Antibiotic-loaded bone cement fixation technique combined with bilateral pectoralis major muscle flaps tension-free management for sternal infection after midline sternotomy.

INTRODUCTION: Deep sternal wound infection (DSWI) after midline sternotomy of cardiac surgery is a challenging complication that affects the outcome of surgery. This study aims to assess the clinical effectiveness of the antibiotic-loaded bone cement fixation technique combined with bilateral pectoralis major muscle flaps tension-free management in the treatment of DSWI. METHODS: We retrospectively analyzed 5 patients with DSWI who underwent antibiotic-loaded bone cement combined with bilateral pectoralis major muscle flaps for chest wall reconstruction after sternotomy for cardiac surgery in a tertiary hospital in China from January 2020 to December 2021. The clinical and follow-up data were retrospectively analyzed. RESULTS: All patients had no perioperative mortalities, no postoperative complications, 100% wound healing, and an average hospital stay length of 24 days. The follow-up periods were from 6 to 35 months (mean 19.6 months). None of the cases showed wound problems after initial reconstruction using antibiotic-loaded bone cement combined with bilateral pectoralis major muscle flaps. CONCLUSIONS: We report our successful treatment of DSWI, using antibiotic-loaded bone cement fixation technique combined with bilateral pectoralis major muscle flaps tension-free management. The clinical and follow-up results are favorable.

High-Throughput Screening of Functional Neo-Antigens and Their Specific T-Cell Receptors via the Jurkat Reporter System Combined with Droplet Microfluidics.

T-cell receptor (TCR)-engineered T cells can precisely recognize a broad repertoire of targets derived from both intracellular and surface proteins of tumor cells. TCR-T adoptive cell therapy has shown safety and promising efficacy in solid tumor immunotherapy. However, antigen-specific functional TCR screening is time-consuming and expensive, which limits its application clinically. Here, we developed a novel integrated antigen-TCR screening platform based on droplet microfluidic technology, enabling high-throughput peptide-major histocompatibility complex (pMHC)-to-TCR paired screening with a high sensitivity and low background signal. We introduced DNA barcoding technology to label peptide antigen candidate-loaded antigen-presenting cells and Jurkat reporter cells to check the specificity of pMHC-TCR candidates. Coupled with the next-generation sequencing pipeline, interpretation of the DNA barcodes and the gene expression level of the Jurkat T-cell activation pathway provided a clear peptide-MHC-TCR recognition relationship. Our proof-of-principle study demonstrates that the platform could achieve pMHC-TCR paired high-throughput screening, which is expected to be used in the cross-reactivity and off-target high-throughput paired testing of candidate pMHC-TCRs in clinical applications.

[Application of homemade antibiotic bone cement rod in tibial screw canal osteomyelitis].

Objective: To investigate the effectiveness of homemade antibiotic bone cement rod in the treatment of tibial screw canal osteomyelitis by Masquelet technique. Methods: A clinical data of 52 patients with tibial screw canal osteomyelitis met the criteria between October 2019 and September 2020 was retrospectively analyzed. There were 28 males and 24 females, with an average age of 38.6 years (mean, 23-62 years). The tibial fractures were treated with internal fixation in 38 cases and external fixation in 14 cases. The duration of osteomyelitis was 6 months to 20 years with a median of 2.3 years. The bacterial culture of wound secretions showed 47 positive cases, of which 36 cases were infected with single bacteria and 11 cases were infected with mixed bacteria. After thorough debridement and removal of internal and external fixation devices, the locking plate was used to fixed the bone defect. The tibial screw canal was filled with the antibiotic bone cement rod. The sensitive antibiotics were given after operation and the 2nd stage treatment was performed after infection control. The antibiotic cement rod was removed and the bone grafting in the induced membrane was performed. After operation, the clinical manifestations, wound, inflammatory indexes, and X-ray films were monitored dynamically, and the postoperative bone infection control and bone graft healing were evaluated. Results: Both patients successfully completed the two stages of treatments. All patients were followed up after the 2nd stage treatment. The follow-up time was 11 to 25 months (mean, 18.3 months). One patient had poor wound healing and the wound healed after enhanced dressing change. X-ray film showed that the bone grafting in the bone defect healed and the healing time was 3-6 months, with an average of 4.5 months. The patient had no recurrence of infection during the follow-up period. Conclusion: For the tibial screw canal osteomyelitis, the homemade antibiotic bone cement rod can reduce the recurrence rate of infection and obtain a good effectiveness, and has the advantages of simple operation and less postoperative complications.

The combined application of antibiotic-loaded bone cement and vacuum sealing drainage for sternal reconstruction in the treatment of deep sternal wound infection.

BACKGROUND: Deep sternal wound infection (DSWI) is a rare but serious complication after median sternotomy, and treatment success depends mainly on surgical experience. Traditional treatment methods for DSWI include complete debridement, vacuum sealing drainage wound therapy and sometimes transposition of muscle flap. This study aimed to evaluate the utility of antibiotic-loaded bone cement combined with vacuum sealing drainage on DSWI and explore the effect of this treatment on lung function. METHODS: Between January 2018 and December 2019, we treated 12 patients suffering a mediastinitis and open thorax using antibiotic-loaded bone cement combined with vacuum sealing drainage. Subsequently, the blood and local concentration of antibiotic were measured. The patient characteristics, pulmonary function, were retrospectively analyzed. Subjects were followed up for 12 months. RESULTS: There were no intraoperative deaths. All patients' healing wounds were first-stage healing without complications and reoperation, the mean hospital stay was 20.2 ± 3.5 days. Local vancomycin concentrations largely exceeded the ones needed for their efficacy while little antibiotic was found in the blood. Pulmonary function testing was improved 2 weeks after the operation. No infection reoccurred in12-month follow-up. CONCLUSIONS: The antibiotic-loaded bone cement combined with vacuum sealing drainage might be an effective method for the sternal reconstruction of deep sternal wound infection and it can improve the patient's lung function in a short time.

PTPRO knockdown protects against inflammation in hemorrhage shock-induced lung injury involving the NF-κB signaling pathway.

BACKGROUND: Hemorrhage shock (HS) is characterized by decreased tissue oxygenation and organ damage due to severe blood loss. Protein tyrosine phosphatase receptor type O (PTPRO) is abnormally up-regulated in the rat lungs after trauma/HS. METHODS: To elucidate the regulatory mechanism of PTPRO in lung inflammation following HS, we established a rat model of HS via withdrawing blood by a catheter inserted into the femoral artery followed by resuscitation. The rats were infected with lentivirus harboring short hairpin RNA (shRNA) targeting PTPRO by intratracheal instillation. RESULTS: PTPRO was significantly up-regulated in rat lungs after HS. PTPRO knockdown enhanced epithelial integrity and reduced capillary leakage by up-regulating tight junction proteins zonula occludens-1 (ZO-1) and occludin (OCC) in the lungs. Besides, HS-induced myeloperoxidase activity and inflammatory cell infiltration was mitigated by PTPRO knockdown. The expression of inflammatory cytokines/chemokines (TNF-α, IL-6, MIP-2, MCP-1, and KC) in the lungs and bronchoalveolar lavage fluid was regressed after PTPRO knockdown. The nuclear factor kappa B (NF-κB) pathway was involved in HS-induced lung inflammation. PTPRO down-regulation inhibited the NF-κB pathway activation by suppressing the phosphorylation of NF-κB and its translocation from the cytoplasm into the nucleus in HS. CONCLUSION: Taken together, we demonstrated that PTPRO knockdown may contribute to attenuating inflammation in HS-induced lung injury via inhibiting NF-κB pathway activation.

A Novel Proteogenomic Integration Strategy Expands the Breadth of Neo-Epitope Sources.

Tumor-specific antigens can activate T cell-based antitumor immune responses and are ideal targets for cancer immunotherapy. However, their identification is still challenging. Although mass spectrometry can directly identify human leukocyte antigen (HLA) binding peptides in tumor cells, it focuses on tumor-specific antigens derived from annotated protein-coding regions constituting only 1.5% of the genome. We developed a novel proteogenomic integration strategy to expand the breadth of tumor-specific epitopes derived from all genomic regions. Using the colorectal cancer cell line HCT116 as a model, we accurately identified 10,737 HLA-presented peptides, 1293 of which were non-canonical peptides that traditional database searches could not identify. Moreover, we found eight tumor neo-epitopes derived from somatic mutations, four of which were not previously reported. Our findings suggest that this new proteogenomic approach holds great promise for increasing the number of tumor-specific antigen candidates, potentially enlarging the tumor target pool and improving cancer immunotherapy.

Discovery of Missing Proteins from an Aneuploidy Cell Line Using a Proteogenomic Approach.

With the steadfast development of proteomic technology, the number of missing proteins (MPs) has been continuously shrinking, with approximately 1470 MPs that have not been explored yet. Due to this phenomenon, the discovery of MPs has been increasingly more difficult and elusive. In order to face this challenge, we have hypothesized that a stable aneuploid cell line with increased chromosomes serves as a useful material for assisting MP exploration. Ker-CT cell line with trisomy at chromosome 5 and 20 was selected for this purpose. With a combination strategy of RNA-Seq and LC-MS/MS, a total of 22 178 transcripts and 8846 proteins were identified in Ker-CT. Although the transcripts corresponding to 15 and 15 MP genes located at chromosome 5 and 20 were detected, none of the MPs were found in Ker-CT. Surprisingly, 3 MPs containing at least two unique non-nest peptides of length ≥9 amino acids were identified in Ker-CT, whose genes are located on chromosome 3 and 10, respectively. Furthermore, the 3 MPs were verified using the method of parallel reaction monitoring (PRM). These results suggest that the abnormal status of chromosomes may not only impact the expression of the corresponding genes in trisomy chromosomes, but also influence that of other chromosomes, which benefits MP discovery. The data obtained in this study are available via ProteomeXchange (PXD028647) and PeptideAtlas (PASS01700), respectively.

Antibiotic-loaded bone cement combined with vacuum sealing drainage to treat deep sternal wound infection following cardiac surgery: the first case report.

BACKGROUND: Deep sternal wound infection (DSWI) is a rare but serious complication after median sternotomy, and treatment success depends mainly on surgical experience. Here we first present a case of a patient successfully treated for antibiotic-loaded bone cement (ALBC) combined with vacuum sealing drainage (VSD) of DSWI. CASE PRESENTATION: This case report presented a patient who underwent open heart surgery, and suffered postoperatively from a DSWI associated with enterococcus cloacae. Focus debridement combined with ALBC filling and VSD was conducted in stage I. Appropriate antibiotics were started according to sensitivity to be continued for 2 weeks until the inflammatory markers decreased to normal. One month after the surgery, patient's wound was almost healed and was discharged from hospital with a drainage tube. Two months after the stage I surgery procedure, the major step was removing the previous ALBC, and extensive debridement in stage II. The patient fully recovered without further surgical treatment. CONCLUSIONS: The results of this case suggest that ALBC combined with VSD may be a viable and safe option for deep sternal wound reconstruction.

[Modified induced membrane technique and pedicled skin (myocutaneous) flap for chronic tibial osteomyelitis in patients with diabetes].

OBJECTIVE: To investigate the effectiveness of modified induced membrane technique and pedicled skin (myocutaneous) flap for chronic tibial osteomyelitis in patients with diabetes. METHODS: A clinical data of 22 diabetic patients with chronic tibial osteomyelitis between January 2017 and March 2019 was retrospectively analyzed. There were 15 males and 7 females with an average age of 52 years (range, 44-65 years). The course of diabetes was 3-12 years (mean, 6.1 years). The course of chronic osteomyelitis was 4 months to 7 years (mean, 3.3 years). The chronic osteomyelitis was rated as type Ⅲ in 9 cases and as type Ⅳ in 13 cases according to the Cierny-Mader classification criteria. Bacterial culture showed 21 cases of single bacterial infection and 1 case of mixed bacterial infection. Preoperative color Doppler ultrasound and CT angiography confirmed that the anterior and posterior tibial arteries were unobstructed. In the first stage of treatment, the bone and soft tissue defects were filled with antibiotic bone cement after the lesion was thoroughly debrided; the length of bone defect was 4-9 cm (mean, 5.6 cm), and the size of soft tissue defect was 5 cm×2 cm to 10 cm×7 cm. After 7-10 days, the bone cement was removed and a new antibiotic bone cement was filled into the bone defect. Meanwhile, the pedicled skin (myocutaneous) flap was performed to repair the wound. After 7-12 weeks, the inflammatory indexes returned to normal, autogenous iliac bone or combined with artificial bone was used to repair the bone defect in the second stage of treatment. The wound healing, bone defect healing, complications, and the number of successful treatments were recorded. The satisfaction of the skin flap efficacy and the function of the affected limb were evaluated. RESULTS: Local necrosis of the skin flap occurred in 3 cases after operation, leading to delayed healing of the wound; the other 19 flaps survived successfully, leading to primary healing of the wound. The skin grafts survived completely and the incisions healed by first intention. All cases were followed up 13-28 months with an average of 20 months. The infection recurred in 2 cases within 12 months after operation, and the bone defects healed after treated by modified induced membrane technique. The bone defect healing rate was 100%; the bone healing time was 6-10 months, with an average of 8.9 months; the infection control rate and successful treatment rate were 90.9% (20/22) and 90.9% (20/22), respectively. At 12 months after operation, according to the satisfaction evaluation standard of skin flap efficacy formulated by ZHANG Hao et al., all were satisfied. According to Johner-Wruhs adjacent joint function method, the limb function recovery was excellent in 13 cases, good in 7 cases, and fair in 2 cases, with an excellent and good rate of 90.9%. CONCLUSION: For the treatment of chronic tibial osteomyelitis in patients with diabetes without vascular occlusion, the modified induced membrane technique and pedicled skin (myocutaneous) flap can repair bone and soft tissue defects, and control the infection at the same time, the short- and medium-term effectiveness are good.

D283 Med, a Cell Line Derived from Peritoneal Metastatic Medulloblastoma: A Good Choice for Missing Protein Discovery.

Since the Chromosome-Centric Human Proteome Project (C-HPP) was launched in 2010, many techniques have been adopted for the discovery of missing proteins (MPs). Because of these efforts, only 1481 MPs remained as of July 2020; however, by relying only on technique optimization, researchers have reached a bottleneck in MP discovery. Protein expression is tissue- or cell-type-dependent. The tissues of the human testis and brain have been reported to harbor a large number of tissue-specific genes and proteins; however, few studies have been performed on human brain tissue or cells to identify MPs. Herein a metastatic cell line derived from brain cancer, D283 Med, was used to search for MPs. With a traditional and simple shotgun workflow to separate the peptides into 20 fractions, 12 MPs containing at least two unique non-nested peptides (amino acid length ≥9) were identified in this cell line with a protein false discovery rate of <1%. Following the same experimental protocol, only one MP was found in a nonmetastatic brain cancer cell line, U-118 MG. Furthermore, 12 MPs were verified as having two non-nested unique peptides by matching them with corresponding chemically synthesized peptides through parallel reaction monitoring. These results clearly demonstrate that the appropriate selection of experimental materials, either tissues or cell lines, is imperative for MP discovery. The data obtained in this study are available via ProteomeXchange (PXD021482) and PeptideAtlas (PASS01627).

Exploration of Missing Proteins by a Combination Approach to Enrich the Low-Abundance Hydrophobic Proteins from Four Cancer Cell Lines.

The mission of the Chromosome-Centric Human Proteome Project (C-HPP) to discover missing proteins (MPs) has become increasingly difficult due to the remaining low-abundance, high-hydrophobicity, or low-molecular-weight MPs. We have reported two approaches to resolve these identification problems for the low-abundance and high-hydrophobicity MPs, respectively. In this study, to improve the identification of low-abundance MPs with high hydrophobicity, we combined two approaches and obtained MPs from several different cancer cell lines. Their membrane fractions were isolated by ultracentrifugation, and the low-abundance proteins were enriched at the protein level with the ProteoMiner kit. After that, the peptides from the enriched proteins were separated by high concentrations of organic solvents according to their hydrophobicity as the first dimension of separation at the peptide level, and the second and third dimensions of separation involved a high pH reversed-phase and an acid reversed-phase column, respectively. In total, 16 MPs (at least two non-nested unique peptides with ≥9 amino acids) with 61 unique peptides were identified from four human cancer cell lines, including 2, 8, 2, and 7 MPs from HeLa, HCT116, SNU-1, and HepG2 cells, respectively. Furthermore, all MPs were verified with two non-nested unique peptides through parallel reaction monitoring (PRM) by matching the peptides with their chemically synthesized peptides. Interestingly, two additional MPs were verified from the same cell line by PRM assay, although the two non-nested unique peptides with ≥9 amino acids for each MP were identified from different MS injections or cell lines by data-dependent acquisition (DDA). Thus, a total of 18 MPs were dug out in this study. The data are available via ProteomeXchange (PXD014058) and PeptideAtlas (PASS01388).

[Effectiveness of improved interosseous dorsal artery reversed island flap for dorsal skin and soft tissue defect of hand].

OBJECTIVE: To discuss the effectiveness of improved interosseous dorsal artery reversed island flap to repair dorsal skin and soft tissue defect of the hand. METHODS: Between March 2009 and September 2012, 29 cases of dorsal skin and soft tissue defects were treated with improved interosseous dorsal artery reversed island flap. Of 29 cases, there were 17 males and 12 females, aged 23-71 years (mean, 47 years); and the left hand was involved in 12 cases and the right hand in 17 cases. There were 11 cases of avulsion injury, 9 cases of crushing injury, 5 cases of strangulation injury, and 2 cases of traffic accident injury; the interval of injury and admission was 1-7 hours (mean, 4 hours). Two patients had scar contracture. The locations of soft tissue defects were dorsal hands in 21 cases, first webs in 5 cases, and dorsal thumb in 3 cases. The size of soft tissue defects ranged from 4 cm x 3 cm to 10 cm x 8 cm. One-stage repair was performed in 11 cases, and two-stage repair in 18 cases. The size of flaps ranged from 5.5 cm x 4.5 cm to 12.0 cm x 10.0 cm. The donor sites were sutured directly or repaired by skin grafting. RESULTS: All flaps survived, and wounds healed in first stage. And the grafted skins at donor sites all survived, and incisions all healed in first stage. Twenty-six patients were followed up 3 months-3 years (mean, 19.5 months). Bulky flap was observed in 3 cases, and defatted operation was performed after 6 months; the other flaps had good appearance and texture, and wrist function was normal. According to total angle of motion (TAM) systematic evaluation, the results were excellent in 17 cases, good in 6 cases, and fair in 3 cases at 3 months after operation. CONCLUSION: Improved interosseous dorsal artery reversed island flap has the advantages of easy-to-obtain, simple operation, and high survival rate of flaps, so it is an effective method to repair dorsal skin and soft tissue defect of the hand.

[Reconstruction of donor site defect after harvesting anterolateral thigh flap by V-Y flap pedicled with the lateral superior genicular perforator].

OBJECTIVE: To investigate the clinical application of V-Y flap pedicled with the lateral superior genicular perforator for donor site defect after harvesting anterolateral thigh flap. METHODS: From June 2011 to June 2012, 9 cases with defects at hands and feet were treated with anterolateral thigh flaps. The defects left at the donor sites were consequently reconstructed with V-Y flap pedicled with the lateral superior genicular perforator. The defects left by V-Y flap were closed directly. RESULTS: All the 9 anterolateral thigh flap survived completely. 5 flaps underwent thinning surgery 6-8 months after operation. The flaps had a good appearance, texture, color and elasticity. The 8 perforator flaps survived completely with partial necrosis in 1 flap at the proximal end. The average healing time was 17 days. There was no obvious depression at donor sites with normal function. CONCLUSIONS: The method is easily performed with optional therapeutic effect. It is a modified improvement for the anterolateral thigh flap.