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Biomedical subjects

H E Norbeck

Publications and source records attributed to H E Norbeck.

18 recordsLinked to original sources
PubMed1994

'Person under train' incidents from the subway driver's point of view--a prospective 1-year follow-up study: the design, and medical and psychiatric data.

UNLABELLED: From the subway driver's point of view, a 'person under train' (PUT) incident is a serious life event. This study focuses on the 1-yr consequences of such events. Follow-up was made 3 wk, 3 months and 1 yr after the event. 40 consecutive PUT subway drivers were followed. For each PUT driver, a control driver matched with regard to gender, age and country of birth was followed at identical intervals. MAIN RESULTS: the PUT group had significantly more sick days during the interval from the event to 3 wk later. During the period 3 wk to 3 months after the event no difference between the groups was observed. From 3 months to 1 yr after the PUT significantly more days were again reported by the PUT group. 38% in the PUT groups vs 14% in the control group had at least 1 month of sickness absence during this period. A mild acute psychophysiological reaction was observed 3 wk after the event, with elevated prolactin and increased sleep disturbance in the PUT group. Such acute reactions were transitory and not correlated with long-term sick leave, which was predicted independently, however, by a high plasma cortisol level (analysed in men) and a high depression score. Drivers in the group with seriously injured victims were absent from work for longer periods than drivers in the groups with mildly injured or dead victims. PUT victims described a successively worsened psychosocial work situation during the 12 months of follow-up whereas the drivers in the control group described an unchanged situation.

Absenteeism↗
PubMed1994

Exposure of bus and taxi drivers to urban air pollutants as measured by DNA and protein adducts.

Urinary 1-hydroxypyrene, lymphocyte DNA adducts, serum protein-bound PAH and hemoglobin-bound alkene adducts were analysed from 4 groups of non-smoking men: urban and suburban bus drivers, taxi drivers and suburban controls. The only differences between the groups were in DNA adducts between suburban bus drivers and controls, and in DNA adduct and plasma protein PAH-adducts between taxi drivers and controls.

Air Pollutants↗
PubMed1994

DNA adducts among personnel servicing and loading diesel vehicles.

The levels of aromatic DNA adducts were compared by the 32P-postlabeling assay between the lymphocytes isolated from bus maintenance and truck terminal workers, using hospital mechanics as a control group. The adduct levels were elevated in all the bus and truck terminal workers. Within the bus maintenance personnel, garage workers had the highest levels of adducts. Within the terminal workers those driving diesel forklifts had the highest adduct levels. The results suggest that diesel exhaust contributes to the level of adducts.

DNA↗
PubMed1991

Effects of intravenous nutrition on lipoprotein metabolism, body composition, weight gain and uremic state in experimental uremia in rats.

The effect on serum lipids, lipoprotein fractions, body composition, weight gain and uremic state of including fat in intravenous nutrition was evaluated in rats with chronic uremia. Uremic rats were given high energy (1385 kJ.kg body weight-1.day-1), low nitrogen (0.6 g N.kg body weight-1.day-1) total parenteral nutrition (TPN) for 12 d with either glucose or glucose plus 30% lipids (Intralipid) as the energy source. Additional uremic and nonuremic groups were fed a standard diet orally. During TPN, serum triglyceride and cholesterol levels were slightly higher in rats fed lipid-based TPN compared to those administered glucose-based TPN or fed the oral diet; but there were no differences 8 h after feeding. The serum lipoprotein fractions showed accumulation of lipids in LDL resulting from the lipid-based TPN but no differences in VLDL. In orally fed uremic rats, more lipids were found in HDL than in the TPN-treated rats. The fractional clearance of the fat emulsion was normal and independent of the nutrition composition. Uremic rats administered lipid-based TPN for 21 d had the same weight gain as orally fed, nonuremic control rats (23 +/- 3 vs. 22 +/- 2%); glucose-based TPN did not support normal growth (10 +/- 1%). Uremic rats fed orally did not grow and retained significantly more body water than TPN-fed uremic rats. In uremic animals, lipid-based TPN also was associated with normal body composition despite significantly lower levels of carnitine in plasma, skeletal muscle and heart tissue.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1986

Serum lipids and lipoproteins during continuous ambulatory peritoneal dialysis.

The effects of continuous ambulatory peritoneal dialysis (CAPD) on serum lipids and lipoproteins over the initial year of therapy were studied in 23 uremic patients. Lipoprotein abnormalities typical for the uremic dyslipoproteinemia were present at the start of CAPD. During the first months of CAPD these abnormalities were accentuated. The concentrations of very low density lipoprotein (VLDL)-cholesterol (CHOL), low density lipoprotein (LDL)-CHOL, serum CHOL and serum triglycerides (TG) increased significantly. However, after one year of CAPD only the VLDL-CHOL and serum CHOL levels remained significantly higher than the baseline values. VLDL-TG, VLDL-CHOL and serum TG, and the changes of these variables over the study period, correlated with the amount of glucose in the dialysates. We conclude that the continuous peritoneal absorption of glucose (100-200 g/24 h) during CAPD contributes to potentially atherogenic changes in serum lipids and lipoproteins. However, some of the changes are transitory, indicating an adaptation to the peritoneal glucose load.

Adult↗
PubMed1983

Serum lipids and lipoproteins in schizophrenic patients with normal renal function treated with hemodialysis.

To study the effect of hemodialysis on serum lipids and lipoproteins, five patients with normal renal function who had undergone hemodialysis for schizophrenic symptoms for 10 weeks in a crossover study were investigated. Active or sham (no dialysate flow through the filter) dialysis was instituted randomly. Serum lipids were isolated by ultracentrifugation and precipitation before and after each period. High density lipoprotein (HDL) cholesterol levels were constantly low and correlated negatively with serum alkaline phosphatase concentrations (p less than 0.05). Serum and very low density lipoprotein (VLDL) triglycerides and VLDL cholesterol increased during active, and to a lesser extent during sham, dialysis. Dialysis of this intensity does not affect HDL. The low levels may be secondary to subclinical cholestasis from neuroleptic drug treatment. Some individuals may develop hypertriglyceridemia of unknown pathogenesis during hemodialysis. Both these lipoprotein abnormalities are risk factors for the development of atherosclerosis.

Adult↗
PubMed1982

Treatment of uremic hypertriglyceridaemia with bezafibrate.

Elevated triglycerides (TG) in serum and in very low density lipoproteins (VLDL), and a high cholesterol concentration in VLDL but low concentration in high density lipoproteins (HDL), are some characteristics of chronic, non-nephrotic renal failure (CRF). We have given the clofibrate analogue bezafibrate in a reduced dosage, calculated from individual single dose administrations of bezafibrate, to 12 patients with CRF, to treat their abnormal lipid levels. Serum TG were lowered by 40% due to a decrease in the VLDL fraction by 49%. High levels of LDL cholesterol were lowered, while low levels increased during treatment. HDL cholesterol increased by 17%. Studies of the removal rate of TG-rich particles from the blood and of adipose tissue metabolism could not explain the changes in serum lipids. No subjective or objective side effects from the drug were seen. An individualized dosage of bezafibrate and repeated checks of the serum concentrations of the drug are recommended during long-term treatment of uremic patients.

Bezafibrate↗
PubMed1982

Intravenous fat tolerance test with Intralipid in chronic renal failure.

The intravenous fat tolerance test with Intralipid has been used to evaluate the triglyceride (TG) removal capacity in 34 male patients with varying degree of chronic renal failure (CRF). The investigations were repeated in 10 patients after 2-3 years when the renal function had deteriorated further. The fractional removal rate of Intralipid (k2) was low compared to controls, regardless of degree of renal function, etiology of renal disease or treatment with antihypertensive drugs. The k2 value did not change in patients investigated twice, although there was a considerable decrease in renal function. Both in patients and controls there was a strong negative correlation between k2 and the very low density lipoprotein (VLDL) TG concentration. However, at the same k2 value, the VLDL TG concentration was higher in patients than in controls. These data suggest that the hypertriglyceridemia commonly seen in patients with CRF is caused both by an increased VLDL production and a decreased VLDL removal from the circulation. Furthermore, these changes in TG metabolism are induced early in the course of renal insufficiency.

Fat Emulsions, Intravenous↗
PubMed1982

Fatty acid composition of serum and adipose tissue lipids in males with chronic renal failure. Relations to serum lipoproteins and clinical factors.

We have analysed the fatty acid composition of serum cholesterol esters (CE), phospholipids (PL) and triglycerides (TG) and of adipose tissue (AT) lipids in 72 males and chronic renal failure (CRF). Sixteen patients were treated with protein-poor diet. 16 with hemodialysis. The results have been related to clinical aspects of the disease and to abnormalities in serum lipid and lipoprotein concentrations. The major findings were high relative content of oleic acid and a low relative content of linoleic acid in all lipids in the diet-treated group compared to both controls and to the untreated and dialysed patients. Tendencies in the same directions were seen also in the untreated subjects, significant for oleic and linoleic acid in CE and for oleic acid in PL. These changes did not correlate to serum of lipoprotein lipids, or to serum creatinine concentrations in patients not on diet or dialysis, indicating that other factors are more important in modifying the fatty acid metabolism in CRF. The composition of the protein-poor diet, which was rich in fat but low in linoleic acid in relation to oleic acid, is probably a major factor explaining our findings in the diet-treated group. Since low levels of linoleic acid in plasma and AT lipids have been suggested to be a risk factor for atherosclerosis, more attention should be paid to the content and composition of dietary fat in order to prevent the occurrence of such low levels.

Adipose Tissue↗
PubMed1981

Clinical pharmacokinetics of bezafibrate in patients with impaired renal function.

The pharmacokinetics of the new lipid-lowering drug bezafibrate has been investigated in patients with impaired renal function and hyperlipoproteinaemia. 12 patients received a single oral dose of bezafibrate 300 mg. Plasma and urine samples were collected and bezafibrate was analyzed by gas chromatography. Eight of the patients had moderately impaired renal function, with a creatinine clearance between 20 and 40 ml/min; the mean plasma half-life of bezafibrate in them was 7.8 +3.9 h (SD) and the plasma clearance was 0.03 +0.02 1/kg . h. Three of the patients had a creatinine clearance greater than 40 ml/min; in them the plasma half-life was shorter, 4.6 +1.2 h, and the plasma clearance was higher, 0.06 +0.01 1/kg . h. The slowest elimination of bezafibrate was found in a patient with a creatinine clearance of only 13 ml/min. This patient had a plasma half-life of 20.l h, which is ten times longer than has been reported in healthy volunteers. Thus, when treating hyperlipoproteinaemia in patients with impaired renal function, the dosage of bezafibrate must be individualized because of its reduced renal elimination.

Adult↗
PubMed1980

Increased frequency of late pre- beta lipoproteins (LP beta) in isolated serum very low density lipoproteins in uraemia.

Hypertriglyceridaemia, which is caused by raised levels of the triglyceride rich serum very low density lipoproteins (VLDL), is common in uraemia. Here we report qualitative studies on VLDL in this condition. VLDL were isolated from serum of 137 uraemic patients by ultracentrifugation, subjected to agarose electrophoresis and stained for lipids. An increased frequency of presence of electrophoretically slow migrating, discrete VLDL band, the so-called late pre- beta lipoproteins, LP beta, was found, 76% in uraemia versus 30% in controls. Patients on haemodialysis had a higher frequency of LP beta than those not on dialysis, 94% versus 69%. Furthermore the cholesterol/triglyceride ratio of VLDL was raised by about 30% in uraemia. Since the cholesterol enriched LP beta is believed to represent an end stage of the catabolism of VLDL these data suggest that there is a delayed clearance of VLDL remnants in uraemia. In haemodialysis patients heparin might have contributed to the higher frequency of LP beta.

Cholesterol↗
PubMed1980

Metabolic effects of continuous ambulatory peritoneal dialysis.

Prospective studies concerning protein, carbohydrate, and lipid metabolism were performed in 19 CAPD patients. After 2-4 months on CAPD the mean nitrogen balance was positive (3.14 +/- 1.98 g N/day) and was correlated with protein and energy intake as well as with the increase in body weight. Plasma free amino acid concentrations were normal, but the tyrosine/phenylalanine ratio was decreased compared with healthy subjects. In spite of the excessive glucose load, there was no further deterioration in glucose tolerance. Serum concentrations of TG and CHOL were increased due to a rise of VLDL-TG and VLDL-CHOL.

Adult↗
PubMed1976

Serum lipid and lipoprotein concentrations in chronic uremia.

The concentrations of triglycerides and cholesterol have been determined in total serum and in the three major serum lipoprotein classes--very low (VLDL), low (LDL) and high (HDL) density lipoproteins-after an overnight fast in 39 patients with chronic uremia of more than 2 years' duration and with serum creatinine above 350 mumol/l. The values were compared with data from healthy male and female controls. The findings were similar for male and female uremics. Hypertriglyceridemia was common while serum cholesterol tended to be normal or subnormal. With the conventional typing system for hyperlipidemia, types II A, III and IV were present in 6,9 and 30%,respectively. The tryglyceride and cholesterol concentrations in VLDL were increased, while their normal relation for this lipoprotein class was maintained. In LDL the concentration of tryglycerides was increased, while that of cholesterol was low. The LDL composition, therefore, was changed to be more triglyceride-rich than normal. The changes in concentration and composition of LDL indicated that the levels of LDL 1 were raised and of LDL 2 decreased in chronic uremia. Increased levels of LDL tryglycerides occurred more frequently (40%) than increased levels of VLDL triglycerides (33%). The most striking and consistent lipoprotein abnormality was a low HDL cholesterol, which was not related to high VLDL levels. The HDL tryglycerides, on the other hand, tended to be somewhat high. The importance of the raised levels of the triglyceride-rich VLDL and LDL 1 and the decreased levels of HLD cholesterol for the rapid development of atherosclerotic vascular diseases which occur in chronic uremia is discussed. It is of interest in this context that both total cholesterol and LDL cholesterol were low. The possible mechanisms underlying the lipoprotein abnormalities in chronic uremia are discussed and it is suggested that they are complex.

Adult↗
PubMedDate not supplied

"Person under train" incidents: medical consequences for subway drivers.

UNLABELLED: From the subway driver's point of view, a "person under train" (PUT) incident is a serious life event. This study focuses on the 1-year consequences of such events. Follow-up was made 3 weeks, 3 months, and 1 year after the event. Forty consecutive PUT subway drivers were followed. For each PUT driver, a control driver matched with regard to gender, age, and country of birth was followed at identical intervals. MAIN RESULTS: The PUT group had significantly more sick days during the interval from the event to 3 weeks later. During the period 3 weeks to 3 months after the event no difference between the groups was observed. From 3 months to 1 year after the PUT significantly more days were again reported by the PUT group. Thirty-eight percent in the PUT group versus 14% in the control group had at least 1 month of sickness absence during this period. A mild acute psychophysiological reaction was observed 3 weeks after the event, with elevated prolactin and increased sleep disturbance in the PUT group. Such acute reactions were transitory and not correlated with long-term sick leave, which was predicted independently, however, by a high plasma cortisol level (analyzed in men) and a high depression score. Drivers in the group with seriously injured victims were absent from work for longer periods than drivers in the groups with mildly injured or dead victims.

Absenteeism↗