Two antibodies show broad, synergistic neutralization against SARS-CoV-2 variants by inducing conformational change within the RBD.

Continual evolution of the severe acute respiratory syndrome coronavirus (SARS-CoV-2) virus has allowed for its gradual evasion of neutralizing antibodies (nAbs) produced in response to natural infection or vaccination. The rapid nature of these changes has incited a need for the development of superior broad nAbs (bnAbs) and/or the rational design of an antibody cocktail that can protect against the mutated virus strain. Here, we report two angiotensin-converting enzyme 2 competing nAbs-8H12 and 3E2-with synergistic neutralization but evaded by some Omicron subvariants. Cryo-electron microscopy reveals the two nAbs synergistic neutralizing virus through a rigorous pairing permitted by rearrangement of the 472-489 loop in the receptor-binding domain to avoid steric clashing. Bispecific antibodies based on these two nAbs tremendously extend the neutralizing breadth and restore neutralization against recent variants including currently dominant XBB.1.5. Together, these findings expand our understanding of the potential strategies for the neutralization of SARS-CoV-2 variants toward the design of broad-acting antibody therapeutics and vaccines.

Endodomain truncation of the HIV-1 envelope protein improves the packaging efficiency of pseudoviruses.

HIV-1 remains one of the most devastating infectious pathogens without available vaccines. A valid neutralization assay using multiple representative virus strains is prerequisite for antibody response analysis in HIV-1 vaccine development, where HIV pseudoviruses (PsVs) commonly serve as surrogate agents for the authentic HIV, offering a safer manipulation in Biosafety Level 2+. However, PsV production is of low efficiency and is unstable in this field. Here, we optimize PsV production conditions via the use of alternative host cells, packaging ratios and gene truncation. We show that a 153-aa truncation of the endodomain substantially enhances the packaging efficiency of HIV PsVs, providing 4 to 25 times higher infection titers than the full-length Env. Further, we obtained a robust HIV-1 PsV panel covering 12 representative global strains for neutralization assay testing. This work sheds light on how to optimize HIV PsV packaging, and provides functional insight into the cytoplasmic domain of HIV-1.

Congenital blindness enhances perception of musical rhythm more than melody in Mandarin speakers.

This study adopted the Musical Ear Test [Wallentin, Nielsen, Friis-Olivarius, Vuust, and Vuust (2010). Learn. Indiv. Diff. 20, 188-196] to compare musical competence of sighted and congenitally blind Mandarin speakers. On the rhythm subtest, the blind participants outperformed the sighted. On the melody subtest, however, the two groups performed equally well. Compared with sighted speakers of non-tonal languages reported in previous studies [Wallentin, Nielsen, Friis-Olivarius, Vuust, and Vuust (2010). Learn. Indiv. Diff. 20, 188-196; Bhatara, Yeung, and Nazzi (2015). J. Exp. Psychol. Hum. Percept. Perform. 41(2), 277-282], sighted Mandarin speakers performed better only on the melody subtest. These results indicate that tonal language experience and congenital blindness exert differential influences on musical aptitudes with rhythm perception reflecting a cross-modal compensation effect and melody perception dominated by a cross-domain language-to-music transfer effect.

[Role of M-type phospholipase A2 receptor and its antibody in hepatitis B virus-associated membranous nephropathy].

OBJECTIVE: To examine levels of M-type phospholipase A2 receptor (PLA2R) and its antibody in the patients with hepatitis B virus-associated membranous nephropathy (HBV-MN), and to explore the correlation of PLA2R with laboratory parameters and pathological characteristics.
 Methods: A total of 49 adult patients with biopsy-proved HBV-MN were enrolled in this study. Levels of anti-PLA2R antibody in serum and PLA2R in renal tissue were detected. Patients were assigned into two groups: a positive PLA2R group and a negative PLA2R group. Differences in laboratory parameters and pathological characteristics were compared between the two groups.
 Results: Of 49 patients with HBV-MN, 17 had positive PLA2R expression in renal tissues. In the positive PLA2R group, 10 patients were positive for serum anti-PLA2R antibody. Patients with positive PLA2R expression in renal tissues showed higher levels of 24 hour urinary protein [(4.6±3.9) g/d], serum HbsAg (70.5%) and renal HbsAg expression (71%), while lower level of serum albumin [(24.1±7.5) g/L] than those of the negative group.
 Conclusion: PLA2R is expressed in the renal tissues and serum anti-PLA2R antibody can be detected in some HBV-MN patients. Positive PLA2R expression in renal tissue might be related to HbsAg deposition in serum and renal tissues. Patients with positive PLA2R expression in renal tissue have more severe glomerular sclerosis.

[Effect of pioglitazone on arteria carotis remodeling in patients with metabolic syndrome].

OBJECTIVE: To observe the effect of pioglitazone on carotid artery intima-media thickness (IMT) and plaque-positive rate in patients with metabolic syndrome, and to find a new way to improve arterial remodeling in patients with metabolic syndrome. METHODS: Patients with metabolic syndrome were randomly divided into a control group (n=60) and a pioglitazone group (n=61). All subjects received basic therapeutic measures, i.e, appropriate medication to control blood pressure, blood sugar and cholesterol. Pioglitazone (15 mg/d) was given to patients in the pioglitazone group, and placebo (vitamin C) in the control group for 24 weeks. Color doppler ultrasound was used to measure carotid artery IMT and plaque-positive rate of patients in the 2 groups after the intervention. Japan's Hitachi 7600-020 automatic biochemical analyzer was used to measure fasting serumal triglycerides, total cholesterol, high density lipoprotein cholesterol, low-density lipoprotein cholesterol, free fatty acids, fasting blood glucose, 2-hour postprandial glucose and liver and kidney function, etc. The differences between groups after the intervention were analyzed and compared in IMT, plaque-positive rate and all blood biochemical indicators. RESULTS: After the intervention, compared with the control group, carotid artery plaque-positive rate and the levels of triglyceride and free fatty acid decreased in the pioglitazone group (P<0.05), but there was no difference in IMT of carotid artery and other blood biochemical indicators between the 2 groups (P>0.05). CONCLUSION: Pioglitazone intervention can significantly improve pathologic artery remodeling, and it can more effectively inhibit the arterial plaque-formation than basic therapeutic measures in patients with metabolic syndrome.

Evaluation of renal clinicopathological changes in IgA nephropathy by urinary podocytes excretion and podocalyxin expression.

OBJECTIVE: To explore the association of urinary podocyte excretion and renal expression of podocyte-specific marker podocalyxin (PCX) with clinicopathological changes in immunoglobulin A nephropathy (IgAN). METHODS: Morning urine samples from IgAN patients and healthy controls were collected. The expression of glomerular PCX was quantified in 50 IgAN patients diagnosed by renal biopsy. IgAN was classified based on the Lee's Grading system and scored according to the Katafuchi semiquantitative criteria. Morphological evaluation of podocyte was determined by electron microscopy. RESULTS: The amount of urinary podocytes in the IgAN patients was significantly higher than that in the healthy controls (p < 0.01). Pairwise comparison among Lee's grades of IgAN showed that the median of urinary podocytes in Lee's I-II group was lower than that in Lee's III, IV, and V groups (p < 0.05); group III lower than group V (p < 0.05). The positive rate of urinary podocytes was the highest in Lee's IV and V groups (100%), and lowest in Lee's I-II group (55%). Multiple comparison among groups of Lee's grades of IgAN showed that the glomerular PCX expression in Lee's I-II group was higher than that in Lee's III, IV, and V groups (p < 0.05); groups III and IV higher than group V (p < 0.05). The amount of urinary podocytes in IgAN patients was negatively correlated with PCX expression (r = -0.702, p < 0.01), but positively correlated with 24-h urinary protein (r = 0.465, p < 0.01) and glomerular (r = 0.233, p < 0.01) and renal tubular pathological scores (r = 0.307, p < 0.05). The glomerular PCX expression was negatively correlated with 24-h urinary protein (r = -0.367, p < 0.05) and glomerular (r = -0.560, p < 0.05) and tubular pathological scores (r = -0.377, p < 0.05). Electron microscopy showed significant changes in podocytes of IgAN, especially in the foot process. CONCLUSION: The amount of urinary podocyte can reflect the loss of podocytes in renal tissue, which may be a marker of IgAN progression.

Mast cell infiltration is involved in renal interstitial fibrosis in a rat model of protein-overload nephropathy.

AIMS: The present study investigated the relationship between mast cells (MCs) and the protein expression of stem cell factor (SCF) and transforming growth factor-ß1 (TGF-ß1) in the regions of renal interstitial fibrosis with protein-overload nephropathy, in order to provide a good animal model to study the mechanism of renal fibrosis induced by proteinuria. METHODS: 60 male Sprague-Dawley rats were divided into a bovine serum albumin (BSA) group and a control group. The intensity of MCs infiltration was examined by toluidine blue and chymase and tryptase staining. The protein expression of SCF and TGF-ß1 was respectively examined by immunohistochemical and immunofluorescence staining. RESULTS: Severe proteinuria was induced in rats of the BSA group. Expression of SCF and TGF-ß1 was detected in the tubular and the interstitial cells. The number of MCs positively correlated with the severity of interstitial lesions and the expression of SCF and TGF-ß1. CONCLUSION: Our results demonstrated that in protein-overload nephropathy, MCs infiltrated into the kidney, and the expression of SCF and TGF-ß1 gradually increased. They might play important roles in the development of renal interstitial fibrosis, but the underlying mechanism needs to be further studied.

Molecular characterization of a Chinese pedigree with beta-thalassemia intermedia.

Hereditary persistence of fetal hemoglobin (HPFH), often associated with mutations in the beta-globin gene cluster, is normally benign, but a person carrying both HPFH and another beta-thalassemia (beta-thal) mutation will develop serious anemia. These people might be erroneously diagnosed as having homozygous beta-thal with common reverse dot-blot methods. Here we report a 5-year old boy with thalassemia intermedia, who is a compound heterozygote for the rare HPFH-6 deletion with codons 41/42 (-TCTT) beta(0)-thal, who inherited the deletion from his mother and the beta(41/42) mutation from his father.

[Establishment of a rat model of mycoplasma pneumonia and the treatment].

OBJECTIVE: To establish a rat model of mycoplasma pneumonia (MP) for investigating the pathogenesis of MP and its therapy with drugs. METHODS: Thirty Wistar rats were randomly divided into 6 groups (n=5), including a control group, a MP model group, a erythromycin lactobionate group and 3 erythromycin microspheres groups (high, middle, and low dose groups). With the exception of those in the control group, all the rats received intranasal MP administration followed by corresponding treatments administered via tail vein injection. At different time points after inoculation of the pathogen, the lungs of the rats were taken for histopathological scoring. RESULTS: In the MP model group, the lung pathology was characterized by patchy interstitial pneumonitis with predominantly lymphocyte infiltration and mucosal edema. The bronchiolar walls became thickened and the lumens narrowed. In erythromycin lactobionate and erythromycin microspheres treatment (high and middle dose) groups, clear cell boundaries were observed in the lungs where no obvious pathological changes were found. RT-PCR amplification showed positive results of MP RNA in the model group, erythromycin lactobionate group and erythromycin microsphere groups. CONCLUSION: The approach described is practicable to establish rat models of MP. Erythromycin microspheres can effectively relieve the lung inflammations and has therapeutic effect on MP.

[Chronic toxicity of 97% isopropyl thioxanthone in rat by oral administration for 2 years].

OBJECTIVE: To study the oral chronic toxicity of 97% isopropyl thioxanthone (97% ITX) in rats, determine the no-observed adverse effect levels (NOAEL). METHODS: Four groups of rats were fed with foodstuff containing 97% ITX in the dosage of 1000.0, 250.0, 62.5 mg/kg respectively for 2 years. The general behavior, body weight, food availability ect. were observed during the experiment. At the end of the experiment, blood and urine samples were collected for routine and biochemical assays. The internal organs were taken for calculating their organ coefficients and histopathological examinations. RESULTS: During the experimental period, no obvious abnormality were found in the experimental animals. The body weight and the total food availability rate in the high dosage group of male were lower than that of control (P < 0.05). Hematology examination showed that the quantity of Hb and RBC in high dosage groups of both the male and female and Hb in the male middle group were all lower than the control group (P < 0.01 or P < 0.05). Analysis of correlation indicated that r = -0.433, P < 0.01 in male, r = -0.337, P < 0.01 in female of Hb; r = -0.266, P < 0.05 in male, r = -0.317, P < 0.01 in female of RBC. There were obviously negative correlation. Serum biochemistry examination showed the concentration of CHO in the high and middle dosage treated rats of male and female were higher than that of the control (P < 0.01 or P < 0.05). Analysis of correlation indicated that r = 0.497, P < 0.01 in male, r = 0.417, P < 0.01 in female. No abnormality were found in urine examination. The organ weight and organ coefficient such as liver, were higher than control group (P < 0.01). The result of histopathological examinations displayed that the renal tubule Cast and the tubulointerstitial nephritis in the treated groups were higher than that of control group (P < 0.01). CONCLUSION: 97% ITX could obviously interfere with the animals' physical condition, and reduce the number of RBC and the concentration of Hb in the blood, interact metabolism of lipoid and induce the concentration of CHO in the serum. The livers of the treated rats are compensatory enlarged. And kidneys of the poisoning animals are damaged. The 2 years oral NOAEL of 97% ITX in rats are more than 4.63 mg/kg for female rats, and larger than 4.06 mg/kg for male rats.

[Antimicrobial effects of erythromycin microspheres against Mycoplasma Pneumoniae in rats].

OBJECTIVE: To evaluate the antimicrobial effects of erythromycin microspheres against Mycoplasma pneumoniae in rats. METHODS: With erythromycin lactobionate as the positive control, erythromycin microspheres at 3 non-toxic doses (0.1, 0.5, and 1.2 g.kg(-1).d(-1)) were administered intragastrically for 6 consecutive days in Wistar rats with Mycoplasma pneumoniae infection. The general condition and lung index of the rats were observed and measured to assess the therapeutic effects of the treatments against Mycoplasma pneumoniae infection. RESULTS: The erythromycin microspheres at 0.1, 0.5, 1.2 g.kg(-1).d(-1) significantly alleviated the symptoms of the rats infected with Mycoplasma pneumoniae and reduced the pulmonary index of the infected rats from 1.75 to 1.45, 1.38 and 1.25, respectively (P < 0.01). An obvious dosage-effect relationship was noted between the dose of erythromycin microsphere and the tissue pathologies due to the infection. CONCLUSION: Erythromycin microspheres possess strong activity against Mycoplasma pneumoniae in rats.

Antiviral activity of nano carbon fullerene lipidosome against influenza virus in vitro.

The activity of nano carbon fullerene lipidosome (NCFL) against influenza virus H1N1 in vitro was studied by observing the cytotoxicities and its activity rendered by different intensities of lighting with various periods of time. Rimantadine hydrochloride was used as the positive control drug. By using microcultural technique, the morphological changes of cells were observed and by using the gentian violet staining, antiviral activity of the NCFL against influenza virus was assayed. The results showed that: (1) The maximal concentration of the NCFL was 7 microg/mL and the 50% toxic concentration (TC(50)) was 13.54 microg/mL respectively; (2) NCFL had a significant activity of directly killing the influenza virus, while the activities in antiadsorption and antireplication were not obvious; (3) There was a dose-activity relationship between the dosages of NCFL and the direct killing effect against the influenza virus, and the periods of lighting-time could influence the activity partly. It was concluded that NCFL had a significant activity of directly killing the influenza virus.

[Rapid detection of oxacillin and erythromycin resistance genes in Staphylococcus aureus using multiplex PCR].

OBJECTIVE: To establish a rapid multiplex PCR (MPCR) detection system of oxacillin and erythromycin resistance genes in Staphylococcus aureus (S. aureus) and evaluate the genotype distribution of the genes associated to mecA, ermA and ermC resistance in Guangzhou. METHODS: The S. aureus strains were identified and susceptibility tests were performed using VITEK-60 or PHOENIX-100 system. The inducible resistance to clindamycin of strains with of erythromycin resistance was conducted using D-test, and the MPCR system of for detecting the antibiotic resistance genes was optimized. RESULTS: The MPCR assay for detecting the resistance genes was constructed successfully. According to the results of MPCR, the positivity rates for mecA, ermA and ermC genes among the 124 strains of S. aureus isolated from clinical samples were 56.5%, 50% and 33.9%, respectively. Good correlation was observed between the antibiotic resistance phenotypes and the S. aureus genotypes. mecA were detected in all the methicillin-resistant S. aureus strains, and ermA and/or ermC in 97.7% of the S. aureus strains with erythromycin resistance. CONCLUSION: This MPCR system allows rapid and reliable analysis of antibiotic resistance genotypes of S. aureus isolated from clinical samples. mecA, ermA, and ermC genes are among the predominant genetic determinants for the resistance to oxacillin and erythromycin in S. aureus isolates in Guangzhou.

Antiviral Activity of Nano Carbon Fullerene Lipidosome against Influenza Virus/In Vitro / 华中科技大学学报（医学）（英德文版）

The activity of nano carbon fullerene lipidosome (NCFL) against influenza virus HINI in vitro was studied by observing the cytotoxicities and its activity rendered by different intensities of lighting with various periods of time. Rimantadine hydrochloride was used as the positive control drug. By using microcultural technique, the morphological changes of cells were observed and by using the gentian violet staining, antiviral activity of the NCFL against influenza virus was assayed. The results showed that: (1) The maximal concentration of the NCFL was 7μg/mL and the 50% toxic concentration (TC50) was 13.54μg/mL respectively; (2) NCFL had a significant activity of directly killing the influenza virus, while the activities in antiadsorption and antireplication were not obvious; (3) There was a dose-activity relationship between the dosages of NCFL and the direct killing effect against the influenza virus, and the periods of lighting-time could influence the activity partly. It was concluded that NCFL had a significant activity of directly killing the influenza virus.

[Nephrotoxicity of high- and low-osmolar contrast media: Protective role of fosinopril or telmisartan in a rat model].

OBJECTIVE: To compare the nephrotoxicity of high- and low-osmolar contrast media (HOCM and LOCM), and to determine the protective role of fosinopril or telmisartan and its possible mechanism. METHODS: Forty eight healthy SD rats were randomly divided into 6 groups: a normal control group, a glycerol control group, a low-osmolar contrast media (LOCM) group, a high-osmolar contrast media (HOCM) group, a fosinopril group, and a telmisartan group. Glycerine for inducing kidney damage was given to all rats except the normal control group. Twenty-four hours after the injection of glycerine, the mixed fosinopril suspension (10mg/kg) or telmisartan (5mg/kg) was poured into the stomach in the preventive group. Serum creatinine (SCr) and plasma angiotensin II (AngII) levels were detected by an automatical biochemical analyzer and radioimmunoassay; caspase-3 activity and claudin-1 expression of the renal tissue were detected by fluorometric method and immunohistochemical method. The renal injury was assessed by hematoxylin and eosin (HE) staining and terminal deoxynucleotide mediated nick and labeling (TUNEL) staining, respectively. RESULTS: In diatrizoate-injected rats, SCr and AngII levels were increased (P<0.05). Expression of claudin-1 protein and caspase-3 activity in the renal tissue was upregulated. The histologic changes and percentage of apoptotic cells were milder in the LOCM rats than those in the HOCM rats. In the group pretreated with fosinopril or telmisartan, no increase in the levels of SCr and AngII was discovered. The expression of claudin-1 protein and caspase-3 activity was significantly lower than that in the HOCM group. The renal injuries induced by diatrizoate were alleviated. CONCLUSION: Both HOCM and LOCM could cause cellular apoptosis in the kidney.LOCM was less toxic to rat kidney than HOCM. Nephrotoxicity induced by HOCM might be related to caspase-3, claudin-1 and AngII. Fosinopril or telmisartan may protect the renal tissue from nephrotoxicity induced by diatrizoate.

[Identification and tissue localization of intermediate filament protein in Angiostrongylus cantonensis].

OBJECTIVE: To identify the type of the intermediate filament (IF) protein of Angiostrongylus cantonensis and analyze its tissue localization. METHODS: Recombinant pET-IF of antigen IF was expressed in E.coli with IPTG induction, and the expression products were purified by His.Bind column and identified for determining the type of the IF protein by Western blotting. Anti-IF antibody was prepared by multi-spot subcutaneous injection into mouse and used to detect the tissue slices of A. cantonensis by immunohistochemical analysis. RESULTS: The antigen IF were correctly expressed and purified, and identified as a keratin located in the intestine wall and cytoplusma. CONCLUSION: The antigen IF is distributed in the intestine wall of A. cantonensis.

[Induced differentiation and signaling factor PTEN expression of 3T3-L1 adipocytes].

OBJECTIVE: To optimize the condition for inducing the differentiation of 3T3-L1 preadipocytes into adipocytes and study the expression of PTEN tumor suppression gene in this process, aiming to understand the regulatory role of PTEN in normal adipocyte differentiation and collect laboratory evidence for developing drugs targeting PTEN. METHODS: The differentiation of 3T3-L1 preadipocytes cultured in high-glucose DMEM were induced according to 2 protocols with different combinations of dexamethasone, isobutylmethylxanthine (IBMX) and insulin, and the resultant adipocytes were identified by oil red O staining. The total proteins of 3T3-L1 were extracted and analyzed by Western blotting, and PTEN homology between mice and human was analyzed by bioinformatic method. RESULTS: For optimized 3T3-L1 differentiation, 3T3-L1 cells were initially induced with the combination of 1 micromol/L dexamethasone, 0.5 mmol/L IBMX and 5 microg/ml insulin for 48 h, followed by treatment with 5 microg/ml insulin in 4.5 g/L glucose DMEM for 48 h, which resulted in high differentiation rate of 3T3-L1 cells (up to 90% on the 10th day) with unified morphology and size. PTEN expression varied quantitatively in the process of differentiation, especially low on the 12th day as compared with those measured on days 4, 6 and 9. The mice PTEN mRNA shared 96% homology and PTEN amino acid 100% homology with their human counterparts. CONCLUSION: Endogenous PTEN expression is down-regulated during 3T3-L1 differentiation, suggesting that PTEN may enhance insulin sensitivity and promote adipogenesis under physiological conditions.

[Effects of Alternanthera philoxeroides Griseb against respiratory syncytial virus infection in mice].

OBJECTIVE: To investigate the effect of an oral preparation of Alternathera philoxeroides Griseb (APG) against respiratory syncytical virus (RSV) in mice. METHODS: APG preparation was administered orally in RSV-infected mice at different daily doses (2.5, 4.5 and 6.5 g/kg) to observe the therapeutic effect of the preparation. RESULTS: Distinct differences were observed between the death rate of the mice treated with APG at daily dose of 4.5 and 6.5 g/kg and that of the untreated mice with infection. After AGP treatment of the mice at 6.5 g/kg, the detection rate of the virus was 31.3% in the blood and 37.5% in the lung tissue, significantly lower than that in the untreated mice. The virus detection rate was 43.8% in the lung tissues of mice treated with APG at 4.5 g/kg, also significantly lower than that in the untreated control. APG treatment at the 3 doses resulted in different lung indices from that of the control. CONCLUSION: APG may be effective for treatment of RSV infection.

[Investigation of viral pathogens contributing to habitual abortion].

OBJECTIVE: To investigate the association of Coxsackie B virus (CBV) with habitual abortion. METHODS: CBV IgM antibody, viral RNA and virions were detected in 86 women with habitual abortion and 40 with induced abortion by means of enzyme-linked immunosorbent assay (ELISA), RT-PCR and virus isolation, respectively. RESULTS: The positivity rate of CBV IgM were 87.2% and 35% in the two groups, respectively, and the detection rate of the viral RNA was 53.5% and 17.5% in blood lymphocytes, and 59.3% and 17.5% in the placentas. The virions were found in the placentas in 41.9% and 6.9% of the women, respectively. The positivity rates of CBV IgM, viral DNA and virions showed significant difference between the two groups (P<0. 01). CONCLUSION: CBV might be one of the causes responsible for habitual abortion.