TRAF6 enhances PD-L1 expression through YAP1-TFCP2 signaling in melanoma

Immunotherapy represented by programmed cell death protein 1 (PD-1)/programmed death ligand 1 (PD-L1) monoclonal antibodies has led tumor treatment into a new era. However, the low overall response rate and high incidence of drug resistance largely damage the clinical benefits of existing immune checkpoint therapies. Recent studies correlate the response to PD-1/PD-L1 blockade with PD-L1 expression levels in tumor cells. Hence, identifying molecular targets and pathways controlling PD-L1 protein expression and stability in tumor cells is a major priority. In this study, we performed a Stress and Proteostasis CRISPR interference screening to identify PD-L1 positive modulators. Here, we identified TRAF6 as a critical regulator of PD-L1 in melanoma cells. As a non-conventional E3 ubiquitin ligase, TRAF6 is inclined to catalyze the synthesis and linkage of lysine-63 (K63) ubiquitin which is related to the stabilization of substrate proteins. Our results showed that suppression of TRAF6 expression down-regulates PD-L1 expression on the membrane surface of melanoma cells. We then used in vitro and in vivo assays to investigate the biological function and mechanism of TRAF6 and its downstream YAP1/TFCP2 signaling in melanoma. TRAF6 stabilizes YAP1 by K63 poly-ubiquitination modification, subsequently promoting the formation of YAP1/TFCP2 transcriptional complex and PD-L1 transcription. Inhibition of TRAF6 by Bortezomib enhanced cytolytic activity of CD8+ T cells by reduction of endogenous PD-L1. Notably, Bortezomib enhances anti-tumor immunity to an extent comparable to anti-PD-1 therapies with no obvious toxicity. Our findings reveal the potential of inhibiting TRAF6 to stimulate internal anti-tumor immunological effect for TRAF6-PD-L1 overexpressing cancers.

Cochlear implantation for rare Streptococcus suis meningitis with hearing loss

OBJECTIVES

This study aimed to explore the diagnostic sensitivity of 3D heavily weighted T2-weighted MRI (T2MRI) and high-resolution computed tomography (HRCT) in patients with cochlear fibrosis associated with Streptococcus suis (S. suis) meningitis and the practicality of Cochlear implantation (CI) treatments.

METHODS

Between January 2020 and December 2022, we enrolled four patients with rare cochlear S. suis meningitis with associated hearing loss despite aggressive or non-aggressive follow-up antibiotic treatment. Clinical imaging data, surgical performances and post-surgical-electrode impedance were evaluated.

RESULTS

Combined with HRCT and T2MRI, the cochlea had varying degrees of fibrosis and ossification in different cases. However, the electrodes were successfully and wholly inserted after intraoperative removal of the ossified and fibrotic foci. Post-surgical electrode impedance values of MP1 + 2 mode were normal in all 4 cases at initial activation.

CONCLUSION

In patients with S. suis meningitis and associated cochlear fibrosis, T2MRI examination of the inner ear was more sensitive than HRCT. This research highlights the feasibility of CI treatment in S. suis meningitis patients with severe cochlear fibrosis.

Artificial Intelligence for Rhinoplasty Design in Asian Patients

BACKGROUND

Rhinoplasty is one of the most challenging plastic surgeries because it lacks a uniform standard for preoperative design or implementation. For a long time, rhinoplasties were done without an accurate consensus of aesthetic design between surgeons and patients before surgery and consequently brought unsatisfactory appearance for patients. In recent years, three-dimensional (3D) simulation has been used to visualize the preoperative design of rhinoplasty, and good results have been achieved. However, it still relied on individual aesthetics and experience. The preoperative design remained a huge challenge for inexperienced surgeons and could be time-consuming to perform manually. Therefore, we adopted artificial intelligence (AI) in this work to provide a new idea for automated and efficient preoperative nasal contour design.

METHODS

We collected a dataset of 3D facial images from 209 patients. For each patient, both the original face and the manually designed face using 3D simulation software were included. The 3D images were transformed into point clouds, based on which we used the modified FoldingNet model for deep neural network training (by pytorch 1.12).

RESULTS

The trained AI model gained the ability to perform aesthetic design automatically and achieved similar results to manual design. We analysed the 1027 facial features captured by the AI model and concluded two of its possible cognitive modes. One is to resemble the human aesthetic considerations while the other is to fulfil the given task in a special way of the machine.

CONCLUSION

We presented the first AI model for automated preoperative 3D simulation of rhinoplasty in this study. It provided a new idea for the automated, individual and efficient preoperative design, which was expected to bring a new paradigm for rhinoplasty and even the whole field of plastic surgery.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Relevant Research of Inflammatory Cytokines Spectrum in Peripheral Blood of Sudden Hearing Loss

OBJECTIVE

To investigate whether there is a correlation between the inflammatory state and the pathogenesis and clinical features of sudden hearing loss (SHL) by studying the expression of inflammation-related cytokines in the peripheral blood of patients with SHL.

METHODS

In this work, we analyzed the cytokine profiles of 48 analytes in 38 patients with SHL compared to 38 healthy donors using a multiplex immunoassay. This study used appropriate statistical methods to screen for inflammatory cytokines associated with the pathogenesis of SHL, to analyze their network correlation, and to analyze the relationship between clinical features of SHL and inflammatory cytokines.

RESULTS

Several cytokines, including CTACK, Eotaxin, HGF, INF-α2, IFN-β, IL-1β, IL-1ra, IL-2Rα, IL-4, IL-7, IL-8, IL-9, IL-10, IL-12(p40), IL-13, MIG, β-NGF, SCF, and TNF-α, exhibited significantly higher levels in the peripheral blood of the SHL group compared to the control group. An inflammatory network composed of multiple cytokines, including IL-1β, is a risk factor for the development of SHL.

CONCLUSION

This study identified several inflammatory cytokines with elevated expression, which may be linked with the onset of SHL. The results of this study also provide a basis for the theoretical hypothesis of inflammation in SHL.

LEVEL OF EVIDENCE

III Laryngoscope, 2024.

Autologous Shuffling Lipo-Aspirated Fat Combined Mechanical Stretch in Revision Rhinoplasty for Severe Contractures in Asian Patients

BACKGROUND

A severely contracted nose is a common occurrence. Intraoperative expansion is not sufficient to soften the severely constricted nasal envelope, which poses challenges in revision rhinoplasty. In recent years, adjuvant therapies, including nasal fat grafting and cell component injection, are applied before revision rhinoplasty to soften the nasal envelope. Herein, autologous shuffling lipo-aspirated fat and manual mechanical stretch were combined as adjuvant therapy before revision rhinoplasty.

METHODS

A total of 24 patients with severe nasal contracture were included in this study. Of these, 8 received autologous shuffling lipo-aspirated fat and manual mechanical stretch before revision rhinoplasty (comprehensive therapy), 8 underwent mechanical stretch and revision rhinoplasty, and 8 patients underwent only revision rhinoplasty. The objective and subjective outcome assessment was processed in the follow-up period of 6 months. Nasal length, nasal tip projection, nasofrontal angle, and nasolabial angle were measured, and potential complications were assessed.

RESULTS

All 24 patients underwent a successful revision rhinoplasty. In the comprehensive therapy group, no patient had postoperative wound infection and defect of the nasal column mucous. The comprehensive treatment group had the most significant improvement in nasal length and nasal tip projection, and the nasolabial angle was the closest to 90°, which indicated the most effective nasal revision and aesthetic contour.

CONCLUSIONS

The adjuvant therapy combines autologous shuffling lipo-aspirated fat and manual mechanical stretch before revision rhinoplasty could effectively improve the surgical outcome and decrease the postoperative complications regarding severe nasal contractures.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Use of nasal septal bone to straighten septal L-Strut in correction of east Asian short nose: A retrospective study

BACKGROUND

The perpendicular plate of ethmoid (PPE) was used to correct short noses in rhinoplasty in Asians, but the safe harvest of the plate and the assessment of its clinical application has been perplexing to plastic surgeons.

AIMS

To explore how to safely cut the perpendicular plate of ethmoid bone and evaluate its application effect.

PATIENTS/METHODS

A finite element model was established to guide the clinical operation. A total of 30 patients with short noses were selected. Among them, 15 patients used autologous septal cartilage to lengthen the nasal tip, and 15 patients used the PPE to strengthen the L-shape nasal septum. The differences in the esthetic parameters of the nose, complications, and patients' satisfaction were compared between the two groups.

RESULTS

Significant differences were noted in the nasal dorsal length (p = 0.001), Goode's ratio (p = 0.001), and nasofrontal angle (p = 0.003) after rhinoplasty, and no significant differences were noted in any of the esthetic parameters between the two groups. The symptoms of nasal obstruction in the experimental group were significantly lighter than those in the control group (p = 0.04). There was no statistically significant difference in the doctors' assessment of outcomes between the two groups (p = 0.48).

CONCLUSION

The safest region to harvest the PPE is in the middle and lower third. Rhinoplasty improves the esthetics of the patient's nose. The PPE used to strengthen the L-shape nasal septum structure has a smaller probability of nasal septal deviation with the time in Asian short noses.

Metal-Organic Frameworks-Based Memristors: Materials, Devices, and Applications

Facing the explosive growth of data, a number of new micro-nano devices with simple structure, low power consumption, and size scalability have emerged in recent years, such as neuromorphic computing based on memristor. The selection of resistive switching layer materials is extremely important for fabricating of high performance memristors. As an organic-inorganic hybrid material, metal-organic frameworks (MOFs) have the advantages of both inorganic and organic materials, which makes the memristors using it as a resistive switching layer show the characteristics of fast erasing speed, outstanding cycling stability, conspicuous mechanical flexibility, good biocompatibility, etc. Herein, the recent advances of MOFs-based memristors in materials, devices, and applications are summarized, especially the potential applications of MOFs-based memristors in data storage and neuromorphic computing. There also are discussions and analyses of the challenges of the current research to provide valuable insights for the development of MOFs-based memristors.

PHF6 functions as a tumor suppressor by recruiting methyltransferase SUV39H1 to nucleolar region and offers a novel therapeutic target for PHF6-muntant leukemia

Mutations in the plant homeodomain-like finger protein 6 (PHF6) gene are strongly associated with acute myeloid (AML) and T-cell acute lymphoblastic leukemia (T-ALL). In this study, we demonstrated that PHF6 can bind to H3K9me3 and H3K27me1 on the nucleolar chromatin and recruit histone methyltransferase SUV39H1 to the rDNA locus. The deletion of PHF6 caused a decrease in the recruitment of SUV39H1 to rDNA gene loci, resulting in a reduction in the level of H3K9me3 and the promotion of rDNA transcription. The knockdown of either SUV39H1 or PHF6 significantly attenuated the effects of increase in H3K9me3 and suppressed the transcription of rDNA induced by the overexpression of the other interacting partner, thereby establishing an interdependent relationship between PHF6 and SUV39H1 in their control of rRNA transcription. The PHF6 clinical mutants significantly impaired the ability to bind and recruit SUV39H1 to the rDNA loci, resulting in an increase in rDNA transcription activity, the proliferation of in vitro leukemia cells, and the growth of in vivo mouse xenografts. Importantly, significantly elevated levels of pre-rRNA were observed in clinical AML patients who possessed a mutated version of PHF6. The specific rDNA transcription inhibitor CX5461 significantly reduced the resistance of U937 AML cells deficient in PHF6 to cytarabine, the drug that is most commonly used to treat AML. Collectively, we revealed a novel molecular mechanism by which PHF6 recruits methyltransferase SUV39H1 to the nucleolar region in leukemia and provided a potential therapeutic target for PHF6-mutant leukemia.

Biological Activities and Emerging Roles of Lignin and Lignin-Based Products─A Review

Bioactive substances, displaying excellent biocompatibility, chemical stability, and processability, could be extensively applied in biomedicine and tissue engineering. In recent years, plant-based bioactive substances such as flavonoids, vitamins, terpenes, and lignin have received considerable attention due to their human health benefits and pharmaceutical/medical applications. Among them is lignin, an amorphous biomacromolecule mainly derived from the combinatorial radical coupling of three phenylpropane units (p-hydroxypenyl, guaiacyl, and syringyl) during lignification. Lignin possesses intrinsic bioactivities (antioxidative, antibacterial, anti-UV activities, etc.) against phytopathogens. Lignin also enhances the plant resistance (adaptability) against environmental stresses. The abundant structural features of lignin offer other significant bioactivities including antitumor and antivirus bioactivities, regulation of plant growth, and enzymatic hydrolysis of cellulose. This Review reports the latest research results on the bioactive potential of lignin and lignin-based substances in biomedicine, agriculture, and biomass conversion. Moreover, the interfacial reactions and bonding mechanisms of lignin with biotissue/cells and other constituents were also discussed, aiming at promoting the conversion or evolution of lignin from industrial wastes to value-added bioactive materials.

Cellular nanovesicles with bioorthogonal targeting enhance photodynamic/photothermal therapy in psoriasis

The interaction between over-proliferating keratinocytes and excessive activated immune cells contributes to the development and progression of psoriasis. Photodynamic therapy (PDT)/photothermal therapy (PTT) is a promising method to treat skin diseases due to their synergistic effect and low side effect. Cell membrane is an ideal cell-mediated drug delivery platform with inherent biocompatibility, but lacks of specific targeting properties to increase drug accumulation in the psoriatic site. Here, we develop a new PDT/PTT strategy to treat psoriasis, based on cell membrane functionalization by metabolic glycoengineering with unnatural sugars, which label cell membranes with chemical tags for subsequent targeting. In our study, in order to enhance the PDT/PTT effect, N₃-labeled cell membrane-derived nanovesicles coated with IR-780 nanoparticals (N₃-NV-INPs) are constructed, which can specifically recognize DBCO-modified psoriatic lesions through bioorthogonal click chemistry to achieve targeted PDT/PTT effect. The results showed that N₃-NV-INPs could specifically target the psoriatic lesions, enhance the synergistic effect of PDT/PTT under the irradiation of near-infrared light, exhaust excessive proliferation of keratinocytes, regulate immunity, reduce the release of cytokines, such as IL-17, IL-22, TNF-α, improve epidermal hyperplasia, and effectively relieve the symptoms of psoriasis. Taken together, we constructed cellular nanovesicles based on an alternative artificial targeting strategy to enhance PDT/PTT effect in psoriasis, which shows great potential in clinical application. STATEMENT OF SIGNIFICANCE: The major challenge in the treatment of psoriasis is how to effectively deliver drugs to the lesions to exhaust overproliferating keratinocytes and modulate immunity. A newly-developed cell membrane-coating technology combined with biorthogonal targeted delivery promotes more drug accumulation at the lesions of the disease. Incorporation of an effective photosensitizer into the lesions of psoriasis site results in exert PDT/PTT effect under the irradiation of near-infrared light. The synergistic PDT/PTT effect can effectively exhaust keratinocytes and immune cells in the epidermis and dermis, reduce the release of inflammatory cytokines, and relieve the symptoms of psoriasis. This unique functional cell membrane nanovesicles combined with bioorthogonal targeting is applied to enhance the PDT/PTT effect in psoriasis and may provide a solution for the clinical treatment of other inflammatory skin diseases.

Propofol alleviates intestinal ischemia/reperfusion injury in rats through p38 MAPK/NF-κB signaling pathway

OBJECTIVE

The aim of this study was to investigate the influences of propofol on intestinal ischemia/reperfusion (I/R) injury in rats through the p38 mitogen-activated protein kinase (MAPK)/nuclear factor-kappa B (NF-κB) signaling pathway.

MATERIALS AND METHODS

The models of intestinal I/R injury were first successfully established. All rats were randomly divided into 4 groups, namely, S group, I/R group, P group and P + S group. Pathological-morphological changes, injury score and wet-to-dry weight ratio of intestinal tissues as well as oxidative stress indexes in each group of rats were detected. Enzyme-linked immunosorbent assay (ELISA) was applied to measure the levels of inflammatory factors such as creatine kinase-MB (CK-MB), tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) in each group of rats. Furthermore, Western blotting (WB) assay was applied to determine the protein expression levels of p38 MAPK and NF-κB in different groups.

RESULTS

Intestinal tissue injury was the severest in I/R group, with the infiltration of massive inflammatory cells and oozing of blood (Figure 1A, I/R). Compared with those in I/R group, the infiltration of inflammatory cells and damage to intestinal villi were notably relieved in P group and P + S group, revealing that the intestinal mucosal injury was remarkably repaired in P group and P + S group (Figure 1A, P). Moreover, the intestinal tissue injury score was evidently higher in I/R group, P group and P + S group than that in S group (p<0.05). However, it was markedly lower in P group and P + S group than that in I/R group (p<0.05). I/R group, P group and P + S group exhibited significantly increased wet-to-dry weight ratio of intestinal tissues in comparison with S group (p<0.05). However, P group and P + S group exhibited distinctly lower wet-to-dry weight ratio of intestinal tissues than I/R group (p<0.05). The content of malondialdehyde (MDA) was reduced prominently, while that of superoxide dismutase (SOD) was elevated significantly in P group and P + S group in contrast with those in I/R group (p<0.05). On the contrary, P + S group displayed remarkably lower MDA content and higher SOD content than P group (p<0.05). The levels of CK-MB, TNF-α and IL-6 in the blood rose markedly in I/R group compared with those in S group (p<0.05). However, they declined evidently in P group and P + S group in contrast with those in I/R group (p<0.05). Besides, the protein expression level of phosphorylated p38 MAPK was significantly higher in I/R group, P group and P + S group than that in S group (p<0.05). However, no significant difference was observed in the protein expression of total p38 MAPK among the four groups (p>0.05). However, the protein expression level of phosphorylated p38 MAPK was distinctly down-regulated in P group and P + S group in comparison with that in I/R group (p<0.05). Finally, I/R group, P group and P + S group had a prominently higher protein expression level of NF-κB than S group (p<0.05). However, P group and P + S group exerted a significantly lower protein expression level of NF-κB than I/R group (p<0.05).

CONCLUSIONS

Propofol decreases the release of inflammatory factors and alleviates intestinal edema by inhibiting the p38 MAPK/NF-κB signaling pathway, thereby mitigating and treating the intestinal I/R injury in rats.

Sevoflurane ameliorates adriamycin-induced myocardial injury in rats through the PI3K/Akt/GSK-3β pathway

OBJECTIVE

The aim of this study was to explore the effects of sevoflurane (SEV) pretreatment on Adriamycin (ADR)-induced myocardial injury through the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/glycogen synthase kinase-3β (GSK-3β) pathway.

MATERIALS AND METHODS

A total of 24 rats weighing 200-250 g were divided into four groups, including: control group (C group), ADR injection group (ADR group), SEV pretreatment group (ADR + SEV group) and inhibitor group (ADR + SEV + LY group). H9c2 cells were cultured in vitro and were divided into control group (C group), ADR treatment group (ADR group), and SEV pretreatment group (ADR + SEV group) and inhibitor group (ADR + SEV + LY group) as well. Next, the content of aspartate aminotransferase (AST), lactate dehydrogenase (LDH) and creatine kinase (CK) in the serum was detected via Enzyme-Linked Immunosorbent Assay (ELISA). Hematoxylin-eosin (HE) staining assay was performed to determine the severity of myocardial injury. Meanwhile, the apoptosis rate of cells was detected through terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) assay. Additionally, Western blotting (WB) was employed to measure the protein expression levels of phosphorylated (p)-GSK-3β, p-PI3K, Akt and p-Akt.

RESULTS

Compared with C group, ADR significantly increased the content of AST, LDH and CK in the serum (p<0.01), reduced protein expression levels of p-GSK-3β, p-PI3K and p-Akt (p<0.01), increased apoptosis rate (p<0.01), and induced myocardial injury. SEV pretreatment significantly alleviated the effect of ADR, manifested as significantly lowered content of AST, LDH and CK in the serum (p<0.01), distinctly elevated protein expression levels of p-GSK-3β, p-PI3K and p-Akt (p<0.01), notably reduced apoptosis rate (p<0.01), and relieved myocardial injury. LY294002 remarkably inhibited the protective effect of SEV against myocardial injury (p<0.01) CONCLUSIONS: SEV is able to prominently ameliorate ADR-induced myocardial injury by regulating the phosphorylation level of the PI3K/Akt/GSK-3β signaling pathway.

[Clinical characteristics and efficacy analysis of secondary benign paroxysm positional vertigo after middle ear surgery]

Objective:To investigate the clinical characteristics and therapeutic effect of benign paroxysm positional vertigo（BPPV） secondary to middle ear surgery. Method:A total of 1 126 patients who underwent tympanoplasty or radical mastoidectomy due to chronic suppurative otitis media and middle ear cholesteatoma in our hospital from January 2014 to December 2018 were collected. Clinical data of BPPV within 1 month after surgery were collected, The incidence, incidence side, involved semicircular canal, onset time, age of onset, and duration of operation of secondary BPPV after middle ear surgery were analyzed. All patients with secondary BPPV were treated by manual reduction, and the efficacy was evaluated 1 day, 1 week, and 1 month after reduction. Result:2.13% （24 cases） of patients had secondary BPPV after operation, among which 2 cases were parietal incidence. 18 cases were involved in posterior semicircular canals and 6 cases were horizontal semicircular canals. The onset time was 1-12 days after the operation, with an average of （3.29±2.44） days. The mean age of onset was （51.62±10.15） years old, and there was no statistically significant difference between the age of patients without BPPV after middle ear surgery （P>0.05）. The average operating time was （97.29±14.78） minutes, showing no statistically significant difference compared with patients in the group without BPPV （P>0.05）. Fourteen cases （58.3%） were cured and 10 cases were improved after 1 day evaluation. Evaluated 1 week after treatment, 19 cases （79.17%） were cured and 5 cases were improved. Evaluated 1 month after treatment, all patients were cured without recurrence. Conclusion:BPPV secondary to middle ear surgery often appears 3 days after surgery, and the posterior semicircular canal of the operative ear is most commonly involved. Age and operation duration have no significant influence on the incidence of BPPV, and satisfactory therapeutic effect can be obtained through manipulative reduction.

Nd2O3 Nanoparticles Induce Toxicity and Cardiac/Cerebrovascular Abnormality in Zebrafish Embryos via the Apoptosis Pathway

Introduction

Rare-earth nanoparticles in the environment and human body pose a potential threat to human health. Although toxic effects of rare-earth nanoparticles have been extensively studied, the effects on the early development are not well understood. In this study, we attempted to explain the toxic effects of neodymium oxide (Nd₂O₃) nanoparticles on early development.

Methods

We added the Nd₂O₃ nanoparticles at different concentrations and recorded the mortality and malformation rate per 24 hrs under a microscope. The live embryos treated with Nd₂O₃ nanoparticles were imaged as movies and Z step lapses with a confocal microscope, and heart rates were counted for 30 s to measure the cardiac function. The live Tg (Flk1:EGFP) transgenic embryos exposed to Nd₂O₃ nanoparticles were observed under confocal microscope to measure the cerebrovascular development. Subsequently, we extracted the total protein for Western blot at 5 days post-fertilisation (dpf). Embryos were collected to undergo TUNEL staining for apoptosis detection.

Results

Nd₂O₃ nanoparticles disturbed embryo development at high concentrations (>200 μg/mL). The mortality and malformation rate gradually increased in a dose-dependent manner by morphological observation, while the Nd₂O₃ median lethal concentration (LD50) was 203.4 μg/mL at 120 hrs post-fertilisation (hpf). Furthermore, the Nd₂O₃-treated embryos showed severe arrhythmia and reduced heart rate. We also observed the markedly cerebrovascular disappearance at middle concentration (100 and 200 μg/mL). The downregulated autophagy flux in brain blood vessels and increased apoptosis level in neurons might affect vessels sprouting and contribute to the vanished cerebrovascular.

Conclusion

The results suggested that the embryos exposed to Nd₂O₃ activated the apoptosis pathway and induced toxicity and abnormal cardiac/cerebrovascular development.

[Clinical effects of Kirschner wire with hole transverse fixation combined with titanium cable purse string suture for the treatment of refractory fracture of patellar comminuted fracture]

OBJECTIVE

To explore clinical effects of Kirschner wire with hole transverse fixation combined with titanium cable purse string suture in treating refractory fracture of patellar comminuted fracture.

METHODS

From January 2014 to January 2016, 17 comminuted fracture treated by Kirschner wire with hole transverse fixation combined with titanium cable purse string suture were retrospectively analyzed, including 10 males and 7 females aged from 28 to 67 years old with an average of (48.7±3.2) years old. According to AO/OTA fracture classification, all fractures were type 34-C3.2. Operative time, blood loss, intervals of the first functional exercise postoperatively and complications were observed. Meanwhile, function recovery was evaluated by Böstman scoring at 10 months after operation.

RESULTS

All patients were followed up with an average of(14.6±2.1) months ranged from 10 to 24 months. All incisions healed at stage I. Clinical fracture healing time ranged from 11.7 to 16.5 weeks with an average of (12.7±1.7) weeks; operative time ranged from 67 to 95 min with an average of (71.4±11.5) min; blood loss ranged from 41 to 72 ml with an average of (57.0±7.5) ml; the first time of functional exercise ranged from 2 to 5 d with an average of (2.2±1.7) d. No complications including Kirschner pin stabbing the skin, loose or slippery of Kirschner pin, bursitis with pain brought by tip of Kirschner pin, wire escaped and broken occurred. Postoperative Böstman score at 10 months were 28.15±1.74, 12 patients got excellent results, 4 well and 1 lose.

CONCLUSIONS

Kirschner wire with hole transverse fixation combined with titanium cable purse string suture in treating refractory fracture of patellar comminuted fracture has advantages of simple operation, good anatomical reduction, stable fixation and less complications, which is worth popularizing.

Preparation, characterization and application research of a sustained dexamethasone releasing electrode coating for cochlear implantation

Cochlear inflammatory response after cochlear implantation (CI) is an important mechanism for implantation trauma and hearing loss. The hearing loss was also caused by damage to auditory hair cells (HCs), whereas ion homeostasis within the cochlea can ensure survival of HCs. In our study, pure hyaluronic acid (HA) was crosslinked with 1, 4-butanediol diglycidyl ether (BDDE) and the successful preparation of the cross-linked hydrogel (CHA) was confirmed by rheological characteristics and FTIR spectra. Artificial perilymph (APL) was prepared to simulate the ion homeostasis microenvironment within scala tympani of human cochlear, and served as the major component of artificial perilymph soaked CHA (APL-CHA). The conductivity experiment indicated that APL-CHA is more suitable to the requirements of the electrical conductivity in scala tympani. The electrode coating process found that the extrusion coating method have advantages of controllable adhesive capacity of APL-CHA, uniform coating thickness and smooth surface as compared to common method. Due to CI surgery application requirement, optimization of coating process was selected as follows: extrusion coating method, degree of 3.6 vol%, pinhole diameter of 32G (110 μm), pressure of 200 ± 15.81 Psi. Controlled dexamethasone 21-phosphate sodium salt (DSP) release of 20 days could be demonstrated using the hydrogel filled reservoir via a validated HPLC method. The morphological structure of CHA showed different sizes of porous structure among APL-CHA provided structural basis for drug delivery. L929 fibroblasts culture and Spiral Ganglion Neuron Explants culture results revealed that APL-CHA possesses fine biological compatibility. APL-CHA shows a promising application in CI surgery and has great potential in preventing hearing loss with well simulation of ion homeostasis within the cochlear, local DSP delivery for target anti-inflammatory, approximate conductivity within the scala tympani and optimization of electrode coating process.

One-pot synthesis of propynoates and propynenitriles

An efficient transformation towards propynoates and propynenitriles is herein described. The practical methodology was conducted at low temperature (–78 or –60 °C) in a one-pot manner with the assistance of base rather than any transition metal catalysts. The base-induced protocol exhibits good functional group tolerance (up to 28 examples) and high efficiency (up to 92% yields) towards substituted acetylenes of great synthetic significance, which was also well demonstrated by the gram-scale reactions.

An MnO2 nanosheet as a label-free nanoplatform for homogeneous biosensing

An ultrathin MnO2 nanosheet is established as a label-free two-dimensional nanoplatform for homogeneous biosensing. Two biosensors based on an MnO2 nanosheet with favourable performances are constructed for OTA and Cat D using different probes and following different sensing principles.

[The impact of malleus processing in ossicular chain reconstruction on the therapeutic effect in patients with tympanosclerosis]

OBJECTIVE

To investigate the effect of different malleus treatments on the postoperative efficacy in the tympanosclerosis patients receiving ossicular chain reconstruction.

METHOD

Fifty-nine patients (62 ears) with tympanosclerosis were treated by ossicular chain reconstruction. All the patients were divided into three groups, including malleus removal group (A, 24 ears), retaining only the malleus handle group (B, 18 ears) and the intact malleus group (C, 20 ears). All the patients were followed up 3 months pre-operation, 3 months and 1 year post-operation by audiometric measurement (the average hearing threshold at 0.5, 1.0, 2.0 kHz HI). Tympanic membrane was examined by ear endoscope.

RESULT

The pre-operation mean air bone gap (ABG) in these groups were 40.07 +/- 77.56 dB, 37.31 +/- 76.45 dB, and 36.75 +/- 76.72 dB, among which the difference had no statistical significance (P > 0.05). At 3 months after operation, the ABG in all cases was improved at 0.5, 1 and 2 kHz. The difference of ABG improvement among these three groups had no statistical significance (P > 0.05). One year after surgery, the ABG of the three groups were decreased by 17.92 +/- 9.28 dB, 16.76 +/- 5.19 dB and 10.58 +/- 7.38 dB respectively. The hearing improvement in group C is less than the other two groups (P = 0.03, P = 0.016). The difference of hearing improvement between group A and group B had no statistical significance(P > 0.05). Group A and group B each have one case of tympanic membrane perforation and artificial ossicle falling off.

CONCLUSION

The operating processes of malleus in ossicular chain reconstruction of patients with tympanosclerosis were introduced. In terms of short-term efficacy, the three groups showed no significant difference. However, the long-term efficacy of the patients in the group A and group B were better compared with the group C.

Recovery of high purity sulfuric acid from the waste acid in toluene nitration process by rectification

Waste sulfuric acid is a byproduct generated from numerous industrial chemical processes. It is essential to remove the impurities and recover the sulfuric acid from the waste acid. In this study the rectification method was introduced to recover high purity sulfuric acid from the waste acid generated in toluene nitration process by using rectification column. The waste acid quality before and after rectification were evaluated using UV-Vis spectroscopy, GC/MS, HPLC and other physical and chemical analysis. It was shown that five nitro aromatic compounds in the waste acid were substantially removed and high purity sulfuric acid was also recovered in the rectification process at the same time. The COD was removed by 94% and the chrominance was reduced from 1000° to 1°. The recovered sulfuric acid with the concentration reaching 98.2 wt% had a comparable quality with commercial sulfuric acid and could be recycled back into the toluene nitration process, which could avoid waste of resources and reduce the environmental impact and pollution.

[Applied anatomy of scala tympani inlet related to cochlear implantation]

OBJECTIVE

To investigate the related parameters of the temporal bone structure for determining the position of implanting electrode into the scala tympani in cochlear implantation surgery through the facial recess and epitympanum approach.

METHODS

In a surgical simulation experiment, 20 human temporal bones were studied and measured to determine the related parameters of the temporal bone structure.

RESULTS

The distance 5.91∓0.29 mm between the short process of the incus and the round window niche, 2.11∓0.18 mm between the stapes and the round window niche, 6.70∓0.19 mm between the facial nerve in the perpendicular paragraph and the round window niche, 2.22∓0.21 mm from the pyramidal eminence to the round window, and 2.16∓0.14 mm between the stapes and the round window. The minimal distance between the implanting electrode and the vestibular window was 2.12∓0.19 mm. The distance between the cochleariform process and the round window niche was 3.79∓0.17 mm. The position of the cochlear electrode array insertion into the second cochlear turn was 2.25∓0.13 mm under the stapes. The location of the cochlear electrode array insertion into the second cochlear turn was 2.28∓0.20 mm inferior to the pyramidal eminence.

CONCLUSION

These parameters provide a reference value to determine the different positions of cochlear electrode array insertion into the scale tympani in different patients.

[Applied anatomy of facial recess and posterior tympanum related to cochlear implantation]

OBJECTIVE

To investigate the related parameters of temporal bone structure in the surgery of cochlear implantation through facial recess approach so as to offer a theoretical reference for the avoidance of facial nerve injury and the accurate localization.

METHOD

In a surgical simulation experiment, twenty human temporal bones were studied. The correlation parameters were measured under surgical microscope.

RESULT

Distance between suprameatal spine and short process of incus was (12.44 +/- 0.51) mm. Width from crotch of chorda tympani nerve to stylomastoid foramen was (2.67 +/- 0.51) mm. Distance between short process of incus and crotch of chorda tympani nerve was (15.22 +/- 0.83) mm. The location of maximal width of the facial recess into short process of incus, crotch of chorda tympani nerve were (6.28 +/- 0.41) mm, (9.81 +/- 0.71) mm, respectively. The maximal width of the facial recess was (2.73 +/- 0.20) mm. The value at level of stapes and round window were (2.48 +/- 0.20 mm) and (2.24 +/- 0.18) mm, respectively. Distance between pyramidalis eminence and anterior round window was (2.22 +/- 0.21) mm. Width from stapes to underneath round window was (2.16 +/- 0.14) mm.

CONCLUSION

These parameters provide a reference value to determine the position of cochlear inserting the electrode array into the scale tympani and opening facial recess firstly to avoid potential damage to facial nerve in surgery.

A simple, economical, and effective portable paediatric mock circulatory system

Ventricular assist devices (VADs) and total artificial hearts have been in development for the last 50 years. Since their inception, simulators of the circulation with different degrees of complexity have been produced to test these devices in vitro. Currently, a new path has been taken with the extensive efforts to develop paediatric VADs, which require totally different design constraints.

This paper presents the manufacturing details of an economical simulator of the systemic paediatric circulation. This simulator allows the insertion of a paediatric VAD, includes a pumping ventricle, and is adjustable within the paediatric range. Rather than focusing on complexity and physiological simulation, this simulator is designed to be simple and practical for rapid device testing.

The simulator was instrumented with medical sensors and data were acquired under different conditions with and without the new PediaFlow™ paediatric VAD. The VAD was run at different impeller speeds while simulator settings such as vascular resistance and stroke volume were varied. The hydraulic performance of the VAD under pulsatile conditions could be characterized and the magnetic suspension could be tested via manipulations such as cannula clamping.

This compact mock loop has proven to be valuable throughout the PediaFlow development process and has the advantage that it is uncomplicated and can be manufactured cheaply. It can be produced by several research groups and the results of different VADs can then be compared easily.

[Heavy metal contamination and Pb isotopic composition in natural soils around a Pb/Zn mining and smelting area]

The heavy metal (Pb, Zn, Cr, Cu, Cd, and Hg) concentrations in the A horizon and C horizon soils, collected around the Pb/Zn mining and smelting area of Shuikoushan in Hunan, China, were investigated, and the Pb isotopic compositions were also determined to identify the potential origin of Pb in the A horizon soil. Compared with C horizon soils, the A horizon soils exhibit elevated heavy metal concentrations, especially in the vicinity of the mining and smelting area. This reveals that the surface soil was contaminated to some degree. The contents of Pb, Zn, Cr, Cu, Cd, and Hg in soils are up to 3966.88, 2086.25, 135.31, 185.63, 56.15, and 16.434 mg/kg, respectively. The potential risks caused by different metals are in the order of Cd > Hg > Pb > Cu > Zn = Cr. Much higher potential ecological risk was observed for the central area (Shuikoushan Pb/Zn mining and smelting area) than for the surrounding area. About 34%, 33%, 11%, and 22% of the sampling sites demonstrate low, moderate, considerable, and very high potential ecological risk in the central area, while about 68%, 16%, 10%, and 6% of the sampling sites show low, moderate, considerable, and very high potential ecological risk in the surrounding area, respectively. Compared with the Pb isotopic compositions in the C horizon soils (206Pb/207Pb 1.168-1.246, 208 Pb/206 Pb 2.014-2.130), the Pb in the A horizon soils has lower 206 Pb/207Pb ratios (1.166-1.226) and higher 208Pb/206Pb ratios (2.043-2. 135). The Pb in the A horizon soils predominantly derives from two-component mixing resources. One is the parent materials of C horizon, and the other is the atmospheric deposition of the smelting flue gas dust.

Developmental changes in PSD-95 and Narp mRNAs in the rat olfactory bulb

Glutamate is the main neurotransmitter in the olfactory bulb. Recently, postsynaptic-density 95 (PSD-95) and neuronal activity-regulated pentraxin (Narp) have been reported to be pivotal for targeting and clustering of NMDA receptors and AMPA receptors, respectively. We thus investigated the expressions of PSD-95 and Narp mRNAs in the rat developing olfactory bulb. PSD-95 mRNA was already expressed in most neurons on the first postnatal day (P1). On the other hand, Narp mRNA expression was weakly seen only in mitral cells on P1. Thereafter, we found initial expression of Narp mRNA on P7 in periglomerular cells, and on P14 in granular cells, indicating that in the developing olfactory bulb PSD-95 mRNA expression precedes Narp mRNA expression, and that the expression pattern of Narp mRNA seems to be well correlated with the maturation of the neurons. These results indicate that PSD-95 and Narp play important roles in making efficient excitatory synapses in the developing rat olfactory bulb, and suggest that olfactory neurons might first express PSD-95 for making efficient NMDA receptors and thereafter express Narp for efficient AMPA receptors.

Developmental changes in gephyrin and collybistin mRNA expressions in the rat olfactory bulb

GABA and glycine are inhibitory neurotransmitters in the olfactory bulb. Recently, gephyrin, a receptor-associated peripheral membrane protein, and collybistin, a gephyrin-binding protein have been shown to be pivotal for the formation of postsynaptic glycine and GABA(A) receptor clusters. In this study, we, thus, examined expressions of gephyrin and collybistin mRNAs in the developing olfactory bulb using in situ hybridization. Although collybistin has two splice variants, we found only collybistin 1 isoform mRNA in the developing olfactory bulb. On the first postnatal day (P1), mitral cells abundantly expressed gephyrin and collybistin 1 mRNAs. However, their expressions were weak or not detected in the other regions. On P3, we first detected both transcripts in granule cells. It was on P7 when periglomerular cells first showed hybridization signals for gephyrin and collybistin mRNAs. The sequence of their expressions was well correlated with that of the maturation of individual neurons, suggesting that gephyrin and collybistin 1 mRNA expressions are induced when neurons arrive at their final destinations and ready for synaptogenesis, and that they are indispensable to make efficient inhibitory synapses in the developing rat olfactory bulb.

Integrin functions play a key role in the differentiation of thymocytes in vivo

T cells express a variety of surface proteins as they develop to maturity in the thymus. In addition to the TCR-CD3 complex and the two major coreceptors, CD4 and CD8, other surface proteins expressed include receptors for cytokines, growth factors, counterreceptors, and extracellular matrix molecules. To determine the role of integrin adhesion receptors in T cell development, we have expressed a trans-dominant inhibitor of integrin function in the thymus. This inhibitor leads to a block of adhesion to fibronectin due to reduced activation of integrin receptors. This reduced adhesion leads to a partial block in differentiation from CD4-CD8- cells to CD4+CD8+ cells, after the CD25+ stage, suggesting that integrins are important during Lck-mediated differentiation. Furthermore, the overall production of CD4+ cells is reduced compared with that of CD8+ cells without changes in negative selection, suggesting that integrins may be involved in the determination of the fate of the cell as well. These results demonstrate that integrin receptor function is required for proper thymocyte development in vivo.

Crystal structure of negative cofactor 2 recognizing the TBP-DNA transcription complex

The X-ray structure of a ternary complex of Negative Cofactor 2 (NC2), the TATA box binding protein (TBP), and DNA has been determined at 2.6 A resolution. The N termini of NC2 alpha and beta resemble histones H2A and H2B, respectively, and form a heterodimer that binds to the bent DNA double helix on the underside of the preformed TBP-DNA complex via electrostatic interactions. NC2beta contributes to inhibition of TATA-dependent transcription through interactions of its C-terminal alpha helix with a conserved hydrophobic feature on the upper surface of TBP, which in turn positions the penultimate alpha helix of NC2beta to block recognition of the TBP-DNA complex by transcription factor IIB. Further regulatory implications of the NC2 heterodimer structure are discussed.

Activated protein C prevents development of phosphatidylserine-induced intrauterine growth restriction in mice

We examined the effect of activated protein C (APC) on the development of intrauterine growth restriction (IUGR) in an experimental animal model we established. The IUGR in mice was induced by artificial phosphatidylserine (PS)/phosphatidylcholine (PC) microvesicles that represent procoagulant phospholipids derived from activated platelets. This model represents the placental insufficiency associated with the phospholipid-induced hypercoagulable state in placental circulation. APC prolonged the activated partial thromboplastin time (aPTT) using mouse plasma and dose dependently inhibited thrombin generation in a chromogenic assay in defibrinated plasma of mice. Administration of exogenous APC at concentrations that maximally inhibited thrombin generation in defibrinated plasma prevented a significant reduction in fetal body weight and induced marked histological changes including congestion and fibrin depositions in IUGR mouse placentas. These results suggest that the inhibition of thrombin generation in the placental circulation by APC prevents the development of IUGR that is dependent on coagulation associated with PS/PC from activated platelets.

Identification of two residues in MCM5 critical for the assembly of MCM complexes and Stat1-mediated transcription activation in response to IFN-gamma

In response to IFN-gamma, the latent cytoplasmic Stat1 (signal transducer and activator of transcription) proteins translocate into the nucleus and activate transcription. We showed previously that Stat1 recruits a group of nuclear proteins, among them MCM5 (minichromosome maintenance) and MCM3, for transcription activation. MCM5 directly interacts with the transcription activation domain (TAD) of Stat1 and enhances Stat1-mediated transcription activation. In this report, we identified two specific residues (R732, K734) in MCM5 that are required for the direct interaction between Stat1 and MCM5 both in vitro and in vivo. MCM5 containing mutations of R732/K734 did not enhance Stat1-mediated transcription activation in response to IFN-gamma. In addition, it also failed to form complexes with other MCM proteins in vivo, suggesting that these two residues may be important for an interaction domain in MCM5. Furthermore, MCM5 bearing mutations in its ATPase and helicase domains did not enhance Stat1 activity. In vitro binding assays indicate that MCM3 does not interact directly with Stat1, suggesting that the presence of MCM3 in the group of Stat1TAD-interacting proteins is due to the association of MCM3 with MCM5. Finally, gel filtration analyses of nuclear extracts from INF-gamma-treated cells demonstrate that there is a MCM5/3 subcomplex coeluting with Stat1. Together, these results strongly suggest that Stat1 recruits a MCM5/3 subcomplex through direct interaction with MCM5 in the process of IFN-gamma-induced gene activation.

Enhanced visibility of hydrogen atoms by neutron crystallography on fully deuterated myoglobin

Although hydrogens comprise half of the atoms in a protein molecule and are of great importance chemically and structurally, direct visualization of them by using crystallography is difficult. Neutron crystallography is capable of directly revealing the position of hydrogens, but its use on unlabeled samples faces certain technical difficulties: the large incoherent scattering of hydrogen results in background scattering that greatly reduces the signal to noise of the experiment. Moreover, whereas the scattering lengths of C, N, and O are positive, that of hydrogen is negative and about half the magnitude. This results in density for hydrogens being half as strong and close to the threshold of detection at 2.0-A resolution. Also, because of its opposite sign, there is a partial cancellation of the hydrogen density with that from neighboring atoms, which can lead to ambiguities in interpretation at medium resolution. These difficulties can be overcome by the use of deuterated protein, and we present here a neutron structure of fully deuterated myoglobin. The structure reveals a wealth of chemical information about the molecule, including the geometry of hydrogen bonding, states of protonation of histidines, and the location and geometry of water molecules at the surface of the protein. The structure also should be of broader interest because it will serve as a benchmark for molecular dynamics and energy minimization calculations and for comparison with NMR studies.

Immunohistochemical study of annexin V expression in placentae of preeclampsia

We investigated the clinical significance of annexin V in the placentae with preeclampsia and found: (1) annexin V was detected on trophoblasts in the placentae and the staining intensity of annexin V in the placentae from such patients was reduced when compared to normal placentae; (2) as expression of annexin V was reduced, the gestosis index from patients with preeclampsia was elevated and the standard deviation value in the infant's standard weight was decreased; plasma level of the fibrin degradation products and thrombin-antithrombin III complex from patients were elevated as the expression of anexin V was reduced. These results suggest that the reduced expression of annexin V in the placentae from patients with preeclampsia may lead to a hypercoagulable state in the intervillous space and may be associated with the development of intrauterine growth restriction.

Annexin V inhibits phosphatidylserine-induced intrauterine growth restriction in mice

To investigate the role of phosphatidylserine (PS) derived from the activated platelets in placental circulation, we established an artificial PS-induced intrauterine growth restriction (IUGR) model in mice and examined whether annexin V, a PS-binding anticoagulant protein, could prevent the development of IUGR in the animal experiments. The ICR mice were injected in the tail vein on days 8, 11 and 14 of pregnancy with filtered PS/phosphatidylcholine (PC) microvesicles (<0.3 microm in maximal diameter). The microvesicles have a procoagulant activity which was inhibited by annexin V in a dose-dependent fashion. The mice were killed on day 18 of pregnancy and the placental and fetal weights were measured. The placental tissue specimens were examined microscopically. PS/PC vesicles induced significant reductions in fetal weights compared with PC vesicles alone. The placental tissue revealed severe congestion with fibrin depositions although the lung and kidney tissue specimens showed minimal histological changes. PS/PC microvesicles with recombinant annexin V showed no significant reductions in fetal weights in mice with PS/PC vesicles alone. These results suggest that PS from the activated platelets induces IUGR by enhancing the coagulation cascade in the placental circulation and that annexin V from the villous trophoblast prevents the development of IUGR.

Combined radiofrequency ablation-cooling catheter for reversible cryothermal mapping and ablation

Reversible cryothermal mapping of cardiac arrhythmias has been performed intraoperatively. However, a steerable cooling catheter for reversible mapping has not yet been developed. We therefore developed and tested a cooling system consisting of a -15 degrees C hypertonic saline reservoir and a 7F steerable catheter also capable of radiofrequency (RF) ablation. Using excised ovine hearts placed in a 37 degrees C circulating saline bath, we measured the temperatures at depths of 0 mm, 1 mm, and 2 mm. The temperature after 90 seconds of cooling was 16.5 +/- 2.1 degrees C at 0 mm compared to 23.9 +/- 4.1 degrees C at 1 mm and 31.1 +/- 3.9 degrees C at 2 mm depth (p < 0.01). These data suggest that a 7F steerable combined RF ablation-cooling catheter may achieve temperatures suitable for mapping arrhythmias such as atrial tachycardias and right ventricular outflow tract tachycardias. Further enhancements to achieve lower temperatures at depth may be needed to reversibly map other arrhythmias such as left ventricular tachycardias.

Histone-like transcription factors in eukaryotes

Histone proteins have long been recognized as important regulators of eukaryotic gene expression. Condensation of DNA into chromatin by the core (H2A, H2B, H3, H4) and linker (H1, H5) histones effectively represses transcription initiation from the promoters of genes that have been packaged. Recently, eukaryotic transcriptional activators and coactivators (both positive and negative) resembling core and linker histone proteins have been discovered. Substantial progress has been made on structural and mechanistic studies of histones and histone-like transcription factors. Three-dimensional structures solved include the core histone octamer, an archael histone homodimer, two core histone-like subunits of transcription factor IID, a linker histone, and a linker histone-like transcriptional activator.