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M Smith

Publications and source records attributed to M Smith.

At least 73 records · Page 4Linked to original sources
PubMed2004

Molecular genetic mapping of Gby, a new greenbug resistance gene in bread wheat.

The greenbug, Schizaphis graminum (Rhodani),is one of the major insect pests of wheat worldwide and it is important to develop a basic understanding of the chromosomal locations of known and new greenbug resistance genes. Gby is a new greenbug resistance gene in the wheat line 'Sando's selection 4040'. A mapping population used in this study was derived from a cross of Sando's 4040 and PI220127, a greenbug susceptible wheat land race from Afghanistan. A progeny test indicated that Gby is inherited as a single semi-dominant gene. A genetic linkage map consisting of Gby, Xgwm322 (a wheat microsatellite marker), XksuD2 (an STS marker) and 18 restriction fragment length polymorphism (RFLP) loci was constructed. We used DNA from Chinese Spring 7A deletion lines to show that the gwm332 and ksuD2 amplified fragments mapped in this study are located on along arm of chromosome 7A. This suggests that Gby is located on wheat chromosome 7A. Gby was mapped to the area in the middle of the 'island' of putative defense response genes that are represented by RFLP markers(Xpsr l9, XZnfp, Xbcd98 and Prl b) previously mapped to the distal part of the short arm of wheat chromosome group 7. This region of chromosome 7A is characterized by a high recombination rate and a high physical density of markers which makes Gby a very good candidate for map-based cloning. The selection accuracy when theRFLP markers Xbcd98, Xpsrll9 or XZnfp and Prlb flanking Gby are used together to tag Gby is 99.78%,suggesting that they can be successfully used in marker assisted selection.

Afghanistan↗
PubMed2004

Unintended effects and their detection in genetically modified crops.

The commercialisation of GM crops in Europe is practically non-existent at the present time. The European Commission has instigated changes to the regulatory process to address the concerns of consumers and member states and to pave the way for removing the current moratorium. With regard to the safety of GM crops and products, the current risk assessment process pays particular attention to potential adverse effects on human and animal health and the environment. This document deals with the concept of unintended effects in GM crops and products, i.e. effects that go beyond that of the original modification and that might impact primarily on health. The document first deals with the potential for unintended effects caused by the processes of transgene insertion (DNA rearrangements) and makes comparisons with genetic recombination events and DNA rearrangements in traditional breeding. The document then focuses on the potential value of evolving "profiling" or "omics" technologies as non-targeted, unbiased approaches, to detect unintended effects. These technologies include metabolomics (parallel analysis of a range of primary and secondary metabolites), proteomics (analysis of polypeptide complement) and transcriptomics (parallel analysis of gene expression). The technologies are described, together with their current limitations. Importantly, the significance of unintended effects on consumer health are discussed and conclusions and recommendations presented on the various approaches outlined.

Animals↗
PubMed2004

Aneurysm of the pancreaticoduodenal arteries with a celiac trunk lesion: current management.

OBJECTIVE: We report a ruptured aneurysm of the pancreaticoduodenal arteries without acute or chronic pancreatitis but associated with a median arcuate ligament division that compressed the celiac trunk, an exceptional event, thus far described in only 11 patients. We also conducted a targeted review to seek information about clinical presentation, to hasten diagnosis and assist in therapeutic management. METHODS: A 54-year-old man with retroperitoneal hemorrhage associated with an arcuate ligament division, documented on computed tomographic scans, underwent diagnostic arteriography and embolization to treat the bleeding aneurysm. In a second elective operation the causative arcuate ligament was sectioned to decompress the celiac artery, to prevent aneurysm recurrence. RESULTS: Embolization stopped the aneurysmal bleeding, and arteriograms showed that surgical sectioning resolved the celiac trunk stenosis. At 1-year follow-up the patient had no signs of complications or recurrence of disease. CONCLUSION: Ruptured aneurysm of the pancreaticoduodenal arteries associated with stenosis of the celiac trunk is a surgical emergency. Although a literature review disclosed no significant difference between outcomes after open surgery and radiologic arterial embolization, our experience in this case suggests immediate embolization during arteriography as the most effective treatment. Later, to prevent recurrence, the arcuate ligament should be surgically sectioned and the celiac artery stenosis treated.

Aneurysm, Ruptured↗
PubMed2004

Methylation of tumor suppressor gene p16 and prognosis of epithelial ovarian cancer.

OBJECTIVE: Methylation of p16 promoter was evaluated in ovarian cancer to determine the role of p16 methylation in ovarian cancer prognosis. METHODS: Two hundred and forty-nine patients with primary epithelial ovarian cancer were selected for the study; these patients were followed for a median of 31 months. Genomic DNA extracted from fresh frozen tumor tissues were treated with sodium bisulfite and were analyzed for p16 methylation using methylation-specific PCR (MSP). Cox regression survival analysis was performed to examine the associations of p16 methylation with progression-free and overall survivals. RESULTS: Of the 249 patients, 100 (40%) were tested positive for p16 promoter methylation. The status of p16 methylation did not change significantly with patient age, disease stage, histological grade, residual tumor size, and debulking results, although p16 methylation seemed to occur more often in patients with advanced diseases or aggressive tumors. Compared to those without p16 methylation, patients with p16 methylation had significantly higher risk for disease progression (P = 0.01). The relative risk for progression was 1.69 (95% CI: 1.12-2.54), and the association remained statistically significant (RR = 1.54, 95% CI: 1.01-2.34) after adjusting for clinical and pathological variables. The risk for death was also higher in methylation positive patients than in methylation negative patients (RR = 1.33, 95% CI: 0.88-2.00), but the difference was not statistically significant. CONCLUSION: The study suggests that promoter methylation in the p16 gene is associated with ovarian cancer progression, and evaluation of p16 methylation may have values in predicting ovarian cancer prognosis.

Adult↗
PubMed2004

[Spontaneous pneumothorax revealing malignant pleural mesothelioma. Three case reports].

Spontaneous pneumothorax is an uncommon inaugural presentation of malignant pleural mesothelioma. We report three cases in men aged 65, 30 and 76 years. The diagnosis was suggested at medical imaging and was confirmed at histological analysis of biopsies obtained by thoracoscopy in two patients and thoracotomy in one. The first patient (age 65 years) died two months after the initial diagnosis. The second patient (age 30 years) was alive 40 months after 15 chemotherapy cycles using a platinim-gemcitabine combination. Complete tumor response was achieved in the third patient (age 76 years) after 9 chemotherapy cycles with the same combination. Since mid-term prognosis is fatal for this type of tumor, we propose thoracoscopy in all patients over 30 years who develop spontaneous pneumothorax with no morphological features increasing the risk of pneumothorax, and particularly in patients with asbestos exposure.

Adult↗
PubMed2004

Functional expression of ATM gene carried by HSV amplicon vector in vitro and in vivo.

Ataxia-telangiectasia (AT) is a human autosomal recessive disease with a pleiotropic phenotype characterized by cerebellar degeneration, immunodeficiency, premature aging, cancer predisposition, and radiation sensitivity. The gene mutated in AT, ATM (for AT-mutated), had been cloned and found to have ionizing radiation and oxidative stress-inducible kinase activity. No treatment can stop the progression of the disease. In this study, the complete open-reading frame of ATM cDNA was cloned into a Herpes simplex virus type-1 (HSV-1) amplicon vector (pTO-ATM), and the transduction of cultured AT cells was demonstrated by immunohistochemistry and Western blot analysis. Functional gene expression was evaluated by cell colony-forming assays following exposure to oxidative stress. The survival of AT cells with ATM gene transduction was about 100% higher compared to nontransduced cells after t-butyl hydroperoxide treatments. Next, the normal ATM gene expression in different regions of the rat brain was studied. Immunohistochemistry staining demonstrated weak endogenous ATM protein expression in neurons of the caudate-putamen, with significantly higher levels of expression detected in neurons in other brain regions. Exogenous ATM gene expression from pTO-ATM after viral transduction in the caudate-putamen of the adult rat was examined. At 3 days after injection of the pTO-ATM viral vector, abundant positive ATM staining of the neurons was found at the injection sites, in comparison to the controls. These data demonstrate that the relatively large ATM cDNA can be transduced and expressed in vitro and in vivo from an HSV amplicon viral vector. These data provide initial evidence that the replacement of the ATM gene into the cells of AT patients might be possible some day.

Animals↗
PubMed2004

Real-time quantitative PCR analysis of factor XI mRNA variants in human platelets.

Coagulation factor XI (FXI) plays an essential role in blood coagulation. A deficiency of FXI is an unusual hemorrhagic diathesis in that the bleeding tendency can be highly variable, ranging from severe deficiencies with no symptoms to mild and moderate deficiencies requiring multiple blood transfusions for hemorrhages. This variability in bleeding has been attributed to a number of factors including the presence of a novel form of FXI associated with platelets, which ameliorates the bleeding in some cases of FXI deficiency. However, the nature of this platelet FXI molecule is controversial. Hsu et al. (J Biol Chem 1998; 273: 13787-93) suggest that it is a product of normal FXI - but lacking exon V whilst Martincic et al. (Blood 1999; 94: 3397-404) were unable to detect this alternatively spliced variant using RT-PCR. In order to resolve this controversy, we have employed the highly sensitive technique of real-time quantitative RT-PCR using RNA isolated from FXI-deficient patients. Our results indicate that the platelets of both normal and FXI deficient individuals contain FXI mRNA that is identical to the mRNA found in liver. An exon V deleted splice variant was not detected. Thus the FXI message is not alternatively spliced in platelets and therefore would not be able to produce an unusual FXI protein.

Alternative Splicing↗
PubMed2004

Diagnosis of genital herpes by real time PCR in routine clinical practice.

BACKGROUND: Virus isolation in cell culture is the recognised diagnostic gold standard for genital herpes. Although increasing evidence indicates that polymerase chain reaction (PCR) provides a more rapid and sensitive diagnostic method, its implementation in routine diagnostic settings has been limited by concerns over contamination and cost. OBJECTIVE: To evaluate the feasibility of replacing virus culture with PCR for the diagnosis of genital herpes in settings serving large populations of genitourinary medicine (GUM) attendees. METHODS: Genital swabs collected from 233 consecutive GUM attendees with suspected genital herpes were tested in parallel by virus culture and automated real time PCR. Three specimen preparation methods were evaluated and the assay reliability was assessed by repeat testing, comparison with a commercially available assay, and herpes simplex virus (HSV) sequence analysis. Probe melting temperatures (Tm) were used to differentiate between HSV types without additional post-PCR steps. RESULTS: HSV was detected in 79/233 (34%) samples by virus culture and 132/233 (57%) samples by PCR. PCR significantly increased HSV detection in both early (< 5 days) and late (> or = 5 days) presentations and in both first and recurrent episodes. HSV detection and typing by PCR was achieved within less than 4 hours leading to a significant reduction in labour compared to virus culture. Most specimens (120/132, 91%) were typed as HSV-2. Results were highly reproducible. CONCLUSIONS: Real time PCR is a highly reproducible, rapid, and labour efficient method for HSV detection in genital swabs. Its implementation is feasible in routine diagnostic settings.

Base Sequence↗
PubMed2004

Postnatal depression across countries and cultures: a qualitative study.

BACKGROUND: Postnatal depression seems to be a universal condition with similar rates in different countries. However, anthropologists question the cross-cultural equivalence of depression, particularly at a life stage so influenced by cultural factors. AIMS: To develop a qualitative method to explore whether postnatal depression is universally recognised, attributed and described and to enquire into people's perceptions of remedies and services for morbid states of unhappiness within the context of local services. METHOD: The study took place in 15 centres in 11 countries and drew on three groups of informants: focus groups with new mothers, interviews with fathers and grandmothers, and interviews with health professionals. Textual analysis of these three groups was conducted separately in each centre and emergent themes compared across centres. RESULTS: All centres described morbid unhappiness after childbirth comparable to postnatal depression but not all saw this as an illness remediable by health interventions. CONCLUSIONS: Although the findings of this study support the universality of a morbid state of unhappiness following childbirth, they also support concerns about the cross-cultural equivalence of postnatal depression as an illness requiring the intervention of health professionals; this has implications for future research.

Adult↗
PubMed2004

Pilot scheme for performance assessment of HIV-1 genotypic resistance testing in the UK.

HIV-1 drug susceptibility testing by genotypic methods is now widespread in the UK and it is thus important to determine the reproducibility of such investigations. A pilot study was carried out to determine the reproducibility between laboratories of genotypic testing by nucleotide sequencing of patient samples, and to compare the interpretations of the results provided to the clinicians. Samples were distributed between the participating laboratories. Eight laboratories, using three different methods, sequenced four samples. Nucleotide sequence and reports were collated and compared by one laboratory. Where sequencing data were obtained > 99% concordance was observed for nucleotide designations. No discordances in nucleotide sequencing were found in positions associated with drug resistance. However, there were considerable differences between the laboratories in the interpretation of some of the mutations with respect to their effect on drug susceptibility. This study emphasises the variability in the available interpretation systems, and the importance of joint laboratory-clinical discussion in making decisions about treatment options.

Data Interpretation, Statistical↗
PubMed2003

Laparoscopic total mesorectal excision (TME) for rectal cancer surgery: long-term outcomes.

BACKGROUND: Total mesorectal excision (TME) offers the lowest reported rates of local recurrence and the best survival results in patients with rectal cancer. However, the laparoscopic approach to resection for colorectal cancer remains controversial due to fears that oncologic principles will be compromised. We assessed the feasibility, safety and long-term outcome of laparoscopic rectal cancer resections following the principles of TME. The aim of this study was to evaluate the perioperative outcome and long-term results of laparoscopic TME. METHODS: We reviewed the prospective database of 102 consecutive unselected patients undergoing laparoscopic TME for rectal cancer between November 1991 and December 2000. Follow-up was done through office charts or direct patient contact. Recurrence and survival curves were generated by the Kaplan-Meier method. RESULTS: Laparoscopic TME was completed successfully in 99 patients, whereas conversion to an open approach was required in three cases (3%). The overall morbidity and mortality rates were 27% and 2%, respectively, with an overall anastomotic leak rate of 17%. Of the 102 patients, four were excluded from the oncologic evaluation because final pathology was not confirmatory (two had anal canal squamous cell carcinoma and two had villous adenoma with dysplasia). In 90 of the 98 remaining patients (91.8%), the resection was considered curative. The remainder had a palliative resection due to synchronous metastatic disease or locally advanced disease. Mean follow-up was 36 months (range, 6-96). There were no trocar site recurrences. The local recurrence rate was 6%, and the cancer-specific survival of all curatively resected patients was 75% at 5 years. The overall survival rate of all curatively resected patients was 65% at 5 years; mean survival time was 6.23 years (95% confidence interval [CI], 5.39-7.07). CONCLUSION: Laparoscopic TME is feasible and safe. The laparoscopic approach to the surgical treatment of operable rectal cancer does not seem to entail any oncologic disadvantages.

Adult↗
PubMed2003

Cerebrospinal fluid (CSF) and serum S100B: release and wash-out pattern.

S100B is an important brain specific protein for monitoring damage and activation of astrocytes. Using a straight forward, non-resource demanding in-house ELISA technique we measured S100B in cerebrospinal fluid (CSF) and serum in patients with traumatic brain injury (TBI) (serum), subarachnoid hemorrhage (SAH) (CSF, serum), intracranial hemorrhage (ICH) (CSF, serum), normal controls (NC) (serum) and a reference population (CSF, N=409). The release and wash-out pattern found in CSF and serum are discussed in relation to the three main determinants for increased brain specific protein levels in body fluids: (i) total mass effect; (ii) pathology; and (iii) time effect.

Adult↗
PubMed2003

Novel prion protein insert mutation associated with prolonged neurodegenerative illness.

BACKGROUND: Mutations in the prion protein gene (PRNP) are found in approximately 13 to 15% of persons classified as dying from a transmissible spongiform encephalopathy. Point and octapeptide repeat insert and deletion mutations are described in the open reading frame (ORF) of PRNP. The authors present a clinicopathologic study of a patient with a family history of a lengthy and progressive neurodegenerative disorder associated with a novel large octapeptide repeat insert mutation. METHODS: Neuropathologic examination, including immunohistochemistry for the prion protein, was undertaken. The ORF of PRNP was amplified by PCR, cloned, and sequenced. Homogenate of cerebral tissue underwent Western blot analysis for the prion protein before and after proteinase K treatment. RESULTS: The proband died after a 16-year illness commencing at age 29 years. Confident premortem clinical diagnosis was not achieved despite a brain biopsy. Autopsy examination of the brain confirmed a spongiform encephalopathy. Prion protein immunohistochemistry revealed occasional granular deposits in the cerebellar granular layer. The proband was found to harbor a novel PRNP 168 base pair (bp) insert mutation. CONCLUSION: The authors have identified a novel 168 bp octapeptide repeat insert mutation. Prion protein immunohistochemistry differs from previous cases harboring seven octapeptide repeat and other long insert mutations. Optimization of PRNP analysis, especially PCR conditions, is essential to avoid overlooking this type of mutation and delay the correct molecular genetic diagnosis.

Adult↗
PubMed2003

Serum and urine nitrate and nitrite are not reliable indicators of intrathecal nitric oxide production in acute brain injury.

This study examined the correlation between nitric oxide (NO) metabolites in the three major body fluid compartments and assessed performance of newly described vanadium-based assay for simultaneous detection of nitrite and nitrate (NO(x)) in human samples. Vanadium reduces nitrate to nitrite, which can be measured after a colorimetric reaction with Griess reagents. Cisternal cerebro spinal fluid (CSF), serum and urine samples from 10 patients with acute brain injury (ABI) were compared to control subjects. Significantly higher CSF NO(x) levels were found in brain injury patients compared to control patients (19.7+/-13.7 vs. 6.5+/-2.3 microM; p=0.01), which persisted for 10-day period of observation. The serum and urine levels of NO(x) on admission were not statistically different (42.8+/-28.2 microM; 584.1+/-337.8 micromol/g Cr, respectively) from controls (36.8+/-14.8 microM; 819.7+/-356.0 micromol/g Cr), but tended to decrease during the disease course reaching the lowest level on day 6 (serum: 19.3+/-8.4 microM, urine: 300.4+/-111.9 micromol/g Cr). CSF levels of NO(x) correlated moderately with those in serum (p=0.001, R=0.5). Serum NO(x) concentrations correlated weakly with urine levels (p=0.04, R=0.3). There was no significant correlation between CSF NO(x) and urine NO(x) levels. In conclusion, patients suffering brain injury had increased NO(x) concentrations in CSF, which remained independent from other body fluid compartments. Serum and urinary NO(x) levels cannot be used as a reliable index to assess intrathecal NO production.

Adult↗
PubMed2003

Corticosteroids for hospitalised children with acute asthma.

BACKGROUND: Systemic corticosteroids are used routinely in the management of children with severe acute asthma. There is a lack of consensus regarding the agent, dose and route of corticosteroid administration. OBJECTIVES: To determine the benefit of systemic corticosteroids (oral, intravenous, or intramuscular) compared to placebo and inhaled steroids in acute paediatric asthma. SEARCH STRATEGY: All controlled trials were identified from the Cochrane Airways Review Group Register, hand searching of respiratory journals, reference lists and contacts with experts and pharmaceutical companies. SELECTION CRITERIA: Studies were included if they described a randomised controlled trial (RCT) involving children aged 1-18 years with severe acute asthma who received oral, inhaled, intravenous or intramuscular corticosteroids. Only studies in which patients required hospital admission were included. DATA COLLECTION AND ANALYSIS: Two reviewers using a standard form extracted all data. All data, numeric calculations and graphic extrapolations were independently confirmed. MAIN RESULTS: Seven trials were included with a total of 426 children studied (274 with oral prednisone vs. placebo, 106 with intravenous steroids vs placebo and 46 with nebulised budesonide vs prednisolone). A significant number of steroid treated children were discharged early after admission (>4 hours) with an OR of 7.00 (95% CI: 2.98 to 16.45) and NNT of 3 (95%CI: 2 to 8). The length of stay was shorter in the steroid groups with a WMD of -8.75 hours (95% CI: -19.23 to 1.74). There were no significant differences between groups in pulmonary function or oxygen saturation measurements. Children treated with steroids in hospital were less likely to relapse within one to three months with OR 0.19 (95%CI: 0.07 to 0.55) and NNT of 3 (95%CI: 2 to 7). The single small study that compared nebulised budesonide to oral prednisone failed to demonstrate equivalence or a difference between each therapy. REVIEWER'S CONCLUSIONS: Systemic corticosteroids produce some improvements for children admitted to hospital with acute asthma. The benefits may include earlier discharge and fewer relapses. Inhaled or nebulised corticosteroids cannot be recommended as equivalent to systemic steroids at this time. Further studies examining differing doses and routes of administration for corticosteroids will clarify the optimal therapy.

Acute Disease↗