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J Rendl

Publications and source records attributed to J Rendl.

29 records · Page 2Linked to original sources
PubMed1994

Urinary iodide determined by paired-ion reversed-phase HPLC with electrochemical detection.

We propose an automated method for the routine analysis of urinary iodide, using paired-ion reversed-phase HPLC with electrochemical detection and a silver working electrode. Assay conditions include a flow rate of 1.0 mL/min and an operating potential of 0.10 V. The retention time for iodide is 5.4 min. Sample preparation can be semiautomated by use of a reduced-pressure manifold. The detection threshold (signal-to-noise ratio of 3) was 2 pmol, corresponding to 0.04 mumol/L. The within-run precision (CV) for a pooled urine sample was 3.9% at 452 nmol/L iodide. The average recovery of added iodine was 94%. For comparison with a colorimetric method, we measured 177 random (untimed) urine samples by both HPLC (y) and a Technicon AutoAnalyzer acid digestion method (x). After removal of organically bound iodine, the results for unbound urinary iodide determined by the two methods were nearly identical (r = 0.99; y = -0.03 + 1.00x; Sy/x = 0.12 mumol/L). Comparison of total urinary iodine measured by the Technicon AutoAnalyzer with unbound urinary iodide determined by HPLC also showed a high correlation (r = 0.96; y = -0.03 + 0.78x; Sy/x = 0.23 mumol/L), because iodine is excreted in urine mainly as iodide. We conclude that iodine in urine can be accurately determined by the more convenient HPLC assay.

Autoanalysis↗
PubMed1993

[Unilateral autonomous aldosterone production in hyperaldosteronism suppressible by dexamethasone].

A 21-year-old woman with weight loss, palpitations and facial flush was found to have hypertension (up to 200/130 mm Hg) and mild hyperkalaemia (3.4 mmol/l). Extensive diagnostic tests revealed hyperaldosteronism with contrast storing in the right adrenal gland on scintigraphy after injection of dexamethasone (2 mg daily for one week). The hyperaldosteronism could not be suppressed by dexamethasone. Analysis of venous blood separately from each side pointed to aldosterone production in the right adrenal (right renal vein: 80 ng/dl, drainage area of the right adrenal vein: 114 ng/dl, left renal vein: too low to measure). The right adrenal gland was removed. No adenoma was found histologically. After the operation the aldosterone level was reduced and the blood pressure transiently fell. But both had risen again after 3 months. Renewed tests revealed dexamethasone-remediable hyperaldosteronism. On treatment with hydrocortisone (15-5-5 mg) and 50 mg metoprolol the patient became normotensive without any other medication.

Adrenal Cortex Hormones↗
PubMed1992

[Is a TSH screening for the diagnosis or exclusion of functional thyroid autonomy meaningful?].

A normal baseline TSH serum concentration is accepted as excluding thyroid dysfunction. The present study examined the usefulness of that concentration as a screening test for functional autonomy. 310 patients were retrospectively examined. They were all clinically euthyroid and had normal peripheral thyroid hormone concentrations. The positive predictive value for the confirmation of autonomy was 55.5%, the negative predictive value for the exclusion of autonomy 87.7%, using 0.5 mU/l as a lower limit. The probability for the presence of thyroid autonomy in patients with a TSH serum concentration below 0.3 mU/l was 72.5%.

Female↗
PubMed1991

Imaging pattern of radiolabelled lymphokine-activated killer cells in patients with metastatic malignant melanoma.

In patients with metastatic malignant melanoma the distribution patterns of radiolabelled lymphokine-activated killer (LAK) cells were investigated. Peripheral mononuclear cells (PMC) were isolated from six patients. LAK cells were generated by culturing PMC in complete medium containing 1000 U interleukin (IL)-2/ml and labelled with indium 111 before retransfer. We obtained scans at 2.5, 24, 48 or 96 h after injection with a high resolution gamma-camera. Intravenously injected LAK cells distributed to the lungs, liver, spleen and bone marrow. External tumour detection of known lymph node and bone metastases was successful in four. It failed in one patient with a solitary lung metastasis and in another patient with subcutaneous metastases. Our results suggest that LAK cells show tumour homing, providing a direct interaction between tumour and cytotoxic cells. We conclude that PMC seem to retain their ability to migrate after IL-2 stimulation and 111In-labeling. This technique may be helpful for kinetics studies or external detection of metastases in patients with malignant melanoma.

Adult↗
PubMedDate not supplied

The use of recombinant human TSH in a patient with metastatic follicular carcinoma and insufficient endogenous TSH production.

We present a case of a patient suffering from metastatic differentiated thyroid carcinoma (DTC) and insufficient endogenous TSH production suspicious of secondary hypothyroidism. The use of recombinant human TSH (rhTSH) enabled us to administer a therapeutic activity of radioactive iodine (RAI) under maximal TSH-stimulation, achieving a marked decrease in thyroglobulin accompanied by a clinical improvement.

Adenocarcinoma, Follicular↗
PubMedDate not supplied

[Significance of 2 different bone density measurement methods in the assessment of mineral content of the peripheral and axial skeleton].

Between May 1990 and February 1991 we enrolled 212 patients of 410 referred to our clinic for bone mass evaluation according to different diagnosis or therapeutic procedures. These patients were divided into 7 groups. The question had to be answered, which method of measurement and which skeletal site would give better information about the influence of the diseases of therapeutic procedures. We measured the areal mineral density of the lumbar spine with dual x-ray absorptiometry (DEXA) and the mineral content of the total and trabecular bone mass of a cross-sectional slice at the distal radius with peripheral quantitative computed tomography (pQCT). The results were statistically analysed. We calculated the percentage deviation from young normals. Trabecular mineral content showed the greatest difference (18% to 44%), compared to the healthy reference group, corresponding to the known higher turnover of this bone compartment. In contrast, the difference of the areal density of the lumbar spine was found to be lowest (4% to 27%). In order to compare the methods objectively, we additionally calculated a ROC-analysis of two postmenopausal groups (51 healthy, 46 osteoporotic) to demonstrate the diagnostic validity. The validity proved to be substantially better when purely trabecular bone at the distal radius was measured. The ROC-curves showed a sensitivity of 84% for radial trabecular bone on a specificity level of 90%, whereas the lumbar spine values presented with a sensitivity of only 68%.

Absorptiometry, Photon↗
PubMedDate not supplied

[Iodine concentration in the breast milk of mothers of premature infants].

UNLABELLED: In this prospective study the longitudinal iodine concentration was compared in breast milk of preterm infants mothers, with and without iodine supplementation. 195 samples of breast milk from 60 mothers were analyzed by HPLC longitudinally. RESULTS: Mothers who take additional iodine (200 micrograms/d) had significant higher mean iodine concentrations in breast milk (mean: 7.6 +/- 6.3 micrograms/dl) than mothers without additional iodine supply (mean: 5.5 +/- 5.8 micrograms/dl/p < 0.02). Nontreated mothers showed significantly more breast milk iodine concentrations below the recommended minimum concentration of 5 micrograms/dl (64%, n = 84) than treated mothers (40%, n = 25/p = 0.0016). Mean iodine intake in preterm infants of treated mothers was higher (11.9 micrograms l/kg) than in preterm infants of nontreated mothers (7.9 micrograms l/kg). DISCUSSION: The measured iodine concentrations in breast milk of preterm infants mothers markedly varied inter- and intraindividual. The variations might be explained by irregular daily iodine intake and a dilution effect by increasing breast milk volumes. CONCLUSIONS: Iodine supplementation of lactating mothers leads to elevated iodine content of their breast milk. The recommended intake of iodine for both newborns (15 micrograms l/kg) and preterm infants (30 micrograms l/kg) was not reached in the breast fed preterm infants in both groups of our study.

Adult↗