Search PubMed⌕ Search

Biomedical subjects

B Rogers

Publications and source records attributed to B Rogers.

At least 199 records · Page 11Linked to original sources
PubMed1977

A comparative study of the behavioural responses induced by chronic administration of methamphetamine and amphetamine in mice.

The behavioural effects induced in mice by the chronic administration of (+)-methamphetamine (MA) and (+)-amphetamine (A) at three dosages were studied under identical research conditions. The results indicated that MA exerted greater central excitation than A. At the dosage 0.64 mg/kg quiescence was decreased and activity increased more by MA than A. Hyperactivity induced at the 2.5 mg/kg dosage was sustained over a longer time period with MA. Frenzied self-tearing emerged with repeated drug administration at the 10 mg/kg dose in more MA-treated than A-treated animals.

Animals↗
PubMed1976

Measurement of acute and chronic behavioural effects of methamphetamine in the mouse.

A simple and reliable method was developed for rating the dose-related behavioural effects of methamphetamine in male Swiss Albino mice for acute or chronic drug treatment. This procedure was based on a frequency count of certain behaviours made at 15-min intervals over a 90-min period following drug administration. The Fisher Randomization procedure was adapted to analyze behavioural data for the chronic studies. Clear-cut, dose-related behavioural responses occurred following acute (+)-methamphetamine administration and ranged from decreased quiescence (0.64 mg/kg) through increased locomotor activity (2.5 mg/kg), a mixture of stereotyped behaviour and increased locomotor activity (5.0 and 7.5 mg/kg), to primarily stereotyped gnawing, licking or sniffing (10 mg/kg). In studies involving chronic administration of (+)-methamphetamine at 0.64, 2.5 and 10 mg/kg conducted over six and seven weeks, behavioural responses were more exaggerated than in acute studies. All behaviours returned to normal levels in the recovery week except for locomotor activity at the 10 mg/kg dosage. In some animals, chronic treatment with 10 mg/kg (+)-methamphetamine led to protracted self-tearing that replaced the gnawing, licking, sniffing stereotype.

Animals↗
PubMed1973

Nonimmune chemotaxis in vivo: inhibition by complement depletion with cobra factor.

Wistar rats were depleted of complement components using purified cobra venom factor (CoF) administered over a 30-hour period by intraperitoneal injection. Complement depletion was confirmed by immunodiffusion assay, hemolytic assay and inhibition of the reverse Arthus reaction. Rats depleted to below 3% of their normal serum complement level showed marked inhibition of chemotaxis into inflammatory fluid produced in polyvinyl sponges 24 hours after implantation into the dorsal subcutaneous region. Subsequent studies were done to test the effect of high local concentrations of CoF on the microcirculation, the neutrophil and the connective tissue. Local exposure of these tissues and cells to CoF in vivo had no inhibiting effect on chemotaxis. Cobra venom factor did not affect neutrophil survival in vitro or in vivo. The most likely hypothesis is that CoF works by depleting complement and that in vivo chemotaxis of the nonbacterial, nonimmune type is complement dependent to the extent of 60 to 80%. The system described allows for quantitative determination of chemotaxis in vivo.

Animals↗
PubMedDate not supplied

Color flow mapping for myometrial invasion in women with a prior cesarean delivery.

OBJECTIVES: Our aim was to evaluate the utility of color flow mapping in the prediction of placental myometrial invasion in women with Cesarean delivery. METHODS: Ultrasound color flow mapping was performed on placental implantations in potential proximity to the hysterotomy scar. The smallest myometrial thickness was measured under the placenta to evaluate the degree of myometrial attenuation in this area and note was made of unusual vascular lakes. RESULTS: Two hundred fifteen women with placentas in proximity to the prior hysterotomy scar underwent color Doppler mapping. Of 20 women with placenta previa and Cesarean delivery, 15 had Cesarean hysterectomy for bleeding complications and nine had the pathological diagnosis of placental invasion. The measurement of <1 mm for the smallest myometrial thickness or presence of large intraplacental lakes was predictive of myometrial invasion (sensitivity 100%, specificity 72%, PPPV 72%, and NPV 100%). CONCLUSIONS: Color flow mapping predicted myometrial invasion when the smallest myometrial thickness was <1 mm and large intraplacental lakes were demonstrated.

Cesarean Section↗
PubMedDate not supplied

Group intervention with pre-recovery patients.

This article examines treatment outcomes of alcohol and drug abusing patients admitted to a university-based alcohol and drug outpatient clinic. Treatment effectiveness of two treatment models were evaluated. The psycho-educational approach utilized a teacher-student model with the goal of imparting information about drugs and consequences of use. The recovery-oriented approach utilized a patient-counselor collaborative model where patients were encouraged to be active in progressing through sequential stages of pre-recovery tasks. Patients in the psycho-education group stayed in treatment longer and were more likely to rate treatment as useful. Results showed minimal differences between the two groups in terms of Addiction Severity Index scores, Drug Attitude, and urine drug screen results.

Adult↗
PubMedDate not supplied

Monocular aniseikonia: a motion parallax analogue of the disparity-induced effect.

Mayhew and Longuet-Higgins have recently outlined a computational model of binocular depth perception in which the small vertical disparities between the two eyes' views of a three-dimensional scene are used to determine the 'viewing parameters' of fixation distance (d) and the angle of asymmetric convergence of the eyes (g). The d/g hypothesis, as it has been called, correctly predicts that a fronto-parallel surface, viewed with a vertically magnifying lens over one eye, should appear to be rotated in depth about a vertical axis. We report here a comparable illusion for surfaces specified by monocular motion parallax information, which can be explained more simply by considering the differential invariants of the optic flow field. In addition, our observations suggest that the disparity-induced effect is not a 'whole field' phenomenon nor one limited to small magnification differences between the eyes.

Aniseikonia↗
PubMedDate not supplied

Treatment of infertile patients by intrauterine insemination of washed spermatozoa.

Thirty-five couples with a variety of infertility problems were treated by a sperm-washing and intrauterine-insemination method. The husband's semen was washed with a modified Biggers, Whitten, and Whittingham's medium to obtain a seminal plasma-free, highly concentrated sperm suspension for intrauterine insemination. Couples receiving these inseminations were evaluated by semen analysis, zona-free hamster egg penetration test (EPT), post-coital test (PCT), antisperm antibody test (ASAT), and other appropriate infertility tests to determine the possible cause of infertility. The pregnancy rate as a group was 17%, while the spontaneous rate was found to be only 7%. Patients with a poor PCT result had a good success rate (25%) especially if the male's fertilizing ability appeared normal in the EPT (50% success). This treatment did not help men with poor EPT results or reduced sperm concentration (5% and 0% success). By excluding unsuccessful patients attempting less than three months, the calculated conception rate for this treatment is 33%. No infection or other serious complications were reported. It is concluded that this method is an uncomplicated and effective treatment for certain infertility patients. The patients most likely to be assisted by this method can be identified by using the EPT, PCT, and ASAT, and these patients should be treated for a minimum of three cycles.

Animals↗
PubMedDate not supplied

Municipal healthcare workers: work-related health hazards.

Municipal healthcare workers are at risk for a variety of occupational health hazards as a result of daily exposure to work-related biological, chemical, enviromechanical, physical, and psychosocial agents. In addition, this population of workers has not been well studied, so the actual risk may be substantially underreported. This chapter describes these risks and hazards as well as prevention and control strategies. A clear and concerted emphasis on specifically targeting this at-risk workforce both in terms of hazard identification and developing and measuring strategies for risk reduction should be a high priority.

Accidents, Occupational↗
PubMedDate not supplied

Forty year trends in Canadian tobacco sales.

Despite high taxes, the price of tobacco products continues to be a "bargain" for smokers. This paper presents trends since 1950 in real tobacco price index, per capita real disposable income, smoking prevalence, and sales of cigarettes and fine-cut tobaccos. In addition, an "effective tobacco price index", which is the ratio of the real tobacco price index to per capita (age 15+) real disposable income, indexed to a base year (1950) is discussed. This index gives the price of tobacco products as a fraction of real disposable income. The data indicate that, in 1991, the "effective tobacco price" is only 78% of 1950 values.

Canada↗