亚甲蓝光化学法病毒灭活血浆外泌体微小RNA差异表达谱分析 / 中国生物制品学杂志

@#Objective To explore the effect of methylene blue photochemistry(MB-P)viral inactivation treatment on the expression of microRNA(miRNA)in plasma exosomes,in order to provide a new reference for the quality control of MB-P virus inactivated plasma. Methods Whole blood samples of 11 healthy volunteers were collected from July 2021 to April2022. Fresh plasma from the same person was prepared into two parts,fresh frozen plasma(FFP)and MB-P virus inactivated plasma,respectively. The plasma exosomes were isolated by differential centrifugation,and identified by transmission electron microscopy(TEM)and nanoparticle tracking analysis(NTA). Then the expression profiles of miRNA were detected by microarray technique. Furthermore,four differentially expressed miRNA were verified by qRT-PCR,the target genes of differentially expressed miRNA were predicted by bioinformatics methods,and GO function enrichment analysis and KEGG pathway enrichment analysis were performed on the differentially expressed genes. Results The morphological characteristics and diameters of the extracted vesicles of the two groups were consistent with the characteristics of exosomes. Compared with the control group,there were 14 differentially expressed miRNA in plasma exosomes of MB-P group,of which the expression of six miRNA was up-regulated and eight miRNA was down-regulated. The results of qRT-PCR were generally consistent with the expression trend of microarray. The target genes of differentially expressed miRNA were mainly involved in DNA binding,ion binding,catalytic activity and other functions,and participated in a variety of biological processes such as nucleic acid metabolism,biosynthesis,and transcription regulation. In addition,significantly enriched functional pathways were closely related to viral infectious diseases,tumors,PI3K-Akt signaling pathway,MAPK signaling pathway and so on.Conclusion The expression of exosome miRNA in MB-P virus inactivated plasma was different from that in FFP. The plasma exosome miRNA may be used as a potential reference for the quality evaluation of MB-P virus inactivated plasma.

Methylene blue alleviates dopaminergic neuronal pyroptosis to improve motor dysfunction in Parkinson's disease mouse models / 中华神经医学杂志

Objective:To investigate the effect of methylene blue (MB) on motor dysfunction and its mechanism in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced Parkinson's disease (PD) mouse models.Methods:Forty healthy male C57BL/6 mice were randomly divided into 4 groups: control group, model group, low-dose treatment group and medium-dose treatment group ( n=10); PD mouse models were established by intraperitoneal injection of 25 mg/kg/d MPTP for a consecutive 7 d; low-dose treatment group and medium-dose treatment group were pretreated intraperitoneally with MB 2 mg/kg/d or MB 10 mg/kg/d for a consecutive 3 d, respectively; and then, MPTP 25 mg/kg/d+MB 2 mg/kg/d or MPTP 25 mg/kg/d+MB 10 mg/kg/d were injected intraperitoneally into the low-dose treatment group or medium-dose treatment group for a consecutive 7 d (MPTP and MB were given at 12 h of interval). Eight d after modeling, open field experiment, pole climbing experiment and rod rotating experiment were carried out to evaluate the spontaneous movement, coordination, endurance and motor ability. And then, the mice were sacrificed; immunofluorescent staining was used to observe tyrosine hydroxylase (TH) expression in the substantia nigra; Western blotting was used to detect the expressions of TH, α-synuclein, nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain-containing 3 (NLRP3), apoptosis-associated speck-like protein containing a CARD (ASC), cleaved-Caspase-1 and Gasdermin D (GSDMD) in the striatum and substantia nigra of mice. Contents of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-18 in the substantia nigra and striatum of mice were detected by ELISA. Results:Compared with the control group, the model group had shortened residence time in rod rotating, prolonged descent time in rod climbing, reduced total movement distance in open field, decreased number of TH-positive cells in the substania nigra, decreased TH protein levels in the substania nigra and striatum, and increased NLRP3, ASC, cleaved-Caspase-1, GSDMD and GSDMD-N protein levels in the substania nigra and striatum, and increased TNF-α, IL-1β and IL-18 contents in the substania nigra and striatum, with significant differences ( P<0.05). Compared with the model group, low-dose treatment group and medium-dose treatment group had prolonged residence time in rod rotating, shortened descent time in rod climbing, increased total movement distance in open field, increased number of TH-positive cells in the substania nigra, and increased TH protein levels in the substania nigra and striatum, decreased NLRP3, ASC, and cleaved-Caspase-1 levels in the substania nigra and striatum, and decreased TNF-α, IL-1β and IL-18 contents in the substania nigra and striatum, with significant differences ( P<0.05). No statistical differences in the above indexes were noted between the low-dose treatment group and medium-dose treatment group ( P>0.05). Conclusion:Low-/medium-dose MB can ameliorate motor dysfunction in PD mouse models, whose mechanism may be related to downregulate NLRP3 inflammasome and inhibit neuroinflammatory response to reduce dopaminergic neuron pyroptosis.

Methylene blue as an adjuvant during cardiopulmonary resuscitation: an experimental study in rats

Abstract Introduction: Methylene Blue (MB) has been shown to attenuate oxidative, inflammatory, myocardial, and neurological lesions during ischemia-reperfusion and has great potential during cardiac arrest. This study aimed to determine the effects of MB combined with epinephrine during cardiac arrest on myocardial and cerebral lesions. Method: Thirty-eight male Wistar rats were randomly assigned to four groups: the sham group (SH, n = 5), and three groups subjected to cardiac arrest (n = 11 /group) and treated with EPI 20 μg.kg−1 (EPI), EPI 20 μg.kg−1 + MB 2 mg.kg−1 (EPI + MB), or saline 0.9% 0.2 ml (CTL). Ventricular fibrillation was induced by direct electrical stimulation in the right ventricle for 3 minutes, and anoxia was maintained for 5 minutes. Cardiopulmonary Resuscitation (CPR) consisted of medications, ventilation, chest compressions, and defibrillation. After returning to spontaneous circulation, animals were observed for four hours. Blood gas, troponin, oxidative stress, histology, and TUNEL staining measurements were analyzed. Groups were compared using generalized estimating equations. Results: No differences in the Returning of Spontaneous Circulation (ROSC) rate were observed among the groups (EPI: 63%, EPI + MB: 45%, CTL: 40%, p = 0.672). The mean arterial pressure immediately after ROSC was higher in the EPI+MB group than in the CTRL group (CTL: 30.5 [5.8], EPI: 63 [25.5], EPI+MB: 123 [31] mmHg, p = 0.007). Serum troponin levels were high in the CTL group (CTL: 130.1 [333.8], EPI: 3.70 [36.0], EPI +MB: 43.7 [116.31] ng/mL, p < 0.05). Conclusion: The coadministration of MB and epinephrine failed to yield enhancements in cardiac or brain lesions in a rodent model of cardiac arrest.

Intravital Microscopy Evidence That Methylene Blue Should Be a Vasopressor-Sparing Agent in Sepsis Vasoplegia

ABSTRACT Microvasculature failure is expected in sepsis and at higher amine concentrations. Therefore, special attention focused individually on microcirculation is needed. Here, we present that methylene blue can prevent leukocytes from adhering to the endothelium in a rat model of lipopolysaccharide-induced endotoxemia. As hypothesis evidence, an intravital microscopy image is presented.

Establishment and evaluation of HPLC-MS/MS method in determining serum H2S / 中国医学装备

Objective:To establish a determination method of high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS)for serum hydrogen sulfide(H2S),so as to determine serum H2S.Methods:This study collected serum samples of 30 patients who admitted to Beijing Jishuitan Hospital affiliated to Capital Medical University from April 2023 to May 2023,and they were divided into osteoporosis group and control group according to whether existed osteoporosis,with 15 cases in each group.HPLC-MS/MS and enzyme-linked immunosorbent assay were used respectively to determine serum H2S.And then,the precision,accuracy and correlation between the two methods were evaluated.Results:HPLC-MS/MS can fast detect the content of serum H2S through detecting methylene blue in the serum,which analysis time was only 1.5 minutes,and its specificity was higher.The relative standard deviation(RSD)value of quality control plasma was 8.77%,and that of quality control plasma with the standard and pure water with standard were respectively 4.58% and 8.23%.The precisions of them met the requirement of detection(less than 20%).The recovery was 103.5% through used the above data,and the accuracy accorded with the requirements of quantitative detection(recovery was 103.5%).Conclusion:HPLC-MS/MS method is rapid and accurate in detecting H2S,which can accurately detect the content of serum H2S.This method has a series of advantages include fast,high throughput,high sensitivity and favorable stability,which contributes to conduct basic research of the content of serum H2S in the cellular pathways of human.

Improved effect and underlying mechanism of methylene blue on cognitive function in brain-inflammatory-aging rats / 中华老年心脑血管病杂志

Objective To determine the improved effect of methylene blue(MB)on cognitive func-tion in brain-inflammatory-aging rats and investigate the underlying mechanism.Methods A total of 38 healthy 12-month-old SD rats were randomly divided into healthy control group,lipopo-lysaccharide(LPS)group,MB vehicle group and MB group,with 8 rats in the control and 10 rats in the other three groups.LPS was injected into the fourth ventricle with aid of a subcutaneous sustained release pump to establish a rat model of brain chronic inflammatory aging.MB of 0.5 mg/(kg·d)was added into the pump in the rats from the MB group.T-maze test and new object recognition test were employed to evaluate the learning and memory abilities of the rats.The acti-vation of microglia and astrocytes in the hippocampal CA1 region of the rats was detected by im-munofluorescence assay.The release of inflammatory factors IL-1β and IL-6 was measured by ELISA,and neuronal death in the CA1 region was assessed by neuronal nuclei(NeuN)fluores-cence staining.Results There was no significant difference in the exploration time for new and old objects between the LPS group and the MB solvent group(P＞0.05).The MB group spent significantly longer time in exploring the new objects than the old object(22.50±4.32 s vs 11.60± 3.01 s,P=0.000).The alternating selection rate of new arm and expression level of NeuN antigen were significantly decreased,and the expression levels of ionized calcium binding adaptor mole-cule-1(Iba-1)and glial fibrillary acidic protein(GFAP)and the contents of IL-1β and IL-6 were obviously increased(P＜0.05)in the LPS group and the MB vehicle group than the healthy con-trol group.Compared with the MB vehicle group,the MB group had notably increased alternating selection rate of new arms and higher NeuN expression level,and decreased Iba-1 and GFAP ex-pression and IL-1β and IL-6 contents(P＜0.05).Conclusion Subcutaneous administration of MB could significantly inhibit the damages of spatial learning and memory abilities in the LPS-induced brain chronic inflammatory aging rats.The mechanism may be closely associated with MB inhibi-ting inflammatory glial cells and protecting hippocampal pyramidal neurons.

Azul de metileno, opción para la marcación de cáncer colorrectal pre procedimiento mínimamente invasivo. Reporte de caso

El cáncer colorrectal es una patología común que causa aproximadamente 861,000 muertes al año. Se presenta el caso de un paciente masculino de 50 años, con hipertensión arterial y Diabetes mellitus tipo II, con diagnóstico de neoplasia en colon descendente, al cual se le realizó procedimiento mínimamente invasivo, posterior a marcación tumoral con azul de metileno por medio de endoscopia de vías digestiva bajas. Postoperatorio adecuado, sin complicaciones. El tratamiento de elección para el cáncer colorrectal sin metástasis es la exeresis oncológica. Actualmente, el manejo quirúrgico recomendado es por medio de procedimiento mínimamente invasivo, sin embargo, es un desafío puesto que en algunos casos la identificación de la lesión es difícil y adicionalmente requiere una curva de aprendizaje pronunciada. Por lo anterior, utilizamos el azul de metileno para la marcación del tumor previo procedimiento, con excelentes resultados, sin complicaciones. La marcación tumoral con azul de metileno previa al procedimiento mínimamente invasivo es seguro, útil, económico y de bajo riesgo.

Colorectal cancer is a common pathology, causing approximately 861,000 deaths a year. The case a 50-year-old male patient, with arterial hypertension and type II diabetes mellitus, with a diagnosis of neoplasia in the descending colon, which was performed minimally invasive procedure, after tumor marking with methylene blue by means of endoscopy of lower digestive tracts. Adequate postoperative period, without complications. The treatment of choice for colorectal cancer without metastasis is oncological exeresis. Currently the recommended surgical management is by means of a minimally invasive procedure, however, it is a challenge since in some cases the identification of the lesion is difficult and additionally requires a pronounced learning curve. Therefore, we use methylene blue for the marking of the tumor after the procedure, with excellent results, without complications. Methylene blue tumor marking prior to the minimally invasive procedure is safe, useful, inexpensive, and low risk.

Use of Methylene Blue to Treat Vasoplegia Syndrome in Cystic Fibrosis Patients Undergoing Lung Transplantation: A Case Series

Background: Several studies have demonstrated the utility of methylene blue (MB) to treat vasoplegic syndrome (VS), but some have cautioned against its routine use in lung transplantation with only two cases described in prominent literature. Cystic fibrosis patients commonly have chronic infections which predispose them to a systemic inflammatory syndrome-like vasoplegic response during lung transplantation. We present 13 cystic fibrosis patients who underwent lung transplantation and received MB for vasoplegic syndrome while on cardiopulmonary bypass, with or without inhaled pulmonary vasodilator therapy. Methods: Single?center, retrospective, case series analysis of cystic fibrosis patients who underwent lung transplant and received MB for vasoplegia. We defined the primary outcome as 30-day mortality, and secondary outcomes as primary graft failure, 1-year mortality, postoperative complications, and hemodynamic response to MB. Results: MB was associated with a significant increase in mean arterial pressure (MAP) (P < 0.001) in all patients, and 84.6% (11/13) of the patients had either a decrease or no change in vasopressor requirement. No patients developed acute primary graft dysfunction and there was 100% 30?day and 1?year survival. One patient required Extracorporeal membrane oxygenation (ECMO) for hypoxemia and 69% (9/13) of the patients had evidence of postoperative right ventricular dysfunction, but no patients required a right ventricular assist device. Conclusion: This case series demonstrates the effectiveness of MB in treating vasoplegia in cystic fibrosis patients during lung transplantation, without evidence of primary graft dysfunction, 30?day or 1?year mortality. The safety of MB regarding hypoxemia and increased pulmonary vascular resistance requires further investigation.

Treatment of vascular paralysis syndrome with methylene blue during kidney transplantation: one case report / 中华器官移植杂志

The report described one case of vascular paralysis syndrome during kidney transplantation to provide references for clinical practice.After intraoperative opening of kidney artery and vein, the recipient developed vascular paralysis syndrome.However, the efficacy is not obvious after dosing of norepinephrine.After an intravenous infusion of methylene blue, the recipient has a successful removal of tracheal intubation and recovered well.

Analysis of chylemia and its impact on blood product quality / 中国输血杂志

【Objective】 To analyze the causes of chylemia, explore the effects of varying degrees of chylemia on subsequent blood products and the countermeasures. 【Methods】 The information of blood donors in the Central Blood Station of Xinjiang Production and Construction Corps from January 2018 to July 2022 were analyzed retrospectively, and the causes of fatty blood discarding was analyzed in terms of gender, age and times of donation. The effects of chylemia of control group, mild group, moderate group and severe group and corresponding gender and age on the hemolysis rate of suspended red blood cells(RBCs) at the end of storage and residual amount of methylene blue in the inactivated plasma were discussed. 【Results】 The incidence of chylemia in males(0.93%,84/9 047) was much higher than that in females(0.24%,9/3 781) (P<0. 05). The hemolysis rates of WBC-free suspended RBCs of mild, moderate and severe chylemia group at the end of storage(0. 19±0.08,0.28±0.06,0.66±0.25) were higher than that in control group(0.08±0.03), in males significantly higher than those in females(0.08±0.03 vs 0.06±0.02,0.21±0.09 vs 0.15±0.04,0.30±0.05 vs 0.24±0.07), in the age group of 18-30 years significantly lower than those in 31-41 years(0.07±0.02 vs 0.09±0.03) and ≥41 years(0.07±0.02 vs 0.09±0.03), P <0.05. The residual methylene blue in plasma with viral inactivation prepared from mild and moderate chylemia was significantly higher than that in control group(0.12±0.02,0.18±0.06 vs 0.06±0.02) (P<0.05). 【Conclusion】 Chylemia shall be monitored during the whole process of blood collection, and coutermeasures shall be taken to decrease the effects of chylemia on blood quality.

Inhibitory effect of methylene blue mediated photodynamic therapy combined with berberine on Porphyromonas gingivalis in vitro / 国际生物医学工程杂志

Objective:To investigate the in vitro inhibitory effect of methylene blue mediated photodynamic therapy (PDT) combined with berberine on Porphyromonas gingivalis (P.g). Methods:P.g was cultured until the middle to late log phase, and methylene blue was added to P.g suspension at different mass concentrations for 5 min, and a laser (wavelength 660 nm, power 140 mW/cm 2) was irradiated for 2 min to find the optimal concentration of methylene blue combined with the laser for in vitro inhibition of P.g. The effect of methylene blue mediated PDT on the in vitro inhibition of P.g and the effect of berberine on the growth curve of P.g were observed. The inhibitory effect of methylene blue mediated PDT and berberine on P.g was investigated by successive combined applications. The effect of methylene blue mediated PDT on P.g morphology was observed by scanning electron microscopy. The absorption peaks of each component were measured by ultraviolet spectrophotometer. Results:The best inhibition was achieved at a methylene blue mass concentration of 24.414 1 μg/ml under 660 nm laser excitation. The differences were statistically significant in both the methylene blue and PDT groups compared with the control group (all P<0.001). 0.05 mg/ml berberine had an inhibitory effect on the planktonic bacteria of P.g. After P.g was treated with methylene blue mediated PDT, the bacterial cell walls were crumpled into clusters. Compared with the control group, the number of colonies was reduced in the 0.05 mg/ml berberine group, and the difference was statistically significant ( P<0.01). The difference between the 0.05 mg/ml berberine + light group and the control group was not statistically significant ( P>0.05). When PDT was combined with berberine, there was a synergistic inhibitory effect on P.g. PDT followed by berberine shows a better inhibitory effect on bacteria, and the differences were statistically significant (all P<0.01). After the berberine treatment, the bacterial surface became smooth, and the length of the bacterial body increased compared with the control group. Conclusions:Methylene blue mediated PDT has an inhibitory effect on P.g. When combined with berberine, it has a synergistic inhibitory effect on P.g., and the inhibition effect is better when PDT is applied first and then berberine is applied in combination.

Evaluation of the effect of Matricaria recutita monotherapy or in combination with photodynamic therapy on tissue repair in the dorsum of the tongue of rats*

Abstract The search for treatments that accelerate the healing of lesions is of constant interest. Matricaria recutita (chamomile) is a plant with antimicrobial, anti-inflammatory, and healing properties, and antimicrobial Photodynamic Therapy (aPDT) eradicates microorganisms, which favors tissue repair. Objective This study aimed to evaluate the effect of the topical use of chamomile with or without aPDT on tissue repair in rats' tongues. Methodology A total of 75 male Wistar rats underwent standardized ulceration on the dorsum of the tongue using a punch of 5 mm diameter and were randomly allocated into the following groups: control (G1), chamomile fluid extract (G2), chamomile infusion (G3), aPDT (G4), and chamomile infusion + aPDT (G5). On the 3rd, 7th, and 14th days postoperatively, euthanasia was performed, and the ulcers were measured using calipers. The presence of edema, inflammatory infiltrate, cellularity, re-epithelialization, and characterization of total collagen were evaluated using sections stained with Hematoxylin and Eosin and Red Sirius. Histomorphometry analyses of the percentage of total collagen, the distance from the basal layer to the epithelial surface, and the thickness of the stratum corneum were performed. Descriptive (absolute/relative frequencies and modes) and exploratory analyses were performed. The associations between the groups and the presence of ulcers were analyzed with Fisher's exact test. All analyses were performed using the R program and statistical significance was set at p=0.05. Results The G2 positively modulated the exudative and proliferative phases of repair, both clinically (p<0.0001) and histologically, whether in descriptive or inferential analyses (p<0.05). The G3 showed a significant difference in clinical parameters compared with G1 (p<0.0001). The G4 and G5 did not positively modulate tissue repair. Conclusion The chamomile fluid extract showed better outcomes for tissue repair in the rat tongue.

Clinical application of transcatheter arterial methylene blue angiography in the localization of lower gastrointestinal arterial bleeding / 介入放射学杂志

Objective To evaluate the clinical application value of transcatheter arterial methylene blue angiography in the localization of lower gastrointestinal arterial bleeding.Methods Ten patients with lower gastrointestinal arterial bleeding received interventional celiac artery angiography.After the bleeding responsible arteries were identified,a microcatheter was super-selectively placed in the bleeding responsible artery.During surgical procedure,the methylene blue solution was injected through the microcatheter to display the bleeding segment of the intestinal tract,providing precise localization of the bleeding intestinal segment for surgical resection.Results Transcatheter arterial methylene blue angiography could clearly display the bleeding segment of the intestinal tract.The bleeding segments of the intestinal tract in the 10 patients were quickly and accurately removed.After surgery,the gastrointestinal bleeding stopped,and no surgery-related complications occurred.Conclusion Transcatheter arterial methylene blue angiography can accurately detect the arterial bleeding segment of the lower gastrointestinal tract,which provides precise localization for quickly removing the bleeding segment of intestinal tract,therefor,this technique is worthy of widespread clinical application.(J Intervent Radiol,2023,32:1230-1232)

Effect of low-power diode laser on infected root canals

Abstract This study evaluated the effect of photodynamic therapy (PDT) on infected root canals. Twenty-one human teeth were selected, and 18 were infected by E. faecalis for 60 days. The antimicrobial strategies tested were: G1. Root canal preparation (RCP) using Niquel-Titanium (NiTi) rotary instruments, 2.5% NaOCl, and final irrigation with 17% EDTA, followed by PDT with methylene blue photosensitizer and laser diode low power; G2. RCP using stainless steel files and the same irrigation and PDT protocols as G1; G3. Same RCP protocol as G1 without PDT; G4. Only irrigation with 2.5% NaOCl; G5. Same PDT protocol as G1 without RCP; G6. Negative control; G7. Positive control. Samples for microbiological tests were collected initially (S1), after RCP (S2), and after PDT (S3). Subsequently, the roots were sectioned and prepared for Scanning Electron Microscopy (SEM) analysis. Bacterial growth was analyzed according to the turbidity of the culture medium, followed by spectrophotometric optical density (nm). The effect of PDT on the dentinal structure was evaluated at magnifications 1,600X and 5,000X and described qualitatively. The Wilcoxon test was used for the comparisons from the same specimens, and the Mann-Whitney test was used to compare groups ((=5%). Bacteria were found in all experimental groups' microbiological samples (S1, S2 and S3). The optical density of culture media was lower in S2 than in S1 of G1, 2, 3, and 4 (p> 0.05). After PDT (S3) in G1 and 2, there was an additional reduction in optical density of the culture medium, respectively (p>0.05). In Group 5, the analysis of culture media at S2 revealed an increase in optical density compared to S1(p>0.05). In SEM images of G1, 2, and 5, dentin with melting and recrystallization areas were evidenced. After preparation of the root canal with the rotary system or manually associated with 2.5% NaOCl, PDT was not able to completely eliminate E. faecalis present in the root canal.

Resumo Este estudo avaliou o efeito da terapia fotodinâmica (PDT) em canais radiculares infectados com E. faecalis. Vinte e um dentes humanos extraídos foram selecionados, e 18 foram infectados por E. faecalis por 60 dias. As estratégias antimicrobianas testadas foram: G1. Preparo do canal radicular (PCR) com instrumentos rotatórios de NiTi, NaOCl 2,5% e irrigação final com EDTA 17%, seguido de PDT com fotossensibilizador azul de metileno e laser diodo de baixa potência; G2. PCR usando limas de aço inoxidável e os mesmos protocolos de irrigação e PDT do G1; G3. Protocolo de PCR similar que G1 sem PDT; G4. Somente irrigação com NaOCl 2,5%; G5. Protocolo similar ao G1, sem PCR; G6. Controle negativo; G7. Controle positivo. Amostras para exames microbiológicos foram coletadas inicialmente (S1), após PCR (S2) e após PDT (S3). Na sequência, as raízes foram seccionadas e preparadas para análise em microscopia eletrônica de varredura (MEV). O crescimento bacteriano foi analisado de acordo com a turbidez do meio de cultura seguida pela densidade óptica espectrofotométrica (nm). O efeito da PDT na estrutura dentinária foi avaliado em aumentos de 1.600X e 5.000X, e descrito qualitativamente. O teste de Wilcoxon foi utilizado para as comparações dos mesmos espécimes e o teste de Mann-Whitney para as comparações entre os grupos ((=5%). Bactérias foram encontradas em todos os grupos experimentais, e em todas as coletas microbiológicas (S1, S2 e S3). A densidade óptica dos meios de cultura foi menor em S2 do que em S1 de G1, 2, 3 e 4 (p>0,05). Após a PDT (S3) em G1 e 2, houve redução adicional na densidade óptica do meio de cultura de 90,0% e 92,0%, respectivamente (p>0,05). No Grupo 5, a análise dos meios de cultura em S2 revelou um aumento de 3,2% na densidade óptica em comparação com S1(p>0,05). Nas imagens de MEV do G1, 2 e 5 foram evidenciadas dentina com áreas de fusão e recristalização. O PDT utilizado após preparo do canal radicular com sistema rotatório ou manual, associado ao NaOCl 2,5%, não foi capaz de eliminar completamente o E. faecalis em biofilme maduro presente no canal radicular.

Indigo Carmine Hemodynamic Studies to Treat Vasoplegia Induced by Compound 48/80 in a Swine Model of Anaphylaxis

Abstract Introduction: There are many reasons to believe that the nitric oxide/guanosine 3'5' - cyclic monophosphate (or NO/cGMP) pathway on vasoplegic states is underestimated. To study indigo carmine (IC) as an alternative to methylene blue was the investigation rationale. Methods: The IC (3mg/kg intravenous infusion) study protocol included five experimental groups; 1) Control group — saline was injected at 0 and 10 minutes; 2) IC group — IC was injected at 0 and saline at 10 minutes; 3) compound 48/80 (C48/80) group — C48/80 was injected at 0 minute and saline at 10 minutes; 4) C48/80 + IC group — C48/80 was injected at 0 minute and IC at 10 minutes; and 5) IC + C48/80 group — IC was injected at 0 minute and C48/80 at 10 minutes. The studies were carried out by registering and measuring hemodynamic and blood gasometric parameters, including continuous cardiac output. Results: 1) The effects of the drugs (IC and C48/80) were more evident in the first 20 minutes of recording; 2) hypotensive responses were more pronounced in the C48/80 groups; 3) IC isolated or applied before C48/80 caused transient pulmonary hypertension; and 4) after the first 20 minutes, the pressure responses showed stability with apparent hypotension more pronounced in the C48/80 groups. Clinical observations showed significant hemodynamic instability and catastrophic anaphylactic reactions (agitation, pulmonary hypertension, severe bronchospasm, urticaria, high-intensity cyanosis, violent gastric hypersecretion, and ascites). Conclusion: A global results analysis showed differences between groups only in the first 20 minutes of the experiments.

Methylene blue treatment for moderate-to-severe cases of acute respiratory syndrome due to COVID-19 infection: clinical outcomes—a prospective study

Background: We studied the real-life experience with Methylene blue administration among the moderate and severe cases of acute respiratory distress syndrome due to Covid-19 infection with the standard of care. Materials and Methods: This study is a prospective, single-center study including 103 hospitalized patients conducted in a tertiary healthcare center from June 2020 to July 2021. The route of administration of Methylene blue was through nebulization (0.5 mL 0.5% solution of Methylene blue + 2.5 mL of distilled water) three times a day as long as the patient was admitted. An ampoule of 10 mL of Methylene blue with 90 mL of potable water through oxygen port was administered as long as they needed oxygen. About 2 mg/kg body weight of Methylene blue in 300 mL of N.S. over 3 h was given once a day for 5 days. Results: Approximately 103 patients were seen with a mean age of 56.49 years. The most prevalent comorbid condition was diabetes. The SpO2 improved by 7.827%. On post-Methylene blue administration, the serum ferritin, C-reactive protein, lactate dehydrogenase, and D-dimer were reduced in comparison to pre-Methylene blue administration. Also, the average total length of stay was 14 ± 4.20, 13 ± 5.66, and 14 ± 3.50 days in 26.78% of patients in intensive care unit, 17.51% of patients in high dependency unit, and 58.71% of patients in Covid general ward, respectively. About 86.4% of the patients recovered and got discharged post-Methylene blue administration. The all-cause mortality was 13.59%, which could be due to underlying comorbidities and complications of Covid-19 infections. Conclusion: Methylene blue administration accelerated recovery in our patients with moderate and severe Covid-19 disease by controlling the hyperimmune response. The clinical improvement was seen by decreased levels of inflammatory markers, improved oxygen saturation, reduced length of hospital stay, and clinical improvements. Methylene blue administered in nebulization form, through oxygen port, and through intravenous infusion in the dose of 2 mg/kg body weight for 5 days and improved patients’ recovery, so it can be considered as a therapeutic option in moderate and severe Covid-19 disease.

Determination of methylene blue release in plasma virus inactivation bag by fluorescence energy transfer method / 中国输血杂志

【Objective】 To establish a simple, economical and rapid method for the determination of methylene blue (MB) release in virus inactivation bag. 【Methods】 Based on the fluorescence energy transfer between MB and BSA-stabilized gold nanoclusters (BSA-AuNCs), the standard curve of MB determination was established by measuring the fluorescence quenching degree of MB to BSA-AuNCs in different concentrations to conduct the determination of MB release in virus inactivation bag. 【Results】 There was a good linear relationship between the MB concentration (cMB) and the fluorescence quenching degree of BSA-AuNCs[ (I0-I)/I0=0.018cMB+ 0.021(r=0.996)] when the fluorescence emission wavelength was about 620 nm and the cMB was in the range of (0.9-36) μmoL/L. The recovery of MB was 98.00% -101.95 % when applied to determine MB at high, medium, and low concentrations, the obtained intra-day variation coefficients were 0.73%, 0.81% and 0.77% respectively, and the obtained inter-day variation coefficients were 3.92%, 3.81%, and 4.73% respectively. There was no significant difference between the results measured by this method and those measured by combination of solid-phase extraction and spectrophotometry(P>0.05). 【Conclusion】 The fluorescence energy transfer method could achieve simple and rapid determination of MB release in virus inactivation bag with accurate and reliable results.

Methylene Blue to Neonatal Septic Shock treatment in neonate pigs,

Abstract Objective The authors design an animal model of neonatal sepsis to analyze the treatment of neonatal septic shock with Methylene Blue (MB) in a swine model. Methods The study design included twenty male newborn pigs divided into four groups: 1) The control group; 2) The sepsis group (induced with lipopolysaccharide); 3) The MB group, and 4) The MB-treated sepsis group. Septic shock was defined as Blood Pressure (BP) dropping 20% below the baseline value. Continuous Blood Pressure (BP), Nitric Oxide (NO) levels, cyclic Guanosine Monophosphate (cGMP), malondialdehyde acid, base excess, lactate, arterial blood gases, hematocrit, and echocardiography were analyzed. Results The BP of the sepsis group treated with MB showed a slight improvement in the first hour after treatment; however, a significant difference was not observed compared to the untreated sepsis group. Besides hemodynamic stability, the current study did not show symptomatic pulmonary hypertension, suggesting that MB was safe in neonates and children. An improvement in Base Excel (BE) levels after MB administration in septic animals may indicate a possible improvement in microcirculation. Conclusion The MB improved biomarkers related to septic shock prognosis, although an improvement in the blood levels could not be detected. MB might be a beneficial drug for hemodynamic instability in infants.

Progress in neonatal methemoglobinemia / 国际儿科学杂志

Neonatal methemoglobinemia is a rare disorder characterized by cyanosis and hypoxemia, which could be caused congenitally by cytochrome b5 reductase enzyme deficiency or hemoglobin M disease, and could be acquired by the exposure to lidocaine, nitrites and other drugs.Blood gas analysis is a simple and accessible way to detect methomoglobin.Methemoglobinemia is related to numerous diseases in neonates, including diarrhea, acidosis, late-onset sepsis.Methylene blue is an effective drug for decreasing MetHb levels.Other therapeutic options, such as vitamin C, N-acetylcysteine and vitamin B2, could also be useful.This article reviews the progress of neonatal methemoglobinemia.

An in vitro study on the clearance effect of oxygen-releasing photodynamic therapy on Enterococcus faecalis in the root canal / 口腔疾病防治

Objective@#To investigate the clearance effect of photodynamic therapy (PDT) with an oxygen-releasing photosensitizer methylene blue (MB) formula on Enterococcus faecalis in the root canal.@*Methods @# Groups were divided into the MB group and oxygen release MB group. Samples in the MB group were mixed with 50 μmol/L MB solution, and samples in the oxygen release MB group were mixed with 50 μmol/L MB in oxygen release emulsion. N-acetyl-L-tryptophan amide (NATA) and 1,3-diphenylisobenzofuran (DPBF) were used to detect the oxidative activity and singlet oxygen generation of different formulas of MB (MB group, oxygen-releasing MB group), and the oxygen-releasing capacity of the oxygen-releasing photosensitizer formula was analyzed. The single root canal anterior teeth were collected, and the Enterococcus faecalis root canal infection model of isolated teeth was constructed. The distribution of Enterococcus faecalis in the root canal was observed by scanning electron microscopy. The isolated teeth with Enterococcus faecalis root canal infection were divided into three groups: the conventional root canal therapy group, MB-PDT therapy group, and oxygen-releasing MB-PDT therapy group, with 10 teeth in each group. Bacterial samples in the root canals of each group were obtained, the number of colonies was analyzed(CFU/mL) after 24 h of in vitro culture, and the clearance rate of Enterococcus faecalis in the root canal by photodynamic therapy was evaluated. The remaining isolated teeth with Enterococcus faecalis root canal infection were divided into 3 groups, with 5 samples in each group. Bacterial samples at a depth of 1 000 μm in the dentin tubules of the upper root, middle root and lower root segment were obtained and cultured in vitro for 24 h for calculations. The number of colonies (CFU/mL) was analyzed, and the clearance rate of Enterococcus faecalis in the dentin tubules of different segments of the root canals in each group was analyzed. @*Results @#The oxidation activity and singlet oxygen generation capacity in the oxygen-releasing MB group were stronger than those in the MB group. Scanning electron microscope detection showed that Enterococcus faecalis was distributed in dentinal tubules, indicating that the model of root canal infection in vitro was successfully constructed. The clearance rate of Enterococcus faecalis in the oxygen-releasing MB-PDT therapy group was higher than that in the conventional therapy group and the MB-PDT therapy group (P<0.05). Oxygen-releasing PDT significantly improved the bactericidal effect in the lower dentinal tubules, and the clearance rate of Enterococcus faecalis was better than in the other two groups (P<0.05).@*Conclusion@#Photodynamic therapy with the oxygen-releasing photosensitizer MB can achieve a better root canal bactericidal effect and can significantly improve the clearance effect of Enterococcus faecalis in the deep dentin of the lower root segment.