Application of the adaptive Monte Carlo method for uncertainty evaluation in the determination of total testosterone in human serum by triple isotope dilution mass spectrometry.

The measurement uncertainty is a crucial quantitative parameter for assessing the reliability of the result. The study aimed to propose a new budget for uncertainty evaluation of a reference measurement procedure for the determination of total testosterone in human serum. The adaptive Monte Carlo method (aMCM) was used for the propagation of probability distributions assigned to various input quantities to determine the uncertainty of the testosterone concentration. The basic principles of the propagation and the statistical analysis were described based on the experimental results of the quality control serum sample. The analysis of the number of Monte Carlo trials was discussed. The procedure of validation of the GUM uncertainty framework using the aMCM was also provided. The number of Monte Carlo trials was 2.974 × 106 when the results had stabilized. The total testosterone concentration was 16.02 nmol/L, and the standard uncertainty was 0.30 nmol/L. The coverage interval at coverage probability of 95% was 15.45 to 16.62 nmol/L, while the probability distribution for testosterone concentration was approximately described by a Gaussian distribution. The validation of results was not passed as the expanded uncertainty result obtained by the aMCM was slightly lower, about 7%, than that by the GUM uncertainty framework with consistent results of the concentration.

Application of Three - dimensional Wound Analyzer in the Small Wound Area Measurement during the Process of Wound Healing.

The objective of this study was to determinate the reliability of 3-dimensional wound analyzer (3-DWMD) in the wound area measurement for animal small area in the process of wound healing. Seven Sprague-Dawley rats were used to establish the skin defect model. And the wound area and time consumption were measured on days 0, 5, 10, 15 using 3-DWMD, investigators, and planimetry method. The measurement results using 3-DWMD and investigators were analyzed comparative with that using planimetry method separately. A total 46 wounds, including 32 irregular wounds and regular 14 wounds, were measured. No matter calculating the irregular wounds or the regular wounds, there was no significant difference between 3-DWMD group and planimetry group in measuring wound area (P > 0.05). However, a statistically significant difference was found in time-consuming for measuring wound area between 3-DWMD group and planimetry group (P < 0.001). The same result was found between investigator group and planimetry group (P < 0.001). The 3-DWMD would quickly and accurately obtain the wound area, and its measurement results were consistent with planimetry method. Therefore, such measuring equipment has clinical reference value for measuring precision area of the wound in the process of wound healing.

The Variation of Hemodynamic Parameters Through PiCCO in the Early Stage After Severe Burns.

To investigate early hemodynamics of severely burned patients via PiCCO and to discuss clinical significance of hemodynamic monitoring for burn shock resuscitation, 55 extensive burn patients were enrolled in this retrospective study. The fluid resuscitation was guided according to Chinese General Formula and adjusted with urinary output of 0.5-1.0 ml/h/kg as a resuscitation goal. All patients were diagnosed within a relatively stable condition during burn shock stage, and they received PiCCO monitoring within 6 hours after burn. The preload parameter intrathoracic blood volume index was low at first, then returned to normal. The flow parameter cardiac index and myocardial contractility parameter dPmax were gradually changed from low level in the early stage to high level in the fluid reabsorption stage. The afterload parameter systemic vascular resistance index had completely opposite tendency. The lung-related parameters extravascular lung water index and pulmonary vascular permeability index were roughly in the normal range. The change of cardiac index had a linear regression relationship with dPmax and systemic vascular resistance index but had no significant relationship with intrathoracic blood volume index. Under effective fluid resuscitation, the early hemodynamics after burn is still in dynamically changing status, characterized as transition from low cardiac output (CO)-high vascular resistance in early shock stage to high CO-low vascular resistance in fluid reabsorption stage. CO mainly depends on the myocardial contractility and vascular resistance, but not on the blood volume. Excessive fluid resuscitation cannot get normal CO. The normal value of hemodynamics cannot be used as end point of burn shock resuscitation. Dynamic observation of hemodynamics is of great importance.

Active immunization with GnRH-tandem-dimer peptide in young male rats reduces serum reproductive hormone concentrations, testicular development and spermatogenesis.

GnRH sterilization vaccines have been developed for various practical and clinical reasons. However, conjugation of GnRH peptide to carrier protein has many drawbacks, hampering the further commercialization of GnRH vaccines. In this study, a new nonconjugated GnRH vaccine, D-Lys6-GnRH-tandem-dimer peptide (TDK), emulsified in Specol adjuvant was investigated for its immunocastration efficacy in young male rats. Prepubertal male rats were randomly allocated into three groups (n = 12): control (no treatment), surgically castrated or immunized against 100 µg TDK in Specol adjuvant at 6 weeks of age (with a booster 8 weeks later). Blood samples (for antibody titers and hormone concentrations) were collected at 2-week intervals until rats were killed (18 weeks of age). Compared to intact controls, active immunization against TDK reduced (P < 0.05) serum concentrations of testosterone, inhibin B, LH and FSH, prevented the onset of spermatogenesis at puberty. Furthermore, mRNA expressions of GnRH receptor, LH-ß and FSH-ß in the pituitary, LH receptor, FSH receptor, inhibin α, ßA and ßB subunit in the testes were decreased in immunocastrated rats compared to intact controls (P < 0.05). These results demonstrate for the first time that GnRH-tandem-dimer peptide emulsified in Specol is a promising veterinary sterilization medicine.

[Establishment of the evaluation reference system for domestic anti-hepatitis C virus diagnostic enzyme immunoassay kits].

OBJECTIVE: To establish the evaluation reference for domestic anti-hepatitis C virus (HCV) enzyme immunoassay (EIA) diagnostic kits. METHODS: 4833 serum samples which were collected from different provinces of China were screened with 5 domestic anti-HCV EIA kits and redetected with 2 foreign anti-HCV EIA kits. Then the selected samples were confirmed with Chiron RIBA HCV 3.0 SIA and real-time quantitative PCR reagents. The confirmed positive samples were examined for HCV genotypes. The positive samples (classified as low, medium and high titers), negative samples, mixed-titer positive dilution samples and special samples were selected for preparing the evaluation reference for anti-HCV diagnostic reagent kits. RESULTS: The established evaluation reference consisted of 30 positive serum samples including high, medium and low titers, and 10 single band samples confirmed by RIBA, and 6 dilution samples to evaluate the sensitivity, and 30 confirmed negative samples including some high negative value samples and interferential samples. CONCLUSION: The evaluation reference samples could offer dependable detection results, and covered abundant antibody repertoire, thus providing important reference for the improvement of the qualities of domestic anti-HCV EIA kits.