Entwicklung und Anwendung eines 3H-Androstendion-Radioimmunoassay für endokrinologische Untersuchungen

Ein ³radioimmunoassay (RIA) for precise and reliable determination of androstenedione (androst-4-ene-S,17-dione, AD) in endocrinological investigations has been developed. Specific antisera were obtained from rabbits following immunization with the bovine serum albumine conjugate of AD-3- (O-carboxymethyl)oxime. The sensitivity of the method was found to be 18fmol AD per assay tube. The method described has proved to be suitable for determinations of AD values in blood plasma and follicular fluids of cattle and swines.     

Optimization of Total Thyroxine Radioimmunoassay in Unextracted Serum by Dextran Charcoal

Specific method for accurate radioimmunoassay of free and total thyroxine in un-extracted serum has been developed. The method is used for estimation of either free thyroxine (T₄) or total T₄ by inhibition of the binding sites of T₄ to protein using TCA/NaOH mixture. The antibodies used in this study were obtained from Mallinkrodt. The separation technique used in our modification is that of dextran charcoal, this is to absorb the free fractions on charcoal.

The kinetics of antibody antigen combination, the parameters of the experiment like; charcoal concentration, antibody dilution, temp., time of incubation and radioactivity concentration were, studied to optimize the standard curve and the sensitivity of T₄RIA.

Serum samples of different thyroid cases were investigated for determination of free and total T₄ concentration to get the levels for each group of which 50 normals, 57 hyperthyroidism and 21 hypothyroidism in comparison with the classical tests of thyroid functions. Also sensitivity and variance coefficient has been carried out in comparison with other T₄RIA techniques.     

Flow Injection and Related Techniques in Blood Studies for Clinical Screening and Analysis: A Review

Blood studies for clinical screening/analysis are geared toward point of care testing. Flow based techniques have expanded their applications with unique approaches that may be adaptable for use as alternative disease screening/diagnosis. Many newly developed systems for solution based chemical analysis can be easily adapted for use with plasma and serum. However, cell and intracellular analyses are different. Blood cell analyses require a particular way of sample introduction and detection. This review emphasizes the applications of flow based techniques, especially those that were coupled with FI/SI, in clinical studies through analysis of red blood cells and their intracellular substances.     

Blood Levels of Hexavalent Chromium in Rats. “In Vitro” and “In Vivo” Experiments

Abstract

For the Cr(VI) selective separation from biological materials we have developed a highly rapid extraction-separation method with liquid anion exchanger as Amberlite LA-1 or LA-2. The analytical determination of Cr(VI) in organic phase was carried out using electrothermal atomic absorption spectroscopy (ETA-AAS).

After i.v. administration of 0.5 and 2.5mg/kg b.w. of K₂Cr₂O₇ in male Wistar rats the biological samples, collected at different times, were immediately analyzed. Cr(VI) was not detected in whole blood one minute after administration of the lower dose. In blood of rats receiving higher dose an incomplete reduction of Cr(VI) was observed.

Such data demonstrate a highly rapid but limited metabolic capacity of hematic compartment to reduce Cr(VI) to trivalent status.

These results obtained with a new and specific analytical method, confirmed a trigger role of red cells in Cr(VI) metabolism.

“In vitro” incubation of K₂Cr₂O₇ (4 μM) with rat erythrocytes or plasma at 37°C showed a rapid reduction of Cr(VI) in red cells while plasma samples demonstrated a limited reductive power.     

Ketamine and norketamine stability in whole blood at ambient and 4°C conditions

A study was implemented to describe the pharmacokinetics (PK) of ketamine (K) and its metabolite norketamine (NK) in critically ill adults. Conducting studies in these subjects is hindered by the immediate need to process and freeze samples obtained in a busy intensive care setting. The ability to store unprocessed samples at room temperature for an extended time period would overcome this barrier. Stability and blood to plasma partitioning of K and NK were investigated in whole blood for up to 120 h at room temperature and 4°C. Whole blood was spiked with K and NK (1000 ng/mL each). Blood samples were aliquoted at different time points (0–120 h), extracted and analyzed using a validated high‐performance liquid chromatography tandem mass spectrometry assay. The study demonstrated the stability of both K and NK in whole blood up to 120 h. These in vitro studies suggest that the concentrations of K and NK measured in the PK samples are reliable. The established stability results were successfully employed to investigate K and NK pharmacology studies in critically ill adults.     

Effects of Tao‐Hong‐Si‐Wu decoction on acute blood stasis in rats based on a LC‐Q/TOF‐MS metabolomics and network approach

A novel approach using metabolomics coupled with a metabolic network was used to investigate the effects of Tao‐Hong‐Si‐Wu decoction (THSWD) on the rat model of acute blood stasis syndrome. Acute blood stasis syndrome was induced by placing the rats in ice‐cold water following two injections with epinephrine. The hemorheological indicators [whole blood viscosity (WBV) and plasma viscosity (PV)] and the blood coagulation indicators [thrombin time (TT), prothrombin time (PT), activated partial thromboplastin time (APTT) and fibrinogen (FIB)] were detected. The nonparametric univariate method and multivariate statistical analysis were performed for determining the potential biomarkers. A correlation map was structured between biochemical indicators and hub metabolites to explain the effects mechanism of THSWD. After the administration of THSWD, the levels of WBV, PV, TT, APTT and FIB returned to levels observed in the control group. According to metabolomics coupled with metabolic network analysis, the intervention of THSWD in rats with acute blood stasis syndrome induced substantial and characteristic changes in their metabolic profiles. Fifteen metabolites were screened, which mainly involved 10 pathways and five hub metabolites, namely, l ‐glutamate, l ‐phenylalanine, N‐acylsphingosine, arachidonic acid and phosphatidate. The biochemical indicators and hub metabolites could be adjusted to close to normal levels by THSWD. Therefore, combining metabolomics and metabolic network helped to evaluate the effects of THSWD on acute blood stasis.     

青春期多囊卵巢综合征患者代谢综合征的患病特点

目的探索青春期多囊卵巢综合征（PCOS）患者代谢综合征（MS）患病特点。方法收集80例青春期PCOS患者MS患病率与肥胖、年龄、胰岛素抵抗和ApoB/ApoA1比值的关系。结果青春期PCOS患者MS患病率为12.50%，其中非肥胖患者MS和前代谢综合征阶段（pre-MS）患病率分别为0.00%和7.55%，低于肥胖患者的37.04%和33.33%；两组pre-MS患病率差异有统计学意义（P＜0.05）。13~15岁组MS患病率为6.67%，低于16~19岁组的13.85%（P＜0.05）；pre-MS患病率为20.00%，高于16~19岁组的15.38%。胰岛素抵抗型患者的MS和pre-MS患病率分别为33.33%和33.33%，高于非胰岛素抵抗型患者的6.45%和11.29%（P＜0.05），ApoB/ApoA1≥0.6的患者MS和pre-MS患病率分别为33.33%和16.67%，高于ApoB/ApoA1＜0.6的患者6.45%和16.13%（P＜0.05）。结论青春期PCOS患者的MS患病率以肥胖、胰岛素抵抗型、ApoB/ApoA1≥0.6者较高，其中13~15岁人群pre-MS患病率较高。     

A simple and cost‐effective HPLC‐UV method for the detection of levetiracetam in plasma/serum of patients with epilepsy

A simple, fast and cost‐effective method was developed and validated for the determination of levetiracetam (LEV) in plasma/serum of patients using high performance liquid chromatography (HPLC) with ultraviolet detection. The stability of LEV plasma/serum samples over time and in different blood collection tubes was evaluated. Serum/plasma samples were deproteinized by methanol spiked with the internal standard, gabapentin. HPLC was carried out on a Venusil XBP C₁₈, 250 × 4.6 mm, 5 μm column, at a flow rate of 1.0 mL/min and with mobile phase consisting of 50 mm potassium dihydrogen phosphate–acetonitrile at a pH of 5.5. The UV detector was set at 205 nm and 10 μL was injected. Total runtime was 15 min. Calibration curves were linear (correlation coefficient = 0.999) over a concentration range of 1–60 μg/mL. Relative standard deviation values for both the inter‐day and intra‐day precision and accuracy were <5% for the concentration range. The influence of different collection tubes and the effect of time on the stability of LEV was investigated. These factors may cause inaccuracies owing to drug–protein binding and interference in the matrix. This method is simple, fast, cost‐effective, reliable and accurate with minimal sample preparation for daily routine use in therapeutic drug monitoring.     

Well‐balanced discontinuous Galerkin method and finite volume WENO scheme based on hydrostatic reconstruction for blood flow model in arteries

The blood flow model in arteries admits the steady state solutions, for which the flux gradient is nonzero, and is exactly balanced by the source term. In this paper, by means of hydrostatic reconstruction, we construct a high order discontinuous Galerkin method, which exactly preserves the dead‐man steady state, which is characterized by a discharge equal to zero (analogue to hydrostatic equilibrium). Moreover, the method maintains genuine high order of accuracy. Subsequently, we apply the key idea to finite volume weighted essentially non‐oscillatory schemes and obtain a well‐balanced finite volume weighted essentially non‐oscillatory scheme. Extensive numerical experiments are performed to verify the well‐balanced property, high order accuracy, as well as good resolution for smooth and discontinuous solutions.