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Biomedical subjects

C Thompson

Publications and source records attributed to C Thompson.

At least 415 records · Page 23Linked to original sources
PubMed1981

Effect of gonadectomy on the ontogeny of estrogen-binding components in rat liver cytosol.

These studies elucidate the ontogeny of two classes of estrogen-binding sites present in rat liver cytosol. The first class of sites is precipitated from whole cytosol fractions by ammonium sulfate (30% saturation) and exhibits characteristics of specific estrogen receptors. Detectable levels of receptors are attained during the third postnatal week. During days 30--40, receptors reach maximum concentration and remain relatively constant thereafter. The second class of sites, detected in whole cytosol fractions, possess a high binding capacity for estrogens and are present in similar amounts in male and female liver before day 34. However, between days 34--40 male levels increase dramatically while female levels remain constant. This sex difference is maintained throughout the duration of the study (160 days). Specific estrogen receptors from immature (26 days) and mature (70--80 days) rat liver have similar characteristics in terms of sedimentation properties in sucrose gradients, ligand binding specificity, and heat and pronase susceptibility. After prepuberal (19--21 days) gonadectomy, levels of receptor in subsequent adult animals of both sexes are increased approximately 40%. No alterations in receptor levels are seen after neonatal (day 1) castration of males. Prepuberal (day 19) gonadectomy does not alter the normal development of sexual differentiation of high capacity estrogen-binding sites. However, after neonatal (day 1) castration male rats, levels of those sites do not undergo sexual differentiation, and neonatally castrated adult males exhibit female levels of high capacity estrogen-binding site. These studies suggest that sexual differentiation of high capacity estrogen-binding sites may be programmed at birth by testicular androgens.

Aging↗
PubMed1981

Use of hypertension and electroencephalographic monitoring during carotid endarterectomy.

Intraoperative hypertension and continuous electroencephalographic (eeg) monitoring were used during 42 carotid endarterectomies performed on 37 patients from 1970 to 1978. Computer spectral analysis of a majority of the electroencephalograms was also performed. Under supplemented nitrous oxide general anesthesia, elevation of the mean arterial blood pressure to 20% above the individual's preoperative mean blood pressure resulted in reversal to normal of an ischemic EEG pattern in 19% of the patients. The authors discuss the benefit of this technique. they present guidelines for patient selection and analyse the data to help the surgeon decide whether to use shunt during carotid endarterectomy.

Aged↗
PubMed1981

Studies on the quality of specimens obtained by skin puncture of children 1. Tendency to hemolysis, and hemoglobin and tissue fluid as contaminants.

When preferred skin-puncture and blood-collecting techniques were used, the mean artifactually produced hemoglobin in 417 samples of plasma from pediatric patients was 260 mg/L. Highest values occurred exclusively in newborns, 0 to 13 days old (n = 176; mean, 390 mg/L), one-third of whom were premature. The highest value was 1470 mg/L. Only 3% of the samples exceeded 1000 mg/L. After 13 days, technically produced hemolysis is about the same as that for adult plasma (less than 200 mg/L). When skin-puncture and blood-collecting techniques are faulty--e.g., from excessive squeezing at the puncture site--plasma K and hemoglobin may be increased in the newborn to 13-day-old infant, and occasionally in older subjects. By determining plasma hemoglobin, K, blood hemoglobin, and hematocrit the contribution of "tissue fluid" is readily calculated. With excessive squeezing at the sampling site, tissue fluid sometimes contaminates plasma with hemoglobin and K, particularly in the youngest group. Values for alanine and aspartate aminotransferases, lactate dehydrogenase, inorganic P, and Na were little altered, even with squeezing, a fact particularly surprising for the enzymes, which are known to be present in markedly higher concentrations in erythrocytes and other tissues. Our data validate the Elson--Ivor--Gochman method (Am. J. Clin. Pathol. 69: 354-355, 1978) for quantitation of hemoglobin in plasma.

Adult↗
PubMed1981

The role of incompetence of the anterior cruciate and lateral ligaments in anterolateral and anteromedial instability. A biomechanical study of cadaver knees.

UNLABELLED: The anterolateral and anteromedial stability of seventeen fresh frozen cadaver knees was studied in a test apparatus designed to simulate physiological conditions. Statistically significant increases in internal rotation occurred in seven knees when only the anterior cruciate ligament was sectioned, and these increases were enhanced by subsequent sectioning of the posterolateral complex and the lateral collateral ligament, singly or in combination. On the other hand, sectioning of the posterolateral complex and of the lateral collateral ligament, leaving the anterior cruciate intact, did not produce significant increases in internal rotation until the anterior cruciate ligament was sectioned in seven knees. When the entire anterolateral capsule was sectioned as far posterior as the lateral collateral ligament in three knees, no changes in internal or external rotation occurred. Only when the posterolateral complex was sectioned was there a significant increase in external rotation in any of the ligament-sectioning sequences. Thus, it appears that for pathological internal rotation of the tibia on the femur to occur, the anterior cruciate ligament must be incompetent. CLINICAL RELEVANCE: The test apparatus and the results are useful in assessing which ligament structures contribute to clinically noted rotational knee instabilities.

Biomechanical Phenomena↗
PubMed1979

Methods for rapid detection of human ocular viral infections.

Recent methods for detection of viruses in clinical specimens include immunofluorescence, immunoperoxidase, immune adherence hemagglutination, radioimmunoassay, enzyme-linked immunosorbent assay (ELISA), and immunoelectron microscopy. Some are useful for the detection of traces of viral antigens but are more complicated and time-consuming than others. Simple techniques of immunofluorescence and negative stain electron microscopy are used for the rapid detection of viruses in human adenoviral, herpetic, rubella, molluscum contagiosum, and vaccinial infections.

Adenoviridae Infections↗
PubMed1979

The effect of phenylephrine on excretion of fluid and electrolytes by the parotid and mandibular glands of the rat.

The effect has been investigated of the alpha-adrenergic agonist, phenylephrine, on excretion of water and electrolytes (Na, K, and HCO3) by the parotid and mandibular glands of the rat. In the mandibular glands the agonist was as effective as acetylcholine (or parasympathetic nerve stimulation) in stimulating secretion, and the electrolyte excretory patterns seen in the two modes of stimulation were similar. In the parotid gland, phenylephrine was only one-fifth as potent as acetylcholine (or parasympathetic nerve stimulation) in evoking a secretory response but, when due allowance for flow rate differences is made, the electrolyte excretion patterns were similar. In both glands the secretory response to phenylephrine was totally different, in magnitude and in electrolyte excretion pattern, to that evoked by the beta-adrenergic agonist, isoprenaline. It is concluded, as has already been established for secretion of exportable protein, that alpha-adrenergic agonists have very similar effects to muscarinic agonists both on endpiece and on duct cells and that these actions are completely different from those evoked by activation of beta-adrenergic receptors.

Animals↗
PubMed1979

Development of high resolution computed tomography of the spinal cord.

Computed tomography of the spinal cord was a natural development of total body scanning. Much time and effort was spent in order to visualize the spinal cord and the various conditions affecting it. This was achieved by using an EMI CT5005 scanner and a series of step by step modifications and improvements to obtain a very high degree of resolution. The large variety of intraspinal lesions seen at the Montreal Neurological Hospital allowed us, by selecting appropriate cases, to determine the value of CT of the spinal cord.

Humans↗
PubMed1977

Studies of the surgical scrub.

A study comparing the relative efficacy of a five versus a ten minute surgical scrub was carried out using random sampling of personnel scrubbing for routine scheduled hospital surgical procedures. Scrubbing for five minutes was found to be equally as effective as scrubbing for ten minutes. Betadine was compared to pHisoHex as a scrubbing agent and found to be statistically more effective in degerming the skin following a five minute scrub. As a result of this study, a routine preoperative surgical scrub of five minutes' duration, using Betadine as the scrubbing agent, is recommended.

Hand↗