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Biomedical subjects

E R Eichner

Publications and source records attributed to E R Eichner.

At least 19 recordsLinked to original sources
PubMed2000

Blood volume: importance and adaptations to exercise training, environmental stresses, and trauma/sickness.

This paper reviews the influence of several perturbations (physical exercise, heat stress, terrestrial altitude, microgravity, and trauma/sickness) on adaptations of blood volume (BV), erythrocyte volume (EV), and plasma volume (PV). Exercise training can induce BV expansion: PV expansion usually occurs immediately, but EV expansion takes weeks. EV and PV expansion contribute to aerobic power improvements associated with exercise training. Repeated heat exposure induces PV expansion but does not alter EV. PV expansion does not improve thermoregulation, but EV expansion improves thermoregulation during exercise in the heat. Dehydration decreases PV (and increases plasma tonicity) which elevates heat strain and reduces exercise performance. High altitude exposure causes rapid (hours) plasma loss. During initial weeks at altitude, EV is unaffected, but a gradual expansion occurs with extended acclimatization. BV adjustments contribute, but are not key, to altitude acclimatization. Microgravity decreases PV and EV which contribute to orthostatic intolerance and decreased exercise capacity in astronauts. PV decreases may result from lower set points for total body water and central venous pressure, while EV decreases may result from increased erythrocyte destruction. Trauma, renal disease, and chronic diseases cause anemia from hemorrhage and immune activation which suppresses erythropoiesis. The re-establishment of EV is associated with healing, improved life quality, and exercise capabilities for these injured/sick persons.

Adaptation, Physiological↗
PubMed2000

American College of Sports Medicine roundtable. The physiological and health effects of oral creatine supplementation.

Creatine (Cr) supplementation has become a common practice among professional, elite, collegiate, amateur, and recreational athletes with the expectation of enhancing exercise performance. Research indicates that Cr supplementation can increase muscle phosphocreatine (PCr) content, but not in all individuals. A high dose of 20 g x d(-1) that is common to many research studies is not necessary, as 3 g x d(-1) will achieve the same increase in PCr given time. Coincident ingestion of carbohydrate with Cr may increase muscle uptake; however, the procedure requires a large amount of carbohydrate. Exercise performance involving short periods of extremely powerful activity can be enhanced, especially during repeated bouts of activity. This is in keeping with the theoretical importance of an elevated PCr content in skeletal muscle. Cr supplementation does not increase maximal isometric strength, the rate of maximal force production, nor aerobic exercise performance. Most of the evidence has been obtained from healthy young adult male subjects with mixed athletic ability and training status. Less research information is available related to the alterations due to age and gender. Cr supplementation leads to weight gain within the first few days, likely due to water retention related to Cr uptake in the muscle. Cr supplementation is associated with an enhanced accrual of strength in strength-training programs, a response not independent from the initial weight gain, but may be related to a greater volume and intensity of training that can be achieved. There is no definitive evidence that Cr supplementation causes gastrointestinal, renal, and/or muscle cramping complications. The potential acute effects of high-dose Cr supplementation on body fluid balance has not been fully investigated, and ingestion of Cr before or during exercise is not recommended. There is evidence that medical use of Cr supplementation is warranted in certain patients (e.g.. neuromuscular disease); future research may establish its potential usefulness in other medical applications. Although Cr supplementation exhibits small but significant physiological and performance changes, the increases in performance are realized during very specific exercise conditions. This suggests that the apparent high expectations for performance enhancement, evident by the extensive use of Cr supplementation, are inordinate.

Adult↗
PubMed1998

Treatment of suspected heat illness.

1. Despite advances in the art and science of fluid balance, exertional heat illness -- even life-threatening heat stroke -- remains a threat for some athletes today. 2. Risk factors for heat illness include: being unacclimatized, unfit, or hypohydrated; certain illnesses or drugs; not drinking in long events; and a fast finishing pace. 3. Heat cramps typically occur in conditioned athletes who compete for hours in the sun. They can be prevented by increasing dietary salt and staying hydrated. 4. Early diagnosis of heat exhaustion can be vital. Early warning signs include: flushed face, hyperventilation, headache, dizziness, nausea, tingling arms, piloerection, chilliness, incoordination, and confusion. 5. Pitfalls in the diagnosis of heat illness include: confusion preventing self-diagnosis; the lack of trained spotters; rectal temperature not taken promptly; the problem of "seek not, find not;" and the mimicry of heat illness. 6. Heat stroke is a medical emergency. Mainstays of therapy include: emergency on-site cooling; intravenous fluids; treating hypoglycemia as needed; intravenous diazepam for seizures or severe cramping or shivering; and hospitalizing if response is slow or atypical. 7. The best treatment is prevention. Tips to avoiding heat illness include: rely not on thirst; drink on schedule; favor sports drinks; monitor weight; watch urine; shun caffeine and alcohol; key on meals for fluids and salt; stay cool when you can; and know the early warning signs of heat illness.

Acclimatization↗
PubMed1995

Overtraining: consequences and prevention.

Overtraining refers to prolonged fatigue and reduced performance despite increased training. Its roots include muscle damage, cytokine actions, the acute phase response, improper nutrition, mood disturbances, and diverse consequences of stress hormone responses. The clinical features are varied, non-specific, anecdotal and legion. No single test is diagnostic. The best treatment is prevention, which means (1) balancing training and rest, (2) monitoring mood, fatigue, symptoms and performance, (3) reducing distress and (4) ensuring optimal nutrition, especially total energy and carbohydrate intake.

Affect↗
PubMed1993

Ergolytic drugs in medicine and sports.

Just as drugs that enhance exercise capacity and/or athletic performance are often called "ergogenic," drugs that impair these functions can be termed "ergolytic." Today's athletes hear too much about the former and too little about the latter. Ergolytic drugs used today by certain athletes include alcohol, marijuana, smokeless tobacco, cocaine, antihypertensives, eye drops, and diuretics. Some antidepressants, too, can be ergolytic, as well as some antihistamines and other common drugs--even caffeine--in some settings, for some people. Internists can help their fitness-minded patients by educating them about ergolytic drugs and by tailoring their management to foster peak performance at work and play.

Adult↗
PubMed1992

Sports anemia, iron supplements, and blood doping.

1) Athletes tend to have lower hemoglobin concentrations than sedentary counterparts. This has been called sports anemia, a misnomer. 2) Sports anemia is a false anemia and a beneficial adaptation to aerobic exercise, caused by an expanded plasma volume that dilutes red blood cells. 3) Athletes, however, can also develop true anemia, most commonly caused by iron deficiency. True anemia curbs athletic performance, but nonanemic iron deficiency does not. 4) Iron supplements are useful for women endurance athletes who repeatedly develop iron deficiency anemia despite dietary advice. 5) Some endurance athletes today are blood doping by abusing recombinant human erythropoietin (rEPO). They risk dying to win.

Anemia, Hypochromic↗
PubMed1991

Hematuria in a young recreational runner.

A 27-year-old recreational jogger developed gross hematuria following a 2-mile run. Evaluation revealed a transitional cell carcinoma of the bladder. Etiologies for pigmenturia and the pathogenesis of exertional hematuria are reviewed. The need to exclude other causes of hematuria before attributing the finding to exercise is emphasized.

Carcinoma, Transitional Cell↗
PubMed1990

Exercise and arthritis. The hematology of inactivity.

Arthritis tends to promote inactivity, and inactivity tends to promote an unhealthful constellation of blood abnormalities that increases the risk of heart attack and stroke. The hematology of inactivity comprises the following: low plasma volume, high hematocrit, high plasma fibrinogen, elevated blood viscosity, increased platelet aggregability, and diminished fibrinolysis. Regular exercise reverses all these adverse blood changes and, thereby, helps prevent heart attack and stroke. Simply put, exercise "improves" the blood, making it flow more easily and clot less readily. This "healthy hematology of exercisers" is one more reason why prudent exercise is as vital for patients with arthritis as it is for the rest of us.

Arthritis↗
PubMed1988

Sudden death in racquet sports.

The regular playing of racquet sports tends to confer general health and to protect the heart--to produce the athletic heart syndrome. Strenuous play, however, can provoke ventricular arrhythmias and can kill individuals with heart disease. The overall risk for an exercise death from racquet sport play seems to be as low as from distance running. Middle-aged men, however, especially those with known coronary disease or coronary risk factors, should approach racquet sports with caution, and might benefit from timely medical advice.

Age Factors↗
PubMed1988

Alcohol, stroke and coronary artery disease.

It is widely believed that alcohol use in moderation helps prevent coronary artery disease, but the epidemiologic and experimental support for this concept is mixed and controversial. The controversy has been fueled by new reports on the effect of alcohol on lipoprotein subfractions, on the risk of stroke and on the risk of coronary events. Continued support for the belief that moderate alcohol use has a "protective" effect should be based on stronger evidence than is now at hand.

Alcohol Drinking↗
PubMed1987

Antithrombotic effects of exercise.

Regular exercise appears to have antithrombotic effects on the blood. Athlete's anemia, a dilutional pseudoanemia, enhances performance and decreases blood viscosity; it may also decrease platelet adhesion to damaged arteries. Physical conditioning may decrease platelet aggregability. Exercise activates fibrinolysis, and physical fitness seems to enhance the rate of fibrinolysis. The hematologic changes of exercise may help prevent coronary heart disease.

Anemia↗
PubMed1986

Failure to diagnose anemia in medical inpatients. Is the traditional diagnosis of anemia a dying art?

The diagnosis and treatment of anemia in medical inpatients were studied. Anemia was detected from the admitting complete blood cell count, the medical charts were perused for management of anemia by the physicians, and the cases of anemia were classified by the investigators, using the complete blood cell count and peripheral blood smear. Anemia was seldom diagnosed in the traditional manner. In about 25 percent of cases, it was not even recognized. In about 20 percent, it was recognized but not evaluated or treated. In the 55 percent of cases adequately diagnosed and/or treated, the diagnosis was often more "situational" than analytic, the treatment more empiric than specific. Physicians ignored or misused information from the complete blood cell count and smear description and examined the smear themselves in fewer than one in 10 anemic patients. Not all of the missed cases of anemia were mild, expected from the patient's illness, or unimportant to the patient's care.

Anemia↗
PubMed1986

Endurance swimming, intravascular hemolysis, anemia, and iron depletion. New perspective on athlete's anemia.

Swimmers were evaluated for the anemia, intravascular hemolysis, and iron deficiency reported in endurance runners. Plasma concentrations of ferritin, haptoglobin, and hemoglobin were measured in nine collegiate swimmers through the competitive season and in 23 adult swimmers before and after endurance races of 1.5 km to 10 km. About 10 percent of the swimmers had low hemoglobin concentrations. The severity of this "swimmer's anemia" correlated with the amount of swimming in both men and women. Intravascular hemolysis occurred during all the races; the fastest swimmers in the longest races had the greatest decreases in haptoglobin. About 25 percent of the swimmers had low baseline haptoglobin concentrations. Iron depletion was found in 11 percent of the men and 57 percent of the women, but their athletic performance was not notably impaired. Iron depletion, anemia, and intravascular hemolysis in athletes in a nontraumatic sport suggest that mechanisms other than footstrike are components of athlete's hemolysis.

Adolescent↗
PubMed1985

Alcohol versus exercise for coronary protection.

Both alcohol and exercise have been said to protect against coronary heart disease. The epidemiologic data suggest exercise, per se, does, but alcohol, per se, does not protect against coronary heart disease. Recent longitudinal data suggest teetotalers, especially those who have never smoked, have the lowest coronary heart disease mortality of all. Other cross-sectional and longitudinal studies that suggest light drinkers have the lowest coronary heart disease mortality may be biased because: (1) the teetotalers include some ex-drinkers who may have quit drinking because of coronary heart disease; and (2) the light drinkers include some who drink very rarely, and/or drink very small amounts, and/or have a lower risk of coronary heart disease independent of alcohol because they are more health-conscious in general. The metabolic data also suggest exercise, but not alcohol, protects against coronary heart disease. Exercise increases the level of high-density lipoprotein 2, which correlates well with coronary heart disease risk; alcohol in moderation seems to increase the level of high-density lipoprotein 3, which correlates poorly with coronary heart disease risk and may merely reflect hepatic enzyme induction. Exercise and alcohol influence blood pressure, body weight, and glucose tolerance in opposite directions; in each instance, the influence of exercise is beneficial, that of alcohol detrimental, to the prevention of coronary heart disease. There seems to be no reason to use alcohol for coronary protection.

Alcohol Drinking↗
PubMed1985

Runner's macrocytosis: a clue to footstrike hemolysis. Runner's anemia as a benefit versus runner's hemolysis as a detriment.

This report of a runner in whom progressive macrocytosis developed with increasing mileage deals with the hematologic adaptations to exercise, introduces the concept of "runner's macrocytosis" as a compensated hemolysis of older red cells, and makes a case for "runner's anemia" as a benefit versus "runner's hemolysis" as a detriment. It presents the characteristic hematologic profile of footstrike hemolysis and explores the influence of racing, different levels of training, and different shoes. It shows that runner's hemolysis can be reduced by reducing mileage but not necessarily by changing shoes, and it suggests that runner's hemolysis can impair race performance by preventing the attainment of an optimal red cell mass and, in time, by evolving into iron-deficiency anemia.

Adult↗