[Regulation of colony-stimulating factor 1 receptor inhibitor pexidartinib on the senescence of mouse bone marrow-derived macrophages stimulated by lipopolysaccharide]

Objective: To investigate the effects of colony-stimulating factor 1 receptor (CSF-1R) inhibitor pexidartinib (PLX3397) on the senescence of bone marrow-derived macrophages (BMDM) stimulated by lipopolysaccharide (LPS). Methods: BMDM were isolated and cultured from femurs and tibiae of 10 male C57BL/6 mice aged 6-8 weeks (obtained from Laboratory Animal Center of Guizhou Medical University). They were divided into blank control group, LPS group (treated with 1 μg/ml LPS for 24 h) as well as low, medium and high concentration PLX3397 pretreatment groups (treated with 100, 500 and 1 000 nmol/L PLX3397 for 4 h respectively followed by 1 μg/ml LPS for 24 h). The corresponding markers of macrophages were detected by flow cytometry. Cell viability was detected by cell counting kit-8 and cellular senescence was detected by senescence-associated-β-galactosidase (SA-β-gal) staining. Meanwhile, protein expressions of cycle-dependent kinase inhibitor p16, p21 and CSF-1R were detected by Western blotting, and the expressions of p16 and p21 were detected by intracellular immunofluorescence. Real-time fluorescence quantitative PCR (RT-qPCR) was used to investigate the mRNA levels of senescence-associated secretory phenotype (SASP) genes including interleukin (IL), IL-1β, chemokine-1/10 (CXCL-1/10), matrix metalloproteinase-8 (MMP-8), and transforming growth factor-β (TGF-β). Results: The rate of SA-β-gal positive staining in medium and high concentration PLX3397 pretreatment groups [(39.33±4.93)% and (36.33±3.06)% respectively] were significantly downregulated compared with LPS group [(52.00±3.00)%] (P=0.020, P=0.005). The expression of CSF-1R protein in low, medium and high concentration PLX3397 pretreatment groups were (0.74±0.18, 0.61±0.07, 0.54±0.06), all of which were significantly lower than that in LPS group (1.16±0.08) (P=0.013, P=0.002, P<0.001). The expression levels of CSF-1R mRNA in low, medium and high concentration PLX3397 pretreatment groups (1.04±0.06, 0.90±0.05, 1.18±0.08) showed similar trend (2.90±0.25) (P<0.001). The average fluorescence intensity of p16 in all PLX3397 pretreatment groups were 49.76±3.65, 48.21±1.72, 47.99±1.26 respectively, which were significantly lower than that in LPS group (66.88±5.85) (P=0.001, P<0.001, P<0.001). The average fluorescence intensity of p21 in medium and high concentration PLX3397 pretreatment groups were (34.43±3.62, 30.13±0.86), significantly lower than that in LPS group (46.82±5.33) (P=0.043, P=0.007). The expression of p16 protein in low, medium and high concentration PLX3397 pretreatment groups (0.56±0.04, 0.55±0.04, 0.35±0.19) were significantly lower than that in LPS group (0.98±0.10) (P=0.003, P=0.002, P<0.001), as well the expression of p21 protein (0.69±0.20, 0.42±0.08, 0.26±0.14) (P=0.032, P=0.002, P<0.001). According to the results of RT-qPCR, the expressions of IL-6, IL-1β, CXCL-1, CXCL-10 and MMP-8 in PLX3397 pretreatment groups were significantly lower than those in LPS group (P<0.001), while the expression of TGF-β increased (P<0.001). Conclusions: LPS could induce the cell senescence, increase the secretion of SASP and aggravate local inflammation by activating the CSF-1R on the cell surface of bone marrow-derived macrophages. CSF-1R inhibitor PLX3397 might attenuate CSF-1R activation associated with LPS and inhibit the senescence of bone marrow-derived macrophages induced by LPS.

Small residual fracture gaps delay time to union in length stable femur fractures treated with intrameduallary fixation

OBJECTIVES

The purpose of this study was to investigate whether residual fracture gapping and translation at time of intramedullary nail (IMN) fixation for diaphyseal femur fractures were associated with delayed healing or nonunion.

DESIGN

Retrospective cohort study SETTING: Level 1 trauma hospital, quaternary referral center PATIENTS/PARTICIPANTS/INTERVENTION: Length stable Winquist type 1 and 2 diaphyseal femur fractures treated with IMN at a single Level I trauma center were retrospectively reviewed.

MAIN OUTCOME MEASURE

The largest fracture gap and translation were evaluated on immediate anteroposterior (AP) and lateral postoperative radiographs. Radiographic healing was assessed using Radiographic Union Score in Femur (RUSF) scores at each follow-up. Radiographic union was defined as a RUSF score ≥8 and consolidation of at least 3 cortices. ANOVA and student's t-tests were used to evaluate the influence of fracture gap parameters on time to union (TTU) and nonunion rate. Patients were stratified to measured average gap and translation distances <1mm, 1-3mm and >3mm for portions of the analysis.

RESULTS

Sixty-six patients who underwent IMN with adequate follow-up were identified. A total of 93.9% of patients achieved union at an average of 2.8 months. Fractures with average AP/lateral gaps of <1mm, 1-2.9 mm, and >3mm had an average TTU of 70.1, 91.7, and 111.9 days respectively; fractures with larger residual gap sizes had a significantly longer TTU (p=0.009). Fractures with an average gap of 1-2.9mm and >3 mm had a significantly higher nonunion rate (1.5% and 4.5% respectively) compared to 0% nonunion in the <1 mm group (p=0.003).

CONCLUSION

Residual gapping following intramedullary fixation of length stable diaphyseal femur fractures is associated with a significant increase in likelihood of nonunion.

SUMMARY

Residual displacement of length stable femoral shaft fractures following intramedullary nailing can have a significantly negative impact on fracture healing. An average 3 mm AP/lateral residual fracture gap or a total of 6 mm of the AP + lateral fracture gap appeared to be a critical gap size with increased rates of nonunion and time to union. Therefore, we suggest minimizing the sum of the residual AP and lateral fracture gap to less than a total of 6 mm.

Hook of Hamate Fractures

Hook of hamate fractures are uncommon injuries with unclear prevalence. Classic presenting symptoms include volar-ulnar hand/wrist pain and weakness in grip, with possible ulnar nerve paresthesias. Patient factors, such as activity level and desired return to work/sport, shape the most appropriate treatment regimen although excision of the hook has been adopted by most surgeons. Overall, once patients receive the correct diagnosis and are treated, good outcomes with high satisfaction rates are expected.

Indirect Cost of Traumatic Brachial Plexus Injuries in the United States

BACKGROUND

Traumatic brachial plexus injuries (BPIs) disproportionately affect young, able-bodied individuals. Beyond direct costs associated with medical treatment, there are far-reaching indirect costs related to disability and lost productivity. Our objective was to estimate per-patient indirect cost associated with BPI.

METHODS

We estimated indirect costs as the sum of (1) short-term wage loss, (2) long-term wage loss, and (3) disability payments. Short-term (6-month) wage loss was the product of missed work days and the average earnings per day. The probability of return to work was derived from a systematic review of the literature, and long-term wage loss and disability payments were estimated. Monte Carlo simulation was used to perform a sensitivity analysis of long-term wage loss by varying age, sex, and return to work simultaneously. Disability benefits were estimated from U.S. Social Security Administration data. All cost estimates are in 2018 U.S. dollars.

RESULTS

A systematic review of the literature demonstrated that the patients with BPI had a mean age of 26.4 years, 90.5% were male, and manual labor was the most represented occupation. On the basis on these demographics, our base case was a 26-year-old American man working as a manual laborer prior to BPI, with an annual wage of $36,590. Monte Carlo simulation estimated a short-term wage loss of $22,740, a long-term wage loss of $737,551, and disability benefits of $353,671. The mean total indirect cost of traumatic BPI in the Monte Carlo simulations was $1,113,962 per patient over the post-injury lifetime (median: $801,723, interquartile range: $22,740 to $2,350,979). If the probability of the patient returning to work at a different, lower-paying job was doubled, the per-patient total indirect cost was $867,987.

CONCLUSIONS

BPI can have a far-reaching economic impact on both individuals and society. If surgical reconstruction enables patients with a BPI to return to work, the indirect cost of this injury decreases.

LEVEL OF EVIDENCE

Economic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Phototaxis of Grapholitha molesta (Lepidoptera: Olethreutidae) to Different Light Sources

The Oriental Fruit Moth Grapholita molesta (Busck) causes substantial damage to stone and pome fruit crops worldwide. Light-based traps offer a potential means for pest monitoring and management. In this study, we tested the preference of G. molesta for the following light sources: monochromatic light produced from light-emitting diodes (LEDs) (red, orange, yellow, green, blue, violet, and white), specific wavelengths of light produced from filters (405, 450, 480, 512, 540, 576, and 610 nm), and polychromatic light produced by different numbers (0, 12, 24, and 36) of green, blue, and violet LEDs. The arrangement of polychromatic lights was based on an orthogonal design matrix of L16 (4(3)). Based on the results of former studies, we further determined the optimal number of green and violet LEDs. The results showed that: 1) G. molesta strongly preferred the green, violet, and blue LEDs; 2) G. molesta significantly preferred light at 405 nm, followed by 540 nm, and showed no phototaxis to 480 nm; 3) for the polychromatic light configuration, violet and green were the factors that determined the preference of G. molesta, and the lamp with 12 violet LEDs captured the most moths; and 4) for the lamps with different light intensities, 36 violet LEDs or 12 green LEDs attracted the most moths, with the former performing better.

Amputee locomotion: determining the inertial properties of running-specific prostheses

OBJECTIVES

(1) To test the validity of a trifilar pendulum in estimating moments of inertia (MOIs) for running-specific prostheses (RSPs), (2) to measure inertial properties (mass, center of mass [CM] position, and MOIs) for 4 RSPs, (3) to verify the influence of the stiffness on the inertial properties of RSPs, and (4) to develop a predictive equation to estimate RSP CM positions.

DESIGN

An aluminum block with known MOIs was used for verifying the accuracy of the trifilar pendulum MOI measurements. MOI errors were investigated by systematically misaligning the block and pendulum principal axes across a range of 1 to 10cm. Mass, CM position, and MOI were tested across 4 RSP designs with 3 stiffness categories each.

SETTING

University biomechanics laboratory.

SPECIMENS

Four different RSP designs and 3 stiffness categories per design were examined.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

MOI errors from known values and principal axis misalignments between RSPs and pendulum; mass, CM positions, and RSP principal axis MOIs; and predictive equation CM position errors.

RESULTS

The trifilar pendulum estimated MOIs within -6.21×10(-5)kg/m(2) (≤1% error) for a block with known MOIs. Misalignments of 1 to 5cm between the RSPs' and pendulum's CM yielded errors from .00002 to .00113 kg/m(2) (0.3%-59.2%). Each RSP's inertial properties are presented. MOIs about any axis varied <.004kg/m(2) across stiffness categories; MOIs differed up to .013kg/m(2) between different designs. The predictive CM equation erred between .010 and .028m when using average input values across an RSP design.

CONCLUSIONS

Trifilar pendulums can accurately measure RSP MOI. The RSP inertial properties differed slightly across stiffness categories within each design, but differed more substantially across different RSP designs. Using a predictive equation to estimate RSP CM positions can provide adequate data, but directly measuring CM positions is preferable.

[Clinical study of the sentinel lymph node of patients with laryngeal and hypopharyngeal carcinomas]

OBJECTIVE

To investigate the methods of detecting the sentinel lymph node of laryngeal and hypopharyngeal carcinomas and its predictive value in the cervical metastasis of the carcinoma.

METHODS

In 29 patients who suffered from laryngeal or hypopharyngeal carcinoma with NO neck, the patent blue was injected into the surrounding tissue of the tumor during the operation to identify the sentinel lymph nodes. The sentinel lymph nodes were dyed blue. The frozen histopathology was done during the operation, the lymph nodes at the ipsilateral side of the neck were dissected completely, and the routine histopathology was done as the gold standard to study the predictive value of the sentinel lymph node in the metastasis of the cervical node.

RESULTS

Of 29 patients, 28 patients' sentinel lymph nodes were detected successfully during operation. There was an average of 2.5 lymph nodes per side per patient. Most of the sentinel lymph nodes were in the level II and level III regions of the ipsilateral side of the neck, and there were bilateral sentinel nodes in patients suffered from superglottic carcinoma. Three patients' sentinel lymph nodes were found to be positive in the frozen inspection, and the routine histopathology confirmed the result. The micrometastasis rate was 10.7% (3/28). There were no metastatic lymph nodes found in patients who were negative for the sentinel lymph nodes during the operative frozen histopathology. The predicted value of the sentinel lymph nodes to the cervical lymph node metastasis was 100 per cent.

CONCLUSION

There is a very important predicted value of sentinel lymph nodes in the cervical metastasis of patients suffered from laryngeal and hypopharyngeal carcinomas. It could reduce the neck dissection in patients with laryngeal and hypopharyngeal carcinomas.

[Factors affecting prognosis of papillary thyroid carcinoma with bilateral cervical lymph node metastases]

One hundred thirty nine cases of papillary thyroid carcinoma with bilateral lymph node metastases were reviewed. They were surgically treated at the Cancer Hospital of Shanghai Medical University in the years from 1956 through 1990. There were 73 men and 66 women with a median age of 35 (range 11-70) years. The median follow-up period was 11 years. Kaplan-Meier survival curves were calculated for the population. The overall survival rate was 94.7% at 5 years, 85.9% at 10 years, and 82.3% at 15 years. In univariate analysis, factors influencing prognosis are age at diagnosis, tumor size, extrathyroidal invasion, residual tumor and thoroughness of excision. When Cox proportional risk model was applied to analyze the survival data, factors of survival significance are the age at diagnosis and thoroughness of excision.