The top 100 most cited articles on intramedullary nail fixation from 2018-2022: a bibliometric and visualized analysis

OBJECTIVE

Intramedullary nails are commonly used for the purposes of internal fixation in the repair of tubular bone fractures, allowing for optimal fixation while minimizing intraoperative bleeding, surgical incision size, and associated stress. These nails are thus often utilized to repair hip and peripheral fractures, femur fractures, tibial fractures, humerus fractures, and clavicle fractures. Recent life expectancy increases, rising economic standards, and technological innovations have led to the application of a wider range of materials and techniques in the context of orthopedic device production, further expanding the clinical indications for intramedullary nailing. Despite the growing importance of this technique, there is currently a lack of any bibliometric or visual analyses that provide a robust overview of recent progress in the intramedullary nailing research space. Accordingly, this study was developed to succinctly and comprehensively summarize the current research status and major hotspots in this field through a bibliometric review of major relevant scientific articles focused on intramedullary nailing published in recent years.

MATERIALS AND METHODS

For this analysis, the top 100 most-cited articles focused on intramedullary nails published between 2018 and 2022 were identified through a search of the Web of Science Core Collection database. Countries, institutions, journals, and other specific parameters associated with these articles were then analyzed using tools including CiteSpace, VOS-viewer, Origin, and SCImago Graphica in an effort to more clearly define the latest trends in the intramedullary nail-related research space.

RESULTS

The top 3 most-cited articles related to intramedullary nailing over the past five years were "Antibacterial and immunogenic behavior of silver coatings on additively manufactured porous titanium", "Diaphyseal long bone nonunions - types, etiology, economics, and treatment recommendations", and "Epidemiology, treatment, and mortality of trochanteric and subtrochanteric hip fractures: data from the Swedish fracture register", all of which were published in 2018, respectively exhibiting 93, 83, and 81 citations. Of the 100 most-cited intramedullary nailing-related articles, 38, 20, and 12 were respectively published by researchers from the USA, China, and the UK, while research groups from Italy and Spain each published 7 articles. Four of this field's most highly cited articles were published by individuals affiliated with the US-based University of California System and the University System of Ohio. Of the 15 journals that published the largest number of these top 100 articles, the "Injury International Journal of The Care of The Injured" and the "Journal of Orthopaedic Trauma" published 9 manuscripts each, which was more than any other journal, while the "Journal of Orthopaedic Surgery" and the "Journal of Pediatric Orthopaedics" published 7 each. In total, 73 highly cited articles focused on utilizing intramedullary nailing in orthopedic applications. Rozbruch SR from the USA published 3 high-quality articles in this research space, while the Chinese researchers Chang Shi Min, Du Shou Chao, Hou Zhi Yong, and Hu Sun Jun exhibited a total linkage strength of 21 in global interaction analyses. The most common keywords associated with intramedullary nail-related research identified in these analyses included "Hip fracture", "Nonunion", "Limb lengthening", "Proximal humeral fractures", "Additive manufacturing", "Induced membrane", and "Endoprosthetic replacement". Promising areas of potential future research focus may include "Limb reconstruction", "Pediatric deformity", and "Congenital femoral deficiency".

CONCLUSIONS

This analysis revealed that the highest volume of high-impact research output focused on intramedullary nailing over the past 5 years has been produced by the USA, followed by China and the UK. The most influential journals in this research space were Injury International Journal of The Care of The Injured and the Journal of Orthopaedic Trauma, while the institutions associated with the most highly cited articles were the University of California System and the University System of Ohio. Intramedullary nailing is commonly utilized to treat intertrochanteric fractures and other tubular bone fractures. In the future, the application of augmented and virtual reality technologies may help shorten the learning curve for orthopedic surgeons and trauma surgeons who are learning intramedullary nailing-related techniques, and the combination of intramedullary nailing with antibacterial drugs, metal alloys, 3D navigation, and sensor devices may help improve patient outcomes.

Diagnostic efficacy of lung ultrasound in cardiogenic pulmonary edema: a systematic review and meta-analysis

OBJECTIVE

This meta-analysis was performed to evaluate the diagnostic efficacy of lung ultrasound (LUS) in cardiogenic pulmonary edema.

MATERIALS AND METHODS

An electronic search of databases, including MEDLINE, Embase, PubMed, and Web of Science, was performed to collect clinical studies on ultrasound diagnosis of cardiogenic pulmonary edema from inception to 23 March 2023. The number of patients with true-positive, true-negative, false-positive, and false-negative cardiogenic pulmonary edema diagnosed by LUS was collected, and the R package was used to analyze the diagnostic efficacy of LUS.

RESULTS

Nine pieces of literature were finally included with 2,097 participants, including 1,047 patients with cardiogenic heart failure. Across the nine included papers, the pooled sensitivity of LUS in the included studies was 0.92 (95% CI: 0.84, 0.97) with a maximum sensitivity of 0.99 (95% CI: 0.96 to 1.00) and a minimum of 0.59 (95% CI: 0.50, 0.68). The pooled specificity of the included studies was 0.87 (95% CI: 0. 82, 0.91) with a maximum specificity of 0.93 (95% CI: 0.90-0.95) and a minimum of 0.80 (95% CI: 0.67, 0.89). The pooled AUC was 0.93 (95% CI: 0.84 to 0.97), suggesting a high diagnostic value of LUS in cardiogenic pulmonary edema.

CONCLUSIONS

Lung ultrasound offers a good diagnostic efficacy for cardiogenic pulmonary edema. Further standardization of the examination method is required to provide a reference for the clinical use of LUS.

[Detection and clinical application of HIV-1 DNA]

The persistence of the HIV-1 reservoir is still the main obstacle to the cure of HIV. In clinical research, reliable biomarkers are needed to label it. HIV-1 DNA can be continuously detected in the HIV-1 reservoir. It has significant application value in diagnosing HIV-1 infection, the timing of antiretroviral therapy, the prediction of virus rebound, and monitoring treatment effects. The detection technology based on polymerase chain reaction (PCR) is the most commonly used HIV-1 DNA detection method in clinical practice. The continuous innovation and advancement of technology can accurately detect the total, integrated, and unintegrated HIV-1 DNA in infected cells using qualitative or quantitative methods. Different forms of HIV-1 DNA in infected cells have been increasingly reported as biomarkers in HIV infection monitoring and AIDS treatment-related research. This article reviews the progress of HIV-1 DNA.

[Pyroptosis of lens epithelial cells in diabetic cataract]

Objective: To investigate the possible role of pyroptosis of lens epithelial cells (LECs) in the occurrence of diabetic cataract. Methods: Experimental research. A total of 70 cataract lens anterior capsule and aqueous humor samples were obtained from 70 eyes (70 patients) with cataracts in the operation room of Tianjin Medical University Eye Hospital between March 2020 and November 2020. Patients were divided into the non-diabetic and diabetic groups, with 35 patients (35 eyes) in each group. The expressions of Nod like receptor protein 3 (NLRP3), cysteine-aspartic proteases 1 (caspase-1) and Gasdermin D protein (GSDMD) in the lens anterior capsule were detected by Western blotting, real-time quantitative PCR and immunohistochemical staining. Interleukin (IL)-1β and IL-18 inaqueous humor were detected by enzyme-linked immunosorbent assay (ELISA). The independent sample t-test was used for statistical analysis. Results: The age was (70±9) years in the diabetic group and (71±8) years in the non-diabetic group. There was no significant difference in age and gender distribution between the two groups (both P>0.05). Western blotting analysis showed that the expression levels of NLRP3, caspase-1 and GSDMD protein in the LECs of anterior capsule were 1.11±0.06, 0.95±0.04 and 0.39±0.03 in the diabetic group, significantly higher than those of the non-diabetic group (0.81±0.04, 0.33±0.11 and 0.16±0.04; t=4.38, 5.36, 4.63; all P<0.05). Real-time quantitative PCR showed that the levels of NLRP3, caspase-1 and GSDMD mRNA in the LECs of anterior capsule were 1.98±0.07, 54.36±4.88 and 6.98±1.18 in the diabetic group, significantly higher than those of the non-diabetic group (1.38±0.16, 15.31±1.51 and 2.41±0.95; t=3.49, 7.64, 3.00, all P<0.05). Immunohistochemical staining showed that the average gray values of NLRP3, caspase-1 and GSDMD in the diabetic group were higher than those of the non-diabetic group (all P˂0.01). ELISA showed that the levels of IL-1β and IL-18 in the aqueous humor were (4.178±0.028) fg/L and (20.983±0.018) fg/L in the diabetic group, significantly higher than those of the non-diabetic group [(4.063±0.017) fg/L and (20.509±0.073) fg/L; t=20.63, 37.21; both P˂0.01]. Conclusion: Caspase-1-mediated pyroptosis of LECs and the release of inflammatory mediators induced by pyroptosis may be involved in the occurrence and development of diabetic cataract.

[HCV and Treponema pallidum infection status in HIV/AIDS cases in Yunnan province, January-June, 2020]

Objective: To understand the infection status of HCV and Treponema pallidum (TP) in HIV/AIDS cases in Yunnan province,and identify the risk factors. Methods: Between January 1 and June 30 in 2020,a cross-sectional survey was conducted in Yunnan. Two enzyme-linked immunosorbent assay (ELISA) kits were used to detect anti-HCV, the positive results of both two kits indicated HCV infection. ELISA and syphilis toluidine red untreated serum test were applied to identify TP infection. Both Excel 2016 and SPSS 22.0 software were used for statistical analysis, and logistic regression model was conducted to identify the relevant factors of HCV and TP infection. Results: A total of 5 922 HIV/AIDS cases were included in this study, the infection rates of HCV and TP were 6.5% (383/5 922) and 5.8% (344/5 922) respectively. The co-infection rate of HCV and TP was 0.4% (22/5 922). The risk for HCV infection in HIV/AIDS cases was higher in younger age groups compared with age group ≥50 years (15-19:aOR=3.53;20-29:aOR=3.02;30-39:aOR=2.91;40-49:aOR=3.61), in males than in females (aOR=2.31), in the married and unmarried than in the divorced or widowed (married:aOR=1.61;unmarried:aOR=1.63), in other ethnic groups than in Han ethnic group (aOR=1.70), in people with lower education level than in people with education level of college and above (primary school degree and below:aOR=4.69;middle school:aOR=3.96), in people living in the central and western Yunnan than in people living in eastern Yunnan (central Yunnan:aOR=2.46; western Yunnan:aOR=7.08), in injection drug users than in MSM (aOR=131.08). The risk of TP infection in HIV/AIDS cases was higher in people with education level of college and primary school than in middle school degree (primary school and below:aOR=1.73;college and above:aOR=1.77), in people with other occupations than in farmers (aOR=1.39), in people living in eastern Yunnan than in people living in western Yunnan (aOR=1.75); in MSM than in people with heterosex (aOR=9.75). Conclusions: A certain proportion of HIV/AIDS cases reported between January and June in 2020 in Yunnan were co-infected with HCV and TP, many factors were associated with the co-infection. It is suggested to strengthen HCV and TP tests in HIV/AIDS cases and conduct active treatment of the co-infection.

[The observation of secretogranin Ⅲ in the peripheral blood and vitreous of patients with diabetic retinopathy]

Objective: To study the expression levels of secretogranin Ⅲ (SCG3) in the peripheral blood and vitreous of patients with diabetic retinopathy (DR). Methods: Cross-sectional research. A total of 77 patients (41 men and 36 women, 77 eyes) received vitrectomy in Tianjin Medical University Eye Hospital from May to December 2018, with an average age of (60.75±11.34) years. According to the blood glucose level, diabetes history and fundus status, all the patients were divided into the DR group and the non-diabetic group. According to the patients' blood lipids and body mass index (BMI), patients were further divided into subgroups of high blood lipids, normal blood lipids, high BMI and normal BMI. All patients were tested with eye examinations, height and weight to calculate the BMI, and blood lipid levels in the peripheral blood. The vitreous was collected during the vitrectomy surgery, and the levels of SCG3 in the vitreous and peripheral blood were analyzed by ELISA. All the data were analyzed statistically with Wilcoxon rank sum test. Results: There were 43 patients in the DR group, among whom 25 had hyperlipidemia, 18 had normal blood lipids, 22 had a high BMI, and 21 had a normal BMI. There were 34 patients in the non-diabetic group, among whom 13 had hyperlipidemia, 21 had normal blood lipids, 17 had a high BMI, and 17 had a normal BMI. The level of SCG3 in the DR group [6.02 (4.34, 11.76) ng/ml] was higher than that in the non-diabetic group [4.30 (3.20, 10.78) ng/ml] (Z=-2.339, P =0.019). The level of SCG3 in the hyperlipidemia subgroup of the DR patients [7.94 (5.33, 13.51) ng/ml] was higher than that in the normal blood lipid subgroup of the non-diabetic patients [4.04 (3.12, 7.77) ng/ml] (Z=-3.473, P=0.001), and higher than that in the DR patients without hyperlipidemia [4.45 (3.71, 9.14) ng/ml] (Z=-2.511, P=0.012). The level of SCG3 in the DR patients with a high BMI [7.12 (4.56, 13.12) ng/ml] was higher than that in the non-diabetic patients with a normal BMI [3.53 (3.16, 4.38) ng/ml] (Z=-3.767, P =0.000). The level of SCG3 in the DR patients with a normal BMI [5.72 (4.10, 11.60) ng/ml] was higher than that in the non-diabetic patients with a normal BMI (Z=-2.862, P = 0.004). SCG3 in the plasma was rare or can not be detected. Conclusions: The concentration of SCG3 in the vitreous increase in DR patients. However, SCG3 can not be detected in the healthy vascular system. (Chin J Ophthalmol, 2020, 56: 933-937).

[Characteristics of HIV-1 genotype and drug resistance among men who have sex with men in Kunming, 2018]

Objective: To understand the characteristics of HIV-1 genotypes and drug resistance among men who have sex with men in Kunming in 2018. Methods: A total of 193 plasma samples were collected from the newly reported HIV-1 infected MSM in Kunming from January to December 2018. Viral RNA was extracted, and the gag, pol, env gene segments were amplified by nested PCR. HIV-1 genotypes and drug resistance were also analyzed. Subsequently, the evolutionary characteristics of CRF55_01B and CRF68_01B among MSM in Kunming were analyzed by Bayesian Markov Chain Monte Carlo method. Results: Multiple HIV-1 genotypes were identified among these 193 samples, including CRF07_BC (39.4%, 76/193), CRF01_AE (34.2%, 66/193), unique recombinant forms (URFs) (20.2%, 39/193), CRF08_BC (3.1%, 6/193), CRF55_01B (1.6%, 3/193), subtype B (1.0%, 2/193) and CRF68_01B (0.5%, 1/193). Results from the Bayesian evolutionary analysis showed that CRF55_01B started to spread locally after being imported from other provinces, while CRF68_01B was likely to have been brought in from the eastern provinces of China. Prevalence of HIV-1 drug resistant strains was 2.6%(5/190) before antiviral treatment, with mutation rates resistant to non-nucleoside reverse transcriptase inhibitors being the highest (2.1%, 4/190) among MSM in Kunming, 2018. Conclusion: The diversity of HIV-1 was increasing among MSM in Kunming. Although the resistance rate on pretreatment drug was relatively low, the emergence of multiple resistant strains to first-line antiviral drugs posed a challenge to antiretroviral therapy, in Kunming.

[Analysis on characteristics of HIV-1 molecular networks in men who have sex with men in Kunming, 2016-2018]

Objective: To analyze the characteristics of HIV-1 molecular network in men who have sex with men (MSM) from 2016 to 2018 in Kunming, Yunnan province, explore the risk factors associated with HIV-1 transmission network and provide evidence for the effective implementation of intervention. Methods: A total of 540 samples of newly reported HIV-1 positive MSM were consecutively collected in Kunming from 2016 to 2018, the pol gene fragments were amplified by nested polymerase chain reaction (PCR). HIV-1 molecular networks were constructed according to the bootstrap value of the maximum likelihood evolutionary tree over 95% and the genetic distance less than 3%. The factors associated with the subjects entering network and network growth were further analyzed. Results: Among 459 successfully sequenced samples, seven genotypes were found, in which CRF07_BC (49.2%, 226/459) and CRF01_AE (40.3%, 185/459 ) were predominant. Other genotypes included URFs (4.8%, 22/459), CRF08_BC (3.1%, 14/459), CRF55_01B (1.7%, 8/459), B (0.7%, 3/459) and CRF68_01B (0.2%, 1/459). A total of 163 sequences entered the network, with an entry rate of 35.5%(163/459), forming 56 clusters with the number of individuals in the cluster was between 2 and 13. The analysis of the factors associated with entering network showed that the MSM who married and had multiple homosexual partners were more likely to be found in HIV-1 molecular networks. Multivariate logistic regression analysis showed that the number of sexual partners was the factor for the growth of HIV-1 molecular network. According to the criteria for the emergence of three or more newly reported cases in every year, six transmission clusters were judged as active transmission clusters, in which MSM who were not Kunming natives, had sexually transmitted diseases (STD), were divorced and students were the key targets of intervention. Conclusions: HIV-1 genotypes in MSM in Kunming were becoming complex, the risk factors associated with transmission networks in MSM in Kunming included being married and having multiple partners, the intervention targets in active transmission clusters included MSM who were not Kunming natives, had STD, were divorced and students. This study provided the basis for applying HIV-1 molecular networks to real-time intervention in this population.

[Proteomic analysis of aqueous humor in acute primary angle-closure glaucoma]

Objective: To analyze the difference among expression of aqueous humor proteins in acute primary angle-closure glaucoma (APACG). Methods: Case-control study. The patients with APACG combined cataract (APACG with cataract group) and patients with cataract (cataract group), who had undertaken surgical treatment at the Tianjin Medical University Eye Hospital from October 2016 to June2017 were collected. Upon receipt of patient's consent, 50 μl of aqueous humor were collected with 1 ml syringe and No.1 needle through the surgical access during the surgery, and then injected into a sterile collection tube to be stored at -80 ℃. Those proteins extracted from aqueous humor were analyzed by quantitative proteomic mass spectrometry. The differential significance test was performed by Maxquant significances A approach. The differential proteins of the two groups were screened and determined with the conditions of P<0.05 and difference multiple>2. The functions and signal pathway of differential proteins in aqueous humor were annotated in biological big data, on the basis gene ontology (GO) and the Kyoto gene and genomic encyclopedia (KEGG) analyses. Results: There were 3 males and 7 females with an average age of (68±6) years in the APACG group. The cataract group included 2 males and 8 females with an average age of (71±8) years. There were no statistical differences in gender ratio and age between the two groups (both P>0.05). A total of 91 differential proteins were detected in this experiment, including 50 up-regulated proteins (annexinA1, vimentin, S100 calcium binding protein A8, interleukin 6, C reactive protein, laminin β2, etc.) and 41 down-regulated (keratin 85, γ-crystallin D, syntaxin-binding protein 5, semaphoring 4B, matrilin 2, cathepsin O, cadherin 4, semaphoring 3B, platelet-derived growth factor D, transforming growth factor β, etc.). On one hand, the functions of differential proteins involved in many aspects. AnnexinA1, CD163, S100 calcium-binding protein A8, C reactive protein, interleukin 6 are involved in the inflammatory reaction, cadherin 4 and laminin β2 regulate cell adhesion, matrilin 2, vimentin and laminin β2 participate in tissue fibrosis; on the other hand, KEGG analysis showed that the differential proteins participate diverse signaling pathways such as phosphatidylinositol-3-kinase-protein kinase B signaling pathway, transformation growth factor β signaling pathway, mitogen activated protein kinase signaling pathway, Toll-like receptor signaling pathway, the nuclear factor κ-light chain enhancer of the activated B cells signaling pathway, focal adhension and extracellular matrix receptor interaction pathway and so on. Conclusions: The expression of annexin A1 is significantly up-regulated in the aqueous humor in APACG, while some other factors such as transformation growth factor β, cadherin-4, and matrilin 2 are down-regulated. The change of proteins in aqueous humor is related with the outbreak of APACG. (Chin J Ophthalmol, 2019, 55: 687-694).

[Effects of SMP-30 overexpression on apoptosis of human lens epithelial cells induced by ultraviolet B irradiation]

Objective: This study was to observe the effect of SMP-30 on ultraviolet B (UVB)-induced apoptosis of human lens epithelial cells(HLE-B3) in vitro. Methods: Experimental study. The SMP-30 cDNA was amplified by PCR and inserted into the pRFP-N1 expressing vector which had been double digested by XhoI/HindIII. HLE-B3 cells were cultured and divided into three groups: normal group, pRFP-N1 vector plasmid group and pRFP-N1-SMP-30 plasmid group (SMP-30). Then cells were exposed to UVB and the survival rate of cells was detected by MTT assay. The effects of SMP-30 on UVB-induced HLE-B3 apoptosis were measured by the Cell Death Detection ELISA kit. Meanwhile, the influence of SMP-30 on UVB-induced apoptosis-relative protein expression in HLE-B3 cells was tested by Western blots. Moreover, 2', 7'-Dichlorofluorescin diacetate staining was performed to monitor the protective effects of SMP-30 on UVB-induced HLE-B3 reactive oxygen species(ROS). One-way analysis of variance combined with Dunnett's statistical method were performed to analyze the data. Results: The full length of PSF cDNA fragment was correctly inserted into the pRFP-N1 vector, which was confirmed by DNA sequencing. The SMP-30 fragment was inserted to the plasmid pRFP-N1 correctly, which was also confirmed by DNA sequencing. The PRFP-N1-SMP-30 plasmid was transfected into HLE-B3 successfully. SMP-30 expression was up-regulated in the transfection group, compared with the control group. Data showed that the survival rate of HLE-B3 after the pRFP-N1-SMP-30 plasmid transfection was 0.90±0.14, while the apoptosis rate was 0.43±0.06 and the ROS production was 0.52±0.02, showing significant difference in comparison with the vector plasmid group and the normal group(t=5.830, 9.934, 12.19, P<0.05). In the meantime, SMP-30 overexpression down-regulated the levels of Bax and cleav-caspase-3, but up-regulated the Bcl-2 and Pro-caspase-3 expression levels under UVB irradiation. Conclusion: SMP-30 overexpression plays a protective role in UVB-induced apoptosis via regulating the expression of apoptosis-related proteins and inhibiting the production of ROS in HLE-B3 cells. (Chin J Ophthalmol, 2017, 53: 835-841).

[Chimeric antigen receptors T cells for treatment of 48 relapsed or refractory acute lymphoblastic leukemia children: long term follow-up outcomes]

Objective: To evaluate the safety and efficacy of chimeric antigen receptors T cells (CAR-T) in childhood acute B lymphoblastic leukemia (B-ALL) to probe the prognosis-related factors. Methods: Forty-eight children, 29 boys and 19 girls, aged 3-17years old (median age was 8 years old) , with recurrent or refractory CD19 positive B-ALL, were treated by the CD19 specific CAR-T cells. A total of 48 cases received 61 infusions. Flow cytometry or real-time quantitative polymerase chain reaction method were used to monitor micro residual disease (MRD) . The follow-up period was from 16 to 1 259 days with the median follow-up of 406 days. SPSS software was used to statistical analysis. Results: No adverse reaction was observed during 61 infusions. The most common adverse reaction after CAR-T cell infusions was cytokine-release syndrome (CRS) . Only 2 cases experienced level 3 CRS performance, including continuous high fever, convulsions, delirium, serous cavity effusion, and decreasing of blood pressure. Tocilizumab was given to release CRS performance. No treatment-related death occurred. Thirty-seven patients showed response during 7 to 28 days after infusions. The early response rate was 77.1%, with MRD before infusion less than 5% group higher than the MRD more than 5% group (87.1% vs 58.8%, χ2=4.968, P=0.036) . For the 37 patients who showed response to CAR-T cell infusions, univariate analysis identified that age, disease status at the time of treatment, MRD before infusion affected 2-year OS rate (P<0.05) . Multivariate prognostic analysis for EFS disclosed that the MRD before infusion more than 5% (RR=3.433, 95% CI 1.333-8.844, P=0.011) and not bridge to HSCT (RR=4.996, 95% CI 1.852-13.474, P=0.001) were the independent risk factors. Conclusion: The fourth generation CAR-T cells directed against CD19 could effectively and safely treat relapsed and refractory B-ALL, which implicated that CAR-T therapy as a novel therapeutic approach could be useful for patients with relapsed or refractory B-ALL who have failed all other treatment options. Reducing MRD as far as possible by effective pretreatment chemotherapy was in favor of increasing the response rate. Bridging HSCT after CAR-T cell treatment might be a better therapeutic strategy for the patient with refractory or molecular relapsed B-ALL.

[An analysis of various diseases and hearing screening in NICU infants]

Objective:It is the first time to study the hearing screening results in NICU infants in Heilongjiang province,to analyze the various diseases and hearing loss distribution in NICU infants.Method:Three hundred and thirty four newborns(668 ears) in NICU received hearing screening with TEOAE and AABR test.We compared the results of different risk factors.Result:The failed ratio of different diseases in NICU are as follow: premature infants 61%,hypoxic-ischemic encephalopathy(HIE) 35%,neonatal infectious pneumonia 30%,neonatal sepsis 30%,neonatal aspiration pneumonitis 36%,neonatal jaundice 29%.Conclusion:The positive ratio of preterm infants was 61%,which is higher than the other diseases in NICU infants of Heilongjiang province.Both TEOAE and AABR failure have a high incidence of abnormal hearing status.Neonatal jaundice,neonatal infectious pneumonia and premature infants diseases are the high risk factors of auditory neuropathy spectrum disorder(ANSD) in NICU infants of Heilongjiang.

[Expression of signaling pathway of mammalian target of rapamycin in articular cartilage cell induced by interleukin 1β]

Objective: To observe effect of interleukin(IL)-1β on the expression of signaling pathway of mammalian target of rapamycin(mTOR) of articular cartilage. Methods: Articular cartilage of rats was isolated under sterile technique, cells were digested by type Ⅱ collagenase and trypsin and cultured in vitro, pre-culture the Ⅱ cells for three days, different concentrations of IL-1β were added for 24 hours.The cells were stained with toluidine blue and HE, to observe morphological changes of cells.RT-PCR was used to detect the mRNA expression of typeⅡcollagen gene, aggrecan gene, mTOR gene and P70S6K gene, Western blotting was used to detect the expression of protein related to mTOR. Results: With increasing concentrations of IL-1β, the phenotype of cells appeared polygon into a spindle, the mRNA expression of gene of type Ⅱ collagen (the control group: 0.821±0.014; 1 ng/ml: 0.614±0.014; 10 ng/ml: 0.549±0.009; 100 ng/ml: 0.520±0.008), aggrecan(0.867±0.005; 0.857±0.001; 0.554±0.008; 0.538±0.004) and mTOR(0.845±0.015; 0.785±0.009; 0.569±0.025; 0.518±0.014) reduced, but P70S6K(0.465±0.024; 0.566±0.022; 0.663±0.022; 0.896±0.015) increased by PCR .Expression of protein detected by Western blotting was similar to the trend of PCR. Conclusion: mTOR signaling pathway may play an important role on the degeneration of articular cartilage, regulating mTOR signaling pathway may provides a new idea of delaying the degeneration process of cells.

Microdetermination of proteins with the arsenazo-DBN-Al(III) complex by Rayleigh light-scattering technique and application of the method

The determination of proteins with arsenazo-DBN and Al3+ by Rayleigh light-scattering (RLS) is described. The weak RLS of arsenazo-DBN and BSA can be enhanced greatly by addition of Al3+ in the pH range 5.3-7.0; this resulted in two enhanced RLS signals at 420-440 nm and 460-480 nm. The reaction between arsenazo-DBN, Al3+, and proteins was studied and a new method was developed for quantitative determination of proteins. This method is very sensitive (0.34-41.71 microg mL(-1) for bovine serum albumin, BSA, and 0.29-53.41 microg mL(-1) for human serum albumin, HSA), rapid (< 2 min), simple (one step), and tolerant of most interfering substances. The effects of different surfactants were also examined. When these proteins were determined in four human serum samples the maximum relative error was not more than 2% and the recovery was between 97 and 103%.

Bile salts: natural detergents for the prevention of sexually transmitted diseases

The development of new, safe, topical microbicides for intravaginal use for the prevention of sexually transmitted diseases is imperative. Previous studies have suggested that bile salts may inhibit human immunodeficiency virus infection; however, their activities against other sexually transmitted pathogens have not been reported. To further explore the potential role of bile salts in preventing sexually transmitted diseases, we examined the in vitro activities and cytotoxicities of select bile salts against Chlamydia trachomatis, herpes simplex virus (types 1 and 2), Neisseria gonorrhoeae, and human immunodeficiency virus in comparison to those of nonoxynol-9 and benzalkonium chloride using both primary cells and cell lines derived from the human female genital tract. We found that taurolithocholic acid 3-sulfate and a combination of glycocholic acid and taurolithocholic acid 3-sulfate showed excellent activity against all of the pathogens assayed. Moreover, taurolithocholic acid 3-sulfate alone or in combination was less cytotoxic than nonoxynol-9 and benzalkonium chloride. Thus, taurolithocholic acid 3-sulfate alone or in combination warrants further evaluation as a candidate topical microbicidal agent.

Catalytic subunit of DNA-dependent protein kinase: impact on lymphocyte development and tumorigenesis

The DNA-dependent protein kinase (DNA-PK) consists of a heterodimer DNA-binding complex, Ku70 and Ku80, and a large catalytic subunit, DNA-PKcs. To examine the role of DNA-PKcs in lymphocyte development, radiation sensitivity, and tumorigenesis, we disrupted the mouse DNA-PKcs by homologous recombination. DNA-PKcs-null mice exhibit neither growth retardation nor a high frequency of T cell lymphoma development, but show severe immunodeficiency and radiation hypersensitivity. In contrast to the Ku70-/- and Ku80-/- phenotype, DNA-PKcs-null mice are blocked for V(D)J coding but not for signal-end joint formation. Furthermore, inactivation of DNA-PKcs leads to hyperplasia and dysplasia of the intestinal mucosa and production of aberrant crypt foci, suggesting a novel role of DNA-PKcs in tumor suppression.

Domain-specific interactions between entactin and neutrophil integrins. G2 domain ligation of integrin alpha3beta1 and E domain ligation of the leukocyte response integrin signal for different responses

Extracellular matrix proteins activate neutrophils to up-regulate many physiologic functions that are necessary at sites of tissue injury. To elucidate the ligand-receptor interactions that mediate these functions, we examined neutrophil activation by the basement membrane protein, entactin. Entactin is structurally and functionally organized into distinct domains; therefore, we utilized glutathione S-transferase -fusion proteins encompassing its four major domains, G1, G2, E, and G3, to assess interactions between entactin and neutrophil integrin receptors. We show that the E domain, which contains the single RGD sequence of entactin, is sufficient for ligation of the beta3-like integrin, leukocyte response integrin, and signaling for chemotaxis. Moreover, the G2 domain signals for stimulation of Fc receptor-mediated phagocytosis via ligation of alpha3beta1. This receptor-ligand interaction was revealed only after stimulation of neutrophil by immune complexes or phorbol esters. Interestingly, the E domain does not enhance phagocytosis, and the G2 domain is not chemotactic. Furthermore, cleavage of entactin with the matrix metalloproteinase, matrilysin, liberates peptides that retain E domain-mediated chemotaxis and G2 domain-mediated enhancement of phagocytosis. These studies indicate that multiple domains of entactin have the ability to ligate individual integrins expressed by neutrophils and to activate distinct functions.

Two distinct cell attachment sites in entactin are revealed by amino acid substitutions and deletion of the RGD sequence in the cysteine-rich epidermal growth factor repeat 2

The basement membrane glycoprotein, entactin, has previously been shown to promote cell attachment and chemotaxis. We have constructed a panel of glutathione S-transferase fusion proteins that encompasses the four major structural domains of entactin, G1, G2, E, and G3. These proteins have been synthesized in bacteria and purified by affinity chromatography. The connecting stalk of entactin, E, which contains four cysteine-rich EGF homology repeats and the integrin receptor RGD recognition sequence, has been modified by deletion of the RGD sequence and substituting glutamic acid for aspartic acid. Attachment assays reveal that the RGD sequence is one of the major cell attachment sites in entactin and that this sequence is recognized by the alpha v beta 3 integrin receptor. Analysis of cell attachment on mutant forms of full-length entactin expressed in the baculovirus expression system revealed a second attachment site that was independent of the RGD sequence. This second site was localized to a peptide of 39 amino acid residues in the second globular G2 domain of entactin. This peptide represents a cysteine-rich EGF repeat. Inhibition of cell attachment by anti-integrin receptor antibodies indicates that the second attachment site is recognized by a member of the beta 1 family of integrin receptors, possibly alpha 3 beta 1.

Recombinant entactin promotes mouse primary trophoblast cell adhesion and migration through the Arg-Gly-Asp (RGD) recognition sequence

In vitro culture of mouse blastocysts during the period coinciding with implantation has revealed that primary trophoblast cells can adhere and migrate in serum-free medium when provided with certain extracellular matrix components, including fibronectin and laminin. Tightly associated with laminin is the glycoprotein, entactin, that may play an important role in basement membrane assembly and cell attachment. Mouse blastocysts were studied using this in vitro model to determine whether entactin was capable of mediating trophoblast invasive activity. Although entactin has never been shown to promote cell migration, we report here that recombinant entactin supported blastocyst outgrowth in a dose-dependent manner, with a maximal effect at 20-50 micrograms/ml. The ability of trophoblast cells to adhere and migrate on entactin was specifically inhibited by anti-entactin antibody, but not by antibodies raised against laminin. The synthetic peptide, Gly-Arg-Gly-Asp-Ser-Pro, that contains the Arg-Gly-Asp (RGD) integrin recognition site, reversibly inhibited entactin-mediated blastocyst outgrowth in a dose-dependent manner, but had no effect on laminin-mediated outgrowth. The synthetic peptide, Gly-Phe-Arg-Gly-Asp-Gly-Gln, that comprises the actual RGD-containing sequence within entactin, promoted trophoblast outgrowth when immobilized on the substratum. Furthermore, a mutated recombinant entactin, altered to contain a Glu in place of Asp at the RGD site, provided no trophoblast cell adhesive activity. We conclude that entactin promotes trophoblast outgrowth through a mechanism mediated by the RGD recognition site, and that it may play an important role during invasion of the endometrial basement membrane at implantation.

Biological functions of entactin

Entactin is a sulfated multidomain glycoprotein component of basement membranes. The molecule consists of 1217 amino acids which are organized into two terminal globular domains linked by a rod-like structure largely composed of four EGF- and one thyroglobulin-like cysteine-rich homology repeats. Entactin binds to laminin, collagen IV, fibrinogen, and fibronectin. In the parietal endoderm M1536-B3 cell line, the laminin-entactin complex is formed intracellularly and transported in membrane enclosed vesicles to the extracellular compartment. Transfection of human choriocarcinoma JAR cells, which do not synthesize entactin, with entactin cDNA results in the synthesis and insertion of entactin into the extracellular matrix where it becomes associated with laminin and collagen IV. Indirect immunofluorescent staining also reveals that entactin co-localizes with fibronectin in the extracellular matrix of the embryonal carcinoma-derived 4CQ cell line. These observations suggest that entactin plays an important role in the assembly and properties of diverse extracellular matrices. In addition, entactin binds to immobilized fibrinogen, and more specifically, to the A alpha and B beta chains. The binding of radiolabeled entactin to immobilized fibrinogen is not dependent on metal ions, and is inhibited by antibodies against either fibrinogen or entactin, soluble fibrinogen, and unlabeled entactin. This interaction combined with the chemotactic and phagocytic promoting activities of entactin may be important in hemostasis and would healing.

The expression of the genes for entactin, laminin A, laminin B1 and laminin B2 in murine lens morphogenesis and eye development

The temporal expression of the genes for the excellular matrix proteins entactin and the A, B1, and B2 chains of laminin was examined in the eye of the developing mouse embryo by in situ hybridization of their messenger RNAs. Entactin messenger RNA was found in abundance in specific cells. In the 25 somite embryo entactin message was synthesized by mesenchymal cells and, at later stages, by hyalocytes and lens cells in addition. The message was not detectable in corneal epithelium at embryonic stages E15 and E18.5 and at birth but was present in adjacent stromal cells. At the 28 and 38 somite stages, before pigment granules interfered with the detection of silver grains, no entactin message was detected in pigmented epithelial cells, in contrast to the messages for laminin B1 and B2. Entactin was not found in the neural epithelium at any time during development. The distribution of the laminin B1, B2 and A chain messenger RNAs was distinctly different from that of entactin. In particular, during the early stages of development B1 and B2 messages were synthesized by ectodermal, lens, corneal, pigment epithelial and hyaloid cells. In the older embryos cells in the ganglion layer of the retina synthesized B1 and B2 messages but undetectable amounts of entactin or the A chain messages. In general the A chain message was in lower abundance throughout development. The distribution of laminin and entactin messages suggested that the extracellular matrices, which contained both proteins, can be derived either from a single cell type or from the contributions of multiple cell types. The data demonstrate the complexity of extracellular matrix synthesis and assembly in the diverse structures of the developing eye where the temporal expression of specific molecules are tailored to the specific developmental requirements of particular structures.

Characterization of the basement membrane glycoprotein entactin synthesized in a baculovirus expression system

A cDNA clone encoding the entire open reading frame of mouse entactin was constructed. This cDNA was inserted into Autographa californica multiple nuclear polyhedrosis virus and expressed in Spodoptera frugiperda, Sf9, insect cells. The recombinant entactin was produced in large quantities under the control of the polyhedrin promoter. Amino terminus sequence analysis indicated that the signal peptide in the preprotein was correctly cleaved. Polyclonal antibodies prepared against either the naturally occurring or recombinant entactin cross-reacted with both molecules in the native and denatured states. The recombinant molecule promoted cell attachment and exhibited a calcium- and temperature-dependent self-aggregation. These properties reflect those of the naturally occurring mouse molecule. Although entactin is an extracellular matrix component that is normally exocytosed, the vast majority of the molecules were localized inside the cell by immunoelectron microscopy where the molecules formed insoluble aggregates.