Full-Spectrum Utilization of ZIF-67/Ag NPs/NaYF4:Yb,Er Photocatalysts for Efficient Degradation of Sulfadiazine: Upconversion Mechanism and DFT Calculation.

In this work, novel ternary composite ZIF-67/Ag NPs/NaYF4:Yb,Er is synthesized by solvothermal method. The photocatalytic activity of the composite is evaluated by sulfadiazine (SDZ) degradation under simulated sunlight. High elimination efficiency of the composite is 95.4% in 180 min with good reusability and stability. The active species (h+, ·O2 - and ·OH) are identified. The attack sites and degradation process of SDZ are deeply investigated based on theoretical calculation and liquid chromatography-mass spectrometry analysis. The upconversion mechanism study shows that favorable photocatalytic effectiveness is attributed to the full utilization of sunlight through the energy transfer upconversion process and fluorescence resonance energy transfer. Additionally, the composite is endowed with outstanding light-absorbing qualities and effective photogenerated electron-hole pair separation thanks to the localized surface plasmon resonance effect of Ag nanoparticles. This work can motivate further design of novel photocatalysts with upconversion luminescence performance, which are applied to the removal of sulphonamide antibiotics in the environment.

An efficient sulfadiazine selection scheme for stable transformation in the model liverwort Marchantia polymorpha.

Plant macroevolutionary studies leverage the phylogenetic position of non-flowering model systems like the liverwort Marchantia polymorpha to investigate the origin and evolution of key plant processes. To date, most molecular genetic studies in Marchantia rely on hygromycin and/or chlorsulfuron herbicide resistance markers for the selection of stable transformants. Here, we used a sulfonamide-resistant dihydropteroate synthase (DHPS) gene to enable sulfadiazine-based transformation selection in M. polymorpha. We demonstrate the reliability of sulfadiazine selection on its own and in combination with existing hygromycin and chlorsulfuron selection schemes through transgene stacking experiments. The utility of this system is further demonstrated through confocal microscopy of a triple transgenic line carrying fluorescent proteins labelling the plasma membrane, cortical microtubules, and the nucleus. Collectively, our findings and resources broaden the capacity to genetically manipulate the increasingly popular model liverwort M. polymorpha.

Experimental data and modeling of sulfadiazine adsorption onto raw and modified clays from Tunisia.

In recent years, the increasing detection of emerging pollutants (particularly antibiotics, such as sulfonamides) in agricultural soils and water bodies has raised growing concern about related environmental and health problems. In the current research, sulfadiazine (SDZ) adsorption was studied for three raw and chemically modified clays. The experiments were carried out for increasing doses of the antibiotic (0, 1, 5, 10, 20, and 40 µmol L-1) at ambient temperature and natural pH with a contact time of 24 h. The eventual fitting to Freundlich, Langmuir and Linear adsorption models, as well as residual concentrations of antibiotics after adsorption, was assessed. The results obtained showed that one of the clays (HJ1) adsorbed more SDZ (reaching 99.9 % when 40 µmol L-1 of SDZ were added) than the other clay materials, followed by the acid-activated AM clay (which reached 99.4 % for the same SDZ concentration added). The adsorption of SDZ followed a linear adsorption isotherm, suggesting that hydrophobic interactions, rather than cation exchange, played a significant role in SDZ retention. Concerning the adsorption data, the best adjustment corresponded to the Freundlich model. The highest Freundlich KF scores were obtained for the AM acid-treated and raw HJ1 clays (606.051 and 312.969 Ln µmol1-n kg-1, respectively). The Freundlich n parameter ranged between 0.047 and 1.506. Regarding desorption, the highest value corresponded to the AM clay, being generally <10 % for raw clays, <8 % for base-activated clays, and <6 % for acid-activated clays. Chemical modifications contributed to improve the adsorption capacity of the AM clay, especially when the highest concentrations of the antibiotic were added. The results of this research can be considered relevant as regard environmental and public health assessment since they estimate the feasibility of three Tunisian clays in SDZ removal from aqueous solutions.

Azadirachta indica leaf extract based green-synthesized ZnO nanoparticles coated on spent tea waste activated carbon for pharmaceuticals and personal care products removal.

Pharmaceuticals and personal care products (PPCPs) are emerging contaminants in aqueous systems, posing threat to both human health and environment. In prior research, predominant focus has been on examining various adsorbents for removing PPCPs from single-pollutant systems. However, no study has delved into simultaneous adsorption of PPCPs multi-pollutant mixture. This study evaluates performance of Azadirachta indica leaf extract-based green-synthesized ZnO nanoparticles coated on spent tea waste activated carbon (ZTAC) for removing sulfadiazine (SZN) and acetaminophen (ACN). Adsorption investigations were conducted in single-component (ACN/SZN) and binary-component (ACN + SZN) systems. The synthesized ZTAC was characterized using SEM, XRD, FTIR, EDX, porosimetry and pHpzc analysis. The study examines impact of time (1-60 min), dose (0.2-4 g/L), pH (2-12) and PPCPs concentration (1-100 mg/L) on ACN and SZN removal. Various kinetic and isotherm models were employed to elucidate mechanisms involved in sorption of PPCPs. Furthermore, synergistic and antagonistic aspects of sorption process in multi-component system were investigated. ZTAC, characterized by its crystalline nature and surface area of 980.85 m2/g, exhibited maximum adsorption capacity of 47.39 mg/g for ACN and 34.01 mg/g for SZN under optimal conditions of 15 min, 3 g/L and pH 7. Langmuir isotherm and pseudo-second-order kinetic model best-fitted the experimental data indicating chemisorption mechanism. Removal of ACN and SZN on ZTAC demonstrated synergistic nature, signifying cooperative adsorption. Overall, valorization of ZTAC offers effective and efficient adsorbent for elimination of PPCPs from wastewater.

Exploring the influence of sulfadiazine-induced stress on antibiotic removal and transformation pathway using microalgae Chlorella sp.

Sulfadiazine (SDZ) is a kind of anti-degradable antibiotics that is commonly found in wastewater, but its removal mechanism and transformation pathway remain unclear in microalgal systems. This study investigated the effects of initial algae concentration and SDZ-induced stress on microalgal growth metabolism, SDZ removal efficiency, and transformation pathways during Chlorella sp. cultivation. Results showed that SDZ had an inhibitory effect on the growth of microalgae, and increasing the initial algal biomass could alleviate the inhibitory effect of SDZ. When the initial algal biomass of Chlorella sp. was increased to 0.25 g L-1, the SDZ removal rate could reach 53.27%-89.07%. The higher the initial algal biomass, the higher the SOD activity of microalgae, and the better the protective effect on microalgae, which was one of the reasons for the increase in SDZ removal efficiency. Meanwhile, SDZ stress causes changes in photosynthetic pigments, lipids, total sugars and protein content of Chlorella sp. in response to environmental changes. The main degradation mechanisms of SDZ by Chlorella sp. were biodegradation (37.82%) and photodegradation (23%). Most of the degradation products of SDZ were less toxic than the parent compound, and the green algae were highly susceptible to SDZ and its degradation products. The findings from this study offered valuable insights into the tradeoffs between accumulating microalgal biomass and antibiotic toxic risks during wastewater treatment, providing essential direction for the advancement in future research and full-scale application.

A novel alginate-embedded magnetic biochar-anoxygenic photosynthetic bacteria composite microspheres for multipollutant removal: Mechanisms of photo-bioelectrochemical enhancement and excellent reusability performance.

Existing wastewater treatment technologies face the key challenge of simultaneously removing emerging contaminants and nutrients from wastewater efficiently, with a simplified technological process and minimized operational costs. In this study, a novel alginate-embedded magnetic biochar-anoxygenic photosynthetic bacteria composite microspheres (CA-MBC-PSB microspheres) was prepared for efficient, cost-effective and one-step removal of antibiotics and NH4+-N from wastewater. Our results demonstrated that the CA-MBC-PSB microspheres removed 97.23% of sulfadiazine (SDZ) within 7 h and 91% of NH4+-N within 12 h, which were 21.23% and 38% higher than those achieved by pure calcium alginate-Rhodopseudomonas palustris microspheres (53% and 45.7%), respectively. The enhanced SDZ and NH4+-N removal were attributed to the enhanced photoheterotrophic metabolism and excretion of extracellular photosensitive active substances from R. Palustris through the photo-bioelectrochemical interaction between R. Palustris and magnetic biochar. The long-term pollutants removal performance of the CA-MBC-PSB microspheres was not deteriorated but continuously improved with increasing ruse cycles with a simultaneous removal efficiency of 99% for SDZ and 92% for NH4+-N after three cycles. The excellent stability and reusability were due to the fact that calcium alginate acts as an encapsulating agent preventing the loss and contamination of R. palustris biomass. The CA-MBC-PSB microspheres also exhibited excellent performance for simultaneous removal of SDZ (89% in 7 h) and NH4+-N (90.7% in 12 h) from the secondary effluent of wastewater treatment plant, indicating the stable and efficient performance of CA-MBC-PSB microspheres in practical wastewater treatment.

Insight in sulfadiazine degradation by peroxymonosulfate activated by polydopamine-derived nitrogen-doped carbon supported CoFe2O4: Co leaching inhibition and degradation enhancement.

Heterogeneous catalyst-mediated sulfate radical-based advanced oxidation processes (SR-AOPs) showed excellent performance during antibiotics degradation. Spinel was a promising catalyst for SR-AOPs, but the secondary contamination due to metal ions leaching needed to be addressed. And the destruction of catalyst structure could lead to the reduction of catalytic activity and the difficulty of recovery. Thus, a novel nitrogen-doped carbon (NC)-supported CoFe2O4 (CoFe2O4@NC) was synthesized as the activator of PMS for sulfadiazine (SDZ) degradation under low Co leaching conditions. The consequences indicated that the CoFe2O4@NC/PMS system exhibited higher PMS decomposition efficiency and reaction stoichiometry efficiency than the bare CoFe2O4/PMS systems (CoFe2O4-180 and CoFe2O4-800), which in turn demonstrated a better SDZ removal performance. Under the condition of CoFe2O4@NC dosage 0.1 g/L, PMS concentration 0.5 mM, solution pH 6.8 and temperature 25°C, SDZ (20 mg/L) was almost completely degraded within 60 min. XPS analysis showed that the NC not only protected and stabilized CoFe2O4, but also provided additional active sites for PMS activation. During SDZ degradation, SO4•-, HO•, •O2- and 1O2 were involved in the reaction, among which SO4• and HO• made the main contribution. Meanwhile, CoFe2O4@NC could be recovered by magnetic separation, and showed great stability (Co leaching 0.852 mg/L) and reusability. In the fifth cycle experiment, 85.02 % SDZ degradation was obtained. Based on the detected intermediates (12 intermediates were identified) and DFT calculations, possible degradation pathways for SDZ in CoFe2O4@NC/PMS were proposed. The condensed dual descriptor indicated that the N7, N11, and C15 atoms on SDZ molecule were the main sites of electrophilic attack, which was consistent with the detected intermediates. The degradation of SDZ involved hydroxylation of NH2, cleavage of S-N and extrusion of SO2. This study explored the improvements made in NC support material to catalytic performance and resistance to dissolution of spinel, providing new insights for subsequent researches.

The impact of an open-label design on human amniotic membranes vs. silver sulfadiazine dressings for second-degree burns: a randomized controlled clinical trial.

BACKGROUND: Burn wounds require optimal medical management due to associated psycho-emotional and socioeconomic impacts and severe pain. The use of synthetic and biological dressings improves healing and reduces burn wound complications. The present study aimed to compare the outcomes of using human amniotic membrane (hAM) dressings and conventional silver sulfadiazine (SSDZ) ointment dressings in the management of second-degree burn wounds. METHODS: Fifty patients who participated in this clinical trial were divided into two groups via simple randomization. All the enrolled patients, who had burnt in the last 24 h, had thermal damage mechanisms and were suffering from less than 20% second-degree heat-burn wounds on the skin surface. The target group (n = 25) was treated with hAM, and the control group (n = 25) was treated with SSDZ ointment. The researcher-designed checklist was used to determine the clinical performance in the follow-up assessments on days 7, 14, and 30. RESULTS: No significant differences were detected in terms of sex, age, or percentage of burn wounds (p > 0.05). Wound epithelialization at days 7, 14, and 30, scar formation, wound pigmentation, pain severity, analgesia requirements, and hospital stay length (on day 30) were significantly lower in the target group (treated with hAM) than in the control group (treated with SSDZ ointment) (p < 0.05). However, treatment costs in the target group ($170) were significantly higher than those in the control group ($71) (p < 0.001). CONCLUSION: Despite its higher cost, hAM, as a technology-based therapy dressing, demonstrates superiority over SSDZ ointment in terms of wound healing and pain management.

The healing effect of a mixture of Arnebia euchroma and animal fat on burn wounds in rats in comparison with sulfadiazine.

OBJECTIVE: Thermal burn is a serious cause of morbidity and mortality that affects millions of people worldwide. The aim of this experimental study was to investigate the efficacy of Arnebia euchroma (AE) to treat burn wounds in a rat model. METHOD: A total of 80 male rats (200-250g) were shaved over the back of the neck (2×3cm2) and a second-degree burn wound was induced at this site under general anaesthesia. The rats were then randomly assigned to one of four groups (each n=20) and the burns were treated daily for 14 days as follows: (1) dressed with animal fat; (2) dressed with sulfadiazine; (3) dressed with a mixture of AE and animal fat; (4) no treatment (control). Five rats from each group were sacrificed on days 3, 5, 9 and 14 post-burn and the wounds were evaluated histologically and immunohistochemically for the expression of interleukin (IL)-1 and IL-6. RESULTS: There was a significant increase at day 3 and decrease on day 5 samples for the expression of IL-1 in the AE plus fat group and IL-6 in the AE plus fat and sulfadiazine groups, compared to the control and fat treatment groups, respectively. Both AE plus fat and sulfadiazine treatments reduced inflammation and granulation tissue formation by day 5 post-burn, while re-epithelialisation commenced by day 9 post-burn. In addition, burns treated with AE plus fat exhibited keratinised epidermis, associated with regular collagen fibres, compared to moderately dense collagen fibres without vascularisation in the sulfadiazine group. CONCLUSION: These findings suggested that AE plus fat was superior to sulfadiazine in enhancing burn wound healing in rats.

Chemical stability and in vitro antimicrobial efficacy of diluted silver sulfadiazine powder and cream over a six-month period.

BACKGROUND: Silver sulfadiazine (SSD) is commonly formulated into otic preparations to treat otitis externa, although evidence of stability and antimicrobial efficacy with long-term storage is lacking. OBJECTIVES: To evaluate the effect of storage time on chemical stability and in vitro antimicrobial activity of SSD diluted in sterile water, including two 1% suspensions using SSD pharmaceutical-grade powder stored at room temperature (RT) in plastic or sterile glass bottles, and a 1:9 dilution using prescription SSD 1% cream stored at RT in a sterile glass bottle. MATERIALS AND METHODS: Liquid chromatography-tandem mass spectrometry (LC-MS/MS) assessed chemical stability. Trimethoprim/sulfamethoxazole-susceptible and trimethoprim/sulfamethoxazole-resistant strains of Staphylococcus pseudintermedius (SP), meticillin-resistant (MR) SP, S. schleiferi (SS), MRSS, Pseudomonas aeruginosa, Proteus mirabilis and Escherichia coli evaluated by 24 h time-kill analysis assessed in vitro antimicrobial efficacy. Each assessment was performed at zero, one, three and six months of storage. RESULTS: LC-MS/MS showed no significant change in concentration over time for any suspension. When adjusted for time and species/strain, all SSD suspensions showed significant reductions in colony forming units (cfu)/mL at 24 h (p < 0.001). Including all suspensions, a bactericidal effect (minimum 3-log cfu/mL reduction at 24 h) occurred against 94% of total isolates, with failure against 33 of 552 isolates (6%). Bactericidal failure was more likely with the cream-based suspension (p < 0.05) and at six months (p < 0.01). CONCLUSIONS AND CLINICAL RELEVANCE: Powder-based and cream-based SSD/sterile water suspensions showed no significant change in concentration and demonstrated in vitro antimicrobial activity for six months. Bactericidal failure was more likely with the cream-based suspension and after six months of storage.

Synthesis and Characterization of Sulfonamide-Containing Naphthalimides as Fluorescent Probes.

A tumor-targeting fluorescent probe has attracted increasing interest in fluorescent imaging for the noninvasive detection of cancers in recent years. Sulfonamide-containing naphthalimide derivatives (SN-2NI, SD-NI) were synthesized by the incorporation of N-butyl-4-ethyldiamino-1,8-naphthalene imide (NI) into sulfonamide (SN) and sulfadiazine (SD) as the tumor-targeting groups, respectively. These derivatives were further characterized by mass spectrometry (MS), nuclear magnetic resonance spectroscopy (1H NMR), Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible spectroscopy (UV), and a fluorescence assay. In vitro properties, including cell cytotoxicity and the cell uptake of tumor cells, were also evaluated. Sulfonamide-containing naphthalimide derivatives possessed low cell cytotoxicity to B16F10 melanoma cells. Moreover, SN-2NI and SD-NI can be taken up highly by B16F10 cells and then achieve good green fluorescent images in B16F10 cells. Therefore, sulfonamide-containing naphthalimide derivatives can be considered to be the potential probes used to target fluorescent imaging in tumors.

A highly sensitive and selective colorimetric aptasensor for detecting sulfadiazine in river waters based on gold nanoparticles synthesized from discarded Longan seed extract.

Gold nanoparticles (AuNPs) were extensively employed for in-situ detection sulfadiazine (SDZ) residues, yet current synthesis methods suffer from complex procedures, reagent pollution of the environment, and low particle quality. This study presents a novel synthesis method using discarded longan seed extract as a reducing agent to synthesized high-quality AuNPs, and then can be used for in-situ SDZ detection. Response surface methodology (RSM) was employed to optimize synthesis parameters, which resulted in five optimal combinations that enhanced the flexibility of synthesis. These AuNPs, ranging in size from 18.26 nm to 33.8 nm with zeta potentials from - 29.5 mV to - 14.3 mV, were successfully loaded with functional groups from longan seed extract. In the detection of SDZ, the colorimetric aptasensor demonstrated excellent sensitivity and selectivity over other antibiotics with a limit of detection and quantification at 70.98 ng·mL-1 and 236.59 ng·mL-1 in the concentration range of 200-800 ng·mL-1. Recoveries of spiked SDZ samples ranged from 97.90% to 106.7%, with RSD values below 9.25%. Meanwhile, the aptasensor exhibited exceptional diagnostic efficacy (AUC: 0.976) compared to UV absorption methods in the ROC evaluation. In conclusion, this study highlights the potential of using AuNPs synthesized from longan seed extract coupled with aptamer technology as a straightforward detection method for SDZ in river water, offering promising applications in environmental monitoring.

La3+@BC500-S2O82- system for removal of sulfonamide antibiotics in water.

Sulfonamide antibiotics (SAs) widely used have potentially negative effects on human beings and ecosystems. Adsorption and advanced oxidation methods have been extensively applied in SAs wastewater treatment. In this study, compared with Al3+@BC500 and Fe3+@BC500, La3+@BC500 for activating persulfate (S2O82-) had the best effect removal performance of sulfadiazine (SDZ) and sulfamethoxazole (SMX). Morphology, acidity, oxygen-containing functional groups, and loading of La3+@BC500 were analyzed by techniques, including EA, BET, XRD, XPS, FT-IR. XRD results show that with the increase of La3+ loading, the surface characteristics of biochar gradually changed from CaCO3 to LaCO3OH. Through EPR technology, it is proved that LaCO3OH on the surface of La3+@BC500 can not only activate S2O82- to generate SO4-•, but also to produce •OH. In the optimization experiment, the optimal dosage of La3+ is between 0.05 and 0.2 (mol/L)/g. SDZ had a good removal effect at pH (5-9), but SMX had a good removal effect only at pH=3. Zeta potential also proves that the material is more stable under acidic conditions. The removal process of SDZ is more in accord with pseudo-first-order kinetics (R2=0.9869), while SMX is more in line with pseudo-second order kinetics (R2=0.9926).

Mechanism of highly efficient electrochemical degradation of antibiotic sulfadiazine using a layer-by-layer GNPs/PbO2 electrode.

A PbO2 electrode integrating electrocatalytic and adsorptive functions was successfully fabricated by embedding layer-by-layer graphene nanoplatelets (GNPs) into ß-PbO2 active layer (GNPs/PbO2) and employed as anode for high-efficient removal of sulfadiazine (SDZ). In electrochemical degradation experiments, SDZ was quickly enriched on the surface of GNPs/PbO2 film via adsorption and then oxidized by ⋅OH in-site. In terms of the electrocatalytic performance and adsorption of electrode, the optimal electrodeposition time for each ß-PbO2 outer layer was 4 min (GNPs/PbO2-4). Compared with conventional PbO2 electrode, the layer-by-layer GNPs resulted in the smaller crystal size and denser surface of PbO2 electrode, thus facilitating the generation of active oxygen species. At the same time, the specific surface area, oxygen evolution potential (OEP) of the anode were enhanced and the charge-transfer resistance was reduced. For GNPs/PbO2-4 anode, the optimal conditions of electrochemical oxidation of SDZ were identified as initial pH 9, 50 mg/L of SDZ and 20 mA/cm2 of current density using response surface methodology (RSM), 98.15% of SDZ could be removed in this case. The contribution of radical oxidation and non-radical oxidation to SDZ removal was about 79% and 21%, respectively. Moreover, the reaction pathways of SDZ on the GNPs/PbO2-4 electrode involving hydroxylation, radical reaction and ring cleavage were speculated. Finally, the continuous SDZ degradation and accelerated service lifetime test suggested that the GNPs/PbO2-4 electrode was shown to be stable and repeatable, and the Pb2+ concentration was measured to ensure the safety of the treated solution. Consequently, the above findings provide an innovative way to design and prepare an effective and stable PbO2 electrode for electrochemical degradation of antibiotic wastewater.

Perioperative anaphylactic reactions to central venous and pulmonary artery catheters containing chlorhexidine, sulfadiazine, or latex: a historical cohort study.

PURPOSE: Central venous catheters (CVCs) and pulmonary artery catheters (PACs) containing chlorhexidine, silver sulfadiazine, or latex can cause perioperative anaphylaxis. We examined the incidence of and outcomes associated with anaphylaxis caused by CVCs/PACs. METHODS: In a historical cohort study, we retrospectively identified adult patients fitted with CVCs/PACs at the Mayo Clinics in Minnesota, Arizona, and Florida from 1 January 2008 to 1 March 2018. Potential and confirmed cases of perioperative anaphylactic reactions were individually reviewed and classified. RESULTS: During the study period, 39,505 procedures were performed during which CVCs/PACs were inserted. Of these, 2,937 patients with pre-existing chlorhexidine, sulfonamide (sulfa), and/or latex allergies had CVCs/PACs inserted that contained these substances. Perioperative anaphylaxis, in which CVCs/PACs were the confirmed or potential causative agent, occurred during 53 procedures. Seven patients had a preoperatively reported sulfa or latex allergy; no patients had a preoperative chlorhexidine allergy. Six of the seven patients with reported allergies to sulfa or latex had a CVC/PAC inserted that contained these substances. Twenty-four patients with anaphylaxis had postoperative allergic disease consultation; ten of these (42%) underwent skin testing. CONCLUSION: Perioperative anaphylactic reactions related to CVCs/PACs containing chlorhexidine, silver sulfadiazine, or latex were rare in this large historical cohort study. We identified 2,937 patients with pre-existing chlorhexidine, sulfa, and/or latex allergies and had CVCs/PACs inserted that contained these substances. Although few cases of perioperative anaphylaxis attributable to these substances were observed in patients with corresponding allergies, the potential for substantial complication exists. Providers should be aware of the potential for these hidden exposures.

RéSUMé: OBJECTIF: Les cathéters veineux centraux (CVC) et les cathéters artériels pulmonaires (CAP) contenant de la chlorhexidine, de la sulfadiazine argentique ou du latex peuvent provoquer une anaphylaxie périopératoire. Nous avons examiné l'incidence et les devenirs associés à l'anaphylaxie causée par les CVC/CAP. MéTHODE: Dans une étude de cohorte historique, nous avons identifié rétrospectivement des patients adultes chez lesquels un CVC/CAP avait été installé aux cliniques Mayo du Minnesota, de l'Arizona et de la Floride du 1er janvier 2008 au 1er mars 2018. Les cas potentiels et confirmés de réactions anaphylactiques périopératoires ont été examinés et classés individuellement. RéSULTATS: Au cours de la période à l'étude, 39 505 interventions ont été réalisées au cours desquelles des CVC/CAP ont été insérés. Parmi celles-ci, des CVC/CAP contenant de la chlorhexidine, des sulfamides et/ou du latex ont été insérés chez 2937 patients présentant des allergies préexistantes à ces substances. Une anaphylaxie périopératoire, dont l'agent causal confirmé ou potentiel était le CVC/CAP, s'est produite dans 53 interventions. Sept patients présentaient une allergie aux sulfamides ou au latex signalée avant l'opération; aucun patient n'a eu d'allergie préopératoire à la chlorhexidine. Un CVC/CAP contenant des sulfamides ou du latex a été inséré chez six des sept patients ayant signalé des allergies à ces substances. Vingt-quatre patients atteints d'anaphylaxie ont eu une consultation postopératoire pour une maladie allergique; dix d'entre eux (42 %) ont subi des tests cutanés. CONCLUSION: Les réactions anaphylactiques périopératoires liées aux CVC/CAP contenant de la chlorhexidine, de la sulfadiazine argentique ou du latex étaient rares dans cette vaste étude de cohorte historique. Nous avons identifié 2937 patients présentant des allergies préexistantes à la chlorhexidine, aux sulfamides et/ou au latex chez lesquels des CVC/CAP contenant ces substances ont été insérés. Bien que peu de cas d'anaphylaxie périopératoire attribuable à ces substances aient été observés chez des patients présentant des allergies correspondantes, il existe un risque de complication importante. Les fournisseurs doivent être conscients du potentiel de ces expositions cachées.

An Electrochemical Sensor for Sulfadiazine Determination Based on a Copper Nanoparticles/Molecularly Imprinted Overoxidized Polypyrrole Composite.

To protect consumers from risks related to overexposure to sulfadiazine, total residues of this antibacterial agent in animal-origin foodstuffs not exceed international regulations. To this end, a new electrochemical sensor based on a molecularly imprinted polymer nanocomposite using overoxidized polypyrrole and copper nanoparticles for the detection of sulfadiazine is elaborated. After optimization of the preparation of the electrochemical sensors, their differential pulse voltammetric signal exhibits an excellent stability and reproducibility at 1.05 V, with a large linear range between 10-9 and 10-5 mol L-1 and a low detection limit of 3.1 × 10-10 mol L-1. The produced sulfadiazine sensor was successfully tested in real milk samples. The combination of the properties of the electrical conduction of copper nanoparticles with the properties of the preconcentration of the molecularly imprinted overoxidized polypyrrole allows for the highly sensitive detection of sulfadiazine, even in real milk samples. This strategy is new and leads to the lowest detection limit yet achieved, compared to those of the previously published sulfadiazine electrochemical sensors.

The plasma and tissue kinetics of sulfadiazine and its metabolite in Ictalurus punctatus after oral gavage at two temperatures.

A plasma and tissue kinetic study of sulfadiazine (SDZ) and its metabolite, N4 -acetyl sulfadiazine (ACT-SDZ), was characterized in channel catfish (Ictalurus punctatus) following a single oral dose of 50 mg/kg at 18 and 24°C. Samples were collected at predetermined time points and determined by ultra-performance liquid chromatography. The classical one-compartmental method was used to estimate the pharmacokinetic parameters. Results showed that the changing of temperature was markedly influential on the kinetics of SDZ and ACT-SDZ in plasma and tissues. When the temperature was increased from 18 to 24°C, the elimination half-life (K10_HF) of SDZ was decreased in gill, kidney, and muscle + skin, but increased in liver and plasma. The K10_HF of ACT-SDZ also had a decreased trend in gill, liver, and plasma but had comparable values in kidney and muscle + skin. The absorption half-life (K01_HF), time to peak concentration (Tmax ), and area under concentration-time curve (AUC0-∞ ) of SDZ and ACT-SDZ all exhibited declined tendencies in plasma and tissues. The apparent volume of distribution (V_F) of SDZ in plasma was increased from 0.53 to 1.48 L/kg, and the apparent systemic total body clearance (Cl_F) was increased from 0.028 to 0.060 L/h/kg. In a word, K01_HF, Tmax , and AUC0-∞ of SDZ and ACT-SDZ were decreased in plasma and tissues with the increase of temperature, whereas the V_F and Cl_F of SDZ were increased. Meanwhile, we calculated the percentage of time profile of SDZ concentration more than minimum inhibitory concentration to total time (%T > MIC) to guide clinical usage of SDZ. When the dosage interval was 24 h, the values of %T > MIC were all >90% in plasma and most tissues. Therefore, we recommend an oral dose of SDZ at 50 mg/kg once per 24 h at 18-24°C against the fish pathogens with an MIC value of ≤6.4 µg/mL.

A Novel Strategy of Combined Pulsed Electro-Oxidation and Electrolysis for Degradation of Sulfadiazine.

A combination of the peroxymonosulfate (PMS) electro-activation process and the electro-oxidation process driven by a pulsed electric field (PEF) was used to degrade sulfadiazine (SND) wastewater. Mass transfer is the limiting step of electrochemical processes. The PEF could enhance mass transfer efficiency by reducing the polarization effect and increasing the instantaneous limiting current compared with the constant electric field (CEF), which could benefit the electro-generation of active radicals. The degradation rate of SND after 2 h was 73.08%. The experiments investigated the effects of operating parameters of pulsed power supply, PMS dosage, pH value and electrode inter distance on the degradation rate of SND. The predicted response value of single-factor performance experiments was obtained as 72.26% after 2 h, which was basically consistent with the experimental value. According to the quenching experiments and EPR tests, both SO4•- and •OH were present in the electrochemical processes. The generation of active species were significantly greater in the PEF system than that in the CEF system. Moreover, four kinds of intermediate products were detected during the degradation by LC-MS. This paper presents a new aspect for electrochemical degradation of sulfonamide antibiotics.

Acute radiation dermatitis among patients with nasopharyngeal carcinoma treated with proton beam therapy: Prognostic factors and treatment outcomes.

A high incidence of severe acute radiation dermatitis (ARD) has been reported for cancer patients treated by proton beam therapy (PBT). This observational study investigated the prognostic factors and treatment outcomes of ARD among patients with nasopharyngeal carcinoma (NPC) treated with PBT. Fifty-seven patients with newly diagnosed NPC and treated with PBT were enrolled. ARD was recorded weekly based on the criteria of Common Terminology Criteria for Adverse Events version 4.0 at treatment visits (1st to 7th weeks) and 1 week (8th week) and 1 month (11th week) after the completion of PBT. The maximum ARD grade was 1, 2, and 3 in 26 (45.6%), 24 (42.1%), and 7 (12.3%) of the patients, respectively. The peak incidence of grade 2 and 3 ARD was observed during the period of the 6th to 8th weeks. Treatment of ARD included topical corticosteroid alone in 24 (42.1%) patients, topical corticosteroid plus silver sulfadiazine in 33 (57.9%) patients, and non-adhering silicone dressing to cover severe skin wound area in 25 (43.8%) patients. In the 11th week, most grade 2 and 3 ARD had disappeared and 93.0% of the patients had ARD of grade 1 or lower. In the binary logistic regression model, we identified habitual smoking (odds ratio [OR]: 5.2, 95% confidence interval [CI]: 1.3-18.8, P = .012) and N2 to N3 nodal status (OR: 4.9, 95% CI: 1.6-15.4, P = .006) as independent predictors of grade 2 and 3 ARD. The results show ARD is a major concern for patients with NPC treated with PBT, especially those with habitual smoking or advanced nodal status. Topical corticosteroid, silver sulfadiazine, and non-adhering silicone dressing are effective for treating ARD induced by PBT.

Development and optimization of film forming non-pressurized liquid bandage for wound healing by Box-Behnken statistical design.

The goal of the current investigation was to develop a non-pressurized liquid bandage to promote the healing of wounds by using silver sulfadiazine. A three-factor three level box-behnken statistical design was employed to optimize the drug-loaded liquid bandage. Film-forming liquid bandage was developed by using ethyl-cellulose, dibutyl sebacate, and glycerol. For optimization, ethyl cellulose, dibutyl sebacate, and isopropyl myristate were taken as independent variables while tensile strength, water vapor absorption value, and drying time were taken as dependent variables. The film-forming liquid bandage was evaluated for various parameters like tensile strength, water vapor absorption value, drying time, viscosity, pH, in-vitro drug release studies, in-vivo wound healing studies, and stability studies. The optimized formulation was found with the tensile strength of 68.24 ± 0.24 MPa, water vapor absorption value of 2.00 ± 0.25 %, drying time of 1.75 ± 0.14 min, viscosity of 60 ± 0.5 cPs, pH of 6.0 ± 0.5 and good physicochemical properties with satisfactory film-forming ability. The in-vitro study shows that the release of test formulations was better than the marketed formulation. After 6 h of study, the liquid bandage and marketed formulation showed 41.02 % and 29.32 % of drug release respectively. Significant results were obtained for the in-vivo wound healing studies. Upon comparison with the control group (2.61 mm) and marketed formulation (1.44 mm), rats treated with the optimized formulation exhibited a noticeable improvement in wound contraction (0.8 mm). The liquid bandage after three months of stability testing was found to be stable with optimum. The film-forming liquid bandage was found to be an effective alternative to conventional topical preparations as it develops a thin polymeric layer on the wound and the skin around it and improves comfort for the patient by protecting the wound from external factors and physical harm.