Glucocorticoids enhance glucose uptake and affect differentiation and beta-adrenergic responsiveness in muscle cell cultures

The role of glucocorticoids (GLC) in liver glycogen metabolism is well characterized; its role in peripheral tissues is not as well understood (Baxter, 1976). GLC administration in vivo is associated with hyperglycemia, but it is not clear whether decreased glucose uptake in a peripheral tissue like muscle accounts, in part, for the effect. We investigated the relationship of glucose uptake to beta-adrenergic responsiveness in muscle cell cultures exposed to GLC. Under these conditions GLC and other serum factors are present in at least a tenfold dilution relative to in vivo conditions. We observed that the GLC dexamethasone (DEX) induces a significantly enhanced Vmax for deoxyglucose uptake in the rat muscle cell lines L8 (200--400%) and L6E9 (50--100%). DEX inhibits cell fusion and promotes epithelioid morphology within the effective dose range (L8 greater than L6E9). Growth is slightly enhanced (10--20%) at 0.1--1.0 microM. In these cells DEX also inhibits intracellular beta-adrenergic-sensitive cyclic AMP accumulation and reduces basal, catecholamine-sensitive and fluoride-sensitive adenylate cyclase in cell homogenates. The effects of DEX on deoxyglucose uptake and beta-adrenergic responsiveness are both dose (1 nM--0.1 nM) and time (1--3 days) dependent, and reversible. The degree of inhibition of the beta-adrenergic system seems to be directly related to the degree of enhancement of deoxyglucose uptake. These observations suggest that the action of DEX on muscle cell glucose uptake is related to its effect on the beta-adrenergic system.

PR: a positive program, not professional rhetoric

A great deal of literature dealing with holistic medicine has been published in recent years. The proponents of holistic care seem concerned with treating the whole patient. Influencing factors such as environment, social background, individualism, etc. are all considered in establishing the patient's treatment. Traditional medicine appears to be more directly involved with the discovery and eradication of organic disease. It is proposed that one facet of the holistic concept be applied to our current system of health care delivery. A patient relations program takes manpower, time, money and a genuine interest in the patient. But the rewards far outweigh the costs. The patient, it is felt, is treated with greater understanding and concern. This elicits a positive comment from them to the attending technologist. The technologist is gratified that his efforts are noticed, and he continues to work at improving the professional services offered to a caring patient. It works! You can be justifiable proud of the radiology aides, secretaries, registered technologists and radiologists that continually strive to provide this personalized service to the "Whole Patient."

Inhalation exposure of cadmium workers: effects of respirator usage

The objective of this study was to determine the average reduction in inhalation exposures produced by intermittent use of filter cartridge respirators by cadmium workers. Inhalation exposure was estimated by measuring the cadmium concentration inside the respirator while it was worn or hanging around the worker's neck. Air concentrations of cadmium were measured simultaneously inside the respirator and at the worker's lapel with a dual sampling system. Each of nine workers were measured on three consecutive days for a full work shift. The average inhalation exposures ranged from 3 to 67 micrograms/m3 while the TWA lapel concentrations ranged from 19 to 3600 micrograms/m3; respirator use produced a substantial reduction in inhalation exposures when lapel concentrations were above 100 micrograms/m3. On the average, the inhalation exposure was 26% of the lapel concentration, but the effective protection varied widely between individuals and from day to day. If used cautiously, this relationship may be useful for estimating the approximate average inhalation exposure of a group of workers routinely using half mask respirators.

Chronic cadmium exposures associated with kidney function effects

A follow-up study was conducted on 27 workers with a median of 25 years exposure to airborne cadmium. Two exposure groups had been selected a low exposure group of office, laboratory and supervisory personnel (n = 11, average urinary cadmium 13.1 micrograms/l); and a high exposure group of production workers with long histories of work in areas with substantial airborne cadmium (n = 16, average urinary cadmium 45.7 micrograms/l). An estimate of each subject's time-weighted-average inhalation exposure to cadmium was calculated from personal sampling data (1973-1976) and area sampling data (1943-1976). Based on the findings of another study, the average inhalation exposures in each of the work areas were adjusted for use of personal protective masks (respirators). Comparison of kidney function status between the high and low exposure groups showed a significant reduction in creatinine clearance, and increased uric acid and beta microglobulin excretion by the high group. Significant renal effects were associated with estimated average inhalation exposures of 63 micrograms/m3 over a 25 year period. The relationship between urinary cadmium excretion and cumulative exposure changed for higher exposures; this was consistent with the "critical concentration" model of cadmium's effects on the kidney.

Effects of surgical stress and corticotrophin on the peripheral metabolism of thyroid hormones in rabbits

The effect of surgical stress and ACTH injection on the peripheral monodeiodination of thyroxine (T4) was studied in the rabbit. These stimuli resulted in a switch from the peripheral formation of tri-iodothyronine (T3) to reverse T3 in normal rabbits and in rabbits whose thyroidal secretion was suppressed by administration of T4. This is analogous to the situation in man. These changes were not due to alterations in the serum binding capacity for thyroid hormones.

The role of sodium transport in thyroid thermogenesis

The hypothesis that augmentation of Na+ transport activity mediates a significant fraction of thyroid thermogenesis is supported by studies on a wide range of target tissues. Recent criticisms based on theoretical and experimental considerations do not appear to negate the validity of this concept. A basic difficulty that remains to be resolved, however, is the development of techniques for assessing the contribution of the Na+ transport pathway to energy turnover in the intact animal.

Pulmonary function in firefighters: acute changes in ventilatory capacity and their correlates

A group of 39 firefighters was examined during routine firefighing duty. Following smoke exposure the average decrease in one-second forced expiratory volume (FEV1.0) was 0.05 litre (137 observations). This decline in FEV1.0 was related to the severity of smoke exposure as estimated by the firefighter and to the measured particulate concentration of the smoke to which he was exposed. Decreases in FEV1.0 in excess of 0.10 litre were recorded in 30% of observations. Changes in FEV1.0 resulting from a second exposure to smoke on the same tour of duty were greater when smoke exposure at the previous fire was heavy. The repeated episodes of irritation of the bronchial tree that have been documented in this investigation may explain the origin of the previously observed chronic effect of firefighting on respiratory symptoms and pulmonary function.

Carcinoma of the hypopharynx--a five year follow-up

This is a study of 339 patients with carcinoma of the hypopharynx, seen in Toronto from 1960-72. Patients were grouped according to the U.I.C.C., T.M.N. classification but a modified staging method was employed since there is no generally accepted procedure for stage-grouping at the present time. Patients treated by primary radiation were compared to a group treated by combined therapy (radiation followed by surgery). The results show that the overall crude survival of all hypopharyngeal lesions was approximately 20 per cent. A high percentage of patients had advanced lesions at first presentation and almost 30 per cent of patients were treated palliatively. Analysis indicated that combined therapy is the treatment choice for Stage I and II hypopharyngeal lesions. Patients with more advanced lesions do poorly regardless of the treatment modality. The morbidity and mortality rates are high in the combined therapy group but the risks were doubled when salvage surgery was undertaken for failed primary radiotherapy.

Airborne arsenic exposure and excretion of methylated arsenic compounds

First void urine samples were collected from copper smelter workers exposed to inorganic arsenic and from unexposed controls. Arsenic compounds (As (III), As (V), methylarsonic acid and dimethylarsinic acid) in these samples were analyzed by selective volatilization as arsines with determination of arsenic by plasma excitation emission spectrometry. On the day preceding the urine sample collection a breathing zone measurement was made of respirable arsenic particulates for each subject. It was found that all of the subjects, including the controls excreted arsenic primarily as methylated species. Approximately 50% of the total arsenic was excreted as dimethylarsinic acid and 20% as methylarsonic acid. Slight differences in the proportion of various arsenic compounds were observed with varying levels of inorganic arsenic exposure. Amounts of arsenic species were all closely correlated with each other and with exposure. Irrespirable particulate exposures were measured on a subset of high exposure workers. Irrespirable arsenic was found to be more closely correlated with excretion of arsenic compounds than was respirable arsenic.

Mycoplasma pneumonia: a study on hospitalized American patients with pneumonia in Vietnam

A prospective study on consecutively hospitalized pneumonia patients showed that 41.5% of 58 patients had a fourfold rise in the complement-fixation titer for Mycoplasma pneumoniae. Viral isolation techniques and serologic tests for influenza A1, A2 and B, parainfluenza 1 and 3, respiratory syncytial virus and the adeno virus group yielded only a single positive isolate for influenza A2. Serologic tests for melioidosis, leptospirosis, scrub, murine and epidemic typhus and psittacosis were all negative. The clinical manifestations were not distinctive for the positive M. pneumoniae patients when compared with the patients having a negative M. pneumoniae complement-fixation test. The symptoms and signs and laboratory and radiologic findings were similar to those described in other reports on primary atypical pneumonia.

Pulmonary impairment from chronic exposure to sulfur dioxide in a smelter

The pulmonary function of 113 copper smelter workers was measured in 1973 and again in 1974 to asses the effects of chronic exposure to sulfur dioxide. Respiratory symptoms, smoking history, occupational history, and pulmonary function as measured by forced vital capacity and 1-sec forced expiratory volume were recorded. Exposures to sulfur dioxide, respirable particulates, sulfates, and copper were sampled at intervals throughout the year by personal monitoring. Exposure to 1.0 to 2.5 ppm of sulfur dioxide was associated with excessive loss of 1-sec forced expiratory volume during the year and an increase in respiratory symptoms, after controlling for smoking. No significant interaction between sulfur dioxide and concurrent exposure to respirable particulates on pulmonary function was found. Workers with 1-sec forced expiratory volume below normal on initial measurements (based on their age and height) showed evidence of even greater losses of pulmonary function related to sulfur dioxide exposure.

Measurement of protection factors of chemical cartridge, half-mask respirators under working conditions in a copper smelter

The performance of three commonly used chemical cartridge respirators for SO2 was measured under working conditions in a copper smelter. An effective SO2 protection factor for each man-respirator trial was calculated as the ratio between average SO2 concentrations sampled outside the respirator mask and that simultaneously sampled from inside the mask. The in-use SO2 protection afforded by the three respirators proved to be highly variable with mean protection factors of 22, 18, and 13. The distributions of the protection factors and the effects of mask type, facial size, and mask comfort are discussed.

Pulmonary effects of chronic exposure to airborne cadmium

Workers chronically exposed to high concentrations of airborne cadmium showed a significantly decreased forced vital capacity relative to a low-exposure group and had Po2 values in the normal range, but at the extreme low end. They had no significant decrease in 1-sec forced expiratory volume or maximal mid-expiratory flow. Chest roentgenograms showed mild or moderate interstitial fibrosis in 29 per cent of the group exposed to cadmium. Collectively, these results suggest a mild fibrotic reaction associated with exposure to cadmium. A dose-response association was observed between forced vital capacity, expressed as per cent predicted, and both average urinary cadmium concentration (P less than 0.003; r=-0.53) and maximal urinary cadmium concentration (P less than 0.005; r=-0.51). Further, a dose-response relationship was found between the forced vital capacity and months of work in cadmium fume areas, but not for months of exposure to cadmium sulfate aerosol.

The effects of ascorbic acid on diphtheria toxin and intoxicated HeLa cells

Ascorbic acid (vitamin C) prevented diphtheria toxin from inhibiting the incorporation of [U-14C]-alanine into trichloroacetic acid precipitable material in HeLa cells. Ascorbic acid did not exhibit an effect on the adenosine diphosphate-ribosylation of amino acyl transferase II nor did it separate fragment A from fragment B in "nicked" toxin. A non-specific reducing agent, para-methylaminophenol sulfate, exhibited an effect on HeLa cells very similar to the results of ascorbic acid. Citric acid, a tricarboxylic acid, had no effect on HeLa cells.

Cadmium, lead, and copper blood levels in normal children

Cadmium, lead, and copper levels were measured in duplicate whole blood samples from 60 apparently normal children, ranging in age from 2 months to 13 years, who were hospitalized for elective surgery. Metals were measured by atomic absorption spectroscopy after the samples were chemically oxidized and digested. Cadmium was concentrated by dithizone extraction before analysis. Blood cadmium averaged 0.66 mug/100 gm, with a standard deviation of 0.25. No samples had cadmium concentrations less than could be detectable. The average concentration of lead was 15.7 mug/100 gm with a standard deviation of 6.33. Copper averaged 123 mug/100 gm with a standard deviation of 35.5. Tolerance intervals were calculated for each metal in order to estimate the bounds of whole blood metal values in normal children. The intervals containing 95% of normal values with a probability of .95 were 0.22-1.70 mug Cd/100 gm, 0.87-30.5 mug Pb/100 gm, and 40.0-206 mug Cu/100 gm.

Respirator compensation of a portable air monitor

A respirator-compensated, portable air-monitor has been devised by modifying a commercially available personal air sampling pump. A switching circuit box, integrated into the sampling pump electrical system and activated by a micro switch mounted within the respirator mask, turns the pump off and a timer on whenever the respirator is worn. Thus, valid measurements of an individual worker's environmental exposures can be made even though that worker uses a respirator at his own discretion.