Step test predictions of maximum oxygen uptake before and after an employee fitness programme

The Canadian Home Fitness Test has been administered to two large office populations on three occasions over a 9 month period. At the control company (87M, 89F), there was some improvement of test scores from the initial to the final visit (decrease of heart rate in 6th minute of exercise 5.7 beats X min-1 in men, 9.5 beats X min-1 in women); this may reflect habituation to the test procedure. At the experimental company (180M, 258F), employees were given the opportunity of participation in an Employee Fitness Programme. High adherents to this programme (61M, 97F) showed a substantial decrease of 6 min exercise heart rate (12.8, 16.0 beats X min-1) with an increase of CHFT duration (2.59, 2.33 min) and VO2max (Jetté prediction, 3.8, 2.9 ml X kg-1 min-1). These changes were much larger than in either the control group, or in "non-participants" (54M, 46F) and "drop-outs" (19M, 48F) in the experimental company. Low adherents to the fitness programme (46M, 67F) occupied an intermediate position. Given accurate pulse counting, about a sixth of the high adherents would have detected no change of CHFT score if a single test was carried out after completing 6 months in the fitness programme; however, in some of these subjects there may indeed have been no training response. Because it gives a low weighting to exercise heart rate, the Jetté equation indicates a smaller effect of training than the Astrand nomogram.

Dose-dependent disposition of n-hexane in F-344 rats after inhalation exposure

The purpose of this study was to assess the disposition of radioactivity in rats after single inhalation exposures to varying concentrations of [1,2-14C]-n-hexane. Male Fischer 344 rats were exposed to 500, 1000, 3000 or 10,000 ppm 14C-n-hexane for 6 hr and the elimination of radioactivity followed for 72 hr after exposure. The disposition of radioactivity was dose-dependent, with 12, 24, 38 and 62% of the acquired body burden excreted as n-hexane by the lung with increasing exposure concentration. In contrast, 38, 31, 27 and 18% of the body burden of radioactivity was recovered as expired 14CO2 and 35, 40, 31 and 18% was recovered in the urine with increasing n-hexane concentration. Radioactivity remaining in the tissues and carcass 72 hr after exposure represented 6.1, 8.8, 7.4 and 5.4% of the body burden for the respective exposures. The dose-dependent elimination of radioactivity was apparently due in part to an inhibition of n-hexane metabolism, reflected by a decrease in total 14CO2 and urinary 14C excretion after 10,000 ppm exposure compared to the 3000 ppm exposure.

Lithium and the kidney: a review

The effects of lithium on renal water and electrolyte transport have generally been considered to be reversible following the cessation of lithium treatment. However, several recent reports have suggested that lithium-induced nephrogenic diabetes insipidus may persist for months or even years after lithium is discontinued. In addition, a number of reports have described the development of renal insufficiency (in association with interstitial nephritis) in some patients who have been chronically treated with lithium. The authors briefly review the effects of lithium on renal tubular transport and critically examine the reports of lithium-induced renal disease.

'I took a life because I needed one': psychotherapeutic possibilities with the schizophrenic offender-patient

This paper's fulcrum is a schizophrenic's explanation as to why he had taken a life: 'I took a life because I needed one.' It attempts to describe the exploration of therapeutic possibilities with the schizophrenic offender-patient. Particular attention is paid to the Associative Mode. This is a way of safely engaging with the patient in the depth of his experience without shattering his precarious defences. The discussion illustrates the close inter-dependence between the dynamic content of individual and group psychotherapy, the life of the hospital as a whole and the significance of therapeutic space being contained within a secure perimeter.

Proprioception in schizophrenia

B. Ritzler (J. Abnorm. Psychol., 86: 501-504, 1977) failed to replicate previous weight-lifting studies showing a proprioceptive deficit in schizophrenics. However, Ritzler did not use the same standard weights that the previous studies employed. Could this difference in procedure have caused his failure to replicate? Two experiments were completed to provide additional information about this question and related issues. In Experiment I, chronic hospitalized schizophrenics and normals were tested with light and heavy weights. Rosenbaum's original modified method of limits and the method of constant stimuli were utilized. Both methods provided comparable results, which, like Ritzler's data, failed to show a differential impairment in the discrimination of the light weights for paranoid schizophrenics. In Experiment II, outpatient paranoid schizophrenics, outpatient nonparanoid schizophrenics, outpatient psychiatric patients, and aged normals were evaluated utilizing the same psychophysical procedure and standard weights employed in the original studies. No differential impairment was found for the light weights for any group. These results provide strong support for Ritzler's position that a proprioceptive deficit is not unique to schizophrenia.

Aldosterone-induced proteins in toad urinary bladders. Identification and characterization using two-dimensional polyacrylamide gel electrophoresis

Aldosterone-stimulated Na+ transport is mediated by new protein synthesis, but the identification of specific aldosterone-induced proteins (AIPs) has proven difficult and the cellular function of such proteins is unknown. Using high resolution two-dimensional polyacrylamide gel electrophoresis and autoradiography we have identified AIPs of similar isoelectric points (5.8 to 6.4) and molecular weights (70,000 to 80,000) in membrane-rich and cytosolic subcellular fractions of epithelial cells derived from single toad urinary bladders. The ability of actinomycin D to inhibit both AIP synthesis and aldosterone-induced Na+ transport is consistent with a role for these proteins in the natriferic action of aldosterone. In addition, since non-natriferic concentrations of cortisol did not induce similar proteins, AIP synthesis appears to be mineralocorticoid-specific. The relationship of AIP synthesis to Na+ transport was also studied. Since amiloride, which blocks Na+ transport in high resistance epithelia, did not affect the synthesis of these proteins, Na+ transport is not required for their synthesis. In addition, similar proteins were not induced when Na+ transport was stimulated by antidiuretic hormone and theophylline. Consequently, AIP synthesis is not merely a nonspecific consequence of the cellular metabolic changes associated with Na+ transport.

Internal potassium balance and the control of the plasma potassium concentration

The plasma potassium concentration is determined both by external potassium balance and by the distribution of potassium between extracellular and intracellular fluid compartments, i.e., "internal potassium balance." Whenever external potassium balance is altered, the resultant change in the plasma potassium concentration is strongly influenced by concomitant alterations in internal potassium balance. Several factors alter internal potassium balance independently of changes in external balance. Acid-base disturbances produce shifts of potassium into or out of cells, but attempts to quantify these effects are not likely to be clinically useful. Hypertonicity produces a shift of potassium out of cells. Several hormones (insulin, aldosterone, catecholamines, glucagon, and growth hormone) may have roles in internal potassium balance. Digitalis and succinylcholine, by producing efflux of potassium from cells, may cause hyperkalemia. Potassium is released from skeletal muscle during exercise, causing an increase in the plasma potassium concentration. The periodic paralyses are associated with well-defined transient alterations in internal potassium balance.

Fitness program participation: its effect on worker performance

The effects of an employee fitness program upon absenteeism and productivity were investigated in a controlled trial involving two large offices. During the six-month experimental program, the test company developed substantial gains of fitness. However self-reports and supervisor evaluations showed small and relatively similar gains of productivity, with reduction of absenteeism at both test and control companies. Further studies on a large scale are warranted. The presently observed changes probably reflect (1) sample attenuation, (2) seasonal trends, and (3) a "Hawthorne" effect. If the last factor is substantiated, employee fitness programs may be of economic interest, despite the nonspecific nature of the resultant gains in productivity.

Subcellular localization of aldosterone-induced proteins in toad urinary bladders

Paired toad urinary hemibladders were incubated with [35S]methionine in the presence (experimental) or absence (control) of aldosterone. Short-circuit current was used to monitor aldosterone-induced Na+ transport. Protein synthesis in epithelial cell subcellular fractions (cytosolic, microsomal, mitochondrial) was evaluated by gradient polyacrylamide gel electrophoresis and autoradiography. Aldosterone-induced proteins were identified in the cytosolic and microsomal fractions (70 000 and 15 000 daltons, respectively). These results represent the first demonstration of aldosterone-induced proteins in subcellular fractions of epithelial cells derived from single toad urinary hemibladders.

Ultrastructural studies of a polygonal myofilament network in cultured rat aortic smooth muscle cells

Cultured rat aortic smooth muscle cells (SMC) were examined by electron microscopy and found to contain polygonal networks of 75 A degrees thin myofilament bundles. The cells also had large bundles of longitudinally aligned thin myofilaments with periodically spaced dense bodies. Abundant plasmalemmal vesicles were present at the cell periphery, and the cells were connected by desmosomes. Intercellular spaces contained sparse amounts of elastic fibers, a material generally present in SMC cultures. Analyses of amino acids by automated column-chromatography showed that isodesmosine and desmosine, two amino acid residues unique for elastin, were present. Accordingly, it was concluded that polygonal networks, previously detected solely in cultured nonmuscle cells, were present in SMC. Other findings suggest 1) a change in myofilament arrangement takes place during cell migration, and 2) rat aortic SMC grown in tissue culture flasks is an important experimental tool in the study of cell motility since such myofilament rearrangements were observed to occur up to fourteen days in first passage.

Post-coronary rehabilitation and risk factors, with special reference to diet

Volunteers were randomly allocated to high intensity exercise (HIE, n = 17, added energy expenditure, 254 progressing to 761 kJ . day-1) and light intensity exercise (LIE, n = 13, < 76 kJ . day-1) programs for a period of one year, commencing 3-12 months after myocardial infarction. Dietary behaviour (7-day records), activity levels (diary records of prescribed activity) and body composition (skinfold readings) were noted at the beginning and end of the study. Both subject groups initially had a low level of energy expenditure (approximately 9.4 MJ . day-1) and a diet relatively low in animal fat. The HIE group showed no significant changes of energy intake, body composition, or blood lipids over the year of observation. In contrast, the LIE group reported a decrease in both energy intake (1.45 MJ . day-1, P < 0.05) and the intake of most individual dietary constituents. It also showed a decrease of triglyceride (P < 0.05), but a suggestion of an increase of subcutaneous fat (triceps, P < 0.05). The HIE program does not confer any necessary advantage of body composition or serum lipid levels, but it does allow a larger food intake. It may thus be of particular value for patients who find adherence to low energy or low cholesterol diets irksome.

Some characteristics of participants in an industrial fitness programme

A controlled study has allowed an investigation of several hypotheses relating to initial recruitment and continued participation in an employee fitness programme. Following initial physiological and psychological testing, attendance records show that the staff of the experimental company sorted themselves into four categories (non-participants, drop-outs, low adherents, and high adherents). Parallel observations were made at a second, comparable company where there was no employee fitness programme. Exercise classes met three times per week for 30 minutes of rhythmic calisthenics and endurance-type activities. Continued participation was favoured by a short stature, but perhaps because of gentle progression of intensity, there was no selective loss of obese subjects. A below average strength in high adherent men was related to their short stature. Participation was favoured by an interest in activity as the release of tension on the scale of Kenyon (women). Negative factors were a low score for personal and social factors on the scale of Holmes & Rahe (men), a recent health change (women), dissatisfaction with pay on the Job Description Index of Smith et al. (male non-participants, female drop-outs), and an interest in activity as Games of Chance (women). In the men, "Type A" score on the questionnaire of Friedman and Rosenman was highest in those with infrequent participation, but not in drop-outs; this possibly reflects a real time conflict among upper executives. Body image (Kenyon and McPherson scales), manifest anxiety (Taylor Scale) and reported health (Cornell Medical Index) were unrelated to participation in the programme. Lessons for future programming include (i) matching of prescribed activity to body build, (ii) gentle progression (to avoid discouragement of the obese), (iii) attention to the desired rewards of the individual, and (iv) flexibility of class schedules to accommodate subjects with real or perceived time conflicts.

Some factors influencing serum lipid levels in a working population

Life-style variables (perceived fitness, excess body mass, percent fat, lean mass, predicted maximum oxygen intake, cigarette consumption, alcohol consumption, use of contraceptive medication) have been related to the lipid profile (serum triglycerides, total cholesterol, HDL and LDL cholesterol) in a sizeable volunteer population of Toronto office-workers. Multivariate analysis demonstrates an independent positive association of age with total cholesterol, HDL and LDL cholesterol, and (in women only) a weak negative association with triglycerides. Much of the fitness effect is related to body fat, which is positively correlated with triglycerides and (in the men only) with total and LDL cholesterol, but is negatively related to HDL cholesterol. However, maximum oxygen intake per unit of body mass shows a small independent association with triglycerides, total cholesterol (women only) and LDL cholesterol. Cigarette smoking bears an independent relationship to triglycerides, HDL cholesterol and (in women only) LDL cholesterol. Alcohol consumption is independently related to high values for total and LDL cholesterol, but is also related to high HDL cholesterol readings. While multivariate analysis allows for the inter-relationship of smoking habits, alcohol consumption, and the various fitness measurements, it cannot prove cause and effect. Nevertheless, the potential improvement of lipid profile associated with (i) abstinence from cigarettes, (ii) a 4% reduction of body fat, and (iii) avoidance of contraceptive medication is sufficient to warrant experimental trial of such a change in life-style.

Effects of a 6-month industrial fitness programme on serum lipid concentrations

The serum lipid profile (total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides) has been studied in 98 men and 158 women before and 6 months after introducing an employee fitness programme. Over this period, the sample sorted itself into 4 sub-groups (non-participants, drop-outs, high adherents, and low adherents). The high-adherents attended 2--3 30-min physical activity classes per week over the 6-month study, progressing to 15--17 min of aerobic activity per session, with significant gains of predicted maximum oxygen intake, and reductions of body fat. Nevertheless, there were few "favourable" changes of lipids that could be related to the physical activity sessions. A decrease of total cholesterol (mainly in the women) was unrelated to the changes of maximum oxygen intake, and occurred equally in non-participants and high adherents. High adherent women showed a decrease of LDL cholesterol, but this also was almost matched by changes in non-participants, while the main response of HDL cholesterol was a decrease in non-participants and drop-outs rather than an increase in high-adherents. It is concluded that if data are collected while subjects are in energy balance and persisting with their activity, a programme of the intensity practical in an employee fitness class has little impact upon blood lipids.

Physical fitness, respiratory symptoms and lung function

Lung volumes (FVC1, FEV1.0 and peak flow) were measured in 403 men and 561 women volunteers for fitness testing, using the SRL automated spirometer system. Average scores for this population were 5--10% higher than predicted from age, height and sex using either the formulae inherent in the SRL computer or standards proposed by Anderson et al. [1968] for the Toronto population; existing standards may thus underestimate respiratory potential. Lung function data showed a dose-dependent decrease within the category of cigarette smokers, but there was no significant difference between average results for smokers and non-smokers. Multivariate analysis showed significant contributions of lean mass and obesity to the overall description of lung volumes; however, effects were not large enough to justify incorporation of such variables into routine prediction equations. Positive responses to the respiratory section of the Cornell Medical Index were in several instances associated with below expected lung volumes. The most consistent response was to the question 'do you suffer from asthma?' Although the average effect was significant, the magnitude of response (10--20%) would have been overlooked in individual testing; this suggests that there may be more scope for pulmonary screening through the improvement of questionnaires than through the purchase of expensive electronic spirometers.

Some factors affecting accuracy of Canadian Home Fitness Test scores

Factors affecting the accuracy of Canadian Home Fitness Test scores have been evaluated in male and female office workers. At a first attempt, the typical subject underestimates his 10 sec post-exercise pulse count by 1 beat, with a superimposed probable error of 2 beats. However, the modest experience of pulse counting gained in an employee fitness programme corrects the systematic error, while the probable random error is reduced to approximately 8 beats/min. Taking account also of variations in the fficiency of stepping, the probable error of an Astrand prediction of V O2(max) is approximately 10.3%. Comparison with directly measured values in a subsample of 22 men shows an actual random discrepancy of 9.5%, plus a systematic error of approximately 19% due to an increase of heart rate with anticipation of the maximum test. The Jetté prediction formula has a random discrepancy of approximately 8%, plus a systematic error of approximately 10.6%. Assuming the latter can be corrected by evaluation of a larger population, the fitness scores should give most people an indication of both their initial fitness and responses to a training regimen.

Effects of tetracyclines on aldosterone- and insulin-mediated Na+ transport in the toad urinary bladder

The effect of oxytetracycline and demethylchlortetracycline on aldosterone- and insulin-mediated Na+ transport (short-circuit current) were examined in toad urinary bladders mounted in modified Ussing chambers. Oxytetracycline had little or no effect on either basal or aldosterone-mediated Na+ transport. In contrast, demethylchlortetracycline markedly inhibited both basal and aldosterone-mediated Na+ transport. Furthermore, demethylchlortetracycline inhibited the aldosterone response significantly out of proportion to its effects on basal Na+ transport. Neither of the drugs had an effect on insulin-mediated Na+ transport. Consequently, the natriuresis observed in certain patients treated with demethylchlortetracyline may be related to drug-induced renal resistance to the effects of aldosterone.

Tetracycline-induced inhibition of Na+ transport in the toad urinary bladder

The effects of three tetracyclines, demethylchlortetracycline (DMC), minocycline (MNC), and oxytetracycline (OTC), on Na+ transport (measured as short-circuit current) were examined in toad urinary bladders mounted in modified Ussing chambers. During a 1-h incubation period serosal DMC (but not MNC or OTC) inhibited basal Na+ transport, whereas MNC (but not DMC or OTC) inhibited ADH-stimulated Na+ transport. MNC also inhibited cyclic AMP-stimulated Na+ transport. During longer incubation periods all three drugs inhibited basal Na+ transport. The DMC-induced inhibition of basal Na+ transport and the MNC-induced inhibition of ADH-stimulated Na+ transport were paralleled by an inhibition of the active conductance of the bladders. Thus, although all three drugs inhibit basal Na+ transport, only MNC inhibits ADH-stimulated Na+ transport. This effect does not correlate with the known effects of the tetracyclines on ADH-stimulated water flow or with drug-protein binding, and may be related to the greater lipid solubility of MNC.

Detection of barbiturates by latex agglutination inhibition

A latex-agglutination inhibition test was developed and evaluated for the detection of barbiturates, primarily in urine, but it has applicability to serum. The 2-h test was performed with samples free of gross debris in a 37 degree C heat block and the reaction between the barbiturate antibody and the barbiturate-latex, at pH 7.3, was inhibited by urines containing secobarbital, amobarbital, pentobarbital, butabarbital, or phenobarbital. For laboratory standards the test was particularly sensitive to secobarbital (300 microgram/litre) and relatively insensitive to amobarbital (5000 microgram/litre). In clinical specimens some barbiturates were detected at levels as low as 150 microgram/litre. The test was specific, and negative endpoints were frequently noted in as little as 30 min. The effects of variables (antiserum dilution, urine specific gravity, heat block temperature, sample size, and type of barbiturate) on the degree of agglutination were also determined.

Superiority of demeclocycline over lithium in the treatment of chronic syndrome of inappropriate secretion of antidiuretic hormone

We evaluated demeclocycline and lithium therapy in 10 patients with the syndrome of inappropriate secretion of antidiuretic hormone. Despite severe water restriction, all patients had hyponatremia (mean +/- S.E.M. serum sodium of 122 +/- 1.1 meq per liter) and elevated urine osmolality (744 +/- 59 mOsm per kilogram) before treatment. Demeclocycline (600 to 1200 mg daily) restored serum sodium concentration to 139 +/- 1.1 meq per liter within five to 14 days, permitting unrestricted water intake in all patients. In three patients given lithium carbonate (900 mg daily) the serum sodium concentration, urine osmolality and urine volume were unchanged; since two patients had adverse central-nervous-system symptoms during lithium therapy, further study of this agent was abandoned. A patient with an unusual 22-year history of the syndrome was unresponsive to lithium, whereas long-term treatment with demeclocyline was markedly effective. Demeclocycline is superior to lithium in the treatment of the syndrome and may obviate the need for severe water restriction.

Impaired renal tubular potassium secretion in systemic lupus erythematosus

Two patients with long-standing systemic lupus erythematosus were found to have persistent hyperkalemia. The hyperkalemia could not be explained by renal insufficiency, oliguria, diminished distal sodium delivery, acidemia, or hemolysis. After sodium depletion, urinary aldosterone excretion and plasma aldosterone concentration rose appropriately. No increase in urinary potassium excretion or decrease in serum potassium concentration was noted after fludrocortisone acetate, furosemide, or acetazolamide plus sodium bicarbonate. We conclude that these patients have a primary defect in renal tubular potassium secretion that may be related to an immune complex interstitial nephritis.

Insulin-mediated Na+ transport in the toad urinary bladder

The characteristics of insulin-induced Na+ transport in the toad urinary bladder were determined and compared to those of aldosterone. Bladders were mounted in modified Ussing chambers, and standard short-circuit current techniques were employed to measure transepithelial Na+ transport. Insulin added to the serosal medium is much more effective than insulin added to the mucosal medium. Serosal insulin concentrations from 10(1) to 10(3) muU/ml increase both the initial rate and the final level of Na+ transport achieved, whereas concentrations from 10(3) to 10(5) muU/ml increase only the initial rate of Na+ transport. Insulin-induced Na+ transport probably does not require glucose. Both insulin- and aldosterone-induced Na+ transport are directly proportional to serosal (but not mucosal) K+ concentration over the physiologic range (2.0-7.0 meq/liter). However, cycloheximide abolishes aldosterone- but not insulin-induced Na+ transport. In addition, insulin stimulates Na+ transport after a maximal response to aldosterone, and aldosterone stimulates Na+ transport after a maximal response to insulin. Thus, although they have several similar characteristics, insulin and aldosterone have at least partially independent mechanisms of action on Na+ transport in the toad urinary bladder.

Acute hyperkalemia induced by hyperglycemia: hormonal mechanisms

Two insulin-requiring diabetics with isolated hyporeninemic hypoaldosteronism cpontaneously developed hyperkalemia that was aggravated whenever blood glucose concentration rose. Acute glucose infusions raised the serum potassium concentration in these patients with combined insulin and aldosterone deficiency but lowered, or did not change, the serum potassium concentration in normal subjects and in patients with either aldosterone or insulin deficiency alone. The paradoxical hyperkalemic response to glucose in patients with combined hormonal deficiency was blunted by prior administration of desoxycorticosterone acetate and abolished by prior administration of insulin. Our studies emphasize the crucial roles played by insulin and aldosterone in regulating the serum potassium concentration in man, and the need to avoid hyperglycemia in patients with combined insulin and aldosterone deficiency.

Psychotherapy and sociology: flirtation, marriage or divorce?

Psychotherapy and sociology are themselves products of mixed marriages; each experiences problems of identity and their children face problems of legitimacy. This paper considers the relevance of some sociological perspectives to the psychotherapeutic process, using the following analogies; (1) Flirtation: Why the attraction? 'going steady' or 'femme fatale'? (2) Marriage: Mutual enrichment, cross-fertilisation and new life? Examples of shared perspectives in the work of E. Becker, Erikson, Goffman etc. Influence of psychosocial contexts on psychotherapeutic processes. (3) Divorce: Too little shared life or too much destructive criticism? If the world within man and the world between men are interrelated, psychotherapy and sociology--although at times uneasy bedfellows--have much to give each other.