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Biomedical subjects

J M Atkins

Publications and source records attributed to J M Atkins.

At least 19 recordsLinked to original sources
PubMed2000

Role of insulin receptor substrate-2 in interleukin-9-dependent proliferation.

Interleukin-9 (IL-9) stimulation results in JAK, STAT and IRS1/2 phosphorylation. The role of IRS adaptor proteins in IL-9 signaling is not clear. We show that IL-9 induces IRS2 phosphorylation and association with phosphatidylinositol-3 kinase (PI 3-K) p85 subunit in TS1 cells and BaF/9R cells, which proliferate upon IL-9 stimulation. We observed a PI 3-K-dependent phosphorylation of protein kinase B (PKB) in TS1 cells, but not in BaF/9R, nor in other IL-9-dependent cell lines. Finally, 32D cells that were transfected with the IL-9 receptor but lack IRS expression survived in the presence of IL-9. Ectopic IRS1 expression allowed for IL-9-induced proliferation, in the absence of significant PKB phosphorylation.

Animals↗
PubMed1997

The physician's role in minimizing prehospital delay in patients at high risk for acute myocardial infarction: recommendations from the National Heart Attack Alert Program. Working Group on Educational Strategies To Prevent Prehospital Delay in Patients at High Risk for Acute Myocardial Infarction.

Physicians and other health care professionals play an important role in reducing the delay to treatment in patients who have an evolving acute myocardial infarction. A multidisciplinary working group has been convened by the National Heart Attack Alert Program (which is coordinated by the National Heart, Lung, and Blood Institute of the National Institutes of Health) to address this concern. The working group's recommendations target specific groups of patients: those who are known to have coronary heart disease, atherosclerotic disease of the aorta or peripheral arteries, or cerebrovascular disease. The risk for acute myocardial infarction or death in such patients is five to seven times greater than that in the general population. The working group recommends that these high-risk patients be clearly informed about symptoms that they might have during a coronary occlusion, steps that they should take, the importance of contacting emergency medical services, the need to report to an appropriate facility quickly, treatment options that are available if they present early, and rewards of early treatment in terms of improved quality of life. These instructions should be reviewed frequently and reinforced with appropriate written material, and patients should be encouraged to have a plan and to rehearse it periodically. Because of the important role of the bystander in increasing or decreasing delay to treatment, family members and significant others should be included in all instruction. Finally, physicians' offices and clinics should devise systems to quickly assess patients who telephone or present with symptoms of a possible acute myocardial infarction.

Algorithms↗
PubMed1997

Developing shared learning in multiprofessional health care education: for whose benefit?

A selection of examples from programmes of shared learning indicates that the movement towards collaboration among health care professionals is thought of as a good thing and ways and means of achieving it need to be fostered. But just who are the supposed beneficiaries of such collaboration and should more work be done in analysing the assumptions that underpin much of this work? A literature review indicates a number of threats as well as opportunities for health care professionals emanating from this work, each of which needs careful consideration by educationalists. A brief analysis of the intentions of the teachers on a BA(Hons) Health Care Studies programme indicates that their approach may be useful in respecting the professional autonomy of participants by not pressing too hard for collaboration, but allowing them as individuals to select relevant learning from and about each other for themselves. History indicates that collaboration is not new and the specific, specialized contributions of professionals have a long history in holding the organization of health care services together. The organizational skills of nurses and others should not be lost but should be fostered carefully so that they are not damaged but included in an atmosphere of non-exclusion of all interested stakeholders in the National Health Service. The authors recommend that the best practices of shared learning in multiprofessional programmes be extended to benefit consumers, administrators and politicians in joint initiative programmes which could be of benefit to all.

Cooperative Behavior↗
PubMed1991

Role of emergency medical services.

For thrombolytic therapy to be effective in the treatment of acute myocardial infarction, the patient must enter the health care center delivery system in an efficient manner. Some entry delays are due to patient decisions and interactions with others. In the United States, prehospital care is delivered by a variety of different systems, varying from public service types such as fire-department based to private types of service. These personnel vary in level of training from paramedics with a high level of training to Emergency Medical Technicians-Ambulance with basic training (first aid), even less in some areas. The training should be upgraded so that training as an emergency medical technician with the ability to defibrillate would be the minimum level for emergency ambulance personnel; wherever economically and logistically feasible, ambulance personnel should be paramedics. Although the 911 emergency telephone system exists in some areas, there is no centralized, universal system for access, causing confusion and delays in obtaining care in critical situations such as cardiac arrest. There is a need for a national emergency number--911--with the ability to identify the calling number and address. Since dispatchers have little medical dispatch training, needed instructions are not given to the caller, which can reduce the patient's chance of survival. Trained dispatchers are needed to dispatch resources efficiently and to offer assistance until trained rescuers arrive. Ambulances are inefficiently located in some areas of the United States, slowing response to the patient.(ABSTRACT TRUNCATED AT 250 WORDS)

Emergency Medical Service Communication Systems↗
PubMed1989

Effect of varying drop size on the efficacy and safety of a topical beta blocker.

We studied the effects on efficacy and safety of varying the drop size of a topical solution of levobunolol 0.5%. In a double-masked, crossover acute study, we administered a single drop of either 35 microL of vehicle, or 20, 35, or 50 microL of levobunolol one hour before the subjects began a ten-minute treadmill challenge electrocardiogram. After exercise the mean heart rate was 111 beats per minute (bpm) in the vehicle group and 102 to 103 bpm in the three levobunolol groups, which were significantly different from the control group but not from each other. In a randomized double-masked, parallel, chronic study, 117 patients with elevated intraocular pressure (IOP) instilled one of the three drop sizes of levobunolol twice daily for three months. Mean decreases in IOP ranged from 5.1 to 6.0 mmHg in the three groups, not significantly different from each other in mean IOP, heart rate, or blood pressure. We conclude that drop size in the range tested had no clinically significant effect on either efficacy or safety of a beta blocker such as levobunolol.

Administration, Topical↗
PubMed1986

Some issues concerning transdermal nitroglycerin patches.

There is sufficient evidence to suggest that the duration of action of transdermal nitroglycerin patches is between 20 and 26 hours, as measured by exercise testing. At 24 hours there may be some patient variability, particularly with lower doses; however, the majority of patients show an increase in exercise time at 24 hours. In studies of the same patients, higher doses of transdermal nitroglycerin resulted in greater increases in exercise time, suggesting that higher doses may be more effective and that titration to higher doses is desirable. However, there is insufficient information from the chronic studies reported in the literature to draw any definitive conclusions. In the only crossover comparative studies reported in the literature to date, transdermal nitroglycerin appears to be as effective as isosorbide dinitrate and nifedipine. While transdermal nitroglycerin patches appear to be an effective mode of therapy, further studies are needed to confirm these findings.

Administration, Topical↗
PubMed1986

Education and evaluation in emergency cardiac care programs (CPR and advanced cardiac life support): state of the art.

To increase the survival rate for out-of-hospital cardiac arrest, improvements in training must be made so that lay rescuers are motivated and have the ability to get involved. To overcome some of the fear and lack of involvement, better education strategies are needed. Adults learn didactic information through understanding and skills through repetition and reinforcement. Due to the fact that there is limited time that adults will commit to learning CPR, methods of simplification of the techniques need to be used so that there can be sufficient repetition and reinforcement. Teaching two-rescuer CPR to lay rescuers should not routinely be done. Most adults, particularly those around high-risk individuals, should learn one-rescuer CPR. Infant resuscitation should be taught predominantly to those around small children. Methods of reinforcement through the mass media should be attempted on a routine basis. Whenever possible the courses should be spread over a period of time to allow for repetition and reinforcement, thereby maximizing learning. Advanced cardiac life support (ACLS) should be widely taught to health professionals. ACLS instruction needs to be spread over time, whenever logistically possible, to enhance learning and retention. Good, validated examinations are needed and should be routinely rotated. Better methods of evaluation are needed to look at the benefit of these types of programs and to improve the cost-benefit ratio.

Educational Measurement↗
PubMed1986

Emergency medical service systems in acute cardiac care: state of the art.

Over the last two decades, emergency medical services in the United States have been greatly improved. Organization of prehospital providers of health care has improved the outcome of many patients, particularly the trauma patient and the acute cardiac patient. In Seattle as many as 40% of outside-the-hospital cardiac arrest victims with ventricular fibrillation have been saved when there is rapid delivery of basic life support by first responders followed by advanced life support by paramedics. Although these systems are growing and improving health care, many lack adequate medical control or physician involvement. Emergency medical service systems must have physicians involved in their management to meet their full capabilities. It has become apparent that four factors are critical in determining the ability to resuscitate an individual once a cardiac arrest has occurred: time to starting any of the rescue procedures, use of electrical defibrillation when indicated, use of epinephrine, and adequacy of the technique of basic life support, particularly the ventilation component. To provide defibrillation at the earliest possible time, defibrillation by first responders such as emergency medical technicians appears to be of benefit. With the advent of automatic and semiautomatic defibrillators, first responders and family members may also be able to defibrillate victims. The use of defibrillation by people with less training than paramedics, however, must be approached with caution to ensure that there is adequate medical control and that the individuals who use these devices are properly trained.

Electric Countershock↗
PubMed1985

Cardiovascular effects of topical beta-blockers during exercise.

In two different medical centers, a total of 24 normal individuals (mean age, 31 years) participated in a double-masked, three-way crossover single-instillation comparison of betaxolol 1%, timolol 0.5%, and placebo. After each ocular treatment, cardiovascular characteristics were measured during ten-minute treadmill exercise periods. No significant differences in heart rate or double product (heart rate X systolic pressure) were seen between treatment with betaxolol and administration of placebo. However, when the same subjects were treated with timolol, they demonstrated significant (P less than .05) reductions in these values at various measurement times compared with placebo and betaxolol treatments. No significant differences in mean arterial pressure were detected after any of the treatments.

Adult↗
PubMed1985

Function of mature coronary collateral vessels and cardiac performance in the exercising dog.

Formation of extensive collateral vessels after chronic constriction of a coronary artery in dogs can provide for similar increases in blood flow to native and collateralized regions of myocardium during exertion. Previous investigations have not compared myocardial blood flow and cardiac functional responses during exercise in constricted and nonconstricted (sham) animals. Thus we evaluated left ventricular performance and myocardial blood flow at rest and during mild, moderate, and severe exertion in sham-operated dogs and in dogs 2-3 mo after placement of an Ameroid occluder around the proximal left circumflex artery. Changes in double product, maximal left ventricular dP/dt, and pressure-work index were similar in both groups for each level of exertion. Despite similar increases in estimated myocardial O2 demand and similar diastolic perfusion pressures, average transmural myocardial blood flow increased less in the constrictor animals, particularly during severe exercise (2.74 +/- 0.22 vs. 1.45 +/- 0.29 ml X min-1 X g-1). The smaller increases in blood flow occurred equally in native and collateralized regions as well as in the papillary muscles and boundary areas between the native and collateralized regions. The differences in flow in the native and collateralized regions were uniform across the wall of the myocardium. We also observed smaller increases in stroke volume and cardiac output in the constrictor group, disparities which increased with increasing exertion (stroke volume, severe exercise = 0.92 +/- 0.13 vs. 0.53 +/- 0.09 ml/kg). We postulate that myocardial active hyperemia is limited either because the coronary vessels remaining after chronic circumflex occlusion cannot dilate sufficiently or that there is inappropriate active vasoconstriction during severe exertion.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

Criteria for selecting paramedic trainees.

The experience of training more than 700 paramedics and the detailed records of 221 paramedic students were reviewed to determine possible criteria for selecting individuals who could complete successfully a paramedic course. Individuals over 35 years of age who had not taken competitive examinations or college courses within the last 15 years faired poorly. Review of total college hours, college grade point average (GPA), science hours, and science GPA showed no difference between the group that passed paramedic school and the group that failed. Fire department rookie school grades and emergency medical technician-basic (EMT-A) grades correlated well with success or failure in paramedic school. Psychological screening was important in ruling out serious psychiatric disturbances but was of uncertain help in predicting early burnout.

Allied Health Personnel↗
PubMed1982

Passive leg raising does not produce a significant or sustained autotransfusion effect.

Passive leg raising is widely used to treat hypotension associated with hypovolemia. Presumably gravity causes a central translocation of leg venous blood and an increase in filling pressure, cardiac output, and arterial pressure. Ten healthy volunteers, 25 to 35 years old, had measurements of heart rate, blood pressure, and cardiac output in the supine position after 20 sec and 7 min of 60 degrees passive leg elevation. The protocol was performed 3 and 45 min after the subjects changed from an ambulatory upright to a supine position. Stroke volume and cardiac output increased transiently (8-10%) when the legs were raised after 3 min rest in the supine position. By 7 min of leg elevation, these beneficial effects disappeared. After 45 min supine, leg raising had no effect on stroke volume or cardiac output but increased blood pressure (4 mm Hg) by increasing peripheral resistance (15%). Thus, leg raising, like application of the MAST trousers, fails to produce any sustained increase in cardiac output or stroke volume. Small venous leg volumes and time-dependent changes in the distribution of venous volume and compliance may explain the absence of any sustained 'autotransfusion' effect.

Adult↗
PubMed1981

Hemodynamic effects of Medical Anti-Shock Trousers (MAST garment).

Despite widespread use of the Medical Anti-Shock Trousers (MAST) little is known about the exact mechanism by which they increase arterial pressure. It is assumed that an autotransfusion occurs. To examine this question, blood pressure, heart rate, forearm blood flow, cardiac output, and stroke volume were measured in ten healthy adults, supine and during 60 degree headup tilt with MAST garment pressures of 409 and 100 mm Hg. Supine, the garment produced no net 'autotransfusion,' but raised blood pressure (27%) by increasing peripheral resistance (48%) with decreased stroke volume and cardiac output (18%). During headup tilt without the MAST device, venous pooling in the legs decreased stroke volume (52%), cardiac output (30%), and increased total peripheral resistance (40%). Application of the garment during tilt shifted this blood centrally, producing increased stroke volume (52%), cardiac output (30%), and increased total peripheral resistance (40%). Application of the garment during tilt shifted this blood centrally, producing increased stroke volume (14%). In supine normovolemic subjects, the garment raised pressure almost exclusively by increased systemic afterload. Forearm vascular resistance did not change and the increased pressure augmented flow to the arm, i.e., to noncompressed tissue. With increased venous pooling during tilt, the MAST garment acted as a 'G-suit' and caused a central shift of blood volume. These findings could explain: 1) why fluid replacement is not always adequate to maintain pressure when deflating the trousers; 2) why the trousers should not be used if one wishes to avoid increasing afterload (e.g., certain patients with acute myocardial infarction). We conclude that the MAST garment acts as a local, effective, nonpharmacologic vasoconstrictor and should be used when such an effect is clinically appropriate.

Adolescent↗