessing the continued relevance of the target volume may be needed in this group of patients to improve the precision of treatment and also improve results.

Aged↗
PubMed1992

Recurrent tonsillitis. The role of Chlamydia and Mycoplasma.

The core tissue microflora of 40 patients who underwent tonsillectomies were examined with cultures, DNA probe tests, enzyme immunoassays, and direct immunofluorescence antibody tests for Chlamydia and Mycoplasma. We believe this is the largest and most accurate prospective study that has examined the role of Chlamydia and Mycoplasma in the core tonsil tissue of patients with recurrent or chronic tonsillitis. The data strongly indicate that, unlike acute tonsillopharyngitis, Chlamydia and Mycoplasma are not involved in recurrent or chronic tonsillitis.

Adolescent↗
PubMed1992

Enhanced normal tissue response to radiation in a patient with discoid lupus erythematosus.

We report the case of a patient with discoid lupus erythematosus who developed a severe skin reaction whilst undergoing mantle irradiation for non-Hodgkin's lymphoma. Widespread moist desquamation occurred after a skin dose of only 17 Gy and was associated with an abscopal response outside the treatment area. The case illustrates the need for extreme caution when administering radiotherapy to patients with discoid or systemic lupus erythematosus.

Female↗
PubMed1991

Low dose bleomycin with etoposide and cisplatin for metastatic testicular teratoma.

Thirty-nine men with metastatic testicular teratoma were treated with a combination of bleomycin, etoposide and cisplatin (BEP). Unlike the usual regimen of these 3 agents, bleomycin and cisplatin were given on day 1 only of the cycle, with etoposide for 3 days. Thirty patients (77%) are alive and disease-free after a median follow-up of 31 months--24/25 (96%) with disease confined to lymph nodes but only 6/14 (43%) patients with lung involvement. Modified BEP chemotherapy is a well tolerated alternative to standard BEP chemotherapy for small volume nodal disease; it minimises in-patient time, hospital visits and the risk of bleomycin lung toxicity. However, omission of the weekly doses of bleomycin and shortening of the administration schedule of cisplatin and etoposide may be detrimental in patients with more extensive disease, for whom more intensive therapy may be necessary.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1990

Recruiting black medical students: a decade of effort.

Beginning in the mid-1960s, the enrollment of African-Americans in the nation's colleges of medicine began to rise dramatically, but by 1975 it had leveled off, and it has since remained essentially unchanged at 6 to 7%. The University of Tennessee College of Medicine failed to increase its enrollment of black students during the period of dramatic growth, and it consistently ranked among the bottom one-fourth of U.S. medical schools in this respect until the fall of 1988. With the enrollment of 17 first-time, first-year African-American students for both the 1988-89 and 1989-90 academic years, the college now ranks in the top one-fourth of the nation's medical schools in this regard. This essay chronicles the events, discoveries made through self-analysis, new programs, changes in operating procedure, and institutional commitment that led eventually to this improvement. Based on a decade of experience, the authors recommend that UT Memphis and all other U.S. colleges of medicine become directly, but appropriately, involved in students' education far earlier than traditionally considered to be within their domain. If lasting and effective alliances can be established with institutions of primary, secondary, and undergraduate college education, it should be possible to escape from the persistent and perplexing problem of stagnation in the growth of black enrollment.

Black or African American↗