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J Sawyer

Publications and source records attributed to J Sawyer.

At least 19 recordsLinked to original sources
PubMed2006

Development of a real time PCR for the detection of Taylorella equigenitalis directly from genital swabs and discrimination from Taylorella asinigenitalis.

A discriminatory real time PCR for the detection of Taylorella equigenitalis, the causative agent of contagious equine metritis (CEM), and the related species T. asinigenitalis was developed for the direct examination of genital swabs. The 112bp amplicons produced from the two species were discriminated from each other using TaqMan probes labelled with different fluorophores. The TaqMan PCR was shown to be specific for the 16S ribosomal DNA of the two species of taylorella and did not cross-hybridise with the 16S ribosomal DNA of other bacteria tested. Direct amplification from genital swabs was shown to be equally sensitive to that of culture methods. Prevalence in a sample set from The Netherlands was shown to be equivalent to that demonstrated by culture. A companion real time PCR that amplified a fragment of the 16S rDNA gene of equine commensal bacteria was developed to ensure bacterial DNA was extracted from swab material supplied for testing. The use of a rapid and reliable real time PCR for the organism causing CEM should aid the control of this disease.

Animals↗
PubMed2006

Practical experiences of moving molecular diagnostics into routine use at the Veterinary Laboratories Agency.

The practical bench application of molecular tests (here defined as nucleic acid-based tests) in a routine testing situation is not without its challenges. This paper outlines the approaches we take at the Veterinary Laboratories Agency (VLA) and highlights some of the practical issues which we have found to be important for the successful introduction and use of molecular tests in a routine testing environment. The potential advantages of molecular tests, and factors which dictate which tests are adopted for routine testing, are discussed before giving some examples of molecular tests in routine use at the VLA. The instrumentation, reagents and assays we use are outlined, followed by sections of how we approach validation and how we manage and resource the transfer of molecular tests into routine use.

Laboratories↗
PubMed2006

Development of a real-time, differential RT-PCR TaqMan assay for lyssavirus genotypes 1, 5 and 6.

A number of RT-PCR methods have been reported for the detection of rabies and rabies-related viruses. Here, a single, closed tube, non-nested RT-PCR TaqMan assay to distinguish between Classical rabies virus and European bat lyssaviruses 1 and 2 in real time is described. The TaqMan assay is rapid, sensitive, specific and allows for the genotyping of unknown isolates concomitant with the RT-PCR. It can be applied quantitatively and the use of an internal control enables the quality of the isolated template to be assessed. The efficiency and dynamic range of the PCR has been established using isolated viral RNA and cloned control template. Comparative performance of the TaqMan assay against other diagnostic methodologies for the detection of rabies virus has been determined and the assay validated against a panel of archival samples and virus of unknown genotype from both Germany and the Sudan. Despite sequence heterogeneity between the different genotypes in the N-gene, a universal forward and reverse primer set have been designed allowing simplification of previously described assays. Rapid genotyping of two recent EBLV2 cases in the U.K. in Daubenton's bats and a recently imported human case of rabies has been performed using this test.

Animals↗
PubMed2005

Malignant pleural effusion of multiple myeloma: prognostic factors and outcome.

Malignant pleural effusion (MPE) in multiple myeloma (MM) is rare. Approximately 80 cases have been reported. To delineate optimal treatment and prognostic variables in these patients, we reviewed 11 MM patients with MPE. MPE developed at median of 12 months from diagnosis of MM. All the patients had high-risk disease based on complex karyotypic abnormalities including deletions of chromosome-13 (n=9), elevated beta-2 microglobulin (B2M) (n=9), high C-reactive protein (CRP) (n=8), high plasma cell labeling index (n=5) or high LDH (n=5). A significant increase in B2M, LDH, and CRP was observed at the onset of MPE. The initial diagnosis of MPE was based on positive cytology (n=9), pleural fluid cIg/DNA (n=9) or pleural fluid cytogenetics (n=4). Pleural tissue infiltration was found on pleural biopsy and autopsy in one patient each. Systemic chemotherapy comprising dexamethasone, cyclophosphamide, etoposide and cisplatin (DCEP) (n=7) and pleurodesis (n=7) were effective in resolving MPE but survival was short. High dose chemotherapy with peripheral blood stem cell support for MPE in six patients conferred no clear survival advantage. These patients died at median of four months from onset of MPE. Patients with bone marrow complex karyotypic abnormalities including deletion-13 (n=9) had a shorter (median--18 months) overall survival compared to patients with normal cytogenetics (median--38 months). MPE in patients with MM is often associated with high-risk disease including deletion 13 chromosomal abnormality and heralds a poor prognosis despite aggressive local and systemic treatment.

Adult↗
PubMed2005

Screens using RNAi and cDNA expression as surrogates for genetics in mammalian tissue culture cells.

We have developed methods for the automation of transfection-grade DNA preparation, high-throughput retroviral preparation, and highly parallel phenotypic screens to establish approaches that will allow investigators to examine in an unbiased manner the roles of proteins in mammalian cells. These methods have been used to raise or lower the levels of individual kinases in individual micro-well cultures either by cDNA or short hairpin RNA expression and will allow investigators to treat mammalian cells in culture in manners that are analogous to genetic screens in yeast. Our proof-of-principle experiments have been performed in human cells using repositories that represent over 75% of the protein, nucleotide, carbohydrate, lipid, and amino acid kinases in the human genome. These initial experiments have demonstrated the feasibility of two general types of screens. We have performed phenotypic screens to identify proteins with specific roles in a chosen function and genetic interaction screens to establish epistatic relations between different proteins. The results suggest that any phenotype that can be scored by a robust assay in tissue culture is amenable to these types of screens and that interactions between mammalian proteins can be established. These results point to the near-term goal of establishing comprehensive, unbiased screens that will allow queries on the roles of all human proteins.

Carcinoma, Non-Small-Cell Lung↗
PubMed2005

Development of a real-time, TaqMan reverse transcription-PCR assay for detection and differentiation of lyssavirus genotypes 1, 5, and 6.

Several reverse transcription-PCR (RT-PCR) methods have been reported for the detection of rabies and rabies-related viruses. These methods invariably involve multiple transfers of nucleic acids between different tubes, with the risk of contamination leading to the production of false-positive results. Here we describe a single, closed-tube, nonnested RT-PCR with TaqMan technology that distinguishes between classical rabies virus (genotype 1) and European bat lyssaviruses 1 and 2 (genotypes 5 and 6) in real time. The TaqMan assay is rapid, sensitive, and specific and allows for the genotyping of unknown isolates concomitant with the RT-PCR. The assay can be applied quantitatively and the use of an internal control enables the quality of the isolated template to be assessed. Despite sequence heterogeneity in the N gene between the different genotypes, a universal forward and reverse primer set has been designed, allowing for the simplification of previously described assays. We propose that within a geographically constrained area, this assay will be a useful tool for the detection and differentiation of members of the Lyssavirus genus.

Animals↗
PubMed2003

Extreme spore UV resistance of Bacillus pumilus isolates obtained from an ultraclean Spacecraft Assembly Facility.

Recent environmental microbial sampling of the ultraclean Spacecraft Assembly Facility at NASA Jet Propulsion Laboratory (JPL-SAF) identified spores of Bacillus pumilus as major culturable bacterial contaminants found on and around spacecraft. As part of an effort to assess the efficacy of various spacecraft sterilants, purified spores of 10 JPL-SAF B. pumilus isolates were subjected to 254-nm UV and their UV resistance was compared to spores of standard B. subtilis biodosimetry strains. Spores of six of the 10 JPL-SAF isolates were significantly more resistant to UV than the B. subtilis biodosimetry strain, and one of the JPL-SAF isolates, B. pumilus SAFR-032, exhibited the highest degree of spore UV resistance observed by any Bacillus spp. encountered to date.

Analysis of Variance↗
PubMed2003

Promoter polymorphism in the 5-lipoxygenase (ALOX5) and 5-lipoxygenase-activating protein (ALOX5AP) genes and asthma susceptibility in a Caucasian population.

BACKGROUND: 5-Lipoxygenase (5-LO) and 5-lipoxygenase-activating protein (FLAP) are essential for cysteinyl-leukotriene (cys-LT) production, critical mediators in asthma. OBJECTIVE: We sought to identify novel promoter polymorphisms within the FLAP (ALOX5AP) gene promoter and test the role of these and the previously identified 5-LO (ALOX5) Sp1 promoter polymorphism in asthma susceptibility. METHODS: To assess genetic association with asthma phenotypes, we genotyped 341 Caucasian families (containing two asthmatic siblings) and non-asthmatic control subjects (n=184). Genetic association was determined by case-control and transmission disequilibrium test (TDT) analyses. To determine the functional role of polymorphisms on basal transcription, we generated ALOX5AP-promoter-luciferase constructs and transiently transfected human HeLa cells. RESULTS: A novel G/A substitution at -336 bp and a poly(A) repeat (n=19 or 23) at position -169 to -146 bp were identified in the ALOX5AP promoter. Genotyping found the -336 A and poly(A19) alleles at frequencies of q=0.06 and 0.12, respectively. No ALOX5AP allele was associated with asthma or asthma-related phenotypes in case-control or TDT analyses. ALOX5AP-promoter-luciferase analyses did not support a functional role of the -336 or poly(A) polymorphism in determining basal transcription. The ALOX5 Sp1 polymorphism was predominantly homozygous wild-type 5/5 (frequency q=0.70) and heterozygous 4/5 (q=0.23) genotypes and no allele was associated with asthma or asthma-related phenotypes. CONCLUSION: Taken together, these data do not support a significant role for these polymorphisms in genetic susceptibility to asthma in the Caucasian population.

5-Lipoxygenase-Activating Proteins↗
PubMed2002

The effects of botulinum toxin treatment on associated reactions of the upper limb on hemiplegic gait--a pilot study.

PURPOSE: The involuntary movements of the paretic arm during ambulation and other motor activities are known as associated upper limb reactions (ARs). ARs occur in 80% of stroke patients with spastic hemiplegia and often interfere with balance and safe mobilization. It is hypothesized that the treatment of localized muscle spasticity with botulinum toxin type A (BtxA) would abolish the ARs and improve balance and mobility. METHOD: This hypothesis will need to be tested in a randomized controlled trial (RCT). The aim of the present pilot study is to obtain preliminary data to inform the design of a future RCT. Eight patients received a single injection of 500 units of BtxA (Dysport((R)) Ipsen, Ltd) into the biceps brachii of the paretic arm. The patients' balance and mobility were assessed before and 2, 4 and 6 weeks after treatment using observational gait analysis and other subjective assessment scales. RESULTS: There was a significant reduction of the ARs after treatment but this did not appear to improve the patients' balance or mobility as assessed by the clinicians. Interestingly, seven out of the eight patients reported improvement in their walking. CONCLUSION: The discrepancy between the observed and reported effects of treatment could be due to the poor sensitivity of the outcome measures used in this study.

Adult↗
PubMed2001

Cyclin D3 at 6p21 is dysregulated by recurrent chromosomal translocations to immunoglobulin loci in multiple myeloma.

Reciprocal chromosomal translocations, which are mediated by errors in immunoglobulin heavy chain (IgH) switch recombination or somatic hypermutation as plasma cells are generated in germinal centers, are present in most multiple myeloma (MM) tumors. These translocations dysregulate an oncogene that is repositioned in proximity to a strong IgH enhancer. There is a promiscuous array of nonrandom chromosomal partners (and oncogenes), with the 3 most frequent partners (11q13 [cyclin D1]; 4p16 [FGFR3 and MMSET]; 16q23 [c-maf]) involved in nearly half of MM tumors. It is now shown that a novel t(6;14)(p21;q32) translocation is present in 1 of 30 MM cell lines and that this cell line uniquely overexpresses cyclin D3. The cloned breakpoint juxtaposes gamma 4 switch sequences with 6p21 sequences that are located about 65 kb centromeric to the cyclin D3 gene. By metaphase chromosome analysis, the t(6;14) (p21;q32) translocation was identified in 6 of 150 (4%) primary MM tumors. Overexpression of cyclin D3 messenger RNA (mRNA) was identified by microarray RNA expression analysis in 3 of 53 additional primary MM tumors, each of which was found to have a t(6;14) translocation breakpoint by interphase fluorescence in situ hybridization analysis. One tumor has a t(6;22)(p21;q11) translocation, so that cyclin D3 is bracketed by the IgL and IgH breakpoints. These results provide the first clear evidence for primary dysregulation of cyclin D3 during tumorigenesis. It is suggested that the initial oncogenic event for most MM tumors is a primary immunoglobulin translocation that dysregulates cyclin D1, cyclin D3, and other oncogenes to provide a proliferative stimulus to postgerminal center plasma cells.

Bone Marrow Cells↗
PubMed2001

Development and testing of the Migraine Disability Assessment (MIDAS) Questionnaire to assess headache-related disability.

The MIDAS Questionnaire was developed to assess headache-related disability with the aim of improving migraine care. Headache sufferers answer five questions, scoring the number of days, in the past 3 months, of activity limitations due to migraine. The internal consistency, test-retest reliability, and validity (accuracy) of the questionnaire were assessed in separate population-based studies of migraine sufferers. In addition, the face validity, ease of use, and clinical utility of the questionnaire were evaluated in a group of 49 physicians who independently rated disease severity and need for care in a diverse sample of migraine case histories. The test-retest Pearson correlation coefficient for the total MIDAS score was approximately 0.8. The MIDAS score was valid when compared with a reference diary-based measure of disability; the overall correlation between MIDAS and the diary-based measure was 0.63. The MIDAS score was also correlated with physicians' assessments of need for medical care (r = 0.69). From studies completed to date, the MIDAS Questionnaire has been shown to be internally consistent, highly reliable, valid, and correlates with physicians' clinical judgment. These features support its suitability for use in clinical practice. Use of the MIDAS Questionnaire may improve physician-patient communication about headache-related disability and may favorably influence health-care delivery for migraine patients.

Disability Evaluation↗
PubMed2001

The cost effectiveness of stratified care in the management of migraine.

OBJECTIVE: To examine the cost effectivess of a stratified-care regimen for patients with migraine--in which patients are stratified by severity of illness, and then prescribed differing treatments according to level of severity--compared with a conventional stepped-care approach. DESIGN AND METHODS: A decision analytic model was constructed to simulate a controlled clinical trial in which patients with migraine receiving primary medical care were randomly assigned to treatment under a stepped-care or a stratified-care regimen. A health service payer perspective was adopted and the time horizon was 1 year. Data inputs were: (i) the frequency and disability of migraine, derived from population-based studies; (ii) disability level-specific treatment response rates for over-the-counter analgesics,aspirin/metoclopramide and zolmitriptan as the representative of high-end therapy obtained from an international consensus opinion enquiry; and (iii) unit costs of healthcare obtained from UK health service sources. MAIN OUTCOME MEASURES AND RESULTS: The estimated 1-year direct healthcare costs per primary care patient with migraine were pound sterling 156.82 for stepped care and sterling pound 151.57 for stratified care. Estimates of treatment response rates were 40 and 71% for stepped and stratified care, respectively. The cost per successfully treated attack was sterling pound 23.43 for stepped care and sterling pound 12.60 for stratified care. Stratified care remained cost effective when tested in a wide range of one-way sensitivity analyses, and probabilistic sensitivity analysis showed the cost effectiveness of stratified care to be significant at the 3% level. Conditional confidence analysis showed that the level of confidence in the cost effectiveness of stratified care varied positively with the case mix, i.e. in populations where the proportion of moderate and severely disabled patients with migraine was greater than 25%, the cost effectiveness of stratified care remained statistically significant. CONCLUSION: A stratified-care treatment strategy (including zolmitriptan as the representative of high-end therapy) is a highly cost-effective method of managing migraine in the primary care setting compared with stepped care, delivering improved clinical outcomes at no additional cost.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2001

Clinical utility of an instrument assessing migraine disability: the Migraine Disability Assessment (MIDAS) questionnaire.

OBJECTIVE: We evaluated the agreement between Migraine Disability Assessment (MIDAS) scores and independent physician judgments about pain, disability, and treatment needs based on patient medical histories. BACKGROUND: The MIDAS questionnaire measures headache-related disability as lost time due to headache from paid work or school, household work, and nonwork activities. METHODS: Twelve histories from patients with migraine were presented to 49 primary and specialty care physicians unaware of the MIDAS scores. Physicians graded each patient for pain level (mild, moderate, or severe), level of disability (none, mild, moderate, or severe), and need for medical care (from 0 [lowest] to 100 [highest]). Physicians also identified MIDAS scores they associated with different degrees of disability and with the urgency to prescribe an effective treatment during the first consultation. RESULTS: The physicians' perceptions of the need for medical care based on medical histories correlated with the MIDAS score (r =.69). Estimates of pain and disability by physicians were directly correlated with increasing MIDAS scores. Using the physicians' clinical judgments, the overall MIDAS score was categorized into four grades of increasing severity. CONCLUSIONS: Scores on the MIDAS are highly correlated with physician judgments regarding patients' pain, disability, and need for medical care. These findings support the potential utility of the MIDAS questionnaire in clinical practice.

Disability Evaluation↗
PubMed2000

Menstrual cycle and headache in a population sample of migraineurs.

BACKGROUND: Migraine is three times more common in women than men. There is a clinical impression that migraines are more common and severe around the time of menses. OBJECTIVES: To determine 1) the distribution of headache attacks by day of the menstrual cycle in women with migraine, 2) if the excess occurrence varies by headache type, and 3) if headache features differ by time in the menstrual cycle. METHODS: In a population-based sample, 81 menstruating women with clinically diagnosed migraine were enrolled in a 98-day diary study and completed a total of 7219 diary days. The daily diary was used to record the occurrence of menses, headache days, and, on days with headache, associated headache features (i.e., symptoms, quality-of-pain, attack duration, pain intensity, and disability at work, household work, and nonwork activities). RESULTS: An excess risk of headache occurred perimenstrually and was highest on days 0 and 1 of the cycle (day 0 being the first day of menses). A significantly elevated risk of headache on days 0 and 1 was observed for migraine without aura (OR 2.04; 95% CI 1.49, 2.81) and for tension-type headache (OR 1.67; 95% CI 1.24, 2.25). Elevated risks were also observed in the 2 days before onset of menses for migraine without aura (OR 1.80; 95% CI 1.40, 2.30). A significantly lower risk was observed around the time of ovulation for all headaches (OR 0.44; 95% CI 0.27, 0.72). Few significant differences were observed in headache features (i.e., pain intensity, disability score, symptom score, headache duration) by day of the cycle overall or by headache type. Pain intensity was slightly greater for migraine headaches during the first 2 days of menses. CONCLUSIONS: Attacks of migraine without aura, but not migraine with aura, were more likely to occur 2 days before onset of menses and on the first 2 days of menses. This study does not support the clinical notion that headaches, regardless of type, are more severe during the perimenstrual period compared to other times in the cycle. Although migraine headaches are significantly more painful during the first 2 days of menses, differences are small.

Adolescent↗
PubMed2000

High incidence of chromosome 13 deletion in multiple myeloma detected by multiprobe interphase FISH.

Multiple myeloma (MM) is a hypoproliferative malignancy yielding informative karyotypes in no more than 30% of newly diagnosed cases. Although cytogenetic and molecular deletion of chromosome 13 is associated with poor prognosis, a MM tumor suppressor gene (TSG) has not been identified. To localize a minimal deleted region of chromosome 13, clonotypic plasma cells from 50 consecutive patients with MM were subjected to interphase fluorescence in situ hybridization (FISH) analysis using a panel of 11 probes spanning the entire long arm of chromosome 13. Whereas chromosome 13 abnormalities were absent in plasma cells from 25 normal donors, 86% of patients with MM demonstrated such aberrations. Heterogeneity, both in deletion frequency and extent, was confirmed by simultaneous FISH with 2 chromosome 13 probes. Deletion hot spots were noted at D13S272 (70%) and D13S31 (64%), 2 unlinked loci at 13q14. Homozygous deletions at these loci occurred in 12% (simultaneously in 8%) of the cases. Molecular deletions were found in all 14 patients with morphologic deletions, in 21 of 24 with uninformative karyotypes, and 8 of 12 patients with karyotype abnormalities lacking chromosome 13 deletion. Homozygous deletion of any marker was noted in 4% with low and in 36% with higher plasma cell labeling index greater than 0. 4% (P =.01). The absence of increasing deletion incidence and extent with therapy duration suggests that the observed lesions are not induced by treatment. The high incidence and extent of chromosome 13 deletions require the correlation of specific deletion(s) with poor prognosis. These analyses will provide valuable guidance toward cloning of an MM-TSG. (Blood. 2000;96:1505-1511)

Adult↗
PubMed2000

Results of high-dose therapy for 1000 patients with multiple myeloma: durable complete remissions and superior survival in the absence of chromosome 13 abnormalities.

High-dose therapy (HDT) has increased complete remission (CR) rates and survival in multiple myeloma (MM). We now report on continuous CR (CCR) and associated prognostic factors in 1000 consecutive patients receiving melphalan-based tandem HDT. Five-year CCR was 52% among 112 CR patients without chromosome 13 (triangle up13) abnormalities and with beta-2-microglobulin </= 2.5 mg/L, C-reactive protein </= 4 mg/L, and pre-HDT standard chemotherapy </= 12 months. Of all 390 CR patients without triangle up13 abnormalities, 35% enjoyed 5-year CCR but none of 54 with triangle up13 abnormalities. triangle up13 abnormalities, present in overall 16%, reduced 5-year event-free survival from 20% to 0% and overall survival from 44% to 16% (both P <.0001). CR and a second HDT cycle applied within 6 months both extended event-free and overall survival significantly, justifying further pursuit of HDT, especially toward curing non-triangle up13 MM. (Blood. 2000;95:4008-4010)

Adolescent↗
PubMed2000

DNA hypomethylation and unusual chromosome instability in cell lines from ICF syndrome patients.

The ICF syndrome (immunodeficiency, centromeric region instability, facial anomalies) is a unique DNA methylation deficiency disease diagnosed by an extraordinary collection of chromosomal anomalies specifically in the vicinity of the centromeres of chromosomes 1 and 16 (Chr1 and Chr16) in mitogen-stimulated lymphocytes. These aberrations include decondensation of centromere-adjacent (qh) heterochromatin, multiradial chromosomes with up to 12 arms, and whole-arm deletions. We demonstrate that lymphoblastoid cell lines from two ICF patients exhibit these Chr1 and Chr16 anomalies in 61% of the cells and continuously generate 1qh or 16qh breaks. No other consistent chromosomal abnormality was seen except for various telomeric associations, which had not been previously noted in ICF cells. Surprisingly, multiradials composed of arms of both Chr1 and Chr16 were favored over homologous associations and cells containing multiradials with 3 or >4 arms almost always displayed losses or gains of Chr1 or Chr16 arms from the metaphase. Our results suggest that decondensation of 1qh and 16qh often leads to unresolved Holliday junctions, chromosome breakage, arm missegregation, and the formation of multiradials that may yield more stable chromosomal abnormalities, such as translocations. These cell lines maintained the abnormal hypomethylation in 1qh and 16qh seen in ICF tissues. The ICF-specific hypomethylation occurs in only a small percentage of the genome, e.g., ICF brain DNA had 7% less 5-methylcytosine than normal brain DNA. The ICF lymphoblastoid cell lines, therefore, retain not only the ICF-specific pattern of chromosome rearrangements, but also of targeted DNA hypomethylation. This hypomethylation of heterochromatic DNA sequences is seen in many cancers and may predispose to chromosome rearrangements in cancer as well as in ICF.

5-Methylcytosine↗