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Biomedical subjects

J C Wright

Publications and source records attributed to J C Wright.

At least 55 records · Page 3Linked to original sources
PubMed1997

Profile of electrodiagnostic abnormalities in cats with GM1 gangliosidosis.

OBJECTIVE: To determine which electrodiagnostic tests yield abnormal findings in cats with GM1 gangliosidosis, and to determine the approximate age of onset of electrodiagnostic abnormalities. ANIMALS: Cats (28 to 335 days old) affected with GM1 gangliosidosis (n = 11) and unaffected controls (n = 14). PROCEDURE: Cats were grouped by age: group 1, < or = 90 days, group 2, 91 to 200 days; and group 3, > 200 days. Electrodiagnostic tests were conducted, including needle electromyography, motor and sensory nerve conduction velocity, spinal evoked potentials, and brainstem auditory evoked potentials. Results for control and affected cats were compared, using the general linear model for ANOVA and Scheffé's test for multiple comparisons. RESULTS: Needle electromyography did not reveal abnormal spontaneous activity in skeletal muscles of any cat; furthermore, statistical analysis did not indicate significant difference between affected and control groups for nerve conduction velocity, confirming that degeneration of peripheral nerve fibers is not a feature of this disease. However, spinal evoked potentials were abnormal in group-3 cats; conduction velocity within sensory pathways in the cranial part of the spinal cord was significantly slower in GM1-affected cats (P = 0.0002). Brainstem auditory evoked responses also were abnormal: wave V (generated in the region of the pons) had prolonged latency in cats of groups 2 and 3 (P = 0.0003 and 0.0001, respectively, at 90 decibels sound pressure level). In the oldest cats, latencies for earlier waves within the auditory pathway also were prolonged; wave I (generated by the cochlear nerve) was prolonged in group-3 cats (P = 0.0423). CONCLUSIONS: Motor and sensory nerve conduction velocities remained within normal limits in GM1-affected cats. However, spinal evoked potentials indicated slowing in conduction velocity along the cranial part of the spinal cord in group 3 cats. Brainstem auditory evoked responses indicated prolonged latencies in cats of groups 2 and 3.

Animals↗
PubMed1997

Assessment of current techniques for determining tracheal luminal stenosis in dogs.

OBJECTIVE: To assess the accuracy of current antemortem and postmortem techniques for determining tracheal luminal stenosis. ANIMALS: 15 dogs. PROCEDURE: Percentage of tracheal luminal stenosis (PTLS) was determined by 6 methods, using measurements obtained by radiography, tracheoscopy, and necropsy after selected tracheostomy techniques were performed. To calculate PTLS, dorsoventral tracheal diameter was measured from preoperative and postoperative lateral cervical radiographic views. Preoperative or normal tracheal segments adjacent to the stenotic area were used to obtain normal tracheal diameter measurements. Planimetrically determined cross-sectional area (CSA), obtained from pre- and postoperative tracheoscopic photographs, was used to calculate PTLS. The CSA of tracheal specimens obtained at necropsy was determined, using the formula for an ellipse. Percentage of luminal stenosis was calculated, using CSA of the stenotic site and of segments craniad and caudad to the site obtained at necropsy or at surgery. All methods were compared with the control method of planimetrically determined CSA of sections obtained at necropsy of the tracheostomy and segments craniad and caudad to the site. RESULTS: Correlation was poor for radiographic and tracheoscopic techniques (r = 0.146 to 0.458, P > 0.05) The formula for an ellipse accurately predicted PTLS when measurements obtained at surgery (r = 0.516, P = 0.049) or segments craniad and caudad (r = 0.853, P < 0.001) to the site were used. CONCLUSION: Antemortem methods of assessing PTLS did not correlate with control planimetric methods. Methods using CSA determined by tracheal diameter were weakly correlated to control planimetric techniques. CLINICAL RELEVANCE: Accurate measurement of the degree of tracheal stenosis cannot be made in clinical patients using current techniques.

Animals↗
PubMed1996

Further validation of a multiplex STR system for use in routine forensic identity testing.

A polymerase chain reaction- (PCR) based short tandem repeat (STR) system has recently been developed for use in routine forensic identity testing. The methodology involves the simultaneous amplification of alleles at four loci on different chromosomes, followed by the fluorescent detection of products using an automated DNA sequencer. The adoption of this technology into operational casework offers several advantages over systems currently in use, particularly the ability to obtain results from very old or small samples, reduced operator time when compared with conventional DNA (single locus probe) analysis and the potential for automation. Validation studies were incorporated into the development work on this system. The scope of these studies has been extended by further investigation carried out in this laboratory to test the reliability of the system under normal operational procedures. It was demonstrated that the precision of size determination was sufficient for the discrimination of alleles and size windows for allelic designation were established. A collaborative exercise carried out in conjunction with two independent laboratories demonstrated the robustness of allelic designation. Having tested both the DNA quantification and amplification techniques against DNA samples from a wide range of animal and microbial species, it was confirmed that results are only obtained from higher primate DNA. The PCR methodology was tested with both simulated and real casework samples (over 250 in total). Reportable results were obtained from most items yielding extracted DNA. Approximately 20% of the casework items from which no grouping (ABO, PGM) nor SLP results were obtained, gave reportable STR results. A method for the routine purification of DNA extracts which failed to amplify was established and validated for use in forensic casework. The STR multiplex system developed by Kimpton et al. proved robust and reliable when tested under the operational procedures in place in this laboratory.

Animals↗
PubMed1996

Psychological problems following minor head injury: a prospective study.

Fifty people admitted to hospital with a predominantly minor head injury were interviewed six months and three years later. As a group, they showed evidence of post-traumatic stress disorder consistent with the DSM-III-R (American Psychiatric Association, 1987) definition, and psychological distress as measured by the Impact of Event scale and the General Health Questionnaire. In addition, changes in self-concept were measured and a prominent theme emerged of the discontinuity in the participants' sense of self following the head injury. These changes showed a significant relationship with psychological symptoms. Occupational and social functioning of the participants is also reported. It is suggested that disturbance and change following minor head injury is common and can be chronic.

Adolescent↗
PubMed1996

Novel indirect fluorescent antibody test for Lyme disease.

An indirect fluorescent antibody (IFA) test was developed using a novel format of Borrelia burgdorferi organisms adhered to a monolayer of cultured endothelial cells derived from an equine tumor. Sensitivity and specificity of the new IFA test for detecting anti-B, burgdorferi antibodies were evaluated using sera from dogs inoculated with live B. burgdorferi or vaccinated with B. burgdorferi bacterin or leptobacterins and from unvaccinated specific-pathogen-free (SPF) dogs. To compare the new IFA test with existing tests, serum samples were submitted to independent laboratories to be tested by enzyme-linked immunosorbent assay (ELISA) and a traditional IFA test. Samples were also tested with 2 commercially available membrane-bound ELISA kits. Both Borrelia-inoculated dogs and dogs vaccinated with B. burgdorferi bacterin developed levels of antibody detectable by the new IFA test. Dogs vaccinated with a combination canine vaccine or leptobacterin for food animal use developed detectable levels of antibody against Leptospira but remained seronegative for Borrelia by the new IFA test, as did the unvaccinated SPF dogs. The new IFA test was sensitive, detecting antibodies against B. burgdorferi as early as 7 days postinoculation. It was also specific, showing no cross-reactivity with anti-Leptospira antibodies induced by vaccination with leptobacterins. The new IFA test compared favorably with both the standardized traditional IFA test and ELISA. Results from both membrane-bound ELISA kits were not consistent when compared with each other or with the new IFA test. The new IFA test had low nonspecific fluorescence, which made it easier to evaluate and reduced the human error and variability of test results.

Animals↗
PubMed1996

Clues to depression in primary care practice.

Depression is a common but highly treatable mood disorder. Unfortunately, two thirds of depressed patients may never receive appropriate intervention. Because of individual and societal barriers to the diagnosis, depressive symptoms often go unrecognized. However, primary care physicians are in a unique position to surmount these obstacles by being alert to manifestations of the disorder. Treatment with antidepressant drugs, psychotherapy, electroconvulsive therapy, or a combination of these is very efficacious. The choice of method is based on such factors as history of previous response, severity of disease, concomitant medical illness, and patient preference.

Antidepressive Agents↗
PubMed1996

Effect of locally injected medications on healing of pad wounds in dogs.

OBJECTIVE: To ascertain the effects of locally injected immunostimulant and tripeptide-copper complex (TCC) on improving healing of pad wounds. DESIGN: Wounds in pads of large dogs were injected with either medication or physiologic saline solution (controls). Healing was evaluated. ANIMALS: 12 mature English Pointers. PROCEDURE: Full-thickness 6 x 8-mm wounds in metatarsal and third and fourth digital pads were injected with immunostimulant or TCC at 0, 3, and 6 days after wounding. Wounds on control dogs were injected with physiologic saline solution. Using planimetric measurements at 0, 3, 6, 14, and 21 days, rates of healing were evaluated. Biopsy of the digital pad wounds at 3, 6, and 14 days was used to evaluate collagen content by hydroxyproline analysis. Biopsy specimens were also evaluated for type-I and type-III collagen, using Sirius red differential staining. RESULTS: Effect on healing rate and hydroxyproline content was best during the first week for immunostimulant. Immunostimulant- and TCC-injected wounds had more type-I collagen than did controls at 6 days; TCC-injected wounds had the most type-I collagen. At 14 days, the amount of type-I collagen in TCC-injected wounds was significantly greater than that in other wounds. CONCLUSIONS: Tested medications had positive effects on healing of pad wounds. CLINICAL RELEVANCE: Intralesional injection of medications helps ensure their presence for enhancement of wound healing. The benefit could be lost with topical use in a bandage if the bandage is lost or becomes wet.

Adjuvants, Immunologic↗
PubMed1995

Security of attachment in 8-12-year-olds: a revised version of the Separation Anxiety Test, its psychometric properties and clinical interpretation.

This study examined the reliability and validity of an adapted version of the Separation Anxiety Test (SAT) for 8-12-year-old children. Clinical (N = 21) and nonclinical (N = 21) participants were compared on responses to the SAT coded using the Seattle scoring indices. Inter-rater reliability was established at an acceptable level, however, test-retest reliability and internal test construction were less satisfactory. Sample comparisons found the clinical participants described themselves as less securely attached and more avoidant of emotional expression than the control participants. The indices of attachment security were also related to various socioemotional aspects of functioning. In addition, the results indicated that describing "self" as different from a similar "other" child was significantly related to parental reports of poor social competence. Results are discussed in relation to an Attachment Theory framework as well as from a clinical perspective.

Anxiety, Separation↗
PubMed1995

Computed tomographic morphometry of the lumbosacral spine of dogs.

In a 5-year prospective study, computed tomographic (CT) morphometry of the lumbosacral vertebral canal was performed on 42 large-breed dogs (21 controls and 21 dogs with lumbosacral stenosis). Dogs were allotted to 4 groups. Group 1 (n = 13) consisted of cadaver specimens obtained from dogs that died or were euthanatized for reasons unrelated to the spine; group 2 (n = 8) consisted of live dogs with no history of clinical signs related to the spine and with normal neurologic examination findings; group 3 (n = 10) consisted of dogs with surgically confirmed lumbosacral stenosis; and group 4 (n = 11) consisted of dogs with suspected lumbosacral stenosis that were managed conservatively. The CT scans were performed, using 5-mm contiguous slices obtained perpendicular to the vertebral canal, from the midbody of the 5th lumbar vertebra through the caudal endplate of the sacrum (L5-S3). Lumbosacral lordosis was minimized in all dogs by positioning them in dorsal recumbency with the hind limbs flexed. A tuberculin syringe calibration phantom was placed within the scanning field of view, parallel to the axis of the spine. In each dog, 11 CT slice locations within the lumbosacral spine were evaluated. At each slice location, sagittal plane diameter, dorsal plane diameter, and transverse area of the vertebral canal, vertebral body, and calibration phantom were measured, using the CT computer's software programs for distance and area calculation. Window/level settings were constant, and all measurements were made by the same operator (JCJ). Accuracy of calibration phantom CT measurements was 100% for sagittal and dorsal plane diameter and was 85% for transverse area.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Prolonged gestation, decreased triiodothyronine concentration, and thyroid gland histomorphologic features in newborn foals of mares grazing Acremonion coenophialum-infected fescue.

Newborn foals of mares grazing on Acremonium coenophialum-infected fescue pasture throughout gestation or from gestation day 300 to parturition had increased gestation duration and decreased serum triiodothyronine concentration. Pregnant mares were allotted to 4 treatments: grazing continuously on endophyte-free (E-) fescue, grazing continuously on endophyte-infected (E+) fescue, grazing on E+ fescue from gestation day 300 to parturition, and grazing on E+ fescue from conception to gestation day 300. Morphometric studies indicated that foals born to mares exposed to endophyte late in gestation had large, distended thyroid follicles lined by flat cuboidal epithelial cells. Mean triiodothyronine concentration in foals exposed to endophyte (395.2 ng/dl) was decreased (P < 0.01), compared with mean values in control foals (778.0 ng/dl). Thyroxine and reverse triiodothyronine concentrations were not significantly different among groups. Foal organ weight as a percentage of foal body weight was not significantly different among experimental groups.

Acremonium↗
PubMed1995

Occupational portrayals on television: children's role schemata, career aspirations, and perceptions of reality.

UNLABELLED: Do children's schemata for occupations they observe in real life differ from those they see on TV? 177 second- and fifth-graders were assigned to conditions in a 2 (real-life or on TV) x 2 (police officer or nurse) design. They answered open-ended questions about what police officers or nurses do (in real life or on TV) and rated the typicality of various job activities. Their schematic knowledge about TV and real occupations was clearly differentiated. TV versions entailed more glamour, higher income, more stereotypes, and more dramatic events without negative consequences. Real-life occupations entailed more effort, status, and excitement. Older children differentiated slightly more clearly than younger ones. Children who perceived television as factual and realistic had real-world schemata similar to TV images. Children who were heavy viewers and perceived television as realistic were most likely to aspire to jobs shown on TV. CONCLUSION: children form separate schemata for social information acquired from TV and from real-world experience, but those who perceive television as socially realistic are apt to incorporate TV messages in their schemata and their aspirations.

Aspirations, Psychological↗
PubMed1995

Comparison of maternal blood and fetal liver selenium concentrations in cattle in California.

Selenium concentration was measured in paired maternal blood samples and fetal liver specimens collected at a San Joaquin County, Calif, slaughterhouse (beef = 19, dairy = 54) and from bovine aborted fetuses submitted to the California Veterinary Diagnostic Laboratory System (CVDLS; beef = 20, dairy = 20). Of the slaughterhouse samples and specimens, dairy maternal blood selenium concentration was significantly (P < 0.001) higher (mean +/- SD; 0.22 +/- 0.056 microgram/ml) than that for beef breeds (0.137 +/- 0.082 microgram/ml). The CVDLS mean maternal blood selenium concentration for the dairy-breed samples (0.192 +/- 0.028 microgram/ml) was similar to that for the slaughterhouse dairy-breed samples, but was greater than that for the slaughterhouse beef-breed samples. Slaughterhouse mean fetal liver selenium content also was higher (P < 0.001) for the dairy breeds (0.777 +/- 0.408 microgram/g), compared with the beef breeds (0.443 +/- 0.038 microgram/g). Mean fetal liver selenium content for slaughterhouse specimens was higher (P < 0.002) than that for the CVDLS specimens (beef, 0.244 +/- 0.149 microgram/g; dairy, 0.390 +/- 0.165 microgram/g). At the CVDLS, dairy fetal liver content was greater (P < 0.001) than that for beef breeds. Mean ratio of fetal liver selenium content to maternal blood selenium concentration was 3.53 +/- 1.89 for dairy breeds at the slaughterhouse (liver-to-blood correlation [r] = 0.38), and was 2.11 +/- 1.00 for dairy breeds at the CVDLS (r = 0.31) and 3.43 +/- 1.50 for beef breeds (r = 0.58). Both slaughterhouse breed ratios were significantly (P < 0.002) greater than the CVDLS dairy-breed ratio. On the basis of these results, breed and source location should be taken into account when interpreting selenium values. Fetal liver selenium content should only be used as a screening test and combined with whole blood selenium concentration from clinically normal herdmates to evaluate herd selenium status.

Abattoirs↗
PubMed1994

Concomitant brainstem axonal dystrophy and necrotizing myopathy in vitamin E-deficient rats.

The purpose of this study was to simultaneously evaluate in rats the effects of vitamin E depletion on tissue alpha-tocopherol (alpha-T) concentrations, electrophysiologic measurements and histopathology. Rats (21-day-old male Wistar) were fed either vitamin E-deficient or supplemented (control) diets (n = 6/group) for 10, 16, and 61 weeks. At these times, electrophysiologic tests (electromyography, spinal and somatosensory evoked potentials, and motor nerve conduction velocity) were performed, the rats were killed and alpha-T concentrations of adipose tissue, sciatic nerve, and cervical and lumbar spinal cord were measured along with histopathologic evaluation of skeletal muscles and the nervous system. By 61 weeks, depletion of alpha-T from adipose tissue and peripheral nerve was more severe (< 1% of controls) than from cervical and lumbar spinal cord (15 and 8% of controls, respectively). Electrophysiologic tests were normal at all times. Histopathologic evaluation at 61 weeks revealed normal peripheral nerve structure, but necrosis of type 1 muscle fibers and increased numbers of spheroids in the gracile and cuneate nuclei. Our results confirm that low alpha-T concentrations in tissues precede histologic changes in peripheral nerves and skeletal muscle. Furthermore, pathologic changes associated with vitamin E deficiency occur independently in muscle and nervous tissue of rats.

Adipose Tissue↗
PubMed1994

Noncytopathic bovine viral diarrhea virus in a system for in vitro production of bovine embryos.

Techniques for in vitro production of bovine embryos have evolved to the extent that applications for the commercial production of calves have been proposed. However, little is known about the epidemiological implications of the procedures. One concern is the introduction of noncytopathic bovine viral diarrhea virus (BVDV). In this study, follicular oocytes (n=247) collected from 10 cows were matured and fertilized in vitro and presumptive zygotes were cultured for 7 d. Primary cultures of bovine oviductal epithelial cells for use during in vitro fertilization and culture were divided into 2 groups. Treated oviductal cells were infected with BVDV while control cells were not exposed to the virus. Two approximately equal groups of mature oocytes from each cow were inseminated, and the presumptive zygotes were cultured with infected or noninfected oviductal cells. After 7 d in culture, zona pellucida-intact morulae/blastocysts and degenerated ova were washed, sonicated and assayed for the presence of virus. The rates of cleavage and development were also compared by Chi-square analysis. After washing, virus was not isolated from morulae and blastocysts but was isolated from some groups of degenerated ova. Infections of oviductal cells were inapparent and did not significantly (P>0.05) affect rates of cleavage or development.

Journal Article↗
PubMed1994

Intraindividual stability in the organization and patterning of behavior: incorporating psychological situations into the idiographic analysis of personality.

In nomothetic analyses, the cross-situational consistency of individual differences in social behavior, assessed in vivo in a camp setting, dependent on the similarity in the psychological features of situations. As predicted by the social-cognitive theory of personality, idiographic analyses revealed that individuals were characterized by stable profiles of if ... then ...,situation-behavior relationships that formed "behavioral signatures" of personality (e.g., he aggresses when warned by adults but complies when threatened by peers. Thus, the intraindividual organization of behavior variation across situations was enduring but discriminatively patterned, visible as distinctive profiles of situation-behavior relationships. Implications were examined for an idiographic reconceptualization of personality coherence and its behavioral expressions in relation to the psychological ingredients of situations.

Adolescent↗
PubMed1994

Sensory nerve conduction velocity of the dorsal penile nerves of bulls.

Mean conduction velocity of sensory axons of the dorsal penile nerves of clinically normal bulls was determined by recording action potentials evoked by cutaneous stimulation. Locations of stimulating and recording electrodes were standardized. Overall mean +/- SD conduction velocity was 55.1 +/- 5.1 m/s. Mean +/- SD velocity recorded from the distal electrode was 53.3 +/- 4.9 m/s; velocity recorded from the middle electrode was 55.3 +/- 5.0 m/s; and velocity recorded from the proximal electrode was 56.7 +/- 5.1 m/s. Differences among means were not significant. Four bulls had mean conduction velocities of 54.0 m/s and 48.4 m/s before and 3 weeks after castration, respectively.

Analysis of Variance↗
PubMed1994

Which dogs bite? A case-control study of risk factors.

OBJECTIVE: Dog bites cause an estimated 585,000 injuries resulting in the need for medical attention yearly and children are the most frequent victims. This study sought to determine dog-specific factors independently associated with a dog biting a nonhousehold member. METHODS: A matched case-control design comprising 178 pairs of dogs was used. Cases were selected from dogs reported to Denver Animal Control in 1991 for a first-bite episode of a nonhousehold member in which the victim received medical treatment. Controls were neighborhood-matched dogs with no history of biting a nonhousehold member, selected by modified random-digit dialing based on the first five digits of the case dog owner's phone number. Case and control dog owners were interviewed by telephone. RESULTS: Children aged 12 years and younger were the victims in 51% of cases. Compared with controls, biting dogs were more likely to be German Shepherd (adjusted odds ratio (ORa) = 16.4, 95% confidence interval (CI) 3.8 to 71.4) or Chow Chow (ORa = 4.0, 95% CI 1.2 to 13.7) predominant breeds, male (ORa = 6.2, 95% CI 2.5 to 15.1), unneutered (ORa = 2.6, 95% CI 1.1 to 6.3), residing in a house with > or = 1 children (ORa = 3.5, 95% CI 1.6 to 7.5), and chained while in the yard (ORa = 2.8, 95% CI 1.0 to 8.1). CONCLUSIONS: Pediatricians should advise parents that failure to neuter a dog and selection of male dogs and certain breeds such as German Shepherd and Chow Chow may increase the risk of their dog biting a nonhousehold member, who often may be a child. The potential preventability of this frequent public health problem deserves further attention.

Animals↗