Left ventricular hypertrophy in athletes: an exercise-echocardiographic study

Left ventricular dimensions measured by M-mode echocardiography of 10 distance runners and 10 wrestlers were compared to 10 sedentary controls at rest and during 12 min of semisupine, graded bicycle ergometer exercise. At rest, runners and wrestlers demonstrated greater left ventricular mass compared to controls (mean values, 311.8 and 325.9 vs 215.9 g, respectively: P less than 0.05). In wrestlers, this was due to increased left ventricular septal (13.5 mm) and posterior wall thickness (12.9 mm) compared to controls (9.1 and 10.1 mm, respectively: P less than 0.05). In runners, this was due to increased left ventricular end-diastolic dimension (55.8 mm) compared to controls (49.7 mm) (P less than 0.05). During exercise, the different patterns noted at rest among the three groups in left ventricular dimensions and function persisted and were preserved: runners maintained a higher end-diastolic dimension compared to wrestlers and controls and greater shortening dimension compared to wrestlers. Absolute changes in left ventricular parameters from rest to exercise were not significantly different among the three groups.

CONCLUSIONS

1) different patterns of left ventricular hypertrophy exist among different types of athletes, with mainly increased wall thickness in primarily statically trained athletes and increased volume in dynamically trained athletes; and 2) these differences observed at rest persist during moderate-intensity, semisupine ergometer exercise and have direct functional significance, thereby emphasizing the differences found in cardiac dimensions among different types of athletes.

Clinical pharmacokinetics of high-dose metoclopramide in cancer patients receiving cisplatin therapy

Using a sensitive and specific high-pressure liquid chromatographic (HPLC) assay, we measured serum levels of metoclopramide in 18 cancer patients receiving high-dose intravenous (IV) therapy to prevent cisplatin-induced emesis. Ten patients were treated with one or more courses with metoclopramide alone (1.0 to 3.0 mg/kg) in an open-label study, and eight patients were treated with a fixed 2.0 mg/kg dose of metoclopramide with or without adjunct dexamethasone (20 mg) using a randomized, crossover design. The pharmacokinetics of metoclopramide were determined, and the relationship between serum levels and clinical response was evaluated. The pharmacokinetic parameters of high-dose metoclopramide were found to be similar to those reported for standard promotility doses, and no dose dependency was demonstrated over the range of doses studied. No clear correlation between serum metoclopramide levels and prevention of cisplatin-induced emesis was observed. The addition of dexamethasone resulted in clinical improvement in two of eight patients, but had no effect on serum metoclopramide levels or kinetic parameters. Results in this study population do not show metoclopramide levels to be related to antiemetic effect following IV cisplatin therapy.

Lethal atherosclerosis associated with abnormal plasma and tissue sterol composition in sitosterolemia with xanthomatosis

Tissue sterol composition was determined in an 18-year-old male with sitosterolemia with xanthomatosis who died suddenly and whose coronary and aortic vessels showed extensive atherosclerosis and, for comparison, in an 18-year-old male with minimal atherosclerosis who died accidently. Sterols in the control tissues (plasma, erythrocytes, cardiac muscle, lung, liver, aorta, and brain) contained cholesterol with only trace amounts of cholestanol. In contrast, sterols in corresponding tissues of the sitosterolemic subject (except brain) were composed of cholesterol, increased amounts of plant sterols, campesterol and sitosterol, and 5 alpha-saturated stanols, cholestanol, 5 alpha-campestanol, and 5 alpha-sitostanol, that were deposited in approximately the same ratio as present in plasma. However, sitosterolemic brain sterol composition resembled that of the control brain with cholesterol and only trace amounts (less than 1%) of cholestanol and phytosterols. The sitosterolemic aorta was extensively atherosclerotic and contained more than twice the quantity of sterols as the control aorta (5.6 mg/g versus 2.6 mg/g) with increased amounts of cholesterol, plant sterols, and 5 alpha-saturated stanols. These results indicate that cholesterol, plant sterols, and 5 alpha-stanols are deposited prematurely and are associated with accelerated atherosclerosis in subjects with sitosterolemia with xanthomatosis.

Biochemical and immunocytological localization of molluscan small cardioactive peptides in the nervous system of Aplysia californica

High pressure liquid chromatography (HPLC) followed by bioassay on isolated snail hearts were used to locate two related peptides, termed small cardioactive peptides A and B (SCPA and SCPB) in each of the central ganglia of Aplysia. The peptides are most concentrated in the buccal ganglia, the ganglia involved in the control of feeding movements. Immunocytology with antisera raised to conjugated SCPB stained three groups of neurons in the buccal ganglia. One group consisted of relatively small neurons that were tightly clustered. The second group was comprised of larger neurons that were more scattered. The third group was made up of several neurons including the two largest in the ganglia, identified cells B1 and B2. B1 and B2 and other neurons in this group innervate the gut by way of the esophageal nerve. HPLC-bioassay of single, individually dissected B1 or B2 neurons demonstrated that the two peptides are present in a single cell. For B2, but not B1, choline injected into the cell body was converted to the conventional transmitter, acetylcholine. This indicates that, in addition to the two peptides, B2 also contains choline acetyltransferase, and raises the possibility that acetylcholine and the SCPs may act as co-transmitters in B2. Strong immunocytological staining of fibers and varicosities was observed in the neuropilar region of the cerebral, pleural, pedal, and abdominal ganglia. In addition to the buccal ganglia, immunoreactive neurons were observed in all of the other central ganglia. The high concentration of the SCPs and the relatively large number of immunoreactive neurons in the buccal ganglion suggest a particularly important role of these peptides specifically in feeding behavior. However, the widespread occurrence of the SCPs in fibers and neuronal cell bodies throughout the nervous system suggests that these peptides also may have additional behavioral functions in Aplysia.

A Nutritional and Hematologic Assessment of Elite Ballet Dancers

In brief: We studied the nutritional and hematologic status of 22 professional ballet dancers (10 men, 12 women, mean age 25), from American Ballet Theatre by analyzing daily dietary intake and laboratory data including blood vitamin assays. The dancers had law percent body fat. Daily calorie intake was 2,967 ± 667 kcal for men and 1,673 ± 450 kcal for women. Carbohydrate consumption (38% of the total daily calorie intake for men and 50% for women) was too law for efficient energy use. Hemoglobin and red cell indexes were normal, but serum ferritin was below normal in eight women and three men. Serum chemistry values were normal. Blood vitamin assays were normal in all dancers, reflecting widespread use of vitamin supplements. By sports medicine standards, the dancers' law calorie diets were suboptimal for strenuous physical exercise.

Effect of diltiazem on renal clearance and serum concentration of digoxin in patients with cardiac disease

The effect of diltiazem on digoxin serum concentration was evaluated in 9 patients who had been treated chronically for heart disease with digoxin, 0.25 mg/day. The indications for digoxin therapy were arrhythmias in 5 patients and mild heart failure in the other 4. Renal digoxin clearance was also evaluated in 8 of these patients. Serum digoxin concentration was measured at control, 7 +/- 2 days after initiation of 120 mg/day of diltiazem and 11 +/- 5 days after increasing the dose of diltiazem to 240 mg/day. Serum digoxin concentration was 0.9 +/- 0.4 ng/ml at control, 0.8 +/- 0.4 ng/ml with 120 mg/day of diltiazem, and 0.8 +/- 0.3 ng/ml during therapy with 240 mg/day. The differences between these values were not significant. Renal digoxin clearance also did not show a significant change after diltiazem therapy (44 +/- 15 ml/min before diltiazem and 46 +/- 13 ml/min with 240 mg/day of diltiazem). This study shows no effect of diltiazem in doses of 120 to 240 mg/day on serum digoxin concentration or renal digoxin clearance in patients who are treated chronically for heart disease with digoxin. In this dose range, diltiazem has advantages over verapamil, which markedly elevates digoxin levels.

Effects of glycine and GABA on the ganglion cels of the retina of the skate Raja erinacea

Application of glycine and GABA caused inhibition of light-evoked activity from different populations of 'ON' center ganglion cells in the retina of the skate (Raja erinacea). Cells affected by glycine were not affected by GABA and vice-versa. Addition of 100 microM strychnine to the glycine-containing perfusate caused a resumption in light-evoked responses of the cells. The action of GABA was antagonized by 100 microM bicuculline methochloride, but not by picrotoxin. Autoradiography revealed the presence of [3H]glycine accumulating amacrine cells.

Hyperuricemia in glycogen storage disease type I. Contributions by hypoglycemia and hyperglucagonemia to increased urate production

Studies were performed to determine whether hypoglycemia or the glucagon response to hypoglycemia increases uric acid production in glycogen storage disease type I (glucose-6-phosphatase deficiency). Three adults with this disease had hyperuricemia (serum urate, 11.3-12.4 mg/dl) and reduced renal clearance of urate (renal urate clearance, 1.1-3.1 ml/min). These abnormalities were improved in one patient by intravenous glucose infusion for 1 mo, suggesting a role for hypoglycemia and its attendant effects on urate metabolism and excretion. A pharmacologic dose of glucagon caused a rise in serum urate from 11.4 to 13.0 mg/dl, a ninefold increase in urinary excretion of oxypurines, a 65% increase in urinary radioactivity derived from radioactively labeled adenine nucleotides, and a 90% increase in urinary uric acid excretion. These changes indicate that intravenous glucagon increases ATP breakdown to its degradation products and thereby stimulates uric acid production. To observe whether physiologic changes in serum glucagon modulate ATP degradation, uric acid production was compared during saline and somatostatin infusions. Serum urate, urinary oxypurine, radioactivity, and uric acid excretion increased during saline infusion as patients became hypoglycemic. Infusion of somatostatin suppressed these increases despite hypoglycemia and decreased the elevated plasma glucagon levels from a mean of 81.3 to 52.2 pg/ml. These data suggest that hypoglycemia can stimulate uric acid synthesis in glucose-6-phosphatase deficiency. Glucagon contributes to this response by activating ATP degradation to uric acid.

Comparative radiopharmacokinetics of 18F-5-fluorouracil administered i.v. to rats bearing a mammary tumor

In an attempt to compare the efficacy of various 5-fluorouracil (5-FU) regimens, we studied the kinetics of 18F-labeled and unlabeled 5-FU in rats. 18F-5-FU was synthesized in our laboratory and was administered in tracer doses to Fischer rats bearing either the 13762 or the R3230 mammary adenocarcinoma, and to Sprague-Dawley rats bearing the Walker-256 carcinosarcoma, with or without pre-treatment with a therapeutic dose of unlabeled 5-FU. In addition, the non-radioactive 5-FU was administered to control rats of both strains. All animals were followed for 70 min either by measuring their 18F blood levels continuously using an extracorporeal blood-loop, or by determining their 5-FU blood levels at discrete time intervals. The biphasic kinetic profile was characterized by determining alpha and beta rate constants and their corresponding half-lives. Differences in 18F elimination, as measured by the area under the curve during the elimination phase, were observed between the pre-treated 13762-bearing rats and the untreated group bearing the same tumor, as well as the pre-treated non-tumored controls and both W-256-bearing groups. Such differences could reveal changes in the ability of those rats to metabolize 5-FU, and hence correlate to the level of active metabolite(s) available to their tumor sites.

Effect of actinomycin D on iodide transport in FRTL-5 thyroid cells

TSH-induced I- uptake in FRTL-5 thyroid cells requires new protein synthesis. During the induction of I- uptake, which takes nearly 60 h to reach its maximum, two waves of protein synthesis can be identified: one during the first 8 h and another after 24-30 h, each involving different proteins. Cycloheximide (CH) added during the first 10 h of a 48-h incubation with TSH completely inhibits the induction of I- uptake; 58% inhibition is observed with CH added at 24 h; no inhibition is observed when CH is added 36 h after TSH. Like CH, actinomycin D (ActD), added at the beginning of the 48-h period, inhibits TSH induction of I- uptake; partial inhibition (83%, 72%, and 28%) is observed when ActD is added at 1, 5, and 10 h, respectively. Treatment with ActD at 24 h (ActD-treated cells), however, paradoxically increases I- uptake (1.8- to 3.5-fold over the control value). The characteristics of I- uptake in ActD-treated cells are the same as those in untreated cells; both are Na+ dependent and can be inhibited in a comparable manner by anions. Kinetic measurements of I- transport indicate that ActD increases the rate of I- influx (2-fold or greater increase in maximum velocity without a significant change in Km), with only minor changes in I- release. Enhanced I- uptake in ActD-treated cells is inhibited by the simultaneous (24-h) administration of CH, indicating that protein synthesis is required for the late ActD effect. Despite an overall 2-fold decrease in protein synthesis in cells treated with ActD at 24 h, the synthesis of individual proteins maximally induced by TSH during the first 8 h is increased, whereas that of some proteins maximally synthesized after 24-30 h is markedly reduced. The present data indicate that TSH-induced I- uptake in FRTL-5 cells involves a regulatory action of TSH that operates at the mRNA level.

Gentamicin penetration into diseased appendix tissue

Gentamicin concentrations in appendix tissue, serum, and peritoneal fluid were obtained in suspected cases of gangrenous or perforated appendicitis. Despite widely ranging gentamicin concentrations, no infectious complications developed. Correlations were made between the pathologic state of the tissue and the tissue gentamicin concentrations. Correlations were also made with tissue gentamicin concentrations and the time after the antibiotic dose to the time of sampling.

Cerebellar targets of visual pontine cells in the cat

The cerebellum receives visual mossy fiber input from the cerebral cortex via visual cells in the pons. We identified the regions of cat cerebellum that receive cerebral visual input by injecting orthograde tracers among physiologically identified visual pontine cells. Cerebellar labeling following these injections indicates that the contralateral paraflocculus and the rostral folium of the uvula (vermal lobule IX) receive the heaviest projection from cortically activated pontine visual cells. Lighter visual input reaches much of the rest of the contralateral posterior lobe. A second experiment combined, in the same animal, orthograde tracing of the visual corticopontine pathway with retrograde tracing of the pontocerebellar projection. The results of this experiment confirm that the paraflocculus and uvula receive more cortical visual input than do other regions of the cerebellum. This experiment also shows that uvula-projecting and paraflocculus-projecting cells occupy different parts of the ventromedial pons. Uvula-projecting cells cluster immediately adjacent to the ventral and medial borders of the pyramidal tract and near the midline. Paraflocculus-projecting cells lie ventral and medial to the pyramidal tract but displaced from its border. There are few paraflocculus-projecting cells near the midline.

Effect of body weight on gentamicin pharmacokinetics in neonates

The pharmacokinetics of gentamicin in large-for-gestational-age (LGA) and appropriate-for-gestational-age (AGA) newborn infants were compared in a prospective study. Serum gentamicin concentrations were drawn just before (trough) or after (peak) the third or fourth dose of gentamicin sulfate 2.5 mg/kg given as a 30-minute i.v. infusion every 12 hours to 11 LGA and 12 AGA infants. Peak (Cmax) and trough ( Cmin ) serum concentrations, elimination rate constants (k), volumes of distribution (V), and clearances (CL) were compared between the AGA and LGA groups and within the LGA group between obese (n = 6) and nonobese (n = 5) infants. The serum gentamicin concentrations achieved in the LGA infants were similar to those in the AGA infants, with Cmin values less than 2 micrograms/ml and Cmax values of 4-7 micrograms/ml. The mean pharmacokinetic variables determined were consistent with literature values reported for AGA infants. No significant differences in these variables were observed between the two groups or within the LGA group. Greater variability in Cmax, V, and CL was observed in the LGA group as a whole. The initial dose of gentamicin now recommended for AGA infants should be appropriate for LGA infants. However, serum concentrations should be monitored carefully to detect interindividual variability in pharmacokinetics so that adjustments can be made to ensure therapeutic serum concentrations.

Two-dimensional echocardiographic preoperative prediction of prosthetic aortic valve size

Aortic root diameter was measured by two-dimensional (2DE) and M-mode echocardiography in 20 adult patients (aged 29 to 69 years) undergoing aortic valve replacement in order to predict prosthetic aortic valve size. Eight patients had predominantly aortic stenosis, six had chronic aortic regurgitation, and six had acute severe aortic regurgitation secondary to infective endocarditis. 2DE measurements of aortic anulus diameter, as determined from the parasternal long-axis view, demonstrated a high correlation with actual prosthetic valve size implanted at surgery (r = 0.89, p less than 0.001, SEE 0.68 mm). 2DE exactly predicted actual prosthetic valve size in 12 of 20 patients (60%), was within 1 mm of prosthetic valve size in 6 of 20 patients (30%), and was within 2 mm of prosthetic valve size in two patients. In contrast, M-mode echocardiography failed to significantly predict aortic valve size (r = 0.14) because of its lack of two-dimensional anatomic orientation. Thus 2DE can safely and accurately predict preoperatively prosthetic aortic valve size and thereby be of great value in helping to avoid the problem of prosthesis-patient mismatch.

Hemodynamic monitoring of patients undergoing abdominal aortic surgery

Cardiac decompensation is clearly the major complication of aortic reconstructive surgery that leads to morbidity. Major changes in intravascular volume, third spacing, and increased systemic vascular resistance are extremely stressful to the diseased heart. Hemodynamic monitoring is readily available to provide an accurate evaluation of myocardial sensitivity and to allow for appropriate pharmacologic manipulation to preclude cardiac catastrophe. We believe all patients undergoing abdominal aortic reconstructive surgery should receive the benefit of pulmonary artery catheterization and intraarterial monitoring. The only requirement is a staff of surgeons, anesthesiologists, and nurses capable of correct interpretation of the data and use of drug therapy based on this information. The benefits are an accurate assessment of cardiac function with the ability to modulate the patient's hemodynamic values, preventing volume shifts, hypertensive and hypotensive crises, and abnormal fluctuations in preload and afterload, and ultimately a safer perioperative course.

Translocation of cytoplasmic estrogen receptors to the nucleus: immunohistochemical demonstration utilizing rabbit antibodies to estrogen receptors of mammary carcinomas

Rabbit antibodies to cytoplasmic estrogen receptors (ER) of human breast carcinoma were utilized for investigating steroid-triggered in-vitro translocation of cytoplasmic ER to the nuclear compartment of the estrogen target cells. The immunofluorescent method (IF) previously described (S Raam et al., Eur J Cancer Clin Oncol 18: 1-12, 1982) was employed for immunohistochemical localization of ER. Four cases of normal endometrium, two cancers of the endometrium, and MCF-7 human breast cancer cells were maintained in a steroid free medium and exposed at 37 degrees C for two hours to growth medium alone (control) or to 2.5, 25 or 250 nanomoles of estradiol (E2), diethylstilbestrol (DES), or monohydroxytamoxifen (OH-TX). At the end of the incubation period the cells were processed for intracellular localization of ER. Complete traslocation of IF from the cytoplasm to the nuclear compartment was evident in all normal endometrial cells exposed to E2, DES or OH-TX for two hours. While cells from the endometrial cancer 'S', like the normal cells, translocated IF to the nucleus, cells of another cancer ('KLE') failed to translocate when exposed to E2 or OH-TX. Partial translocation was evident in 'KLE' cells exposed to DES. In MCF-7 cells grown in the absence of E2, IF was exclusively cytoplasmic. When these cells were exposed to the hormones, 50% showed a complete transfer of IF to the nucleus; in 40% a delayed response was evident; 10% failed to translocate. The results revealed the suitability of anti-ER antibodies for investigating the intracellular dynamics of ER in target cells responding to estrogens or antiestrogens.

Multicomponent structure of the thyrotropin receptor: relationship to Graves' disease

The thyrotropin receptor is proposed to contain both a glycoprotein and a ganglioside component. Monoclonal antibodies have been developed against soluble thyroid TSH receptor preparations and using Graves' lymphocytes. These show that initial recognition of thyrotropin requires the glycoprotein component, but that monoclonal antibodies to this component block thyrotropin function (blocking antibodies) rather than mimic thyrotropin. Monoclonal antibodies which stimulate thyroid activity in cultured cell systems (cAMP increase) or mouse bioassays, all interact with gangliosides. Using monoclonal antibodies to the glycoprotein component of the thyrotropin receptor, we show that two protein bands, molecular weights 18,000-23,000 and 50,000-55,000, are precipitated from detergent-solubilized preparations. Using a crosslinking procedure with 125I-labeled thyrotropin, we show that thyrotropin binding is related to the disappearance of the 18,000-23,000 molecular weight band on sodium dodecylsulfate gels and the appearance of a 30,000-33,000 molecular weight thyrotropin-membrane component complex. Higher molecular weight thyrotropin-membrane complexes of 75,000-80,000 and 250,000 are visualized when binding studies are performed at pH 7.4 in physiologic medium; larger amounts of the 30,000-33,000 complex are evident at pH 6.0 in a low salt medium. It is thus proposed that the glycoprotein component of the thyrotropin receptor is composed of two subunits with apparent molecular weights of 18,000-23,000 and 50,000-55,000; that the 18,000-23,000 subunit interacts with thyrotropin; and that different receptor subunits can exist depending on in vitro binding conditions. Using monoclonal-stimulating antibodies or natural autoimmune IgG preparations from patients' sera, we show that stimulating antibodies exhibit species-specific binding to human thyroid ganglioside preparations. Individual components or determinants of the thyrotropin receptor structure with specific autoimmune immunoglobulins.

GC analysis of imidazopyrazole in plasma using nitrogen-specific detection

A sensitive, specific GC assay for imidazopyrazole in plasma was developed using nitrogen-specific detection. The samples are extracted with methylene chloride containing 7-bromo-imidazopyrazole as the internal standard and the extract derivatized with pentaflourobenzoyl chloride prior to isothermal chromatography on an OV-17 column. Peak-height ratio measurements produced linear standard curves over the concentration range of 0.045-40 microgram/ml. The practical limit of sensitivity was 50 ng/ml and typical between-run variability for replicate analysis of a control specimen produced a coefficient of variation of 5.1%. This method is applicable to the study of the pharmacokinetics of imidazopyrazole following therapeutic doses and was used to support such studies in parallel with Phase I clinical studies in children.

Aneurysmectomy in the octogenarian. A study of morbidity and quality of survival

The records of 52 octogenarians who underwent resection of an abdominal aortic aneurysm were reviewed. Thirty-five elective operations were performed with an operative mortality of 8.6 percent, which was twice that of the group less than 80 years of age. Seventeen emergency operations were performed for rupture with an operative mortality of 58.8 percent. Postoperative follow-up in the elective group found that by 6 months 93 percent of surviving patients had returned to their preoperative status. Survival rates by life table analysis were 67 percent at 1 year, 52 percent at 3 years, and 14 percent at 5 years. In the ruptured group, all patients at risk were alive at 1, 3, and 5 years. We advise elective resection of an abdominal aortic aneurysm in the octogenarian with good functional capacity using the same criteria that we use for younger patients. Most octogenarians can anticipate a prompt return to their usual environment and a meaningful postoperative life-style.