A dynamic kinetic model is presented for the UVC/H2O2-driven process. The model comprises 103 reactions, including background species, such as HCO3-/CO32-, NO2-, NO3-, SO42-, Cl-, and H2PO4-/HPO42/PO43- anions, and effluent organic matter (EfOM) was validated based on experimental data obtained for the photooxidation of the nonribosomal peptide antibiotic zinc bacitracin (Zn-Bc, 34 μmol L-1). The set of ordinary differential equations for 38 species was combined with the molar balances describing the recirculating tubular photoreactor used. Predictions for the photolytic and UVC/H2O2 processes confirmed the good agreement with experimental data, enabling the estimation of fundamental kinetic parameters, such as the direct photolysis quantum yield (Ф254 nm, Zn-Bc = 0.0143 mol Einstein-1) and the second-order rate constants for the reactions of Zn-Bc with HO•, HO2•, and O2•- radicals (2.64 × 109, 1.63 × 103, and 1.49 × 104 L mol-1 s-1, respectively). The predicted optimum process conditions correspond to [H2O2]0 = 6.8 mmol L-1 and a specific photon emission rate of 11.1 × 10-6 Einstein L-1 s-1. Zn-Bc photooxidation was significantly impacted by wastewater constituents, particularly EfOM and HCO3-/CO32- (i.e., alkalinity), resulting in a degradation rate about 32% lower compared to that obtained in deionized water. In particular, EfOM acts as a strong radical scavenger and inner filter. In addition, simulations pointed out the continuous tubular photochemical reactor as the best configuration for treating Zn-Bc-containing wastewater. This study hence provides a comprehensive modeling approach, especially useful for predicting the effect of complex water matrices on the performance of the UVC/H2O2 treatment process.

The contamination with antibiotic resistance genes (ARGs) in raw drinking water source may pose a direct threat to human health. In this study, metagenomics sequencing and analysis were applied to investigate the ARG pattern in 12 drinking water sources in upper and middle reach of Huaihe River Basin, China. Based on the redundant analysis and multi-linear regression model, location, specific microbial taxa, number of livestock and health facilities significantly influenced the ARG profile in drinking water sources. Besides the cluster effect of ARG in samples from plain and bedrock mountain areas, the samples from fracture aquifer areas also showed a distinctive biogeographic pattern with that from porous aquifer areas. Putative ARGs host Opitutus and Flavobacterium were the enriched biomarkers in plain and fracture aquifer area respectively, which mainly carried bacitracin, multidrug, beta-lactam and tetracycline ARGs. This result illuminated that both natural background and anthropogenic activities in the watershed influenced the ARG profile in natural freshwater system significantly. The low MGEs abundance and absence of pathogen revealed a low ARG dissemination risk in sampled drinking water sources, while Polynucleobacter was an abundant ARGs host and was significantly related to the ARG profile, which indicated that specific bacteria was responsible for ARGs propagation and accumulation in surface freshwater system. Further researches are needed to assess human exposure to raw drinking water source and the potential risk, as well as the species interaction in microbial community and its impact on ARG propagation under oligotrophic condition.

The aim of the study was to conduct a retrospective chart review of patients who underwent betadine/bacitracin continuous irrigation (BBCI) for vascular graft infections (VGIs) to review its use as a treatment option. A retrospective chart review from 2013 to 2017 was conducted of patients with VGIs that were treated with BBCI postremoval of the infected graft. The BBCI is a continuous infusion of 0.25% betadine in normal saline at 0.3 mL/kg/h for 48 hours then followed by bacitracin infusion with a concentration of 50,000 units bacitracin/per liter normal saline at 0.3 mL/kg/h for 72 hours. Descriptive statistics were used to describe the sample. The nine adult patients who received postoperative BBCI had an age range of 30-81 years, with average age of 58.8 years. Five of the subjects were females with four males. A total of nine patients with groin infections were identified, with two aortobifemoral bypasses, two axillofemoral bypasses, three femoral-femoral bypasses, one femoral artery pseudoaneurysm repair with Dacron patch, and one common femoral endarterectomy with Dacron patch. VGIs were identified from 10 days up to 72 months from the original vascular procedure. Six patients had negative wound cultures, while two had wound cultures positive for methicillin-resistant Staphylococcus aureus and one patient had positive culture for Escherichia coli. The length of time of BBCI ranged from 48 to 84 hours with average of 57.6 hours (standard deviation [SD] = 12.7 hours). The length of time of the bacitracin irrigation ranged from 30 to 72 hours with average of 48.4 hours (SD = 14.9 hours). All patients healed their groin wounds except for an 81-year-old patient with aortobifemoral bypass graft who developed ischemic bowel and expired. Patients received at least 6 weeks of intravenous antibiotics followed by oral antibiotic suppression therapy for life. VGIs are a devastating complication associated with a high morbidity. BBCI provides an option for antiseptic irrigation of the vascular graft site postgraft removal to promote wound closure.

Injury to the penis resulting from zipper entrapment is a painful condition that presents a unique anesthetic challenge to the emergency physician and may even require procedural sedation for removal. In this case report, we describe successful removal of zipper entrapment from the penis of a 34-year-old patient after the application of an ultrasound-guided dorsal penile nerve block. We discuss the anatomy, sonographic features, and steps required for the nerve block procedure. © 2017 Wiley Periodicals, Inc. J Clin Ultrasound 45:589-591, 2017.

The Accelerated Stability Assessment Program (ASAP) was applied for the first time to a peptide, the antibiotic active pharmaceutical ingredient bacitracin. Bacitracin and its complex with zinc were exposed to temperature and relative humidity conditions from 50 to 80°C and from 0 to 63% for up to 21 days. High-performance liquid chromatography was used to analyze the stressed samples for both degradant formation and loss of the active (bacitracin A) and two inactive isoforms, with identities confirmed by mass spectrometry. These data were then analyzed using a humidity-corrected Arrhenius equation and isoconversion approach to create a shelf-life predicting model for typical storage conditions. Model fitting was found to be good with low residuals in both temperature and relative humidity axes for all parameters examined. The generated model\'s predictions for both the native and zinc complex of bacitracin for both formation of the major degradation product (F) and loss of the active isoform (A) were consistent with longer-term measured values at 30°C/53%RH and 40°C/75%RH, validating this approach for accelerating the determination of long-term stability of a peptide.

BACKGROUND: Little is known about the epidemiology of allergic contact dermatitis (ACD) in US children. More widespread diagnostic confirmation through epicutaneous patch testing is needed.
OBJECTIVE: The aim was to quantify patch test results from providers evaluating US children.
METHODS: The study is a retrospective analysis of deidentified patch test results of children aged 18 years or younger, entered by participating providers in the Pediatric Contact Dermatitis Registry, during the first year of data collection (2015-2016).
RESULTS: One thousand one hundred forty-two cases from 34 US states, entered by 84 providers, were analyzed. Sixty-five percent of cases had one or more positive patch test (PPT), with 48% of cases having 1 or more relevant positive patch test (RPPT). The most common PPT allergens were nickel (22%), fragrance mix I (11%), cobalt (9.1%), balsam of Peru (8.4%), neomycin (7.2%), propylene glycol (6.8%), cocamidopropyl betaine (6.4%), bacitracin (6.2%), formaldehyde (5.7%), and gold (5.7%).
CONCLUSIONS: This US database provides multidisciplinary information on pediatric ACD, rates of PPT, and relevant RPPT reactions, validating the high rates of pediatric ACD previously reported in the literature. The registry database is the largest comprehensive collection of US-only pediatric patch test cases on which future research can be built. Continued collaboration between patients, health care providers, manufacturers, and policy makers is needed to decrease the most common allergens in pediatric consumer products.

Chagas disease is a vector-borne and potentially fatal parasitic disease that is transmitted by the triatomine bug, a nocturnal feeding, flying arthropod, often referred to by its colloquial name, the \"kissing bug.\" Vector-borne transmission is considered the most important means of spreading Chagas disease in endemic and nonendemic areas. Corrugated cardboard boxes may accelerate the spread of these insect vectors to nonendemic areas through their ability to harbor and transport small terrestrial arthropods such as silverfish, termites, and cockroaches. We report the case of a patient living in northern California who presented to a community clinic 6 weeks after being bitten by a positively identified triatomine bug. A local pest control company identified a total of eight adult Triatoma protracta, nine nymphs, and two eggs; all within the patient\'s bedding. No bugs were found outside of the patient\'s bedroom. The Centers for Disease Control and Prevention confirmed one adult female was positive for Trypanosoma cruzi via polymerase chain reaction. The patient\'s bedroom doubled as an office and regularly received and stored corrugated cardboard shipping boxes. Corrugated cardboard boxes have been used to trap and study the triatomine bug. This is the first documented case that provides circumstantial evidence that corrugated cardboard boxes may be an inadvertent and unrecognized factor in the spread of Chagas disease.

OBJECTIVE: The risk of infection can be reduced in hemodialysis (HD) patients with central venous catheters (CVCs) by using prophylactic intranasal mupirocin or polysporin at the exit site. However, there are concerns about the potential emergence of resistant microorganisms. The purpose of our study was to determine if the use of polysporin double in the treatment of exit site infections was associated with the emergence of yeast positive exit site cultures.
METHODS: In this case control study, we evaluated the risk of developing yeast positive exit site cultures after introducing a polysporin medical directive for the treatment of presumed exit site infections in our HD units. All HD patients using a CVC for blood access at the Ottawa Hospital were eligible for study. Demographic variables, use of polysporin, antibiotics and immunosuppressive medications were compared between those patients with yeast positive exit site cultures and controls.
RESULTS: There was no differences in age, gender or diabetic status between the cases and controls. However, the use of polysporin, antibiotics and immunocompromised status were associated with an increased risk of yeast positive exit site cultures. The relative importance of each of these factors could not be determined using this study design and requires future prospective study.
CONCLUSIONS: The emergence of yeast positive exit site cultures after the introduction of a new medical directive at a tertiary care hospital highlights the difference between medications used for prophylaxis and those used for treatment of CVC infections in high risk dialysis patients.

Burns are a rare but potentially serious complication of povidone-iodine use. This rare adverse drug reaction developed in a 38-year-old woman who underwent laparoscopic right ovarian cystectomy and endometrial ablation as a day procedure involving application of the topical antiseptic 10% povidone-iodine solution. Two days later, the patient was admitted to the hospital with burning, pain, itching, marked redness, and blistering extending from her midback to buttocks. A stain on her back also was evident. Partial-thickness chemical burn was diagnosed. Review of the literature yielded 13 other cases of povidone-iodine-induced burn. This underrecognized adverse effect of povidone-iodine application typically occurs when the povidone-iodine has not been allowed to dry or has been trapped under the body of a patient in a pooled dependent position. The burn is usually seen immediately after the procedure or on the next day, and typically heals with minimum scarring within 3-4 weeks with conservative treatment. The commonly postulated mechanism is a chemical burn due to irritation coupled with maceration, friction, and pressure. Given the widespread use of povidone-iodine and the potential for development of infection after a burn, clinicians need to be aware of this possible povidone-iodine-associated adverse drug reaction, and of preventive measures.

暂无摘要。