Assessments of different inactivating reagents in formulating transmissible gastroenteritis virus vaccine.

BACKGROUND: Transmissible gastroenteritis virus (TGEV) causes enteric infection in piglets, characterized by vomiting, severe diarrhea and dehydration, and the mortality in suckling piglets is often high up to 100%. Vaccination is an effective measure to control the disease caused by TGEV. METHODS: In this study, cell-cultured TGEV HN-2012 strain was inactivated by formaldehyde (FA), ß-propiolactone (BPL) or binaryethylenimine (BEI), respectively. Then the inactivated TGEV vaccine was prepared with freund's adjuvant, and the immunization effects were evaluated in mice. The TGEV-specific IgG level was detected by ELISA. The positive rates of CD4+, CD8+, CD4+IFN-γ+, CD4+IL-4+ T lymphocytes were detected by flow cytometry assay. Lymphocyte proliferation assay and gross pathology and histopathology examination were also performed to assess the three different inactivating reagents in formulating TGEV vaccine. RESULTS: The results showed that the TGEV-specific IgG level in FA group (n = 17) was earlier and stronger, while the BEI group produced much longer-term IgG level. The lymphocyte proliferation test demonstrated that the BEI group had a stronger ability to induce spleen lymphocyte proliferation. The positive rates of CD4+ and CD8+ T lymphocyte subsets of peripheral blood lymphocyte in BEI group was higher than that in FA group and BPL groups by flow cytometry assay. The positive rate of CD4+IFN-γ+ T lymphocyte subset was the highest in the BPL group, and the positive rate of CD4+IL-4+ T lymphocyte subset was the highest in the FA group. There were no obvious pathological changes in the vaccinated mice and the control group after the macroscopic and histopathological examination. CONCLUSIONS: These results indicated that all the three experimental groups could induce cellular and humoral immunity, and the FA group had the best humoral immunity effect, while the BEI group showed its excellent cellular immunity effect.

General Guidelines for Quality Assurance of Immunohistochemistry in a Mohs Lab.

BACKGROUND: The adoption of recently created protocols introduces Mohs laboratories to the principles of immunohistochemistry (IHC) performance validation and clinical laboratory regulations that are unique to these evolving technologies. OBJECTIVE: To review Food and Drug Administration (FDA) IHC reagent classifications, IHC validation protocols, and quality assurance (QA) procedures and documentation needed in conjunction with IHC test guidelines. METHODS: A focused review of IHC reagent classifications and guidelines in clinical testing laboratories was conducted using PubMed and FDA source documents. RESULTS: The IHC regulation requirements are determined by the 3 FDA classifications of reagents: in vitro diagnostic reagents, analyte-specific reagents, and research use only reagents. To account for performance variability, IHC reagents benefit from routine validation and QA programs. We present our IHC adoption procedures for QA and documentation of IHC tests in a Mohs laboratory. CONCLUSION: Incorporating a well-organized IHC validation and QA program into Mohs laboratories can increase regulatory compliance and reagent performance.

Medical Devices; Clinical Chemistry and Clinical Toxicology Devices; Classification of the Reagents for Molecular Diagnostic Instrument Test Systems. Final order.

The Food and Drug Administration (FDA or we) is classifying the reagents for molecular diagnostic instrument test systems into class I (general controls). We are taking this action because we have determined that classifying the device into class I (general controls) will provide a reasonable assurance of safety and effectiveness of the device. We believe this action will also enhance patients' access to beneficial innovative devices, in part by reducing regulatory burdens.

Risk-based Strategy to Determine Testing Requirement for the Removal of Residual Process Reagents as Process-related Impurities in Bioprocesses.

UNLABELLED: The purpose of this article is to recommend a risk-based strategy for determining clearance testing requirements of the process reagents used in manufacturing biopharmaceutical products. The strategy takes account of four risk factors. Firstly, the process reagents are classified into two categories according to their safety profile and history of use: generally recognized as safe (GRAS) and potential safety concern (PSC) reagents. The clearance testing of GRAS reagents can be eliminated because of their safe use historically and process capability to remove these reagents. An estimated safety margin (Se) value, a ratio of the exposure limit to the estimated maximum reagent amount, is then used to evaluate the necessity for testing the PSC reagents at an early development stage. The Se value is calculated from two risk factors, the starting PSC reagent amount per maximum product dose (Me), and the exposure limit (Le). A worst-case scenario is assumed to estimate the Me value, that is common. The PSC reagent of interest is co-purified with the product and no clearance occurs throughout the entire purification process. No clearance testing is required for this PSC reagent if its Se value is ≥1; otherwise clearance testing is needed. Finally, the point of the process reagent introduction to the process is also considered in determining the necessity of the clearance testing for process reagents. How to use the measured safety margin as a criterion for determining PSC reagent testing at process characterization, process validation, and commercial production stages are also described. LAY ABSTRACT: A large number of process reagents are used in the biopharmaceutical manufacturing to control the process performance. Clearance testing for all of the process reagents will be an enormous analytical task. In this article, a risk-based strategy is described to eliminate unnecessary clearance testing for majority of the process reagents using four risk factors. The risk factors included in the strategy are (i) safety profile of the reagents, (ii) the starting amount of the process reagents used in the manufacturing process, (iii) the maximum dose of the product, and (iv) the point of introduction of the process reagents in the process. The implementation of the risk-based strategy can eliminate clearance testing for approximately 90% of the process reagents used in the manufacturing processes. This science-based strategy allows us to ensure patient safety and meet regulatory agency expectations throughout the product development life cycle.

Medical devices; immunology and microbiology devices; classification of dengue virus nucleic acid amplification test reagents. Final order.

The Food and Drug Administration (FDA) is classifying dengue virus nucleic acid amplification test reagents into class II (special controls). The Agency is classifying the device into class II (special controls) because special controls, in addition to general controls, will provide a reasonable assurance of safety and effectiveness of the device.

Medical devices; immunology and microbiology devices; classification of dengue virus serological reagents. Final order.

The Food and Drug Administration (FDA) is classifying dengue virus serological reagents into class II (special controls). The special controls that will apply to the device are identified in this order, and the codified language for the dengue serological reagents classification will include the identification of the special controls that will apply to this device. The Agency is classifying the device into class II (special controls) because special controls, in addition to general controls, will provide a reasonable assurance of safety and effectiveness of the device.

Protein C assay performance: an analysis of North American specialized coagulation laboratory association proficiency testing results.

To determine the performance and frequency of protein C reagents currently used by clinical laboratories, we analyzed North American Specialized Coagulation Laboratory Association (NASCOLA) protein C proficiency testing data from 6 surveys conducted in 2009 and 2010 (2009-1 to 2009-3 and 2010-1 to 2010-3). Interlaboratory coefficients of variation (CV) for commonly used reagents on a survey with normal protein C ranged from 8% to 12% for antigenic assays, from 4% to 7% for chromogenic activity assays, and from 7% to 22% for clot-based activity assays. CVs for commonly used reagents on specimens with abnormal protein C ranged from 15% to 24% for antigenic, 4% to 11% for chromogenic, and 10% to 17% for clot-based assays (averaged across 3 surveys). Some reagents were used by relatively few laboratories and therefore additional study may be needed for those reagents. For all commonly used reagents, biases were usually small and often not statistically significant. All assessed reagents were clinically accurate, and were considered acceptable options for a specialized coagulation laboratory.

Recommendations for appropriate activated partial thromboplastin time reagent selection and utilization.

The activated partial thromboplastin time (aPTT) is widely used as a screening coagulation test and for monitoring unfractionated heparin therapy. Various commercial reagents are available, with different performance characteristics, particularly responsiveness to the lupus anticoagulant (LA). Because aPTT reagent selection significantly affects the interpretation of results, we reviewed College of American Pathologists proficiency testing data involving approximately 4,000 coagulation laboratories, and conducted a survey of coagulation laboratories (n = 93) using The Fritsma Factor hemostasis Web site to determine the basis for aPTT reagent selection. The data demonstrate that for routine aPTT testing, most laboratories use reagents with high/moderate responsiveness to LA. Significant misunderstanding was apparent regarding the use of appropriate aPTT reagent for routine testing and LA identification. We recommend aPTT reagents with low LA responsiveness to screen for coagulation factor deficiencies and heparin monitoring, and suggest continued education of laboratory professionals and reagent manufacturers about appropriate aPTT reagent use.

Medical devices; immunology and microbiology devices; classification of norovirus serological reagents. Final rule.

The Food and Drug Administration (FDA) is classifying norovirus serological reagents into class II (special controls). The special control that will apply to these devices is the guidance document entitled ``Class II Special Controls Guidance Document: Norovirus Serological Reagents.'' The Agency is classifying these devices into class II (special controls) because special controls, in addition to general controls, will provide a reasonable assurance of safety and effectiveness of these devices and there is sufficient information to establish special controls.

[Studies on administration of in-vitro diagnostic reagents].

This article introduces the definition, classification, premarket admission and other administering specialities about In-Vitro Diagnostic Reagents in the U.S.A. and China. And by analyzing manufacture and administration of In-Vitro Diagnostic Reagents in our country, It is pointed out that a suitable administering model in accordance with the characteristics of In-Vitro Diagnostic Reagents should be adopted to perfect the administration.

Transfection efficiency and cytotoxicity of nonviral gene transfer reagents in human smooth muscle and endothelial cells.

PURPOSE: Evaluation of a nonviral transfection reagent with respect to efficient gene transfer into primary human vascular cells. METHODS: Complexes consisting of seven commercially available transfection reagents (DAC-30, DC-30, Lipofectin, LipofectAMINE PLUS, Effectene, FuGene 6 and Superfect) and EGFP encoding plasmid DNA were studied. The in vitro transfection efficiency and cytotoxicity in human aorta smooth muscle cells (HASMCs) and endothelial cells (HAECs) and rat smooth muscle cells (A-10 SMCs) were assayed in the presence of serum using flow cytometric analysis and ATP-quantitation assay, respectively. RESULTS: Human primary cells were transfected less efficiently compared to the rat smooth muscle cell line. Transfection efficiency depended on the type of reagent, the reagent/DNA ratio, and, most importantly, on the cell type used. Determination of cytotoxicity showed that the effects of transfection on cell viability did not significantly differ from one another depending on the cell type. The exception to this was Superfect, which obviously reduced cell viability in all cell types. CONCLUSIONS: Our experiments showed that DAC-30 is the preferred transfection reagent for HASMCs and HAECs, exhibiting an improved efficiency combined with an acceptable cytotoxicity. Therefore, it might offer a therapeutic option for the treatment of cardiovascular disease and prove suitable for further drug development.

Enhancement of muddy footwear impressions.

Methods for chemical enhancement of muddy footwear impressions were compared in order to differentiate between utilisation at the scene of crime, the local (regional) police laboratory and the Netherlands Forensic Institute (NFI)

Analyte specific reagents: FDA final rule and implications for your clinical flow cytometry laboratory.

In summary, the FDA Final Rule on Analyte Specific Reagents has provided clarity and simplification for manufactures to develop and market products. The burden of establishing performance characteristics is now the responsibility of the clinical flow cytometry laboratory. The FDA now requires a disclaimer to be included in every lab report utilizing these products.

An approach to discriminating 25 commercial chiral stationary phases from structural data sets extracted from a molecular database.

We have developed a comprehensive molecular database (CHIRBASE) which contains today the results of 35,000 chiral separations by liquid chromatography, 2-D Structural searches have been used to determine at which frequency a molecular characteristic is present in a population of compounds separated on a given chiral stationary phase. To simplify the screening, we have searched 15 empirical molecular descriptors in a selection of 5000 solutes separated on 25 stationary phases. A correspondence analysis was then performed on this set of data (graphical representation of CSPs and descriptors). We then attempt to classify the behaviour of chromatographic systems with the help of hierarchical ascending classification.