Removal of signal peptide variants by cation exchange chromatography: A case study.

Signal peptide (SP) is required for secretion of recombinant proteins and typically cleaved by signal peptidase at its C-region to generate the mature proteins. Miscleavage of the SP is reported occasionally, resulting in a truncated- or elongated-terminal sequence. In the present work, we demonstrated that cation exchange (CEX) chromatography is an effective means for removing SP variants with a case study. With the selected resin/conditions, the chromatographic performance is comparable between runs performed at the low end and high end of load density and elution range. The procedure described in this work can be used as a general approach for resin selection and optimization of chromatographic conditions to remove byproducts that bind more strongly than the product to the selected resin.

The degradation of TYR variants derived from Chinese OCA families is mediated by the ERAD and ERLAD pathway.

Oculocutaneous albinism (OCA) is a genetically heterogeneous group of autosomal recessive disorders, which presents with decreased or absent pigmentation in the hair, skin, and eyes. OCA1, as a subtype of OCA, is caused by mutations in the tyrosinase gene (TYR). In this study, we performed in vitro functional analysis of eight TYR variants (one frameshift variant: c.929dupC (p.Arg311Lysfs*7); seven missense variants: c.896G>A (p.Arg299His), c.1234C>A (p.Pro412Thr), c.1169A>G (p.His390Arg), c.937C>A (p.Pro313Thr), c.636A>T (p.Arg212Ser), c.623 T>G (p.Leu208Arg), c.1325C>A (p.Ser442Tyr)) identified in Chinese OCA families. TYR plasmids were transfected into HEK 293 T cells to explore the effects of TYR variants on their processing, protein expression, activity, and degradation. The results showed that all eight variants caused TYR to be retained in the endoplasmic reticulum (ER), processing was blocked, and TYR activity almost disappeared; the frameshift variant caused the size of the TYR protein to be reduced by about 30KD, and the protein expression of the remaining seven missense variants was reduced; the ER-associated degradation (ERAD) pathway mediates the degradation of TYR variants that occur on the Tyrosinase copper-binding domain, while the degradation of TYR variants that are not located on that domain may be mediated by a new degradation pathway--ER-to-lysosome-associated degradation (ERLAD). In summary, TYR variants affected their protein processing and activity, and may also induce ER stress and trigger degradation through the ERLAD pathway in addition to the ERAD degradation pathway, providing new insights into the potential pathogenic mechanism for OCA1 caused by TYR variants.

Genomic Pipeline for Analysis of Mutational Events in Bacteria.

Unveiling the strategies of bacterial adaptation to stress constitute a challenging area of research. The understanding of mechanisms governing emergence of resistance to antimicrobials is of particular importance regarding the increasing threat of antibiotic resistance on public health worldwide. In the last decades, the fast democratization of sequencing technologies along with the development of dedicated bioinformatical tools to process data offered new opportunities to characterize genomic variations underlying bacterial adaptation. Thereby, research teams have now the possibility to dive deeper in the deciphering of bacterial adaptive mechanisms through the identification of specific genetic targets mediating survival to stress. In this chapter, we proposed a step-by-step bioinformatical pipeline enabling the identification of mutational events underlying biocidal stress adaptation associated with antimicrobial resistance development using Escherichia marmotae as an illustrative model.

SCN1A intronic variants impact on Nav1.1 protein expression and sodium channel function, and associated with epilepsy phenotypic severity.

High-throughput sequencing has identified numerous intronic variants in the SCN1A gene in epilepsy patients. Abnormal mRNA splicing caused by these variants can lead to significant phenotypic differences, but the mechanisms of epileptogenicity and phenotypic differences remain unknown. Two variants, c.4853-1 G>C and c.4853-25 T>A, were identified in intron 25 of SCN1A, which were associated with severe Dravet syndrome (DS) and mild focal epilepsy with febrile seizures plus (FEFS+), respectively. The impact of these variants on protein expression, electrophysiological properties of sodium channels and their correlation with epilepsy severity was investigated through plasmid construction and transfection based on the aberrant spliced mRNA. We found that the expression of truncated mutant proteins was significantly reduced on the cell membrane, and retained in the cytoplasmic endoplasmic reticulum. The mutants caused a decrease in current density, voltage sensitivity, and an increased vulnerability of channel, leading to a partial impairment of sodium channel function. Notably, the expression of DS-related mutant protein on the cell membrane was higher compared to that of FEFS+-related mutant, whereas the sodium channel function impairment caused by DS-related mutant was comparatively milder than that caused by FEFS+-related mutant. Our study suggests that differences in protein expression levels and altered electrophysiological properties of sodium channels play important roles in the manifestation of diverse epileptic phenotypes. The presence of intronic splice site variants may result in severe phenotypes due to the dominant-negative effects, whereas non-canonical splice site variants leading to haploinsufficiency could potentially cause milder phenotypes.

Rare RNF213 variants is related to early-onset intracranial atherosclerosis: A Chinese community-based study.

BACKGROUND: The relationship between rare variants in Ring finger protein 213 (RNF213) and intracranial atherosclerosis (ICAS) remained unelucidated. Using whole-exome sequencing (WES) and high-resolution magnetic resonance imaging (HR-MRI), this study aimed at investigating the association between rare RNF213 variants and ICAS within a Chinese community-dwelling population. METHODS: The present study included 821 participants from Shunyi cohort. Genetic data of rare RNF213 variants were acquired by WES and were categorized by functional domains. Intracranial and extracranial atherosclerosis were assessed by brain HR-MRI and carotid ultrasound, respectively. Logistic regression and generalized linear regression were applied to evaluate the effects of rare RNF213 variants on atherosclerosis. Stratification by age were conducted with 50 years old set as the cutoff value. RESULTS: Ninety-five participants were identified as carriers of rare RNF213 variants. Carotid plaques were observed in 367 (44.7 %) participants, while ICAS was identified in 306 (37.3 %). Rare variants of RNF213 was not associated with ECAS. Employing HR-MRI, both the presence of rare variants (ß = 0.150, P = 0.025) and numerical count of variants (ß = 0.182, P = 0.003) were significantly correlated with ICAS within the group of age ≤50 years. Both variant existence (ß = 0.154, P = 0.014) and variant count (ß = 0.188, P = 0.003) were significantly associated with plaques in middle cerebral arteries within younger subgroup, rather than basilar arteries. Furthermore, a significant association was observed between variants that located outside the N-arm domain and ICAS in the younger subgroup (OR = 2.522, P = 0.030). Statistical results remained robust after adjusted for age, gender, and cardiovascular risk factors. CONCLUSIONS: Rare variants of RNF213 is associated with age-related ICAS in general Chinese population, highlighting the potential role of RNF213 as a genetic contributor to early-onset ICAS.

A head-to-head comparison of humoral and cellular immune responses of five COVID-19 vaccines in adults in China.

Introduction: Various COVID-19 vaccine trials have shown that vaccines can successfully prevent symptomatic cases of COVID-19 and death. Head-to-head comparisons help to better understand the immune response characteristics of different COVID-19 vaccines in humans. Methods: We randomly selected 20 participants from each of five ongoing Phase II trials of COVID-19 vaccines. Here, SARS-CoV 2-specific immune responses to DNA vaccine (INO-4800), mRNA vaccine (BNT162b2), Adenovirus-vectored vaccine (CONVIDECIA), Protein subunit vaccine (Recombinant COVID- 19 Vaccine (Sf9 Cells)), Inactivated Vaccine (KCONVAC) were examined longitudinally in healthy adults between Jan 15, 2021 and July 5, 2021 for 6 months. RBD-IgG titres were detected by ELISA, neutralising antibody titer were detected by pseudoviral neutralization and immune cell response were detected by flow cytometry. Results: At the first visit (V1), 100% of individuals who received the BNT162b2, CONVIDECIA, or KCONVAC vaccines experienced seroconversion of neutralizing and binding antibodies in the serum. Except for the Recombinant COVID-19 Vaccine (Sf9 Cells) vaccine having the highest neutralizing antibody GMT at the second visit (although there was no statistically significant difference in geometric mean titers between V1 and V2), the rest of the vaccines had the highest levels of binding antibodies and neutralizing antibodies at V1. The neutralizing antibodies GMT of all vaccines showed a significant decrease at V3 compared to V1. The neutralizing antibody GMT against the omicron variant of all vaccines at V1 showed a significant decrease compared to the wild strain. We observed statistically significant differences in Tcm cells and RBD-specific memory B cells among various vaccines. Discussion: BNT162b2 (mRNA vaccine) exhibits the highest antibody levels among the five vaccines evaluated, regardless of whether the target is the wild-type virus or its variants. However, its cellular immune response may be weaker compared to CONVIDECIA (adenovirus type 5 vector vaccine).

The evolutionary features and roles of single nucleotide variants and charged amino acid mutations in influenza outbreaks during NPI period.

The epidemic and outbreaks of influenza B Victoria lineage (Bv) during 2019-2022 led to an analysis of genetic, epitopes, charged amino acids and Bv outbreaks. Based on the National Influenza Surveillance Network (NISN), the Bv 72 strains isolated during 2019-2022 were selected by spatio-temporal sampling, then were sequenced. Using the Compare Means, Correlate and Cluster, the outbreak data were analyzed, including the single nucleotide variant (SNV), amino acid (AA), epitope, evolutionary rate (ER), Shannon entropy value (SV), charged amino acid and outbreak. With the emergence of COVID-19, the non-pharmaceutical interventions (NPIs) made Less distant transmission and only Bv outbreak. The 2021-2022 strains in the HA genes were located in the same subset, but were distinct from the 2019-2020 strains (P < 0.001). The codon G → A transition in nucleotide was in the highest ratio but the transversion of C → A and T → A made the most significant contribution to the outbreaks, while the increase in amino acid mutations characterized by polar, acidic and basic signatures played a key role in the Bv epidemic in 2021-2022. Both ER and SV were positively correlated in HA genes (R = 0.690) and NA genes (R = 0.711), respectively, however, the number of mutations in the HA genes was 1.59 times higher than that of the NA gene (2.15/1.36) from the beginning of 2020 to 2022. The positively selective sites 174, 199, 214 and 563 in HA genes and the sites 73 and 384 in NA genes were evolutionarily selected in the 2021-2022 influenza outbreaks. Overall, the prevalent factors related to 2021-2022 influenza outbreaks included epidemic timing, Tv, Ts, Tv/Ts, P137 (B → P), P148 (B → P), P199 (P → A), P212 (P → A), P214 (H → P) and P563 (B → P). The preference of amino acid mutations for charge/pH could influence the epidemic/outbreak trends of infectious diseases. Here was a good model of the evolution of infectious disease pathogens. This study, on account of further exploration of virology, genetics, bioinformatics and outbreak information, might facilitate further understanding of their deep interaction mechanisms in the spread of infectious diseases.

A Rare Case of Granulicatella adiacens Gallbladder Abscess Associated With Gallbladder Adenocarcinoma: Diagnostic and Therapeutic Challenges.

Granulicatella adiacens, a nutritionally variant streptococcus, is part of the normal oral, gastrointestinal, and urogenital flora. It is associated with bacteremia, infectious endocarditis, and, rarely, bone and joint infections. G. adiacens infections also tend to have high mortality due to diagnostic challenges and antibiotic resistance. Few case reports have documented its role in abscess formation. Here, we report the first known case of G. adiacens causing a gallbladder abscess in a patient with gallbladder carcinoma (GBC), a rare but aggressive cancer. Enhanced awareness and improved diagnostic methods are needed to manage such infections and understand their underlying mechanisms, particularly in immunocompromised patients with malignancies.

Novel autosomal recessive SINO syndrome-associated KIDINS220 variants provide insight into the genotype-phenotype correlation.

Background: KIDINS220 encodes a transmembrane scaffold protein, kinase D-interacting substrate of 220 kDa, that regulates neurotrophin signaling. Variants in KIDINS220 have been linked to spastic paraplegia, intellectual disability, nystagmus, and obesity (SINO) syndrome or prenatal fatal cerebral ventriculomegaly and arthrogryposis (VENARG). This study aimed to investigate the genotype-phenotype correlation of pathogenic KIDINS220 variants. Methods: We performed whole-exome sequencing on a patient with SINO syndrome and epilepsy. Identified pathogenic variants were confirmed using Sanger sequencing and evaluated with in silico tools. A comprehensive literature review was conducted to analyze the genetic and phenotypic data of both the newly diagnosed patient and previously reported cases with KIDINS220 variants. Results: We identified novel compound heterozygous variants in KIDINS220, c.1556C > T (p.Thr519Met) and c.2374C > T (p.Arg792*), in the patient. Our analysis revealed that biallelic loss-of-function variants in KIDINS220 are associated with VENARG or autosomal recessive SINO (AR-SINO), whereas carboxy-terminal truncated variants that escape nonsense-mediated mRNA decay and lack amino acid residues 1507-1529 are linked to autosomal dominant SINO (AD-SINO). Patients with AR-SINO exhibit more severe clinical features compared to those with AD-SINO. Conclusions: Our study expands the spectrum of KIDINS220 variants associated with AR-SINO and provides a valuable genotype-phenotype correlation for pathogenic KIDINS220 variants.

Novel homozygous missense variants in MED27 associated with neurodevelopmental disorder: Clinical and pathogenetic research.

Background: Neurodevelopmental disorder with spasticity, cataracts, and cerebellar hypoplasia (NEDSCAC), induced by MED27 gene, is an autosomal recessive rare disorder characterized by widespread developmental delay with varying degrees of intellectual impairment. Other symptoms include limb spasticity, cataracts, and cerebellar hypoplasia. So far there have been limited reports on NEDSCAC. Methods: In this study, we conducted genetic testing on a child presenting with developmental delay as the primary clinical feature. The genetic test results indicated the presence of novel homozygous missense variants c.74G > A, p.(Arg25His) in the MED27 gene. In vitro functional validation experiments, including plasmid construction and cell transfection, Western blotting, and molecular dynamics structural modeling, were performed on the MED27 Arg25His variant. Results: The results demonstrated a significant reduction in protein expression of MED27 Arg25His and indicated may weaken the interaction force between the MED27 subunit and MED14 subunit. Conclusions: This study expands our understanding of MED27 gene variants and their associated clinical phenotypes. Additionally, it contributes to the investigation of the potential pathogenesis of NEDSCAC caused by MED27 gene variants.

Human induced pluripotent stem cell line (FDHSi005-A) derived from a patient with a deep intronic variant in the GNE gene.

GlcNAc2-epimerase myopathy is a rare autosomal recessive myopathy characterized by distal involvement in the lower extremities. Our study reprogrammed human-induced pluripotent stem cells from peripheral blood mononuclear cells of a patient with GNE gene deep intronic variant c.862 + 870C>T and c.478C>T compound heterozygous mutations that co-segregated with the disease. The generated iPSCs express pluripotent cell markers with no mycoplasma contamination. Additionally, these iPSCs demonstrated pluripotency, the capacity to differentiate into the three germ layers, and maintained normal karyotypes. Importantly, we identified that these iPSCs possess the same specific mutations as the patient, making them a robust model for studying GNE myopathy and developing potential therapeutic interventions.

The Gly103Arg variant in hereditary transthyretin amyloidosis.

Background: Hereditary transthyretin amyloidosis (ATTRv) is an autosomal dominant inherited systematic disease primarily affecting the peripheral and autonomic nervous system, heart, eyes and kidney. Over 140 variants have been identified worldwide, with the Gly103Arg variant reported exclusively in China. This variant is characterized by early onset eye manifestations, making accurate and timely diagnosis difficult. Therefore, we conducted a case study and literature review to investigate the clinical characteristics of the Gly103Arg variant in hereditary transthyretin amyloidosis. Methods: We identified three patients and an asymptomatic carrier in a four-generation family by sequencing the TTR gene. The proband underwent a lumbar puncture, electromyography, abdominal fat biopsy, among other tests. Case reports of Gly103Arg variant were retrieved through a literature search for an analysis of clinical characteristics. Results: The study included clinical data of 44 patients. Our literature review collected data on 41 patients and the present report supplied 3 patients with the Gly103Arg variant. The mean age at onset was 39.1 ± 4.27 years (range 30-47 years) with a female ratio of 52.3%. All cases were reported in China, predominantly in southern regions, especially Yunan and Guizhou Provinces. The initial manifestation was blurred vision, except for one case presenting with numbness in the upper extremities. All of them had vitreous opacity; 17 cases had peripheral neuropathy,6 cases had autonomic neuropathy, and 3 cases had cardiopathy. No disease-related deaths have been reported to date. Conclusion: The Gly103Arg variant is unique to the Chinese population, frequently occurring in southern China. The main clinical manifestations are blurred vision, vitreous opacity, and neuropathy, with cardiopathy being rare. ATTRv should be considered if a patient diagnosed with CIDP does not respond to related therapy. Abdominal fat biopsy is a convenient and accurate diagnostic method.

Comparative 60-day effectiveness of bivalent versus monovalent mRNA vaccines in Shelby County: a population-level analysis.

Background: Two monovalent mRNA vaccines, available in December 2020, were demonstrated to have high efficacy against both the original SARS-CoV-2 strain and variants circulating through the summer and into the fall of 2021. In the context of the Omicron/BA.1 variant, which was predominant from late fall 2021 into winter of 2022 in the United States, and subsequent Omicron subvariants that have been predominant thereafter, vaccine effectiveness of the monovalent mRNA vaccine option is attenuated. Objectives: We aim to investigate the relative effectiveness of the bivalent booster compared to the monovalent booster against SARS-CoV-2 infection in the 60 days following administration in Shelby County, TN. Design: This observational population-based cohort study utilizes COVID-19 surveillance data to identify adults who were vaccinated with a monovalent booster dose between August 1, 2022 and August 30, 2022 or a bivalent booster dose between September 1, 2022 and September 30, 2022. Both groups were followed for COVID-19 status for 60 days from their administration date. Methods: We calculated incidence rates with 95% confidence intervals and propensity-adjusted hazard ratios with 95% confidence intervals of COVID-19 diagnosis in the 60 days following administration of the booster dose between the bivalent group and the monovalent group. Stratified analysis was conducted by age group (18-34, 35-64, and 65+ years old). Results: The incidence of reported SARS-CoV-2 infection was substantially higher for those who received the monovalent booster, across age groups. Overall, we observed a 51% lower hazard of infection during the study period among those who received the bivalent booster, compared to the monovalent booster. Conclusion: These results support and extend prior findings that the bivalent booster dose may be more effective in preventing infection against the Omicron sub-variants of SARS-CoV-2.

In silico analysis for SARS-CoV-2 detection in the context of genetic variability of the Algerian omicron variant.

The risk to public health conferred by the Omicron variant is still not completely clear, although its numerous gene mutations have raised concerns regarding its potential for increased transmissibility and immune escape. In this study, we test the compatibility of the different primers and probes available in different commercial kits sold internationally with all the sequences of SARS-CoV-2 analyzed in Algeria until March 2023. The Algerian SARS-CoV-2 Omicron variant sequences were aligned with the Muscle tool using Genious software. We also used primers and probes sequences of seven international RT-qPCR kits; CDC China, Charite Germany, HKU Hong Kong, NIH Thailand, NIID Japan, CDC US, and Pasteur Institute. We used the primer check v2.0 developed by VIROSCIENCE LAB, To identify the different mutations located at the level of primers and probes about the Algerian sequences of SARS-CoV2. Statistical tests were carried out by calculating the x 2 test. We found regarding the Forward primer sequences that the two Thailand and Japan kits are less specific to the Algerian version of the SARS-CoV-2 Omicron variant genome compared to the other kits (p=10-6). Furthermore, regarding the Reverse primers and fluorescent Probes, the three kits; Thailand, Japan, and CDC US; are less effective (p=10-6). Regarding all primers and probes, this work allowed us to conclude that the four RT-qPCR kits: CDC China, Charite Germany, NHD Hong Kong, and Pasteur Institute seem to be more specific for the Algerian omicron genome detection and therefore for diagnosis of COVID-19 in Algeria.

Claudin 1, 4, 6 and 18 isoform 2 as targets for the treatment of cancer (Review).

The 24 claudin (CLDN) genes in the human genome encode 26 representative CLDN family proteins. CLDNs are tetraspan­transmembrane proteins at tight junctions. Because several CLDN isoforms, such as CLDN6 and CLDN18.2, are specifically upregulated in human cancer, CLDN­targeting monoclonal antibodies (mAbs), antibody­drug conjugates (ADCs), bispecific antibodies (bsAbs) and chimeric antigen receptor (CAR) T cells have been developed. In the present review, CLDN1­, 4­, 6­ and 18.2­targeting investigational drugs in clinical trials are discussed. CLDN18.2­directed therapy for patients with gastric and other types of cancer is the most advanced area in this field. The mouse/human chimeric anti­CLDN18.2 mAb zolbetuximab has a single­agent objective response rate (ORR) of 9%, and increases progression­free and overall survival in combination with chemotherapy. The human/humanized anti­CLDN18.2 mAb osemitamab, and ADCs AZD0901, IBI343 and LM­302, with single­agent ORRs of 28­60%, have been tested in phase III clinical trials. In addition, bsAbs, CAR T cells and their derivatives targeting CLDN4, 6 or 18.2 are in phase I and/or II clinical trials. AZD0901, IBI343, zolbetuximab and the anti­CLDN1 mAb ALE.C04 have been granted fast track designation or priority review designation by the US Food and Drug Administration.

A content analysis of parents' reflections on pathogenic and uncertain pediatric oncology germline sequencing results.

Germline genomic sequencing is increasingly integrated into pediatric cancer care, with pathogenic cancer-predisposing variants identified among 5-18% of affected children and variants of uncertain significance (VUS) in up to 70%. Given the potential medical implications for children and their families, parents' psychosocial responses to learning results are important to understand. Parents of children with cancer who learned their children's germline pathogenic or VUS results following paired tumor and germline genomic sequencing described their cognitive and affective responses to results in an open-ended write-in question after disclosure (M = 10 months post-disclosure; range = 1-28). Responses were coded and categorized using content analysis, then compared across results using chi-square and Fisher's exact test. Parents of children with pathogenic (n = 9), VUS (n = 52), and pathogenic plus VUS results (n = 9) described negative emotions, positive reactions, mixed emotions (i.e., positive and negative emotions), and neutral reactions. Negative emotions were described significantly more frequently with pathogenic results than VUS only (χ2 = 5.19; p = .02), with peace of mind and empowerment only described for those with VUS. Parents also described approach(es) to coping (e.g., faith, plan of action) and reactions specific to the uncertainty of VUS (e.g., disappointment at no explanation for cancer etiology). A subset with VUS described decreasing worry/distress with increased understanding of results, whereas others displayed misconceptions regarding VUS. Screening for emotional adjustment is warranted for parents of children with cancer receiving pathogenic germline results, and screening for understanding is warranted with VUS. Findings highlight the importance of pre-and posttest genetic counseling.

A comprehensive genotype-phenotype study in 203 individuals with retinoblastoma.

Retinoblastoma is the most common intraocular tumor in children and is caused by biallelic inactivation of the RB1 gene. The identification of RB1 germline variants in patients with retinoblastoma and their families is critical for early diagnosis and prevention. In this study, genetic testing was conducted on the genomic DNA of 203 patients with retinoblastoma using a combined approach of direct sequencing and multiplex ligation-dependent probe amplification (MLPA) assays for genotype-phenotype correlation studies. Sixty-five germline variants were identified in 80 of the 203 patients, with 67 bilateral and 13 unilateral retinoblastoma cases. The variant detection rates in the bilateral and unilateral cases were 88% and 10%, respectively. Eighteen novel variants were identified. Variants were classified according to their presence, mutation pattern, location, molecular consequences, and pathogenicity. Subsequently, the genotypes and phenotypes of the 203 patients were evaluated. Variants were associated with age at diagnosis (p < 0.001), laterality (p < 0.001), and tumor size (p = 0.010). The molecular consequences of the variants were related to laterality (p < 0.001) and tumor size (p = 0.001). The pathogenicity of the variants was associated with age at diagnosis (p = 0.001), laterality (p = 0.0212), treatment response (p = 0.0470), and tumor size (p = 0.002). These results suggest that patient phenotypes are associated with the inherent characteristics of germline RB1 variants. These findings indicate the potential application of genetic testing results in clinical practice.

A colorimetric reverse-transcription loop-mediated isothermal amplification method targeting the L452R mutation to detect the Delta variant of SARS-CoV-2.

The rapid spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has triggered global difficulties for both individuals and economies, with new variants continuing to emerge. The Delta variant of SARS-CoV-2 remains most prevalent worldwide, and it affects the efficacy of coronavirus disease 2019 (COVID-19) vaccination. Expedited testing to detect the Delta variant of SARS-CoV-2 and monitor viral transmission is necessary. This study aimed to develop and evaluate a colorimetric reverse-transcription loop-mediated isothermal amplification (RT-LAMP) technique targeting the L452R mutation in the S gene for the specific detection of the Delta variant. In the test, positivity was indicated as a color change from purple to yellow. The assay's 95% limit of detection was 57 copies per reaction for the L452R (U1355G)-specific standard plasmid. Using 126 clinical samples, our assay displayed 100% specificity, 97.06% sensitivity, and 98.41% accuracy in identifying the Delta variant of SARS-CoV-2 compared to real-time RT-PCR. To our knowledge, this is the first colorimetric RT-LAMP assay that can differentiate the Delta variant from its generic SARS-CoV-2, enabling it as an approach for studying COVID-19 demography and facilitating proper effective control measure establishment to fight against the reemerging variants of SARS-CoV-2 in the future.

Epidemiology, clinical characteristics, and outcome of infective endocarditis due to Abiotrophia and Granulicatella in a Tertiary Hospital in China, 2015-2023: a retrospective study.

BACKGROUND: Abiotrophia (ABI) and Granulicatella (GRA) are rare causative pathogens in infective endocarditis (IE). This study aims to describe the epidemiology, clinical characteristics, and outcome of ABI/GRA-IE. The main features of ABI/GRA-IE were compared with Viridans group streptococci (VGS) IE. METHODS: From January 2015 to December 2023, a total of 1531 definite IE in Zhongshan Hospital, Fudan University, Shanghai, China were retrospectively enrolled in this study. Clinical and laboratory data were collected. RESULTS: Forty-five ABI/GRA-IE cases were identified, representing 2.9% of all IE cases in Zhongshan Hospital between 2015 and 2023, compared to 20.1% of VGS-IE. ABI and GRA IE shared similar clinical characteristics. Congenital valvulopathy was reported in 21 (46.7%) ABI/GRA-IE and 85 (28.8%) VGS-IE (P = 0.025). Pulmonary valve was more frequently affected in ABI/GRA-IE (6 [13.3%]) than VGS-IE (7 [2.4%]) (P = 0.002). Congestive heart failure was observed in 30 (66.7%) ABI/GRA-IE and 103 (34.9%) VGS-IE (P < 0.001). Systemic embolization excluding central nervous system (CNS) occurred in 13 (28.9%) ABI/GRA-IE and 39 (13.2%) VGS-IE (P = 0.012). In-hospital mortality was reported as 4.4% in ABI/GRA-IE and 3.7% in VGS-IE (P = 0.854). CONCLUSION: GRA/ABI-IE was approximately one-seventh as prevalent as VGS-IE. Congestive heart failure and systemic embolization (excluding CNS) were more frequent in GRA/ABI-IE compared to VGS-IE. Mortality of ABI/GRA-IE in this study was comparable to that of VGS-IE and lower than previously reported results.

Comprehensive Characterization of a Subfamily of Ca2+-Binding Proteins in Mouse and Human Retinal Neurons at Single-Cell Resolution.

Ca2+-binding proteins (CaBPs; CaBP1-5) are a subfamily of neuronal Ca2+ sensors with high homology to calmodulin. Notably, CaBP4, which is exclusively expressed in rod and cone photoreceptors, is crucial for maintaining normal retinal functions. However, the functional roles of CaBP1, CaBP2, and CaBP5 in the retina remain elusive, primarily due to limited understanding of their expression patterns within inner retinal neurons. In this study, we conducted a comprehensive transcript analysis using single-cell RNA sequencing datasets to investigate the gene expression profiles of CaBPs in mouse and human retinal neurons. Our findings revealed notable similarities in the overall expression patterns of CaBPs across both species. Specifically, nearly all amacrine cell, ganglion cell, and horizontal cell types exclusively expressed CaBP1. In contrast, the majority of bipolar cell types, including rod bipolar (RB) cells, expressed distinct combinations of CaBP1, CaBP2, and CaBP5, rather than a single CaBP as previously hypothesized. Remarkably, mouse rods and human cones exclusively expressed CaBP4, whereas mouse cones and human rods coexpressed both CaBP4 and CaBP5. Our single-cell reverse transcription polymerase chain reaction analysis confirmed the coexpression CaBP1 and CaBP5 in individual RBs from mice of either sex. Additionally, all three splice variants of CaBP1, primarily L-CaBP1, were detected in mouse RBs. Taken together, our study offers a comprehensive overview of the distribution of CaBPs in mouse and human retinal neurons, providing valuable insights into their roles in visual functions.