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Biomedical subjects

K Berneis

Publications and source records attributed to K Berneis.

At least 19 recordsLinked to original sources
PubMed2006

Low-density lipoprotein size and cardiovascular risk assessment.

A predominance of small, dense low-density lipoproteins (LDL) has been accepted as an emerging cardiovascular risk factor by the National Cholesterol Education Program Adult Treatment Panel III. LDL size seems to be an important predictor of cardiovascular events and progression of coronary heart disease and evidences suggests that both quality (particularly small, dense LDL) and quantity may increase cardiovascular risk. However, other authors have suggested that LDL size measurement does not add information beyond that obtained by measuring LDL concentration, triglyceride levels and HDL concentrations. Therefore, it remains debatable whether to measure LDL particle size in cardiovascular risk assessment and, if so, in which categories of patient. Therapeutic modulation of LDL particle size or number appears beneficial in reducing the risk of cardiovascular events, but no clear causal relationship has been shown, because of confounding factors, including lipid and non-lipid variables. Studies are needed to investigate the clinical significance of LDL size measurements in patients with coronary and non-coronary forms of atherosclerosis; in particular, to test whether LDL size is associated with even higher vascular risk, and whether LDL size modification may contribute to secondary prevention in such patients.

Anticholesteremic Agents↗
PubMed2006

The significance of low-density-lipoproteins size in vascular diseases.

Low density lipoproteins (LDL) comprise in humans two different main fractions: large, buoyant and small, dense particles. Small, dense LDL particles correlate negatively with plasma HDL levels and positively with plasma triglyceride concentrations and are associated with the metabolic syndrome and increased risk for cardiovascular disease. LDL size seems to be an important predictor of cardiovascular events and progression of coronary heart disease (CHD). In addition, several studies have suggested that therapeutic modulation of specific LDL subclasses may be of great benefit in reducing the atherosclerotic risk. Therefore, LDL size measurement may be of potential value in the clinical assessment and management of patients at high risk of CHD, a category that comprises individuals with non-coronary forms of atherosclerosis: peripheral arterial disease, carotid artery disease, abdominal aortic aneurysm. Potentially, screening for the presence of small, dense LDL in patients with those clinical forms of atherosclerosis may identify those with even higher vascular risk and may contribute in directing specific anti-atherosclerotic treatments in order to prevent new vascular events in the same or another district. However, to-date, not so many studies have investigated the LDL size in patients with non-coronary forms of atherosclerosis and we need to wait for further contributions with larger number of patients, even if available data seem to suggest an association between small, dense LDL and such diseases. The predominance of small dense LDL particles has been accepted as an emerging cardiovascular risk factor by the National Cholesterol Education Program Adult Treatment Panel III but screening for the presence of small, dense LDL particles in patients with non-coronary forms of atherosclerosis has not been so far recommended.

Humans↗
PubMed2004

LDL size: does it matter?

The atherogenic lipoprotein phenotype is characterised by a moderate increase in plasma triglycerides, a decrease in high density lipoprotein cholesterol and the prevalence of smaller denser low density lipoprotein particles. The prevalence of this partially inheritable phenotype is approximately 30% and is a feature of the metabolic syndrome associated with an increased risk for cardiovascular events. The predominance of small dense LDL has been accepted as an emerging cardiovascular risk factor by the adult treatment panel (ATP) III.

Adult↗
PubMed2003

Effects of changes in hydration on protein, glucose and lipid metabolism in man: impact on health.

Alterations of cell volume induced by changes of extracellular osmolality have been reported to regulate intracellular metabolic pathways. Hypo-osmotic cell swelling counteracts proteolysis and glycogen breakdown in the liver, whereas hyperosmotic cell shrinkage promotes protein breakdown, glycolysis and glycogenolysis. To investigate the effect of acute changes of extracellular osmolality on whole-body protein, glucose and lipid metabolism in vivo, we studied 10 male subjects during three conditions: (i) hyperosmolality was induced by fluid restriction and intravenous infusion of hypertonic NaCl (2-5%, wt/vol) during 17 h; (ii) hypo-osmolality was produced by intravenous administration of desmopressin, liberal water drinking and infusion of hypotonic saline (0.4%); and (iii) the iso-osmolality study comprised oral water intake ad libitum. Plasma osmolality increased from 285+/-1 to 296+/-1 mosm/kg (P<0.001 during hyperosmolality, and decreased from 286+/-1 to 265+/-1 mosm/kg during hypo-osmolality (P<0.001). Total body leucine flux ([1-(13)C]leucine infusion technique), reflecting whole-body protein breakdown, as well as whole-body leucine oxidation rate (irreversible loss of amino acids) decreased significantly during hypo-osmolality. The glucose metabolic clearance rate during hyperinsulinaemic-euglycemic clamping increased significantly less during hypo-osmolality than iso-osmolality, indicating diminished peripheral insulin sensitivity. Glycerol turnover (2-[(13)C]glycerol infusion technique), reflecting whole-body lipolysis, increased significantly during hypo-osmolar conditions. The results demonstrate that the metabolic adaptation to acute hypo-osmolality resembles that of acute fasting, that is, it results in protein sparing associated with increased lipolysis, ketogenesis and lipid oxidation and impaired insulin sensitivity of glucose metabolism.

Area Under Curve↗
PubMed2002

Combined stimulation of adrenocorticotropin and compound-S by single dose metyrapone test as an outpatient procedure to assess hypothalamic-pituitary-adrenal function.

The metyrapone test is used to test the hypothalamic-pituitary-adrenocortical axis. The present study aims to assess the diagnostic accuracy of combined stimulation of ACTH and compound-S (CMP-S). In addition, we analyzed the safety and practicability of this test as an outpatient procedure. A total of 327 metyrapone tests were analyzed retrospectively in 185 patients (mean age, 50.3 +/- 15.2 yr). One hundred thirteen patients had one test, and 72 patients had between 2 and 6 tests over 1-3 yr. Most patients suffered from pituitary adenomas (60 macroadenomas, 63 microadenomas) or other pituitary lesions (n = 29). Metyrapone (2 g) was given at 2400 h as an outpatient procedure. Blood samples for analysis of ACTH, CMP-S, and cortisol were taken at 0730 h. Stimulation of adrenal CMP-S and cortisol by pituitary ACTH demonstrated a dose-response curve with the shape of half a geometric parabola. CMP-S reached a plateau when ACTH rose above 175 ng/liter [r = 0.661, P < 0.0001 for ACTH <175 ng/liter; r = 0.083, P = not significant (NS) for ACTH >175 ng/liter], cortisol flattened at ACTH levels above 230 ng/liter (r = 0.633; P < 0.0001 for ACTH < 230 ng/liter; P = NS for ACTH >230 ng/liter). Alternatively, the sum of CMP-S plus cortisol also flattened when ACTH rose above 230 ng/liter (r = 0.696; P < 0.0001 for ACTH <230; P = NS for ACTH > 230 ng/liter). Receiver operating curve analysis defining a cut-off for ACTH at 150 ng/liter demonstrated a sensitivity of 47% and 67% at a cut-off level for CMP-S at 200 or 260 nmol/liter, respectively. The respective specificity was 82% and 68% for CMP-S. This compared with a sensitivity of 71% and specificity of 69% if the sum of CMP-S plus cortisol of 450 nmol/liter were used as cut-off. The response curve between CMP-S and ACTH implies a maximally stimulated adrenal cortex at circulating ACTH levels above 175 ng/liter. Single measurement of CMP-S using the cut-off at 200 nmol/liter, as suggested in the literature, yields a poor sensitivity of only 47% compared with ACTH. Despite the relatively high cross-reactivity of CMP-S in the cortisol assay, the sum of CMP-S and cortisol levels with a cut-off value of 450 nmol/liter yields a better diagnostic accuracy compared with CMP-S alone.

Adrenocorticotropic Hormone↗
PubMed2000

Nutritional supplements combined with dietary counselling diminish whole body protein catabolism in HIV-infected patients.

BACKGROUND: Weight loss and protein malnutrition are frequent complications in HIV-infected patients. The effect of an oral nutritional supplement combined with nutritional counselling on whole body protein metabolism was assessed. MATERIALS AND METHODS: HIV-infected individuals with a body mass index < 21 kg m-2 or CD4-T cells < 500 micro L-1 in stable clinical condition were randomly allocated to [1] receive either oral nutritional supplements (containing 2510 kJ, complete macro- and micronutrients) and dietary counselling (n = 8), or [2] identical monitoring but no supplements or specific nutritional advice (controls, n = 7). Whole body leucine kinetics and leucine oxidation rate were determined by [1-13C]-leucine infusions and lean and fat mass were measured before and 12 weeks after intervention. RESULTS: Leucine oxidation (protein catabolism) decreased in the group receiving nutritional intervention from 0.33 +/- 0.02 to 0.26 +/- 0.02 micromol kg-1 min-1 after 12 weeks (P < 0.05; P < 0.05 vs. control group) but remained unchanged in the control group. Whole body leucine flux showed a tendency to decrease in the intervention group from 1.92 +/- 0.19 to 1.73 +/- 0.14 micromol kg-1 min-1 (P = 0.07) and remained unchanged in the control group (2.21 +/- 0.16 and 2.27 +/- 0.14 micromol kg-1 min-1, respectively). Lean body mass determined by bioelectrical impedance analysis increased in the nutritional intervention group from 84 +/- 2 to 86 +/- 2 per cent (P < 0.05) and fat mass decreased from 17 +/- 2 to 14 +/- 2 per cent (P < 0.05) of total body weight whereas neither mass changed in the control group. Nutritional intervention had no significant effect on lymphocyte CD4 counts, on plasma TNFR 55, TNFR 75 and ILR 2 concentrations and on quality of life. CONCLUSIONS: The data demonstrate an anticatabolic effect of nutritional supplements combined with dietary counselling in HIV-infected subjects. They suggest that diminished whole body protein catabolism resulted in a change of body composition (increased lean mass, decreased fat mass).

Body Composition↗
PubMed2000

Bioelectrical impedance analysis during acute changes of extracellular osmolality in man.

BACKGROUND & AIMS: Bioelectrical impedance analysis (BIA) is widely used as an inexpensive and noninvasive method to provide estimates of body compartments such as total body water, lean body mass and fat mass. The present study was performed to test the reliability of this method during acute changes of extracellular osmolality in eight young health men. METHODS: Hyperosmolal isohydration was achieved by overnight infusions of hypertonic saline solutions (2 and 5% NaCl) and thirsting, and hypoosmolal hyperhydration by drinking of free water and overnight application of desmopressin. The control study (isoosmolality) consisted of oral water ad libitum. RESULTS: When plasma osmolality and sodium concentrations increased (from 285 +/- 1 to 296 +/- 1 mmol/kg (P<0.001) and from 141.9 +/- 0.7 to 148.3 +/- 0.6 mmol/l (P<0.0001)) and total body water remained unchanged, body impedance decreased and calculated total body water increased from 42.7 +/- 2.7 to 45.6 +/- 2.3 liters (P<0.03). In contrast, during hypoosmolal hyperhydration total body water increased by 1.56 +/- 0.17 kg and plasma osmolality decreased from 285 +/- 1 to 272 +/- 1 mmol/kg (P<0.001) and plasma sodium concentrations from 142 +/- 0.5 to 134.8 +/- 0.4 mmol/l (P<0.0001). In spite of these changes of body water, impedance measurements and calculated total body water remained unchanged. During conditions of isoosmolal isohydration (as demonstrated by unchanged plasma sodium concentrations and osmolality) the measurements by BIA also remained unchanged. CONCLUSIONS: Measurements of total body water using BIA under conditions of unknown hydration status (hyper-, hypo- or isohydration) and unknown osmolality (hyper-, hypo- or isoosmolality) may not be reliable. Therefore bioelectrical impedance analysis is not a suitable bedside method to assess changes of body compartments under unstable hydration status.

Adult↗
PubMed1999

Effects of intradialytic parenteral nutrition in chronic haemodialysis patients with malnutrition: a pilot study.

BACKGROUND AND AIMS: Protein and calorie malnutrition is frequently observed in chronic haemodialysis (HD) patients. Recently it has been suggested that intradialytic nutritional support with amino acids may improve nutritional status and increase immunocompetence. The aim of this study was to evaluate the effects of intradialytic infusion of amino acids, lipids and glucose on body composition and other parameters of nutritional status in patients undergoing HD. METHODS: Seven patients with a mean age of 77 +/- 6 years (range, 60-86 years), a mean BMI of 20.1 +/- 2.8 (range, 16.1-24.4) and clinical signs of malnutrition participated in the study (mean time on HD, 51 +/- 36 months). HD was performed 12 hours per week with bicarbonate as a buffer and a polysulfon capillary dialyzer (F-60). During the 3-month period of intervention the patients received an intradialytic parenteral solution during the regular scheduled dialysis treatment, containing amino acids (12 g s/h), a glucose 15% solution (37.5 g/h) and a fat emulsion (12.5 g/h). RESULTS: (mean +/- SEM) Total calorie intake increased from 1550 +/- 63 to 2255 +/- 114 (kcal/24 h) p < 0.01, during the intervention period and body weight increased from 49.9 +/- 5.9 to 51.9 +/- 5.7 kg (p < 0.005). Fat mass and lean body mass (bioelectrical impedance analysis, BIA) increased from 13.2 +/- 2.6 to 14.2 +/- 2.6 (p < 0.02) and from 36.9 +/- 3.2 to 37.9 +/- 3.2 kg (p < 0.003), respectively. Plasma concentrations of albumin, total protein, transferrin, leptin IGF-I, IGFBP-3 and the protein catabolic rate remained unchanged. CONCLUSIONS: Supplementary intravenous intradialytic nutrition in chronic HD patients with malnutrition increased total body weight by effecting equivalent increases in lean body and fat masses.

Aged↗
PubMed1999

Effects of hyper- and hypoosmolality on whole body protein and glucose kinetics in humans.

To investigate the effect of acute changes of extracellular osmolality on whole body protein and glucose metabolism, we studied 10 male subjects during three conditions: hyperosmolality was induced by fluid restriction and intravenous infusion of hypertonic NaCl [2-5%; (wt/vol)] during 17 h; hypoosmolality was produced by intravenous administration of desmopressin, liberal water drinking, and infusion of hypotonic saline (0.4%); and the isoosmolality study consisted of ad libitum oral water intake by the subjects. Leucine flux ([1-13C]leucine infusion technique), a parameter of whole body protein breakdown, decreased during the hypoosmolality study (P < 0. 02 vs. isoosmolality). The leucine oxidation rate decreased during the hypoosmolality study (P < 0.005 vs. isoosmolality). Metabolic clearance rate of glucose during hyperinsulinemic-euglycemic clamping increased less during the hypoosmolality study than during the isoosmolality study (P < 0.04). Plasma insulin decreased, and plasma nonesterified fatty acids, glycerol, and ketone body concentrations and lipid oxidation increased during the hypoosmolality study. It is concluded that acute alterations of plasma osmolality influence whole body protein, glucose, and lipid metabolism; hypoosmolality results in protein sparing associated with increased lipolysis and lipid oxidation and impaired insulin sensitivity.

Adult↗
PubMed1999

Effects of IGF-I combined with GH on glucocorticoid-induced changes of bone and connective tissue turnover in man.

Chronic glucocorticoid therapy results in negative bone and connective tissue balance. To assess the effects of GH and a combination of IGF-I and GH, 24 healthy male volunteers received in a double blind fashion either recombinant human GH (0.3 IU/kg per day s.c.), or a combination of GH (0.3 IU/kg per day s.c.) and IGF-I (80 microgram/kg per day s.c.) or placebo (saline s.c.) during 6 days of methylprednisolone (0.5 mg/kg per day) treatment. Methylprednisolone decreased serum osteocalcin concentrations during placebo treatment from 32.9+/-2.1 to 9.0+/-1.4 microgram/l (P<0.0001), indicating diminished osteoblast activity, and procollagen type I (PICP) and procollagen type III (PIIINP) to 46 and 70% of baseline respectively (P<0.005), indicating diminished bone (PICP) and soft tissue collagen synthesis (PIIINP). Urinary excretion of pyridinoline, deoxypyridinoline and hydroxyproline increased during treatment with methylprednisolone alone, indicating increased bone resorption (P<0.05 or less). The combination of GH and IGF-I resulted in a significant blunting of the methylprednisolone effect on serum PICP and PIIINP concentrations (P<0.005 or less vs placebo); this effect was in part due to IGF-I, since serum PICP concentrations decreased less in the combination group than during GH treatment alone (P<0.05). In the groups receiving GH and GH combined with IGF-I, urinary hydroxyproline excretion increased more when compared with methylprednisolone alone (P<0.05 or less). These findings demonstrate that only the combination of GH and IGF-I, but not GH alone, markedly counteracts diminished bone and body collagen synthesis caused by glucocorticoids, whereas connective tissue resorption is enhanced during treatment with GH alone and in combination with IGF-I.

Alkaline Phosphatase↗
PubMed1997

Ethanol exerts acute protein-sparing effects during postabsorptive but not during anabolic conditions in man.

Ethanol abuse is frequently associated with protein malnutrition. To assess the acute effects of ethanol on whole-body protein metabolism, [1-13C]leucine kinetics were measured in eight postabsorptive normal male subjects three times, ie, during administration of two doses of ethanol (dose 1, 0.52 g/kg during 2 hours and 0.3 g/kg during 3 hours; dose 2, 0.69 g/kg during 2 hours and 0.3 g/kg during 3 hours) and during saline (controls). During the last 2 hours of the studies, glucose, insulin, and amino acids were infused to assess the effects of ethanol on protein kinetics under anabolic conditions (euglycemic clamp). The decreases in leucine flux (reflecting whole-body protein breakdown) and nonoxidative leucine disappearance (a parameter of protein synthesis) during saline infusion were abolished in both ethanol protocols (P < .05 or less v saline). The rate of leucine oxidation decreased during the higher dose of ethanol compared with saline (P < .005), indicating an anticatabolic effect. During anabolic conditions (clamp), leucine flux and nonoxidative leucine disappearance were significantly higher in both ethanol studies compared with saline (P < .05). Resting energy expenditure (REE) and oxygen consumption (VO2) during the euglycemic clamp increased to a greater degree during both ethanol studies than during saline (P < .05 or less). Thus, an elevation of blood ethanol concentrations to the levels observed in social drinking results in a net anticatabolic effect (diminished leucine oxidation) when ethanol is administered alone. However, during administration of other nutritional substrates, the anticatabolic effect was not detectable, possibly because ethanol enhanced nutrient-induced thermogenesis.

Adult↗
PubMed1997

Effects of insulin-like growth factor I combined with growth hormone on glucocorticoid-induced whole-body protein catabolism in man.

Treatment with insulin-like growth factor I (IGF-I) alone failed to affect glucocorticoid-induced protein catabolism in a previous study from our laboratory. To assess the effects of the combination of IGF-I and GH in a similar protocol, 24 normal subjects received (in a double-blind, randomized, placebo-controlled manner) s.c. injections of either GH alone (0.3 IU/kg.day), the combination of IGF-I (80 micrograms/kg.day) and GH (0.3 IU/kg.day), or placebo for a period of 6 days during which they were treated with methylprednisolone (0.5 mg/kg.day). Whole-body protein kinetics measured, using the [1-13C]-leucine infusion technique, demonstrated that leucine flux (a parameter of protein breakdown) increased during administration of glucocorticoids alone (placebo group) and during GH-treatment, whereas the glucocorticoid-induced increase was abolished during IGF-I plus GH (P < 0.03 vs. GH). Leucine oxidation (a parameter of irreversible protein catabolism) increased in the placebo group (+60 +/- 14.5%, P < 0.005, day 7 vs. day 1), remained unchanged in the GH group (+2.5 +/- 10%), and decreased in the combination group (-17.7 +/- 3.3%, P < 0.002, day 7 vs. day 1). Glucose MCR decreased in the group receiving placebo (P < 0.05) and remained unchanged during combined treatment with IGF-I plus GH. It is concluded that glucocorticoid-induced protein, catabolism (leucine oxidation) is abolished during coadministration of GH (anticatabolic effect), whereas treatment with IGF-I and GH results in a net anabolic effect without adverse effects on peripheral glucose clearance.

Adult↗
PubMed1996

Metabolic actions of growth hormone: direct and indirect.

GH may exert metabolic effects either directly or indirectly through increased production of IGF-I. GH administration increases circulating IGF-I levels via stimulation of hepatic synthesis and secretion of IGF-I; it may also enhance local IGF-I synthesis, which exerts paracrine or autocrine effects. Figure 2 summarizes the metabolic effects of GH and IGF-I. Administration of GH and IGF-I in adult humans has been demonstrated to enhance protein anabolism. Combined administration of GH and IGF-I was observed to be more anabolic than either IGF-I or GH alone. Evidence is presented that protein accretion results mainly from direct effects of GH on tissues; additional indirect effects via IGF-I production are also likely. Administration of GH has been reported to produce carbohydrate intolerance with elevated plasma insulin levels, resulting from insulin resistance. in contrast, insulin sensitivity increased during administration of IGF-I, which exerts hypoglycaemic effects even with concomitant suppression of insulin secretion. A major direct metabolic effect of GH is to increase fat mobilization and oxidation, and thereby to reduce total body fat; there is no evidence that IGF-I acts directly on adipose tissue in vivo. GH administration results in sodium retention via stimulation of Na-K-ATPase. It is suggested that part of the effects of GH on tubular function (e.g. phosphate reabsorption) are mediated via IGF-I. Energy expenditure may be increased by administration of either GH or relatively high doses of IGF-I. One of the reasons for this phenomenon is an increase in lean body mass; GH may increase energy expenditure additionally be enhancing the production of T3 and by increasing lipid oxidation.

Adult↗
PubMed1996

Effects of glucocorticoids and of growth hormone on serum leptin concentrations in man.

Recent data suggest an involvement of the ob gene and its product leptin in the regulation of body fat. To assess the effects of glucocorticoids and growth hormone (GH) on serum leptin and body fat, 30 normal subjects received methylprednisolone (0.5 mg.kg-1.day-1) per os for 7 days and 15 subjects received in addition sc injections of GH (0.15 IU.kg-1.day-1) twice daily (combination group). Serum leptin levels increased both in the glucocorticoid group (p < 0.02) and in the combination group (p < 0.002). When body fat was estimated by bioelectrical impedance analysis it decreased during combined treatment and remained unchanged in the glucocorticoid group. Plasma insulin concentrations increased in both groups. Resting energy expenditure (indirect calorimetry) increased in the combination group and remained unchanged in the glucocorticoid group. The finding of increased serum leptin concentrations during treatment with glucocorticoid and GH suggests that serum leptin is regulated by glucocorticoids, possibly though changes in insulin secretion, independently of changes of body fat mass.

Adult↗
PubMed1983

Characterization of the brown pigment of the mucosa of the urinary tract.

The brownish discoloration of the mucosa of the urinary tract which is present in 10-42% of the patients with chronic abuse of analgesics containing phenacetin is, like the discoloration of liver, skin and cartilage, due to lipids similar in type to those in the lipid component of lipofuscin.

Humans↗
PubMed1979

The morphologic diagnosis of analgesic (phenacetin) abuse.

A number of different morphologic characteristics were examined to determine their relative values in establishing a purely morphologic diagnosis of phenacetin abuse. These included hyperpigmentation of the skin, the costal cartilages, the liver, and the renal tubules, and capillarosclerosis of the lower urinary tract. Hyperpigmentation of the skin, liver, and renal tubules cannot be used in the diagnosis of phenacetin abuse. Massive brown pigmentation of the costal cartilages in patients under 60 years of age suggests phenacetin abuse, but even this morphologic parameter, when used alone, is insufficient to establish a definite diagnosis. Capillarosclerosis in the lower urinary tract does, however, permit one to diagnose phenacetin abuse with certainty, as it is found exclusively in this condition.

Adolescent↗
PubMed1976

Distribution of sulfonamides and sulfonamide potentiators between red blood cells, proteins and aqueous phases of the blood of different species.

The uptake of sulfonamides and sulfonamide potentiators by plasma albumin, red blood cells and hemoglobin of man, ox, rabbit and mouse has been determined. From the figures obtained the distribution of these compounds between cells, macromolecules and aqueous phases of blood has been calculated. In most cases more than 50% of a total sulfonamide in blood is bound to plasma albumin. The time necessary for establishment of concentration equilibrium of the drugs investigated between erythrocytes and surrounding medium varies between a few seconds and several minutes, differences between the species being encountered. Hemoglobin binding of the drugs is much smaller than albumin binding. Nevertheless, drug concentration within the erythrocytes is generally higher than in the surrounding medium.

Animals↗