Comparison of six antibody assays and two combination assays for COVID-19

[Introduction] In this work, six SARS-CoV-2-specific antibody assays were evaluated, namely, two pan-immunoglobulin (pan-Ig) assays [Roche Elecsys Anti-SARS-CoV-2 (named "Elecsys" in this study) and the PerkinElmer SuperFlex™ Anti-SARS-CoV-2 Ab Assay (SuperFlex_Ab)], two IgM assays [SuperFlex™ Anti-SARS-CoV-2 IgM Assay (SuperFlex_IgM) and YHLO iFlash-SARS-CoV-2 IgM (iFlash_IgM)], and two IgG assays [SuperFlex™ Anti-SARS-CoV-2 IgG Assay (SuperFlex_IgG) and iFlash-SARS-CoV-2 IgG (iFlash_IgG)]. Combination assays of SuperFlex™ (SuperFlex_any) and iFlash (iFlash_any) were also evaluated. [Methods] A total of 438 residual serum samples from 54 COVID-19 patients in the COVID-19 group and 100 samples from individuals without evidence of SARS-CoV-2 infection in the negative control group were evaluated. [Results] In the early stage of COVID-19 infection, within 14 days of symptom onset, the seropositive rate was lower than that of the late stage 15 days after onset (65.4% vs 99.6%). In the total period, the pan-Ig and IgG assays had higher sensitivity (90.8–95.3%) than the IgM assays (36.5–40.7%). SuperFlex_Ab and SuperFlex_any had higher sensitivity than Elecsys and SuperFlex_IgG (p < 0.05). The specificity of all the assays was 100%, except for SuperFlex_IgM (99.0%). The concordance rate between each assay was higher (96.4–100%) in the late stage than in the early stage (77.4–98.1%). [Conclusion] For the purpose of COVID-19 diagnosis, antibody testing should be performed 15 days after onset. For the purpose of epidemiological surveillance, highly sensitive assays should be used as much as possible, such as SuperFlex_Ab, iFlash_IgG and their combination. IgM assays were not suitable for these purposes

Healing of two‐wall intra‐bony defects treated with a novel EMD‐liquid—A pre‐clinical study in monkeys

AimTo investigate the effect of a novel enamel matrix derivative formulation (EMD‐liquid or Osteogain) combined with an absorbable collagen sponge (ACS) on periodontal wound healing in intra‐bony defects in monkeys.Materials and MethodsChronic two‐wall intra‐bony defects were created at the distal aspect of eight teeth in three monkeys (Macaca fascicularis). The 24 defects were randomly assigned to one of the following treatments: (i) open flap debridement (OFD) + ACS alone, (ii) OFD + Emdogain + ACS (Emdogain/ACS), (iii) OFD + Osteogain + ACS (Osteogain/ACS) or (iv) OFD alone. At 4 months, the animals were euthanized for histologic evaluation.ResultsOsteogain/ACS resulted in more consistent formation of cementum, periodontal ligament and bone with limited epithelial proliferation compared to OFD alone, Emdogain/ACS and OFD + ACS. Among the four treatment groups, the Osteogain/ACS group demonstrated the highest amount of regenerated tissues. However, complete periodontal regeneration was not observed in any of the defects in the four groups.ConclusionsThe present findings indicate that in two‐wall intra‐bony defects, reconstructive surgery with Osteogain/ACS appears to be a promising novel approach for facilitating periodontal wound healing/regeneration, thus warranting further clinical testing.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141785/1/jcpe12825.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/141785/2/jcpe12825_am.pd

Effects of EMD liquid (Osteogain) on periodontal healing in class III furcation defects in monkeys

AimTo evaluate the effect of a novel liquid carrier system of enamel matrix derivative (Osteogain) soaked on an absorbable collagen sponge (ACS) upon periodontal wound healing/regeneration in furcation defects in monkeys.Materials and MethodsThe stability of the conventional enamel matrix derivative (Emdogain) and Osteogain adsorbed onto ACS was evaluated by ELISA. Chronic class III furcation defects were created at teeth 36, 37, 46, 47 in three monkeys (Macaca fascicularis). The 12 defects were assigned to one of the following treatments: (1) open flap debridement (OFD) + ACS, (2) OFD+Emdogain/ACS, (3) OFD+Osteogain/ACS, and (4) OFD alone. At 16 weeks following reconstructive surgery, the animals were killed for histological evaluation.ResultsA 20–60% significantly higher amount of total adsorbed amelogenin was found for ACS‐loaded Osteogain when compared to Emdogain. The histomorphometric analysis revealed that both approaches (OFD + Emdogain/ACS and OFD + Osteogain/ACS) resulted in higher amounts of connective tissue attachment and bone formation compared to treatment with OFD + ACS and OFD alone. Furthermore, OFD + Osteogain/ACS group showed higher new attachment formation, cementum, and new bone area.ConclusionsWithin their limits, the present data indicate that Osteogain possesses favourable physicochemical properties facilitating adsorption of amelogenin on ACS and may additionally enhance periodontal wound healing/regeneration when compared to Emdogain.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136308/1/jcpe12663.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136308/2/jcpe12663_am.pd

Histological evaluation of nonsurgical periodontal treatment with and without the use of sodium hypochlorite / amino acids and cross-linked hyaluronic acid gels in dogs.

OBJECTIVES To evaluate periodontal wound healing following scaling and root planing (SRP) in conjunction with the application of sodium hypochlorite/amino acids and cross-linked hyaluronic acid (xHyA) gels in dogs. MATERIALS AND METHODS In four beagle dogs, 2-wall intrabony defects were created and metal strips were placed around the teeth. Clinical parameters were measured 4 weeks after plaque accumulation. The experimental root surfaces were subjected to SRP with either the subgingival application of a sodium hypochlorite/amino acid gel and a xHyA gel (test group) or SRP alone (control group) using a split-mouth design. Clinical parameters were re-evaluated at 6 weeks. The animals were sacrificed at 8 weeks for histological analysis. RESULTS The test group showed significant improvements in all clinical parameters compared to the control group. Histologically, the test group exhibited statistically significantly greater new bone formation [i.e., length of newly formed bone, new bone area] compared with the control group (p < 0.05). Furthermore, statistically significantly greater formation of new attachment [i.e., linear length of new cementum adjacently to newly formed bone with inserting collagen fibers] and new cementum was detected in the test group compared with the control group at 8 weeks (p < 0.05 and p < 0.01, respectively). CONCLUSION The adjunctive subgingival application of sodium hypochlorite/amino acid and xHyA gels to SRP offers an innovative novel approach to enhance periodontal wound healing/regeneration. CLINICAL RELEVANCE The present findings have for the first-time shown histologic evidence for periodontal regeneration in support of this novel treatment modality

Cleavage of host cytokeratin-6 by lysine-specific gingipain induces gingival inflammation in periodontitis patients

Background/Purpose. Lysine-specific gingipain (Kgp) is a virulence factor secreted from Porphyromonas gingivalis (P. gingivalis), a major etiological bacterium of periodontal disease. Keratin intermediate filaments maintain the structural integrity of gingival epithelial cells, but are targeted by Kgp to produce a novel cytokeratin 6 fragment (K6F). We investigated the release of K6F and its induction of cytokine secretion. Methods. K6F present in the gingival crevicular fluid of periodontal disease patients and in gingipain-treated rat gingival epithelial cell culture supernatants was measured by matrix-assisted laser desorption/ionization time-of-flight mass spectrometer-based rapid quantitative peptide analysis using BLOTCHIP. K6F in gingival tissues was immunostained, and cytokeratin 6 protein was analyzed by immunofluorescence staining and flow cytometry. Activation of MAPK in gingival epithelial cells was evaluated by immunoblotting. ELISA was used to measure K6F and the cytokines release induced by K6F. Human gingival fibroblast migration was assessed using a Matrigel invasion chamber assay. Results. We identified K6F, corresponding to the C-terminus region of human cytokeratin 6 (amino acids 359–378), in the gingival crevicular fluid of periodontal disease patients and in the supernatant from gingival epithelial cells cultured with Kgp. K6F antigen was distributed from the basal to the spinous epithelial layers in gingivae from periodontal disease patients. Cytokeratin 6 on gingival epithelial cells was degraded by Kgp, but not by Arg-gingipain, P. gingivalis lipopolysaccharide or Actinobacillus actinomycetemcomitans lipopolysaccharide. K6F, but not a scrambled K6F peptide, induced human gingival fibroblast migration and secretion of interleukin (IL)-6, IL-8 and monocyte chemoattractant protein-1. These effects of K6F were mediated by activation of p38 MAPK and Jun N-terminal kinase, but not p42/44 MAPK or p-Akt. Conclusion. Kgp degrades gingival epithelial cell cytokeratin 6 to K6F that, on release, induces invasion and cytokine secretion by human gingival fibroblasts. Thus, Kgp may contribute to the development of periodontal disease

Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae. II: The Second Year (2009-2010)

As an extension of the project in Kato et al. (2009, arXiv:0905.1757), we collected times of superhump maxima for 61 SU UMa-type dwarf novae mainly observed during the 2009-2010 season. The newly obtained data confirmed the basic findings reported in Kato et al. (2009): the presence of stages A-C, as well as the predominance of positive period derivatives during stage B in systems with superhump periods shorter than 0.07 d. There was a systematic difference in period derivatives for systems with superhump periods longer than 0.075 d between this study and Kato et al. (2009). We suggest that this difference is possibly caused by the relative lack of frequently outbursting SU UMa-type dwarf novae in this period regime in the present study. We recorded a strong beat phenomenon during the 2009 superoutburst of IY UMa. The close correlation between the beat period and superhump period suggests that the changing angular velocity of the apsidal motion of the elliptical disk is responsible for the variation of superhump periods. We also described three new WZ Sge-type objects with established early superhumps and one with likely early superhumps. We also suggest that two systems, VX For and EL UMa, are WZ Sge-type dwarf novae with multiple rebrightenings. The O-C variation in OT J213806.6+261957 suggests that the frequent absence of rebrightenings in very short-Porb objects can be a result of sustained superoutburst plateau at the epoch when usual SU UMa-type dwarf novae return to quiescence preceding a rebrightening. We also present a formulation for a variety of Bayesian extension to traditional period analyses.Comment: 63 pages, 77 figures, 1 appendix, Accepted for publication in PASJ, data correctio