Objective Narcolepsy type 1 （NT1） is known to be associated with low levels of hypocretin-1 （Hcrt-1） in cerebrospinal fluid （CSF）. The standard method for Hcrt-1 measurement is radioimmunoassay （RIA） with imported reagents， but this antibody-dependent method is limited to radiation safety-certified lab， gradual radioactivity degradation， and slow turn-around time. The purpose of this study is to explore a non-radioactive， faster， and antibody independent domestic method in China for Hcrt-1 detection. Methods Repeated testing of cerebrospinal fluid from 14 clinically diagnosed NT1 patients and 10 non-narcolepsy patients was performed using liquid chromatography-tandem mass spectrometry （LC-MS/MS）technology，including the establishment and optimization of fundamental methodological procedures. The main steps involved the addition of non-radioactive isotope-labeled internal standards to the cerebrospinal fluid， followed by solid-phase extraction， mass spectrometry signal acquisition， and quantitative analysis. The results were then compared with the corresponding radioimmunoassay（RIA） findings. Results The LC-MS/MS method showed faster speed， and good linearity across a wider range of synthesized standard（5~2 500 pg/ml）， and good repeatability. Although this absolute-quantitation-based LC-MS/MS method and RIA method have different reading values in Hcrt-1 quantitation， they both can segregate NT1 group from non-NT1 group well. Conclusion Although larger cohorts are needed to set up a standard method in China，LC-MS/MS method is proved to be an easier， safer， faster， and possibly more accurate method for Hcrt-1 quantitation and detection for NT1 diagnosis.
Narcolepsy ; Radioimmunoassay

Here, we present a 40-year-old female with multiple pruritic occasionally painful vesicles, papules, and plaques in a circinate pattern on seborrheic areas, progressing to erosions and scales. Clinical findings led to the diagnosis of pemphigus foliaceus (PF). Initial treatment with prednisone and clobetasol ointment, however, did not fully suppress blister formation and healing of erosions. Skin punch biopsy revealed a subcorneal split and intracorneal neutrophilic infiltrates, while enzymelinked immunoassay (ELISA) revealed elevated anti-desmoglein 1 (Dsgl), consistent with PF. Doxycycline was then added to the previous regimen, resulting in remission. We discuss the role of doxycycline as a cost-effective adjunctive treatment in patients with refractory PF.
Pemphigus ; Clobetasol ; Enzyme-Linked Immunosorbent Assay

Introduction: Epidermolysis Bullosa Pruriginosa (EBP) is a rare subtype of the inherited Dystrophic ~ Epidermolysis Bullosa spectrum of diseases and results from a gene mutation in COL7AL Though predominantly an autosomal dominant disease, autosomal recessive and even sporadic have been reported. Case Summary: Case Summary:We report a case of a 12-year-old Filipino male presenting with a chronic history of numerous scratching-induced blisters predominantly distributed on the extensor aspect of his arms and legs without concomitant oral lesions, nail dystrophy, or hair findings, and without a family history of similar lesions. Histopathologic assessment, Direct Immunofluorescence (DIF), and Indirect Immunofiuorescence (IIF) showed a subepidermal split with scant inflammatory infiltrates, no immunofluorescence, and absent userrated linear immunofluorescence at the dermal-side of the Salt Split Skin slide, respectively, which were all consistent with EBP. Enzyme-Linked Immunosorbent Assay (ELISA) for Anti-Collagen VII antibodies was slightly elevated, which may suggest an alternative diagnosis of Epidermolysis Bullosa Acquisita (EBA). This slight elevation may be due to the mutated Collagen Vil protein becoming antigenic and therefore provoking an immune response. To conclusively distinguish EBP from EBA, a COL7AI gene mutation analysis was recommended. With a diagnosis of EBP cannot totally rule out EBA, the patient was initially managed with dapsone monotherapy, counseled regarding behavioral modification to reduce scratching and trauma, advised wound care and close monitoring for the development of oropharyngeal lesions, and recommended for COL7A1 genetic mutation analysis. Conclusion This report demonstrates a case of EBP with elevated Anti-Collagen VII antibodies. The diistinction between EBP and EBA is important because this changes the management: EBP is largely supportive, while EBA may benefit from immunosuppressive therapy.
Epidermolysis Bullosa Pruriginosa ; Enzyme-Linked Immunosorbent Assay ; Epidermolysis Bullosa Acquisita

Objective To evaluate the correlation between alterations in DNase1 and DNase1L3 enzyme activities and impairment of NET degradation in patients with sporadic SLE, and to investigate the underlying mechanism. Methods 46 sporadic SLE patients and 30 age- and sex-matched healthy individuals were recruited. Serum levels of DNase1, DNase1L3 and corresponding autoantibodies were detected by ELISA. DNase1 and DNase1L3 were isolated by immunoprecipitation; NETs and enzyme degradation activities were detected using a modified immunofluorescence. DNase1L3 secretion by PBMCs was analyzed by ELISPOT, Western blotting and reverse transcription PCR. Results Levels of H3-dsDNA and Ela-dsDNA complexes were significantly elevated in SLE patients. LDGs in SLE population was significantly higher than in the control group, and LDGs was positively correlated with H3-dsDNA and Ela-dsDNA NETs complexes. The ability of SLE patients to degrade NET in vitro was significantly lower than that of the control group. Degradation experiments of DNase1 and DNase1L3 in different proportions showed that the decrease in DNase1L3 activity was the primary contributor to the elevated NET residue level. The concentration of DNase1L3 autoantibodies in SLE patients was significantly elevated compared to the control group. In addition, the capacity of PBMCs to secrete DNase1L3 was significantly lower in the SLE patients compared to the control group. Conclusion Decreased secretion of DNase1L3 and the presence of relevant autoantibodies notably impede NET degradation in patients with SLE, offering new directions for the monitoring and treatment of SLE patients.
Humans ; Autoantibodies ; Blotting, Western ; Enzyme-Linked Immunosorbent Assay ; Extracellular Traps ; Lupus Erythematosus, Systemic

Objective To prepare and identify rabbit anti-cyclin dependent kinase 6 (CDK6) antibody. Methods The recombinant pET21a (+)/CDK6 was successfully constructed, then the recombinant plasmid was transformed into E.coli BL21 (DE3) competent cells and was induced by isopropyl-β-D-thiogalactopyranoside (IPTG) for protein expression, which was detected by SDS-PAGE and Western blot analysis. The expressed protein was purified by nickel-chelating nitrilotriacetic acid (Ni-NTA) agarose and then analyzed by SDS-PAGE. Japanese white rabbits were immunized with purified CDK6 protein for many times every two weeks. The blood was collected at 0, 2, 4 and 6 weeks after immunization, and serum was separated from blood. The titer was detected by indirect ELISA. Western blot analysis, immunofluorescence assay and immunohistochemistry were employed to determine the specificity. Results High purity CDK6 protein and high specificity of rabbit anti-CDK6 antibody were successfully prepared. The titer of CDK6 rabbit serum antibody reached 1:30 000 after immunization, which could specifically recognize the CDK6 protein expressed in cervical cancer cell line and cervical cancer tissues. Conclusion The high titer and specificity of rabbit anti-CDK6 antibody is successfully prepared.
Animals ; Female ; Humans ; Rabbits ; Antibodies ; Antibody Specificity ; Blotting, Western ; Cyclin-Dependent Kinase 6 ; Enzyme-Linked Immunosorbent Assay ; Uterine Cervical Neoplasms

Objective To prepare rabbit polyclonal antibody against mouse IQ and ubiquitin-like domain-containing protein (IQUB) and detect its expression in the mouse testis. Methods Full-length coding sequence of IQUB was inserted into the pET-30a(+) vector to construct pET-30a-IQUB recombinant prokaryotic plasmid. Transformation of pET-30a-IQUB plasmid into E. coli BL21 was performed, and protein expression was induced with isopropyl-beta-D-thiogalactoside (IPTG). The protein was purified through histidine-tagged fusion protein purification column, then denatured by treatment of urea with gradient concentration. New Zealand rabbits were immunized with the denatured protein to produce IQUB polyclonal antibody. Antibody titer was detected by ELISA, and Western blot analysis and immunofluorescence assay were employed to validate the effectiveness and specificity of IQUB antibody. Results pET-30a-IQUB recombinant plasmid was constructed, and protein expression of IQUB was induced successfully with IPTG. The titer of IQUB polyclonal antibody reached 1:1 000 000. The antibody specifically recognized the endogenous IQUB protein of testis in the wild-type adult mouse. IQUB was expressed in spermatogenic cells of different stages. It was localized in the acrosome and flagellum of mature sperms. Conclusion The highly specific rabbit anti-mouse IQUB polyclonal antibody is successfully prepared, which can be used for Western blot and immunofluorescence histochemistry.
Male ; Rabbits ; Animals ; Mice ; Ubiquitins ; Escherichia coli/genetics* ; Isopropyl Thiogalactoside ; Antibodies ; Enzyme-Linked Immunosorbent Assay

Objective To investigate the fluorescence resonance energy transfer (FRET) effect between dylight (DL) and AuNP (AuNP), and to construct a new fluorescence immunoassay for insulin in combination with the immunocompetition method. Methods Insulin antigen (Ag) and insulin antibody (Ab) were conjugated with DL and AuNP respectively to form DL-Ag conjugate and AUNp-AB conjugate. A novel fluorescence immunoassay for insulin was developed on the basis of FRET effect and the immune competition response between them. Then the performance of the method was evaluated and its application in actual samples was explored. Results The fluorescence immunoassay showed high sensitivity (0.015 ng/mL), short measurement time (4 min) and good specificity. It was successfully used in the measurement of serum insulin, and the recovery was between 96.9% and 121.1%. Conclusion FRET effect between AuNP and DL can be applied to develop a fluorescence immunoassay for the measurement of serum insulin.
Fluorescence Resonance Energy Transfer ; Insulin ; Immunoassay

Objective To produce rabbit polyclonal antibody against mouse testis expressed 38 (TEX38). Methods Full-length open reading frame sequence of TEX38 was amplified and inserted into the pET-30a-(+) vector to construct pET-30a-TEX38 prokaryotic plasmid. The recombinant plasmid was transformed into E.coli BL21, and expression was induced with isopropyl β-D-thiogalactopyranoside (IPTG). New Zealand white rabbits were immunized with TEX38 protein after purification and denaturation, then TEX38 polyclonal antibodies were collected from rabbit serum samples. ELISA was performed to detect the antibody titer. Western blot and immunofluorescence staining were performed to determine the specificity of TEX38 polyclonal antibodies. Results The pET-30a-TEX38 recombinant plasmid was constructed, and TEX38 prokaryotic protein was expressed and purified successfully. After immunization, the titer of TEX38 antibody reached 1:1 000 000. Western blot analysis and immunofluorescence staining showed that TEX38 was localized in the mouse spermatogenic cells and sperms with a good specificity. Conclusion The rabbit polyclonal antibody against mouse TEX38 is successfully produced, and the expression of TEX38 in mouse spermatogenic cells and sperms is validated.
Male ; Rabbits ; Animals ; Mice ; Testis ; Antibodies ; Enzyme-Linked Immunosorbent Assay ; Immunization ; Spermatozoa ; Escherichia coli

Objective To compare the sensitivity and accuracy of amplified luminescent proximity homogeneous assay linked immunosorbent assay (AlphaLISA) and magnetic particles-based chemiluminescence immunoassay (MP-CLIA) for detection of staphylococcal enterotoxin C (SEC) in the simulated milk samples. Methods The AlphaLISA was constructed using goat anti-SEC polyclonal antibody-coupled receptor microspheres, biotin-labeled SEC monoclonal antibody and streptavidin-coupled donor microspheres. The MP-CLIA was constructed using goat anti-SEC polyclonal antibody conjugated alkaline phosphatase, biotin-labeled anti-SEC monoclonal antibody and streptavidin conjugated magnetic beads. Results The sensitivity of AlphaLISA to detect SEC content in simulated milk samples was 4.04 ng/L, and the coefficient of variation (CV) was 1.98%~9.82%. The sensitivity of MP-CLIA was 108.19 ng/L and CV was 4.63%~20.40%. Conclusion Compared with MP-CLIA, AlphaLISA is more sensitive and accurate to detecting SEC.
Animals ; Streptavidin ; Biotin ; Luminescence ; Milk ; Antibodies, Monoclonal ; Goats ; Immunoassay/methods*

Objective To prepare rabbit polyclonal antibody specifically against human lactate dehydrogenase C4 (LDHC4). Methods Site-directed mutation was performed by PCR to generate the mutated LDHC gene, and the mutated gene was ligated into the pET-28a vector to form the pET-28a-LDHC recombinant expression vector. The recombinant vector was introduced into E. coli BL21 (DE3), and LDHC4 protein was obtained by induced expression. The recombinant protein was used as an antigen to immunize New Zealand rabbits, and the antiserum was obtained after three boosted immunizations. The titer of the antiserum against LDHC4 were detected by ELISA. Western blot was used to detect the specificity of the antiserum, and immunohistochemistry was used to detect the expression of LDHC4 in human triple-negative breast cancer tissue. Results A specific rabbit anti-human LDHC4 polyclonal antibody was obtained with an antibody titer of 1:51 200. The antibody can be used for Western blot and immunohistochemistry. Conclusion The specific rabbit anti-human LDHC4 polyclonal antibody is successfully prepared.
Humans ; Rabbits ; Animals ; Escherichia coli/genetics* ; Antibodies ; Enzyme-Linked Immunosorbent Assay ; L-Lactate Dehydrogenase/metabolism* ; Blotting, Western ; Antibody Specificity