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Biomedical subjects

M Pearce

Publications and source records attributed to M Pearce.

53 records · Page 3Linked to original sources
PubMed1980

A comparison of the in vivo uptake of [3H]GABA into rat celebral cortex and dorsal medulla following topical application.

The penetration of [3H]GABA and [14C]sucrose from the dorsal surface of the rat medulla and cerebral cortex was studied in vivo. The levels of both declined exponentially from the surface of both regions and were decreased by raised potassium levels and the presence of GABA uptake inhibitors. Inhibition of GABA metabolism increased the amounts of 3H recovered particularly after long incubation periods. More [3H]GABA and [14C]sucrose was tken up into the cerebral cortex than the medulla, and more [3H]GABA than [14C]sucrose was taken up in both regions.

Animals↗
PubMed1980

Recovery of cardiac function with total transapical left ventricular bypass.

Transapical left ventricular bypass which withdraws blood directly from the left ventricular apex through a roller pump and outflow filter with return to the femoral artery has been applied in 6 patients with cardiac failure. All patients required total TALVB (with the aortic valve closed) for periods of one to 144 hrs, and 2 patients had recovery of life-sustaining myocardial function, allowing removal of the TALVB system. One patient had complete recovery without other organ dysfunction. Total TALVB continuously decompresses and unloads the left ventricle throughout systole and diastole, and maintains the circulation in otherwise terminal circumstances.

Adult↗
PubMedDate not supplied

Use of the pinna reflex as a test of hearing in mutant mice.

Although it is a gross measure, the pinna reflex test is easily administered and is, therefore, incorporated as a general screening tool in mutagenesis programs. Our recent application of this approach indicated that mutant mice lacking one of the small Maf proteins, in this case MafG, failed to exhibit a pinna reflex. In contrast, littermate controls, with the same mixed 129/CD1 background, and including both wild type and heterozygous mutant animals, passed the test. Because previous studies indicate that mafG is expressed in both cochlear and vestibular parts of the mouse inner ear, the source of this 'presumed deafness' was further assessed by making round window recordings to determine compound action potential thresholds. Auditory brainstem responses were also acquired to assess function along portions of the central auditory pathway. In all cases, responses in homozygous mutants (-/-) were comparable to those obtained from littermate controls, either wild type (+/+) or heterozygous mutants (+/-). Gross anatomy of the organ of Corti was also found to be similar in all three groups of mice. Hence, the lack of a pinna reflex must relate to nonauditory causes.

Acoustic Stimulation↗
PubMedDate not supplied

Drug testing in Canadian jails: to what end?

Since 1995, Corrections Services Canada (CSC) has conducted randomized urinalysis screening of a minimum of 5% of the federal inmate population on a monthly basis. Urine samples are screened for a broad range of psychoactive substances. The stated purpose of such screening is to reduce substance use in federal jails. Analysis of data provided by CSC for testing between 1994 and 1998 reveals small but statistically significant increases in the percentage of all urine samples that tested positive over that time. Analysis of the results of screening for opiates, cocaine and THC from data provided by CSC for the same time period, shows steady rates of opiate and cocaine detection at maximum and medium levels of security, decreases in opiate and cocaine detection in minimum security, and statistically significant increases in THC detection at all levels of security. The implications of these findings are discussed.

Canada↗