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Biomedical subjects

B L Smith

Publications and source records attributed to B L Smith.

At least 181 records · Page 10Linked to original sources
PubMed1991

Facial eczema in goats: the toxicity of sporidesmin in goats and its pathology.

Groups of six goats were orally dosed with sporidesmin at rates of 0.3, 0.6, 1.2 and 2.4 mg of sporidesmin per kg body weight and their responses up to 6 weeks later compared with those of sheep dosed at the same time. Clinical facial eczema and pathological lesions similar to those found in sheep were found in all the goat breeds, but at higher dose rates of sporidesmin than those which caused equivalent lesions in sheep. Saanens were the most susceptible goat breed, requiring 2-4 times as much sporidesmin as sheep to achieve similar effects. G4 and feral goats required 4-8 times the sheep dose of sporidesmin to obtain similar responses. Gamma-glutamyltransferase reached its highest serum levels after 20 days while glutamate dehydrogenase and aspartate aminotransferase reached their highest levels between 10 and 20 days. Alkaline phosphatase did not rise consistently to high levels in affected goats. The elevation in aspartate aminotransferase levels tended to be early and transient; glutamate dehydrogenase early and prolonged; gamma-glutamyltransferase late and prolonged, and'alkaline phosphatase late and minor. There was considerable individual variation in the time at which elevations occurred and the levels which enzymes reached. Cholesterol and bilirubin levels were high if liver injury was severe.

Journal Article↗
PubMed1991

Adrenal-associated changes in experimental sporidesmin poisoning of sheep.

Sporidesmin-dosed hoggets which developed photosensitisation were shown to have enlarged adrenal glands and premature involution of the thymus. These sheep also developed high concentrations of plasma cortisol after the onset of photosensitisation. Sporidesmin-dosed sheep which did not show photosensitisation showed less or no adrenal associated changes.

Journal Article↗
PubMed1991

Ectoparasites from elk (Cervus elaphus nelsoni) from Wyoming.

Hides of nine elk, collected during the winter of 1986-1987 from the National Elk Refuge, Wyoming (USA) were examined for ectoparasites. Parasites recovered were mites, Psoroptes sp. (five elk); lice, Solenopotes ferrisi and Bovicola (Bovicola) longicornis (seven elk); and winter ticks, Dermacentor albipictus (nine elk). Three elk with severe scabies had an estimated 0.6 x 10(6), 3.8 x 10(6) and 6.5 x 10(6) mites, respectively. Densities of mites were much higher in skin regions with severe dermatitis. Skin lesions on elk with scabies consisted of dense, often moist, scabs extending along the dorsal and lateral thoracic regions of the body. Lesions attributed to winter ticks consisted of broken hair and alopecia on the dorsal portion of the lower neck, often extending in a "collar" around the neck.

Animals↗
PubMed1991

Use of orthopedic markers for quantitative determination of proximal radial and ulnar growth in foals.

Cortical bone screws were implanted into the proximal portion of the right and left radius and ulna of 6 newborn Quarter Horse foals as radiographic markers for measurement of growth. Distance between markers on a lateral radiographic view was measured. Radiographs were taken at 2-week intervals until the horses were 8 weeks old, at 4-week intervals until they were 48 weeks old, and at 12-week intervals until they were 72 weeks old. The proximal radius and ulna grew at similar rates during the 72-week period of evaluation, and growth continued throughout 72 weeks. The proximal radius grew 3.5 cm, and the ulna grew 3.4 cm. Although the rates of growth were similar, growth from the ulnar physis contributed only to the length of the olecranon; growth was not transmitted to the ulnar diaphysis distal to the cubital joint. The proximal radius slid distally in relation to the ulna as growth occurred at the proximal radial physis. These findings suggest that transfixing the ulna to the radius while growth is occurring at the proximal radial physis impedes the natural shifting process, and subluxation of the elbow can result. Severity of subluxation would be inversely related to the age of the horse at the time of transfixation.

Analysis of Variance↗
PubMed1991

Performance of techniques used to detect drugs of abuse in urine: study based on external quality assessment.

Twenty-five samples of lyophilized urine from the U.K. External Quality Assessment Scheme for Drugs of Abuse were analyzed by an average of 95 laboratories between April 1987 and December 1989. Samples contained mixtures of analytes and included replicated concentrations of morphine, methadone, amphetamine, and cocaine at 0, 1, 2, and 5 mg/L and of benzoylecgonine at 0, 0.4, 1, 2, and 4 mg/L. Some chromatographic techniques were inadequate for detecting morphine, amphetamine, cocaine, and benzoylecgonine at the lower concentrations of analytes studied: gas-liquid chromatography was least sensitive for morphine; in-house thin-layer chromatography (TLC) was least sensitive for the other analytes. Few significant differences in specificity were detected between techniques, although significant interference from structurally related compounds was demonstrated in assays of morphine, methadone, and amphetamine. Exceptions were the Boehringer (BCL) test for opiates and TLC applied to amphetamine and benzoylecgonine, which demonstrated considerable lack of specificity.

Amphetamine↗
PubMed1991

Portable data acquisition cart for equine transportation stress study.

A remote data sampling cart has been designed and built for studying environmental factors that produce stress in horses during transportation. This dedicated sampling cart uses an XT-compatible mother board powered by a 12 V battery, with customized BIOS and ROM program. Sampling is performed using two digital and eight A/D (bipolar, differential) channels in burst mode at a frequency of 1 kHz. Digitized data are stored on magnetic tape for retrieval after the experiment. Configuration of sampling parameters is accomplished via a serial communications link to a host computer, and is stored in battery backed-up RAM, so that the cart can be self initializing. The digitized data consist of samples from transducers that measure 3-axis accelerations, air flow, sound intensity, environmental temperatures, and heart rates of two horses. Twenty four digital output lines control external sampling devices to collect gas samples for quantification and identification of airborne particles, noxious gas concentrations, and airborne microbes. The sampling cart has been used in an initial study of the effects of tethering position (head forward vs. head backward) on heart rates in horses being trailered, and in continuing studies designed to modify the transport environment to minimize stress imposed on animals during transit.

Animals↗
PubMed1990

Results of conservative surgery and radiation therapy for breast cancer.

For stage I or II breast cancer, conservative surgery and radiation therapy are as effective as modified radical or radical mastectomy. In most cases, cosmetic considerations and the availability of therapy are the primary concerns. The extent of a surgical resection less than a mastectomy has not been a subject of a randomized trial and is controversial. It appears that removal of a quadrant of the breast for small lesions is safe but excessive. Using histologic findings in the biopsy as a guide, it may be possible to limit the breast resection to gross tumor removal for most patients while using wider resections for patients with an extensive intraductal component or for invasive lobular carcinoma. It also appears that excluding patients from breast conservation on the basis of positive margins on the first attempt at tumor excision may be unnecessarily restrictive. Although patients with an extensive intraductal component or invasive lobular carcinoma should have negative margins, it appears that a patient with predominantly invasive ductal carcinoma can be treated without re-excision if all gross tumor has been resected and there is no reason to suspect extensive microscopic disease. Patients with indeterminate margins should have a re-excision. Axillary dissection provides prognostic information and prevents progression of the disease within the axilla. Axillary dissections limited to level I will accurately identify a substantial number of patients who have pathologically positive but clinically negative nodes. When combined with radiation therapy to the axilla, a level I dissection results in a limited number of patients with progressive axillary disease. Patients with pathologically positive axillas and patients at particularly high risk for systemic disease because of the extent of axillary node involvement can be identified by dissections of levels I and II. Radiation therapy can be avoided safely in patients who have pathologically negative axillas by level I and II dissection. There appears to be no advantage to routine dissection of level III lymph nodes. Lymphedema of the arm and breast increases with more extensive dissections and with radiation therapy.

Axilla↗
PubMed1990

Potential space and the Rorschach: an application of object relations theory.

This article examines the concept of potential space, developed by Winnicott (1971), and its relevance for Rorschach assessment. I propose that the response process can be viewed as occurring in the potential space between reality and fantasy and that various forms of psychopathology can be conceptualized as forms of the collapse of potential space. I suggest that this model can be of utility in interpreting the Rorschach protocols of a variety of difficult-to-diagnose patients. Examples from the Rorschach of a patient diagnosed with a dissociative disorder are presented to illustrate these points.

Arousal↗
PubMed1990

Perception of intraphonemic differences by phoneticians, musicians, and inexperienced listeners.

Several studies have shown that extensive training with synthetic speech sounds can result in substantial improvements in listeners' perception of intraphonemic differences. The purpose of the present study was to investigate the effects of listening experience on the perception of intraphonemic differences in the absence of specific training with the synthetic speech sounds being tested. Phonetically trained listeners, musicians, and untrained listeners were tested on a two-choice identification task, a three-choice identification task, and an ABX discrimination task using a synthetic [bi]-[phi] continuum and a synthetic [wei]-[rei] continuum. The three-choice identification task included the identification of stimuli with an "indefinite" or "ambiguous" quality in addition to clear instances of the opposing phonetic categories. Results included: (1) All three subject groups showed some ability to identify ambiguous stimuli; (2) phonetically trained listeners were better at identifying ambiguous stimuli than musicians and untrained listeners; (3) phonetically trained listeners performed better on the discrimination task than musicians and untrained listeners; (4) musicians and untrained listeners did not differ on any of the listening tasks; and (5) participation by the inexperienced listeners in a 10-week introductory phonetics course did not result in improvements in either the three-choice identification task or the discrimination task.

Adult↗
PubMed1990

A survey of drugs of abuse testing by clinical laboratories in the United Kingdom. Steering Committee for the UK-External Quality Assessment Scheme for Therapeutic Drug Assays.

An external quality assessment survey of testing facilities in UK clinical laboratories for the detection of drugs of abuse was made with nine freeze-dried samples of urine containing representative drugs with their metabolites from the following seven classes; amphetamines and stimulants, barbiturates, cannabinoids, cocaine, minor tranquillisers, opiates and non-opiate narcotics. Reports were received from 120 laboratories. Thirty six per cent of laboratories reported on all seven drug classes and 71% on the five classes excluding cannabinoids and cocaine. A single drug screening technique was used by 32% of laboratories whilst 46% were able to perform tests by both immunological and chromatographic techniques. There was a mean level of false positive reporting of 4.3% and an observed level of false negative reports of 8.4%, the latter underestimating the true frequency. The minor tranquillisers, cocaine and benzoyl ecgonine were the most frequently missed analytes. Several false reports had important potential implications for patient care.

Central Nervous System Agents↗
PubMed1989

Malignant seminoma in a cryptorchid stallion.

A 16-year-old cryptorchid Quarter House with colic had a large, lobulated soft-tissue mass to the left of the pelvic inlet. At surgery, 2 large multilobulated pedunculated masses were removed. A large blood vessel enveloped by one of the masses was damaged, and the horse exsanguinated. Postmortem examination of the abdomen revealed the masses to be malignant seminoma, with multiple sites of metastasis.

Animals↗
PubMed1989

Method for determining vertebral body positions in the sagittal plane using skin markers.

A method by which the location of vertebral bodies can be estimated from the external profile of the spine in the sagittal plane is described. The technique involves a normalization of the curve from T1 to L5 and approximation using a cubic spline. Mapping functions are developed that enable the transformation of a skin profile to a vertebral centroid curve. Data were obtained for 13 subjects between the ages of 13 and 17 who had undergone lateral spinal radiographs with radiopaque skin markers over the vertebral spinal processes. Results suggested that vertebral body centroids could be estimated from the skin profile to a precision having a standard error of the estimate of 0.4 cm. This was improved to 0.2 cm if the lumbar curve were considered separately.

Humans↗
PubMed1989

Evaluation of difloxacin in the treatment of uncomplicated urethral gonorrhea in men.

Difloxacin is a new quinolone antimicrobial agent with in vitro activity against both Neisseria gonorrhoeae and Chlamydia trachomatis and a long (26-h) half-life. A single oral dose of 200 mg of difloxacin was used to treat 30 men with uncomplicated urethral gonorrhea in an open trial. Of the isolates of N. gonorrhoeae, three produced penicillinase and two were resistant to tetracycline. N. gonorrhoeae was eradicated from all 29 evaluable patients. The geometric mean MIC of difloxacin for 30 pretreatment N. gonorrhoeae isolates was 0.014 (range, less than or equal to 0.0039 to 0.03) microgram/ml. Four (13.3%) of the 30 subjects with gonococcal urethritis also had C. trachomatis recovered from their pretreatment cultures. Treatment with difloxacin was associated with the eradication of C. trachomatis from all four men. In addition, C. trachomatis was isolated from the posttreatment culture of only one man who had a negative culture before treatment. Nineteen patients (65.5%) reported adverse experiences, and 17 of them (58.6%) developed symptoms suggestive of central nervous system dysfunction. An oral dose of 200 mg of difloxacin is effective treatment for uncomplicated urethral gonorrhea and may also eliminate a coexisting infection with C. trachomatis. Side effects may limit the utility of this agent.

Adult↗