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W Estelberger

Publications and source records attributed to W Estelberger.

28 records · Page 2Linked to original sources
PubMed1991

Sigma S, a measure of reactive sulfur groups of immunoglobulin G, is a sensitive tumor marker discriminating different stages of breast cancer.

Sigma S is a measure of the disulfide bonds and free thiol groups of serum immunoglobulin (Ig) G, as determined by the reaction with dithionitrobenzoate. Significant decreases of sigma S previously were detected in malignant compared with benign diseases of various organs. This study shows the application of sigma S for the diagnosis of breast cancer. The following results were obtained. First, 132 patients with benign breast diseases showed a sigma S of 1.48 +/- 0.29 (standard deviation) per mole IgG; this was not different from 1.51 +/- 0.36 found in 182 controls. In contrast, IgG from 198 patients with primary breast carcinoma of all four stages (tumor-node-metastasis system) gave a sigma S of 1.22 +/- 0.29, a significant (P less than 0.0001) decrease of sigma S from benign to malignant breast disease. Second, sigma S values of single Stages I, II, III, and IV, were 1.27 (n = 59), 1.23 (n = 83), 1.19 (n = 35), and 1.10 (n = 21), respectively, each significantly different from sigma S in benign disease and showing a decreasing trend with increasing tumor progress. Differences were significant between Stages I and IV (P less than 0.025) and II and IV (P less than 0.05). Third, 63% of Stage I breast carcinoma patients had sigma S values below a critical threshold of 1.38. This serum positivity rose to 90% in Stage IV. These values exceeded those reported with other tumor markers. The overall power of sigma S to distinguish between benign and malignant breast disease had a specificity of 61% and a sensitivity of 78%. Early stages (I and II) of breast cancer could be distinguished from benign diseases with 64% specificity and 69% sensitivity. Advanced Stage IV could be discriminated from early Stages I and II with 55% specificity and 71% sensitivity. Thus, the analysis of sigma S may significantly contribute to the surveillance of patients with breast cancer.

Adult↗
PubMed1989

Labile disulfide bonds and free thiol groups in human IgG. V. Association of postoperative mean 'sigma S' course and tumor recurrence in ovarian cancer.

Sigma S comprises both free thiol groups and labile S-S-bonds of the total IgG that react with dithionitrobenzoate. Previous investigations have shown that this parameter was significantly decreased in malignant diseases of various organ systems as compared with benign disorders of the respective organs. The present study on patients with ovarian cancer investigated whether a significant correlation exists between the post-operative course of sigma S and the clinical evidence. For this purpose, on the basis of former results, a value of sigma S of 1.25 was determined as a criterion between malignant and benign ovarian diseases. For each investigated case, the post-operative temporal average of sigma S was calculated (sigma S) and a value of 1.25 was used as discriminating threshold. A four-fold table was set up containing the frequencies of tumor recurrences and tumor free cases with sigma S less or greater than 1.25. In a total of 40 patients of ovarian cancer an association between sigma S less than 1.25 and increased frequency of recurrences was confirmed, with a probability of error of 1%. The total predictive value of the sigma S level was about 70% and is herewith comparable to the leading tumor marker CA 125 in ovarian cancer.

Biomarkers, Tumor↗
PubMed1989

Relationship between generation and plasma concentration of anorganic phosphorus. In vivo studies on dialysis patients and in vitro studies on erythrocytes.

The plasma concentration of inorganic phosphorus (Pi) was determined before, during and after hemodialysis in 28 patients with chronic renal failure. Pi plasma concentration decreased rapidly when hemodialysis was started but did not fall below normal levels during continued dialysis. These changes of Pi concentration were fitted to a model of Pi kinetics in which Pi delivery to plasma is a nonlinear function of the extracellular Pi concentration. In separate in vitro studies, erythrocytes from six subjects with normal renal function and from 14 patients with chronic renal failure were incubated in homologous plasma with various amounts of Pi added. All other factors known to affect the Pi shift between intra- and extracellular fluid compartments (pH, calcium concentration) were kept constant. The relation between Pi concentration in plasma used for incubation and in red cells after 1h incubation suggested a mechanism in which a high plasma concentration results in movement of Pi into red cells where Pi is stored most probably in glucose esters. At low Pi plasma concentration Pi is delivered to plasma at a rate which cannot be explained solely by passive movement of intracellular Pi to plasma but requires additional generation from intracellular storage forms. The generation and delivery of Pi in patients and in their erythrocytes indicate a simple cell-mediated Pi homeostasis counter-acting abnormal fluctuations of plasma Pi.

Adolescent↗
PubMed1988

Quantitative characterization of diet effects on glucose tolerance in rabbits.

Normal, atherogenic and butter-enriched diets were given to three groups of rabbits during six months. The effects of the three forms of diet after six months were examined with the intravenous glucose tolerance test, which was evaluated by computer-aided model-fitting and parameter identification. Long-term effects are reflected in parameters such as pancreas sensitivity and the glucose utilization rate constant as a measure of peripheral insulin sensitivity. In these terms, the atherogenic diet caused a diminution of both pancreatic and peripheral sensitivity, whereas the butter-enriched diet led to an increase in glucose utilization and a decrease in pancreatic sensitivity relative to the system parameters of the normally fed control animals. Related to the findings about metabolic regulation are indications for an endocrinological approach to the problems of cholesterogenesis and atheroma formation.

Animals↗
PubMed1981

System identification of the control of gluconeogenesis in the intact organism under conditions of long-term stress.

In this article a system-theoretic approach to hormonal control of gluconeogenesis as observed in the intact organism under hypoglycemia and hypoxia is attempted. Under such conditions the secretion of the stress hormone corticosterone by the adrenal cortex is effected by neural control centres inducing the synthesis of gluconeogenetic enzymes which catalyze the production of glucose from amino acids originating from body tissues. The time courses of the hormonal, enzymatic and metabolic quantities measured are evaluated in the framework of a model in the form of a system of differential equations, the parameters of which are determined by a numerical search procedure.

Animals↗
PubMed1976

Spectral analysis of spontaneous contractions of the isolated portal vein of rats.

The spontaneous contractions of segments of rat portal veins have been examined in vitro under isotonic and isometric conditions. The power density spectra of recorded time series lasting 10-60 min were calculated. The spectra usually consist of harmonic frequency components. Only during shorter periods of analysis (10 min time series) we sometimes found additional non-harmonic components. All frequency components are proportionally shifted by changes of the bath temperature according to an average Q10 of 2.0. Increase of the load decreases the frequency of the contractons. The results of the spectral analysi, indicating a preponderance of a single source of periodicity, were supported by direct evidence of a pacemaker region. By recording contractions after systematic dissections of the portal vein segment, we found that spontaneous activity is generated at the central end of the segment.

Animals↗
PubMedDate not supplied

Single-injection inulin clearance--a simple method for measuring glomerular filtration rate in dogs.

The glomerular filtration rates (GFR) of 93 dogs of different breeds with a broad range of bodyweight were determined using an inulin single-injection method. Fifty-two dogs were used as controls, 21 dogs had suspected renal disease but serum creatinine in the normal range, and 20 dogs had elevated serum creatinine levels and a low urine specific gravity due to renal disease. Inulin was injected intravenously at a dosage of 100 mg kg(-1) bodyweight or 3000 mg m(-2) body surface. Blood samples were taken before and three, 20, 40, 80 and 120 minutes after injection. The total clearance was calculated from the decrease in the serum concentration of inulin using a two-compartment model. The range of GFR values was 83.5-144.3 ml min(-1) m(-2) in control dogs, 60.2-96.7 ml min(-1) m(-2) in dogs with suspected renal disease, 50.0-76.2 ml min(-1) m(-2) in dogs with suspected renal disease and polyuria/polydipsia, and 16.3-63.0 ml min(-1) m(-2) in dogs with azotaemic renal disease. The study indicates that single-injection inulin clearance is a cheap and simple tool for GFR measurements in small animal practice.

Animals↗