The impact of chitosan in experimental resin with different photoinitiator systems.

OBJECTIVE: to investigate the effect of different concentrations of chitosan added to experimental resins containing either BAPO or camphorquinone (CQ) as photoinitiators, regarding degree of conversion (DC), flexural strength (FS), flexural elastic modulus (E), Knoop microhardness (KHN), cytotoxicity, genotoxicity and antimicrobial activity. METHODS: Experimental resins with polymeric matrix of BisGMA and TEGDMA was added either 0.5 wt% BAPO or 0.5 wt% camphorquinone/0.2% amine along with and chitosan concentrations of 0.5%; 1.0% or 2.0%. Degree of conversion was measured using Fourier transformed infrared spectroscopy. Flexural strength and elastic modulus were obtained through three-point bending test and Knoop microhardness was measured in a microidenter. Direct cytotoxicity was performed in human keratinocytes and genotoxicity test was done in murine macrophages cells. Antimicrobial activity was acessed against Staphylococcus aureus and Streptococcus mutans through the inhibition halo. Data were analyzed using two-way ANOVA and Tukey teste (α = 0.05). RESULTS: The materials containing photoinitiator BAPO showed higher values of DC, FS, E, and KHN compared to resins with CQ. The addition of chitosan did not affect the properties of these materials. However, in resins containing CQ, the addition of chitosan improve these properties compared to control group. For the groups containing BAPO the chitosan reduced cytotoxicity and genotoxicity compared to materials with camphorquinone. The materials with 1.0% and 2.0% chitosan showed increased antibacterial activity in the materials containing BAPO as photoinitiator for both bacteria. SIGNIFICANCE: The alternative photoinitiator BAPO and chitosan can improve physical and biological properties of photoactivated resins when compared with the materials with photoinitiator camphorquinone.

Factors associated with adverse outcomes among patients hospitalized at a COVID-19 treatment center in Herat, Afghanistan.

Though many studies on COVID have been published to date, data on COVID-19 epidemiology, symptoms, risk factors and severity in low- and middle-income countries (LMICS), such as Afghanistan are sparse. To describe clinical characteristics, severity, and outcomes of patients hospitalized in the MSF COVID-19 treatment center (CTC) in Herat, Afghanistan and to assess risk factors associated with severe outcomes. 1113 patients were included in this observational study between June 2020 and April 2022. Descriptive analysis was performed on clinical characteristics, complications, and outcomes of patients. Univariate description by Cox regression to identify risk factors for an adverse outcome was performed. Adverse outcome was defined as death or transfer to a level 3 intensive care located at another health facility. Finally, factors identified were included in a multivariate Cox survival analysis. A total of 165 patients (14.8%) suffered from a severe disease course, with a median time of 6 days (interquartile range: 2-11 days) from admission to adverse outcome. In our multivariate model, we identified male gender, age over 50, high O2 flow administered during admission, lymphopenia, anemia and O2 saturation < = 93% during the first three days of admission as predictors for a severe disease course (p<0.05). Our analysis concluded in a relatively low rate of adverse outcomes of 14.8%. This is possibly related to the fact that the resources at an MSF-led facility are higher, in terms of human resources as well as supply of drugs and biomedical equipment, including oxygen therapy devices, compared to local hospitals. Predictors for severe disease outcomes were found to be comparable to other settings.

Effect of accelerated stability on the physical, chemical, and mechanical properties of experimental bleaching gels containing different bioadhesive polymers.

OBJECTIVE: To evaluate the physical-chemical (weight, pH, quantification of hydrogen peroxide) and mechanical (texture profile and rheology tests) properties of the experimental bleaching gel based on the bioadhesive polymer Aristoflex® AVC, after accelerated stability testing. MATERIALS AND METHODS: A total of 300 syringes of bleaching gels were divided into 5 groups (n = 60): Whiteness Perfect® 10%-FGM (WP); carbamide peroxide 10% with aristoflex (CPa); carbamide peroxide 10% with Carbopol (CPc); aristoflex thickener (A); and Carbopol thickener (C). According to the following requirements and time, the accelerated stability test was performed: in an incubator at 40 °C and 75% humidity per 1, 3, and 6 months, and baseline (refrigerator at 5 °C and 25% humidity). The variables were analyzed following the statistical tests: Two-way ANOVA and Tukey's test were applied to pH; weight data were analyzed using a mixed model for repeated measurements over time and the Tukey-Kramer test; one-way ANOVA and Tukey's test analyzed the rheology test; generalized linear models were used to quantify the peroxide amount and texture profile data. A significance level of 5% was considered. RESULTS: The experimental bleaches CPa and CPc had the highest pH values when compared to the others in 6 months. Thickeners A and C did not change the pH, weight, and active content over the accelerated stability times (p > 0.05). Furthermore, there was weight loss after 3 months of storage for CPa and CPc (p < 0.05). In the quantification of hydrogen peroxide, the WP group showed the highest values over time (p < 0.0001), only showing a significant loss after the 3rd month. Meanwhile, CPa and CPc showed a reduction in quantification from the 1st month. CONCLUSIONS: Temperature and humidity directly influenced the active content and properties of bleaching gels. In addition, the presence of components regardless of thickeners, such as stabilizers, in the commercial gel allowed for greater stability over time. CLINICAL RELEVANCE: The development of experimental bleaching gels for clinical use requires careful testing. Therefore, accelerated stability testing represents a valuable tool in the development and evaluation of cosmetic formulations.

Mucoadhesive, Thermoreversible Hydrogel, Containing Tetracaine-Loaded Nanostructured Lipid Carriers for Topical, Intranasal Needle-Free Anesthesia.

Recent advances have been reported for needle-free local anesthesia in maxillary teeth by administering a nasal spray of tetracaine (TTC) and oxymetazoline, without causing pain, fear, and stress. This work aimed to assess whether a TTC-loaded hybrid system could reduce cytotoxicity, promote sustained permeation, and increase the anesthetic efficacy of TTC for safe, effective, painless, and prolonged analgesia of the maxillary teeth in dental procedures. The hybrid system based on TTC (4%) encapsulated in nanostructured lipid carriers (NLC) and incorporated into a thermoreversible hydrogel of poloxamer 407 (TTCNLC-HG4%) displayed desirable rheological, mechanical, and mucoadhesive properties for topical application in the nasal cavity. Compared to control formulations, the use of TTCNLC-HG4% slowed in vitro permeation of the anesthetic across the nasal mucosa, maintained cytotoxicity against neuroblastoma cells, and provided a three-fold increase in analgesia duration, as observed using the tail-flick test in mice. The results obtained here open up perspectives for future clinical evaluation of the thermoreversible hybrid hydrogel, which contains TTC-loaded NLC, with the aim of creating an effective, topical, intranasal, needle-free anesthesia for use in dentistry.

Combining urine antigen and blood polymerase chain reaction for the diagnosis of disseminated histoplasmosis in hospitalized patients with advanced HIV disease.

Disseminated histoplasmosis (DH) is endemic in Latin America and the Caribbean where diagnostic tools are restricted. We carried-out a 1-year prospective cohort study at a referral hospital in São Paulo, Brazil. Participants had > or =18 years old, were hospitalized due to any indication and had CD4+ < 200 cells/µl. A urine commercial monoclonal Histoplasma galactomannan enzyme-linked immunosorbent assay (IMMY, Norman, OK, USA) and 'in house' Histoplasma blood nested PCR were performed in all cases. Probable/proven DH cases were defined according to international guidelines. Conventional mycological methods were available in routine conditions to investigate suspected DH cases. Treatment of participants followed the institutional routine. One-hundred six participants were included. Median age (interquartile range [IQR]) was 39.5 years (30.0-47.3) and 80 individuals (75.5%) were males. Median (IQR) CD4 cell count was 26.5 (9.4-89.3) cells/mm3. DH was diagnosed in 8/106 patients (7.5%). Antigen assay and/or PCR were positive in 4.7% (5/106) of patients. The antigen assay and/or PCR identified 37.5% (3/8) of DH cases, which had not been diagnosed with conventional mycological methods, but had clinical manifestations compatible with HD. In conclusion, the use of Histoplasma urine antigen and Histoplasma blood PCR guided by CD4 status contributed to the diagnosis of DH in hospitalized individuals. These assays were complementary to conventional mycologic methods and are urgently needed in our setting. LAY SUMMARY: In this prospective cohort study carried-out in a referral center in São Paulo, Brazil, we found a high frequency of AIDS-related disseminated histoplasmosis (8/106, 7.5%). We used urine antigen test and blood PCR assay to improve the diagnosis of this opportunistic disease.

Resistivity Technique for the Evaluation of the Integrity of Buccal and Esophageal Epithelium Mucosa for In Vitro Permeation Studies: Swine Buccal and Esophageal Mucosa Barrier Models.

Permeation assays are important for the development of topical formulations applied on buccal mucosa. Swine buccal and esophageal epithelia are usually used as barriers for these assays, while frozen epithelia have been used to optimize the experimental setup. However, there is no consensus on these methods. In transdermal studies, barrier integrity has been evaluated by measuring electrical resistance (ER) across the skin, which has been demonstrated to be a simple, fast, safe, and cost-effective method. Therefore, the aims here were to investigate whether ER might also be an effective method to evaluate buccal and esophageal epithelium mucosa integrity for in vitro permeation studies, and to establish a cut-off ER value for each epithelium mucosa model. We further investigated whether buccal epithelium could be substituted by esophageal epithelium in transbuccal permeation studies, and whether their permeability and integrity were affected by freezing at -20 °C for 3 weeks. Fresh and frozen swine buccal and esophageal epithelia were mounted in Franz diffusion cells and were then submitted to ER measurement. Permeation assays were performed using lidocaine hydrochloride as a hydrophilic drug model. ER was shown to be a reliable method for evaluating esophageal and buccal epithelia. The esophageal epithelium presented higher permeability compared to the buccal epithelium. For both epithelia, freezing and storage led to decreased electrical resistivity and increased permeability. We conclude that ER may be safely used to confirm tissue integrity when it is equal to or above 3 kΩ for fresh esophageal mucosa, but not for buccal epithelium mucosa. However, the use of esophageal epithelium in in vitro transmucosal studies could overestimate the absorption of hydrophilic drugs. In addition, fresh samples are recommended for these experiments, especially when hydrophilic drugs are involved.

Promising potential of articaine-loaded poly(epsilon-caprolactone) nanocapules for intraoral topical anesthesia.

To determine whether the permeation capacity and analgesic efficacy of articaine (ATC) could be increased and cytotoxicity decreased by encapsulation in poly(ɛ-caprolactone) nanocapsules (ATCnano), aiming at local or topical anesthesia in dentistry. Cellular viability was evaluated (using the MTT test and fluorescence microscopy) after 1 h and 24 h exposure of HaCaT cells to ATC, ATCnano, ATC with epinephrine (ATCepi), and ATC in nanocapsules with epinephrine (ATCnanoepi). The profiles of permeation of 2% ATC and 2% ATCnano across swine esophageal epithelium were determined using Franz-type vertical diffusion cells. Analgesic efficacy was evaluated with a von Frey anesthesiometer in a postoperative pain model in rats, comparing the 2% ATC, 2% ATCnano, 2% ATCepi, and 2% ATCnanoepi formulations to 4% ATCepi (a commercially available formulation). We show that use of the nanocapsules decreased the toxicity of articaine (P<0.0001) and increased its flux (P = 0.0007). The 2% ATCepi and 4% ATCepi formulations provided higher analgesia success and duration (P<0.05), compared to 2% ATC, 2% ATCnano, and 2% ATCnanoepi. Articaine-loaded poly(ɛ-caprolactone) nanocapsules constitute a promising formulation for intraoral topical anesthesia (prior to local anesthetic injection), although it is not effective when injected in inflamed tissues for pain control, such as irreversible pulpitis.

Hybrid nanofilms as topical anesthetics for pain-free procedures in dentistry.

Topical anesthetics are widely applied in order to relieve the discomfort and anxiety caused by needle insertion and other painful superficial interventions at the oral cavity. So far, there are no commercially available effective topical anesthetic formulations for that purpose, and the most of developments are related to hydrophilic and low mucoadhesive forms. Therefore, we have prepared different hybrid nanofilms composed of biopolymer matrices (chitosan, pectin, and chitosan-pectin) blended with nanostructured lipid carriers (NLC) loading the eutectic mixture of 5% lidocaine-prilocaine (LDC-PLC), in order to fulfill this gap in the market. These dual systems were processed as hybrid nanofilms by the solvent/casting method, and its mucoadhesive, structural and mechanical properties were detailed. The most appropriate hybrid nanofilm combined the advantages of both pectin (PCT) and NLC components. The resultant material presented sustained LDC-PLC release profile for more than 8 h; permeation across porcine buccal mucosa almost twice higher than control and non-cytotoxicity against 3T3 and HACAT cell lines. Then, the in vivo efficacy of PCT/NLC formulation was compared to biopolymer film and commercial drug, exhibiting the longest-lasting anesthetic effect (> 7 h), assessed by tail flick test in mice. These pectin-based hybrid nanofilms open perspectives for clinical trials and applications beyond Dentistry.

Palatal needle-free anesthesia for upper molars extraction. A randomized clinical trial.

BACKGROUND: The aim of this study was to compare the ability of liposomal and non-liposomal lidocaine and prilocaine in hydrogel formulations to promote topical anesthesia in palatal mucosa during upper molar extractions. METHODS: In this randomized, cross over, triple-blinded clinical trial, a liposomal and a non-liposomal formulation of the eutectic mixture of local anesthetics, 2.5% lidocaine and 2.5% prilocaine, were used to promote palatal anesthesia without the local anesthetic infiltration during bilateral upper molars extractions. RESULTS: From the total of 40 patients included in this study, the non-liposomal eutectic lidocaine-prilocaine formulation failed in 40% of cases, unlike the liposomal formulation, which was effective for all patients (Fisher's exact test, p < 0.0001). Furthermore, the liposomal formulation (26.75 ± 7,47 min) induced longer anesthesia duration (t-test, p < 0.0001) than the non-liposomal formulation (16.78 ± 4.75 min). No mucosal ulceration or discomfort was reported for both formulations. CONCLUSION: The liposomal formulation was able to induce adequate anesthesia in palatal mucosa during dental extraction, avoiding the local anesthetic infiltration. For the first time, a topical formulation allowed upper molars surgical removal without injection of any local anesthetic agent into palatal mucosa in adults.

Full-Thickness Intraoral Mucosa Barrier Models for In Vitro Drug-Permeation Studies Using Microneedles.

The use of permeation enhancers such as microneedles (MNs) to increase drug penetration across intraoral mucosa has increased in recent years. Permeation studies, commonly performed using vertical diffusion cells, are a well-established way to preview formulations and enhance their performance during the development stage. However, to our knowledge, the existing intraoral mucosa barrier models do not permit permeation using MN-pretreated mucosa due to their insufficient thickness. Therefore, the objective of this study was to develop a barrier model using thick palate tissues to perform in vitro permeation studies, with physical enhancement of the permeability of intraoral mucosa by pretreatment with MNs. The adapted Franz-type cells used in the permeation experiments were validated (cell dimensions and volume, sealing effectiveness, stirring and dissolution efficiency, temperature control, and establishment of uniaxial flux). Commercially available MNs were used in the palatal mucosa. Optical images of the mucosa were acquired to analyze the microperforations created. In vitro permeation studies were conducted with the MN-pretreated mucosa. This work presents a new in vitro method for the evaluation of MNs as permeation enhancers, with the aim of improving the absorption of drug formulations topically applied within the oral cavity.

Hybrid Hydrogel Composed of Polymeric Nanocapsules Co-Loading Lidocaine and Prilocaine for Topical Intraoral Anesthesia.

This study reports the development of nanostructured hydrogels for the sustained release of the eutectic mixture of lidocaine and prilocaine (both at 2.5%) for intraoral topical use. The local anesthetics, free or encapsulated in poly(ε-caprolactone) nanocapsules, were incorporated into CARBOPOL hydrogel. The nanoparticle suspensions were characterized in vitro in terms of particle size, polydispersity, and surface charge, using dynamic light scattering measurements. The nanoparticle concentrations were determined by nanoparticle tracking analysis. Evaluation was made of physicochemical stability, structural features, encapsulation efficiency, and in vitro release kinetics. The CARBOPOL hydrogels were submitted to rheological, accelerated stability, and in vitro release tests, as well as determination of mechanical and mucoadhesive properties, in vitro cytotoxicity towards FGH and HaCaT cells, and in vitro permeation across buccal and palatal mucosa. Anesthetic efficacy was evaluated using Wistar rats. Nanocapsules were successfully developed that presented desirable physicochemical properties and a sustained release profile. The hydrogel formulations were stable for up to 6 months under critical conditions and exhibited non-Newtonian pseudoplastic flows, satisfactory mucoadhesive strength, non-cytotoxicity, and slow permeation across oral mucosa. In vivo assays revealed higher anesthetic efficacy in tail-flick tests, compared to a commercially available product. In conclusion, the proposed hydrogel has potential for provision of effective and longer-lasting superficial anesthesia at oral mucosa during medical and dental procedures. These results open perspectives for future clinical trials.

Effects of lidocaine and the inclusion complex with 2-hydroxypropyl-ß-cyclodextrin on cell viability and proliferation of oral squamous cell carcinoma.

OBJECTIVES: Squamous cell carcinoma (SCC) is a malignant disease that affects the oral cavity. Lidocaine has shown antiproliferative and cytotoxic activity on several cell types. The rapid dispersion is a limitation issue; however, the complexation in cyclodextrin improved pharmacological features and modified the drug release. This study investigated the effects of lidocaine (lido) complexed with 2-hydroxypropyl-ß-cyclodextrin (HP-ß-CD-lido) on cell viability and proliferation of human tongue squamous cell carcinoma SCC9 and SCC25. METHODS: The complex formation was confirmed by differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). Cells SCC9 and SCC25 were exposed to lido and HP-ß-CD-lido (40-4000 µm), and the effects on cell viability (MTT) and antiproliferative activity (SRB) were tested. KEY FINDINGS: Differential scanning calorimetry and SEM results demonstrated the occurrence of host-guest interaction. Lido and HP-ß-CD-lido (4000 µm) significantly reduced the viability of SCC9 cells to 83% and 63%, respectively. The viability of SCC25 treated with lido, and HP-ß-CD-lido (4000 µm) was 71% and 44%, respectively. Lido (4000 µm) reduced the proliferation of SCC9 and SCC25 to 39.5% and 23.7%, respectively. HP-ß-CD-lido (4000 µm) was cytotoxic for both cell lines. CONCLUSIONS: HP-ß-CD was able to potentiate the in vitro cytotoxic effects of lidocaine on human squamous cell carcinoma.

Antimicrobial Activity of Two Garlic Species (Allium Sativum and A. Tuberosum) Against Staphylococci Infection. In Vivo Study in Rats.

Purpose: This study observed the effect of garlic extracts and amoxicillin against an induced staphylococcal infection model. MIC and MBC were also obtained for aqueous extracts of Allium sativum (Asa) and Allium tuberosum (Atu) against Staphylococcus aureus penicillin-sensitive (PSSA - ATCC 25923) and MRSA (ATCC 33592). Methods: Granulation tissues were induced in the back of 205 rats. After 14 days, 0.5 mL of 108 CFU/mL of PSSA or MRSA were injected inside tissues. After 24h, animals were divided: G1 (Control) - 0.5 mL of NaCl 0.9%; G2 - Asa 100 mg/kg or 400mg/kg; G3 - Atu 100 mg/kg or 400 mg/kg; G4 - amoxicillin suspension 50 mg/kg, considering PSSA infection; and G5 (Control) - 0.5 mL of NaCl 0.9%; G6 - Asa 400mg/kg; G7 - amoxicillin 50 mg/kg; and G8 - Asa 400 mg/kg + amoxicillin 50 mg/kg for MRSA. All treatments were administered P.O. every 6h. Animals were killed at 0, 6, 12 and 24h. Samples were spread on salt-mannitol agar. Colonies were counted after 18 h at 37 °C. Atu was not able to inhibit or kill PSSA and MRSA. Considering Asa, MIC and MBC against PSSA were 2 mg/mL and 4 mg/mL, respectively; and 16 mg/mL and 64 mg/mL against MRSA. Results: No effect was observed in vivo for control, Asa 100 mg/kg and Atu 100 mg/kg, while amoxicillin, Atu 400 mg/kg and Asa 400 mg/kg decreased PSSA counts in all-time points. No effect of any group against MRSA was observed at any time. Conclusion: Thus, A. sativum and A. tuberosum were able to reduce PSSA infection, but not MRSA infection.

The effect of two drug delivery systems in ropivacaine cytotoxicity and cytokine release by human keratinocytes and fibroblasts.

OBJECTIVES: Modified drug delivery systems have been developed to improve pharmacological properties of local anaesthetics. However, the inflammatory potential of these formulations was not investigated. This study compared the in-vitro effects of ropivacaine (ropi) in plain, liposomal (MLV) or 2-hydroxypropyl-ß-cyclodextrin (HP-ß-CD) formulations on cell viability, apoptosis and cytokine (IL-1α, TNF-α, IL-6 and IL-10) release. METHODS: Human immortalized keratinocytes (HaCaT) and human immortalized gingival fibroblasts (HGF) were exposed to 1-100 µm ropi concentrations. The cell viability was measured by XTT and LIVE/DEAD assay. Apoptosis was performed by flow cytometry, and cytokine release was measured by ELISA assay. KEY FINDINGS: Human immortalized keratinocyte viability was reduced by ropi and both drug delivery systems. However, none of the formulations induced apoptosis. Results showed a differential regulation of IL-1α TNF-α, IL-6 and IL-10 by HaCaT and HGF. Ropi-HP-ß-CD increased twofold the IL-6 release by HGF in comparison with the control, while 100 µm ropi-MLV led to an increased release of all pro-inflammatory cytokines by HGF. CONCLUSION: The loss in cell viability was not related to cellular apoptosis. Ropi complexed with HP-ß-CD showed a similar cytokine release pattern when compared to the plain formulation. Thus, the HP-ß-CD form was a better drug carrier than the MLV form for ropivacaine drug delivery.

Comparison of liposomal and 2-hydroxypropyl-ß-cyclodextrin-lidocaine on cell viability and inflammatory response in human keratinocytes and gingival fibroblasts.

OBJECTIVES: The aim of this study was to observe the effect multilamellar liposomes (MLV) and 2-hydroxypropyl-ß-cyclodextrin (HP-ß-CD) in the in-vitro effects of lidocaine in cell viability, pro-inflammatory cytokines and prostaglandin E2 release of both human keratinocytes (HaCaT) and gingival fibroblasts (HGF) cells. METHODS: HaCaT and HGF cells were exposed to lidocaine 100-1 µm in plain, MLV and HP-ß-CD formulations for 6 h or 24 h. The formulation effects in cell viability were measured by XTT assay and by fluorescent labelling. Cytokines (IL-8, IL-6 and TNF-α) and PGE2 release were quantified by ELISA. KEY FINDINGS: MLV and HP-ß-CD formulations did not affect the HaCaT viability, which was significantly decreased by plain lidocaine after 24 h of exposure. Both drug carriers increased all cytokines released by HGF after 24-h exposure, and none of the carriers was able to reduce the PGE2 release induced by lidocaine. CONCLUSION: The effect of drug carrier in the lidocaine effects was dependent on the cell type, concentration and time of exposure. MLV and HP-ß-CD showed benefits in improving cell viability; however, both of them showed a tendency to increase cytokine release when compared to the plain solution.

Neutrophilic infiltration in lungs of mice with peritonitis in acid or basic medium.

BACKGROUND: Bacterial peritonitis is associated with systemic complications such as pneumonia. OBJECTIVE: To determine in an experimental model of peritonitis whether the pH of peritoneal fluid infection influences the influx of neutrophils into the lung, and whether treatment outcome would be similar in peritonitis with liquid at any pH. MATERIALS AND METHODS: We studied 48 mice with peritonitis induced by cecal ligation and puncture. The animals were distributed randomly into three groups: the first one had an injection into the peritoneal cavity with saline, pH 7.0; the second group was injected with saline, pH 8.0; and the third group with saline, pH 3.0. After 2 hours, half the animals in each group was treated by washing the abdominal cavity with warm saline solution and administration of ceftriaxone every 12 hours, and half of each group was killed by anesthetic overdose, and lung biopsy was done. The animals kept in treatment were killed 24 hours after treatment, and lung biopsy was also performed. The samples were stained with H&E and the number of neutrophils in 20 areas was checked. The mean number of cells in each group was compared between groups and with an untreated one. RESULTS: The group with peritonitis associated with alkaline solution showed a higher population of neutrophils during untreated peritonitis (P = 0.04). The response to treatment by lavage of the peritoneal cavity and antibiotics was more effective in reducing the population of neutrophils in the group with peritonitis at pH 8.0, unlike that observed in animals with peritonitis at pH 3.0 (P = 0.03). CONCLUSION: Peritonitis associated with lower pH solution, despite the lower influx of leukocytes in the first two hours after installation of peritonitis, was not able to reduce the population of these cells in mice's lung in response to standard therapy.

Effect of 4-(N,N-dimethylamino)phenethyl Alcohol on Degree of Conversion and Cytotoxicity of Photo-Polymerized CQ-Based Resin Composites

The aim of this study was to evaluate the degree of conversion (DC) and the cytotoxicity of photo-cured experimental resin composites containing 4-(N,N-dimethylamino)phenethyl alcohol (DMPOH) combined to the camphorquinone (CQ) compared with ethylamine benzoate (EDAB). The resin composites were mechanically blended using 35 wt% of an organic matrix and 65 wt% of filler loading. To this matrix was added 0.2 wt% of CQ and 0.2 wt% of one of the reducing agents tested. 5x1 mm samples (n=5) were previously submitted to DC measurement and then pre-immersed in complete culture medium without 10% (v/v) bovine serum for 1 h or 24 h at 37 °C in a humidifier incubator with 5% CO2 and 95% humidity to evaluate the cytotoxic effects of experimental resin composites using the MTT assay on immortalized human keratinocytes cells. As a result of absence of normal distribution, the statistical analysis was performed using the nonparametric Kruskal-Wallis to evaluate the cytotoxicity and one-way analysis of variance to evaluate the DC. For multiple comparisons, cytotoxicity statistical analyses were submitted to Student-Newman-Keuls and DC analysis to Tukey's HSD post-hoc test (=0.05). No significant differences were found between the DC of DMPOH (49.9%) and EDAB (50.7%). 1 h outcomes showed no significant difference of the cell viability between EDAB (99.26%), DMPOH (94.85%) and the control group (100%). After 24 h no significant difference were found between EDAB (48.44%) and DMPOH (38.06%), but significant difference was found compared with the control group (p>0.05). DMPOH presented similar DC and cytotoxicity compared with EDAB when associated with CQ.

O objetivo deste estudo foi avaliar o grau de conversão (GC) e a citotoxicidade de resinas compostas experimentais utilizando o álcool 4-(N,N-dimetilamino) fenil etílico (DMPOH) associado à canforoquinona (CQ) como sistema fotoiniciador (SF) comparado à versão comercial utilizando o benzoato de etilamina (EDAB). Para tanto, as resinas compostas experimentais foram mecanicamente misturadas utilizando (em peso): 35% de matriz orgânica e 65% em peso de partículas de carga. Posteriormente, foram adicionados 0,2% de CQ e 0,2% de um dos agentes redutores testados. Amostras de 5 x 1 mm (n=5) foram previamentes submetidas à análise de GC e posteriormente, esterilizadas e colocadas no meio de cultura completo sem soro fetal bovino estéril por 1 h ou 24 h a 37 °C em encubadora com 5% de CO2 and 95% de umidade para avaliar os efeitos citotóxicos das resinas compostas experimentais utilizando o método MTT emcélulas células humanas imortalizadas de queratinócitos. Os dados de citotoxicidade foram submetidos à análise estatística de Kruskal-Wallis e de GC à análise de variância com um fator. Em virtude da ausência de normalidade, a análise estatística da citotoxicidade foi realizada utilizando-se o teste não-paramétrico de Kruskal-Wallis. Para o GC, os dados foram submetidos à análise de variaância de 1 fator. Posteriormente para múltiplas comparações, os dados de citotoxicidade foram submetidos ao teste Student-Newman-Keuls e o GC ao teste de Tukey's HSD post-hoc (=0.05). Não foi observada diferença estatística entre o GC de DMPOH (49,9%) e EDAB (50,7%). Para os resultados de 1 h não houve diferença na viabilidade celular entre EDAB (99,26%), DMPOH (94,85%) e o grupo controle (100%). Após 24 h, nenhuma diferença estatística foi encontrada entre EDAB (48,44%) e DMPOH (38,06%), entretanto, diferença significativa foi encontrada em relação ao grupo controle (p>0,05). O DMPOH apresentou GC e citotoxicidade semelhante à EDAB quando associado à CQ.

Tolerogenic microenvironment in neonatal period induced by maternal immunization with ovalbumin.

Maternal immunization with allergens, such as ovalbumin (OVA), can inhibit the development of an allergic response in offspring. The regulatory mechanisms seem to be mediated by maternal antibodies (MatAbs) and factors generated by the maternal-fetal interface. The aim of this study was to verify the pathways of inhibitory Ab transference after maternal immunization with OVA and the effect of the offspring's dendritic cells (DCs) on the generation of regulatory T (Treg) cells. We verified that preconceptional OVA immunization induces high levels of proinflammatory and regulatory cytokines in the amniotic fluid, allowing the transference of high levels of anti-OVA IgG1 Abs to the offspring. Using an adoptive nursing protocol, we verified that maternal immunization leads to MatAb transference by the placental route and by breastfeeding contribute to the inhibition of anaphylactic IgE and IgG1 Ab responses in immunized offspring. We observed that maternal immunization decreased eosinophil numbers in recovered bronchoalveolar lavage fluid and in the lung tissue, whereas with a lack of control of airway responsiveness to methacholine. Maternal immunization induced in young offspring a decreased percentage of CD11c+ DCs expressing MHC class II and CD40 molecules. Moreover, DCs from both groups of offspring when pulsed with OVA, were able to induce Treg cells in vitro. Similarly, OVA immunization at the neonatal stage increased the frequency of Treg cells, regardless of the mother's immunization status. These findings emphasize that maternal immunization leads to a complex interaction of regulatory factors, with MatAbs, DCs and Treg cells affecting the tolerance of offspring during an allergic response.

Effect of 4-(N,N-dimethylamino)phenethyl alcohol on degree of conversion and cytotoxicity of photo-polymerized CQ-based resin composites.

The aim of this study was to evaluate the degree of conversion (DC) and the cytotoxicity of photo-cured experimental resin composites containing 4-(N,N-dimethylamino)phenethyl alcohol (DMPOH) combined to the camphorquinone (CQ) compared with ethylamine benzoate (EDAB). The resin composites were mechanically blended using 35 wt% of an organic matrix and 65 wt% of filler loading. To this matrix was added 0.2 wt% of CQ and 0.2 wt% of one of the reducing agents tested. 5x1 mm samples (n=5) were previously submitted to DC measurement and then pre-immersed in complete culture medium without 10% (v/v) bovine serum for 1 h or 24 h at 37 °C in a humidifier incubator with 5% CO2 and 95% humidity to evaluate the cytotoxic effects of experimental resin composites using the MTT assay on immortalized human keratinocytes cells. As a result of absence of normal distribution, the statistical analysis was performed using the nonparametric Kruskal-Wallis to evaluate the cytotoxicity and one-way analysis of variance to evaluate the DC. For multiple comparisons, cytotoxicity statistical analyses were submitted to Student-Newman-Keuls and DC analysis to Tukey's HSD post-hoc test (=0.05). No significant differences were found between the DC of DMPOH (49.9%) and EDAB (50.7%). 1 h outcomes showed no significant difference of the cell viability between EDAB (99.26%), DMPOH (94.85%) and the control group (100%). After 24 h no significant difference were found between EDAB (48.44%) and DMPOH (38.06%), but significant difference was found compared with the control group (p>0.05). DMPOH presented similar DC and cytotoxicity compared with EDAB when associated with CQ.

Maternal immunization with ovalbumin prevents neonatal allergy development and up-regulates inhibitory receptor Fc gamma RIIB expression on B cells.

BACKGROUND: Preconception allergen immunization prevents neonatal allergen sensitization in mice by a complex interaction between regulatory cells/factors and antibodies. The present study assessed the influence of maternal immunization with ovalbumin (OVA) on the immune response of 3 day-old and 3 week-old offspring immunized or non-immunized with OVA and evaluated the effect of IgG treatment during fetal development or neonatal period. RESULTS: Maternal immunization with OVA showed increased levels of Fc gamma RIIb expression in splenic B cells of neonates, which were maintained for up to 3 weeks and not affected by additional postnatal OVA immunization. Maternal immunization also exerted a down-modulatory effect on both IL-4 and IFN-gamma-secreting T cells and IL-4 and IL-12- secreting B cells. Furthermore, immunized neonates from immunized mothers showed a marked inhibition of antigen-specific IgE Ab production and lowered Th2/Th1 cytokine levels, whereas displaying enhanced Fc gamma RIIb expression on B cells. These offspring also showed reduced antigen-specific proliferative response and lowered B cell responsiveness. Moreover, in vitro evaluation revealed an impairment of B cell activation upon engagement of B cell antigen receptor by IgG from OVA-immunized mice. Finally, in vivo IgG transference during pregnancy or breastfeeding revealed that maternal Ab transference was able to increase regulatory cytokines, such as IL-10, in the prenatal stage; yet only the postnatal treatment prevented neonatal sensitization. None of the IgG treatments induced immunological changes in the offspring, as it was observed for those from OVA-immunized mothers. CONCLUSION: Maternal immunization upregulates the inhibitory Fc gamma RIIb expression on offspring B cells, avoiding skewed Th2 response and development of allergy. These findings contribute to the advancement of prophylactic strategies to prevent allergic diseases in early life.