Altered Cell Clusters and Upregulated Aqp1 in Connexin 50 Knockout Lens Epithelium.

Purpose: To characterize the heterogeneity and cell clusters of postnatal lens epithelial cells (LECs) and to investigate the downstream targets of connexin 50 (Cx50) in the regulation of lens homeostasis and lens growth. To determine differentially expressed genes (DEGs) in the connexin 50 knockout (Cx50KO) lens epithelial cells that shed light on novel mechanism underlying the cataract and small size of the Cx50KO lenses. Methods: Single-cell RNA sequencing (scRNA-seq) of lens epithelial cells isolated from one-month-old Cx50KO and wild-type (WT) mice were performed. Differentially expressed genes were identified, and selected DEGs were further studied by quantitative real-time PCR (RT-qPCR) analysis and Western blot analysis. Results: The expression profiles of several thousand genes were identified by scRNA-seq data analysis. In comparison to the WT control, many DEGs were identified in the Cx50KO lens epithelial cells, including growth regulating transcriptional factors and genes encoding water channels. Significantly upregulated aquaporin 1 (Aqp1) gene expression was confirmed by RT-qPCR, and upregulated AQP1 protein expression was confirmed by Western blot analysis and immunostaining both in vivo and in vitro. Conclusions: Lens epithelial cells exhibit an intrinsic heterogeneity of different cell clusters in regulating lens homeostasis and lens growth. Upregulated Aqp1 in Cx50KO lens epithelial cells suggests that both connexin 50 and AQP1 likely play important roles in regulating water homeostasis in lens epithelial cells.

Research Competence in Clinical Nursing Insights From Chinese Nurses: A Cross-Sectional Survey.

AIM: To assess the research capacity of 3014 clinical nurses in northeastern China, examining their participation in research and self-assessed competencies to advance nursing practice. BACKGROUND: Nursing research is essential for the development of the nursing discipline, yet significant progress in enhancing the research capabilities of nursing staff has been limited over the past decades. Clinical nurses, central to the execution of research activities, need improved research skills to identify relevant topics and synthesise clinical experiences with the literature. DESIGN: A cross-sectional survey. METHODS: In 2023, using a convenience sampling method, a cross-sectional questionnaire survey was conducted on 3014 nurses in a Grade A tertiary hospital. The questionnaire included questions on basic information and scientific research, as well as a self-evaluation scale assessing the nurses' capability for conducting scientific research. RESULTS: Among the nurses participating in the survey, 29.66% (894) had published academic papers in Chinese, 2.06% (62) had published papers in Science Citation Index journals, 2.39% (72) had hosted nursing research projects, 5.87% (177) had participated in nursing research projects and 71% (2140) expressed their willingness to participate in nursing research activities. The average score on the self-evaluation of research capability was 54.08 ± 24.55, with scores ranging from 0 to 120. CONCLUSION: The clinical nurses' research capacity scores are at the midpoint of the scale (0-120), indicating basic research capabilities with room for improvement. There is a high willingness to engage in research. Nursing managers should consider these factors in training programmes and promote research activities to improve the team's scientific capability. RELEVANCE TO CLINICAL PRACTICE: This study reveals a critical gap between nurses' willingness and actual involvement in research, emphasising the need for enhanced research skills to improve nursing practice. PATIENT OR PUBLIC CONTRIBUTION: This study did not require patient or public involvement in its design, outcome measures or execution. The contribution of patients/members of the public was limited solely to data collection.

Design, Synthesis, in Vitro and in Vivo Biological Evaluation of Pterostilbene Derivatives for the Treatment of Inflammatory Bowel Disease.

The aberrant activation of NLRP3 inflammasomes is intricately linked to various inflammatory diseases. In this study, we present the discovery and optimization of a series of NLRP3 inflammasome inhibitors based on the pterostilbene skeleton. All compounds underwent screening to evaluate their inhibitory effects on LPS/Nigericin-induced IL-1ß secretion and anti-cellular pyroptosis. Most compounds exhibit good biological activity and cellular safety, with compound D20 showing the most prominent activity. Preliminary mechanism studies suggest that compound D20 may affect the assembly of NLRP3 inflammasomes by targeting the NLRP3 protein, thereby inhibiting the activation of NLRP3 inflammasomes. The in vivo anti-inflammatory activity demonstrated significant therapeutic effect of compound D20 on DSS-induced acute colitis model in mice. This work has important reference significance for the development of drugs targeting NLRP3 inflammasomes.

PLCγ1 deficiency in chondrocytes accelerates the age-related changes in articular cartilage and subchondral bone.

Ageing is the most prominent risk for osteoarthritis (OA) development. This study aimed to investigate the role of phosphoinositide-specific phospholipase Cγ (PLCγ) 1, previously linked to OA progression, in regulating age-related changes in articular cartilage and subchondral bone. d-galactose (d-Gal) was employed to treat chondrocytes from rats and mice or injected intraperitoneally into C57BL/6 mice. RTCA, qPCR, Western blot and immunohistochemistry assays were used to evaluate cell proliferation, matrix synthesis, senescence genes and senescence-associated secretory phenotype, along with PLCγ1 expression. Subchondral bone morphology was assessed through micro-CT. In mice with chondrocyte-specific Plcg1 deficiency (Plcg1flox/flox; Col2a1-CreERT), articular cartilage and subchondral bone were examined over different survival periods. Our results showed that d-Gal induced chondrocyte senescence, expedited articular cartilage ageing and caused subchondral bone abnormalities. In d-Gal-induced chondrocytes, diminished PLCγ1 expression was observed, and its further inhibition by U73122 exacerbated chondrocyte senescence. Plcg1flox/flox; Col2a1-CreERT mice exhibited more pronounced age-related changes in articular cartilage and subchondral bone compared to Plcg1flox/flox mice. Therefore, not only does d-Gal induce senescence in chondrocytes and age-related changes in articular cartilage and subchondral bone, as well as diminished PLCγ1 expression, but PLCγ1 deficiency in chondrocytes may also accelerate age-related changes in articular cartilage and subchondral bone. PLCγ1 may be a promising therapeutic target for mitigating age-related changes in joint tissue.

Longitudinal study of microphthalmia in connexin 50 knockout mice using spectral-domain optical coherence tomography.

Connexin 50 (Cx50) mediated signaling is essential for controlling the lens growth and size. Cx50 mutations cause microphthalmia, smaller lenses, and cataracts in humans and animals. These ocular defects have never been investigated in live Cx50 mutant mice by using non-invasive imaging techniques. Here, we report a longitudinal study of the ocular defects in Cx50 knockout (Cx50KO) mice from the ages of 3 weeks to 12 months by using spectral-domain optical coherence tomography (SD-OCT). The anterior chamber depth (ACD), lens thickness (LT), vitreous chamber depth (VCD), and axial length (AL) were measured along the visual axis and adjusted with corresponding refractive indices. The SD-OCT image data confirm age-related reductions of LT and AL in live Cx50KO mice compared to age-matched wild-type (WT) controls, and the reduction values are comparable to the in vitro measurements of Cx50KO eyeballs and lenses reported previously. Moreover, reductions of ACD were observed in Cx50KO mice at all ages studied while VCD changes are statistically insignificant in comparison to the WT controls. Therefore, Cx50KO's microphthalmia with small lens is selectively associated with delayed ACD development but not the vitreous formation. This work supports the notion that lens size and/or growth is important for anterior chamber development.

Measurement of 224Ra in water via pulsed ionization chamber (PIC) radon detector.

224Ra (t1/2 = 3.6 d) has been widely used as a tracer in environmental water research. Here, we present a new method for measuring 224Ra in natural waters using a pulsed ionization chamber (PIC)-based radon detector. This method is based on the measurement of the 224Ra daughter isotope 220Rn (thoron) after reaching secular equilibrium within 7 min. Radium isotopes are concentrated on ''Mn-fibers'' before measurement of 220Rn, which can be distinguished from 222Rn by the difference in their half-lives. The measurement efficiency of the method is 0.20 ± 0.01 cps/Bq at an optimum airflow rate of 1.0 L/min and a water/Mn-fiber weight ratio of 1.0. Results from natural water samples obtained by this method agree well with analysis via RaDeCC, an established technique for 224Ra assessments. Since the PIC system is lighter compared to RaDeCC, easier to operate, and does not require the usage of helium carrier gas and desiccant, this method is recommended for in-situ 224Ra measurement in long-term fieldwork with limited logistical support.

Association between pretreatment emotional distress and immune checkpoint inhibitor response in non-small-cell lung cancer.

Emotional distress (ED), commonly characterized by symptoms of depression and/or anxiety, is prevalent in patients with cancer. Preclinical studies suggest that ED can impair antitumor immune responses, but few clinical studies have explored its relationship with response to immune checkpoint inhibitors (ICIs). Here we report results from cohort 1 of the prospective observational STRESS-LUNG study, which investigated the association between ED and clinical efficacy of first-line treatment of ICIs in patients with advanced non-small-cell lung cancer. ED was assessed by Patient Health Questionnaire-9 and Generalized Anxiety Disorder 7-item scale. The study included 227 patients with 111 (48.9%) exhibiting ED who presented depression (Patient Health Questionnaire-9 score ≥5) and/or anxiety (Generalized Anxiety Disorder 7-item score ≥5) symptoms at baseline. On the primary endpoint analysis, patients with baseline ED exhibited a significantly shorter median progression-free survival compared with those without ED (7.9 months versus 15.5 months, hazard ratio 1.73, 95% confidence interval 1.23 to 2.43, P = 0.002). On the secondary endpoint analysis, ED was associated with lower objective response rate (46.8% versus 62.1%, odds ratio 0.54, P = 0.022), reduced 2-year overall survival rate of 46.5% versus 64.9% (hazard ratio for death 1.82, 95% confidence interval 1.12 to 2.97, P = 0.016) and detriments in quality of life. The exploratory analysis indicated that the ED group showed elevated blood cortisol levels, which was associated with adverse survival outcomes. This study suggests that there is an association between ED and worse clinical outcomes in patients with advanced non-small-cell lung cancer treated with ICIs, highlighting the potential significance of addressing ED in cancer management. ClinicalTrials.gov registration: NCT05477979 .

Transcriptome analysis and functional verification reveal the roles of copper in resistance to potato virus Y infection in tobacco.

Potato virus Y (PVY) is one of the most important pathogens in the genus Potyvirus that seriously harms agricultural production. Copper (Cu), as a micronutrient, is closely related to plant immune response. In this study, we found that foliar application of Cu could inhibit PVY infection to some extent, especially at 7 days post inoculation (dpi). To explore the effect of Cu on PVY infection, transcriptome sequencing analysis was performed on PVY-infected tobacco with or without Cu application. Several key pathways regulated by Cu were identified, including plant-pathogen interaction, inorganic ion transport and metabolism, and photosynthesis. Moreover, the results of virus-induced gene silencing (VIGS) assays revealed that NbMLP423, NbPIP2, NbFd and NbEXPA played positive roles in resistance to PVY infection in Nicotiana benthamiana. In addition, transgenic tobacco plants overexpressing NtEXPA11 showed increased resistance to PVY infection. These results contribute to clarify the role and regulatory mechanism of Cu against PVY infection, and provide candidate genes for disease resistance breeding.

Gender, Sexism, and Police Attitudes Toward Policing Intimate Partner Violence in China.

This study examines the impact of gender and sexism on police officers' attitudes toward policing intimate partner violence (IPV). Data were collected from 826 Chinese police officers through online questionnaires. A hierarchical multiple regression analysis found that male police officers and those with sexist attitudes believe that handling IPV cases is illegitimate; they tend to perceive that the police are not morally bound to regulate such cases. Meanwhile, policewomen are less likely to consider that IPV interventions are difficult and resource-intensive. Findings indicate the need to amend policies and practices concerning gender and sexism among police officers to control IPV.

Accelerated 3D MR neurography of the brachial plexus using deep learning-constrained compressed sensing.

OBJECTIVES: To explore the use of deep learning-constrained compressed sensing (DLCS) in improving image quality and acquisition time for 3D MRI of the brachial plexus. METHODS: Fifty-four participants who underwent contrast-enhanced imaging and forty-one participants who underwent unenhanced imaging were included. Sensitivity encoding with an acceleration of 2 × 2 (SENSE4x), CS with an acceleration of 4 (CS4x), and DLCS with acceleration of 4 (DLCS4x) and 8 (DLCS8x) were used for MRI of the brachial plexus. Apparent signal-to-noise ratios (aSNRs), apparent contrast-to-noise ratios (aCNRs), and qualitative scores on a 4-point scale were evaluated and compared by ANOVA and the Friedman test. Interobserver agreement was evaluated by calculating the intraclass correlation coefficients. RESULTS: DLCS4x achieved higher aSNR and aCNR than SENSE4x, CS4x, and DLCS8x (all p < 0.05). For the root segment of the brachial plexus, no statistically significant differences in the qualitative scores were found among the four sequences. For the trunk segment, DLCS4x had higher scores than SENSE4x (p = 0.04) in the contrast-enhanced group and had higher scores than SENSE4x and DLCS8x in the unenhanced group (all p < 0.05). For the divisions, cords, and branches, DLCS4x had higher scores than SENSE4x, CS4x, and DLCS8x (all p ≤ 0.01). No overt difference was found among SENSE4x, CS4x, and DLCS8x in any segment of the brachial plexus (all p > 0.05). CONCLUSIONS: In three-dimensional MRI for the brachial plexus, DLCS4x can improve image quality compared with SENSE4x and CS4x, and DLCS8x can maintain the image quality compared to SENSE4x and CS4x. CLINICAL RELEVANCE STATEMENT: Deep learning-constrained compressed sensing can improve the image quality or accelerate acquisition of 3D MRI of the brachial plexus, which should be benefit in evaluating the brachial plexus and its branches in clinical practice. KEY POINTS: •Deep learning-constrained compressed sensing showed higher aSNR, aCNR, and qualitative scores for the brachial plexus than SENSE and CS at the same acceleration factor with similar scanning time. •Deep learning-constrained compressed sensing at acceleration factor of 8 had comparable aSNR, aCNR, and qualitative scores to SENSE4x and CS4x with approximately half the examination time. •Deep learning-constrained compressed sensing may be helpful in clinical practice for improving image quality and acquisition time in three-dimensional MRI of the brachial plexus.

Identification and Characterization of Retinitis Pigmentosa in a Novel Mouse Model Caused by PDE6B-T592I.

The cGMP-phosphodiesterase 6 beta subunit (PDE6B) is an essential component in the phototransduction pathway for light responses in photoreceptor cells. PDE6B gene mutations cause the death of rod photoreceptors, named as hereditary retinitis pigmentosa (RP) in humans and retinal degeneration (RD) in rodents. Here, we report a new RD model, identified from a phenotypic screen of N-ethyl-N-nitrosourea (ENU)-induced mutant mice, which displays retinal degeneration caused by a point mutation in the Pde6b gene that results in PDE6B-T592I mutant protein. The homozygous mutant mice show an extensive loss of rod photoreceptors at the age of 3 weeks; unexpectedly, the loss of rod photoreceptors can be partly rescued by dark rearing. Thus, this RD mutant model displays a light-dependent loss of rod photoreceptors. Both western blot and immunostaining results show very low level of mutant PDE6B-T592I protein in the retina. Structure modeling suggests that the T592I mutation probably affects the function and stability of PDE6B protein by changing intramolecular interactions. We further demonstrate that the expression of wild-type PDE6B delivered by subretinally injected adeno-associated virus (rAAV) prevents photoreceptor cell death in this RD model in vivo. The PDE6B-T592I mutant is, therefore, a valuable RD model for evaluating rAAV-mediated treatment and for investigating the molecular mechanism of light-dependent rod photoreceptor cell death that is related to impaired PDE6B function.

Getting Good Sleep with Family Support: The Role of Fear of Crime and Loneliness.

Sleep problems in middle-aged and older people can threaten their physical and mental health. Family support is regarded as a key factor that affects sleep quality, but the influence mechanism remains underexplored. This study analyzes the mediating effects of fear of crime (FOC) and loneliness in the relationship between family support and sleep quality, and explores whether gender plays a moderating role between family support and FOC. A questionnaire survey was conducted among 1043 Chinese middle-aged and older people aged 45-93 years. Using 10,000 bootstrapped samples, the study shows that middle-aged and older people who receive more family support have better sleep quality, and FOC and loneliness play mediating role in this association. Gender moderates the relationship between family support and FOC. Compared with men, family support for females has a greater impact on their FOC condition, and the mediating effect of family support on sleep quality through FOC is also greater among women. Family support can affect sleep quality through the chain mediating effect of FOC and loneliness for women. This study provides an in-depth understanding of the relationship between family support and sleep quality.

Impaired autophagy contributes to the aggravated deterioration of osteoarthritis articular cartilage by peroxisome proliferator-activated receptor α deficiency, associated with decreased ERK and Akt activation.

BACKGROUND: Although the chondroprotection of peroxisome proliferator-activated receptor α (PPARα) activation against osteoarthritis (OA) has been revealed, the regulatory mechanism of PPARα deficiency to aggravate osteoarthritic cartilage deterioration remains unclear. Here, we aimed to investigate whether and how autophagy is involved in OA pathological progression. METHODS: Model of experimental OA was established using destabilization of the medial meniscus in PPARα-KO 129S4/SvJae male mice, followed by histopathological detection of articular cartilage and immunohistochemistry detection of extracellular matrix (ECM) or autophagy-related signal molecules. Meanwhile, human OA chondrocytes obtained from total knee replacement surgery patients with OA were cultured with the pretreatment of IL-1ß, followed with the treatment of PPARα agonist WY14643 and the detection of related signal molecules. RESULTS: PPARα deficiency aggravated cartilage damage with decreased LC3B level in combination with an increase in P62 level, accompanied with reduced p-Akt and p-ERK levels in PPARα-KO mouse model of experimental OA. On the contrary, PPARα activation by WY14643 promoted ECM synthesis in IL-1ß-treated human OA chondrocytes, accompanied with increased LC3B-II/I ratio and Beclin 1 level and decreased P62 and Bcl2 levels. Meanwhile, it was observed that activated ERK and Akt by PPARα activation contributed to the enhancement of autophagy and ECM synthesis in human OA chondrocytes. CONCLUSIONS: Impaired autophagy contributed to the aggravated deterioration of osteoarthritis articular cartilage by PPARα deficiency associated with the suppression of ERK and Akt, with an implication that triggering PPARα activation ought to be a potential promising therapeutic target for OA therapy.

Alienation from medical care policy, medical care avoidance, and the role of sex and risk perception.

BACKGROUND: Medical care avoidance affects individuals' health status. Previous studies on medical care avoidance have mainly focused on medical costs and people's satisfaction with medical services. This study investigates whether an individual's sense of policy alienation toward medical care policy (SPA-M) affects behavioral intention of medical care avoidance, and to what extent an intermediary variable-medical financial risk perception-mediates the relationship between SPA-M and medical care avoidance. METHODS: A cross-sectional survey was conducted involving 434 people aged 35-59 years from Wuhu, a city in China's Anhui province. A moderated mediation model was constructed to investigate the research question and sex (biological: male and female) was used as a moderating variable between SPA-M and medical financial risk perception. RESULTS: We found that SPA-M significantly impacted medical care avoidance, and that medical financial risk perception played a complete mediating role in this relationship, while sex moderated the relationship between SPA-M and medical financial risk perception. CONCLUSION: This study contributes to the literature by enhancing our understanding of the factors that influence behavioral intention regarding medical care avoidance, deepening our understanding of the role of SPA-M in medical care policy, and expanding the role of sex differences in the analysis of the relationship between SPA-M, medical financial risk perception, and medical care avoidance, offering implications for public and community health.

Adaptive Optical Two-Photon Fluorescence Microscopy Probes Cellular Organization of Ocular Lenses In Vivo.

Purpose: The mammalian ocular lens is an avascular multicellular organ that grows continuously throughout life. Traditionally, its cellular organization is investigated using dissected lenses, which eliminates in vivo environmental and structural support. Therefore, in vivo optical imaging methods for studying lenses in their native context in live animals are urgently needed. Methods: Here, we demonstrated that two-photon fluorescence microscopy can visualize lens cells in vivo. To maintain subcellular resolution at depth, we used adaptive optics to correct aberrations owing to ocular and lens tissues, which led to substantial signal and resolution improvements. Results: Imaging lens cells up to 980 µm deep, we observed novel cellular organizations including suture-associated voids, enlarged vacuoles, and large cavities, contrary to the conventional view of a highly ordered organization. We tracked these features longitudinally over weeks and observed the incorporation of new cells during growth. Conclusions: Taken together, noninvasive longitudinal in vivo imaging of lens morphology using adaptive optics two-photon fluorescence microscopy will allow us to observe the development or alterations of lens cellular organization in living animals directly.

Crystal Structure of a Classical MHC Class I Molecule in Dogs; Comparison of DLA-88*0 and DLA-88*5 Category Molecules.

DLA-88 is a classical major histocompatibility complex (MHC) class I gene in dogs, and allelic DLA-88 molecules have been divided into two categories named "DLA-88*0" and "DLA-88*5." The defining difference between the two categories concerns an LQW motif in the α2 domain helical region of the DLA-88*5 molecules that includes the insertion of an extra amino acid compared to MHC class I consensus length. We here show that this motif has been exchanged by recombination between different DLA-88 evolutionary lineages. Previously, with pDLA-88*508:01, the structure of a molecule of the DLA-88*5 category was elucidated. The present study is the first to elucidate a structure, using X-ray crystallography, of the DLA-88*0 category, namely DLA-88*001:04 complexed with ß2m and a nonamer peptide derived from canine distemper virus (CDV). The LQW motif that distinguishes DLA-88*5 from DLA-88*0 causes a shallower peptide binding groove (PBG) and a leucine exposed at the top of the α2 domain helix expected to affect T cell selection. Peptide ligand amino acid substitution and pMHC-I complex formation and stability analyses revealed that P2 and P3 are the major anchor residue positions for binding to DLA-88*001:04. We speculate that the distribution pattern of the LQW motif among canine classical MHC class I alleles represents a strategy to enhance allogeneic rejection by T cells of transmissible cancers such as canine transmissible venereal tumor (CTVT).

Does health literacy affect older people's avoidance of medical care? The sense of medical care policy alienation and perceptions of control.

We aimed to clarify whether health literacy (HL)  impacts medical care avoidance through an underexplored mediator: a sense of policy alienation towards medical care policy for residents (SPA-M). A moderated mediation model with control perception as a moderator was used to analyze the inner relationship between HL and SPA-M. A cross-sectional survey of 470 people ≥ 60 years old, revealed a significant negative association between HL and medical care avoidance intention, which bootstrapped moderated mediation analysis confirmed is partially mediated by SPA-M. When older people's control perception was high, HL had a significant negative impact on medical care avoidance intention through SPA-M; for low control perception, the effect was insignificant. This study elucidates HL's impact of HL on medical care avoidance, highlighting control perception's relevance to medical care policymaking for older people.

Retinal microvascular and neuronal pathologies probed in vivo by adaptive optical two-photon fluorescence microscopy.

The retina, behind the transparent optics of the eye, is the only neural tissue whose physiology and pathology can be non-invasively probed by optical microscopy. The aberrations intrinsic to the mouse eye, however, prevent high-resolution investigation of retinal structure and function in vivo. Optimizing the design of a two-photon fluorescence microscope (2PFM) and sample preparation procedure, we found that adaptive optics (AO), by measuring and correcting ocular aberrations, is essential for resolving putative synaptic structures and achieving three-dimensional cellular resolution in the mouse retina in vivo. Applying AO-2PFM to longitudinal retinal imaging in transgenic models of retinal pathology, we characterized microvascular lesions with sub-capillary details in a proliferative vascular retinopathy model, and found Lidocaine to effectively suppress retinal ganglion cell hyperactivity in a retinal degeneration model. Tracking structural and functional changes at high-resolution longitudinally, AO-2PFM enables microscopic investigations of retinal pathology and pharmacology for disease diagnosis and treatment in vivo.

Adaptive optical two-photon fluorescence microscopy probes cellular organization of ocular lenses in vivo.

The mammalian ocular lens is an avascular multicellular organ that grows continuously throughout life. Traditionally, its cellular organization is investigated using dissected lenses, which eliminates in vivo environmental and structural support. Here, we demonstrated that two-photon fluorescence microscopy (2PFM) can visualize lens cells in vivo. To maintain subcellular resolution at depth, we employed adaptive optics (AO) to correct aberrations due to ocular and lens tissues, which led to substantial signal and resolution improvements. Imaging lens cells up to 980 µm deep, we observed novel cellular organizations including suture-associated voids, enlarged vacuoles, and large cavities, contrary to the conventional view of a highly ordered organization. We tracked these features longitudinally over weeks and observed the incorporation of new cells during growth. Taken together, non-invasive longitudinal in vivo imaging of lens morphology using AO 2PFM will allow us to directly observe the development or alterations of lens cellular organization in living animals.

Conversion Hip Arthroplasty Using Standard and Long Stems after Failed Internal Fixation of Intertrochanteric Fractures.

OBJECTIVE: Failed internal fixation of intertrochanteric fractures (FIF-ITF) is often treated by conversion hip arthroplasty (CHA). This study aimed to evaluate the results and complications of using standard and long femoral stems in this operation. METHODS: This retrospective, multi-center study enrolled 31 total hip arthroplasty (THA) and 23 hemiarthroplasties (HA) cases (30 women, 24 men; mean age 76 years) after FIF-ITF between 2012 and 2019, divided into two groups: standard stem group (n = 20) and long stem group (n = 34). The initial internal fixation includes 38 cases of proximal femoral nail anti-rotation (PFNA), eight cases of the dynamic hip screw (DHS), and eight cases of locking proximal femoral plate (LPFP). The indications for CHA included 38 cases of failure of fixation, seven cases of nonunion, and nine cases of avascular necrosis or posttraumatic osteoarthritis. Perioperative data and complications related to fracture and operation were collected, and preoperative and postoperative clinical and radiological data were analyzed. Clinical outcomes were assessed using Harris hip score (HHS) and 36-item Short Form survey (SF-36: including physical function (PF) score and body pain (BP) score). Statistical analyses were performed using the chi-square or Fisher's exact test, and the 2-sample t-test or Wilcoxon rank sum test. RESULTS: At an average of 5.6 years with a minimum of 2 years follow-up. A significant overall surgeon-related complication rate was detected (27.8% [15/54]), five cases had an intraoperative femur fracture, one case had a late periprosthetic femoral fracture, two cases had a stem penetration, one case had a cement leakage, and two patients had an early postoperative dislocation, one infection and three cases of stem loosening or subsidence. Long stems had an increased risk of complication (13/34) compared to standard stems (2/20) (P = 0.031). The operation time and blood loss in the long stem group were higher than those in the standard stem group (P = 0.002; 0.017). HHS and SF-36 significantly improved in both groups from preoperative to the final follow-up and did not present significant differences at the final follow-up (P > 0.05). CONCLUSION: CHA following FIF-ITF showed a successful mid-term clinical result, long stem arthroplasty should be approached with caution for the risks of higher complication rate, especially intraoperative femoral fractures.