Machine Learning-Guided Prediction of Antigen-Reactive In Silico Clonotypes Based on Changes in Clonal Abundance through Bio-Panning.

c-Met is a promising target in cancer therapy for its intrinsic oncogenic properties. However, there are currently no c-Met-specific inhibitors available in the clinic. Antibodies blocking the interaction with its only known ligand, hepatocyte growth factor, and/or inducing receptor internalization have been clinically tested. To explore other therapeutic antibody mechanisms like Fc-mediated effector function, bispecific T cell engagement, and chimeric antigen T cell receptors, a diverse panel of antibodies is essential. We prepared a chicken immune scFv library, performed four rounds of bio-panning, obtained 641 clones using a high-throughput clonal retrieval system (TrueRepertoireTM, TR), and found 149 antigen-reactive scFv clones. We also prepared phagemid DNA before the start of bio-panning (round 0) and, after each round of bio-panning (round 1-4), performed next-generation sequencing of these five sets of phagemid DNA, and identified 860,207 HCDR3 clonotypes and 443,292 LCDR3 clonotypes along with their clonal abundance data. We then established a TR data set consisting of antigen reactivity for scFv clones found in TR analysis and the clonal abundance of their HCDR3 and LCDR3 clonotypes in five sets of phagemid DNA. Using the TR data set, a random forest machine learning algorithm was trained to predict the binding properties of in silico HCDR3 and LCDR3 clonotypes. Subsequently, we synthesized 40 HCDR3 and 40 LCDR3 clonotypes predicted to be antigen reactive (AR) and constructed a phage-displayed scFv library called the AR library. In parallel, we also prepared an antigen non-reactive (NR) library using 10 HCDR3 and 10 LCDR3 clonotypes predicted to be NR. After a single round of bio-panning, we screened 96 randomly-selected phage clones from the AR library and found out 14 AR scFv clones consisting of 5 HCDR3 and 11 LCDR3 AR clonotypes. We also screened 96 randomly-selected phage clones from the NR library, but did not identify any AR clones. In summary, machine learning algorithms can provide a method for identifying AR antibodies, which allows for the characterization of diverse antibody libraries inaccessible by traditional methods.

The composite anterolateral thigh flap for knee extensor and skin reconstruction.

The simultaneous reconstruction of a skin defect and lost extensor mechanism of the knee joint is difficult. We present a 31-year-old male who lost the patella and had a 9 × 10 cm skin defect after a total patellectomy for an infected open patellar fracture. A composite anterolateral thigh (ALT) flap including vascularized skin and fascia lata (FL) was elevated. The FL was folded and sutured to the remaining patellar tendon. The skin flap covered the skin defect. The wound healed uneventfully. Thirty months later, the active range of motion of the knee joint was 0°-120° and the extension strength of the knee joint was normal. He could stand on his right leg and walk without assistance. The composite ALT flap is a valuable option in knee reconstruction after a total patellectomy.

Mucoepidermoid carcinoma of the lacrimal sac after dacryocystectomy for squamous papilloma.

A mass that recurred after dacryocystectomy for benign squamous papilloma of the lacrimal sac was diagnosed as a high-grade mucoepidermoid carcinoma in a 53-year-old man on histopathology. Local excision to the orbital periosteum was performed and gave a margin free of invasion. Neither local recurrence nor systemic metastasis was found 3 years after local excision. Mucoepidermoid carcinoma of the lacrimal sac is extremely rare and spreads locally in an aggressive manner; a cure typically requires exenteration, radical resection, or adjuvant radiotherapy. In this rare case, despite the high malignancy, the patient underwent successful local excision, achieved an aesthetically satisfying result, and has had a long-term cancer-free period.

Trifurcated radial nerve in the spiral groove of the humerus.

A 62-year-old man presented with a nonunion of the humerus shaft. Using a standard triceps splitting approach, a longitudinal incision along the posterior aspect of the arm was created. Three independent radial nerves coursed posteriorly and inferolaterally around the humerus were identified in spiral groove. Three nerves resembled in the size, color, and course in the operative field. Although the prevalence of the anomaly is probably quite low, the possibility of identification of this anomalous condition of radial nerve should be kept in mind when performing posterior approach on the humerus.

Percutaneous temporal wiring method for minimally invasive plate osteosynthesis of distal femoral fractures.

The surgical reduction of distal femoral fractures with minimally invasive plate osteosynthesis is difficult and the maintenance of the reduction can involve high exposures to radiation. We designed an effective fracture reduction method involving a percutaneous temporal wiring technique for the reduction of distal femoral fractures with oblique or spiral fracture components during surgery with minimally invasive plate osteosynthesis. Our method consistently reduced these fractures satisfactorily. The maintenance of reduction and plate fixation were easy with our method and the radiation exposure during the operation was reduced.