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1.
J Clin Microbiol ; 62(3): e0104823, 2024 03 13.
Article in English | MEDLINE | ID: mdl-38329335

ABSTRACT

Human granulocytic anaplasmosis (HGA) is an emerging, rickettsial tick-borne disease caused by Anaplasma phagocytophilum. Sero-epidemiological data demonstrate that this pathogen has a worldwide distribution. The diagnosis of HGA requires a high index of clinical suspicion, even in endemic areas. In recent years, HGA has increasingly been reported from Asia and described in China, Japan, and Korea. We serologically and molecularly screened 467 patients with clinical suspicion of Anaplasmosis. The present study describes the epidemiology, clinical, and laboratory details of 6 confirmed and 43 probable cases of human granulocytic anaplasmosis. One of the HGA patients developed secondary invasive opportunistic Aspergillus fumigatus and Acinetobacter baumanii infection during the illness, which resulted in a fatal infection. The HGA patients without severe complications had excellent treatment responses to doxycycline. The emergence of this newly recognized tick-borne zoonotic HGA in North India is a significant concern for public health and is likely underdiagnosed, underreported, and untreated. Hence, it is also essential to establish a well-coordinated system for actively conducting tick surveillance, especially in the forested areas of the country.IMPORTANCEThe results of the present study show the clinical and laboratory evidence of autochthonous cases of Anaplasma phagocytophilum in North India. The results suggest the possibility of underdiagnosis of HGA in this geographical area. One of the HGA patients developed secondary invasive opportunistic Aspergillus fumigatus and Acinetobacter baumanii infection during the illness, which resulted in a fatal infection.


Subject(s)
Anaplasma phagocytophilum , Anaplasmosis , Tick-Borne Diseases , Animals , Humans , Anaplasmosis/diagnosis , Anaplasmosis/drug therapy , Anaplasmosis/epidemiology , Doxycycline/therapeutic use , China/epidemiology , India
2.
Muscle Nerve ; 69(5): 626-630, 2024 May.
Article in English | MEDLINE | ID: mdl-38321821

ABSTRACT

INTRODUCTION/AIMS: Line blot (LB) is in widespread use for myositis antibody detection. Yet, studies of its positive predictive value (PPV) in patients with suspected idiopathic inflammatory myopathy (IIM), which would be of particular relevance to neuromuscular clinicians, are lacking. We aimed to determine the PPV of myositis antibody LB testing in patients with suspected IIM, and examine whether PPV was significantly impacted by intensity of antibody positivity. METHODS: This was a retrospective study of patients who underwent myositis antibody LB testing for suspected IIM between March 2019 and August 2022. RESULTS: Of 70 patients who underwent testing for suspected IIM and had positive myositis antibody LB results, 43 (61%) were female and the median age was 61 years (range: 10-83 years). Forty-four were classified as true-positives, yielding a PPV of 63%. The PPV of patients with weak-positive myositis antibody results (14/30, 47%) was significantly lower than the PPV of patients with moderate-positive or strong-positive myositis antibody results (30/40, 75%) (p = .02). DISCUSSION: Our study found that myositis antibody LB testing in patients with suspected IIM had a modest PPV, underscoring the need for antibody interpretation in the context of all available clinical and ancillary test data to avoid misdiagnosis. The significantly lower PPV in patients with weak-positive results emphasizes the particular importance of clinical correlation in such patients. Further study into the diagnostic performance of various LBs for myositis antibody detection is needed to inform their interpretation in clinical practice.


Subject(s)
Autoantibodies , Myositis , Humans , Female , Middle Aged , Male , Predictive Value of Tests , Retrospective Studies , Myositis/diagnosis
3.
Am J Physiol Heart Circ Physiol ; 325(4): H601-H616, 2023 10 01.
Article in English | MEDLINE | ID: mdl-37539459

ABSTRACT

The modification of serine and threonine amino acids of proteins by O-linked N-acetylglucosamine (O-GlcNAc) regulates the activity, stability, function, and subcellular localization of proteins. Dysregulation of O-GlcNAc homeostasis is well established as a hallmark of various cardiac diseases, including cardiac hypertrophy, heart failure, complications associated with diabetes, and responses to acute injuries such as oxidative stress and ischemia-reperfusion. Given the limited availability of site-specific O-GlcNAc antibodies, studies of changes in O-GlcNAcylation in the heart frequently use pan-O-GlcNAc antibodies for semiquantitative evaluation of overall O-GlcNAc levels. However, there is a high degree of variability in many published cardiac O-GlcNAc blots. For example, many blots often have regions that lack O-GlcNAc positive staining of proteins either below 50 or above 100 kDa. In some O-GlcNAc blots, only a few protein bands are detected, while in others, intense bands around 75 kDa dominate the gel due to nonspecific IgM band staining, making it difficult to visualize less intense bands. Therefore, the goal of this study was to develop a modifiable protocol that optimizes O-GlcNAc positive banding of proteins in cardiac tissue extracts. We showed that O-GlcNAc blots using CTD110.6 antibody of proteins ranging from <30 to ∼450 kDa could be obtained while also limiting nonspecific staining. We also show that some myofilament proteins are recognized by the CTD110.6 antibody. Therefore, by protocol optimization using the widely available CTD110.6 antibody, we found that it is possible to obtain pan-O-GlcNAc blots of cardiac tissue, which minimizes common limitations associated with this technique.NEW & NOTEWORTHY The post-translational modification of proteins by O-linked N-acetylglucosamine (O-GlcNAc) is recognized as mediating cardiac pathophysiology. However, there is considerable variability in the quality of O-GlcNAc immunoblots used to evaluate changes in cardiac O-GlcNAc levels. Here we show that with relatively minor changes to a commonly used protocol it is possible to minimize the intensity of nonspecific bands while also reproducibly generating O-GlcNAc immunoblots covering a range of molecular weights from <30 to ∼450 kDa.


Subject(s)
Acetylglucosamine , Proteins , Acetylglucosamine/chemistry , Acetylglucosamine/metabolism , Proteins/metabolism , Heart , Antibodies , Immunoblotting , Protein Processing, Post-Translational , N-Acetylglucosaminyltransferases/genetics , N-Acetylglucosaminyltransferases/metabolism
4.
Am J Physiol Heart Circ Physiol ; 324(5): H637-H653, 2023 05 01.
Article in English | MEDLINE | ID: mdl-36867445

ABSTRACT

We previously reported that exercise training drives enhanced agonist-stimulated hydrogen peroxide (H2O2) levels and restores endothelium-dependent dilation via an increased reliance on H2O2 in arterioles isolated from ischemic porcine hearts. In this study, we tested the hypothesis that exercise training would correct impaired H2O2-mediated dilation in coronary arterioles isolated from ischemic myocardium through increases in protein kinase G (PKG) and protein kinase A (PKA) activation and subsequent colocalization with sarcolemmal K+ channels. Female adult Yucatan miniature swine were surgically instrumented with an ameroid constrictor around the proximal left circumflex coronary artery, gradually inducing a collateral-dependent vascular bed. Arterioles (∼125 µm) supplied by the left anterior descending artery served as nonoccluded control vessels. Pigs were separated into exercise (treadmill; 5 days/wk for 14 wk) and sedentary groups. Collateral-dependent arterioles isolated from sedentary pigs were significantly less sensitive to H2O2-induced dilation compared with nonoccluded arterioles, whereas exercise training reversed the impaired sensitivity. Large conductance calcium-activated potassium (BKCa) channels and 4AP-sensitive voltage-gated (Kv) channels contributed significantly to dilation in nonoccluded and collateral-dependent arterioles of exercise-trained but not sedentary pigs. Exercise training significantly increased H2O2-stimulated colocalization of BKCa channels and PKA, but not PKG, in smooth muscle cells of collateral-dependent arterioles compared with other treatment groups. Taken together, our studies suggest that with exercise training, nonoccluded and collateral-dependent coronary arterioles better use H2O2 as a vasodilator through increased coupling with BKCa and 4AP-sensitive Kv channels; changes that are mediated in part by enhanced colocalization of PKA with BKCa channels.NEW & NOTEWORTHY The current study reveals that coronary arterioles distal to stenosis display attenuated dilation responses to H2O2 that are restored with endurance exercise training. Enhanced H2O2 dilation after exercise is dependent on Kv and BKCa channels and at least in part on in colocalization of BKCa channel and PKA and independent of PKA dimerization. These findings expand our earlier studies which demonstrated that exercise training drives beneficial adaptive responses of reactive oxygen species in the microvasculature of the ischemic heart.


Subject(s)
Hydrogen Peroxide , Vasodilation , Swine , Female , Animals , Hydrogen Peroxide/pharmacology , Hydrogen Peroxide/metabolism , Arterioles/metabolism , Swine, Miniature/metabolism , Vasodilator Agents/pharmacology , Coronary Vessels/metabolism
5.
J Clin Microbiol ; 61(10): e0035423, 2023 10 24.
Article in English | MEDLINE | ID: mdl-37728898

ABSTRACT

This study aimed to evaluate different serological strategies for the postnatal diagnosis of congenital toxoplasmosis (CT) and establish a biological algorithm for CT diagnosis. The study analyzed serological data of immunoglobulins M, A, and G (IgM, IgA, IgG) performed by immunoenzymatic and compared immunological profile (CIP) assays in 668 newborns with CT diagnosis across four testing periods: P1 (D0- D10), P2 (D11-D35), P3 (D36-D45), and P4 (>D45). Forty-nine percent of the 668 CT cases were diagnosed during P1 and 34%, 4%, and 12% during P2, P3, and P4, respectively. CIP assays detected neosynthetized IgMs/IgGs in 98% of CT cases diagnosed during P1, while IgMs and IgAs were detected in 90% and 57% of CT cases diagnosed during P2 and in 88% and 67% of diagnoses made during P3, respectively. Detection of neosynthesized IgMs/IgGs, IgMs, and IgAs by immunoassay contributed to CT diagnosis in 81%, 77%, and 60% of cases, respectively. In total, 46% of serum samples were positive for all three parameters, 27% for two, and 27% for one of the three. The study recommends using the CIP assay as standard during P1 for CT diagnosis and IgM and IgA immunoassays after P1. A clinical and biological follow-up in a specialized center with a close collaboration between biologists and clinicians is highly recommended to increase the chances of early diagnosis. Overall, this study provides useful information for the development of a biological algorithm for CT diagnosis, which can aid in early detection and appropriate treatment of this disease.


Subject(s)
Toxoplasma , Toxoplasmosis, Congenital , Infant, Newborn , Humans , Toxoplasmosis, Congenital/diagnosis , Retrospective Studies , Antibodies, Protozoan , Immunoglobulin M , Immunoglobulin G , Immunoglobulin A
6.
J Clin Microbiol ; 61(6): e0011223, 2023 06 20.
Article in English | MEDLINE | ID: mdl-37222630

ABSTRACT

Treponema pallidum subsp. pallidum is a fastidious spirochete and the etiologic agent of syphilis, a sexually transmitted infection (STI). Syphilis diagnoses and disease staging are based on clinical findings and serologic testing. Moreover, according to most international guidelines, PCR analysis of swab samples from genital ulcers is included in the screening algorithm where possible. It has been suggested that PCR might be omitted from the screening algorithm due to low added value. As an alternative to PCR, IgM serology might be used. In this study, we wanted to establish the added value of PCR and IgM serology for diagnosing primary syphilis. Added value was defined as finding more cases of syphilis, preventing overtreatment, or limiting the extent of partner notification to more recent partners. We found that both PCR and IgM immunoblotting could aid the timely diagnosis of early syphilis in ~24% to 27% of patients. PCR has the greatest sensitivity and can be applied to cases with an ulcer with suspected reinfection or primary infection. In the absence of lesions, the IgM immunoblot could be used. However, the IgM immunoblot has better performance in cases with suspected primary infection than in reinfections. The target population, testing algorithm, time pressures, and costs should determine whether either test provides sufficient value to be implemented in clinical practice.


Subject(s)
Diagnostic Tests, Routine , Immunoglobulin M , Syphilis , Humans , Immunoblotting/standards , Immunoglobulin M/analysis , Polymerase Chain Reaction/standards , Syphilis/diagnosis , Syphilis/immunology , Syphilis/microbiology , Treponema pallidum/genetics , Serologic Tests/standards , Diagnostic Tests, Routine/economics , Diagnostic Tests, Routine/methods , Diagnostic Tests, Routine/standards , Sensitivity and Specificity
7.
J Investig Allergol Clin Immunol ; 33(5): 383-391, 2023 Oct 16.
Article in English | MEDLINE | ID: mdl-36000827

ABSTRACT

BACKGROUND: Vine cultivation is widely distributed in La Rioja, Spain (37% of all crops) and is associated with exposure of the general population to vine pollen. The aims of this study were to investigate the prevalence of sensitization to Vitis vinifera pollen in persons with respiratory allergy in the general population and to identify the allergens involved. MATERIALS AND METHODS: The study population comprised patients who came to the hospital between September 2019 and January 2020 with suspected respiratory allergy. All patients underwent skin prick testing with a panel of standardized aeroallergens, profilin, lipid transfer protein (LTP), and V vinifera pollen extract and prick-prick testing with fresh grapes. The in vitro study included specific IgE by ImmunoCap and ELISA, allergenic profile by immunoblot with individual sera from patients positive to V vinifera pollen extract, and 2D immunoblot with a pool of sera. The spots recognized by IgE were identified using mass spectrometry. RESULTS: A total of 151 patients were included. Of these, 124 were positive to some of the allergens tested. Thirty-four (27.4%) were positive to vine pollen in the skin prick tests. The serology study revealed positive results in 20 patients. Five vine pollen allergens were identified, and profilin was the most prevalent (30%). The other 4 allergens could be considered specific to this pollen. CONCLUSIONS: Sensitization to vine pollen was frequent in the general population in a vine growing area. The clinical relevance of this finding is unknown owing to sensitization to other pollens in the vine pollen-positive patients. Five new vine pollen allergens were identified.

8.
BMC Geriatr ; 23(1): 274, 2023 05 05.
Article in English | MEDLINE | ID: mdl-37147588

ABSTRACT

BACKGROUND: In the 19th century, neurosyphilis was the most frequent cause of dementia in Western Europe. Now dementia caused by syphilis has become rare in Germany. We studied whether routine testing of patients with cognitive abnormalities or neuropathy for antibodies against Treponema pallidum has therapeutic consequences in geriatric patients. METHODS: A Treponema pallidum electrochemiluminescence immunoassay (TP-ECLIA) is routinely performed in all in-patients treated at our institution with cognitve decline or neuropathy and no or insufficient previous diagnostic workup. Patients with a positive TP-ECLIA treated from October 2015 to January 2022 (76 months) were retrospectively evaluated. In cases of positive TP-ECLIA, further specific laboratory investigations were performed to assess whether antibiotic therapy was indicated. RESULTS: In 42 of 4116 patients (1.0%), TP-ECLIA detected antibodies directed against Treponema in serum. Specifity of these antibodies was ensured by immunoblot in 22 patients (11 × positiv, 11 × borderline values). Treponema-specific IgM was detectable in the serum of one patient, in 3 patients the Rapid Plasma Reagin (RPR) test, a modified Venereal Disease Research Laboratory test (VDRL), in serum was positiv. CSF analysis was performed in 10 patients. One patient had CSF pleocytosis. In 2 other patients, the Treponema-specific IgG antibody index was elevated. 5 patients received antibiotic therapy (4 × ceftriaxone 2 g/d i.v., 1 × doxycycline 300 mg/d p.o.). CONCLUSION: In approx. 1‰ of patients with previously undiagnosed or not sufficiently diagnosed cognitive decline or neuropathy, the diagnostic workup for active syphilis resulted in a course of antibiotic treatment.


Subject(s)
Cognitive Dysfunction , Dementia , Polyneuropathies , Syphilis , Humans , Aged , Syphilis/complications , Syphilis/diagnosis , Syphilis/drug therapy , Diagnosis, Differential , Retrospective Studies , Treponema pallidum , Polyneuropathies/diagnosis , Anti-Bacterial Agents , Cognitive Dysfunction/diagnosis , Dementia/diagnosis
9.
Mod Rheumatol ; 33(3): 543-548, 2023 Apr 13.
Article in English | MEDLINE | ID: mdl-35662349

ABSTRACT

OBJECTIVE: To develop a multianalyte assay for the detection of dermatomyositis (DM)-related autoantibodies using immunoprecipitation (IP) combined with immunoblotting (IB). METHODS: Sera from 116 DM patients were subjected to RNA and protein immunoprecipitation assays as well as commercial enzyme-linked immunosorbent assays (ELISAs) for anti-aminoacyl transfer RNA synthetase, anti-melanoma differentiation antigen 5 (MDA5), anti-Mi-2, anti-transcriptional intermediary factor-1γ (TIF-1γ), and anti-U1 ribonucleoprotein antibodies. The IP/IB assay was developed by immunoprecipitation of autoantigens from HeLa cell extracts using patient sera, followed by immunoblotting with an antibody against Mi-2, TIF-1γ, OJ, nuclear matrix protein (NXP)-2, MDA5, PM/Scl, small ubiquitin-like modifier activating enzyme (SAE), or Ku. A multianalyte assay was designed by mixing primary antibodies in the IP/IB assay. RESULTS: IP assays identified any DM-related autoantibodies in 100 patients (86%), of which 82% were covered by commercial ELISAs, with a false-positive result in two sera and a false-negative result in one serum. The results obtained from the multianalyte IP/IB assay and 'gold-standard' IP assays were concordant in terms of the presence or absence of anti-MDA5, anti-TIF-1γ, anti-OJ, anti-NXP-2, anti-PM/Scl, anti-SAE, anti-Mi-2, and anti-Ku antibodies. CONCLUSION: This multianalyte IP/IB assay combined with commercial ELISAs is an alternative to 'gold-standard' IP assays for the detection of DM-related autoantibodies.


Subject(s)
Dermatomyositis , Humans , HeLa Cells , Autoantibodies , Immunoprecipitation , Immunoblotting , Biomarkers , Antibodies, Antinuclear
10.
Biochem Biophys Res Commun ; 607: 110-116, 2022 06 04.
Article in English | MEDLINE | ID: mdl-35367822

ABSTRACT

When performing western blots for protein detection using the classical Laemmli method, experimenters often encounter difficulties with the detection of transmembrane proteins involved in lipid or fatty acid metabolism. A crucial phase in sample preparation is heating the samples to 100 °C in a Laemmli sample buffer containing SDS before separation by polyacrylamide gel electrophoresis (PAGE). In the current study, the analysis of several proteins was performed following modifications of the heating step during sample preparation. Multiple samples of the human Jurkat cell line were prepared using commercial or homemade Laemmli sample buffer. Samples were subjected to incubation at different temperatures for varying periods of time prior to separation by SDS-PAGE, transfer onto PVDF membranes and detection with specific antibodies. In samples incubated at temperatures of 25 °C, 40 °C, 70 °C and 100 °C, detection of the transmembrane protein elongase of long chain fatty acids 5 (ELOVL5) significantly decreased with temperature to a near total absence of signal at 100 °C. Heating (100 °C) the samples even for 1 min resulted in significant loss of ELOVL5 band intensity that was associated with the appearance of higher molecular weight immunoreactive materials. Loss of ELOVL5 band intensity was also observed with heating of samples at 100 °C prepared from HepG2, HEK293, MCF-7 and SKRB cells. The robust induction of ELOVL5 in stimulated primary T cells was not detected when sample were heated. The detection of fatty acid-metabolizing enzymes stearoyl-CoA desaturase-1 and long-chain-fatty-acid-CoA ligases 3 and 4 showed bands with significantly less intensity after heating at 100 °C compared to samples prepared at room temperature. Heating samples at 100 °C did not affect the detection of transmembrane proteins ERBB2 and five-lipoxygenase activating protein, or the soluble 5-lipoxygenase protein. Overall, the number of transmembrane passes of a protein was not predictive of loss of band intensity after heating, however this study indicates that sample heating can drastically affect the ability to detect proteins following separation by SDS-PAGE. This has implications for any detection methods that follow SDS-PAGE.


Subject(s)
Fatty Acids , Heating , Blotting, Western , Electrophoresis, Polyacrylamide Gel , HEK293 Cells , Humans , Proteins
11.
Eur J Clin Microbiol Infect Dis ; 41(1): 155-161, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34518964

ABSTRACT

For diagnosis of neuroborreliosis, calculation of the antibody index, based on Euroimmun Anti-Borrelia plus VlsE ELISA was compared to Virotech Borrelia Europe plus TpN17 immunoblot-based detection of Borrelia-specific intrathecal antibody production. CXCL13 results in cerebrospinal fluid were used to evaluate discordant results. A total of 64 serum/CSF pairs were analysed. Patients were classified according to European Federation of Neurological Societies criteria incorporating Virotech results. For the Euroimmun assay, a sensitivity of 100% and specificity of 94% was found. Agreement between the both tests was almost perfect (κ 0.81). Both methods are appropriate for the detection of Borrelia-specific intrathecal antibody production.


Subject(s)
Antibodies, Bacterial/analysis , Borrelia/immunology , Enzyme-Linked Immunosorbent Assay/methods , Immunoblotting/methods , Lyme Neuroborreliosis/diagnosis , Adolescent , Adult , Aged , Antibodies, Bacterial/blood , Borrelia/isolation & purification , Chemokine CXCL13/analysis , Chemokine CXCL13/immunology , Female , Humans , Lyme Neuroborreliosis/blood , Lyme Neuroborreliosis/cerebrospinal fluid , Lyme Neuroborreliosis/microbiology , Male , Middle Aged , Young Adult
12.
Turk J Med Sci ; 52(5): 1697-1703, 2022 Apr.
Article in English | MEDLINE | ID: mdl-36422475

ABSTRACT

BACKGROUND: Antinuclear antibodies (ANA) and antimitochondrial antibodies (AMA) have essential markers for the diagnosis of autoimmune hepatitis (AIH) and primary biliary cholangitis (PBC). These autoantibodies are detecting different laboratory methods. In this study, we studied the diagnostic performance of used methods in detecting ANA and AMA. METHODS: The autoantibody profiles of patients with AIH and PBC groups were analyzed with the indirect immunofluorescence test (IIF) and liver-specific antigens containing immunoblot test (IB). RESULTS: There were 45 (87%) women in the study group and 8 (53%) women in the control group. The mean age of the patients was 50.5 ± 14.21 years old. The serum ALT and AST levels were higher in AIH, and ALP, GGT, and Ig M were higher in PBC. IIF test results among AIH/PBC groups; there was no difference in overall ANA positivity (p: 0.078). AMA was negative in all patients with AIH but positive in 83.3% of patients with PBC. IB test results among AIH/PBC groups; antibodies against PDGH, LKM-1, and Scl-70 were not observed in any patient with AIH/PBC. Except for M2 (p: 0.001) and M23E (p: 0.007) antibodies, there was no significant difference in antibodies between groups. Out of five PBC patients with negative AMA by IIF method, one was positive for AMA-M2, two were positive anti-gp210, and three were positive anti-M2-3E, but anti-sp100 was negative in all of them by the IB. DISCUSSION: AIH/PBC has complex associations with different autoantibodies, and some of these antibodies are not readily detected by the IIF test. IB assays with a wide variety of liver-specific antigens may be helpful in the diagnosis (especially in patients with AMA negative PBC) and follow-up in AIH/PBC patients.


Subject(s)
Hepatitis, Autoimmune , Liver Cirrhosis, Biliary , Humans , Female , Adult , Middle Aged , Male , Fluorescent Antibody Technique, Indirect , Liver Cirrhosis, Biliary/diagnosis , Autoantibodies , Hepatitis, Autoimmune/diagnosis , Immunologic Tests , Antibodies, Antinuclear
13.
J Biol Chem ; 295(4): 926-939, 2020 01 24.
Article in English | MEDLINE | ID: mdl-31819006

ABSTRACT

Well-characterized antibody reagents play a key role in the reproducibility of research findings, and inconsistent antibody performance leads to variability in Western blotting and other immunoassays. The current lack of clear, accepted standards for antibody validation and reporting of experimental details contributes to this problem. Because the performance of primary antibodies is strongly influenced by assay context, recommendations for validation and usage are unique to each type of immunoassay. Practical strategies are proposed for the validation of primary antibody specificity, selectivity, and reproducibility using Western blot analysis. The antibody should produce reproducible results within and between Western blotting experiments and the observed effect confirmed with a complementary or orthogonal method. Routine implementation of standardized antibody validation and reporting in immunoassays such as Western blotting may promote improved reproducibility across the global life sciences community.


Subject(s)
Antibodies/metabolism , Blotting, Western , Antibody Specificity/immunology , Cell Line, Tumor , Epitopes/immunology , Fluorescence , Humans , Immunoblotting , Peer Review, Research , Peptides/metabolism , Phosphorylation , Poly(ADP-ribose) Polymerases/metabolism , Protein Processing, Post-Translational , Reproducibility of Results
14.
Glycobiology ; 31(2): 116-125, 2021 02 09.
Article in English | MEDLINE | ID: mdl-32614944

ABSTRACT

Complex glycans play vital roles in many biological processes, ranging from intracellular signaling and organ development to tumor growth. Glycan expression is routinely assessed by the application of glycan-specific antibodies to cells and tissues. However, glycan-specific antibodies quite often show a large number of bands on immunoblots and it is hard to interpret the data when reliable controls are lacking. This limits the scope of glycobiology studies and poses challenges for replication. We sought to resolve this issue by developing a novel strategy that utilizes an immunoreaction enhancing technology to vastly improve the speed and quality of glycan-based immunoblots. As a representative case study, we used chondroitin sulfate glycosaminoglycan (CS-GAG) chains as the carbohydrate target and a monoclonal antibody, CS-56, as the probe. We discovered that preincubation of the antibody with its antigenic CS-GAG chain distinguishes true-positive signals from false-positive ones. We successfully applied this strategy to 10E4, a monoclonal anti heparan sulfate GAGs (HS-GAGs) antibody, where true-positive signals were confirmed by chemical HS-GAG depolymerization on the membrane. This evidence that glycan-specific antibodies can generate clear and convincing data on immunoblot with highly replicable results opens new opportunities for many facets of life science research in glycobiology.


Subject(s)
Chondroitin Sulfates/analysis , Immunoblotting , Animals , Antibodies, Monoclonal/immunology , Chondroitin Sulfates/immunology , HeLa Cells , Humans , Mice , Mice, Inbred C57BL
15.
BMC Infect Dis ; 21(1): 325, 2021 Apr 07.
Article in English | MEDLINE | ID: mdl-33827460

ABSTRACT

BACKGROUND: Rapid and simple serological assays for characterizing antibody responses are important in the current COVID-19 pandemic caused by SARS-CoV-2. Multiplex immunoblot (IB) assays termed COVID-19 IB assays were developed for detecting IgG and IgM antibodies to SARS-CoV-2 virus proteins in COVID-19 patients. METHODS: Recombinant nucleocapsid protein and the S1, S2 and receptor binding domain (RBD) of the spike protein of SARS-CoV-2 were used as target antigens in the COVID-19 IBs. Specificity of the IB assay was established with 231 sera from persons with allergy, unrelated viral infections, autoimmune conditions and suspected tick-borne diseases, and 32 goat antisera to human influenza proteins. IgG and IgM COVID-19 IBs assays were performed on 84 sera obtained at different times after a positive RT-qPCR test from 37 COVID-19 patients with mild symptoms. RESULTS: Criteria for determining overall IgG and IgM antibody positivity using the four SARS-CoV-2 proteins were developed by optimizing specificity and sensitivity in the COVID-19 IgG and IgM IB assays. The estimated sensitivities and specificities of the COVID-19 IgG and IgM IBs for IgG and IgM antibodies individually or for either IgG or IgM antibodies meet the US recommendations for laboratory serological diagnostic tests. The proportion of IgM-positive sera from the COVID-19 patients following an RT-qPCR positive test was maximal at 83% before 10 days and decreased to 0% after 100 days, while the proportions of IgG-positive sera tended to plateau between days 11 and 65 at 78-100% and fall to 44% after 100 days. Detection of either IgG or IgM antibodies was better than IgG or IgM alone for assessing seroconversion in COVID-19. Both IgG and IgM antibodies detected RBD less frequently than S1, S2 and N proteins. CONCLUSIONS: The multiplex COVID-19 IB assays offer many advantages for simultaneously evaluating antibody responses to different SARS-CoV-2 proteins in COVID-19 patients.


Subject(s)
Antibodies, Viral/blood , Antibody Formation , COVID-19/blood , Coronavirus Nucleocapsid Proteins/immunology , Spike Glycoprotein, Coronavirus/immunology , Humans , Immunoblotting , Immunoglobulin G/blood , Immunoglobulin M/blood , Pandemics , Phosphoproteins/immunology , Sensitivity and Specificity , Seroconversion , Serologic Tests
16.
Parasitology ; 148(3): 333-340, 2021 03.
Article in English | MEDLINE | ID: mdl-33092663

ABSTRACT

Serological antibody detection by enzyme-linked immunosorbent assay (ELISA)- and immunoblot-based methods constitutes the best indicator of human Toxocara infection. Nevertheless, the availability of serological tests, particularly western blots (WB), evaluated for sensitivity and specificity is limited. Therefore, an Anti-Toxocara-ELISA immunoglobulin g (IgG) prototype (Proto-ELISA) and an Anti-Toxocara-Westernblot (IgG) prototype (Proto-WB) were evaluated by testing 541 human sera pre-determined for Toxocara infection by an established in-house Anti-Toxocara-ELISA (IH-ELISA). To evaluate sensitivity and specificity of the newly developed ELISA and WB prototypes, results were compared to IH-ELISA and a commercial WB (Com-WB). Compared to the IH-ELISA, a sensitivity of 93.1% (229/246) and a specificity of 94.6% (279/295) of the Proto-ELISA with a Cohen's κ of 0.88 were obtained. The sensitivity of the Proto-WB was 76.7% (240/313) and specificity was 99.6% (227/228) with a Cohen's κ of 0.73 compared to those of Com-WB. A comparison to the IH-ELISA revealed 91.5% (225/246) sensitivity and 94.6% (279/295) specificity of the Proto-WB with a Cohen's κ of 0.86. Cross-reactivity was observed for some samples positive for Ascaris and Trichinella spp. in the Proto-ELISA, Proto-WB and Com-WB. Overall, the evaluated ELISA and WB prototypes showed high sensitivity and specificity, indicating high reliability of these newly developed tests.


Subject(s)
Antigens, Helminth/analysis , Blotting, Western/methods , Enzyme-Linked Immunosorbent Assay/methods , Toxocara/isolation & purification , Toxocariasis/diagnosis , Animals , Larva/growth & development , Toxocara/growth & development
17.
Bioorg Chem ; 117: 105461, 2021 12.
Article in English | MEDLINE | ID: mdl-34753060

ABSTRACT

The effect of ß-carboline motif as cap for HDAC inhibitors containing cinnamic acid as linker and benzamides as zinc binding group was examined in this study. A series of ß-carboline-cinnamide conjugates have been synthesized and evaluated for their HDAC inhibitory activity and in vitro cytotoxicity against different human cancer cell lines. Almost all the compounds exhibited superior HDAC inhibitory activity than the standard drug Entinostat for in vitro enzymatic assay. Among the tested compounds, 7h displayed a noteworthy potency with an IC50 value of 0.70 ± 0.15 µM against HCT-15 cell line when compared to the standard drug Entinostat (IC50 of 3.87 ± 0.62 µM). The traditional apoptosis assays such as nuclear morphological alterations, AO/EB, DAPI, and Annexin-V/PI staining revealed the antiproliferative activity of 7h while depolarization of mitochondrial membrane potential by JC-1 was observed in dose-dependent manner. Cell cycle analysis also unveiled the typical accumulation of cells in G2M phase and sub-G1/S phase arrest. In addition, immunoblot analysis for compound 7h on HCT-15 indicated selective inhibition of the protein expression of class I HDAC 2 and 3 isoforms. Molecular docking analysis of compound 7h revealed that it can prominent binding with the active pocket of the HDAC 2. These finding suggest that the compound 7h can be a promising lead candidate for further investigation in the development of novel anti-cancer drug potentially inhibiting HDACs.


Subject(s)
Antineoplastic Agents/pharmacology , Carbolines/pharmacology , Drug Design , Histone Deacetylase Inhibitors/pharmacology , Histone Deacetylases/metabolism , ortho-Aminobenzoates/pharmacology , Animals , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Carbolines/chemistry , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Survival/drug effects , Dose-Response Relationship, Drug , Drug Screening Assays, Antitumor , Histone Deacetylase Inhibitors/chemical synthesis , Histone Deacetylase Inhibitors/chemistry , Humans , Mice , Models, Molecular , Molecular Structure , Structure-Activity Relationship , ortho-Aminobenzoates/chemistry
18.
Acta Derm Venereol ; 101(3): adv00420, 2021 Mar 23.
Article in English | MEDLINE | ID: mdl-33686442

ABSTRACT

Epidermolysis bullosa acquisita is a pemphigoid disease characterized by autoantibodies against type VII collagen. This study compared the sensitivity and specificity of 6 diagnostic assays: type VII collagen non-collagenous domains enzyme-linked immunoassay (NC1/2 ELISA) (MBL, Nagoya, Japan); type VII collagen NC1 ELISA (Euroimmun, Lübeck, Germany); indirect immunofluorescence (IF) microscopy test based on the expression of recombinant NC1 in a human cell line (NC1 BIOCHIP®; Euroimmun); full-length recombinant type VII collagen ELISA; immunoblotting with full-length type VII collagen in the extract of human dermis; and immunoblotting with recombinant NC1. Immunoblotting with recombinant NC1 showed a sensitivity of 93.1% and specificity of 100%, follow-ed by NC1 BIOCHIP® (sensitivity, 89.1%; specificity, 100%), immunoblotting with human dermis (sensitivity, 87.1%; specificity 100%), NC1-ELISA (sensitivity 82.2%; specificity 98.6%), NC1/NC2 ELISA (sensitivity 88.1%; specificity 93.3%), and full-length type VII collagen ELISA (sensitivity 80.2%; specificity 93.8%).


Subject(s)
Epidermolysis Bullosa Acquisita , Autoantibodies , Collagen Type VII , Epidermolysis Bullosa Acquisita/diagnosis , Fluorescent Antibody Technique, Indirect , Germany , Humans , Japan
19.
Br Poult Sci ; 62(3): 379-386, 2021 Jun.
Article in English | MEDLINE | ID: mdl-33225715

ABSTRACT

1. Turkey production has increased dramatically as genetic selection has succeeded in increasing body weight and muscle yield to fulfil increasing consumer demand. However, producing fast-growing, heavily muscled birds is linked to increased heat stress susceptibility and can result in pale, soft, exudative (PSE) meat. Previous studies indicated that pyruvate dehydrogenase kinase 4 (PDK4) is significantly reduced in PSE samples, suggesting this as a candidate gene associated with the development of this problem.2. The objective of this study was to determine whether pre-market thermal challenge results in PSE meat as a result of differential expression of PDK4. Two genetic lines of turkeys were used in this study; the Randombred Control Line 2 (RBC2) and a commercial line. Turkeys were exposed to a pre-market thermal challenge of 12 h at 35°C followed by 12 h at 27°C for 5 d. Birds were slaughtered and processed according to industry standards. Pectoralis major samples were categorised as PSE or normal based on marinade uptake and cook loss indicators. In the first experiment, the relative expression of pyruvate dehydrogenase (PDH) and the phosphorylation state of PDH in normal and PSE turkey meat were analysed by western blotting. In the second experiment, the same samples were used to measure metabolite levels at 5 min post-mortem, comparing the normal to the PSE samples.3. The results of the first experiment showed that PSE samples had significantly lower total PDH (P = 0.029) compared to normal meat. However, there was no significant difference in the degree of phosphorylation of sites 1, 2 or 3. In the second experiment, there were no significant differences in glycogen, lactate, glycolytic potential or ATP when comparing PSE to control samples.4. These results suggested that a reduction in PDK4 expression alone does not explain the development of PSE meat.


Subject(s)
Chickens , Turkeys , Animals , Hydrogen-Ion Concentration , Meat , Muscle, Skeletal/metabolism , Oxidoreductases/metabolism , Phosphorylation , Pyruvates/metabolism , Turkeys/genetics
20.
Zhonghua Gan Zang Bing Za Zhi ; 29(5): 415-420, 2021 May 20.
Article in Zh | MEDLINE | ID: mdl-34107577

ABSTRACT

Objective: To explore the diagnostic value of anti-HCV and HCV RNA so as to provide an accurate and efficient detection strategy for the diagnosis of HCV in intravenous drug users. Methods: 527 plasma samples from intravenous drug users were collected, and preliminary anti-HCV ELISA screening test was performed. A recombinant immunoblot assay (RIBA) was used as confirmatory assay for reactive antibody samples. All samples were tested for HCV RNA, followed by analysis of anti-HCV screening test, RIBA and HCV nucleic acid test results. Results: Anti-HCV ELISA results were reactive in 386 out of 527 intravenous drug users and non-reactive in 141. Among the 386 reactive antibody samples detected by RIBA, 370 cases were anti-HCV positive, 6 cases were anti-HCV indeterminate and 10 cases were anti-HCV negative. Anti-HCV ELISA and RIBA positive coincidence detection rate was 95.85% (370/386), and 70.21% (370/527) among intravenous drug users. HCV RNA was negative in all 10 anti-HCV RIBA non-reactive samples. 376 anti-HCV RIBA-positive and indeterminate samples were tested for HCV RNA, of which 56.93% (300/527) were current HCV infection, and 14.42% (76/527) were past HCV infection. Among 141 anti-HCV ELISA negative samples, the residual risk by anti-HCV ELISA screening for HCV RNA was 1.52% (8/527). HCV viral load distribution among intravenous drug users showed that the high viral load value (>10(7) IU/ml) and low viral load values (< 10(2) IU/ml) accounted for 1.95% and 2.27%, respectively, while the samples with viral load value of 1×10(2) ~ 1×10(7) IU/ mL accounted for 95.78% (295/308), and were mainly distributed in 1×10(5) ~ 1×10(6) IU/ml (37.99%). ELISA + RIBA + NAT assay detection strategies had differentiated 300 cases of current HCV infection, 76 cases of past HCV infection and 10 cases of false positive anti-HCV results, while ELISA+NAT assay detection strategies had only detected 300 cases of current HCV infection. However, of the 386 positive subjects screened for antibodies, 10 (2.59%) were undifferentiated false positives. Conclusion: Intravenous drug users are the high-risk population of HCV infection with high prevalence and high viral load. Anti-HCV screening for intravenous drug users will have a certain degree of residual risk. Therefore, anti-HCV ELISA screening and nucleic acid detection strategy can accurately diagnose the current infected patients; however, it cannot distinguish the false positive results of antibody screening.


Subject(s)
Drug Users , Hepatitis C , Substance Abuse, Intravenous , Enzyme-Linked Immunosorbent Assay , Hepacivirus/genetics , Hepatitis C/diagnosis , Hepatitis C Antibodies , Humans , RNA, Viral
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