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Biomedical subjects

K Wilson

Publications and source records attributed to K Wilson.

At least 109 records · Page 6Linked to original sources
PubMed1999

Cholinergic neurons of the pelvic autonomic ganglia and uterus of the female rat: distribution of axons and presence of muscarinic receptors.

Acetylcholine (ACh) stimulates contraction of the uterus and dilates the uterine arterial supply. Uterine cholinergic nerves arise from the paracervical ganglia and were, in the past, characterized based on acetylcholinesterase (AChE) histochemistry. However, the histochemical reaction for acetylcholinesterase provides only indirect evidence of acetylcholine location and is a nonspecific marker for cholinergic nerves. The present study: (1) reevaluated cholinergic neurons of the paracervical ganglia, (2) examined the cholinergic innervation of the uterus by using retrograde axonal tracing and antibodies against molecules specific to cholinergic neurons, choline acetyltransferase and the vesicular acetylcholine transporter, and (3) examined muscarinic receptors in the paracervical ganglia using autoradiography and a radiolabeled agonist. Most ganglionic neurons were choline acetyltransferase- and vesicular acetylcholine transporter-immunoreactive and were apposed by choline acetyltransferase/vesicular acetylcholine transporter-immunoreactive terminals. Retrograde tracing showed that some cholinergic neurons projected axons to the uterus. These nerves formed moderately dense plexuses in the myometrium, cervical smooth muscle and microarterial system of the uterine horns and cervix. Finally, the paracervical ganglia contain muscarinic receptors. These results clearly reveal the cholinergic innervation of the uterus and cervix, a source of these nerves, and demonstrate the muscarinic receptor content of the paracervical ganglia. Cholinergic nerves could play significant roles in the control of uterine myometrium and vasculature.

Acetylcholinesterase↗
PubMed1999

Calretinin-immunoreactive nerves in the uterus, pelvic autonomic ganglia, lumbosacral dorsal root ganglia and lumbosacral spinal cord.

Nerves containing the calcium-binding protein calretinin have been reported in several organs but not in female reproductive organs and associated ganglia. This study was undertaken to determine if nerves associated with the uterus contain calretinin and the source(s) of calretinin-synthesizing nerves in the rat (are they sensory, efferent, or both?). Calretinin-immunoreactive nerves were present in the uterine horns and cervix where they were associated with arteries, uterine smooth muscle, glands, and the epithelium. Calretinin-immunoreactive terminals were apposed to neurons in the paracervical ganglia; in addition, some postganglionic neurons in this ganglion were calretinin positive. Calretinin perikarya were present in the lumbosacral dorsal root ganglia, no-dose ganglia, and lumbosacral spinal cord. Retrograde axonal tracing, utilizing Fluorogold injected into the uterus or paracervical parasympathetic ganglia, revealed calretinin-positive/Fluorogold-labeled neurons in the dorsal root and nodose ganglia. Also, capsaicin treatment substantially reduced the calretinin-positive fibers in the uterus and pelvic ganglia, thus indicating the sensory nature of these fibers. The presence of calretinin immunoreactivity identifies a subset of nerves that are involved in innervation of the pelvic viscera and have origins from lumbosacral dorsal root ganglia and vagal nodose ganglia. Though the exact function of calretinin in these nerves is not currently known, calretinin is likely to play a role in calcium regulation and their function.

Animals↗
PubMed1999

Help seeking behaviour and health and social services utilisation by people suffering from urinary incontinence.

It is estimated that urinary incontinence can effect up to 23% of the population at some time during their adult years, with 9% currently experiencing symptoms. This study found that the majority of sufferers had spoken to or had contacted their GP about their incontinence, and that people currently suffering from incontinence were significantly more likely to have seen their GP within the last month than those who were continent. Help seeking behaviour was also influenced by the severity of incontinence, with people suffering from severe incontinence significantly more likely to have sought help than those with light to moderate incontinence. Two thirds of sufferers who did not seek help were too embarrassed to do so. Significantly more people who were incontinent that did not seek help in a health authority without an established continence service did not know that health services were available, compared with those in a health authority having an established continence service. It is important for health care providers to ensure that the public knows what services are on offer and how to access them. Significantly more incontinence sufferers in the health authority with an established continence service chose not to seek help from a health professional compared with those in the health authority without service, which could indicate there was an element of informed choice in not accessing the services available. Significantly more people who were incontinent than continent required help with their activities of daily living and personal self care. They were also significantly more likely than those who were continent to require formal and informal contacts provided by health services, local authority, the church or voluntary sector. It is important that people suffering from incontinence have their health and social needs assessed so that services can be effectively targeted.

Activities of Daily Living↗
PubMed1999

The relationship between abdominal aortic aneurysm wall compliance, maximum diameter and growth rate.

AIM: Aortic compliance as measured by the pressure-strain elastic modulus (Ep) and stiffness (beta), may allow a more precise estimate of rupture risk. The aim of this study was to determine the relationships between compliance, maximal aneurysm diameter and growth rate. METHODS: Sixty abdominal aortic aneurysm patients of median age 73 years, were studied. Growth rate was derived from repeat ultrasound scans obtained over a median period of 21 months (range 6-48). At the end of follow-up, patients underwent measurement of maximum aortic diameter, Ep and beta using the Diamove echo-tracking system. RESULTS: Growth rate correlated positively (r = 0.6, P < 0.01) with maximum diameter on entry to the study There was a positive correlation between mean arterial pressure and Ep (r = 0.3, P = 0.03), but not between mean arterial pressure and beta (r = 0.8, P = 0.61). A positive correlation was found between final maximum diameter and Ep (r = 0.22, P = 0.04) but not beta (r = 0.16, P = 0.11). There was no significant relationship between growth rate and Ep or beta. CONCLUSION: Large aneurysms tended to be less compliant. Within a population of abdominal aortic aneurysm of similar maximum diameter there was a 10-fold variation in Ep and beta. Compliance and growth rate were not related. If aortic compliance is related to risk of rupture then this predictive information is likely to be largely independent of that currently obtained from size and growth rate.

Aged↗
PubMed1999

Adenovirus-mediated gene transfer of the beta2-adrenergic receptor to donor hearts enhances cardiac function.

Gene transfer to modify donor heart function during transplantation has significant therapeutic implications. Recent studies by our laboratory in transgenic mice have shown that overexpression of beta2-adrenergic receptors (beta2-ARs) leads to significantly enhanced cardiac function. Thus, we investigated the functional consequences of adenovirus-mediated gene transfer of the human beta2-AR in a rat heterotopic heart transplant model. Donor hearts received 1 ml of solution containing 1 x 1010 p.f.u. of adenovirus encoding the beta2-AR or an empty adenovirus as a control. Five days after transplantation, basal left ventricular (LV) pressure was measured using an isolated, isovolumic heart perfusion apparatus. A subset of hearts was stimulated with the beta2-AR agonist, zinterol. Treatment with the beta2-AR virus resulted in global myocardial gene transfer with a six-fold increase in mean beta-AR density which corresponded to a significant increase in basal contractility (LV + dP/dtmax, control: 3152.1 +/- 286 versus beta2-AR, 6250.6* +/- 432.5 mmHg/s; n = 10, *P < 0.02). beta2-AR overexpressing hearts also had higher contractility after zinterol administration compared with control hearts. Our results indicate that myocardial function of the transplanted heart can be enhanced by the adenovirus-mediated delivery of beta2-ARs. Thus, genetic manipulation may offer a novel therapeutic strategy to improve donor heart function in the post- operative setting.

Adenoviridae↗
PubMed1999

Hepatitis C antibody detection in dried blood spots.

In the UK, there have been few studies of the seroprevalence of antibodies to hepatitis C virus (anti-HCV). As part of an ongoing prevalence study of HCV in injecting drug users, we have developed a technique for detecting anti-HCV in blood spots dried on filter paper using a commercially available assay. Subjects with and without serum anti-HCV were studied. The manufacturer's recommended cut-off (CO) for a positive anti-HCV result is kit-dependent, and therefore a ratio of test result (T) to kit CO was used to standardize results. T/CO values greater than 0.99 had a sensitivity of 100% and a specificity of 87.5% for anti-HCV detection. T/CO values greater than 1.99 had a sensitivity of 97.2% and a specificity of 100%. Hence, testing dried blood spots may be useful for detecting anti-HCV in epidemiological studies and as a diagnostic test in patients with poor peripheral venous access.

Blood Specimen Collection↗
PubMed1999

Utility of hepatocytes to model species differences in the metabolism of loxtidine and to predict pharmacokinetic parameters in rat, dog and man.

1. The metabolism of loxtidine (1-methyl-5-[3-[3-[(1-piperidinyl) methyl] phenoxy] propyl] amino-1H-1,2,4-triazole-3-methanol) was studied in freshly isolated rat, dog and human hepatocytes. Metabolism in vitro was comparable with previously available in vivo data in all three species with the marked species differences observed in vivo being reproduced in the hepatocyte model. 2. The major route for the metabolism of loxtidine by rat hepatocytes was N-dealkylation to form the propionic acid and hydroxymethyl triazole metabolites. A minor metabolic route was the oxidation of loxtidine to a carboxylic acid metabolite. The major route of metabolism for loxtidine in dog hepatocytes was glucuronidation with oxidation to the carboxylic acid metabolite being of minor importance. Incubation of loxtidine with human hepatocytes resulted in the drug remaining largely unchanged but with the carboxylic acid metabolite being produced in minor amounts. 3. In vitro studies were undertaken with rat, dog and human hepatocytes to determine the Michaelis-Menten parameters Vmax and Km for the sum of all the metabolic pathways. These kinetic parameters were used to calculate the intrinsic clearance of loxtidine. Using appropriate scaling factors, the predicted in vivo hepatic clearance was then calculated. The predicted intrinsic clearances were 51.4 +/- 12.4, 8.0 +/- 0.8 and 1.0 +/- 0.6 ml/min/kg for rat, dog and human hepatocytes respectively. These data were then used to calculate hepatic clearances of 24.5, 3.1 and 0.2 ml/min/kg for rat, dog and man respectively. 4. In vivo hepatic and intrinsic clearances for loxtidine were determined in rat, dog and human volunteers. The hepatic clearances of loxtidine were 26.6, 6.6 and 0.4 ml/min/kg in rat, dog and man respectively and intrinsic clearances were 58.5, 18.6 and 2.0 ml/min/kg in rat, dog and man respectively. 5. The present studies demonstrate that the hepatocyte model may be a valuable in vitro tool for predicting both qualitative and quantitative aspects of the metabolism of a drug in animals and man at an early stage of the drug development process.

Adult↗
PubMed1999

Stability of questionnaire items in sport and exercise psychology: bootstrap limits of agreement.

We describe an alternative method for assessing the stability of individual questionnaire items in sport and exercise psychology. To date, the Pearson product-moment correlation coefficient has been widely used in psychometrics. We propose an alternative non-parametric method based on proportion of agreement. Ninety-two male university students completed the revised 9-item Social Physique Anxiety Scale on two occasions, separated by a 2-week interval. Point estimates of the proportion of direct within-individual agreement between the two occasions were calculated separately for each item of the Social Physique Anxiety Scale. Estimates of uncertainty of the agreement were calculated using a bootstrapping resampling technique. For each item, 2000 bootstrap samples (each n = 92 pairs) were redrawn from the original sample. The sample statistic was calculated for each bootstrap sample to provide a bootstrap sampling distribution. The 95% confidence intervals (CI) were then calculated using the percentile method. The three most problematic items were items 7, 8 and 10 (as labelled in the original 12-item scale). These items demonstrated an agreement of 0.46 (95% CI= 0.36 0.56), 0.42 (95% CI = 0.33-0.52) and 0.41 (95% CI = 0.32-0.51) respectively. Our proposed method measures absolute agreement between test-retest responses, is free of normal assumptions, does not depend on high between-individuals variance, and can be applied successfully to individual items in the development of psychological tests.

Adult↗
PubMed1999

Crystallization and preliminary diffraction data analysis of both single and pseudo-merohedrally twinned crystals of rubredoxin oxygen oxidoreductase from Desulfovibrio gigas.

Crystals of rubredoxin oxygen oxidoreductase have been obtained and characterized. They belong to space group P2(1)2(1)2, with unit-cell dimensions a = 88.24 (15), b = 101.25 (7), c = 90.80 (3) A. The homodimer (86 kDa) in the asymmetric unit is related by a non-crystallographic twofold rotation axis parallel to the ab 'diagonal' direction, as shown by the self-rotation maximum in the section with chi = 180 degrees. This pseudo-crystallographic symmetry element was also found to be the twinning axis of pseudo-merohedrally twinned crystals, leading to apparent pseudo-tetragonal P42(1)2 crystal symmetry.

Cold Temperature↗
PubMed1999

Effect of stretching duration on active and passive range of motion in the lower extremity.

OBJECTIVES: To investigate the effect of different durations of stretching (five or 15 seconds) on active and passive range of motion (ROM) in the lower extremity during a five week flexibility training programme. METHOD: Twenty four university sport club members (19 men, five women), with a mean (SD) age of 20.5 (1.35) years, were randomly assigned to one of three groups (two treatment and one control). The two treatment groups participated in a static active stretching programme three times a week for a five week period, holding each stretch for a duration of either five or 15 seconds. The total amount of time spent in a stretched position was controlled. The five second group performed each stretch nine times and the 15 second group three times resulting in a total stretching time of 45 seconds for both groups for each exercise. The control group did not stretch. Active and passive ROM were determined during left hip flexion, left knee flexion, and left knee extension before and after the training programme using an inclinometer. RESULTS: Two factor within subject analysis of variance indicated no significant difference in ROM before and after the training programme for the control group. However, significant improvements in active and passive ROM (p < 0.05) were shown in both treatment groups after the five week training programme. Two factor analysis of variance with repeated measures and post hoc analysis showed significant differences between the treatment groups and the control group for the improvements observed in active (p < 0.05) and passive (p < 0.05) ROM. The five and 15 second treatment groups did not differ from one another when ROM was assessed passively, but significant differences were apparent for active ROM, with the 15 second group showing significantly greater improvements (p < 0.05) than the five second group. CONCLUSION: These findings suggest that holding stretches for 15 seconds, as opposed to five seconds, may result in greater improvements in active ROM. However, sustaining a stretch may not significantly affect the improvements gained in passive ROM.

Adult↗
PubMed1999

Comparing pediatric intentional injury surveillance data with data from publicly available sources: consequences for a public health response to violence.

OBJECTIVE: A hospital based intentional injury surveillance system for youth (aged 3-18) was compared with other publicly available sources of information on youth violence. The comparison addressed whether locally conducted surveillance provides data that are sufficiently more complete, detailed, and timely that clinicians and public health practitioners interested in youth violence prevention would find surveillance worth conducting. SETTING: The Boston Emergency Department Surveillance (BEDS) project was conducted at Boston Medical Center and the Children's Hospital, Boston. METHOD: MEDLINE and other databases were searched for data sources that report separate data for youth and data on intentional injury. Sources that met these criteria (one national and three local) were then compared with BEDS data. Comparisons were made in the following categories: age, gender, victim-offender relationship, injury circumstance, geographic location, weapon rates, and violent injury rates. RESULTS: Of 14 sources dealing with violence, only four met inclusion criteria. Each source provided useful breakdowns for age and gender; however, only the BEDS data were able to demonstrate that 32.6% of intentional injuries occurred among youth aged 12 and under. Comparison data sources provided less detail regarding the victim-offender relationship, injury circumstance, and weapon use. Comparison of violent injury rates showed the difficulties for practitioners estimating intentional injury from sources based on arrest data, crime victim data, or weapon related injury. CONCLUSIONS: Comparison suggests that surveillance is more complete, detailed, and timely than publicly available sources of data. Clinicians and public health practitioners should consider developing similar systems.

Adolescent↗
PubMed1999

A simple, inexpensive method for teaching how membrane potentials are generated.

We have developed a simple laboratory exercise that uses an inexpensive dialysis membrane (molecular weight cutoff = 100) to illustrate the generation of membrane potentials (Vm) across plasma membranes of animal cells. A piece of membrane approximately 2.0 cm2 is mounted in an Ussing-like chamber. One chamber half is designated cytosol and the other half external. Chamber sidedness helps students relate their findings to those of real cells. As in real cells, outward directed K+ concentration gradients [high cytosolic K+ concentration ([K+]c) and low extracellular K+ concentration] generate cytosol electrically negative Vm with a slope of approximately -45 mV/decade change in [K+]c. The polarity of Vm reflects the outward flow of potassium ions because flow of the larger counterion, H2PO4-, is restricted to the pores in the membrane. A slope less than Nernstian (<59 mV/decade) suggests that the membrane is slightly permeable to H2PO4-. Importantly, this facilitates teaching the use of the Nernst equation to quantify the relationship between ion concentration ratios across membranes and magnitude of Vm. For example, students use their data and calculate a permeability ratio PK/PH2PO4 that corresponds to a slope of approximately 24% less than Nernstian. This calculation shows that Nernstian slopes are achieved only when permeability to the counterion is zero. Finally, students use the concept of membrane capacitance to calculate the number of ions that cross the membrane. They learn where these ions are located and why the bulk solutions conform to the principle of electroneutrality.

Animals↗
PubMed1999

The snoring spectrum: acoustic assessment of snoring sound intensity in 1,139 individuals undergoing polysomnography.

STUDY OBJECTIVES: To quantify the snoring sound intensity levels generated by individuals during polysomnographic testing and to examine the relationships between acoustic, polysomnographic, and clinical variables. DESIGN: The prospective acquisition of acoustic and polysomnographic data with a retrospective medical chart review. SETTING: A sleep laboratory at a primary care hospital. PARTICIPANTS: All 1,139 of the patients referred to the sleep laboratory for polysomnographic testing from 1980 to 1994. INTERVENTIONS: The acoustic measurement of snoring sound intensity during sleep concurrent with polysomnographic testing. MEASUREMENTS AND RESULTS: Four decibel levels were derived from snoring sound intensity recordings. L1, L5, and L10 are measures of the sound pressure measurement in decibels employing the A-weighting network that yields the response of the human ear exceeded, respectively, for 1, 5, and 10% of the test period. The Leq is a measure of the A-weighted average intensity of a fluctuating acoustic signal over the total test period. L10 levels above 55 dBA were exceeded by 12.3% of the patients. The average levels of snoring sound intensity were significantly higher for men than for women. The levels of snoring sound intensity were associated significantly with the following: polysomnographic testing results, including the respiratory disturbance index (RDI), sleep latency, and the percentage of slow-wave sleep; demographic factors, including gender and body mass; and clinical factors, including snoring history, hypersomnolence, and breathing stoppage. Men with a body mass index of > 30 and an average snoring sound intensity of > 38 dBA were 4.1 times more likely to have an RDI of > 10. CONCLUSIONS: Snoring sound intensity levels are related to a number of demographic, clinical, and polysomnographic test results. Snoring sound intensity is closely related to apnea/hypopnea during sleep. The noise generated by snoring can disturb or disrupt a snorer's sleep, as well as the sleep of a bed partner.

Adult↗
PubMed1999

The teaching and learning principles of metropolitan Aborigines with diabetes.

This study was undertaken at a leading Aboriginal health agency in Adelaide called Nunkuwarrin Yunti (King & Wilson 1998). One of the aims not previously reported involved identifying the way that metropolitan Aborigines prefer to learn about their diabetes management. An ethnographic approach was used to interview ten Aboriginal health professionals and four clients (n = 14) about this topic. The results indicated the worldview held by metropolitan Aborigines about diabetes health care, the Aboriginal learner, beliefs about teaching and learning, the characteristics of an effective teacher and a suggested teaching plan.

Adult↗
PubMed1998

Crystallization and preliminary X-ray crystallographic studies of the plant aspartic proteinase cardosin A.

The plant aspartic proteinase cardosin A was crystallized using vapour diffusion. Crystals belong to the monoclinic space group C2, cell dimensions a = 116.9 (2), b = 87.2 (8), c = 81.3 (1) A, beta = 104.4 (4) degrees, and contain two molecules in the asymmetric unit related by a non-crystallographic twofold axis. Diffraction data were collected at room temperature with radiation from a synchrotron source up to 2.85 A resolution. When the crystals were flash cooled to 110 K in a nitrogen stream the same resolution limit could also be obtained on a rotating-anode source. Recently, synchrotron radiation together with flash cooling led to an improvement of the diffraction data to 1.72 A resolution.

Aspartic Acid Endopeptidases↗
PubMed1998

Interleukin-10 gene transfer inhibits murine mammary tumors and elevates nitric oxide.

Transfection of cDNA for IL-10 into line 66.1 murine mammary tumor cells results in marked suppression of tumor growth and metastasis. Others have reported that nitric oxide has potent antitumor activity and IL-10 is known to regulate the inducible isoform of nitric oxide synthase (iNOS) expressed in macrophages. We identified nitric oxide production in mammary tumors as indicated by electron paramagnetic resonance detection of nitric oxide-hemoglobin (NO-Hb). IL-10 expression resulted in elevated levels of NO-Hb in mammary tumors. Immunohistochemical examination of mammary tumors for iNOS protein revealed few positively staining cells in parental or control neo-transfected tumors but strong iNOS staining in all IL-10 transfected tumors, consistent with the NO-Hb data. To determine if mammary epithelial tumor cells themselves, express nitric oxide synthase activity, cultured tumor cells were treated with pro-inflammatory cytokines and nitrite accumulation was assessed in the conditioned medium. All IL-10 producing cell lines accumulated uM concentrations of nitrite in response to short term (24 hr) cytokine stimulation. Cells not expressing IL-10 (parental and neo-transfectants) accumulated no nitrite under similar culture conditions. After longer stimulation (48 hr), parental and 66-neo cells accumulated lower amounts of nitrite. IL-10 gene transfer is associated with increased iNOS protein expression and enzymatic activity detected both in vitro and in vivo. Our findings suggest that the antimetastatic and antitumor activity of IL-10 is related to enhanced production of nitric oxide.

Adenocarcinoma↗