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Biomedical subjects

G A Heidendal

Publications and source records attributed to G A Heidendal.

At least 19 recordsLinked to original sources
PubMed1999

Microdialysis assessment of local adipose tissue lipolysis during beta-adrenergic stimulation in upper-body-obese subjects with type II diabetes.

The present study was designed to investigate indicators of abdominal adipose tissue lipolysis (microdialysis), and subcutaneous adipose tissue blood flow and whole-body lipolysis, in obesity-associated type II diabetes during overnight-fasted conditions (baseline) and during intravenous infusion of the non-selective beta-agonist isoprenaline. Basal subcutaneous adipose tissue blood flow and isoprenaline-induced increases in adipose tissue blood flow were not significantly different between subjects with type II diabetes and non-obese, non-diabetic controls. Adipose tissue interstitial glycerol concentrations were significantly higher in subjects with type II diabetes compared with controls (P<0. 01), and during isoprenaline infusion there was a decrease in interstitial glycerol in both groups (P<0.001). Arterial glycerol concentrations were higher in subjects with type II diabetes compared with controls (P<0.05), whereas the increases in arterial glycerol concentration in response to isoprenaline infusion were of a similar magnitude in the two groups. Estimated subcutaneous adipose tissue glycerol release was not significantly different between the groups (controls and subjects with type II diabetes: baseline, -129+/-32 and -97+/-72 micromol.min(-1).100 g(-1) adipose tissue respectively; isoprenaline, -231+/-76 and -286+/-98 micromol. min(-1).100 g(-1) respectively). Values for fat oxidation were not significantly different between groups, whereas the isoprenaline-induced increase in fat oxidation tended to be less pronounced in subjects with type II diabetes compared with controls (0.022+/-0.008 and 0.038+/-0.003 g/min respectively; P=0.058). Thus estimated basal subcutaneous adipose tissue glycerol release, expressed per unit of fat mass, is not different in controls and in subjects with type II diabetes. Additionally, the isoprenaline-induced increases in indicators of local abdominal subcutaneous adipose tissue, systemic lipolysis and abdominal adipose tissue blood flow responses were comparable in obese subjects with type II diabetes and in controls. The last two findings contrast with previous data from obese subjects, indicating that the regulation of lipolysis may differ in obesity and obesity-associated type II diabetes.

Adipose Tissue↗
PubMed1999

Body composition in renal transplant patients: bioimpedance analysis compared to isotope dilution, dual energy X-ray absorptiometry, and anthropometry.

Whether multifrequency bioelectrical impedance analysis (MF-BIA), a relatively new method for measuring body composition, is also applicable for accurate body composition measurements in renal transplant (RTx) patients is not known. Therefore, the use of MF-BIA is validated in 77 RTx patients with a stable renal function at least 2 yr posttransplantation. MF-BIA is compared to isotope dilution techniques for measurement of body water compartments, and to dual energy x-ray absorptiometry (DEXA) and anthropometry for measurement of fat and fat free mass. Finally, DEXA and anthropometry are compared to each other. Method agreement is assessed by intraclass correlation coefficients (ICC) and plotted by Bland and Altman analysis. MF-BIA significantly underestimates total body water (TBW, 0.7+/-2.1 L) and overestimates the extracellular water (ECW, 3.3+/-1.8 L) compared to isotope dilution; the ICC between both techniques is 0.943 for TBW and 0.846 for ECW. The percentage body fat (BF) measured by MF-BIA is significantly higher than both BF measured by DEXA (3.4+/-4.7%) or by anthropometry (5.5+/-5.2%). The ICC between MF-BIA and DEXA is 0.887 and between MF-BIA and anthropometry 0.856. BF measured by DEXA is significantly higher than BF measured by anthropometry (2.1+/-4.4%); their ICC is 0.913. In conclusion, MF-BIA seems to be suitable for measurement of TBW in RTx patients; however, method agreement between isotope dilution and MF-BIA for the measurement of ECW is not satisfactory. In the assessment of fat and fat free mass, the reliability of MF-BIA appears to be questionable. Method agreement between DEXA and anthropometry seems to be slightly better.

Absorptiometry, Photon↗
PubMed1998

Dual-energy X-ray absorptiometry in the clinical evaluation of body composition and bone mineral density in patients with chronic obstructive pulmonary disease.

BACKGROUND: Depletion of fat-free mass (FFM) occurs in a considerable number of patients with chronic obstructive pulmonary disease (COPD). OBJECTIVE: The goal of the study was to determine whether dual-energy X-ray absorptiometry (DXA) is an applicable method in the clinical evaluation of body composition in COPD. DESIGN: In a cross-sectional study in 79 COPD patients participating in a pulmonary inpatient program and in 23 healthy volunteers, DXA was compared with deuterium dilution (Deu) in the estimation of FFM. Bone mineral density (BMD), a DXA measurement, was also compared between the 2 groups. RESULTS: FFM(DXA) was highly related to FFM(Deu) in men (R2 = 0.93, P < 0.001) and women (R2 = 0.91, P < 0.001). On average, DXA resulted in higher FFM values than did Deu in COPD patients (3.4 kg; P < 0.001) and in healthy volunteers (2.1 kg; P < 0.001). Furthermore, the intramethod difference in FFM was higher in men than in women in the COPD group (P < 0.05) and in healthy volunteers (P < 0.001). BMD was lower in the COPD group than in the healthy, age-matched volunteers (P < 0.001). In 56% of the COPD patients, there were indications of bone mineral loss, defined as a BMD <1 SD of a matched reference population provided by the software. BMD was <2 SDs in 36% of the COPD patients. CONCLUSIONS: DXA appears to be a suitable alternative method to Deu for assessing body composition and is also of value in identifying bone mineral loss in COPD patients, and is therefore applicable in the clinical evaluation of these patients.

Absorptiometry, Photon↗
PubMed1998

Intense muscle uptake of gallium-67 in a patient with sarcoidosis.

Sarcoidosis has been associated with muscle involvement. In general, this involvement remains asymptomatic. The following case report demonstrates a patient with a 4-mo history of sarcoidosis who reported severe fatigue and slight muscular complaints at a regular checkup. Gallium scintigraphy indicated unexpected and unusually extensive muscular localizations of the disease. The latter findings were confirmed by examination of biopsy specimens. The importance of gallium scintigraphy lies in the possibility of wholebody screening for inflammation localizations, particularly when physical, laboratory, lung function and radiographic examinations fail to provide convincing evidence of active sarcoidosis. Furthermore, it can be helpful in the follow-up of the effect of supportive treatment.

Aged↗
PubMed1997

Energy expenditure and physical activity in relation to bone mineral density in women with anorexia nervosa.

OBJECTIVES: To assess sleeping metabolic rate (SMR), average daily metabolic rate (ADMR), and total bone mineral density (TBMD) in women with anorexia nervosa, and to evaluate the effect of daily physical activity on TBMD. DESIGN: We compared women with anorexia nervosa and controls using measurements on body composition, and energy expenditure. Relations between these measurements were investigated. SETTING: Daily living environments in The Netherlands, and body composition and energy expenditure laboratory of the Department of Human Biology. SUBJECTS: Twelve adult, non-hospitalized women with anorexia nervosa, and sixteen adult normal weight women. INTERVENTIONS: Average daily metabolic rate was measured with the doubly labeled water method and sleeping metabolic rate in a respiration chamber. TBMD was measured by dual energy X-ray absorptiometry, and percentage body fat was calculated combining the results from underwater weighing and deuterium dilution. RESULTS: TBMD was significantly lower in anorexia than in controls (0.989 +/- 0.081 vs 1.144 +/- 0.054 g/cm2). Also ADMR and SMR were reduced in anorexia. The physical activity index (PAI = ADMR/SMR) was not significantly different from PAI in controls. In anorexia, TBMD was related to the PAI (R2 = 0.35, P < 0.05). Finally, stepwise multiple regression revealed that PAI together with the study groups as dummy variables could explain 69% of the variation in TBMD. CONCLUSION: These findings show that in anorexia TBMD is reduced, but that nonetheless physical activity has a significant positive effect on bone density.

Absorptiometry, Photon↗
PubMed1997

The effect of a single rectal dose of cisapride on delayed gastric emptying.

BACKGROUND: Cisapride has an established prokinetic effect in patients with delayed gastric emptying. However, rectal administration of the drug might be preferred in patients with either dysphagia or nausea due to gastroparesis. AIM: To determine the effect of a single rectal dose of cisapride 60 mg on gastric emptying in patients with delayed gastric emptying. METHODS: Thirty-two patients (16 males, 16 females) with demonstrated delayed gastric emptying received a single dose of two suppositories containing either cisapride (2 x 30 mg) or placebo, according to a double-blind randomized crossover design. Three hours after administration of the suppositories, the patients received a radio-labelled test meal and radio-opaque markers for measurement of gastric emptying. RESULTS: The mean t1/2 after cisapride administration (76 min, 95% CI: 68-95) was significantly shorter (P = 0.005: n = 28, per-protocol analysis) than after placebo administration (104 min, 81-126). Four hours after ingestion of the meal significantly fewer radio-opaque markers remained in the stomach after cisapride than after placebo administration (P < 0.05). Mild to moderate adverse events, mainly involving the gastrointestinal tract, were reported in 10 patients (31%) after cisapride treatment and in four patients (13%) after placebo (N.S.: n = 32). CONCLUSION: A single suppository dose of cisapride 60 mg significantly accelerates gastric emptying of the solid phase of a meal and of radio-opaque markers in patients with previously demonstrated delayed gastric emptying.

Administration, Rectal↗
PubMed1997

In-111 octreotide imaging in staging of small cell lung cancer.

BACKGROUND: Small cell lung cancer (SCLC) tumors have neuroendocrine features. In vitro and in vivo studies have demonstrated that 50%-75% of SCLC tumors express receptors for somatostatin. This might enable in vivo localization of the primary tumor and its metastases by using scintigraphy with a radiolabeled somatostatin analogue, such as octreotide. PURPOSE AND METHODS: The efficacy of scanning with In-111 labeled octreotide (octreotide scan) was studied in the staging of SCLC patients and compared with the results of conventional staging (liver ECHO, bone scintigraphy, MRI of the brain, spine, and pelvis). Imaging was performed in 29 patients with histologically confirmed SCLC at 4, 24, and 48 hours after intravenous injection of 185 MBq In-111 octreotide. RESULTS: In 24 of 29 patients, the primary tumor was visualized. In these 24 patients, 26 metastases were demonstrated with conventional staging, of which only nine were visualized with octreotide scan. Octreotide scans showed two metastases in the brain that were not visualized by MRI. In the other five patients, five metastases were demonstrated with conventional staging. Only two of these were detected with octreotide scan. However, octreotide scan did show a further metastasis in the brain that was not visualized by MR imaging. CONCLUSION: Octreotide imaging has a limited use in the detection of SCLC metastases compared to conventional staging. It might have some specific value in the detection of brain involvement in patients with limited disease.

Carcinoma, Small Cell↗
PubMed1996

Lung and gastric uptake in bone scintigraphy of sarcoidosis.

We report on 99mTc-MDP uptake in lungs and stomach in a patient with hypercalcaemia and renal failure due to elevated 1,25(OH)2vitD3 because of sarcoidosis. Presently, this typical scan pattern has only been described in patients with malignancies, parathyroid adenoma and drug-induced vitamin D intoxication. We offer possible explanations for the findings in our patient.

Aged↗
PubMed1996

Baseline and postcaptopril renal blood flow measurements in hypertensives suspected of renal artery stenosis.

UNLABELLED: Renal blood flow (RBF) measurements using first-pass radionuclide angiography with DTPA, a glomerularly filtered agent, failed to show significant differences between normal and stenotic kidneys. Since MAG3 is an ideal agent for the study of RBF, this agent might be an attractive alternative tracer to detect differences in RBF. METHODS: An angiographically controlled prospective study was performed in 48 hypertensive patients, in whom a diagnosis of renovascular hypertension was suspected on clinical grounds. The study was done to determine whether RBF measurements using first-pass radionuclide angiography with 99mTc-MAG3 could be helpful in the diagnostic work-up of the patients. Additionally, the study was done before and after ACE-inhibition. RESULTS: On renal angiography, 29 patients showed to have normal renal arteries (50 patients had normal kidneys and 8 patients had small kidneys). Nineteen patients had renal artery stenosis (13 uni- and 6 bilateral disease). In the patients with normal kidneys, the mean value of RBF measurements ranged from 10.5% to 10.9% of cardiac output. Only small stenotic and small kidneys with normal renal arteries showed a significant reduced baseline RBF as compared with normal kidneys (both p < 0.05); this difference disappeared after ACE-inhibition only for the small kidneys with normal renal arteries. In patients with stenosed kidneys, RBF tended to be reduced both at baseline and after captopril, but the differences with normal kidneys were not statistically significant. After ACE-inhibition RBF increased in the majority of kidneys, but postcaptopril RBF data did not differ significantly from those at baseline. CONCLUSION: RBF measurements using first-pass radionuclide angiography with 99mTc-MAG3, either before or after ACE-inhibition, cannot reliably discriminate between patients with essential hypertension and patients with renal artery stenosis.

Captopril↗
PubMed1995

Beta-adrenergic stimulation and abdominal subcutaneous fat blood flow in lean, obese, and reduced-obese subjects.

The present study was designed to investigate whether the beta-adrenergically mediated blood flow response of abdominal subcutaneous adipose tissue (per unit adipose tissue weight) was altered in obesity and to study the effect of weight reduction on this response. Body composition (underwater weighing) and fat blood flow were determined in a group of lean (n = 9; % body fat, 11.6 +/- 3.9) and obese (n = 9; % body fat, 28.3 +/- 1.8) subjects. In seven obese subjects, measurements were also performed after a 4-week period of weight reduction induced by a very-low calorie diet (% body fat after diet 23.4 +/- 3.3). After an overnight fast, abdominal subcutaneous fat blood flow was determined by the 133xenon washout technique during a 30-minute period of supine rest and during 30-minute periods of infusion of the beta-agonist isoprenaline (ISO) with and without simultaneous infusion of the beta 1-blocker atenolol (AT). Basal abdominal fat blood flow was significantly higher in lean as compared with obese subjects, whereas weight reduction significantly increased basal fat blood flow (obese v reduced-obese, P < .05). There was a significant increase in abdominal fat blood flow as a result of ISO infusion in lean and obese subjects before and after weight reduction. During ISO+AT infusion, abdominal fat blood flow was still significantly increased as compared with control values in lean and obese subjects. The increase in blood flow during ISO was significantly higher in lean subjects than in obese subjects, whereas the ISO+AT-induced blood flow response was comparable.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdominal Muscles↗
PubMed1994

Total forearm blood flow as an indicator of skeletal muscle blood flow: effect of subcutaneous adipose tissue blood flow.

1. In studying forearm skeletal muscle substrate exchange, an often applied method for estimating skeletal muscle blood flow is strain gauge plethysmography. A disadvantage of this method is that it only measures total blood flow through a segment of forearm and not the flow through the individual parts such as skin, adipose tissue and muscle. 2. In the present study the contribution of forearm subcutaneous adipose tissue blood flow to total forearm blood flow was evaluated in lean (% body fat 17.0 +/- 2.2) and obese males (% body fat 30.9 +/- 1.6) during rest and during infusion of the non-selective beta-agonist isoprenaline. Measurements were obtained of body composition (hydrostatic weighing), forearm composition (magnetic resonance imaging) and of total forearm (venous occlusion plethysmography), skin (skin blood flow, laser Doppler), and subcutaneous adipose tissue blood flow (133Xe washout technique). 3. The absolute forearm area and the relative amount of fat (% of forearm area) were significantly higher in obese as compared to lean subjects, whereas the relative amounts of muscle and skin were similar. 4. During rest, the percentage contribution of adipose tissue blood flow to total forearm blood flow was significantly higher in lean compared with obese subjects (19 vs 12%, P < 0.05), whereas there were no differences in percentage contribution between both groups during isoprenaline infusion (10 vs 13%). Furthermore, the contribution of adipose tissue blood flow to total forearm blood flow was significantly lower during isoprenaline infusion than during rest in lean subjects (P < 0.05), whereas in the obese this value was similar during rest and during isoprenaline infusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1994

Measurement of anterior-posterior diameter of inferior vena cava by ultrasonography: a new non-invasive method to assess acute changes in vascular filling state.

OBJECTIVE: The aim was to determine whether measurement of the anterior-posterior diameter of the inferior vena cava (IVC) by ultrasonography, before and during deep inspiration, allows indirect information on baseline blood volume and changes in vascular filling state to be obtained in healthy subjects. METHODS: Blood volume was measured in 12 volunteers by a standard radioactive isotope method. The IVC dimensions were measured by ultrasound in various positions. In addition, in 10 male subjects the effect on the IVC dimensions of volume loading was evaluated by rapid infusion of plasma expander. During and immediately following volume loading, the IVC dimensions and blood volume were remeasured. RESULTS: Neither the baseline IVC diameters nor any combination of these variables correlated with the concomitant blood volume. Volume loading increased the anterior-posterior IVC dimensions linearly, the largest increase being observed with the maximum IVC diameter and the subject in supine position. CONCLUSIONS: It follows that ultrasonic IVC indices cannot be used as accurate indirect estimate of baseline blood volume, but provide reliable information on acute changes of the subjects' vascular filling state.

Adult↗
PubMed1994

Beta-adrenergic stimulation of energy expenditure and forearm skeletal muscle metabolism in lean and obese men.

The effect of beta-adrenergic stimulation on whole body energy expenditure and forearm skeletal muscle metabolism was investigated in lean and obese men. Whole body energy expenditure was determined during rest and during intravenous infusion of increasing doses of the nonselective beta-agonist isoprenaline (Iso). Forearm skeletal muscle metabolism was investigated with Iso infusion with and without simultaneous infusion of the beta 1-blocker atenolol (AT) by measuring skeletal muscle blood flow (SMBF) and arteriovenous concentration differences of various metabolites. The changes in SMBF were estimated from forearm total (venous occlusion plethysmography), skin (laser doppler), and fat tissue blood flow (133Xe washout). The increase in whole body energy expenditure with Iso was similar in lean and obese subjects. With Iso, the rise in arterial or arterialized glycerol and nonesterified fatty acids (NEFA) was lower in obese than lean subjects, which may reflect a lower beta-adrenergically mediated lipolysis in obesity. During infusion of increasing doses of Iso, the respiratory exchange ratio decreased significantly in lean subjects but not in the obese subjects, which indicates a more pronounced increase in fat oxidation in lean subjects. This is confirmed by the data on skeletal muscle metabolism, where NEFA uptake was increased in lean subjects, whereas the obese subjects showed a tendency toward an increased glucose uptake and a significantly increased lactate release. With Iso plus AT (mainly beta 2-adrenergic stimulation), both groups showed an increased skeletal muscle lactate release. In conclusion, although the thermogenic response to Iso was similar in lean and obese subjects, the utilization of fat seems to be impaired in obesity.

Adrenergic beta-Agonists↗
PubMed1994

beta-Adrenergic stimulation of skeletal muscle metabolism in relation to weight reduction in obese men.

In a companion study [Blaak, E.E., M.A. van Baak, G.J. Kemerink, M.T.W. Pakbiers, G.A.K. Heidendal, and W.H.M. Saris. Am. J. Physiol. 267 (Endocrinol. Metab. 30): E306-E315, 1994.], we found that during infusion of the nonselective beta-agonist isoprenaline (Iso), obese males had a lowered Iso-induced rise in arterial glycerol and nonesterified fatty acids (NEFA) and a lowered muscle NEFA oxidation. The present study was intended to investigate whether a period of weight reduction would alter this impaired fat utilization in obese males. Before and after a 5-wk diet intervention (very low calorie diet) whole body energy expenditure was determined during rest and during intravenous infusion of increasing doses of Iso. In addition, forearm muscle metabolism was investigated with Iso infusion with and without simultaneous infusion of the beta 1-blocker atenolol (AT) by measuring skeletal muscle blood flow and arteriovenous concentration differences of various metabolites across muscle. The Iso-induced whole body thermogenesis tended to increase as a result of weight loss when this response was related to the plasma Iso concentration (P = 0.09), whereas both before and after diet there were no changes in the respiratory exchange ratio during Iso infusion. The increases in arterial NEFA and glycerol concentrations as a result of Iso infusion were not significantly different before and after weight reduction. In addition, muscle NEFA uptake did not change as a result of Iso or Iso plus AT infusion both before and after diet, whereas muscle glucose uptake and lactate release tended to be more pronounced after weight reduction.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Agonists↗
PubMed1992

Scintigraphic diagnosis of bile leakage after laparoscopic cholecystectomy. A prospective study.

To assess the role of Tc-99m IDA cholescintigraphy in diagnosing bile leakage and bile obstruction after laparoscopic cholecystectomy, 51 studies were performed in 51 patients on the first postoperative day. Two different radioactive bile acid analogs were used, Tc-99m HIDA and Tc-99m trimethylbromo IDA. Scintigraphic findings were correlated with the clinical conditions. Results of seven out of 51 cholescintigrams were abnormal, showing accumulations of activity in the right paracolic gutter. Of these seven patients, only three had clinical symptoms consisting of more than normal postoperative abdominal pain and peritoneal irritation. The other four patients had minimal abnormal accumulation in the right paracolic gutter and showed no clinical signs postoperatively. Complete common bile duct obstruction or other bile duct-related complications, except for bile leakage, were not observed. Cholescintigraphy is feasible for the early detection of bile leakage and bile flow obstruction after laparoscopic cholecystectomy in patients with increased postoperative abdominal discomfort.

Bile Duct Diseases↗
PubMed1991

Macroporous calcium phosphate ceramics for bone substitution: a tracer study on biodegradation with 45Ca tracer.

The value of artificial materials in bone replacement depends highly on their biocompatibility and biostability. Porous calcium phosphate ceramics have a good compatibility with natural bone. To study the biodegradation process of calcium phosphate bioceramics, labelled [45Ca]-beta-whitlockite and [45Ca]-hydroxyapatite were implanted in the femurs of dogs. The effects accompanying the ingrowth of new bone into the pores of these bioceramics and its replacement by natural bone were investigated. In vivo degradation of the implant material by biochemical dissolution processes was observed. The beta-whitlockite implants showed a conspicuous decrease in radioactive calcium, in contrast to the hydroxyapatite implants. 45Ca was absent in adjacent bones and locally newly formed bone in both beta-whitlockite and hydroxyapatite suggesting a restricted availability of the 45Ca liberated in these processes. Indications of minor mechanical degradation of the materials were also found; in the lymph nodes a very small amount of 45Ca with a high specific activity was detectable. Urine, blood or faeces contained no detectable amounts of 45Ca activity.

Animals↗