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Biomedical subjects

J C Holmes

Publications and source records attributed to J C Holmes.

63 records · Page 4Linked to original sources
PubMed1969

Hemodynamic effects of isoproterenol and norepinephrine in acute cardiac tamponade.

The hemodynamic effects of isoproterenol infusion, 0.5 mug/kg per min were evaluated in eight intact anesthetized dogs during cardiac tamponade. During tamponade, the mean of pericardial pressures was increased from - 1.5 to 12.5 mm Hg, and the mean of right atrial pressures was increased from 1 to 12.4 mm Hg. Mean cardiac output fell from 144.8 to 44.8 ml/kg per min (P < 0.001), and rose to 105.6 ml/kg per min (P < 0.001) with isoproterenol. Mean cardiac stroke volume fell from 20.3 to 6.1 ml during tamponade (P < 0.001) and rose to 12.1 ml with isoproterenol (P < 0.001). The heart rate increased from 193.3 beats/min during tamponade to 217.5 beats/min with isoproterenol (P < 0.05). During isoproterenol infusion, the mean right atrial pressure and mean pericardial pressure decreased significantly. With cardiac tamponade, the mean blood pressure fell from 157.5 to 126.1 mm Hg (P < 0.01) and did not change significantly with isoproterenol, 11 additional animals were studied with norepinephrine infusion during tamponade. There were no consistent hemodynamic effects with infusions of 0.5 and 1 mug/kg per min. With norepinephrine 2, 5, and 10 mug/kg per min cardiac output rose in some experiments. Isoproterenol infusion increased the cardiac output during tamponade principally by increasing cardiac stroke volume and to a lesser degree by increasing the heart rate. It is postulated that the increased stroke volume resulted from an increased ejection fraction with greater decrease in end-systolic than end-diastolic ventricular volume. These effects are consistent with the known positive inotropic, peripheral vasodilator, and positive chronotropic effects of isoproterenol.

Animals↗
PubMedDate not supplied

Iliotibial band syndrome in cyclists.

Iliotibial band syndrome is an overuse injury caused by repetitive friction of the iliotibial band across the lateral femoral epicondyle. Once considered an injury indigenous to runners, it is now frequently being seen in cyclists. The purpose of this paper is to identify iliotibial band syndrome as a significant problem in cyclists and to propose both operative and nonoperative measures for treating cyclists. Nonoperative measures specific to cyclists consist of bicycle adjustments and training modifications. These are adjunctive therapies to stretching, icing, rest, and oral nonsteroidal antiinflammatory drugs. For cyclists requiring operative intervention, a new surgical technique for excising or releasing the distal iliotibial band is presented. This technique, used by the senior author (JCH) since 1984, involves excision of an elliptical piece of the distal posterior band off the lateral femoral epicondyle.

Bicycling↗
PubMedDate not supplied

[Progress of ecological parasitology--parasite communities].

Many of the major development in the field of parasite community ecology have been due to a switch in focus from a search for pattern to investigation of the processes that produce those patterns. This switch has been accompanied by a recognition that different processes operate at the scale of the individual host (processes determining host specificity and attributes of the niches of the parasites), within the unit of habitat (processes determining population dynamics, exchange of parasites, and transmission), and among units of habitat (processes determining colonization, extinction, or local speciation of parasites). Further developments are likely to depend upon the coordinated use of models, experimental approaches, and field observations aimed at clarifying the conditions under which the processes at each scale became particularly important.

Animals↗