The development of polydopamine (PDA) coatings with a nanometer-scale thickness on surfaces is highly desirable for exploiting the novel features arising from the specific structure on the molecular level. Exploring the mechanisms of thin-film growth is helpful for attaining desirable control over the useful properties of materials. We present a systematic study demonstrating the growth of a PDA thin film on the surface of mica in consecutive short deposition time intervals. Film growth at each deposition time was monitored through instrumental techniques such as atomic force microscopy (AFM), water contact angle (WCA) analysis, and X-ray photoelectron spectroscopy (XPS). Film growth was initiated by adsorption of the PDA molecules on mica, with subsequent island-like aggregation, and finally, a complete molecular level PDA film was formed on the surface due to further molecular adsorption. A duration of 60−300 s was sufficient for complete formation of the PDA layer within the thickness range of 0.5−1.1 nm. An outstanding feature of PDA ultrathin films is their ability to act as a molecular adhesive, providing a foundation for constructing functional surfaces. We also explored antimicrobial applications by incorporating Ag nanoparticles into a PDA film. The Ag NPs/PDA film was formed on a surgical blade and then characterized and confirmed by SEM-EDS and XPS. The modified film inhibited bacterial growth by up to 42% on the blade after cutting through a pork meat sample.

Rationale:Adult-onset Still disease (AOSD) is a rare systemic inflammatory disease of unknown etiology characterized by evanescent salmon-pink rash, spiking fever, arthralgia/ arthritis, and lymphadenopathy. AOSD sometimes was fatal when it is complicated by macrophage activation syndrome (MAS) or hemophagocytic lymphohistiocytosis (HLH). Nonetheless, the literature provides no recommendations for treatment of AOSD patients with severe sepsis.Patient concerns:A previously healthy 65-year-old man with history of AOSD was referred to our hospital for persistent right lower quadrant abdominal pain for 2 days. One week later, an abdominal wall abscess and hematoma developed by extravasation from the inferior epigastric vessels, complicated by necrotizing fasciitis of the right thigh and groin region. To our best knowledge, this case was the first reported case of a perforated appendix complicated with necrotizing fasciitis in a patient with AOSD.Diagnoses:The patient was diagnosed as acute appendicitis complicated with necrotizing fasciitis and abdominal wall abscess.Interventions:This case received intravenous tigecycline injection and daily 10 mg prednisolone initially, and shifted to daily intravenous hydrocortisone 200 mg for suspected MAS or HLH. This patient underwent surgical intervention and debridement for necrotizing fasciitis.Outcomes:The patient's symptoms progressed worse rapidly. He died from cytomegalovirus viremia and bacterial necrotizing fasciitis complicated by septic shock.Lessons:(1) The steroid dose was difficult to titrate when AOSD complicated by sepsis. The differential diagnosis from MAS/HLH with bacterial/viral infection related severe sepsis was difficult but critical for decision making from clinicians and rheumatologists. (2) The conservative treatment with antibiotics for perforated appendix is safe but has a higher failure rate in immunocomprised patients such as systemic lupus erythematosus and AOSD. Early surgical intervention might contribute to better outcome. (3) The abdominal wall abscess can be spread from intra-abdominal lesion through the inferior epigastric vessels which were as weak points of abdominal wall. Imaging examinations contribute to acute diagnosis and help surgeons perform surgical interventions to prevent morbidity and mortality.

Rationale:Thromboangiitis obliterans (TAOs, or Buerger's disease) present as a non-atherosclerotic segmental occlusive vasculitis within medium- and small-sized blood vessels. TAO frequently occurs in young adults and is associated with cigarette smoking. At present, there are no accurately defined treatments for TAO.Patient concerns:A 34-year-old Asian woman with a 20-year history of heavy cigarette smoking and recurrent, small, and self-limited lower limb ulcerations since adolescence, presented with persisting unhealed ulcerations on both ankles for 6 months. Her wound healing response was poor following the 2-month administration of colchicine, prednisolone, hydroxychloroquine, and mycophenolic acid.Diagnosis:The patient was diagnosed with TAO with hyperimmunoglobulin E and refractory ulcerations on her ankles.Interventions:The patient received monthly omalizumab (300 mg) and previous medications for 2 months and shifted to omalizumab and colchicine without mycophenolic acid and hydroxychloroquine because of onychomadesis, which was considered to be a possible adverse drug reaction.Outcomes:The wounds healed almost completely. The administration of omalizumab and colchicine will be continued until they the wounds are fully healed.Lessons:Mycophenolic acid has a limited function in TAO treatment, especially in cases of refractory skin ulcerations. Omalizumab can be a valuable treatment option for patients with TAO and hyperimmunoglobulin E.

Introduction:Multidrug-resistant Acinetobacter baumannii (MDRAB) pneumonia with severe sepsis in a patient with rheumatoid arthritis (RA), who is predisposed after treatment with tumor necrosis factor inhibitor (TNFI), is a rare severe infection and can be successfully treated with prompt antibiotics.Case presentation:A 75-year-old woman was diagnosed with RA >30 years previously. After inadequate treatment responses to conventional disease-modifying antirheumatic drugs (DMARDs), she developed progressive RA, including swollen joints in both hands, and had a high disease activity score of 4.96 when presenting at our rheumatology clinic. She had started taking the TNFI, golimumab (50 mg/month), 3 years before and developed a productive cough 4 weeks before this admission. One week after admission, she developed fever, dyspnea, hypoxemia, tachycardia, and increased serum C-reactive protein level.Diagnosis:Chest plain film (CxR) and computed tomography of the chest showed hospital-acquired pneumonia; microbial examination of the sputum showed the presence of MDRAB.Therapeutics:She was prescribed a full course of antibiotics with cefoperazone sulbactam.Outcomes:CxR showed complete remission of pneumonia.Conclusion:Biological DMARDs, such as TNFI, act as a double-edged sword: these drugs are used to treat autoimmune diseases, but they increase the risk of infection. The trend toward antibiotic resistance and persistent environmental survival of MDRAB is an emerging problem in countries with high rates of antibiotic abuse. TNFI may affect intestinal immunity by inducing dysbiosis, which affects T helper 17–mediated mucosal immunity and can contribute to A baumannii colonization and the development of MDRAB in frequently hospitalized patients.