Avaliação Cintilográfica e Ecocardiográfica em Portadores de Variantes Patogênicas ou Provavelmente Patogênicas do Gene TTR sem Envolvimento Cardíaco Manifesto / Scintigraphic and Echocardiographic Study of Patients with Pathogenic or Probably Pathogenic Variants of the TTR Gene without Overt Cardiac Involvement

Resumo Fundamento: A amiloidose por transtirretina (ATTR) é uma doença infiltrativa causada pela deposição anormal de proteína principalmente no coração e no sistema nervoso periférico. Quando acomete o coração, a doença manifesta-se como uma cardiomiopatia restritiva e, quando afeta o sistema nervoso periférico e autônomo, apresenta-se como uma polineuropatia, podendo ser chamada de Polineuropatia Amiloidótica Familiar (PAF). Existem dois subtipos de ATTR, a ATTR selvagem, em que não há variantes genéticas, e a ATTR hereditária, caracterizada por uma variante no gene que codifica a proteína transtirretina (T/TR). Em ambos os subtipos, o envolvimento cardíaco é o principal marcador prognóstico. Objetivos: Avaliar a prevalência do envolvimento cardíaco subclínico em uma amostra de pacientes com variantes genéticas no gene TTR usando a cintilografia com pirofosfato e o ecocardiograma com strain; comparar os achados cintilográficos e as medidas de strain; avaliar a associação entre PAF e o envolvimento subclínico; e analisar se existe uma associação entre uma variante genética específica e o envolvimento cardíaco. Métodos: Estudo transversal com carreadores de variantes no gene TTR sem sintomas cardiovasculares e sem alterações nos parâmetros da eletrocardiografia ou do ecocardiograma convencional. Todos os pacientes foram submetidos à cintilografia com pirofosfato e à ecocardiografia com análise de strain. O envolvimento cardíaco subclínico, definido como um escore de Perugini ≥ 2, razão Coração (C)/ Hemitórax Contralateral (CL) ≥ 1,5 em uma hora, C/CL ≥ 1,3 na terceira hora, ou um strain longitudinal global (SGL) ≤ −17%. Realizadas análises descritiva e analítica, e aplicados o teste exato de Fisher e o teste de Mann-Whitney. Um valor de p<0,05 foi considerado significativo. Resultados: Os 23 pacientes avaliados apresentavam uma idade mediana de 51 (37-57) anos, 15 (65,2%) eram do sexo feminino, 12 (52,2%) eram pardos, nove (39,1%) apresentavam hipertensão arterial sistêmica, e nove (39,1%) tinham um diagnóstico prévio de PAF. Dos nove pacientes com PAF, oito (34,8%) usavam tafamidis. As variantes genéticas identificadas foram Val142IIe, Val50Met e IIe127Val. O valor mediano do SGL foi −19% (-16% - −20%). Dos 23 pacientes, nove (39,1%; 95% CI = 29-49%) preencheram os critérios de envolvimento cardíaco, seis (26%) somente pelo critério do SGL. Não houve associação entre PAF e um carreador assintomático avaliado por ecocardiograma com análise de strain e pela cintilografia com pirofostato (p=0,19). A prevalência de hipertensão arterial sistêmica, diabetes mellitus, dislipidemia, tabagismo e SGL reduzido não foi diferente entre os grupos. A velocidade da onda e' septal foi a única variável que apresentou diferença significativa entre os indivíduos com e sem SGL reduzido, com uma área sob a curva ROC de 0,80 (IC95% = 0,61-0,98, p = 0,027). A melhor acurácia diagnóstica foi alcançada com uma velocidade e' septal ≤ 8,5 cm/s. Não houve associação entre o tipo de variante genética e o envolvimento cardíaco pré-clínico, nem entre o uso de tafamidis e este mesmo envolvimento (37,5% versus 40,0%, p = 0,90). Conclusão: O envolvimento cardíaco subclínico foi frequente em uma amostra de carreadores da variante genética do gene TTR. Um valor do SGL reduzido foi o achado mais comum. Não houve associação entre a presença de polineuropatia amiloidótica e o envolvimento subclínico. O tipo de variante genética não foi associado com envolvimento cardíaco precoce. Nesta amostra, o uso de tafamidis (20mg/dia) não foi associado com uma menor prevalência de envolvimento cardíaco subclínico.

Abstract Background: Transthyretin amyloidosis (ATTR) is an infiltrative disease caused by abnormal protein deposition mainly in the heart and peripheral nervous system. When it affects the heart, the disease presents as restrictive cardiomyopathy; when it affects the peripheral and autonomic nervous system, it manifests as polyneuropathy, and is called familial amyloid polyneuropathy (FAP). There are two ATTR subtypes: wild-type ATTR, where there is no mutation, and mutant ATTR (ATTRm), which is characterized by a mutation in the gene encoding the transthyretin protein (TTR). In both subtypes, cardiac involvement is the major marker of poor prognosis. Objectives: To assess the prevalence of subclinical cardiac involvement in a sample of patients with TTR gene mutation by using pyrophosphate scintigraphy and strain echocardiography; to compare scintigraphy and strain findings; to evaluate the association between neurological manifestations (FAP) and subclinical cardiac involvement; and to analyze whether there is an association between any specific mutation and cardiac involvement. Methods: This is a cross-sectional study with carriers of the TTR gene mutation, without cardiovascular symptoms or changes in electrocardiographic or conventional echocardiographic parameters. All patients underwent pyrophosphate scintigraphy and strain echocardiography. Subclinical cardiac involvement was defined as a Perugini score ≥ 2, heart-to-contralateral lung (H/CL) ratio ≥ 1.5 at 1 h, H/CL ≥1.3 at 3 h, or global longitudinal strain (GLS) ≤ −17%. Descriptive and analytical analyses were performed and Fisher's exact test and Mann-Whitney test were applied. A value of p < 0.05 was considered significant. Results: The 23 patients evaluated had a median age of 51 years (IQR 37-57 years), 15 (65.2%) were female, 12 (52.2%) were Pardo, nine (39.1%) had systemic arterial hypertension, and nine (39.1%) had a previous diagnosis of FAP. Of the nine patients with FAP, 8 (34.8%) were on tafamidis. The associated mutations were Val142IIe, Val50Met, and IIe127Val. The median GLS in the sample was −19% (−16% to −20%). Of the 23 patients, nine (39.1%; 95% CI = 29-49%) met criteria for cardiac involvement, six (26%) by the GLS-based criteria only. There was no association between having FAP and being an asymptomatic carrier, as assessed by strain echocardiography and pyrophosphate scintigraphy (p = 0.19). The prevalence of systemic arterial hypertension, diabetes mellitus, dyslipidemia, smoking, and reduced GLS did not differ between groups. Septal e' wave velocity was the only variable that significantly differed between individuals with and without reduced GLS, with an area under the ROC curve of 0.80 (95% CI = 0.61-0.98, p = 0.027). The best diagnostic accuracy was achieved with a septal e' velocity ≤ 8.5 cm/s. There was no association between mutation type and preclinical cardiac involvement, nor between tafamidis use and lower degree of cardiac involvement (37.5% versus 40.0%, p = 0.90). Conclusion: Subclinical cardiac involvement was common in a sample of TTR mutation carriers without cardiac involvement. Reduced left ventricular GLS was the most frequent finding. There was no association between the presence of amyloid polyneuropathy and subclinical cardiac involvement. Type of mutation was not associated with early cardiac involvement. In this sample, the use of tafamidis 20 mg/day was not associated with a lower prevalence of subclinical cardiac involvement.

Preparation and immunizing dose analysis of inactivated hepatitis A vaccine using attenuated H2 strain / 预防医学

Objective@#To prepare an inactivated hepatitis A vaccine using a attenuated strain of hepatitis A virus (HAV) H2 and to analyze its immunizing dose, so as to provide the reference for development and production of inactivated hepatitis A vaccines.@*Methods@#Human embryonic lung diploid cells (KMB17) were infected with attenuated HAV H2 strain to proliferate the virus, then the cells containing viruses were harvested, extracted and purified. The obtained virus concentrate was prepared into vaccine bulk and test vaccines with 1 280 EU/mL antigen content. Vaccine testing was carried out according to the inactivated hepatitis A vaccine standards specified in the Part Ⅲ of the Pharmacopoeia of the People's Republic of China (2020 edition). A total of 110 mice were randomly divided into 11 groups, including 5 dose groups (80, 160, 320, 640 and 1 280 EU/dose) of the test vaccine and the reference vaccine, as well as the adjuvant control group. Mice were immunized twice by intraperitoneal injection, their serum HAV antibodies were detected, and the geometric mean titer (GMT) and positive conversion rate of antibodies were analyzed to evaluate the immunising dose of the vaccine.@*Results@#The antigen content and viral titer of the virus harvest solution were 5 120 EU/mL and 8.33 lgCCID50/mL, respectively. The removal rate of foreign protein reached 98.05% and the recovery rate of antigen was 66.25%. The test vaccine met the requirements of Part Ⅲ of the Pharmacopoeia of the People's Republic of China (2020 edition). The GMTs of HAV antibodies in the test vaccine and the reference vaccine dose groups after the second immunization were more than twice higher than those after the first immunization. Regardless of primary immunization or secondary immunization, the GMTs (log2) of HAV antibodies in the test vaccine groups with doses of 160 EU/dose and above were higher than those in the 80 EU/dose group (all P<0.05), while there was no statistically significant differences between the dose groups of 160 EU/dose and above (all P>0.05). The antibody positive conversion rate of 160 EU/dose and above of the test vaccine was 100.00% after the secondary immunization.@*Conclusions@#The inactivated hepatitis A vaccine of attenuated H2 strain tested in this study demonstrates strong immunogenicity in mice, suggesting its potential as a candidate vaccine. The preliminary analysis indicates an immunizing dose of 320 EU/dose for children and 640 EU/dose for adults.

The Research Status of Novel Coronavirus Antibodies and Small Molecule Inhibitors / 生物化学与生物物理进展

The World Health Organization has declared that the outbreak of coronavirus disease 2019(COVID-19) is a global pandemic. As mutations occurred in the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the global epidemic still needs further concern. Worryingly, the effectiveness and neutralizing activity of existing antibodies and vaccines against SARS-CoV-2 variants is declining. There is an urgent need to find an effective antiviral medication with broad-spectrum inhibitory effects on novel coronavirus mutant strains against the SARS-CoV-2 infection. Neutralizing antibodies play an important role in the prevention and treatment of COVID-19. The interaction of spike-receptor-binding domain (Spike-RBD) of SARS-CoV-2 and human angiotensin-converting enzyme 2 (ACE2) is the first and critical step of SARS-CoV-2 infection. Hence, the SARS-CoV-2 Spike-RBD is a hot target for neutralizing antibodies development. Evusheld, the combination of Tixagevimab and Cilgavimab monoclonal antibodies (mAbs) targeting Spike-RBD exhibits neutralizing activity against BA.2.12.1, BA.4 and BA.5, which could be used as pre-exposure prophylaxis against SARS-CoV-2 infection. The nucleocapsid (N) protein is a conservative and high-abundance structural protein of SARS-CoV-2. The nCoV396 monoclonal antibody, isolated from the blood of convalescent COVID-19 patients against the N protein of SARS-CoV-2. This mAb not only showed neutralizing activity but also inhibits hyperactivation of complement and lung injury induced by N protein. The mAb 3E8 targeting ACE2 showed broadly neutralizing activity against SARS-CoV-2 and D614G, B.1.1.7, B.1.351, B.1.617.1 and P.1 variants in vitro and in vivo, but did not impact the biological activity of ACE2. Compared with neutralizing antibodies, small molecule inhibitors have several advantages, such as broad-spectrum inhibitory effect, low cost, and simple administration methods. Several small-molecule inhibitors disrupt viral binding by targeting the ACE2 and N-terminal domain (NTD) of SARS-CoV-2 spike protein. Known drugs such as chloroquine and hydroxychloroquine could also block the infection of SARS-CoV-2 by interacting with residue Lys353 in the peptidase domain of ACE2. The transmembrane protease serine 2 (TMPRSS2) inhibitors Camostat mesylate and Proxalutamide inhibit infection by blocking TMPRSS2 mediates viral membrane fusion. The main protease inhibitor Paxlovid and RNA-dependent RNA polymerase inhibitor Azvudine have been approved for treatment of COVID-19 patients. This review summarizes the current research status of neutralizing antibodies and small molecule inhibitors and prospects for their application. We expect to provide more valuable information for further studies in this field.

Identification of peak 2 protein on right side of main peak of SEC-HPLC in lyophilized human rabies vaccine (Vero cells) stock solution(without human blood albumin) / 中国生物制品学杂志

@#Objective To identify the peak 2 protein on the right side of the main peak of size exclusion chromatograghy-high performance liquid chromatography(SEC-HPLC)in freeze-dried human rabies vaccine(Vero cell)stock solution(without human blood albumin),so as to determine the protein composition of the peak and ensure the vaccine quality.Methods The lyophilized human rabies vaccine(Vero cells)stock solution(without human blood albumin)was analyzed by SECHPLC,of which the peak 2 on the right side of the main peak was collected and concentrated by ultrafiltration,then reduced by dithiothreitol(DTT),alkylated by iodoacetamide (IAM) and hydrolyzed by Trypsin. The products were analyzed by nano LC-MS/MS.Results Four proteins were successfully identified in the right peak 2 of SEC-HPLC main peak in lyophilized human rabies vaccine(Vero cell)stock solution(without human blood albumin),and the number of matching peptides for a single protein ranged from 59 to 79. The number of single protein-matching characteristic peptides ranged from 6 to 12. The detection times of single protein-matching characteristic peptide segments ranged from 20 to 36 times. The sequence coverage of the identified proteins ranged from 37. 40% to 64. 31%. A total of 280 peptides participated in the statistics,and the mass spectrum deviation was less than 0. 15 Da.Conclusion The peak 2 on the right side of SEC-HPLC main peak of lyophilized human rabies vaccine(Vero cell)stock solution(without human blood albumin)is derived from rabies strain 4a GV,which is the vaccine particle dissociation.

Research progress on the stress-strain index of Corvis ST / 国际眼科杂志(Guoji Yanke Zazhi)

Corneal visualization Scheimpflug technology(Corvis ST)is currently the most commonly used clinical device for assessing in vivo corneal biomechanics. The new parameter stress-strain index(SSI)has been a hot topic of clinical research in recent years, which not only directly reflect corneal biomaterial stiffness, but also closely correlates with the progression of certain diseases. SSI was generated based on the predictions of corneal behavior using finite element(FE)numerical modeling to simulate the effects of intraocular pressure and Corvis ST jets. The SSI algorithm does not change with central corneal thickness(CCT), intraocular pressure, or biomechanically corrected intraocular pressure(BIOP), but it is clearly associated with altered collagen fibres in the corneosclera. The principles of SSI, the relationship between age and SSI, the relationship between axial length and SSI, the relationship between myopia and SSI, and the application of SSI are summarized and concluded.

Antiviral Efficacy and Mechanism of BD-77 Against Novel Coronavirus SARS-CoV-2 / 中国实验方剂学杂志

ObjectiveThe human angiotensin converting enzyme2 （hACE2） transgenic mouse model was used to clarify the antiviral efficacy of BD-77 against a novel coronavirus SARS-CoV-2 and explore the action mechanism of BD-77 against SARS-CoV-2. MethodSARS-CoV-2 Omicron and Delta variant strains-infected VeroE6 cell models were established and administered with BD-77 to observe the antiviral effect of BD-77 in vitro. A kit was used to detect the effect of BD-77 in vitro on the binding of spike S protein of SARS-CoV-2 virus （Delta/Omicron） to angiotensin converting enzyme2 （ACE2）. Chromatography was adopted to detect the binding of BD-77 to the S protein and N protein of the novel coronavirus. hACE2 transgenic C57BL/6 mice were divided into a blank control group， SARS-CoV-2 infection group， BD-77 administration groups of 37.5 mg·kg-1 and 75 mg·kg-1， with eight mice in each group. The pneumonia model of SARS-CoV-2-infected hACE2 transgenic mice was built to observe the survival of the mice， detect the virus titer of the lung tissue of the mice， and observe the lesions in the lung tissue. ResultBD-77 had a certain inhibitory effect on Omicron and Delta variant strains in vitro， with median inhibitory concentration （IC50） of 526.3 mg·L-1 and 653.0 mg·L-1， respectively. BD-77 had no significant inhibitory effect on the binding of the S protein of WT， Omicron， and Delta variant strains of SARS-CoV-2 to ACE2 and had no binding effect with the S protein and N protein of the novel coronavirus. No mice in the blank group died， while the mortality rate of SARS-CoV-2-infected mice was 75%. There was a large amount of virus replication in the lung tissue of the mice and large areas of inflammatory infiltration in the lung tissue and interstitium. Compared with the model group， BD-77 administration groups of 37.5 mg·kg-1 and 75 mg·kg-1 could reduce the mortality of mice， significantly lower the virus titer in the lung tissue of mice （P<0.05）， and improve lung lesions. ConclusionBD-77 demonstrated significant inhibitory effects against SARS-CoV-2 virus in vitro and in vivo. However， its mechanism of action did not involve direct inhibition of the virus itself or intervention in the virus-host binding process. This finding suggests that the mechanism of action of BD-77 needs to be thoroughly investigated and elucidated by further experiments.

Effect of production site change on quality of live attenuated varicella vaccine / 中国生物制品学杂志

@#Objective To evaluate the effect of production site change of vaccine production on the quality of live attenuated varicella vaccine at the molecular level.Methods Using next-generation sequencing(NGS),the varicella-zoster virus(VZV)Oka strain virus seed(VW-before,SYVW-after)and vaccine bulk(P-before,YZP-after)produced before and after prodution site change were subjected to DNA extraction,purification,library construction and sequencing,and the quality control of the sequencing results were performed.Taking gene sequence of Dumas strain registered in GenBank(NC＿001348)as the position reference genome,the whole gene sequences of the four samples before and after prodution site change were compared with the Oka strain virus to obtain the mutation sites,base changes and variant allele frequency(VAF),and the consistency of the samples was evaluated.Results All the sequencing depth of the four samples was more than1 500 ×,and the GC content of the virus seed and vaccine bulk was about 46%,indicating that the sequencing quality was high.The mutation sites and base composition of the gene sequences of virus seed and vaccine bulk were consistent before and after prodution site change,and the VAF was close.Pairwise comparison of correlation coefficients was highly correlated,and the correlation coefficients were significantly different(each R~2≥ 0.990,each P < 0.001).Conclusion NGS test showed that the changes in vaccine production process have no effect on the quality of live attenuated varicella vaccine.

Construction,expression,purification and quality identification of kanamycin resistant strain of recombinant human interleukin-1 receptor antagonist / 中国生物制品学杂志

@#Objective To construct a recombinant human interleukin-1 receptor antagonist(rhIL-1Ra)strain of kanamycin resistance,express,purify and identify rhIL-1Ra protein in order to reduce the risks of β-lactam antibiotics.Methods The ampicillin-resistant rhIL-1Ra(A-rhIL-1Ra)plasmid and PET-28a plasmid were used as templates to prepare the linearized vector and kanamycin gene fragment by PCR.The kanamycin resistant rhIL-1Ra plasmid(K-rhIL-1Ra)was constructed by homologous recombination,which was transformed into E.coli BL21(DE3)to construct the recombinant engineered bacteria after correct sequencing.The engineered bacteria were induced by IPTG and then purified by CM Bestarose Fast Flow and DEAE Bestarose Fast Flow column chromatography.The purified products were collected,and then detected for the purity by 15% SDS-PAGE,size-exclusion high-performance liquid chromatography(SEC-HPLC),and reversed-phase high-performance liquid chromatography(RP-HPLC),determined for the relative molecular mass by tandem mass spectrometry,identified for the specificity by Western blot,measured for the biological activity by reporter gene assay,and compared for the related impurities by liquid chromatography-mass spectrometry(LC-MS)analysis.Results Colony PCR and sequencing results showed that K-rhIL-1Ra plasmid was constructed correctly.The expressed K-rhIL-1Ra protein had a relative molecular mass of about 17 000,mainly existing in soluble form,and the expression amount accounted for more than 30% of the total bacterial proteins.The purity of K-rhIL-1Ra protein purified by two steps was 97% and 99%,the monomer content was 99.33%and 100%,and the chromatographic purity was 91.86% and 96.96%,respectively.The mass spectral molecular mass was consistent with that of the standard(A-rhIL-1Ra protein),and the protein reacted specifically relative with mouse antihuman IL-1Ra monoclonal antibody.The biological activity of the purified K-rhIL-1Ra protein was 1.29 × 105U/mg,and the chemical modification types of related proteins were the same as those of the standard(A-rhIL-1Ra protein).Conclusion The K-rhIL-1Ra strain was successfully constructed,and the expressed and purified protein was in line with the characteristics and quality standards of rhIL-1Ra,which lays a foundation for the study of rhIL-1Ra strain change and comparability

Isolation and phylogenetic analysis of avian infectious bronchitis virus from an imported chicken meat product in Malaysia

@#Avian infectious bronchitis (IB), a Gammacoronavirus, is a highly contagious upper respiratory disease, affecting chickens of all ages with a significant economic threat to the poultry industry. In February 2020, a specimen of imported chicken meat product was received and requested for coronavirus testing. The result was positive for the avian coronavirus, the IB virus (IBV) by molecular detection in the pre-screening test. Thus, this study aimed to isolate and characterize the IBV from the specimen. Virus isolation via egg inoculation was attempted and IBV was successfully isolated. The S1 subunit of the spike (S) gene of the IBV was amplified, sequenced, and the Basic Local Alignment Search Tool (BLAST) analysis showed that the IBV has 99% and 98% nucleotide similarity with the Malaysian and China IBVs, respectively. The phylogenetic analysis indicated that the virus belongs to the GI-19 lineage (also known as the QX strain) and is grouped with other IBVs from Malaysia and China. The GI-19 lineage is one of the primary IB strains that circulate in Malaysia. The recovery of the virus may be due to the persistence characteristic of the virus on meat; and the cold chain practices in the imported food product prolong the survival of this coronavirus. Though IBV is not identified as a hazard in chicken meat or meat products, raw food should be cooked thoroughly before being consumed. With the increase in international trade in poultry and poultry products, disease screening at the entry point and import risk analysis is crucial to ensure food safety and prevent the introduction of new viruses into Malaysia.

Characteristics of Early Cardiac Involvement in 45 Patients With Fabry Disease Monitored by Ultrasonic Cardiogram / 中山大学学报(医学科学版)

ObjectiveTo evaluate the changes in cardiac structure and ventricular function in patients with Anderson-Fabry Disease （AFD） by two-dimensional speckle tracking echocardiography （2D-STE） and to explore the characteristics of their early cardiac involvement. MethodsAll 45 patients diagnosed with AFD in this observational study underwent routine ultrasonic cardiogram （UCG） examination and 2D-STE. The patients were divided into 2 groups based on UCG measurements： with left ventricular hypertrophy （interventricular septum or posterior left ventricular wall thickness ≥12 mm） and without left ventricular hypertrophy. TomTec software was used to analyze the echocardiographic images， then the baseline data， UCG routine parameters and myocardial strain of the two groups were compared. ResultsThe study included 27 males （60.0%） and 18 females （40.0%）， with an average age of （32.33±16.11）， 17 cases （37.78%） with left ventricular hypertrophy and 28 cases （62.22%） without left ventricular hypertrophy. All patients had normal left ventricular ejection fraction （LVEF） （> 50%）. Compared with those without left ventricular hypertrophy， patients with left ventricular hypertrophy had significantly more target organ involvement， significantly higher E/A and average E/E' ratios （P < 0.05）. No statistical difference was found in global and segmental longitudinal strain （LS）， circumferential strain （CS） and radial strain （RS） of the endocardium and myocardium between the two groups （all P > 0.05）. There were lower absolute values of global and segmental LS and CS in the myocardium than in the endocardium （all P < 0.05）， and higher absolute values of LS and RS in the mid segment than in the basal and apical segments （all P < 0.05）. ConclusionsThere is no significant association between early systolic dysfunction and left ventricular wall thickness. 2D-STE strain can be used to detect AFD in the early stage. Ventricular wall myocardium exhibits more serious involvement than endocardium and mid segment was less involved than the apical and basal segments.

Pollution status and distribution characteristics of indoor air bacteria in subway stations and compartments in a city of Central South China / 环境与职业医学

Background Bacteria are the most diverse and widely sourced microorganisms in the indoor air of subway stations, where pathogenic bacteria can spread through the air, leading to increased health risks. Objective To understand the status and distribution characteristics of indoor air bacterial pollution in subway stations and compartments in a city of Central South China, and to provide a scientific basis for formulating intervention measures to address indoor air bacteria pollution in subways. Methods Three subway stations and the compartments of trains parking there in a city in Central South China were selected according to passenger flow for synchronous air sampling and monitoring. Temperature, humidity, wind speed, carbon dioxide (CO2), fine particulate matter (PM2.5), and inhalable particulate matter (PM10) were measured by direct reading method. In accordance with the requirements of Examination methods for public places-Part 3: Airborne microorganisms (GB/T 18204.3-2013), air samples were collected at a flow rate of 28.3 L·min−1, and total bacterial count was estimated. Bacterial microbial species were identified with a mass spectrometer and pathogenic bacteria were distinguished from non-pathogenic bacteria according to the Catalogue of pathogenic microorganisms transmitted to human beings issued by National Health Commission. Kruskal-Wallis H test was used to compare the subway hygiene indicators in different regions and time periods, and Bonferroni test was used for pairwise comparison. Spearman correlation test was used to evaluate the correlation between CO2 concentration and total bacterial count. Results The pass rates were 100.0% for airborne total bacteria count, PM2.5, and PM10 in the subway stations and train compartments, 94.4% for temperature and wind speed, 98.6% for CO2, but 0% for humidity. The overall median (P25, P75) total bacteria count was 177 (138,262) CFU·m−3. Specifically, the total bacteria count was higher in station halls than in platforms, and higher during morning peak hours than during evening peak hours (P<0.05). A total of 874 strains and 82 species were identified by automatic microbial mass spectrometry. The results of identification were all over 9 points, and the predominant bacteria in the air were Micrococcus luteus (52.2%) and Staphylococcus hominis (9.8%). Three pathogens, Acinetobacter baumannii (0.3%), Corynebacterium striatum (0.1%), and Staphylococcus epidermidis bacilli (2.2%) were detected in 23 samples (2.6%), and the associated locations were mainly distributed in train compartments during evening rush hours. Conclusion The total bacteria count in indoor air varies by monitoring sites of subway stations and time periods, and there is a risk of opportunistic bacterial infection. Attention should be paid to cleaning and disinfection during peak passenger flow hours in all areas.

FVB/NJ strain as a mouse model for cutaneous leishmaniasis by Leishmania (L.) amazonensis

BACKGROUND Leishmaniases encompass a spectrum of neglected diseases caused by parasites of the genus Leishmania, grouped in two forms: tegumentary and visceral leishmaniasis. OBJECTIVES In this study, we propose Friend Virus B NIH Jackson (FVB/NJ) mouse strain as a new experimental model of infection with Leishmania (Leishmania) amazonensis, the second most prevalent agent of tegumentary leishmaniasis in Brazil. METHODS AND FINDINGS We performed in vitro infections of FVB/NJ macrophages and compared them with BALB/c macrophages, showing that BALB/c cells have higher infection percentages and a higher number of amastigotes/cell. Phagocytosis assays indicated that BALB/c and FVB/NJ macrophages have similar capacity to uptake parasites after 5 min incubations. We also investigated promastigotes' resistance to sera from FVB/NJ and BALB/c and observed no difference between the two sera, even though FVB/NJ has a deficiency in complement components. Finally, we subcutaneously infected FVB/NJ and BALB/c mice with 2 × 106 parasites expressing luciferase. Analysis of lesion development for 12 weeks showed that FVB/NJ and BALB/c mice have similar lesion profiles and parasite burdens. MAIN CONCLUSIONS This work characterises for the first time the FVB/NJ mouse as a new model for tegumentary leishmaniasis caused by Leishmania (L.) amazonensis.

A Critical Review of Echocardiographic Findings for Diagnosing Cardiac Amyloidosis

Abstract This article provides a critical review of the diagnostic value of several echocardiographic findings in cardiac amyloidosis (CA). The importance of early and accurate detection of CA is emphasized, considering its challenging diagnosis and the need for a high index of suspicion by clinicians. Echocardiography is often the first choice for imaging assessment of cardiac structure and function when CA is suspected. The article encompasses several conventional echocardiographic features and speckle-tracking echocardiography-derived deformation parameters. Some of these indexes are grouped together to form scores, which can improve the accuracy of diagnosing CA. However, particularly in earlier stages, echocardiography has low specificity to distinguish amyloid from other hypertrophic phenotypes, highlighting the need for correlation with clinical red flags, laboratory tests, and additional cardiac imaging modalities.

Transcriptomic analysis of A549 cells infected with ON1 genotype of human respiratory syncytial virus subtype A isolated in Beijing / 中华微生物学和免疫学杂志

Objective:To analyze the differentially expressed genes of human respiratory syncytial virus (RSV) subtype A genotype ON1, a predominant genotype in Beijing, after infecting A549 cells using transcriptomic sequencing, and provide potential targets for RSV prevention and treatment.Methods:A local strain (61397-ON1) identified by whole-genome sequencing as ON1 genotype of RSV subtype A was selected to infect A549 cells. Total mRNA was extracted, and the differentially expressed genes in infected and uninfected A549 cells were screened by transcriptomic sequencing. GO analysis and KEGG pathway analysis were performed. Besides, six genes with differential expression ratio greater than two times were randomly selected for qRT-PCR verification.Results:There were 1 632 differentially expressed genes between infected and uninfected A549 cells, of which 807 genes were up-regulated and 825 genes were down-regulated. The differentially expressed genes were mainly involved in immune response-related biological processes such as cytokine response and positive regulation of MAPK cascades, and were enriched in MAPK signaling pathway, NOD-like receptor signaling pathway, p53 signaling pathway, TNF signaling pathway, IL-17 signaling pathway and NF-κB signaling pathway. The results of qRT-PCR for six differentially expressed genes were consistent with the trend of transcriptome data.Conclusions:The differentially expressed genes of RSV A subtype ON1 genotype after infecting A549 cells are mainly involved in cytokine response and immune-related signaling pathways. This study provides basic data for further study of the molecular mechanism of RSV infection and the development of prevention and treatment strategies.

Colorimetric Determination of Antioxidant Capacity by Peroxidase Mimics Based on Ruthenium Nanoparticles Supported on Carbon Nanosheets / 分析化学

Lattice strain ruthenium nanoparticles uniformly and stably supported on nitrogen-modified carbon nanosheets(RuNPs/NC)were prepared via simple wet-chemical and subsequent pyrolysis method.The nitrogen doped NC could effectively improve their uniform dispersion and lattice compression of RuNPs.Through changing the pyrolysis temperature,the nitrogen content,types and degree of lattice strain of RuNPs could be effectively tuned,which could be used to adjust and control their peroxidase-like activity.The as-prepared RuNPs/NC-900 exhibited highest peroxidase-like activity,and could catalyze the oxidation of 3,3′,5,5′-tetramethylbenzidine(TMB)to produce a blue product with the maximum absorption at 652 nm in the presence of H2O2.The steady-state kinetic analysis indicated that the reaction catalyzed by RuNPs/NC followed the Michaelis-Menten kinetic model.Tannic acid(TA),gallic acid(GA)and ascorbic acid(AA)could effectively inhibit the RuNPs/NC-H2O2-triggered chromogenic reaction of TMB,resulting in color fading and decrease in absorbance.Based on this,a sensitive and accurate system was constructed for detection of TA,GA and AA.The detection limits(3σ/S)for TA,GA and AA were 0.014,0.014 and 0.29 μmol/L,respectively.This study not only developed a colorimetric sensing method based on RuNPs/NC nanozyme but also offered a new approach for the sensitive detection of antioxidants in food.

Comparison of the predictive value of new simplified insulin resistance assessment indexes in identifying left ventricular subclinical dysfunction in T2DM patients / 解放军医学杂志

Objective To investigate the predictive value of new simplified insulin resistance(IR)assessment indexes in identifying subclinical left ventricular systolic function impairment in patients with type 2 diabetes mellitus(T2DM).Methods A total of 150 T2DM patients with preserved left ventricular ejection fraction(LVEF≥50%)who were admitted to Department of Endocrinology of the First Affiliated Hospital of Air Force Medical University from June 2021 to December 2021 were retrospectively analyzed.All patients underwent two-dimensional speckle tracking echocardiography to measure left ventricular global longitudinal strain(GLS).According to GLS value,the subjects were divided into the normal group(GLS≥18%group,n=80)and the impaired group(GLS<18%group,n=70).Some new simplified IR assessment indicators were calculated and compared between the two groups,including body mass index(BMI),TG/HDL-C ratio,triglyceride-glucose(TyG)index,TyG-BMI index,TyG-WHR and metabolic score for IR(METS-IR).Correlation between the GLS and the new simplified IR assessment indexes was analyzed.The receiver operating characteristic(ROC)curve was used to analyze the diagnostic efficacy of different simplified IR assessment indexes,with the area under the curve(AUC)calculated.Furthermore,according to whether the subjects were complicated with hypertension,binary logistics regression analysis was performed to explore the independent correlation between the simplified IR assessment index and GLS<18%.Results Total 150 were included with aged(54.5±13.7)years with 96(64.0%)men and 54(36.0%)women.Compared with the GLS≥18%group,the TG/HDL-C ratio,TyG index,TyG-BMI,and METS-IR of subjects in the GLS<18%group were significantly increased(P<0.05).Pearson correlation analysis showed that TG/HDL-C ratio,TyG index,TyG-BMI,TyG-WHR,and METS-IR were negatively correlated with GLS(P<0.05).ROC analysis showed that TyG index had a certain predictive value for the evaluation of GLS<18%(AUC=0.678,95%CI 0.591-0.765,P<0.001).Stratification based on hypertension and further adjusting for confounding factors,TyG index remains significantly associated with GLS<18%(OR=3.249,95%CI 1.045-10.103,P=0.042).Conclusions The novel simplified insulin resistance evaluation indexes are closely associated with left ventricular subclinical systolic dysfunction in T2DM patients with preserved ejection fraction.TyG index is an effective index to identify left ventricular subclinical dysfunction in these populations.

The influence of static mechanical strain on osteoclastogenic gene expression of HPDLSCs and PPDLSCs / 实用口腔医学杂志

Objective:To explore the influence of static mechanical strain(SMS)on the osteoclastogenic gene expression of healthy periodontal ligment stem cells(HPDLSCs)and periodontitis periodontal ligment stem cells(PPDLSCs).Methods:HPDLSCs and PP-DLSCs were respectively isolated and cultured by low density in vitro.The expression of mesenchymal stem cell markers were detected by flow cytometry.Then,6％,8％,10％,12％and 14％SMS were respectively loaded to the HPDLSCs and PPDLSCs by Flexcell Tension Unit,and the expression of RANKL and C-fos was detected by real time RT-PCR.Results:Both HPDLSCs and PPDLSCs strongly expressed the mesenchymal stem cell markers STRO-1,CD146,CD90 and CD29,and higher expression of the above markers was found in HPDLSCs compared with PPDLSCs(P＜0.05).The expression of RANKL and C-fos in PPDLSCs was more obvious than that in HPDLSCs without SMS loading(P＜0.05).For HPDLSCs,the SMS of 14％induced significant up-regulation of RANKL and C-fos(P＜0.05),while no alteration was confirmed for the above osteoclastogenic genes when the SMS≤ 12％(P＞O.05).In addition,the expression of RANKL and C-fos was up-regulated significantly in PPDLSCs when the SMS≥ 10％(P＜0.05),and the expression of the above genes was not activated when the SMS ≤8％.Conclusion:HPDLSCs and PPDLSCs response differently to SMS,and ex-cessive SMS may lead to enhanced expression of osteoclastogenic genes in PPDLSCs.

Effects of Different Running Speeds on Tissue-Level Failure Strain in Rat Femoral Cortical Bone / 医用生物力学

Objective To predict the tissue-level failure strain of the cortical bone and discuss the effects of different running speeds on the mechanical properties of rat femoral cortical bone.Methods The threshold for cortical bone tissue-level failure strain was assigned,and fracture simulation under three-point bending was performed on a rat femoral finite element model.The predicted load-displacement curves in each simulation were compared and fitted with the experimental data to back-calculate the tissue-level failure strain.Results The cortical bone tissue-level failure strains at different running speeds were statistically different,which indicated that different running speeds had certain impacts on the micromechanical properties of the cortical bone structures.At a running speed of 12 m/min,the cortical bone structure expressed the greatest tissue-level failure strain,and at a running speed of 20 m/min,the cortical bone structure expressed the lowest tissue-level failure strain.Conclusions Based on the changing trends of tissue-level failure strain and in combination with the changes in macro-level failure load and tissue-level elastic modulus of cortical bone structures,the effects of different running speeds on the mechanical properties of cortical bone structures were discussed in this study.The appropriate running speed for improving the mechanical properties of the cortical bone was explored,thereby providing a theoretical basis for improving bone strength through running exercises.

Diagnostic value of breast cancer with 2D ultrasound features combined with ultrasonic elastic strain rate ratio and correlation analysis with pathological prognostic indicators / 中国医学物理学杂志

Objective To analyze the diagnostic value of two-dimensional(2D)ultrasound features combined with ultrasonic elastic strain rate ratio(SR)for breast cancer and discuss their correlations with pathological prognostic indicators.Methods The clinical data of 265 patients with breast cancer admitted to the 2nd Affiliated Hospital of Chengdu Medical College from January 2020 to December 2021 were analyzed retrospectively.Through pathological examination,171 cases were diagnosed with benign lesions(benign group)and 94 cases with malignant lesions(malignant group).The 2D ultrasound and ultrasound elastography imaging data were collected and compared for the two groups in terms of ultrasound appearance and SR.The positive rates of estrogen receptor(ER),progesterone receptor(PR),and proto-oncogene(CerbB-2)were recorded.Receiver operating characteristic(ROC)curve was drawn to analyze the diagnostic efficiency of 2D ultrasound and SR for breast cancer;and Pearman correlation analysis was conducted to assess the correlations between 2D ultrasound features/SR and ER/PR/CerbB-2.Results The 2D ultrasound features such as spicule sign,posterior echo attenuation,microcalcification,lymph node metastasis,and abundant blood flow were more common in malignant group,and the SR was significantly higher than that in benign group(P<0.05).The positive rates of ER,PR and CerbB-2 in malignant group were 59.57%,75.53%and 47.87%,respectively,significantly higher than those in benign group(P<0.05).ROC curve analysis showed that the AUC values of 2D ultrasound,SR,and their combination for breast cancer diagnosis were 0.586,0.743,and 0.761,respectively,indicating a significantly higher diagnostic efficiency of the combined detection than 2D ultrasound or SR alone(P<0.05).The occurrences of spicule sign and posterior echo attenuation and SR were higher in ER-positive patients than in ER-negative patients(P<0.05);lymph node metastasis was more prevalent in PR-positive patients,and their SR was higher than PR-negative patients(P<0.05);CerbB-2 positive patients had more microcalcifications and higher SR value as compared with CerbB-2 negative patients(P<0.05).Pearman correlation analysis revealed that there were positive correlations between 2D ultrasound features such as spicule sign/posterior echo attenuation and ER,lymph node metastasis and PR,microcalcification and CerbB-2,SR and ER/PR/CerbB-2(P<0.05).Conclusion The combination of 2D ultrasound features and SR provides reliable imaging information for the diagnosis of breast cancer.The spicule sign,posterior echo attenuation,lymph node metastasis,microcalcification and SR are correlated to the pathological prognostic indicators(ER,PR,and CerbB-2).

Application of Cardiac Magnetic Resonance in the Evaluation of Left Atrium / 中国医学影像学杂志

As the continuation of the left ventricle,the left atrium and left ventricle interact and play an important role in the function of the whole heart.At present,there are many techniques to evaluate the atrial structure and function,but the left atrial structure is complex and the myocardium is thin,which brings some challenges to the relevant evaluation.This paper introduces the parameters,precautions and relevant clinical applications in the process of left atrial evaluation from the aspects of myocardial strain and delayed enhancement.