Objective Owing to antibiotic abuse and the subsequent development of antibiotic resistance, bacterial infection has become one of the most persistent unresolved problems. New antibacterial agents, especially those that are environmental-friendly, are urgently needed.Methods Melanin extracted by filtration centrifugation and acid and proteolytic hydrolysis was characterized using UV, FTIR, TEM, and XPS. Photothermal conversion was calculated, and the bacteriostatic effects, in vitro and in vivo, were assessed by plate counting and ratios (%) of wound areas.Results Natural melanin hydrolyzed by trypsin had good photothermal conversion effects, which resulted in superior bacteriostatic activities. The extracted melanin along with laser NIR irradiation at 808 nm promoted the healing of wounds infected by drug-resistant bacteria in vivo and was biocompatible according to toxicity tests in vivo and in vitro.Conclusion The present findings indicated a safe and efficient method of developing natural antibacterial agents.
Objective Long-term seroprotection via the hepatitis A vaccine is essential for the prevention of disease from the hepatitis A virus (HAV). Due to documented difficulties during decade-long follow-ups after receiving vaccines, statistical-modeling approaches have been applied to predict the duration of immune protection.Methods Based on five-year follow-up data from a randomized positive-controlled trial among Chinese children (1–8 years old) following a 0, 6 months vaccination schedule, a power-law model accounting for the kinetics of B-cell turnover, as well as a modified power-law model considering a memory-B-cell subpopulation, were fitted to predict the long-term immune responses induced by HAV vaccination (Healive or Havrix). Anti-HAV levels of each individual and seroconversion rates up to 30 years after vaccination were predicted.Results A total of 375 participants who completed the two-dose vaccination were included in the analysis. Both models predicted that, over a life-long period, participants vaccinated with Healive would have close but slightly higher antibody titers than those of participants vaccinated with Havrix. Additionally, consistent with previous studies, more than 90% of participants were predicted to maintain seroconversion for at least 30 years. Moreover, the modified power-law model predicted that the antibody titers would reach a plateau level after nearly 15 years post-vaccination.Conclusions Based on the results of our modeling, Healive may adequately induce long-term immune responses following a 0, 6 months vaccination schedule in children via induction of memory B cells to provide stable and durable immune protection.
Objective The definite diagnosis of human and animal prion diseases depends on the examination of special pathological changes and/or detection of PrPSc in the brain tissues of suspected cases. Thus, developing methods to obtain PrP antibody with good specificity and sensitivity is fundamental for prion identification.Methods We prepared a PrP-specific polyclonal antibody (pAb P54) in a PRNP-knockout mouse model via immunization with recombinant full-length human PrP protein residues 23–231. Thereafter, we verified that pAb in Western blot, immunohistochemistry (IHC), and immunofluorescent (IFA) assays.Results Western blot illustrated that the newly prepared pAb P54 could react with recombinant PrP protein, normal brain PrPC from healthy rodents and humans, and pathological PrPSc in the brains of experimental rodents infected with scrapie and humans infected with different types of prion diseases. The electrophoretic patterns of brain PrPC and PrPSc observed after their reaction with pAb P54 were nearly identical to those produced by commercial PrP monoclonal antibodies. Three glycosylated PrP molecules in the brain homogenates were clearly demonstrated in the reactions of these molecules with pAb P54. IHC assay revealed apparent PrP deposits in the GdnCl-treated brain slices of 139A-infected mice and 263K-infected hamsters. IFA tests with pAb P54 also showed clear green signals surrounding blue-stained cell nuclei.Conclusion The newly prepared pAb P54 demonstrated reliable specificity and sensitivity and, thus, may have potential applications not only in studies of prion biology but also in the diagnosis of human and experimental rodent prion diseases.
Objective To determine the factors influencing insomnia and construct early insomnia warning tools for rescuers to informbest practices for early screening and intervention.Methods Cluster sampling was used to conduct a cross-sectional survey of 1,133 rescuers from one unit in Beijing, China. Logistic regression modeling and R software were used to analyze insomnia-related factors and construct a PRISM model, respectively.Results The positive rate of insomnia among rescuers was 2.74%. Accounting for participants’ age, education, systolic pressure, smoking, per capita family monthly income, psychological resilience, and cognitive emotion regulation, logistic regression analysis revealed that, compared with families with an average monthly income less than 3,000 yuan, the odds ratio (OR) values and the [95% confidence interval (CI)] for participants of the following categories were as follows: average monthly family income greater than 5,000 yuan: 2.998 (1.307–6.879), smoking: 4.124 (1.954–8.706), and psychological resilience: 0.960 (0.933–0.988). The ROC curve area of the PRISM model (AUC) = 0.7650, specificity = 0.7169, and sensitivity = 0.7419.Conclusion Insomnia was related to the participants’ per capita family monthly income, smoking habits, and psychological resilience on rescue workers. The PRISM model’s good diagnostic value advises its use to screen rescuer early sleep quality. Further, advisable interventions to optimize sleep quality and battle effectiveness include psychological resilience training and smoking cessation.
Objective The objective of this report was to demonstrate the clinical application of free flow-through anterolateral thigh flaps for the treatment of high-tension electrical wrist burns.Methods We collected the data of 8 patients with high-tension electrical wrist burns admitted to Beijing Jishuitan Hospital from January 2014 to December 2018. The clinical and pathological data were extracted from electronic hospital medical records. We obtained follow-up information through clinic visits.Results The injury sites for all 8 patients were the wrists, specifically 5 right and 3 left wrists, all of which were on the flexor side. Five patients had ulnar artery embolism necrosis and patency, with injury to the radial artery. Two patients had ulnar and radial arterial embolization and necrosis. The last patient had ulnar arterial embolization and necrosis with a normal radial artery. After debridement, the wound area ranged from 12 cm × 9 cm to 25 cm × 16 cm. The diagnoses for the eight patients were type II to type III high-tension electrical wrist burns. Free flow-through anterolateral thigh flaps (combined with great saphenous vein transplantation if necessary) were used to repair the wounds. The prognosis for all patients was good after six months to one year of follow-up.Conclusion Treating wrist types II and III high-tension electrical burns is still challenging in clinical practice. The use of free flow-through anterolateral thigh flaps (combined with great saphenous vein transplantation if necessary) to repair the wound and to restore the blood supply for the hand at the same time is a good choice for treating severe wrist electrical burns.