Infrared spectroscopy in clinical chemistry, using chemometric calibration techniques

The scope of this thesis was to further develop the assays of fecal fat and urinary calculi. The developments mainly consisted of the investigation of the applicability of new infrared spectroscopic methods and the application of chemometrical methods for quantification. Furthermore, we gave information about the pathophysiology background of our studies. The quality of some traditional clinical chemical methods needs improvement. Therefore, studies were undertaken to develop new methods for the determination of fecal fat and the composition of urinary calculi. For these new methods, infrared spectroscopy has been used for the determination of the components of interest. ... Zie: Summary

Fallfilmverdampfer und Verfahren zu dessen Betrieb und Verwendung

Die Erfindung betrifft einen Fallfilmverdampfer (1) mit zumindest einer Berieselungseinrichtung (11), zumindest einer darunter angeordneten Verdampferstruktur (12) und zumindest einem Sumpf (13), wobei die Verdampferstruktur (12) zumindest eine Heizfläche (121) aufweist, welche mit einer porösen Beschichtung (2) versehen ist, wobei die poröse Beschichtung (2) zumindest teilweise so ausgestaltet ist, dass ein mittlerer Porendurchmesser r der Poren (25) der ersten porösen Beschichtung (2) und deren größte zusammenhängende senkrechte Ausdehnung h in folgendem Zusammenhang stehen:wobei σ die Oberflächenspannung und θ den Kontaktwinkel bezeichnen, ρ die Dichte der Flüssigkeit angibt, g die Schwerebeschleunigung darstellt und F den Umlenkfaktor bezeichnet, welcher zwischen etwa 0,1 und etwa 1 oder zwischen etwa 0,2 und etwa 1 gewählt ist. Weiterhin betrifft die Erfindung ein Verfahren zur Verdampfung einer Flüssigkeit und eine Verwendung des Fallfilmverdampfers

Reference Values for Aldosterone-Renin Ratios in Normotensive Individuals and Effect of Changes in Dietary Sodium Consumption

BACKGROUND: Determination of the aldosterone-to-renin ratio (ARR) in blood is the preferred screening test for primary aldosteronism. Renin can be measured as the plasma renin activity (PRA) or the plasma renin concentration (PRC). Consequently, the ARR can be measured either based on the PRA (ARR(pra)) or based on the PRC (ARR(prc)). In contrast with the ARR(pra), the data on reference values for the ARR(prc) are limited. Moreover, whether the ARR(pra) or ARR(prc) is affected by variations in salt intake is unknown. METHODS: We measured the PRA, the PRC, and serum aldosterone in 100 normotensive individuals between 20 and 70 years of age before and after a 3-day oral sodium-loading test (SLT). Participants were stratified according to age and sex. Data are presented as the median and interquartile range (IQR). RESULTS: Urinary sodium excretion after the SLT was >= 200 mmol/24 h in all participants. Serum aldosterone, PRA, and PRC values were significantly reduced after the SLT. PRC and PRA results were highly correlated [Spearman rank correlation r(s) = 0.80 and 0.74 before and after SLT, respectively; P <0.001 for both]. The central 95% reference intervals for ARR(pra) before and after SLT were 0.07-1.45 h(-1) and 0.06-1.84 h(-1), respectively. The corresponding reference intervals for ARR(prc) were 4.1-81.3 pmol/ng and 3.9-74.8 pmol/ng. The median ARR(prc) decreased after the SLT from 19.5 pmol/ng (IQR, 13.0-29.4 pmol/ng) to 18.6 pmol/ng (IQR, 9.4-27.1 pmol/ng) (P = 0.005), whereas the median ARR(pra) did not change (P = 0.12). Both the ARR(prc) and ARR(pra) at baseline were higher in women than in men, whereas no sex difference was observed after sodium loading. CONCLUSIONS: We present reference values for the ARR(prc) for healthy individuals. The ARR is affected to a variable degree by sex and sodium intake

Serum Tryptophan and Kynurenine Concentrations as Parameters for Indoleamine 2,3-Dioxygenase Activity in Patients With Endometrial, Ovarian, and Vulvar Cancer

Objective: Indoleamine 2,3-dioxygenase (IDO) suppresses the function of T-lymphocytes and is involved in immune escape of cancers. Indoleamine 2,3-dioxygenase catalyzes the initial rate-limiting step in the degradation of the essential amino acid tryptophan. In this study, we investigated cancer-induced IDO activity in sera of endometrial, ovarian, and vulvar cancer patients. Methods: Concentrations of tryptophan and kynurenine were determined in pretreatment serum samples of patients with endometrial (n = 41), ovarian (n = 28), and vulvar cancer (n = 40) and compared to 19 healthy female controls. In serum of a subgroup of endometrial (n = 22), ovarian (n = 21), and vulvar (n = 21) cancer patients, tryptophan, kynurenine, and the kynurenine-to-tryptophan ratio (kyn/trp) were determined at different time points: preoperative, at clinical remission, and at the time of diagnosis of recurrent disease. Analyses were performed by an automated online solid-phase extraction-liquid chromatographic-tandem mass spectrometric method. Indoleamine 2,3-dioxygenase activity was estimated by calculating the kyn/trp ratio. Results: Kynurenine concentrations and the kyn/trp ratio were higher in preoperative serum of endometrial, ovarian, and vulvar cancer patients compared to controls (all: P <0.001). Preoperative serum of ovarian cancer patients contained higher kynurenine concentrations (median, 2.53 mu M; interquartile range [IQR], 1.72-4.29 mu M) and a higher kyn/trp ratio (median, 39.3 mu mol/mmol; IQR, 26.5-61.7 mu mol/mmol) compared to serum collected at clinical remission (median, 2.02 mu M; IQR, 1.68-2.72 mu M, P = 0.035; and median, 29.9 mu mol/mmol; IQR, 23.4-38.9 mu mol/mmol, P = 0.005, respectively). Conclusions: Patients with endometrial, ovarian, and vulvar cancer have increased tryptophan degradation compared to controls resulting in higher serum kynurenine concentrations and a higher kyn/trp ratio. Our results suggest that IDO-induced immune escape may play an important role in these gynecologic cancers