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Biomedical subjects

P O Wester

Publications and source records attributed to P O Wester.

At least 73 records · Page 4Linked to original sources
PubMed1986

Distribution of cadmium, lead and zinc in lung, liver and kidney in long-term exposed smelter workers.

Increased mortality due to various malignancies is reported from long-term exposed, non-ferrous smelter workers. In the present study the post-mortem distribution of cadmium, lead and zinc in lung, liver and kidney is reported and related to exposure and mortality. The study involved 86 male copper smelter workers who died after April 1975. Lung samples were taken from all workers and liver and kidney samples were taken from about one-quarter of the workers. Two control groups were used. The exposed workers were divided into six groups based upon diagnoses in medical records and autopsy protocols. Lead and zinc were analyzed by atomic absorption spectrophotometry and cadmium by neutron activation analysis. For the skewly distributed tissue levels, non-parametric statistical processing was used. Of the workers, 53% died from cardiovascular diseases and 30% from malignancies (8% from lung cancer). Cardiovascular diseases predominated in the two control groups: about 75 and 100%, respectively. Lung and liver cadmium concentrations were significantly higher in the lung cancer group of smelter workers than in the other groups of smelter workers (p less than 0.05) and rural controls (p less than 0.01). Cadmium in kidney, and lead in lung and liver were significantly higher (p less than 0.03) in the lung cancer group than in rural controls, but did not differ from that of the other workers. Zinc in lung, liver and kidney did not differ between exposed workers and controls. Rather strong Spearman rank-order correlation coefficients were found between the cadmium content of lung, liver and kidney tissue, especially in non-smoking smelter workers and rural controls. Smoking was more common in the lung cancer group than in the total group of smelter workers. Cadmium levels in the lungs of exposed workers were significantly higher (p less than 0.001) in smokers than in both ex-smokers and non-smokers. Earlier studies of the same workers gave significantly lower selenium levels in lung tissue compared with other groups of smelter workers and controls. As other carcinogenic substances are present in the working environment, e.g. arsenic, chromium and benzo [alpha]-pyrene, the specific effect of cadmium in the development of lung cancer cannot be evaluated at present.

Animals↗
PubMed1986

Serum thyroid-stimulating hormone in cerebrovascular disease.

A thyrotropin-releasing hormone (TRH) test with serum thyroid-stimulating hormone (TSH) assays was performed in 22 euthyroid stroke patients without thyroid disease and the results were compared with those in 17 age-matched euthyroid controls. Basal and maximum TSH levels after TRH injection were significantly lower in the stroke group without elevation of basal serum thyroid hormone levels. There was a tendency towards an inverse relationship between TSH levels and the degree of pareses of the extremities. The test was repeated in 7 stroke patients 3-4 months after the onset of stroke with essentially the same results. The abnormal TSH parameters in stroke patients seem to be the result of the brain lesion per se.

Aged↗
PubMed1986

Salt and water balance in congestive heart failure.

The majority of symptoms related to congestive heart failure (CHF) can be derived from the excessive accumulation of fluid in the body. The retention of fluid is the result of the activation of a complex system of compensatory mechanisms working on the kidneys and altering the hemodynamic situation in the body. The compensatory mechanisms are essentially the same as those activated in acute blood loss. The common denominator for CHF and acute blood loss is a decrease of the effective arterial blood volume (EABV), a parameter defined as blood volume in relation to vascular capacity. In the early stages of CHF there is an increased sympathoadrenergic tone, leading to a peripheral vasoconstriction and a decrease of blood flow to the kidneys. Due to a preferential constriction of the efferent arterioles, the filtration fraction is increased and the glomerular filtration rate remains unchanged. However, there is an increased colloid osmotic pressure and a decreased intravascular hydrostatic pressure in the peritubular capillaries. These alterations result in an increased reabsorption of sodium and water in the kidneys. Furthermore, the blood flow in the kidneys is rerouted from the cortical to the juxtamedullary nephrons, which have larger glomeruli and longer loops of Henle. This will further increase the retention of salt and water. The renin-angiotensin-aldosterone (R-A-A) system is also activated due to the decrease of EABV. Angiotensin II exerts about the same effects as norepinephrine--vasoconstriction, rerouting of blood within the kidney and preferential vasoconstriction of the efferent arterioles--all changes contributing to the retention of salt and water.(ABSTRACT TRUNCATED AT 250 WORDS)

Arginine Vasopressin↗
PubMed1986

Intracellular electrolytes in cardiac failure.

In congestive heart failure (CHF) there are several compensatory mechanisms operating which may influence electrolyte metabolism. The activation of the renin-angiotensin-aldosterone system causes retention of sodium (Na) and losses of potassium (K) and magnesium (Mg). The secondary hyperaldosteronism may give rise to high intracellular Na and low intracellular K through a direct permeability effect on the cell membrane. The Mg deficiency may lead to a further increase of intracellular Na and decrease of intracellular K since Mg is a necessary ion for the function of the Na-K pump. In 297 patients with diuretic treated CHF we found that 42% had hypokalemia, 37% hypomagnesemia and 12% hyponatremia. We also found that 57% had excess muscle Na, 52% had depletion of muscle K and 43% had low muscle Mg. We have also shown that the low muscle K cannot be corrected by K supplementation when there is a concomitant Mg deficiency and that Mg infusions may change the disturbed relation between extra- and intracellular electrolytes towards normal.

Aged↗
PubMed1986

Potassium-sparing diuretics.

The hemodynamic and the endocrine disturbances in congestive heart failure (CHF) impose major changes in electrolyte balance with a retention of sodium and concomitant losses of potassium and magnesium from the body. These changes are of great importance for the development of cardiac dysrhythmias, a diminished glucose tolerance and for the well-being of the patient. The use of conventional diuretics imposes further burdens on the already deranged electrolyte balance. On long-term therapy with conventional diuretics in CHF we observed that approximately 50% of the 297 patients studied had potassium and magnesium deficiencies and an increased sodium content as judged by skeletal muscle biopsies. The magnesium deficiency is especially dangerous since it prevents the cells from keeping their high intracellular potassium concentration unchanged. Potassium substitution is without effect in a magnesium deficiency since magnesium is necessary for the transportation of potassium over the cell membrane against the concentration gradient. In case of magnesium depletion, potassium substitution may even have negative effects on the body potassium content. The reason for this is probably the increase of p-potassium concentration induced by the substitution, leading to an increase of aldosterone secretion. An increase of p-potassium levels by 0.2-0.4 mmol/l may thus result in a 50-100% rise in p-aldosterone concentration. These changes promote further urinary losses of potassium and magnesium. Several studies have demonstrated the positive effects of the potassium-sparing diuretics amiloride, spironolactone and triamterene on p-potassium concentration, but also on the body potassium content.(ABSTRACT TRUNCATED AT 250 WORDS)

Amiloride↗
PubMed1986

Selenium and other trace elements in lung tissue in smelter workers relationship to the occurrence of lung cancer.

In summary lower selenium concentrations were found in the lung cancer group compared to other smelter workers and controls. The two lowest selenium values in the total material were found in two of the lung cancer workers. This is in agreement with earlier reports of lower blood selenium levels in cancer patients (Willett et al 1983, Salonen et al 1984). An increased cancer incidence has also been found in geographical areas with low selenium contents in forage crops (Shamberger et al 1976). Numerous animal experiments have demonstrated an anticarcinogenic effect of selenium. Our conclusion is that selenium might have a protective effect in occupational exposure against at least certain carcinogens causing lung cancer. Looking at the dominant worksites the workers have obviously been exposed to different concentrations of selenium over the years. As selenium has not been particularly under observation, few dust analyses are available, and so the dust load in exposed workers cannot be directly calculated. The excretion rates show individual differences. In three of the seven lung cancer cases we noted that, despite a considerable and continuous exposure to selenium in the course of their work, they had low selenium concentrations in their lung tissue at the time of death. Two other workers in the lung cancer group had also been working at worksites with considerable exposure to selenium. Raised cadmium levels were noted in the lung cancer group.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1986

Swedish trial in old patients with hypertension. A prospective multicentre study in Swedish primary health care.

The Swedish trial in old patients with hypertension was initiated by the Swedish League against Hypertension. It will be conducted as a prospective multicentre study in Swedish primary health care, and will comprise approximately 2 000 patients on active treatment and 2 000 on placebo to be studied for three years. The primary goal with this study is to investigate whether pharmacological treatment of hypertension in men and women aged 70-84 years will reduce the incidence of fatal and nonfatal cardiac and cerebrovascular disease. Before starting the main trial a pilot study comprising 400 patients will be carried out during one year to evaluate all logistical aspects of the study. This pilot study commenced in October 1985.

Adrenergic beta-Antagonists↗
PubMed1986

Peroral glucose tolerance test. Relation to skeletal muscle electrolytes.

Seventy patients on long-term diuretic therapy for arterial hypertension and/or congestive heart failure were investigated with regard to skeletal muscle electrolytes and the results of a peroral glucose tolerance test. A significant correlation was observed between the muscle content of potassium and the ability to handle a glucose load. Thirty patients underwent a second set of samples six months after the first one, 23 of whom had a reduction of their muscle potassium content relative to the first biopsy. They simultaneously demonstrated a significant impairment of glucose tolerance.

Diuretics↗
PubMed1985

Plasma and skeletal muscle electrolytes in patients with Crohn's disease.

Plasma and skeletal muscle electrolytes were measured in 13 patients with Crohn's disease, and in an age- and sex-matched reference group. Patients with Crohn's disease demonstrated significantly lower muscle potassium content (p less than 0.01) than did controls. Patients with extensive involvement of the bowel tended to have lower muscle potassium content. The patient population did not differ significantly from the controls with regard to skeletal muscle magnesium content but displayed a far wider range of values. Our results indicate that potassium depletion is present in nonresected patients with Crohn's disease.

Adult↗
PubMed1985

Skeletal muscle magnesium and potassium determinations: correlation with lymphocyte contents of magnesium and potassium.

Following a lymphocyte separation technique, the lymphocyte content of magnesium and potassium was determined by atomic absorption spectroscopy in 28 subjects. Simultaneously, skeletal muscle biopsies were obtained by a percutaneous technique and analyzed for magnesium and potassium. In this study there was not significant correlation between the lymphocyte and the skeletal muscle content of magnesium or potassium, except in the group of three normal volunteers and nine patients with mild arterial hypertension.

Aged↗
PubMed1985

Aggravation of thiamine deficiency by magnesium depletion. A case report.

A patient with Crohn's disease and long-standing diarrhea resulting in a combined thiamine and magnesium deficiency is presented. Despite massive doses of thiamine i.v., the symptoms of thiamine deficiency could not be suppressed until the magnesium deficiency was corrected as well. This case report emphasizes the dependence of thiamine on magnesium for an adequate function in the body.

Adult↗
PubMed1985

Renal excretion of electrolytes in patients on long-term diuretic therapy for arterial hypertension and/or congestive heart failure.

Renal excretion, skeletal muscle content and plasma concentration of electrolytes were studied in 108 patients on long-term diuretic therapy for congestive heart failure and/or arterial hypertension. As reference populations served a group of 16 healthy volunteers and a group of 22 patients with liver cirrhosis, but not on diuretic therapy. Diuretic therapy was found to deprive the patients of their ability to conserve potassium and magnesium when there was a simultaneous cellular depletion of these ions. Magnesium excretion was found to be correlated to the skeletal muscle magnesium content. An inverted Na/K ratio in urine and a low magnesium excretion were fair indicators of cellular magnesium depletion.

Aged↗
PubMed1985

Protective effect of selenium on lung cancer in smelter workers.

A possible protective effect of selenium against lung cancer has been indicated in recent studies. Workers in copper smelters are exposed to a combination of airborne selenium and carcinogens. In this study lung tissue concentrations of selenium, antimony, arsenic, cadmium, chromium, cobalt, lanthanum, and lead from 76 dead copper smelter workers were compared with those of 15 controls from a rural area and 10 controls from an urban area. The mean exposure time for the dead workers was 31.2 years, and the mean retirement time after the end of exposure 7.2 years. Lung cancer appeared in the workers with the lowest selenium lung tissue levels (selenium median value 71 micrograms/kg wet weight), as compared with both the controls (rural group, median value 110; urban group, median value 136) and other causes of death among the workers (median value 158). The quotient between the metals and selenium was used for comparison: a high quotient indicating a low protective effect of selenium and vice versa. The median values of the quotients between antimony, arsenic, cadmium, lanthanum, lead, chromium, and cobalt versus selenium were all numerically higher among the cases of lung cancer, the first five significantly higher (p less than 0.05) in 28 of the 35 comparisons between the lung cancer group and all other groups of smelter workers and controls. The different lung metal concentrations for each person were weighted according to their carcinogenic potency (Crx4 + Asx3 + Cdx2 + Sbx1 + Cox1 + Lax1 + Pbx1) against their corresponding selenium concentrations. From these calculations the protective effect of selenium was even more pronounced.

Aged↗
PubMed1984

Chromium, cobalt and lanthanum in lung, liver and kidney tissue from deceased smelter workers.

Lung, liver and kidney tissue concentrations of chromium, cobalt and lanthanum from 66 deceased copper smelter workers have been compared with 14 controls. Samples were taken in connection with ordinary autopsies at the local hospital. Neutron activation analysis was used. The mean exposure time for the smelter workers was 30 y, the mean time to date of death after termination of exposure was 7.4 y. A four-fold increase of chromium (p = 0.001) and a two-fold increase of cobalt (p less than 0.001) and lanthanum (p = 0.013) in lung tissue was found for smelter workers compared to controls. Of the smelters nearly one third died from malignancies (approximately 10% from respiratory cancer) and approximately 45% from cardiovascular disease. In the control group nearly 80% died from cardiovascular diseases and no malignancies were found. In lung tissues the concentration of chromium, cobalt and lanthanum did not decline with time after exposure had ended, indicating a long biological half-time. The causes of death could not be related to a single factor. The findings indicate a multifactorial genesis.

Aged↗
PubMed1984

Pulmonary-artery cineangiocardiography to demonstrate cardiac thrombi in patients with cerebral infarction.

The usefulness of pulmonary-artery cineangiocardiography (PACAC) to demonstrate intracardiac thrombi in patients with cerebral infarctions of possible embolic origin has been explored. PACAC was performed in 60 patients (mean age 74 years) with sudden onset of permanent neurological deficits in whom CT scan and CSF analyses had excluded intracerebral hemorrhage. Opacification of the left atrium was excellent in 52 (87%) investigations, acceptable in 7 and poor in 1. Among 33 patients with chronic atrial fibrillation, an atrial thrombus was demonstrated in 8 (24%) and a suspected thrombus in 3. Atrial clot was also demonstrated in a patient with intermittent atrial fibrillation. In 4 out of 14 patients with previous myocardial infarction, a ventricular thrombus was demonstrated. Ventricular clots were detected in 2 of 46 patients without known previous myocardial infarction. No major complications occurred during the investigation. PACAC can be to used in the search for atrial or ventricular thrombi when cardiac source of a cerebral embolus is suspected. About 1 out of 3 patients with atrial fibrillation has remaining intracardiac thrombus after stroke.

Aged↗
PubMed1984

Problems with potassium and magnesium in diuretic-treated patients.

Treatment with thiazides and loop diuretics increase the urinary excretion of potassium and magnesium and the body content of these ions are reduced after long-term treatment. The diuretic-induced magnesium deficiency influences the potassium metabolism. Magnesium is a necessary activator of Na-K-ATPase, which supplies the Na-K pump with energy. Lack of magnesium will therefore impair the pumping of sodium out of the cell and of potassium into the cell. The change of the relationship between extra and intracellular potassium may induce cardiac arrhythmias. Certain groups of patients, such as patients on digitalis therapy, patients with secondary hyperaldosteronism, elderly patients with insufficient dietary habits, and heavy drinkers, run an additional risk of developing potassium/magnesium disturbances. In young patients with uncomplicated essential hypertension, the risk is probably very small.

Diuretics↗