Sodium balance during U. S. football training in the heat: cramp-prone vs. reference players.

U. S. football players with a history of heat cramps were evaluated for the effect of physical training, sodium intake, and loss of sweat sodium on whole blood sodium concentration (BNa). Athletes (n=14 males, 24+/-1 y) were recruited and studied based on medical history, age, and position. The reference group (R, n=8 without a cramping history) and cramp-prone group (C, n=6, history of whole-body cramps associated with extensive sweat loss during exercise in the heat) were measured for body mass and BNa (ISTAT) before and after team training of 2.2 h in hot conditions (WBGT=29-32 degrees C). Intake and loss of fluid and sodium were also measured to determine respective acute balance. In R, BNa was stable pre- to post-training (138.9+/-1.8 to 139.0+/-2.0 mmol/L) while it tended to decline in C (137.8+/-2.3 to 135.7+/-4.9 mmol/L), and three subjects in C had BNa values below 135 mmol/L (131.7+/-2.9 mmol/L). C consumed a greater percentage of total fluid as water (p<0.05). Mean sweat sodium concentration was (52.6+/-29.2 mmol/L for C and 38.3+/-18.3 mmol/L for R (p>0.05). Compared to R, C tended to experience a decline in BNa and greater acute sodium imbalance. These changes may place cramp-prone players at greater risks for developing acute sodium deficits during training.

Effect of alcohol on serum folate level.

Alcohol was given orally and intravenously to normal and chronic alcoholic volunteers to study its effect on folate metabolism. Oral alcohol, given to nine subjects on a low folate diet, caused a greater fall in serum Lactobacillus casei folate levels than that seen in eight subjects on a low folate diet alone. This alcohol-induced fall in serum folate level occurred largely during the 1st day of the protocol. Although brief infusions of intravenous ethanol had no effect on serum folate level, a 13 h infusion caused a striking fall in serum folate level between the 8th and 10th h. When ethanol was stopped, the serum folate level returned rapidly to normal. Two chronic alcoholic subjects with different basal levels of serum folate were studied for several weeks on a low folate diet plus alcohol. The serum folate level fell promptly in each subject, rose when alcohol was temporarily stopped, and fell when alcohol was resumed. Folate-deficient megaloblastic anemia developed in 3 wk in the subject with initially marginal serum folate levels, but failed to develop in almost 7 wk in the subject with normal folate stores, as reflected by initially high serum folate levels. Thus, the alcohol-induced fall in serum folate level was apparently not a result of depletion of folate stores. In vitro experiments ruled out an assay artifact as an explanation for the alcohol-induced fall in serum L. casei folate level. It seems likely that alcohol interferes with the delivery of n-5-methyltetrahydrofolic acid from storage areas.

Folic acid binding protein and folate balance in uremia.

To determine the incidence and importance of folate deficiency in uremia, we studied 41 patients who had chronic uremia but who were not receiving hemodialysis. Serum folate level was assayed by microbiological, whole serum radioassay, and heat-extracted radioassay techniques. Mean serum folate level, as determined with the Lactobacillus casei method, was 6.9 ng/ml (normal, more than 3.0 ng/ml). The mean heat-extracted radioassay serum folate level was 6.6 ng/ml. Only 10% of our patients had subnormal serum folate values, as determined with these techniques. No cases of megaloblastic anemia were discovered, and the hematologic profiles correlated with L casei and heat-extracted radioassay serum folate values. The mean serum folic acid binding protein (FABP) level was significantly greater for the uremic patients than for control patients (26% vs 9.9%, respectively; P = .0005). Our results show that elevated levels of serum FABP spuriously depress the serum folate level, as determined with the whole serum radioassay technique, but apparently do not retard delivery of folate to the tissue in vivo.

Elevated serum levels of unsaturated folate binding protein: clinical correlates in a general hospital population.

We measured the capactiy of unsaturated folate binding protein to bind 3H-pteroylglutamic acid (UFBC) in serums from 489 general hospital patients. Of the patients 20% had mild-to-moderate elevations in UFBC (250 to 500 pg/ml), but only 6% had marked elevations (greater than 650 pg/ml), which correlated with metastatic cancer, active granulomatous disease, and especially with liver disease. The poor correlation of serum UFBC with folate status of the patient suggests that in many instances the elevated serum UFBC is neither the consequence nor the cause of folate deficiency. Although the role of folate binding protein remains unknown, it may be primarily an intracellular protein that is released into the serum as an index of activity of liver cells, granulocytes, and perhaps certain cancer cells.

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.

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.

Platelets, carotids, and coronaries. Critique on antithrombotic role of antiplatelet agents, exercise, and certain diets.

"Antiplatelet" drugs and certain life styles seem to have an "antithrombotic" effect that may help protect against stroke and heart attack. This review of the experience with aspirin, dipyridamole, and sulfinpyrazone offers new interpretations of some of the major clinical trials, suggests guidelines for use of antiplatelet drugs, and integrates novel observations on diet and exercise into the "thromboxane-prostacyclin balance" hypothesis. It is argued that the Canadian stroke study showed that aspirin protects men with transient ischemic attacks from coronary death as well as from stroke, that type II errors may have been made in some clinical trials, that aspirin protects women as well as men, that aspirin benefits patients who have had a heart attack, that the effect of aspirin in angina varies with the type of angina, that the dose of aspirin used may not be critical, that guidelines for use of dipyridamole and sulfinpyrazone are still inconclusive, and that exercise and fish oil supplements may be "antithrombotic."

Exercise and heart disease. Epidemiology of the "exercise hypothesis".

The "exercise hypothesis" states that exercise protects against coronary heart disease. Reviewed herein is the epidemiologic evidence for and against the "exercise hypothesis." The weight of evidence supports the view that exercisers have a lower risk of coronary disease, but that vigorous exercise cannot always prevent progression of coronary atherosclerosis and does increase the risk of sudden death in persons with advanced coronary atherosclerosis. It is concluded that the "exercise hypothesis" is plausible, even likely, but still unproved.

Splenic function: normal, too much and too little.

This review is concerned with normal splenic function, mechanisms and consequences of splenomegaly, hypersplenism, the medical indications for splenectomy and the various aspects of hyposplenism. The potential probelm of lethal septicemia in hyposplenic or asplenic patients is also considered.

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.

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.

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.

Clinical usefulness of polymorphonuclear leukocyte vacuolization in predicting septicemia in febrile children.

Vacuolization of the polymorphonuclear leukocyte (PMN) has generally been regarded as an indication of bacterial infection and has been particularly useful in diagnosing septicemia. In an effort to predict septicemia, peripheral blood smears from 69 febrile children were examined and systematically scored for severity of vacuolization. Thirteen children had remarkable vacuolization compared to the others. These 13 included only five children with bacterial illnesses and only one of the seven children with septicemia. Our finding that PMN vacuolization was neither diagnostic of septicemia nor predictive of bacterial infection suggests that the specificity of the link between vacuoles and bacteremia needs to be reassessed.

Spider bite hemolytic anemia: positive Coombs' test, erythrophagocytosis, and leukoerythroblastic smear.

The full hematologic profile of spider bite hemolytic anemia has not been documented in the literature. The two patients had brisk intravascular hemolysis with direct Coombs' tests positive for complement and with peripheral blood smears showing spherocytosis, erythrophagocytosis, and leukoerythroblastosis. The author's experience, along with that in the literature reviewed herein, suggests that the hemolytic anemia that can follow the bite of the brown recluse spider could be confused with autoimmune hemolytic anemia.

Erythroid karyorrhexis in the peripheral blood smear in severe arsenic poisoning: a comparison with lead poisoning.

Three men with severe arsenic poisoning were hospitalized with working diagnoses, respectively, of peptic ulcer, pancreatitis, and viral gastroenteritis. In the first two patients, correct diagnosis was delayed until the return of heavy-metal screening tests ordered because of painful peripheral neuropathy in one and sudden flaccid paralysis, resembling Guillain-Barré syndrome, in the other. Both patients had coarsely stippled red blood cells with markedly abnormal nuclei in their peripheral blood smears. These distinctive hematologic features led to an early diagnosis in the third patient. The author's review of past cases of lead poisoning showed that red blood cell karyorrhexis also tends to occur in patients who consume illicit whiskey ("moonshine"). Karyorrhexis or marked dyserythropoiesis in the peripheral smear, not heretofore described in arsenic or lead poisoning, may indeed be a unique hematologic clue. Scrutiny of the peripheral blood and/or buffy coat smear in patients with perplexing gastrointestinal or neurologic symptoms may enable earlier diagnosis and better therapy of arsenic poisoning.

Adult T-cell leukemia: clinical and immunologic characterization of a nonendemic case.

A 56-year-old black man with nonendemic adult T-cell leukemia is reported, who presented with severe hypercalcemia and leukemic leptomeningeal infiltration but had no evidence of bone marrow involvement. His malignant cells were characterized by light and transmission electron microscopy, cytogenetics, and flow cytometry. The cells demonstrated the deeply indented or convoluted nuclei characteristic of endemic human T-cell lymphoma virus-associated cases. Surface phenotyping indicated the cells' origin to be from the mature, helper/inducer subset of T-lymphocytes. However, there was no clinical or laboratory evidence that the malignant cells retained immunoregulatory function. The clinical and immunologic features of this and other nonendemic cases are compared with those of patients from the endemic regions of Japan, the Caribbean islands, and the southeastern United States.

Acute leukemia after successful chemotherapy for oat cell carcinoma.

A report of acute myelomonocytic leukemia following successful therapy for oat cell carcinoma is presented. The patient had been treated with extensive cytotoxic and radiation therapy, and was without clinical evidence of disease at one year follow-up. Eighteen months later, a peripheral smear revealed numerous blasts with monocytoid characteristics. This unusual presentation is discussed and compared with several other cases appearing in the recent literature.

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.

Immunology and exercise. Physiology, pathophysiology, and implications for HIV infection.

This article covers the latest information on the immunologic changes of exercise as well as the effects of regular exercise on persons infected with HIV and the exercise recommendations for HIV-infected athletes. Included are discussions about psychoneuroimmunology and exercise-associated changes in immunity.

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.