Effectiveness of ultrasonic measurement for the hyomental distance and distance from skin to epiglottis in predicting difficult laryngoscopy in children.

OBJECTIVES: Studies have shown that some ultrasonic indicators can predict difficult airways in adults to an extent. However, whether ultrasonic parameters can be used to predict difficult airways in children is unclear. This study investigated the predictive value of several ultrasonic indices for difficult laryngoscopy (DL) in children. METHODS: Pediatric patients aged 5 to 12 years who underwent endotracheal intubation under general anesthesia were enrolled. The hyomental distance in the extended position (HMDE), tongue thickness, midsagittal tongue cross-sectional area, tongue width, and distance from skin to epiglottis (DSE) were measured by ultrasound before anesthesia. The study end point was DL. The receiver operating characteristic curve was used to evaluate the predictive value of each parameter. RESULTS: Three hundred and ten children were included in the final analysis, and fifteen (4.8%) children had DL. The shortened HMDE assessed by ultrasound could help identify children aged 5 to 12 years with DL (5-8 years: area under the curve (AUC) 0.74, sensitivity 0.88, specificity 0.60; 9-12 years: AUC 0.72, sensitivity 0.71, specificity 0.83). An increased DSE could help identify children aged 5 to 8 years with DL (AUC 0.76, sensitivity 0.88, specificity 0.69). CONCLUSIONS: Ultrasonic measurement of the HMDE can be used to predict DL in children aged 5 to 12 years. The DSE measured by ultrasound can be used to predict DL in children aged 5 to 8 years. CLINICAL RELEVANCE STATEMENT: The hyomental distance and the distance from skin to epiglottis measured by ultrasound can be used to predict difficult laryngoscopy in children, which can help reduce serious complications caused by unanticipated difficult airways in children during anesthesia. KEY POINTS: • Ultrasonic measurement of the hyomental distance in the extended position may be an effective predictor of difficult laryngoscopy in children aged 5 to 12 years. • The distance from skin to epiglottis measured by ultrasound can be used to predict difficult laryngoscopy in children aged 5 to 8 years. • Preoperative airway assessment using ultrasound can be effectively applied in children and has a great application prospect.

Perioperative outcomes in different anesthesia techniques for patients undergoing hip fracture surgery: a systematic review and meta-analysis.

BACKGROUND: Previous studies of the perioperative effects of general and regional anesthesia in adult patients undergoing effects of different anesthesia techniques on patients undergoing hip fracture surgery have not produced consistent results. The aim of this systematic review and meta-analysis was to compare the hip fracture surgery. METHODS: We performed a systematic review and meta-analysis to compare the effects of general anesthesia with regional anesthesia on in-hospital mortality, 30-day mortality, postoperative pneumonia, and delirium in adult hip fracture patients (≥ 18 years). Between January 1, 2022, and March 31, 2023, a systematic search was performed for retrospective observational and prospective randomized controlled studies in PubMed, Ovid Medline, Cochrane Library, and Scopus. RESULTS: Twenty-one studies including 363,470 patients showed higher in-hospital mortality in the general anesthesia group compared with regional anesthesia (OR = 1.21; 95% CI 1.13-1.29; P < 0.001, n = 191,511). The 30-day mortality (OR = 1.00; 95% CI 0.96-1.05; P = 0.95, n = 163,811), the incidence of postoperative pneumonia (OR = 0.93; 95% CI 0.82-1.06; P = 0.28, n = 36,743) and the occurrence of postoperative delirium in the two groups (OR = 0.94; 95% CI 0.74-1.20; P = 0.61, n = 2861) had no significant difference. CONCLUSION: Regional anesthesia is associated with reduced in-hospital mortality. However, the type of anesthesia did not affect the occurrence of 30-day mortality, postoperative pneumonia, and delirium. A large number of randomized studies are needed in the future to examine the relationship between type of anesthesia, postoperative complications, and mortality.

Real-Time Ultrasound-Guided Versus Ultrasound-Assisted Spinal Anesthesia in Elderly Patients With Hip Fractures: A Randomized Controlled Trial.

BACKGROUND: Traditional landmark-guided spinal anesthesia can be challenging in elderly patients with hip fractures. Ultrasound assistance (USAS) and real-time ultrasound guidance (USRTG) techniques can facilitate lumbar neuraxial blocks. However, it remains undetermined which method is optimal for use in elderly patients. This study aimed to evaluate which technique was associated with a higher success rate of spinal anesthesia in elderly patients with hip fractures: USAS or USRTG technique. METHODS: A total of 114 elderly patients (≥70 years of age) with hip fractures were randomly assigned to receive spinal anesthesia using either the USAS or USRTG technique. The primary outcome was the first-attempt success rate, analyzed using the χ2 test. Secondary outcomes included first-pass success rate, the number of needle attempts and passes, locating time, procedure time, total time, adverse reactions and complications, patient satisfaction, and procedural difficulty score. RESULTS: The first-attempt success rate (80.7% vs 52.6%; 95% confidence interval [CI], for the difference, 11.6-44.6) and first-pass success rate (63.2% vs 31.6%; 95% CI for the difference, 14.2-49) were both significantly higher in the USAS compared with the USRTG group (both P = .001). The number of attempts (1 [1-1] vs 1 [1-3]; P = .001) and median passes (1 vs 3; P < .001) were both significantly lower in the USAS group than in the USRTG group. The USRTG group had a shorter locating time (175 seconds [129-234 seconds] vs 315 seconds [250-390 seconds]; P < .001) but a longer procedure time (488 seconds [260-972 seconds] vs 200 seconds [127-328 seconds]; P < .001) and total time (694 seconds [421-1133 seconds] vs 540 seconds [432-641 seconds]; P = .036). There were no significant differences between the 2 groups with regard to the adverse reactions and complications. More patients in the USAS group had a high satisfaction score of 3 to 5 (P = .008). Overall, anesthesiologists rated the USRTG group procedure as "more difficult" (P = .008). CONCLUSIONS: In elderly patients with hip fractures, spinal anesthesia with the USRTG technique is not superior to the USAS technique since it has a lower success rate, longer procedure time, lower satisfaction score, and is more difficult to perform. So USAS technique may be more suitable for elderly patients.

Is gabapentin effective and safe in the treatment of chronic pelvic pain in women: a systematic review and meta-analysis.

INTRODUCTION AND HYPOTHESIS: Chronic pelvic pain (CPP) affects 2.1-24% of women, causing physical and psychological damage to women around the world. Based on the efficacy of gabapentin in the treatment of chronic pain, we conducted this study to evaluate the efficacy and safety of gabapentin in reducing pain in women with CPP. METHODS: Systematic searches were performed in the electronic databases of PubMed, Embase, Web of Science, Scopus, Cochrane, and Clinicalkey databases. Studies focused on comparing the efficacy of gabapentin and placebo in the treatment of female CPP patients were included. RevMan 5.4 was used to analyze the results and risk of bias. Two investigators independently selected eligible studies and extracted related pain scores and side effects for meta-analysis. RESULTS: In total, 4 RCTs were enrolled in the meta-analysis, totaling 425 patients. Among patients receiving gabapentin, the average pain scores in 3 and 6 months were significantly lower than those in the placebo group(p < 0.00001). The results showed that there was no statistical difference between gabapentin and placebo in the reduction of pain scores from baseline(p = 0.41). The incidence of side effects in the gabapentin group was significantly higher than that in the placebo group (p < 0.00001). CONCLUSION: This systematic review and meta-analysis demonstrated that for women with CPP, gabapentin was significantly different from placebo in average pain scores at 3 and 6 months. However, the two drugs did not differ in the reduction in pain scores from baseline. Gabapentin can bring more significant side effects, whether they are common side effects or serious side effects.

Perioperative transcutaneous electrical acupoint stimulation (pTEAS) in pain management in major spinal surgery patients.

BACKGROUND: Lumbar disc herniation is seen in 5-15% of patients with lumbar back pain and is the most common spine disorder demanding surgical correction. Spinal surgery is one of the most effective management for these patients. However, current surgical techniques still present complications such as chronic pain in 10-40% of all patients who underwent lumbar surgery, which has a significant impact on patients' quality of life. Research studies have shown that transcutaneous electrical acupoint stimulation (TEAS) may reduce the cumulative dosage of intraoperative anesthetics as well as postoperative pain medications in these patients. OBJECTIVE: To investigate the effect of pTEAS on pain management and clinical outcome in major spinal surgery patients. METHODS: We conducted a prospective, randomized, double-blind study to verify the effect of pTEAS in improving pain management and clinical outcome after major spinal surgery. Patients (n = 90) who underwent posterior lumbar fusion surgery were randomized into two groups: pTEAS, (n = 45) and Control (n = 45). The pTEAS group received stimulation on acupoints Zusanli (ST.36), Sanyinjiao (SP.6), Taichong (LR.3), and Neiguan (PC.6). The Control group received the same electrode placement but with no electrical output. Postoperative pain scores, intraoperative outcome, perioperative hemodynamics, postoperative nausea and vomiting (PONV), and dizziness were recorded. RESULTS: Intraoperative outcomes of pTEAS group compared with Control: consumption of remifentanil was significantly lower (P < 0.05); heart rate was significantly lower at the end of the operation and after tracheal extubation (P < 0.05); and there was lesser blood loss (P < 0.05). Postoperative outcomes: lower pain visual analogue scale (VAS) score during the first two days after surgery (P < 0.05); and a significantly lower rate of PONV (on postoperative Day-5) and dizziness (on postoperative Day-1 and Day-5) (P < 0.05). CONCLUSION: pTEAS could manage pain effectively and improve clinical outcomes. It could be used as a complementary technique for short-term pain management, especially in patients undergoing major surgeries. TRIAL REGISTRATION: ChiCTR1800014634, retrospectively registered on 25/01/2018. http://medresman.org/uc/projectsh/projectedit.aspx?proj=183.

Emergency tracheal intubation in 202 patients with COVID-19 in Wuhan, China: lessons learnt and international expert recommendations.

Tracheal intubation in coronavirus disease 2019 (COVID-19) patients creates a risk to physiologically compromised patients and to attending healthcare providers. Clinical information on airway management and expert recommendations in these patients are urgently needed. By analysing a two-centre retrospective observational case series from Wuhan, China, a panel of international airway management experts discussed the results and formulated consensus recommendations for the management of tracheal intubation in COVID-19 patients. Of 202 COVID-19 patients undergoing emergency tracheal intubation, most were males (n=136; 67.3%) and aged 65 yr or more (n=128; 63.4%). Most patients (n=152; 75.2%) were hypoxaemic (Sao2 <90%) before intubation. Personal protective equipment was worn by all intubating healthcare workers. Rapid sequence induction (RSI) or modified RSI was used with an intubation success rate of 89.1% on the first attempt and 100% overall. Hypoxaemia (Sao2 <90%) was common during intubation (n=148; 73.3%). Hypotension (arterial pressure <90/60 mm Hg) occurred in 36 (17.8%) patients during and 45 (22.3%) after intubation with cardiac arrest in four (2.0%). Pneumothorax occurred in 12 (5.9%) patients and death within 24 h in 21 (10.4%). Up to 14 days post-procedure, there was no evidence of cross infection in the anaesthesiologists who intubated the COVID-19 patients. Based on clinical information and expert recommendation, we propose detailed planning, strategy, and methods for tracheal intubation in COVID-19 patients.

Propofol affects mouse embryonic fibroblast survival and proliferation in vitro via ATG5- and calcium-dependent regulation of autophagy.

Propofol is a commonly used intravenous anesthetic agent, which has been found to affect cell survival and proliferation especially in early life. Our previous studies show that propofol-induced neurodegeneration and neurogenesis are closely associated with cell autophagy. In the present study we explored the roles of autophagy-related gene 5 (ATG5) in propofol-induced autophagy in mouse embryonic fibroblasts (MEF) in vitro. We showed that ATG5 was functionally related to propofol-induced cell survival and damage: propofol significantly enhanced cell survival and proliferation at a clinically relevant dose (10 µM), but caused cell death at an extremely high concentration (200 µM) in ATG5-/- MEF, but not in WT cells. The dual effects found in ATG5-/- MEF could be blocked by intracellular Ca2+ channel antagonists. We also found that propofol evoked a moderate (promote cell growth) and extremely high (cause apoptosis) cytosolic Ca2+ elevation at the concentrations of 10 µM and 200 µM, respectively, only in ATG5-/- MEF. In addition, ATG5-/- MEF themselves released more Ca2+ in cytosolic space and endoplasmic reticulum compared with WT cells, suggesting that autophagy deficiency made intracellular calcium signaling more vulnerable to external stimuli (propofol). Altogether, our results reveal that ATG5 plays a crucial role in propofol regulation of cell survival and proliferation by affecting intracellular Ca2+ homeostasis.

Landmark-guided versus modified ultrasound-assisted Paramedian techniques in combined spinal-epidural anesthesia for elderly patients with hip fractures: a randomized controlled trial.

BACKGROUND: Combined spinal-epidural (CSE) anesthesia is considerably challenging for elderly patients with hip fractures due to spine degeneration and limitations in positioning. This study aimed to investigate the ability of a modified preprocedural ultrasound-guided technique to improve the success rate and efficacy of CSE anesthesia for elderly patients with hip fractures. METHODS: This prospective, single-blinded, parallel-group randomized controlled trial included 80 patients (aged ≥65 years) who were scheduled for elective hip fracture surgery with CSE anesthesia. Patients were randomly allocated into landmark group (n = 40) or the ultrasound group (n = 40). The primary outcome was first-pass success rate. Secondary outcomes included first-attempt success rate; number of needle insertion attempts; number of needle passes; locating, puncture, and total time; level of block; procedural adverse reactions and postoperative complications; and patient satisfaction score. Patients were blinded to group allocation. RESULTS: Eighty patients completed the study and were included in the final analysis. The first-pass success rates for the landmark and ultrasound groups were 20 and 70%, respectively (P < 0.001). The first-attempt success rates in the landmark and ultrasound groups were 42.5 and 85%, respectively (P < 0.001). The median number of attempts was lower in ultrasound-assisted group (1 [1]) than landmark-guided group (2 [1, 2]), P < 0.001). The median number of needle passes was lower in ultrasound group (1 [1, 2]) than in landmark-guided group (3 [2, 4], P < 0.001). The locating time (P < 0.001) and total time (P = 0.001) were longer in the ultrasound group, while puncture time was shorter (P = 0.003). No significant difference was found regarding the incidence of adverse reactions and complications. More patients in the ultrasound group had a high satisfaction score of 4-5 (P = 0.007). Interestingly, subgroup analysis demonstrated benefits for ultrasound in patients with scoliosis. CONCLUSIONS: Modified ultrasound-assisted CSE anesthesia increases first-pass and first-attempt success rates, and reduces needle insertion attempts, passes, and puncture time for elderly patients with hip fracture, especially those with scoliosis. This technique improves patient satisfaction and warrants consideration for application in clinical practice. TRIAL REGISTRATION: Chinese Clinical Trial Register (identifier, ChiCTR1900020819 ; date of registration, January 20, 2019).

Correction to: Landmark-guided versus modified ultrasound-assisted Paramedian techniques in combined spinal-epidural anesthesia for elderly patients with hip fractures: a randomized controlled trial.

An amendment to this paper has been published and can be accessed via the original article.

A single-dose of stellate ganglion block for the prevention of postoperative dysrhythmias in patients undergoing thoracoscopic surgery for cancer: A randomised controlled double-blind trial.

BACKGROUND: New-onset arrhythmias and sleep disturbances are frequently observed during the postoperative period in patients undergoing thoracic surgery. OBJECTIVE: We evaluated the effectiveness of a single-dose stellate ganglion block (SGB) to prevent the occurrence of arrhythmias in patients undergoing thoracic surgery for cancer. DESIGN: Randomised controlled double-blind study. SETTING: Single university hospital. PATIENTS: Ninety patients with lung cancer or oesophagal cancer scheduled for elective video-assisted thoracoscopic surgery were randomly randomised into one of two equal groups (the SGB group and control group, n = 40 each). INTERVENTIONS: Patients received a single dose of 5 ml of 0.5% ropivacaine during ultrasound-guided SGB before induction of general anaesthesia in the SGB group. MAIN OUTCOME MEASURES: Holter ECG was continuously monitored during the first 48 postoperative hours, and sleep state was monitored during the first two postoperative nights. RESULTS: The incidences of postoperative supraventricular tachycardias were lower in the SGB group compared with the control group during the first 48 postoperative hours; 11.6 (5/43) vs. 31.8% (14/44), respectively, P = 0.023 (odds ratio 0.28, 95% confidence interval 0.09 to 0.87). The SGB also prolonged the total sleep time and increased the sleep efficiency during the first two postoperative nights. The duration of stage N2 sleep was longer in the SGB group compared with the control group [28 (interquartile range, 14 to 58) to 94 (interquartile range, 69 to 113) min, P = 0.016] on the first postoperative night. There were no differences in the duration of stage N1 and N3 sleep (P = 0.180, 0.086, respectively) on the first postoperative night, and the duration of stage N1, N2 and N3 sleep (P = 0.194, 0.057, 0.405, respectively) on the second postoperative night between the groups. CONCLUSION: A pre-operative SGB effectively prevented the occurrence of postoperative supraventricular tachycardias and improves the objective sleep quality in patients undergoing thoracic surgery for cancer. TRIAL REGISTRATION NUMBER: ChiCTR-1900023064.

Expert Recommendations for Tracheal Intubation in Critically ill Patients with Noval Coronavirus Disease 2019.

Coronavirus Disease 2019 (COVID-19), caused by a novel coronavirus (SARS-CoV-2), is a highly contagious disease. It firstly appeared in Wuhan, Hubei province of China in December 2019. During the next two months, it moved rapidly throughout China and spread to multiple countries through infected persons travelling by air. Most of the infected patients have mild symptoms including fever, fatigue and cough. But in severe cases, patients can progress rapidly and develop to the acute respiratory distress syndrome, septic shock, metabolic acidosis and coagulopathy. The new coronavirus was reported to spread via droplets, contact and natural aerosols from human-to-human. Therefore, high-risk aerosol-producing procedures such as endotracheal intubation may put the anesthesiologists at high risk of nosocomial infections. In fact, SARS-CoV-2 infection of anesthesiologists after endotracheal intubation for confirmed COVID-19 patients have been reported in hospitals in Wuhan. The expert panel of airway management in Chinese Society of Anaesthesiology has deliberated and drafted this recommendation, by which we hope to guide the performance of endotracheal intubation by frontline anesthesiologists and critical care physicians. During the airway management, enhanced droplet/airborne PPE should be applied to the health care providers. A good airway assessment before airway intervention is of vital importance. For patients with normal airway, awake intubation should be avoided and modified rapid sequence induction is strongly recommended. Sufficient muscle relaxant should be assured before intubation. For patients with difficult airway, good preparation of airway devices and detailed intubation plans should be made.

Ultrasound-guided phrenic nerve block for intraoperative persistent hiccups: a case report.

BACKGROUND: Continuous hiccups during surgery not only affect the surgical procedure, they can also cause adverse effects for the patient. Apart from active investigation of the cause of the hiccups, their timely termination is also necessary. CASE PRESENTATION: We reported a case of a 70-year-old woman with continuous intraoperative hiccups that appeared during vaginal hysterectomy under low continuous epidural anesthesia. After the ineffectiveness CO2 repeated inhalation and intravenous administration of chlorpromazine and methoxychlorpromide, we performed unilateral phrenic nerve block under ultrasound guidance. Hiccups were terminated without any related complications. CONCLUSIONS: During intraoperative continuous hiccups, ultrasound guided phrenic nerve block may be a suitable treatment option when physical methods and drug therapy are not effective. However, given the absence of a vital risk related to hiccups, this block should imply the complete absence of any respiratory contraindication and a prolonged postoperative respiratory monitoring.

A comparison of the incidence of supraventricular arrhythmias between thoracic paravertebral and intercostal nerve blocks in patients undergoing thoracoscopic surgery: A randomised trial.

BACKGROUND: Postoperative supraventricular arrhythmias are common in patients after thoracoscopic lobectomy. Inadequate pain control has long been recognised as a significant risk factor for arrhythmias. The performance of ultrasound-guided (USG) thoracic paravertebral block (PVB) is increasing as an ideal technique for postoperative analgesia. OBJECTIVE: We conducted this study to evaluate whether a single-shot USG thoracic PVB would result in fewer postoperative supraventricular tachycardias (SVT) than intercostal nerve blocks (ICNBs) after thoracoscopic pulmonary resection. DESIGN: A randomised controlled study. SETTING: A single university hospital. PATIENTS: Sixty-eight patients undergoing thoracoscopic lobectomy were randomised into two equal groups of 34. INTERVENTIONS: For postoperative pain control, all patients received a total of 0.3 ml kg of a mixture containing 0.5% ropivacaine and 1/200 000 epinephrine after placement of needles for either a single thoracic PVB or two individual ICNBs, both guided by ultrasound. Data were obtained during the first 48 postoperative hours. MAIN OUTCOME MEASURES: The primary outcome was the incidence of SVT after thoracoscopic pulmonary resection. RESULTS: During the first 48 postoperative hours, the incidences of SVT and atrial fibrillation were lower in the USG thoracic PVB group (14.7 vs. 46.9%, P = 0.004 and 3.0 vs. 18.8%, P = 0.037, respectively). The requirement for ß-receptor blockade was more frequent in the ICNBs group than in the PVB group (5.9 vs. 25%, P = 0.033). CONCLUSION: After placement of the needle using ultrasound guidance, a single-shot thoracic PVB is a well tolerated and effective technique to reduce the incidences of postoperative SVT and atrial fibrillation in patients undergoing thoracoscopic pulmonary resection. TRIAL REGISTRATION: http://www.chictr.org/cn/, registration number: ChiCTR-IOR-17010952.

Anticipated and unanticipated difficult airway management.

PURPOSE OF REVIEW: Management of difficult airway is far from optimal despite of continuous progress in science and technology. The purpose of this review is to summarize the current research in the field and bring readers up to date. RECENT FINDINGS: New technologies for intubation make providers more confident to handle difficult airways, but there is lack of evidence indicating the reduction in incidence of 'cannot intubate cannot ventilate (CICV)'. Optimization of mask ventilation should reduce the incidence of difficult mask ventilation but it is greatly underappreciated. Even optimization of preoxygenation is not directly associated with any decreased incidence of difficult airway, but it prolongs time of safe apnea oxygenation; therefore, is likely to improve the outcome of the patients if CICV occurs. SUMMARY: Improvement of managing difficult airway relies on optimized mask ventilation, utilization of the appropriate tools for intubation, maximization of the safe apnea oxygenation time, prompt surgical airway in response to severe hypoxia in case effective noninvasive interventions are not achievable. It seems that a simplified and concise algorithm of difficult airway management needs to be established in order to enable providers to easily remember and execute.

Tetramethyl Pyrazine Protects Hippocampal Neurons Against Anoxia/Reoxygenation Injury Through Inhibiting Apoptosis Mediated by JNK/MARK Signal Pathway.

BACKGROUND Tetramethyl pyrazine (TMP) is a typical biologically active alkaloid isolated from the Chinese herb Ligusticum walliichi. It has been reported that TMP shows neuroprotective and stroke injury reductive properties in cerebral ischemia/reperfusion (I/R) animal models. In the present study we sought to investigate the effect and potential intervention mechanism of TMP in anoxia/reoxygenation (A/R) rat hippocampal neurons. MATERIAL AND METHODS After being cultured for 7 days, primary hippocampal neurons were randomly assigned into a normal control group (N), a TMP group (C: 0 ug/ml, L: 60 ug/ml, M: 200ug/ml and H: 800 ug/ml), and a JNK inhibitor group (S: SP600125, 10 µmol/L). A hypoxia/reoxygenation model were prepared 1 h after incubation. Hippocampal neurons were incubated in 90% N2 and 10% CO2 for 2 h, and then reoxygenated for 24 h in an incubator with 5%CO2 at the temperature of 37°C. The apoptosis rate, MKK4 and MKK7 mRNA and JNK kinase protein levels (C-fos, c-jun, and P-JNK) of hippocampal neurons were detected. RESULTS The apoptosis rates of hippocampal neurons induced by A/R showed significant reduction after being pre-treated with JNK inhibitor, TMP 60 µg/ml, 200 µg/ml, and 800 µg/ml. The JNK kinase MKK4mRNA and MKK7mRNA levels, as well as the expressions of C-fos, C-jun, and P-JNK protein levels, were also be reduced. CONCLUSIONS TMP may produce a protective effect in anoxia/reoxygenation-induced primary hippocampal neuronal injury by inhibiting the apoptosis of the hippocampal neurons; the possible mechanism may be inhibition of the JNK signal pathway.

Finite element study on the micromechanics of cement-augmented proximal femoral nail anti-rotation (PFNA) for intertrochanteric fracture treatment.

Blade cut-out is a common complication when using proximal femoral nail anti-rotation (PFNA) for the treatment of intertrochanteric fractures. Although cement augmentation has been introduced to overcome the cut-out effect, the micromechanics of this approach remain to be clarified. While previous studies have developed finite element (FE) models based on lab-prepared or cadaveric samples to study the cement-trabeculae interface, their demanding nature and inherent disadvantages limit their application. The aim of this study was to develop a novel 'one-step forming' method for creating a cement-trabeculae interface FE model to investigate its micromechanics in relation to PFNA with cement augmentation. A human femoral head was scanned using micro-computed tomography, and four volume of interest (VOI) trabeculae were segmented. The VOI trabeculae were enclosed within a box to represent the encapsulated region of bone cement using ANSYS software. Tetrahedral meshing was performed with Hypermesh software based on Boolean operation. Finally, four cement-trabeculae interface FE models comprising four interdigitated depths and five FE models comprising different volume fraction were established after element removal. The effects of friction contact, frictionless contact, and bond contact properties between the bone and cement were identified. The maximum micromotion and stress in the interdigitated and loading bones were quantified and compared between the pre- and post-augmentation situations. The differences in micromotion and stress with the three contact methods were minimal. Micromotion and stress decreased as the interdigitation depth increased. Stress in the proximal interdigitated bone showed a correlation with the bone volume fraction (R2 = 0.70); both micromotion (R2 = 0.61) and stress (R2 = 0.93) at the most proximal loading region exhibited a similar correlation tendency. When comparing the post- and pre-augmentation situations, micromotion reduction in the interdigitated bone was more effective than stress reduction, particularly near the cement border. The cementation resulted in a significant reduction in micromotion within the loading bone, while the decrease in stress was minimal. Noticeable gradients of displacement and stress reduction can be observed in models with lower bone volume fraction (BV/TV). In summary, cement augmentation is more effective at reducing micromotion rather than stress. Furthermore, the reinforcing impact of bone cement is particularly prominent in cases with a low BV/TV. The utilization of bone cement may contribute to the stabilization of trabecular bone and PFNA primarily by constraining micromotion and partially shielding stress.

Mitochondria protective and anti-apoptotic effects of peripheral benzodiazepine receptor and its ligands on the treatment of asthma in vitro and vivo.

BACKGROUND: Asthma is a prevalent respiratory inflammatory disease. Abnormal apoptosis of bronchial epithelial cells is one of the major factors in the progression of asthma. Peripheral benzodiazepine receptors are highly expressed in bronchial epithelial cells, which act as a component of the mitochondrial permeability transition pore to regulate its opening and closing and apoptosis of bronchial epithelial cells. We aimed to investigate the mechanisms by which peripheral benzodiazepine receptor and its ligands, agonist 4'-Chlorodiazepam (Ro5-4864) and antagonist 1-(2-chlorophenyl)-N-methyl-N-(1-methylpropyl)-3-isoquinolinecarboxamide (PK 11,195), modulate the mitochondrial function and cell apoptosis in the treatment of asthma. METHODS: In vitro study, Ro5-4864 and PK 11,195 were utilized to pretreat cells prior to the inflammatory injury induced by Lipopolysaccharide. The reactive oxygen species, the apoptosis of cell, the mitochondrial membrane potentials, the ultrastructures of the mitochondria and the expression levels of peripheral benzodiazepine receptors and apoptosis-related proteins and genes were detected. In vivo study, mice were administrated intraperitoneally with Ro5-4864 and PK 11,195 before sensitized and challenged by ovalbumin. Serum IgE and bronchoalveolar lavage fluid cytokines were detected, and lung tissues were underwent the histopathological examination. RESULTS: The ligands of peripheral benzodiazepine receptor counteracted the effects of the increase of reactive oxygen species, the elevated extent of apoptosis, the decrease of mitochondrial membrane potentials and the disruption of mitochondrial ultrastructures induced by Lipopolysaccharide. The ligands also promoted the expression of anti-apoptosis-related proteins and genes and inhibited the expression of pro-apoptosis-related proteins and genes. Besides, the ligands reduced the levels of serum IgE and bronchoalveolar lavage fluid cytokines in asthmatic mice and attenuated the histopathological damage of lungs. CONCLUSION: Peripheral benzodiazepine receptor serves as a potential therapeutic target for the treatment of asthma, with its ligands exerting mitochondrial protective and anti-apoptotic effects on bronchial epithelial cells.