Identification of a highly conserved neutralizing epitope within the RBD region of diverse SARS-CoV-2 variants.

The constant emergence of SARS-CoV-2 variants continues to impair the efficacy of existing neutralizing antibodies, especially XBB.1.5 and EG.5, which showed exceptional immune evasion properties. Here, we identify a highly conserved neutralizing epitope targeted by a broad-spectrum neutralizing antibody BA7535, which demonstrates high neutralization potency against not only previous variants, such as Alpha, Beta, Gamma, Delta and Omicron BA.1-BA.5, but also more recently emerged Omicron subvariants, including BF.7, CH.1.1, XBB.1, XBB.1.5, XBB.1.9.1, EG.5. Structural analysis of the Omicron Spike trimer with BA7535-Fab using cryo-EM indicates that BA7535 recognizes a highly conserved cryptic receptor-binding domain (RBD) epitope, avoiding most of the mutational hot spots in RBD. Furthermore, structural simulation based on the interaction of BA7535-Fab/RBD complexes dissects the broadly neutralizing effect of BA7535 against latest variants. Therapeutic and prophylactic treatment with BA7535 alone or in combination with BA7208 protected female mice from the circulating Omicron BA.5 and XBB.1 variant infection, suggesting the highly conserved neutralizing epitope serves as a potential target for developing highly potent therapeutic antibodies and vaccines.

Biparatopic antibody BA7208/7125 effectively neutralizes SARS-CoV-2 variants including Omicron BA.1-BA.5.

SARS-CoV-2 Omicron subvariants have demonstrated extensive evasion from monoclonal antibodies (mAbs) developed for clinical use, which raises an urgent need to develop new broad-spectrum mAbs. Here, we report the isolation and analysis of two anti-RBD neutralizing antibodies BA7208 and BA7125 from mice engineered to produce human antibodies. While BA7125 showed broadly neutralizing activity against all variants except the Omicron sublineages, BA7208 was potently neutralizing against all tested SARS-CoV-2 variants (including Omicron BA.1-BA.5) except Mu. By combining BA7208 and BA7125 through the knobs-into-holes technology, we generated a biparatopic antibody BA7208/7125 that was able to neutralize all tested circulating SARS-CoV-2 variants. Cryo-electron microscopy structure of these broad-spectrum antibodies in complex with trimeric Delta and Omicron spike indicated that the contact residues are highly conserved and had minimal interactions with mutational residues in RBD of current variants. In addition, we showed that administration of BA7208/7125 via the intraperitoneal, intranasal, or aerosol inhalation route showed potent therapeutic efficacy against Omicron BA.1 and BA.2 in hACE2-transgenic and wild-type mice and, separately, effective prophylaxis. BA7208/7125 thus has the potential to be an effective candidate as an intervention against COVID-19.

A Randomized, Double-Blind, Placebo-Controlled, First-in-Human Clinical Trial to Assess Safety, Tolerability, and Pharmacokinetics of LY-CovMab, a Potent Human Neutralizing Antibody Against SARS-CoV-2.

INTRODUCTION: We aimed to evaluate the safety, tolerability, pharmacokinetics, and immunogenicity of a single dose of LY-CovMab in Chinese healthy adults. METHODS: We conducted a phase 1, randomized, dose-escalation, placebo-controlled trial in 42 volunteers, 18-45 years of age, and 40 out of 42 received a single dose of LY-CovMab or placebo with LY-CovMab at a dose of 30 mg, 150 mg, 600 mg, 1200 mg, and 2400 mg. There were ten subjects in each group receiving LY-CovMab or placebo in a 4:1 ratio with the exception that the 30 mg group had two subjects both receiving LY-CovMab. RESULTS: Among the 42 randomized participants, 40 received an injection with 32 administered LY-CovMab and 8 administered placebo. A total of 18 drug-related treatment-emergent adverse events (TEAEs) were reported in 12 subjects (30.0%), including protein urine present (25%, 10/40) and blood creatinine increased (7.5%, 3/40). The incidence of drug-related TEAE in each dosage group was as follows: 150 mg (28.6%, 2/7), 600 mg (25%, 2/8), 1200 mg (14.3%, 1/7), 2400 mg (50%, 4/8), and placebo (37.5%, 3/8). All drug-related TEAEs were grade 1, and most of them were recovering/resolving or recovered/resolved without taking action. The serum exposure of LY-CovMab (Cmax, AUC0-last, AUC0-inf) after intravenous infusion increased in an approximately proportional manner as the dose increased from 150 to 2400 mg. The elimination half-life (t1/2) value did not differ among different dose cohorts and was estimated to be around 28.5 days. CONCLUSIONS: A single dose of LY-CovMab was shown to be safe and well tolerated in Chinese healthy adults. The pharmacokinetic (PK) profiles of LY-CovMab in healthy adults showed typical monoclonal antibody distribution and elimination characteristics. LY-CovMab demonstrated dose proportionality. TRIAL REGISTRATION: ClinicalTrial.gov Identifier NCT04973735.

Two novel human anti-CD25 antibodies with antitumor activity inversely related to their affinity and in vitro activity.

High tumor regulatory T (Treg) cell infiltration is associated with poor prognosis of many cancers. CD25 is highly expressed on tumor Treg cells and is a potential target for Treg deletion. Previously characterized anti-CD25 antibodies appear to have limited efficacy in tumor inhibition. Here we identified two human anti-CD25 antibodies, BA9 and BT942, which did not prevent the activation of IL-2R signaling pathway by IL-2. BT942 had weaker binding and cytotoxic activity to human CD25-expressing cell lines than BA9. But both demonstrated significant tumor growth inhibition in early and late-stage animal cancer models. BT942 resulted in a higher expansion of CD8+ T cells and CD4+ T cells in tumor microenvironment in mouse MC38 model compared to BA9. BT942 also demonstrated significant higher tumor growth inhibition and higher expansion of CD8+ T cells and CD4+ T cells in combination with an anti-PD1 antibody. Pharmacokinetic study of BT942 in cynomolgus monkeys demonstrated a half-life of 206.97 ± 19.03 h. Structural analysis by cryo-EM revealed that BT942 recognizes an epitope on opposite side of the CD25-IL-2 binding site, consistent with no IL-2 signaling blockade in vitro. BT942 appears to be an excellent candidate for cancer immunotherapy.

Structure and function analysis of a potent human neutralizing antibody CA521FALA against SARS-CoV-2.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the ongoing COVID-19 pandemic, which has resulted in more than two million deaths at 2021 February . There is currently no approved therapeutics for treating COVID-19. The SARS-CoV-2 Spike protein is considered a key therapeutic target by many researchers. Here we describe the identification of several monoclonal antibodies that target SARS-CoV-2 Spike protein. One human antibody, CA521FALA, demonstrated neutralization potential by immunizing human antibody transgenic mice. CA521FALA showed potent SARS-CoV-2-specific neutralization activity against SARS-CoV-2 pseudovirus and authentic SARS-CoV-2 infection in vitro. CA521FALA also demonstrated having a long half-life of 9.5 days in mice and 9.3 days in rhesus monkeys. CA521FALA inhibited SARS-CoV-2 infection in SARS-CoV-2 susceptible mice at a therapeutic setting with virus titer of the lung reduced by 4.5 logs. Structural analysis by cryo-EM revealed that CA521FALA recognizes an epitope overlapping with angiotensin converting enzyme 2 (ACE2)-binding sites in SARS-CoV-2 RBD in the Spike protein. CA521FALA blocks the interaction by binding all three RBDs of one SARS-CoV-2 spike trimer simultaneously. These results demonstrate the importance for antibody-based therapeutic interventions against COVID-19 and identifies CA521FALA a promising antibody that reacts with SARS-CoV-2 Spike protein to strongly neutralize its activity.

Epidemiological features of traumatic spinal cord injury in Guangdong Province, China.

Study design: A retrospective hospital-based study.Objective: To describe the epidemiological profile of traumatic spinal cord injury (TSCI) in Guangdong Province.Setting: Two hospitals within Guangdong Province, China.Methods: Medical records of patients diagnosed with TSCI admitted to Foshan Hospital of Traditional Chinese Medicine and Zhujiang Hospital of South Medical University from 1 January 2011 to 31 December 2015 were retrospectively reviewed. Epidemiological characteristics, such as age, sex, occupation, etiology, neurological level of injury, American Spinal Injury Association Impairment Scale at admission, death and cause of death during the acute hospitalization and concomitant injuries.Results: During the study period, 482 cases were identified. Male-to-female ratio was 3.4:1, with a mean age of 41.5 ± 12.6 years old. The leading cause was falls (49.3%), followed by motor vehicle collisions (MVCs) (34.8%). The most common injury site was the cervical spinal cord, especially C4-C6, accounting for 39.8%.Conclusion: The number of TSCI patients in Guangdong Province is large and is exhibiting a rising trend. The leading causes were falls and MVCs. The low-falls (height < 1 m) group has expanded over this period. With China entering an ageing society, more appropriate preventative measures should be implemented for fall-related injuries among the elderly.

Double-level isthmic spondylolisthesis treated with posterior lumbar interbody fusion with cage.

Objective: Double-level isthmic spondylolisthesis in the lumbar spine is rare. The authors report on 21 cases of double-level isthmic spondylolisthesis treated by posterior lumbar interbody fusion (PLIF) with cage.Patients and methods: Between 2005 and 2015, twenty-one patients with double-level isthmic spondylolisthesis who underwent posterior lumbar interbody fusion (PLIF) with cage were reviewed retrospectively. The VAS (Visual Analogue Scale) and JOA (Japanese Orthopedic Association) score were used to evaluate preoperative and postoperative clinical outcomes.Results: The back pain and sciatica decreased from 6.53 and 4.24 points preoperatively to 1.80 and 1.18 points on the VAS at final follow-up, respectively. The average JOA score improved from 13.4 ± 3.2 preoperative to 25.4 ± 1.5 (range, 17-28) points postoperative. The average recovery rate was 76.9%. The good and excellent rate was 85.7% (18/21). The fusion rate was 95.2% (20/21). Changes in disc height, degree of listhesis, whole lumbar lordosis, and sacral inclination following surgery were also observed.Conclusions: Our results suggest that PLIF with cage appears to be an appropriate technique for the treatment of double-level isthmic spondylolisthesis.

Environmental effect of decentralization on water quality near the border of cities: Evidence from China's Province-managing-county reform.

This study examines the environmental effects of decentralization on water quality in Chinese counties near the border of cities using data from local monitoring stations. Applying the generalized difference-in-difference-in-differences method, this analysis takes the province-managing-county reform as a quasi-natural experiment for decentralization and shows that four indexes of water quality in reformed counties near city borders are 10%-20% better than that of otherwise identical counties. This study suggests that the reform has a positive effect on environments near borders, which is attributed to the mitigation effect of increased public revenue, the mechanization effect of mechanized agriculture, and the home market effect of a narrowed market. By providing an intensive analysis of the three mechanisms, the paper implies that a well-designed decentralization reform can benefit the environment in addition to meeting its economic goals.

Arachnoiditis ossificans associated with syringomyelia: a case report.

The association of arachnoiditis ossificans with syringomyelia is a rare pathological entity. We present an unusual case who presented with progressive myelopathy caused by arachnoidits ossificans and syringomyelia. The pathophysiology and treatment strategy of this rare entity are still controversial.

Double-level isthmic spondylolisthesis treated with posterior lumbar interbody fusion: A review of 32 cases.

OBJECTIVE: The incidence of double-level isthmic spondylolisthesis is rare. The aim of this study is to evaluate the short-term functional and radiological outcomes of surgical treatment for double-level isthmic spondylolisthesis. PATIENTS AND METHODS: Between 2004 and 2014, thirty-two patients with double-level isthmic spondylolisthesis who underwent posterior lumbar interbody fusion (PLIF) with autogenous bone chips were reviewed retrospectively. The clinical outcomes were measured by VAS (Visual analog scale) and JOA(Japanese Orthopedic Association) score. RESULTS: At an average follow-up of 2.8 years, the mean score on the VAS of back pain and sciatica decreased from 6.48 and 4.26 points preoperatively to 1.82 and 1.10 points at final follow-up, respectively. The average JOA score improved from 13.8±3.1 preoperative to 25.6±1.3 (range, 17-28) points postoperative. The average recovery rate was 77.6%. The good and excellent rate was 84.3% (27/32). The fusion rate was 87.5% (28/32). Changes in disc height, degree of listhesis, whole lumbar lordosis, and sacral inclination between the pre- and postoperative periods were significant. CONCLUSIONS: Our findings suggest that PLIF with autogenous bone chips for double-level isthmic spondylolisthesis could yield good functional short-term results. It seems to be a viable approach in the treatment of double-level isthmic spondylolisthesis.

Spatial Analysis of China Province-level Perinatal Mortality.

BACKGROUND: Using spatial analysis tools to determine the spatial patterns of China province-level perinatal mortality and using spatial econometric model to examine the impacts of health care resources and different socio-economic factors on perinatal mortality. METHODS: The Global Moran's I index is used to examine whether the spatial autocorrelation exists in selected regions and Moran's I scatter plot to examine the spatial clustering among regions. Spatial econometric models are used to investigate the spatial relationships between perinatal mortality and contributing factors. RESULTS: The overall Moran's I index indicates that perinatal mortality displays positive spatial autocorrelation. Moran's I scatter plot analysis implies that there is a significant clustering of mortality in both high-rate regions and low-rate regions. The spatial econometric models analyses confirm the existence of a direct link between perinatal mortality and health care resources, socio-economic factors. CONCLUSIONS: Since a positive spatial autocorrelation has been detected in China province-level perinatal mortality, the upgrading of regional economic development and medical service level will affect the mortality not only in region itself but also its adjacent regions.

Comparison of posterior lumbar interbody fusion (PLIF) with autogenous bone chips and PLIF with cage for treatment of double-level isthmic spondylolisthesis.

INTRODUCTION: Spondylolytic defects involving multiple vertebral levels are rare. It is reported that only 1.48% of patients with back pain were diagnosed with multi-level spondylolysis. The incidence of multiple-level spondylolisthesis is even rarer, so far there have been few reports of multi-level isthmic spondylolisthesis in the literature. The aim of this study is to evaluate clinical and radiological outcomes of two different fusion techniques for treatment of double-level isthmic spondylolisthesis. METHODS: Fifty-four patients who were managed surgically for treatment of double-level symptomatic isthmic spondylolisthesis were included in this study. Between May 2004 and September 2012, 29 consecutive patients underwent posterior lumbar interbody fusion (PLIF) with autogenous bone chips (group I) at Foshan Hospital of Traditional Chinese Medicine, Guangdong, China. Between March 2005 and December 2013, 25 consecutive patients underwent PLIF with cage (group II) at Zhujiang Hospital of Southern Medical University, Guangdong, China. The mean follow-up periods were 27.2 and 26.8 months, respectively. RESULTS: The mean VAS scores of back and leg pain significantly decreased from 7.2 to 2.2 and 5.8 to 2.1 in the group I and from 7.0 to 1.9 and 6.1 to 1.8 in the group II, respectively. In the group I, mean ODI scores improved significantly from 54% to 14.2% and, in the group II, from 60% to 12.6%. In both groups, VAS and ODI scores significantly changed from pre- to postoperatively (p<0.001), but postoperative outcome between groups was statistically not significant. Solid union was observed in 27 of 29 patients (89.6%) in the group I and in 22 of 25 patients (88%) in the group II, without statistically significant differences (p>0.05). In both groups, changes in disc height, degree of listhesis, and whole lumbar lordosis between the pre- and postoperative periods were significant. CONCLUSION: Clinical and functional outcomes demonstrate no significant differences between groups in treating back and leg pain of adult patients with double-level isthmic spondylolisthesis.

Metagenomic analysis of microbiome in colon tissue from subjects with inflammatory bowel diseases reveals interplay of viruses and bacteria.

Inflammatory bowel diseases (IBD), Crohn's disease and ulcerative colitis, are poorly understood disorders affecting the intestinal tract. The current model for disease suggests that genetically susceptible patients develop intolerance to gut microflora, and chronic inflammation develops as a result of environmental insults. Although interest has mainly focused on studying genetic variants and gut bacterial flora, little is known about the potential of viral infection to contribute to disease. Accordingly, we conducted a metagenomic analysis to document the baseline virome in colonic biopsy samples from patients with IBD in order to assess the contribution of viral infection to IBD. Libraries were generated from colon RNA to create approximately 2 GB sequence data per library. Using a bioinformatic pipeline designed to detect viral sequences, more than 1000 viral reads were derived directly from tissue without any coculture or isolation procedure. Herein, we describe the complexity and abundance of viruses, bacteria/bacteriophage, and human endogenous retroviral sequences from 10 patients with IBD and 5 healthy subjects undergoing surveillance colonoscopy. Differences in gut microflora and the abundance of mammalian viruses and human endogenous retroviruses were readily detected in the metagenomic analyses. Specifically, patients with herpesviridae sequences in their colon demonstrated increased expression of human endogenous viral sequences and differences in the diversity of their microbiome. This study provides a promising metagenomic approach to describe the colonic microbiome that can be used to better understand virus-host and phage-bacteria interactions in IBD.

Lumbar intraosseous schwannoma: case report and review of the literature.

Intraosseous schwannomas of the mobile spine are extremely rare. To our knowledge, only 21 cases have been reported in the literature. In this report, we present a case of schwannoma involving the lumbar spine, with a review of the literature and discussion of this rare tumor. A 44 year old male presented with a 3 year history of intermittent low back pain, with radiation into the right lower extremity during the last 2 years. Radiographs revealed an approximately 4 x 4 cm irregular mass with marginal sclerosis located at the L5 vertebra, involving the right pedicle and extruding into the spinal canal. The tumor was resected completely and was confirmed as schwannoma by histological examination. At follow up after 12 months, the patient was free of pain and with no recurrence. Despite its low incidence, intraosseous schwannomas should be considered as the differential diagnosis of an extradural mass involving the vertebrae. Surgery is the preferred treatment method and usually carries a good prognosis.

Purification, cloning, characterization, and N-glycosylation analysis of a novel ß-fructosidase from Aspergillus oryzae FS4 synthesizing levan- and neolevan-type fructooligosaccharides.

ß-Fructosidases are a widespread group of enzymes that catalyze the hydrolysis of terminal fructosyl units from various substrates. These enzymes also exhibit transglycosylation activity when they function with high concentrations of sucrose, which is used to synthesize fructooligosaccharides (FOS) in the food industry. A ß-fructosidase (BfrA) with high transglycosylation activity was purified from Aspergillus oryzae FS4 as a monomeric glycoprotein. Compared with the most extensively studied Aspergillus spp. fructosidases that synthesize inulin-type ß-(2-1)-linked FOS, BfrA has unique transfructosylating property of synthesizing levan- and neolevan-type ß-(2-6)-linked FOS. The coding sequence (bfrAFS4, 1.86 kb) of BfrA was amplified and expressed in Escherichia coli and Pichia pastoris. Both native and recombinant proteins showed transfructosylation and hydrolyzation activities with broad substrate specificity. These proteins could hydrolyze the following linkages: Glc α-1, 2-ß Fru; Glc α-1, 3-α Fru; and Glc α-1, 5-ß Fru. Compared with the unglycosylated E. coli-expressed BfrA (E.BfrA), the N-glycosylated native (N.BfrA) and the P. pastoris-expressed BfrA (P.BfrA) were highly stable at a wide pH range (pH 4 to 11), and significantly more thermostable at temperatures up to 50°C with a maximum activity at 55°C. Using sucrose as substrate, the Km and kcat values for total activity were 37.19±5.28 mM and 1.0016±0.039×104 s-1 for N.BfrA. Moreover, 10 of 13 putative N-glycosylation sites were glycosylated on N.BfrA, and N-glycosylation was essential for enzyme thermal stability and optima activity. Thus, BfrA has demonstrated as a well-characterized A. oryzae fructosidase with unique transfructosylating capability of synthesizing levan- and neolevan-type FOS.

Surgical treatment of double-level isthmic spondylolisthesis.

Isthmic spondylolisthesis, which is demonstrated in 4%-6% of the general population, is one of the most common types of spondylolisthesis. However, double-level isthmic spondylolisthesis is extremely rare. Only a few reports have examined the outcomes of surgical treatment of double-level spondylolisthesis. The authors present an unusual case of double-level isthmic spondylolisthesis of the lumbar spine. The patient had low-back pain for 20 years and did not respond to conservative treatment. Radiographs revealed bilateral pars defects at L-4 and L-5. Grade 2 isthmic spondylolisthesis was present, both at L4-5 and at L5-S1. The patient underwent decompression, reduction, and posterior lumbar interbody fusion with autogenous bone chips from posterior decompression. At follow-up after 12 months, the patient was free of pain, slippage was corrected, and fusion was achieved. Posterior lumbar interbody fusion with posterior instrumentation and reduction may yield good functional short-term results for double-level spondylolisthesis.

Identification of hepatotropic viruses from plasma using deep sequencing: a next generation diagnostic tool.

We conducted an unbiased metagenomics survey using plasma from patients with chronic hepatitis B, chronic hepatitis C, autoimmune hepatitis (AIH), non-alcoholic steatohepatitis (NASH), and patients without liver disease (control). RNA and DNA libraries were sequenced from plasma filtrates enriched in viral particles to catalog virus populations. Hepatitis viruses were readily detected at high coverage in patients with chronic viral hepatitis B and C, but only a limited number of sequences resembling other viruses were found. The exception was a library from a patient diagnosed with hepatitis C virus (HCV) infection that contained multiple sequences matching GB virus C (GBV-C). Abundant GBV-C reads were also found in plasma from patients with AIH, whereas Torque teno virus (TTV) was found at high frequency in samples from patients with AIH and NASH. After taxonomic classification of sequences by BLASTn, a substantial fraction in each library, ranging from 35% to 76%, remained unclassified. These unknown sequences were assembled into scaffolds along with virus, phage and endogenous retrovirus sequences and then analyzed by BLASTx against the non-redundant protein database. Nearly the full genome of a heretofore-unknown circovirus was assembled and many scaffolds that encoded proteins with similarity to plant, insect and mammalian viruses. The presence of this novel circovirus was confirmed by PCR. BLASTx also identified many polypeptides resembling nucleo-cytoplasmic large DNA viruses (NCLDV) proteins. We re-evaluated these alignments with a profile hidden Markov method, HHblits, and observed inconsistencies in the target proteins reported by the different algorithms. This suggests that sequence alignments are insufficient to identify NCLDV proteins, especially when these alignments are only to small portions of the target protein. Nevertheless, we have now established a reliable protocol for the identification of viruses in plasma that can also be adapted to other patient samples such as urine, bile, saliva and other body fluids.

Purification of fructooligosaccharides by immobilized yeast cells and identification of ethyl ß-D-fructofuranoside as a novel glycoside formed during the process.

A yeast strain (XS1) capable of selective utilization of fructooligosaccharides (FOSs) syrup was identified as Wickerhamomyces anomala. Cells of W. anomala XS1 were immobilized in calcium alginate and incubated with an FOS mixture at 30 °C. The purity of the FOS increased from 54.4% to 80.1% (w/w) as 93.6% of monosaccharides were metabolized while the oligosaccharides were not affected. The immobilized yeast cells could be recycled 10 times and the corresponding batch treatments achieved FOS purities around 80%. Thus, the method could be promising for large-scale purification of FOS syrup at low cost. A byproduct formed by the yeast was identified as ethyl ß-D-fructofuranoside by MS and NMR spectroscopy.