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Biomedical subjects

J C Kerr

Publications and source records attributed to J C Kerr.

At least 19 recordsLinked to original sources
PubMed2000

Health promotion and senior women with limited incomes.

Health promotion is increasingly being recognized as making an important contribution to the well-being of Canada's seniors. Most research relating to this topic, however, has focused on middle-income senior men and women. An exploratory study using ethnographic methods was conducted to explore and describe the health promotion experience of senior women living on limited incomes. Interviews with a total of 11 urban senior women living on limited incomes were analyzed. A major finding of this study was that the women utilized a wide variety of "ways of living" that are presented in the model, Health Promotion as Self Nurturance. Health promotion was perceived to be influenced by living on a limited income by most participants; however, 3 of the participants believed that their health status and income level were unrelated. Findings are discussed and implications for community health nurses are offered.

Aged↗
PubMed1995

Visions realized and dreams dashed: Helen Penhale and the first basic integrated baccalaureate program in nursing in the west, at the University of Alberta 1952-1956.

The first basic degree program in nursing in Canada was established at the University of British Columbia in 1919. This program and those that followed elsewhere were of the non-integrated form, wherein a diploma program offered by a hospital was supplemented by university courses in the arts, humanities, and sciences. In 1942 an innovative basic baccalaureate program in nursing was established at the University of Toronto; courses in nursing, given by the university, were offered in conjunction with university courses in other subjects. Only two other attempts were made to set up integrated programs in Canada prior to release of the Report of the Royal Commission on Health Services of 1964; McMaster University established a program in 1946, and, in an attempt that was ultimately unsuccessful, a program was established at the University of Alberta in 1952. The purpose of this study was to examine the conditions surrounding the initiation and termination of a basic degree program in the 1950s at the University of Alberta, in order to understand the key issues in the movement to establish basic university degree programs for nurses, and the gender discrimination relative to nurses and nursing students that has prevailed in health and education. Although the conflict at the University of Alberta was a very difficult one for the nurses involved, and although the Director who had the temerity to establish the program relinquished her position when the program was summarily terminated, this episode in Canadian nursing history provides insight into the climate in which baccalaureate nursing education existed and into some of the issues relative to its development.

Alberta↗
PubMed1988

Heparin decreases ischemia-reperfusion injury in isolated canine gracilis model.

The mechanisms of ischemia-reperfusion injury in skeletal muscle remain controversial. Some investigators have demonstrated that heparin can ameliorate ischemic injury to heart, brain, and renal tissue. We investigated the ability of heparin sodium to decrease ischemia-reperfusion injury in an isolated gracilis muscle model in ten anesthetized mongrel dogs. One gracilis muscle was perfused normally while the contralateral muscle was subjected to six hours of ischemia followed by one hour of reperfusion. Five dogs were given a preischemic bolus of heparin sodium (200 U/kg, intravenously followed by a continuous infusion (15 U/kg/h, intravenously), and five control dogs received no heparin. Quantitation of skeletal muscle ischemia-reperfusion injury was determined by histochemical staining with triphenyl tetrazolium-chloride and computerized planimetry of the infarct size. Results from the ischemic muscle demonstrate a significant beneficial effect of heparinization. The nonheparinized dogs had a 72% +/- 5% infarct size, which was significantly reduced to 24% +/- 8% in the heparinized dogs. The mechanism of this protective effect may be due to heparin's anticoagulant, antiplatelet, or anti-inflammatory action.

Acute Disease↗
PubMed1988

Doppler ultrasound, laser Doppler, and perfusion fluorometry in bowel ischemia.

Improved accuracy and objectivity in the evaluation of intestinal viability has been reported by some investigators using Doppler ultrasound, and more recently laser Doppler velocimetry and perfusion fluorometry. To compare the sensitivity and clinical applicability of these techniques, intestinal viability was evaluated by each method in nine 15- to 50-cm loops of small bowel prepared by division of the mesenteric vasculature in five anesthetized dogs. The sensitivity of Doppler ultrasound was 86%, of laser Doppler flow velocity 85%, of laser Doppler index 94%, and of perfusion fluorometry 95%. Though the sensitivity of Doppler ultrasound is significantly less than that of laser Doppler and perfusion fluorometry, this is not unexpected since the latter two techniques are more quantitative than Doppler ultrasound. Clinically, Doppler ultrasound compares favorably with laser Doppler and perfusion fluorometry, and its low cost and simplicity suggest its adjunctive use in the operative setting.

Animals↗
PubMed1988

Rate of reperfusion blood flow modulates reperfusion injury in skeletal muscle.

The mechanisms of ischemia-reperfusion (I-R) injury in skeletal muscle remain controversial. We investigated the effect of the rate of reperfusion blood flow on I-R injury in an isolated in vivo canine gracilis muscle model in six anesthetized dogs. In all animals, both gracilis muscles were subjected to 6 hr of ischemia followed by 1 hr of reperfusion. During reperfusion, one gracilis artery was partially occluded to limit the rate of reperfusion blood flow to its preischemic rate (limited reperfusion, LR), while the contralateral artery was allowed to perfuse freely at a normal rate (normal reperfusion, NR). Muscle injury was quantified by histochemical staining (triphenyltetrazolium chloride, TTC) with computerized planimetry of the infarct size, and by spectrophotometric determination of technetium-99m pyrophosphate uptake. Endothelial permeability was quantified by measurement of gracilis muscle weight gain and 125I-albumin radioactivity after intravenous injection. Results are presented as the means +/- SEM, and differences are considered to be statistically significant if P less than 0.05 by Student's t test for paired data. LR resulted in significantly less blood flow (9.7 +/- 1.7 cc/min/100 g) when compared to NR (55.7 +/- 11.6 cc/min/100 g). I-R injury was significantly reduced by LR as evidenced by a decrease in TTC infarct size from 41 +/- 7% to 11 +/- 5%, and a decrease in technetium-99m pyrophosphate uptake from 512 +/- 20 to 163 +/- 44 X 10(3) counts/min/g. LR also significantly decreased the postreperfusion edema formation as evidenced by a reduction in the muscle weight gain from 27 +/- 6 to 9 +/- 1 g, and a reduction in the 125I-albumin radioactivity from 45 +/- 14 to 32 +/- 8 counts/min/g. These data suggest that the hyperemic rate of reperfusion blood flow is a significant factor in the pathophysiology of postreperfusion edema and that clinical control of reperfusion injury in skeletal muscle may be achieved by limiting the rate of reperfusion blood flow.

Animals↗
PubMed1988

Technetium 99m pyrophosphate quantitation of skeletal muscle ischemia and reperfusion injury.

The study of ischemia and reperfusion injury in the extremity has been hampered by lack of an accurate method of measuring skeletal muscle injury. We used a bilateral isolated in vivo canine gracilis muscle model in 15 anesthetized dogs. The experimental muscles had 4, 6, or 8 hours of ischemia and 1 hour of reperfusion. The contralateral gracilis muscle served as a control. Technetium 99m pyrophosphate (99mTc-PYP), an agent which localizes in injured muscle cells, was used to quantitate canine skeletal muscle damage. After 6 hours of ischemia and 1 hour of reperfusion, there was a significant increase of 215% of 99mTc-PYP uptake in the experimental vs the control muscle. Experimental muscle uptake was 8% greater than control after 4 hours and 405% more after 8 hours of ischemia and reperfusion. Segmental distribution of 99mTc-PYP uptake showed localization to be greatest in the middle of the muscle at the entry site of the gracilis artery. Electron microscopic evaluation also documented this area to have undergone the most severe injury. Distal portions of the muscle did not show increased damage. Our results show that 99mTc-PYP effectively quantitates skeletal muscle ischemia and reperfusion injury. The pattern of 99mTc-PYP uptake suggests that considerable injury is caused during reperfusion.

Animals↗
PubMed1988

Regional hypothermia protects against ischemia-reperfusion injury in isolated canine gracilis muscle.

Regional hypothermia is known to protect many tissues from ischemic injury. We investigated the relationship between regional hypothermia and skeletal muscle ischemia-reperfusion injury in a bilateral in vivo isolated canine gracilis muscle model. In five anesthetized dogs, one gracilis muscle was subjected to 6 hours of ischemia followed by 1 hour of reperfusion while the contralateral muscle served as a nonischemic control. Localization and quantitation of skeletal muscle injury was determined by histochemical staining with triphenyl tetrazolium chloride (TTC) followed by computerized planimetry of the infarct size. Muscle pH and temperature were monitored continuously in the proximal, middle, and distal segments by using pH electrodes and needle thermistors. Muscle pH was calculated by use of the Nernst equation with temperature correction, and hydrogen ion washout rates (H+) were derived from the observed change in muscle pH during reperfusion. A significant (p less than 0.05) regional hypothermia was observed in the distal third of the muscle. The preischemic temperature in the distal muscle was 27 +/- 2 degrees (SEM) C, compared to 34 +/- 1 degree and 32 +/- 2 degrees C in the proximal and middle segments of muscle, respectively. This temperature gradient was sustained throughout the experiment. The distal third of the ischemic muscle demonstrated significantly less (p less than 0.05) injury than the proximal and middle thirds as measured by TTC infarct size (31 +/- 10%, compared to 71 +/- 3% and 78 +/- 6%, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Effectiveness of a program of information and support for myocardial infarction patients recovering at home.

The impact of patient education follow-up by telephone on the knowledge of the postmyocardial infarction (MI) patient was investigated in this study. On the basis of Orem's self-care framework, subjects' levels of knowledge in six criterion areas were assessed according to measurement criteria developed by Horn and Swain. Fifty-one subjects from the total population of MI patients admitted to the coronary care unit of the study hospital during the period of research who met study criteria were randomly assigned to experimental and control groups. Statistically significant differences (p less than 0.05) were found in the knowledge level of the experimental group in the areas of the disease, its effects, related self-care measures, recommended exercises, and all teaching areas together. Although significant differences were not found in the teaching areas of therapeutic diet, medications, physical activity restrictions, and recommended rest, a higher mean was produced for the experimental group in all but one area. These findings demonstrate that a telephone teaching program for MI patients 6 to 8 weeks after hospital discharge can be effective in increasing knowledge relative to the disease, self-care, and therapeutic regimen.

Aftercare↗
PubMed1988

Heparinization reduces endothelial permeability and hydrogen ion accumulation in a canine skeletal muscle ischemia-reperfusion model.

Skeletal muscle injury after revascularization (ischemia-reperfusion) continues to be a major clinical problem. Although heparinization has been recommended, its action in an experimental model of I-R has not been evaluated. We investigated the ability of heparinization to decrease I-R injury in 10 anesthetized dogs (nonheparinized, n = 5; heparinized, n = 5), subjecting one gracilis muscle to 6 hours of ischemia followed by 1 hour of reperfusion while the identically prepared contralateral muscle served as a nonischemic control. Skeletal muscle infarction was determined by Tc-PYP uptake. Endothelial permeability was quantified by measurement of skeletal muscle 125I-Alb activity after intravenous injection. Interstitial hydrogen ion (H+) accumulation was determined by a miniature pH electrode inserted into the gracilis muscle. Isotopic activities from the ischemic muscle were calculated as a percentage of the contralateral nonischemic muscle (mean +/- SEM). Nonheparinized ischemic muscles had an increase in the activities of Tc-PYP and 125I-Alb of 684% +/- 149% and 742% +/- 130%, which were reduced to 218% +/- 54% and 378% +/- 85% by heparinization, respectively (p less than 0.05). During ischemia, the nonheparinized muscles accumulated 1223 +/- 121 nmol of H+ compared with 785 +/- 95 nmol in the heparinized animals (p less than 0.01). This significant reduction in I-R injury may be causally related to diminished endothelial permeability and H+ accumulation.

Animals↗
PubMed1987

Quantitative histochemical evaluation of skeletal muscle ischemia and reperfusion injury.

Acute arterial obstruction to the extremities is associated with significant morbidity and mortality. The evaluation of accompanying skeletal muscle injury has thus far been indirect and imprecise. Triphenyltetrazolium chloride (TTC) is an oxidation-reduction indicator which allows for the histochemical quantitation of skeletal muscle injury. In 21 anesthetized nonheparinized adult mongrel dogs, the isolated in vivo gracilis muscle underwent 4, 6, or 8 hr of ischemia with and without reperfusion. The muscles were excised and cut into 1-cm segments, representative muscle biopsies for electron microscopy were taken, each segment was stained in 1% TTC, and the total area of staining was measured with computerized planimetry. All control muscles stained completely with a dark red color. After 4, 6, or 8 hr of ischemia, quantitative measurements of muscle staining indicative of normal tissue were present in 98 +/- 1%, 59 +/- 5%, and 23 +/- 9% of the total muscle areas, respectively. Six hours of ischemia followed by reperfusion was associated with only 36 +/- 9% of the muscle being stained. Segmental TTC staining demonstrated that reperfusion was associated with greater injury, and less TTC staining, in the proximal portion of the gracilis muscle at the site of entry of the major arterial pedicle. The distal muscle did not demonstrate increased damage with reperfusion. It is hypothesized that protection of the distal muscle from reperfusion injury may be due to an absence of reflow farther away from the artery.

Animals↗
PubMed1986

Effects of prostacyclin injections and infusions on canine femoral hemodynamics.

The use of prostacyclin (PGI2) infusions has been recommended in the management of patients with severe distal arteriopathy, who are not candidates for conventional bypass procedures. Further clarification regarding the route of administration and the optimal dose of this potent vasodilator, however, is needed before controlled clinical trials are initiated. We measured bilateral femoral arterial blood flow electromagnetically in seven anesthetized adult mongrel dogs. Systemic arterial pressure and cardiac output were also measured. Central venous and femoral arterial injections of PGI2 were administered in five doses ranging from 10(-4) to 10(0) micrograms X kg-1 to study the dose response. PGI2 was also infused intravenously and intra-arterially for 20 minutes at a dose of 10(-1) micrograms X kg-1 X min-1. Femoral arterial injections of PGI2 in doses from 10(-4) through 10(0) micrograms X kg-1 caused significant (p less than 0.05) and dose-dependent increases in ipsilateral femoral arterial blood flow. Intravenous injections of PGI2 caused no significant changes in the dose range from 10(-4) to 10(-2) micrograms X kg-1 but resulted in a significant (p less than 0.05) reduction in femoral arterial flow and systemic arterial pressure at doses of 10(-1) and 10(0) micrograms X kg-1. The femoral arterial infusion of PGI2 produced a significant and sustained increase in femoral arterial flow that was not observed during the intravenous infusion. Arterial pressure was unchanged with intra-arterial PGI2 but was significantly reduced during the intravenous infusion. The beneficial hemodynamic effects of intra-arterial PGI2 suggest that further clinical trials should employ this route of administration.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Hemodynamics of an anastomotic arteriovenous fistula.

Various vascular surgical techniques have been employed to increase both graft patency and limb survival when the prognosis for limb salvage in arteriosclerotic patients is especially poor due to a diseased outflow tract. Ibrahim et al described the creation of an anastomotic arteriovenous fistula in distal tibial bypasses as the reconstructive procedure of choice in severely ischemic extremities unsalvageable by more conventional methods. This study presents the hemodynamics of an anastomotic arteriovenous fistula under such circumstances. Four adult mongrel dogs were anesthesized, and a femoral artery and vein were exposed from the groin to the knee. The femoral artery was ligated in midthigh, and the ligated segment was than bypassed using an umbilical vein graft. The distal anastomosis included an arteriovenous fistula. Flow was measured electromagnetically, and pressure was measured with intravascular catheters attached to strain gauges. The creation of an anastomotic arteriovenous fistula rapidly leads to a reversal of flow in the distal artery, distal arterial hypotension, and distal venous hypertension. Its clinical use in contraindicated as a result of our experimental observations.

Animals↗
PubMed1985

Appendicitis versus pelvic inflammatory disease. A diagnostic dilemma.

In order to determine whether any clinical or laboratory findings were helpful in differentiating acute appendicitis (AP) from acute pelvic inflammatory disease (PID), this retrospective study was undertaken. Records of all female patients 12 to 50 years of age, undergoing laparotomy with a preoperative diagnosis of AP over the past 15 years, were reviewed and pertinent data recorded. In comparing AP (n = 106) with PID (n = 39), longer duration of symptoms, relationship of onset of pain to the menstrual cycle, and frequent requests for gynecological consultation distinguished the PID from the AP cases. Although complete reliance cannot be placed on any clinical or laboratory finding in differentiating AP from PID, the final satisfactory outcome justifies laparotomy when the diagnosis cannot be established by other means.

Abdomen↗
PubMed1985

Effects of vasopressin on cardiac output and its distribution in the subhuman primate.

The effects of vasopressin, when administered as intravenous bolus injections and infusions, on cardiac output and the distribution of blood flow to the splanchnic vascular beds were studied in six anesthetized rhesus monkeys. Vasopressin as bolus injections caused dose-dependent decreases in superior mesenteric arterial blood flow. However, small reductions in cardiac output were observed only at the highest doses concomitant with increases in systemic arterial pressure. When vasopressin was infused at the highest dose (5 X 10(-2) units kg-1 min-1) for 10 minutes, cardiac output was unaffected; but sustained reductions in superior mesenteric arterial blood flow and increases in arterial pressure and total peripheral resistance were observed. Infusions of vasopressin (5 X 10(-3) units kg-1 min-1) caused significant and sustained reductions in superior mesenteric arterial blood flow and increases in arterial pressure but no measurable effects on cardiac output or total peripheral resistance. However, there was a significant redistribution of blood flow away from the stomach, small and large intestines, spleen, and pancreas toward the liver (hepatic artery), with no statistically significant change in renal blood flow. On the assumption that comparable responses exist among primates, these data support the clinical use of vasopressin to control gastrointestinal hemorrhage and to offer a probably ideal dose and route of administration.

Animals↗
PubMed1984

Influence of prostacyclin on distribution of canine femoral blood flow.

Prostacyclin (PGI2) has been used clinically in the treatment of ischemic peripheral vascular disease. While intravenous infusions have been reported to be beneficial, the preferred route of administration (intravenous or intraarterial) and the influence of PGI2 on distribution of femoral blood flow have yet to be established. Bilateral femoral arterial blood flow was measured electromagnetically in 10 anesthetized adult mongrel dogs. The distribution of femoral arterial blood flow (FAQ) to skin, muscle, bone, and arteriovenous anastomoses (AVA) was determined by using femoral intraarterial injections of radioactively labeled microspheres before, during, and 30 min after 20-min intravenous (n = 5) and intraarterial (n = 5) infusions of PGI2 at 0.1 microgram kg-1 min-1. Control FAQ was 76 +/- 15 (mean +/- SEM) ml/min and its distribution to skin, muscle, bone, and AVA was 13 +/- 3%, 43 +/- 8%, 17 +/- 4%, and 26 +/- 7%, respectively. Arterial pressure was 127 +/- 7 mm Hg. Intraarterial infusions of PGI2 significantly (P less than 0.05) increased FAQ to 240 +/- 43 ml/min which was sustained throughout the infusion. Distribution of FAQ to skin increased significantly (P less than 0.05) to 47 +/- 8%, while that to the muscle of the thigh decreased to 17 +/- 4% (P less than 0.05). During intravenous infusion of PGI2 at the same concentration, FAQ did not change significantly and its distribution remained unchanged; however, there was a significant (P less than 0.05) reduction in arterial pressure to 78 +/- 6 mm Hg. No significant changes occurred in cardiac output, pulmonary arterial pressure, arterial blood gases, paw or core body temperatures.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Effects of intravenous and intra-arterial infusions of prostaglandin E1 on canine hindlimb blood flow distribution.

Prostaglandin E1 (PGE1) has been used clinically in the treatment of ischemic peripheral vascular disease. However, the preferred route of administration and its influence on the distribution of blood flow to the skin, muscle, bone, and arteriovenous anastomoses ( AVAs ) have yet to be established. Bilateral femoral arterial blood flow was measured electromagnetically in 10 anesthetized adult mongrel dogs (mean weight 16.5 kg). The distribution of femoral arterial flow to the skin, muscle, bone, and AVAs was determined with use of femoral intra-arterial injections of radioactively tagged microspheres (15 +/- 1 mu) before, during, and 1 hour after 20 minutes of intravenous and intra-arterial infusions of PGE1 at 0.1 microgram kg-1 min-1. Intra-arterial infusions caused a significant (P less than 0.003) increase in femoral arterial flow (462 +/- 58 ml X min-1), which was sustained throughout the infusion. The distribution of flow to the skin increased significantly (P less than 0.01) to 24.1 +/- 2.1%, whereas that through AVAs was significantly (P less than 0.05) decreased to 3.2 +/- 0.9%. Femoral arterial blood flow did not change during intravenous infusions; however, there was a significant (P less than 0.01) reduction in the distribution to muscle (41.1 +/- 10.5%) associated with a significant (P less than 0.02) increase in distribution through AVAs (30.8 +/- 11.5%). These data demonstrate the superiority of intra-arterial infusion over intravenous infusions of PGE1 in the canine hindlimb. There was a significant increase in femoral arterial blood flow with increased distribution to the skin and decreased shunting. Femoral arterial blood flow did not change during intravenous infusions; however, a reduction in the distribution of flow to the muscle was accompanied by an increase in shunting.

Alprostadil↗
PubMed1983

Treatment of frostbite with intra-arterial prostaglandin E1.

Prostaglandin E1 (PGE1) is a vasodilator that inhibits platelet aggregation. Its use has been effective intra-arterially in treating ischemic peripheral vascular disease. Its potentially beneficial effect in treating frostbite injuries has not been studied and prompted this investigation. A standard frostbite injury was induced by immersing the hindlimbs of New Zealand white rabbits in an ethylene glycol bath maintained at -15 C. Forty animals were separated into eight equal groups (N = 5). Groups I through V were allowed to slowly rewarm at room temperature (21-22 C), while Groups VI through VIII underwent rapid rewarming in a water bath at 42 +/- 1 C. Groups I and VI received no further treatment. Groups II and VII received intra-arterial bolus injections of saline. Group III received intra-arterial bolus injections of reserpine (2.5 X 10(-3) mg/kg-1). Group IV received intra-arterial bolus injections of PGE1 (10(-1) micrograms/kg-1). Groups V and VIII received 3-hour intra-arterial infusions of PGE1 (10(-1) micrograms/kg-1 min-1). Tissue loss was graded numerically after 30 days. Group V (slow rewarming plus 3-hour PGE1 infusion) had significantly (P less than 0.5) less tissue loss than Group I (slow rewarming alone) and Group II (slow rewarming plus saline). Group V was not significantly different from Groups VI through VIII (rapid rewarming). Group III (slow rewarming plus bolus reserpine) and Group IV (slow rewarming plus bolus PGE1) were not significantly different from Group I (slow rewarming alone). The data suggest a clinical application for the use of PGE1 in frostbite patients who have not undergone rapid rewarming.

Animals↗