Impregnation of antibiotic into porous high density polyethylene material (Medpor) using negative pressure.
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Anti-Bacterial Agents↗
Biomedical subjects
R J Moore
Publications and source records attributed to R J Moore.
Comparison of bovine RNA polymerase III promoters for short hairpin RNA expression.
RNA interference (RNAi) mediated by DNA-based expression of short hairpin RNA (shRNA) is a powerful method of sequence-specific gene knockdown. A number of vectors for expression of shRNA have been developed that feature promoters from RNA polymerase III (pol III)-transcribed genes of mouse or human origin. To advance the use of RNAi as a tool for functional genomic research and for future development of specific therapeutics in the bovine species, we have developed shRNA expression vectors that feature novel bovine RNA pol III promoters. We characterized two bovine U6 small nuclear RNA (snRNA) promoters (bU6-2 and bU6-3) and a bovine 7SK snRNA promoter (b7SK). We compared the efficiency of each of these promoters to express shRNA molecules. Promoter activity was measured in the context of RNAi by targeting and suppressing the reporter gene encoding enhanced green fluorescent protein. Results show that the b7SK promoter induced the greatest level of suppression in a range of cell lines. The comparison of these bovine promoters in shRNA expression is an important component for the future development of bovine-specific RNAi-based research.
Animals↗
Degeneration of the cervical disc: histology compared with radiography and magnetic resonance imaging.
Decisions about the treatment of neck pain are largely made on the basis of information gained from plain X-rays and magnetic resonance imaging (MRI), which are used routinely as part of preliminary investigation. We performed a descriptive cadaveric study to compare histology with radiography and MRI. We correlated plain radiography, disc height [Farfan index (FI)] and MRI findings with histology to assess the ability of radiology to detect significant pathologic lesions. The study included 52 motion segments from nine subjects over the age of 50, who underwent routine hospital autopsy. Disc degeneration was assessed by histology, radiography, disc height (FI: anterior disc height plus posterior disc height divided by anterioposterior diameter) and MRI using established grading systems. Most of the discs were classified radiologically as grade 1 (19/52), grade 2 (13/52), grade 3 (9/52) or grade 4 (3/52). Eight of the discs were graded as normal. The distribution of MRI grades was grade 0 (9/36), grade 1 (9/36), grade 2 (7/36), grade 3 (8/36) and grade 4 (3/36). Half of the discs (26/52) showed advanced (grade 4) degeneration histologically. FI correlated with histological grade (P = 0.013), MRI grade (P = 0.02) and radiological grade (P < 0.001) of degeneration. Radiological and histological grade of degeneration showed a weak correlation (r = 0.3, P = 0.033). MRI correlated with overall histological grade (r = 0.41, P = 0.015, n = 34). Histological features (e.g., tears, rim lesions, prolapse of nucleus material) were poorly recognised by MRI, which had a sensitivity for disc material prolapse and annulus tears of less than 40%. Our study showed that discs from patients over 50 years are histologically severely degenerated; however, these changes may not be detected by conventional radiography and MRI.
Aged↗
A versatile system for the expression of nonmodified bacteriocins in Escherichia coli.
AIMS: To develop a method and plasmid vectors suitable for expression of class II bacteriocins from Escherichia coli. METHODS AND RESULTS: The expression vector pSuV1 was constructed by inserting the PelB secretion signal coding sequence and a number of restriction endonuclease sites for cloning, into pTYB1. Codon optimized genes encoding the active mature region of each bacteriocin were constructed and inserted into pSuV1. Transfer of these constructs to a host expressing T7 RNA polymerase allowed for expression of secreted mature or fusion forms of the bacteriocins. Generation of the fusion, to the adjacent intein-chitin-binding domain gene, was achieved by removal of a small intervening BseRI fragment. The bacteriocins BacR1, divercin V41, enterocin P, pediocin PA-1 and piscicolin 126 were expressed from this system. For piscicolin 126, expression levels of 200 microg l(-1) in the mature form and 1100 microg l(-1) when cleaved from the fusion partner were achieved. All expressed bacteriocins displayed antimicrobial activity. CONCLUSIONS: Several class II bacteriocins have been expressed in E. coli using purpose designed plasmid vectors described here. SIGNIFICANCE AND IMPACT OF THE STUDY: This method provides a common expression system capable of producing a range of different class II bacteriocins. It allows researchers to study class II bacteriocins without access to the original producer strain, the native bacteriocin gene, or highly specific heterologous producing strains. Resulting expression levels are as high or higher than those previously reported for related bacteriocins.
Bacteriocins↗
Health and well-being of farm women: contradictory roles in the contemporary economy.
To document the roles of farm women in the contemporary farm economy, their physical health and psychological well-being, and their interaction with and evaluation of the health care system, a multi-stage study employing both quantitative and qualitative research strategies was implemented. A total of 717 Canadian farm women in 20 rural Saskatchewan municipalities returned a 20-page objective questionnaire that focused on: (1) health care, (2) health status, (3) social support, (4) well-being, (5) lifestyle and activities, (6) stress, (7) work, (8) male and female roles, (9) demographics, and (10) farm issues. Subsequently, 20 qualitative interviews were conducted to explore in-depth the findings of the survey. Results document long hours of work, on and off the farm, that often went unacknowledged; pressure to assume the role of a "traditional farm wife," expectations they often felt they had difficulty living up to; and high levels of stress in response to economic and family pressures. Although rating the availability and quality of health care as "fair to good," the farm women commented on the lack of access to medical and counseling services, and a perceived lack of understanding by policymakers and professionals. Integrated health and educational service centers, increased use of nurse practitioners, and establishment of mobile health services are recommended policy initiatives.
Adult↗
A qualitative study of head and neck cancer.
The findings presented contribute to quality of life (QOL) research by highlighting the significance of factors affecting the communication by patients with primary-stage squamous cell carcinoma of the head and neck cancer (SCCHN) of their experiences of suffering after treatment to their clinicians. Qualitative research methodology based on open-ended interviews with 18 survivors of American Joint Committee on Cancer primary stage I and II SCCHN were used. The interviews were transcribed verbatim and thematically analyzed. Three important themes emerged: (1). a diminished self (2). fears of addiction, and (3). hopelessness and the loss of meaning in life after SCCHN. The findings indicate that SCCHN patients under-report their experiences mainly due to fear. As a consequence, and perhaps due to a failure on the part of clinicians and patients to adequately address such fears, SCCHN patients may experience greater psychological morbidity, becoming increasingly fatalistic about biomedicine's ability to restore them to health after cancer despite being "cured", or to relieve related symptoms. This qualitative study provides a perspective as to why such under-reporting occurs, thereby potentially enhancing clinician-patient communication and the QOL of SCCHN patients who present with curable disease.
Carcinoma, Squamous Cell↗
Functional magnetic resonance imaging (magnetization transfer) and stereological analysis of human placentae in normal pregnancy and in pre-eclampsia and intrauterine growth restriction.
Magnetic resonance imaging provides a non-invasive method for investigating functional changes in the human placenta in vivo. In this study, we combine a magnetic resonance imaging technique called magnetization transfer with established stereological methods in order to analyse and compare placentae from normal (16-36 weeks of gestation) and complicated (pre-eclampsia, intrauterine growth restriction) pregnancies. Magnetization transfer provided an in vivo measure of the ratio of bound protons:total protons and stereological analysis of histological sections was used to estimate a residual:total volume ratio (the ratio of non-vascular volume to total placental volume). Statistical comparisons were drawn using tests for related samples (longitudinal data) or one-way analysis of variance (cross-sectional data). We found no significant differences in magnetization transfer between gestational age groups or between uncomplicated pregnancies and pregnancies complicated by pre-eclampsia or intrauterine growth restriction. In comparable groups of different subjects, stereological analyses also failed to demonstrate significant differences in residual:total volume ratios. We conclude that [a] the ratio of non-vascular volume:total placental volume does not alter between 16 and 36 weeks of normal gestation, and [b] this integrated response is also conserved in pre-eclampsia and intrauterine growth restriction.
Birth Weight↗
Communicating suffering in primary stage head and neck cancer.
The findings presented in this discussion seek to make a contribution to quality of life (QOL) research, by highlighting the import of factors affecting the communication of primary stage head and neck cancer patient's experiences of suffering after treatments by their clinicians. Qualitative research methodology based on open-ended interviews with 18 survivors of American Joint Committee on Cancer (AJCC) Stage I and Stage II, squamous cell carcinoma of the head and neck (SCCHN) were used. The interviews were transcribed verbatim and thematically analysed. In this preliminary analysis, three important themes emerged: (1) a self diminished by cancer; (2) the fear of addiction to pain medications; and (3) hopelessness and the loss of meaning in life after SCCHN. Our present findings indicate that SCCHN patients understand their experiences of cancer and under-report their experiences of suffering mainly because of fear. These include fears of: being further diminished by SCCHN, fears of addiction, and an inability to cope with the additional losses associated with SCCHN. As a consequence, and perhaps, because of a failure the part of clinicians and patients to adequately address these fears, SCCHN patients may also experience greater psychological morbidity, becoming fatalistic about biomedicine's ability to restore them to health after cancer, or related symptoms, including pain, despite being 'cured.' This study provides a perspective on why this under-reporting occurs, thereby potentially enhancing clinician-patient communication and the QOL of SCCHN patients who present with curable disease.
Adult↗
Improved vectors for expression library immunization--application to Mycoplasma hyopneumoniae infection in pigs.
Expression library immunization (ELI) has previously been used in a number of disease models in mice. Here, we describe the first example of the application of ELI to a large animal model with the immunization of pigs against enzootic pneumonia, a disease caused by Mycoplasma hyopneumoniae. The development of new plasmid vectors and library screening methods facilitated the application of ELI to this disease by allowing random libraries to be screened for clones expressing recombinant proteins. In this way the vast majority of clones in random libraries that are unproductive can be eliminated, meaning that libraries are more likely to give protection and are subsequently easier to further screen and analyze. By using this approach we have used one library screen and two animal trials to progress from an original library of 20,000 clones to a group of just 96 clones.
Amino Acid Sequence↗
Vaccination against ovine footrot using a live bacterial vector to deliver basic protease antigen.
A strain of Corynebacterium pseudotuberculosis, designated Toxminus, that has been rationally attenuated by deletion of the phospholipase D gene, is being developed as a live vaccine vector for the delivery of veterinary vaccine antigens. In the present study a recombinant form of the basic protease gene of the ovine footrot causative bacterium, Dichelobacter nodosus, was introduced into the vector strain using the high copy number plasmid pEP2. This strain secreted the basic protease protein. Vaccination trials in sheep with the recombinant strain demonstrated that, although an IgG immune response was elicited, the animals were not protected from footrot following artificial challenge under pen conditions. Although the sheep were not protected there was evidence that the progression of the disease was slowed.
Animals↗
Antenatal determination of fetal brain activity in response to an acoustic stimulus using functional magnetic resonance imaging.
Functional magnetic resonance imaging (fMRI) is now a well-established technique for directly identifying adult brain activity. This study builds on earlier pilot work that showed that fMRI could provide direct evidence of fetal brain cortical activation in response to an auditory stimulus. The new work presented here aims to assess the sensitivity of this technique in a larger sample group. This article includes a specific discussion of the methodology required for fetal fMRI. Sixteen pregnant subjects were scanned between 37 and 41 weeks gestation, 12 had an auditory stimulus applied to the maternal abdomen (study group) and 4 had an auditory stimulus applied to the mother's ears (control group). Two of twelve (2/12) study-group patients experienced back pain so that the experiment was abandoned; 4/12 showed significant activation (P < 0.005) in one or both of the temporal lobes; 1/12 showed significant activation in the frontal lobe. A susceptibility artifact at the interface between the maternal bowel and the fetus affected 3/12 data sets. No significant activation was found in 3/4 of the control cases, and 1/4 could not be analyzed due to a susceptibility artifact.
Acoustic Stimulation↗
In vivo diffusion measurements as an indication of fetal lung maturation using echo planar imaging at 0.5T.
The aim of this study was twofold: First, to establish the normal range of fetal lung diffusion values measured during healthy pregnancy; and second, to determine whether fetal lung diffusion could be used as an indication of fetal lung maturity. The apparent diffusion coefficient (ADC), averaged over all 26 subjects with an average gestational age of 29 +/- 6 weeks (mean +/- sd), was found to be 2.0 +/- 0.6 x 10(-9) m(2)/sec (mean +/- sd), but a trend was found indicating that ADC increased with gestational age at the rate of 0.07 x 10(-9) m(2)/sec per week (P = 4 x 10(-5)). To determine the usefulness of this data in predicting lung maturity, a simple three-compartment model was proposed which was comprised of intra-lung amniotic fluid, intra-tissue water, and vascular blood. The relative proportions of each compartment were taken from the literature, and exchange between the compartments was assumed to be minimal. This model predicted the in vivo data reasonably well, and indicated that MR measurements of fetal lung diffusion are a marker for the degree of vascularization of the terminal tubules. Magn Reson Med 45:247-253, 2001.
Diffusion↗
High-level production of recombinant chicken interferon-gamma by Brevibacillus choshinensis.
Cytokines, such as interferon-gamma have been shown to have adjuvant and growth promoting activity in poultry and livestock and have the potential to be used as alternatives to antibiotics. We have developed an efficient system for commercial-scale synthesis of recombinant chicken interferon-gamma (ChIFN-gamma) using Brevibacillus choshinensis as the host for protein production. The ChIFN-gamma expression vector, pNCIFN, was constructed using the novel Escherichia coli-B. choshinensis shuttle vector, pNCMO2. ChIFN-gamma expression was optimized by investigating different culture conditions and different host B. choshinensis mutants. The highest level of production was observed using the B. choshinensis HPD31-MB2 strain grown at 30 degrees C, where ChIFN-gamma was produced at approximately 300-500 mg/L. ChIFN-gamma was also produced as a His-tagged fusion protein by using the pNCHis-IFN expression vector, a derivative of pNCMO2. The protein was constitutively secreted into the culture supernatant and could be partially purified in a single step using a Ni-nitrilotriacetic acid column. This recombinant His-ChIFN-gamma was shown to have the same biological activity as native ChIFN-gamma.
Affinity Labels↗
African American women and breast cancer: notes from a study of narrative.
Survival after breast cancer and after all cancers is significantly worse for African American women than for others. Although many reasons have been proposed, no studies have explored the reception of messages about breast cancer by African American survivors of this disease, and how public images and discourses about breast cancer affects both their perceived risk for this disease and their experiences of illness. Narrative accounts of their lived experiences with breast cancer were collected from 23 African American survivors of breast cancer. Three themes have emerged: (a) Breast cancer is perceived to be a white woman's disease; (b) cancer is caused by experiences of repeated traumatic heartbreak; and finally, (c) there is a perceived lack of social support and understanding for the unique life experiences of the African American survivor of breast cancer. Nurses are on the front line of patient care. In the context of the managed care environment, they spend more time with patients than other health care providers and are soundboards for many patient concerns. As such, they can use the information provided in this study to inform high-risk women, current patients, partners, and other individuals in the medical community of how African American women might inaccurately access their personal risks for breast cancer, despite the public emphasis on this disease. Through the use of culturally sensitive pamphlets, nurses and other medical practitioners can also open discussions with underserved and minority patients as a means of realistically addressing some of these women's fears about breast cancer. These fears are barriers to effective cancer prevention because these individuals may consciously or unconsciously link a diagnosis of breast cancer, or even behaviors related to cancer prevention, to a potential death sentence.
Adaptation, Psychological↗
Effect of meal viscosity and nutrients on satiety, intragastric dilution, and emptying assessed by MRI.
The relationship between the intragastric distribution, dilution, and emptying of meals and satiety was studied using noninvasive magnetic resonance imaging techniques in 12 healthy subjects with four polysaccharide test meals of varying viscosity and nutrient content as follows: 1) low-viscosity nonnutrient, 2) low-viscosity nutrient, 3) high-viscosity nonnutrient, and 4) high-viscosity nutrient. Increasing the nutrient content of the high-viscosity meal delayed gastric emptying from 46 +/- 9 to 76 +/- 6 min (P < 0.004), whereas increasing viscosity had a smaller effect. The volume of secretions within the stomach 60 min after ingestion was higher for the high-viscosity nutrient meal (P < 0.04). A simple model to calculate the total volume of secretion added to the test meal is presented. Color-coded dilution map images showed the heterogeneous process of progressive gastric dilution of high-viscosity meals, whereas low-viscosity meals were uniformly diluted. Fullness was found to be linearly related to total gastric volumes for the nutrient meals (R(2) = 0.98) and logarithmically related for the nonnutrient meals (R(2) = 0.96). Fullness was higher for high- compared with low-viscosity meals (P < 0.02), and with the nutrient meals this was associated with greater antral volumes (P < 0.05).
Adult↗
Antiangiogenic and antitumor activities of cyclooxygenase-2 inhibitors.
We provide evidence that cyclooxygenase (COX)-2-derived prostaglandins contribute to tumor growth by inducing newly formed blood vessels (neoangiogenesis) that sustain tumor cell viability and growth. COX-2 is expressed within human tumor neovasculature as well as in neoplastic cells present in human colon, breast, prostate, and lung cancer biopsy tissue. COX-1 is broadly distributed in normal, as well as in neoplastic, tissues. The contribution of COX-2 to human tumor growth was indicated by the ability of celecoxib, an agent that inhibits the COX-2 enzyme, to suppress growth of lung and colon tumors implanted into recipient mice. Mechanistically, celecoxib demonstrated a potent antiangiogenic activity. In a rat model of angiogenesis, we observe that corneal blood vessel formation is suppressed by celecoxib, but not by a COX-1 inhibitor. These and other data indicate that COX-2 and COX-2-derived prostaglandins may play a major role in development of cancer through numerous biochemical mechanisms, including stimulation of tumor cell growth and neovascularization. The ability of celecoxib to block angiogenesis and suppress tumor growth suggests a novel application of this anti-inflammatory drug in the treatment of human cancer.
Animals↗
Agonist-stimulated [35S]GTPgammaS binding in brain modulation by endogenous adenosine.
Coupling of receptors to G-proteins can be assessed by the ability of specific agonists to stimulate [35S]GTPgammaS binding in both brain membranes and sections in the presence of excess GDP. In some brain regions, however, high basal activity makes it difficult to detect agonist-stimulated [35S]GTPgammaS binding. The present study suggests a modification of the assay to reduce basal [35S]GTPgammaS binding and thus increase the signal:noise ratio. Adenosine A1 receptors belong to the class of G-protein-coupled receptors that activate Gi/Go proteins in brain. In the present study, the A1 agonist R(-)N6-(2-phenylisopropyl)adenosine (R-PIA) stimulated [35S]GTPgammaS binding in brain regions known to contain A1 receptors, including cerebellum, hippocampus and dentate gyrus, medial geniculate body, superior colliculus, certain thalamic nuclei, cerebral cortex, piriform cortex, caudate-putamen, and nucleus accumbens. Treatment of sections and membranes with adenosine deaminase (ADase), which is typically used in adenosine assays to eliminate endogenous adenosine, reduced basal [35S]GTPgammaS binding. In addition, for cannabinoid and mu-opioid agonists, the percent stimulation of [35S]GTPgammaS binding was approximately doubled when ADase was included in the assay. These results suggest that endogenous adenosine contributes significantly to basal [35S]GTPgammaS binding in certain brain regions, and that this activity may be reduced by the addition of ADase, thus improving the signal:noise ratio of agonist-stimulated [35S]GTPgammaS binding.
Adenosine↗
In vivo intravoxel incoherent motion measurements in the human placenta using echo-planar imaging at 0.5 T.
This paper presents the first in vivo measurements of intravoxel incoherent motion in the human placenta, obtained using the pulsed gradient spin echo (PGSE) sequence. The aims of this study were two-fold. The first was to provide an initial estimate of the values of the IVIM parameters in this organ, which are currently unknown. The second aim was then to use these results to optimize the sequence timings for future studies. The moving blood fraction (f), diffusion coefficient (D), and pseudo-diffusion coefficient (D*) were measured. The average value of f was 26 +/- 6 % (mean +/- SD), D was 1.7 +/- 0.5 x 10(-3) mm2/sec, and D* was 57 +/- 41 x 10(-3) mm2/sec. For the optimized values of b, the expected percentage uncertainty in the fitted values of f, D, and D* for the placenta were sigmaf/f = 14.9%, sigmaD/D = 14.3%, sigmaD*/D* = 44.9%, for an image signal-to-noise of 20:1, and a total imaging time of 800 sec.
Analysis of Variance↗