Objective To explore the polymorphism of tyrosinase (TYR) and melanocortin 1 receptor (MC1R) genes and their mRNA expression levels in relation to coat-color phenotypes in guinea pigs, providing genetic markers for locating dominant traits in guinea pigs. Methods A total of 57 self-bred ordinary-level guinea pigs were selected and divided into three groups based on coat color: white (n=22), variegated (n=22) and black (n=13). The guinea pigs were euthanized with an overdose of pentobarbital sodium via intraperitoneal injection. DNA was then extracted from the dorsal skin tissue. Polymorphism in the coding sequence (CDS) of the exons of the TYR and MC1R genes in each group was detected by cloning and sequencing. The mRNA expression of the two genes in skin tissues was detected by real-time fluorescent quantitative PCR to investigate the relationship between these genes and guinea pig coat color. Results A single nucleotide polymorphism (SNP) site was found in the CDS region of TYR exon Ⅰ, where the base A was replaced by G. All white guinea pigs had the G/G genotype for TYR, while no deep-colored (variegated and black) guinea pigs exhibited the G/G genotype for TYR. Most deep-colored guinea pigs had the A/A genotype, and a few had A/G genotype. The A/A genotype frequency in black guinea pigs was higher than in variegated guinea pigs. A 2 760 bp sequence deletion was identified in the exon of the MC1R gene, marked as the - gene, with non-deleted samples marked as N gene. Most white guinea pigs had the -/- genotype for MC1R, variegated guinea pigs mainly had the -/N genotype, and black guinea pigs mainly had the N/N genotype, with a few showing the -/N. The TYR gene expression level was higher in white guinea pigs, lower in variegated guinea pigs, and intermediate in black guinea pigs, but there was no significant difference among the three groups (P>0.05). The MC1R gene expression level in white guinea pigs was extremely low, while both variegated and black guinea pigs showed significantly higher levels than white guinea pigs (P<0.01). Black guinea pigs showed significantly higher levels than variegated guinea pigs (P<0.05). ConclusionThe TYR and MC1R genes synergistically regulate coat color of guinea pigs. The G-site mutation in the TYR gene may lead to albinism, and the change of N-site in the MC1R gene affects the depth of the coat color.

BACKGROUND:Carnosic acid,a bioactive compound found in rosemary,has been shown to reduce inflammation and reactive oxygen species(ROS).However,its mechanism of action in osteoclast differentiation remains unclear. OBJECTIVE:To investigate the effects of carnosic acid on osteoclast activation,ROS production,and mitochondrial function. METHODS:Primary bone marrow-derived macrophages from mice were extracted and cultured in vitro.Different concentrations of carnosic acid(0,10,15,20,25 and 30 μmol/L)were tested for their effects on bone marrow-derived macrophage proliferation and toxicity using the cell counting kit-8 cell viability assay to determine a safe concentration.Bone marrow-derived macrophages were cultured in graded concentrations and induced by receptor activator of nuclear factor-κB ligand for osteoclast differentiation for 5-7 days.The effects of carnosic acid on osteoclast differentiation and function were then observed through tartrate-resistant acid phosphatase staining,F-actin staining,H2DCFDA probe and mitochondrial ROS,and Mito-Tracker fluorescence detection.Western blot and RT-PCR assays were subsequently conducted to examine the effects of carnosic acid on the upstream and downstream proteins of the receptor activator of nuclear factor-κB ligand-induced MAPK signaling pathway. RESULTS AND CONCLUSION:Tartrate-resistant acid phosphatase staining and F-actin staining showed that carnosic acid dose-dependently inhibited in vitro osteoclast differentiation and actin ring formation in the cell cytoskeleton,with the highest inhibitory effect observed in the high concentration group(30 μmol/L).Carnosic acid exhibited the most significant inhibitory effect during the early stages(days 1-3)of osteoclast differentiation compared to other intervention periods.Fluorescence imaging using the H2DCFDA probe,mitochondrial ROS,and Mito-Tracker demonstrated that carnosic acid inhibited cellular and mitochondrial ROS production while reducing mitochondrial membrane potential,thereby influencing mitochondrial function.The results of western blot and RT-PCR revealed that carnosic acid could suppress the expression of NFATc1,CTSK,MMP9,and C-fos proteins associated with osteoclast differentiation,and downregulate the expression of NFATc1,Atp6vod2,ACP5,CTSK,and C-fos genes related to osteoclast differentiation.Furthermore,carnosic acid enhanced the expression of antioxidant enzyme proteins and reduced the generation of ROS during the process of osteoclast differentiation.Overall,carnosic acid exerts its inhibitory effects on osteoclast differentiation by inhibiting the phosphorylation modification of the P38/ERK/JNK protein and activating the MAPK signaling pathway in bone marrow-derived macrophages.

Objective To observe the expression and localization of group Ⅰ metabotropic glutamate receptors (mGluR1/ 5) in rat superior cervical ganglion (SCG) and the effect of chronic intermittent hypoxia (CIH) on mGluR1/ 5 protein level. Methods Twelve male SD rats were randomly divided into control group(Ctrl)and CIH group(CIH), 6 rats in each group. After 6 weeks of modeling, the effect of CIH on mGluR1/ 5 protein level was detected by Western blotting, the expression and distribution of mGluR1/ 5 in SCG were detected by immunohistochemistry and double-immunofluorescent staining. Results mGluR1/ 5 was expressed in rat SCG. mGluR1 was distributed in neurons and small intensely fluorescent (SIF) cells, but not in satellite glial cells (SGCs), nerve fibers and blood vessels, whereas mGluR5 was mainly distributed in nerve fibers and a little in neurons, but not in SGCs, SIF cells and blood vessels. CIH increased the protein levels of mGluR1/ 5 (P<0. 01) in rat SCG. Conclusion Both mGluR1 and mGluR5 are expressed in the rat SCG, but their distribution are different, and the increased protein levels of both may be involved in CIH-induced hypertension.

Objective To explore the relevant factors of new-onset conduction disturbance(NOCD)after transcatheter aortic valve replacement(TAVR),such as anatomical structure,device type,surgical strategies,etc.,discover relevant predictive factors,and establish a predictive model to assess the risk of conduction blockages.Methods From January 2016 to March 2022,clinical data of symptomatic patients with severe aortic valve stenosis or severe regurgitation who underwent TAVR at Xiangya Second Hospital of Central South University were collected through the hospital information system and imaging database.ECG,echocardiography,CTA,surgical materials,etc.,were extracted and analyzed by specialists.SPSS software was used for statistical analysis,and a multi-factor regression prediction model for NOCDwas built.Results A total of 184 patients were included,the occurrence rate of NOCD after TAVR was 31.0%,pure regurgitation patients'NOCD occurrence rate was 63.6%(7/11).The NOCD group had a larger aortic angles[(57.7±10.3)°vs.(52.0±9.0)°,P＜0.001],larger Oversizing[(129±28)%vs.(120±21)%,P=0.018],deeper implantation depth[(7.2±5.1)mm vs.(4.8±4.2)mm,P=0.001],and higher pure regurgitation patients'proportion[12.3%vs.3.1%,P=0.037]than the non-NOCD group.Multifactorial Logistic regression analysis indicated that an aorta angle＞54.5°(OR 3.78,95%CI 1.86-7.63,P＜0.001)or implantation depth＞5.7 mm(OR 3.39,95%CI 1.68-6.85,P＜0.001)are independent risk factors for new onset conduction disturbances after TAVR,and a predictive model was established with aortic angle,implantation depth,and Oversizing ratio as variables.The receiver operating characteristics curve showed area under ROC curve 0.709,95%CI 0.623-0.795,predicting NOCD after TAVR.Conclusions A retrospective analysis carried out at a single center discovered that the aortic angle in the NOCD group was larger than that in the non-NOCD group,the Oversizing ratio was higher,the implantation location was deeper,and there was a higher proportion of patients with pure regurgitation lesions.An aortic angle greater than 54.5°or an implantation depth more than 5.7 mm were identified as independent risk factors for NOCD after TAVR.

Background and aim:Hepatic ischemia-reperfusion injury(IRI)is a significant challenge in liver trans-plantation,trauma,hypovolemic shock,and hepatectomy,with limited effective interventions available.This study aimed to investigate the role of leukocyte cell-derived chemotaxin 2(LECT2)in hepatic IRI and assess the therapeutic potential of Lect2-short hairpin RNA(shRNA)delivered through adeno-associated virus(AAV)vectors. Materials and methods:This study analyzed human liver and serum samples from five patients under-going the Pringle maneuver.Lect2-knockout and C57BL/6J mice were used.Hepatic IRI was induced by clamping the hepatic pedicle.Treatments included recombinant human LECT2(rLECT2)and AAV-Lect2-shRNA.LECT2 expression levels and serum biomarkers including alanine aminotransferase(ALT),aspartate aminotransferase(AST),creatinine,and blood urea nitrogen(BUN)were measured.Histological analysis of liver necrosis and quantitative reverse-transcription polymerase chain reaction were performed. Results:Serum and liver LECT2 levels were elevated during hepatic IRI.Serum LECT2 protein and mRNA levels increased post reperfusion.Lect2-knockout mice had reduced weight loss;hepatic necrosis;and serum ALT,AST,creatinine,and BUN levels.rLECT2 treatment exacerbated weight loss,hepatic necrosis,and serum biomarkers(ALT,AST,creatinine,and BUN).AAV-Lect2-shRNA treatment significantly reduced weight loss,hepatic necrosis,and serum biomarkers(ALT,AST,creatinine,and BUN),indicating thera-peutic potential. Conclusions:Elevated LECT2 levels during hepatic IRI increased liver damage.Genetic knockout or shRNA-mediated knockdown of Lect2 reduced liver damage,indicating its therapeutic potential.AAV-mediated Lect2-shRNA delivery mitigated hepatic IRI,offering a potential new treatment strategy to enhance clinical outcomes for patients undergoing liver-related surgeries or trauma.

A rapid analytical method for determination of paraquat and diquat in tea samples was established by improving the QuEChERS pre-treatment method combined with ultra-high performance liquid chromatography-tandem quadrupole mass spectrometry(UPLC-MS/MS).Four kinds of tea powder were extracted by using acetonitrile-0.1％formic acid solution(3∶7,V/V)and ultrasonic treatment,and the supernatant was purified with 400 mg C18 and 400 mg PSA and separated on hydrophilic HILIC(100 mm×2.1 mm,1.8 μm)column by using 0.1％formic acid aqueous solution(Containing 5 mmol/L ammonium formate)and acetonitrile as mobile phases.In the electrospray ion source positive ion mode(ESI+),multiple reaction monitoring scanning technology(MRM)was used for determination,and the matrix-matched standard solution external standard method was used for quantitative analysis.The results showed that paraquat obtained good linear relationship in the content range of 0.18-200 μg/kg and diquat obtained good linear relationship in the content range of 0.36-200 μg/kg,and the correlation coefficients(R2)were 0.9939-0.9976 and 0.9959-0.9987,respectively.The limits of detection(LODs)were 0.06 and 0.12 μg/kg,and the limits of quantitation(LOQs)were 0.18 and 0.36 μg/kg,respectively.The average spiked recoveries for tea samples varied from 84.4％to 128.8％,with the relative standard deviations(RSDs)from 0.6％to 13.5％.The method was simple and efficient,with accurate quantification ability and low detection limit,which could realize efficient determination of paraquat and diquat in tea samples.

Lung cancer is one of the malignant tumors with the highest mortality and the fastest growing incidence,which seriously threatens human life and health.With the popularization of low-dose spiral CT and the enhancement of public awareness of physical examination,more and more ground-glass nodules have been detected.Accumulating studies have shown that for patients with nodules diameter≤2 cm and ground-glass opacity≥50% ,under the condition of ensuring the cutting edge,thoracoscopic sublobectomy or subsegmentectomy can more effectively preserve the lung function of patients,and has gradually become the recommended surgical method.In recent years,with the continuous improvement of thoracoscopic surgery technology,thoracoscopic subsegmentectomy and combined subsegmentectomy have been gradually carried out.Compared with lobectomy and segmentectomy,subsegmental resection can retain more normal lung tissue and reduce the loss of lung function under the condition of ensuring the safe cutting edge.However,thoracoscopic subsegmental resection requires a higher level of surgical technique and anatomical knowledge for the operator,and is rarely reported in relevant literature.Therefore,this article reviews the progress of anatomical subsegmentectomy and combined subsegmentectomy in the treatment of early non-small cell lung cancer.

Objective To investigate the clinical characteristics and prognosis of pneumococcal meningitis(PM),and drug sensitivity of Streptococcus pneumoniae(SP)isolates in Chinese children.Methods A retrospective analysis was conducted on clinical information,laboratory data,and microbiological data of 160 hospitalized children under 15 years old with PM from January 2019 to December 2020 in 33 tertiary hospitals across the country.Results Among the 160 children with PM,there were 103 males and 57 females.The age ranged from 15 days to 15 years,with 109 cases(68.1% )aged 3 months to under 3 years.SP strains were isolated from 95 cases(59.4% )in cerebrospinal fluid cultures and from 57 cases(35.6% )in blood cultures.The positive rates of SP detection by cerebrospinal fluid metagenomic next-generation sequencing and cerebrospinal fluid SP antigen testing were 40% (35/87)and 27% (21/78),respectively.Fifty-five cases(34.4% )had one or more risk factors for purulent meningitis,113 cases(70.6% )had one or more extra-cranial infectious foci,and 18 cases(11.3% )had underlying diseases.The most common clinical symptoms were fever(147 cases,91.9% ),followed by lethargy(98 cases,61.3% )and vomiting(61 cases,38.1% ).Sixty-nine cases(43.1% )experienced intracranial complications during hospitalization,with subdural effusion and/or empyema being the most common complication[43 cases(26.9% )],followed by hydrocephalus in 24 cases(15.0% ),brain abscess in 23 cases(14.4% ),and cerebral hemorrhage in 8 cases(5.0% ).Subdural effusion and/or empyema and hydrocephalus mainly occurred in children under 1 year old,with rates of 91% (39/43)and 83% (20/24),respectively.SP strains exhibited complete sensitivity to vancomycin(100% ,75/75),linezolid(100% ,56/56),and meropenem(100% ,6/6).High sensitivity rates were also observed for levofloxacin(81% ,22/27),moxifloxacin(82% ,14/17),rifampicin(96% ,25/26),and chloramphenicol(91% ,21/23).However,low sensitivity rates were found for penicillin(16% ,11/68)and clindamycin(6% ,1/17),and SP strains were completely resistant to erythromycin(100% ,31/31).The rates of discharge with cure and improvement were 22.5% (36/160)and 66.2% (106/160),respectively,while 18 cases(11.3% )had adverse outcomes.Conclusions Pediatric PM is more common in children aged 3 months to under 3 years.Intracranial complications are more frequently observed in children under 1 year old.Fever is the most common clinical manifestation of PM,and subdural effusion/emphysema and hydrocephalus are the most frequent complications.Non-culture detection methods for cerebrospinal fluid can improve pathogen detection rates.Adverse outcomes can be noted in more than 10% of PM cases.SP strains are high sensitivity to vancomycin,linezolid,meropenem,levofloxacin,moxifloxacin,rifampicin,and chloramphenicol.[Chinese Journal of Contemporary Pediatrics,2024,26(2):131-138]

Aim To explore the antimicrobial activity of a novel R-type phage tail-like bacteriocin(PTLB)secreted by Enterobacter cloacae SHAMU191747 a-gainst methicillin-resistant Staphylococcus aureus(MR-SA).Methods Antagonistic activity of E.cloacae SHAMU191747 against MRS A was detected by LB agar plate antagonistic test and LB broth micro-fermentation test.The crude extract of fermentation supernatant of E.cloacae SHAMU191747 was prepared by ultra-high-speed centrifugation and density gradient centrifuga-tion.The novel R-type PTLB in the crude extract was detected by transmission electron microscopy.The an-timicrobial activity of the crude extract against MRSA was verified by LB agar plate spot-seeding method.The molecular weight of the novel R-type PTLB was detected by SDS-PAGE electrophoresis.Results E.cloacae SHAMU191747 secreted a novel R-type PTLB,and had a strong antagonistic effect on MRSA.The no-vel R-type PTLB had a molecular weight of approxi-mately 35 ku and could efficiently kill MRSA.The physical dimensions of its tail-sheath-uncontracted functional molecules were(142.7±4.3)×(13.8±0.6)nm,and those of the tail-sheath-contracted non-functional molecules were(57.7±1.2)×(20.8±1.5)nm.Conclusions The novel R-type PTLB pro-duced by E.cloacae SHAMU191747 can efficiently kill MRSA,and has the potential to be developed into a novel antimicrobial drug with great prospects for clini-cal application.

Patients with severe trauma require an extremely timely treatment and transfusion plays an irreplaceable role in the emergency treatment of such patients. An increasing number of evidence-based medicinal evidences and clinical practices suggest that patients with severe traumatic bleeding benefit from early transfusion of low-titer group O whole blood or hemostatic resuscitation with red blood cells, plasma and platelet of a balanced ratio. However, the current domestic mode of blood supply cannot fully meet the requirements of timely and effective blood transfusion for emergency treatment of patients with severe trauma in clinical practice. In order to solve the key problems in blood supply and blood transfusion strategies for emergency treatment of severe trauma, Branch of Clinical Transfusion Medicine of Chinese Medical Association, Group for Trauma Emergency Care and Multiple Injuries of Trauma Branch of Chinese Medical Association, Young Scholar Group of Disaster Medicine Branch of Chinese Medical Association organized domestic experts of blood transfusion medicine and trauma treatment to jointly formulate Chinese expert consensus on blood support mode and blood transfusion strategies for emergency treatment of severe trauma patients ( version 2024). Based on the evidence-based medical evidence and Delphi method of expert consultation and voting, 10 recommendations were put forward from two aspects of blood support mode and transfusion strategies, aiming to provide a reference for transfusion resuscitation in the emergency treatment of severe trauma and further improve the success rate of treatment of patients with severe trauma.