Biomedical subjects

M R Anderson

Publications and source records attributed to M R Anderson.

13 recordsLinked to original sources

PubMed1992

Detection of internal carotid artery stenosis: comparison of MR angiography, color Doppler sonography, and arteriography.

Findings of two-dimensional time-of-flight magnetic resonance (MR) angiography projection angiograms were prospectively compared with those of color Doppler sonography by using angiography as a standard in 23 consecutive patients (42 carotid bifurcations) to evaluate their utility in determining the presence of carotid artery stenosis. MR angiography helped detect 50% or greater lumen diameter stenosis (sensitivity, 0.96; specificity, 0.64). Color Doppler sonography with 1.25 m/sec peak systolic velocity as a threshold had a sensitivity of 0.96 and a specificity of 0.71. Statistical analysis showed a correlation between percentage of lumen diameter narrowing and the length of the zone of signal intensity loss with MR angiography (r = .69; P less than .0001). A stronger relationship was obtained between angiographic narrowing and peak systolic velocity derived from color Doppler sonography (r = .80; P less than .0001). Two-dimensional time-of-flight MR angiography displayed as projection angiograms and combined with carotid artery and combined with carotid artery sonography is a useful approach for helping detect and potentially grade the severity of stenoses of the carotid artery.

Aged↗

PubMed1992

The requirement of fibroblasts to confirm the identity of cytogenetic centric fusion (CF) carriers in same-sex twin cattle.

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Animals↗

PubMed1989

Characteristics of medical schools and their affiliated institutions.

Survey data from a sample of 58 U.S. and six Canadian medical schools were used to describe the current network of medical schools and their affiliates. Results showed that each medical school in the study averaged over 11 affiliates. The largest percentages of affiliates reported were in the categories of "community" hospitals (that is, the nongovernmental, not-for-profit hospitals), Veterans Administration hospitals, and city hospitals. Characteristics of the medical schools, such as class size, ownership, year established, and the presence of a university hospital, were not related to either the number or the kind of affiliates. However, the sizes of the affiliated institutions were associated with the year the medical school was established, the presence of a university hospital, and the class size of the medical school.

Canada↗

PubMed1986

Preclinical curriculum characteristics and institutional performance on NBME. Part I.

A study was conducted that analyzed the relationship between various characteristics of the preclinical curriculum and institutional performance on the Part I examination of the National Board of Medical Examiners (NBME) at a sample of 85 U.S. medical schools. Total scheduled hours per week was the single curriculum characteristic having a positive and significant relationship with institutional NBME examination performance. However, when the data were controlled by medical school selectivity in admissions and institutional policy on the taking of the examination, total scheduled hours per week failed to make a significant contribution to the prediction of performance. The results were viewed as failing to provide support and justification for intense preclinical curriculum loads on the basis that this would enhance NBME examination performance. The authors conclude that simple comparisons of schools on the basis of mean NBME examination performance are meaningless unless the entering abilities of students and school policies on the examination are taken into account. The authors also suggest that those schools that prescribe heavy and intense preclinical curriculum loads should reexamine those policies in light of recommendations of the Project Panel on the General Professional Education of the Physician and College Preparation for Medicine.

Certification↗

PubMed1984

Left ventricular adaptation to volume overload from large aortocaval fistula.

The manner in which the left ventricle responds to an acute volume overload has not been well defined. Left ventricular performance was studied in six chronically instrumented resting awake dogs in the control state and serially after creation of a large abdominal aortocaval shunt. Ultrasonic transducers measured minor and major axis diameters and equatorial wall thickness. Left ventricular pressure was obtained with micromanometers. Cardiac contractility was evaluated by the load-independent contractility index, EMAXsc (slope of the normalized end-systolic equatorial midwall circumferential stress-equatorial midwall circumference relationship). By 1 week postshunt, the dog had clinical signs of congestive heart failure (ascites, dyspnea, limb edema); although systolic aortic pressure remained stable, heart rate, end-diastolic volume, pulse pressure (systolic minus diastolic pressure), cardiac output, minute work and dp/dtmax were significantly increased. At 1 week the calculated left ventricular mass was increased by 10.1% +/- 4.0% above control. EMAXsc was significantly increased immediately after shunting but returned to control at 1 day and was less than control at 1 week. Thus adaptation of the left ventricle to acute volume overload is characterized by use of inotropic, chronotropic, and Starling reserves. However, chronic volume overload is characterized by decreased inotropic state and an apparent increase in hemodynamic performance (dp/dtmax, cardiac output, minute work), which appears to be maintained by an increase in cardiac mass and by chronotropic and Starling reserves.

Adaptation, Physiological↗

PubMed1981

Pyloric stenosis--a report of triplet females and notes on its inheritance.

Pyloric stenosis has been reported in multiple sibs and multiple births, A case of the disease affecting triplets is reported, the second in the literature. The expression of pyloric stenosis is dependent upon the genetic influence of ancestors affected with the disease, as well as unknown environmental influences in the postnatal period. Descendants of affected females are the most likely to develop pyloric stenosis.

Female↗

PubMed1977