Biomedical subjects
S Newman
Publications and source records attributed to S Newman.
Characterization of DNA polymorphisms in three populations of hereford cattle and their associations with growth and maternal EPD in line 1 herefords.
Three populations of Hereford cattle differing in inbreeding levels and genetic potential for growth were genotyped for seven DNA polymorphisms. The populations were compared to determine differences in allele frequency and genetic variation. Significant differences in allele frequency among the populations were found at six of the seven polymorphisms genotyped, and average genetic variation differed as expected when inbreeding levels were considered. Effects of several polymorphisms on growth and maternal EPD were evaluated for one population (Miles City Line 1 Herefords) using regression analysis. Substitution of a B allele for an A allele of the kappa-casein polymorphism accounted for significant decreases in direct birth weight and maternal 180-d gain from birth to weaning EPD explaining 15% and 8%, respectively, of EPD variability. Several other significant effects accounting for small portions of EPD variability were also detected.
Toxic effects of surgical glove powders on the eye.
Surgical gloves are commonly coated with dusting powders that have severe toxic effects on the eye. Talcum powder causes a chronic granulomatous reaction with fibrosis and adhesion formation. Cornstarch has also been shown to cause a granulomatous reaction as well as sterile endophthalmitis. These complications are preventable by the use of powder-free gloves.
Cerebral functional deficit in cardiac surgical patients investigated with P300 and neuropsychological tests.
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Sports medicine and coaching inseparable interests for Vancouver physician.
Dr. Doug Clement of Vancouver has devoted his career to sports medicine and the development of athletes. The former Olympic athlete keeps busy as codirector of the Sports Medicine Clinic and professor of medicine at the University of British Columbia, and as coach and mentor to several world-class runners.
Comparison of gamma scintigraphy and a pharmacokinetic technique for assessing pulmonary deposition of terbutaline sulphate delivered by pressurized metered dose inhaler.
A comparison has been made of pulmonary deposition of terbutaline sulphate from a pressurized metered dose inhaler (pMDI), measured in 8 healthy male subjects by gamma scintigraphy and by a pharmacokinetic (charcoal-block) method, involving drug recovery in urine. Measurements were carried out with a pMDI at slow (27 l/min) and fast (151 l/min) inhaled flows and with Nebuhaler large volume spacer device (average inhaled flow 17 l/min). Overall, the two methods did not differ significantly in their estimates of whole lung deposition, although values obtained by gamma scintigraphy exceeded those from the charcoal-block method for the pMDI with fast inhalation. The regional distribution of drug within the lungs and deposition in the oropharynx could be assessed by gamma scintigraphy, but not by the charcoal-block method. It is concluded that either method may be used to assess whole lung deposition of terbutaline sulphate from pMDIs, both with and without a spacer, although each method has its own inherent advantages and disadvantages.
Patient expectations: what do primary care patients want from the GP and how far does meeting expectations affect patient satisfaction?
There is growing recognition of the importance of patients' expectations in general practice. This study aimed to investigate the types of expectations adult primary care patients have prior to consulting the GP, and how far meeting expectations is associated with increased satisfaction. Patients (n = 504) attending general practitioners (n = 25) at 10 London general practices were included in the study. The Patients Intentions Questionnaire (PIQ) was administered prior to the consultation to investigate patients' expectations and the Expectations Met Questionnaire (EMQ) was administered after the consultation to find out what the patient reportedly obtained. Satisfaction with the consultation was also measured using the Medical Interview Satisfaction Scale (MISS). The results of a principal components analysis of PIQ item scores indicated that the most wanted items were for 'explanation of the problem'. There was less desire for 'support' or 'tests and diagnosis'. Many of the 'support' items could potentially be provided to all patients, yet a proportion of patients reported not receiving these items from the GP. The results of one-way ANOVAs revealed that patients with greater numbers of their expectations met reported significantly higher satisfaction with the consultation than those with lower numbers met. The PIQ and EMQ could be potentially useful self-audit tools for use by general practitioners and trainee GPs.
Fast stress and rest acquisitions for technetium-99m-sestamibi separate-day SPECT.
UNLABELLED: Abbreviated acquisition protocols were designed for stress and rest to decrease stress and rest SPECT image acquisition times but maintain the high count density of 99mTc-sestamibi separate-day cardiac images. METHODS: Scan findings were compared visually and quantitatively with standard SPECT for 12 rest and 32 stress patient studies. RESULTS: Of 29 stress defects detected by standard SPECT, 27 were present with the fast technique; of 8 resting SPECT defects, all were detected with fast SPECT. Two stress and no resting false-positive defects occurred with fast SPECT. Linear correlations (r) between standard and fast quantitative defect extent and severity were 0.76 and 0.86, respectively for stress SPECT, and 0.88 and 0.96 for rest SPECT. Stress fast defects were slightly less severe (p = 0.02) than those observed using standard acquisition. CONCLUSION: We conclude that these fast protocols for separate-day 99mTc-MIBI SPECT accurately detect and characterize perfusion defects and provide a means to improve patient tolerance and increase laboratory throughput.
Despite warnings, lure of steroids too strong for some young Canadians.
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Magnetic resonance imaging and neuropsychological changes after coronary artery bypass graft surgery: preliminary findings.
Cerebral morbidity is a problem after cardiac surgery. Although neuropsychological tests and imaging techniques have been applied to cardiac patients, the relationship between them has not been considered. In the preliminary investigation, we studied 15 patients (11 male, mean age 59 years) having coronary artery bypass graft (CABG) surgery. Before surgery, patients had magnetic resonance (MR) imaging and neuropsychological assessment with a battery of 10 tests. During surgery, cardiopulmonary bypass was maintained at 28 degrees C with a flow rate of 2.4 L/m2/min-1 and at a mean arterial pressure of 50-70 mm Hg. Bubble or membrane oxygenators with in-line filters were used. Arterial blood gases were maintained using a pH-stat protocol. Fourteen of the 15 patients showed MR abnormalities before surgery. One week after surgery, four patients had additional MR changes. Six patients had significant postoperative neuropsychological deficit in memory (verbal and nonverbal) and attention. The four patients with new MR abnormalities all had significant neuropsychological deficit. In addition to corroborating previous observations that a high proportion of patients undergoing elective CABG have MR abnormalities before surgery, these preliminary data suggest a promising concordance between structural brain changes and cerebral function after CABG.
Serial MRI of the brain in asymptomatic patients infected with HIV: results from the UCMSM/Medical Research Council neurology cohort.
Seventy-six homosexual or bisexual men underwent two cranial MRI studies at a mean interval of 13 months; 23 were HIV seronegative, 41 seropositive but asymptomatic (Center for Disease Control (CDC) groups II/III), and 12 had AIDS related complex (ARC)/AIDS (CDC group IV). Agreement between two neuroradiologists was rated as very good for assessment of enlargement of ventricles and good for widening of cerebral sulci and the presence of focal lesions. For assessment of serial studies, the agreement was moderate. The prevalence of cerebral atrophy and focal white matter lesions was no higher in the asymptomatic patients (CDC group II/III) than in appropriate seronegative controls. Some patients with ARC/AIDS showed evidence of developing cerebral atrophy during the study period when serial scans were compared. The imaging evidence supports the other data obtained from this cohort, which suggest that no significant CNS involvement occurs in HIV infection before the development of ARC/AIDS.
The impact of microemboli during cardiopulmonary bypass on neuropsychological functioning.
BACKGROUND AND PURPOSE: Microemboli have been implicated in the etiology of neuropsychological deficits after cardiopulmonary bypass. This study examined the incidence of high-intensity transcranial signals (microemboli) and their relation to changes in neuropsychological performance after surgery. METHODS: Transcranial Doppler ultrasonography was used to measure middle cerebral artery blood flow velocity and detect microemboli. The number of high-intensity transcranial signals was determined and related to a neurological examination and absolute changes in neuropsychological performance as well as the number of patients considered to exhibit a neuropsychological deficit. Data were available on 100 consenting patients undergoing routine cardiopulmonary bypass. Fifty of the patients were randomly assigned to a procedure that included a 40-microns arterial line filter, and 50 had the procedure without any arterial line filter. RESULTS: Significantly more patients were found to have neuropsychological deficits in the group without the arterial line filter at both 8 days (P < .05) and 8 weeks (P < .03) after surgery. In addition, more "soft" neurological signs were found in the nonfiltered group 24 hours after surgery (P < .05). More high-intensity transcranial signals were found in the nonfiltered group, and the number of high-intensity transcranial signals was found to be related to the likelihood of a patient having a neuropsychological deficit at 8 weeks. CONCLUSIONS: These data suggest that neuropsychological deficits after routine cardiopulmonary bypass are related to the number of microemboli delivered during surgery. Furthermore, the numbers of microemboli may be reduced by including a 40-microns filter on the arterial line.
Genetic analysis of calving date in Miles City Line 1 Hereford cattle.
A model for genetic analysis of calving date was proposed and variance components, genetic trends, and fixed effects for calving date were estimated in the Miles City Line 1 Hereford cattle population. There were 951 pedigree records that predated 1935, when data collection began, and 4,692 subsequent recorded calving dates through 1989. The statistical model included fixed linear continuous effects for inbreeding of calf and inbreeding of dam, discrete fixed effects for year, sex of calf, and age and previous parity of dam, and random sources of variation for individual (calf) and maternal additive genetic effects, and environmental effects of dams, mating groups, and residuals. All effects were estimated simultaneously by derivative-free procedures for REML. Male calves were born 1.58 +/- .40 d later than female calves. Cows failing to wean a calf in the previous year calved 2.81 +/- .81 d earlier than cows that had weaned a calf. Other fixed effects were small. Variance components (d2) were 23.0 for individual additive genetic effects, 5.8 for maternal additive genetic effects, 9.2 for maternal permanent environmental effects, 11.8 for contemporary group effects, and 161.3 for residual effects. Environmental trend was +.17 d/yr and individual additive genetic trend was -.07 d/yr. No maternal additive genetic trend was detected. These results do not encourage the use of calving day as a selection criterion for improving fertility of beef cattle.
Quantitative- and molecular-genetic effects on animal well-being: adaptive mechanisms.
Domestic farm animals play an important role in meeting some basic needs of humankind, especially food and clothing. The aspects of genetic improvement programs in livestock production pertinent to animal welfare and animal well-being are reviewed. A link is made between the evolutionary processes of adaptation and domestication and animal well-being. Animal behavior is a component of all these. Thus, the genetics of behavior may provide clues to the well-being of farm animal populations, and it will also be of relevance to public opinion issues of animal welfare. Many expressions of behavior by domestic livestock may be influenced by those processes that change gene as well as genotypic frequencies such as inbreeding, drift, and artificial selection. The environment in which the individual lives will also play a role, along with the interaction between genotype and environment. Selection for or against such behaviors as aggressiveness, docility, response to stress, and certain sexual behaviors in some livestock species has often been successful. This points to the existence of additive genetic variation for behavior, and scope for the inclusion of behavioral traits into selection programs, if these measures are shown to be related to welfare. Negative relationships between behaviors associated with well-being and traits of economic importance have been reported in most livestock species. However, estimates of genetic parameters, especially genetic correlations between objective measures of well-being and production traits, are scarce. There have been no comprehensive studies of the welfare of transgenic animals reported in the scientific literature. Increased use of biotechnology in animal agriculture, coupled with greater public scrutiny of livestock industries, may precipitate decisions concerning the interface of behavior and genetics that need to be addressed before scientists can conduct appropriate experimental evaluations.
Breeding for profit: synergism between genetic improvement and livestock production (a review).
Fifty years of research in animal breeding and genetics are examined from four perspectives: 1) genetic prediction, 2) animal testing and selection schemes, 3) dissemination of genetic improvement, and 4) definition of breeding objectives in economic form. Breeding in all classes of livestock has moved from a purebred appearance orientation to a performance (either purebred or crossbred) orientation. Unfortunately, the evolution from a performance orientation to an economic orientation is incomplete, especially for some livestock classes. Placing breeding objectives into a mathematical form on a sound economic basis is key to integrating modern developments in animal breeding into more purposeful industry programs. Procedures used to develop such objectives are reviewed with attention to common approaches. Where consensus is reached about a breeding objective (in economic form) for a class of livestock, this objective can be used in conjunction with genetic predictions to rank animals within a breeding population. Ranking without undue attention to herd of origin facilitates a pyramid-shaped hierarchy of animals that can be fundamental to the functioning of breeding enterprises contributing improvements to operations concerned with production. Genetic improvements should flow from proven genetically superior animals to improved production systems. The tiers of the pyramid need to be organized relative to animals with differing levels of economic evaluation.
Systemic lupus erythematosus--disease activity, severity, treatment and costs.
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A study of water flow efficiency in dental air/water syringe tips after repeated chemiclave sterilization.
In response to the need for dental office asepsis, many practitioners sterilize dental air/water syringe tips for each patient. It is hypothesized that repeated sterilization would lead to internal corrosion restricting the water flow. This study was conducted to evaluate consistency of water flow in a series of dental air/water syringe tips after multiple cycles of Chemiclave sterilization. An apparatus was constructed to deliver water at the same pressure and flow to each syringe tip. The flow rates between tips were significantly different (P < .001). Average water flow, in grams per minute, was determined by ten repeat trials for each tip. The tips were retested after 1, 5, and 25 cycles of Chemiclave sterilization. None of tips showed a decrease in water flow efficiency after repeated sterilization cycles. No difference in ability to remove etchant from enamel and dentin could be demonstrated using a 10-second wash.
Pamphlet on HIV and athletes dispels myths about possibility of infection through sports.
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