L-lysine: Its antagonism with L-arginine in controlling viral infection. Narrative literature review.

Knowledge about viral characteristics, mechanisms of entry into the host cell and multiplication/dissemination can help in the control and treatment of viral pathologies. Several nutritional factors linked to the host may favour viral multiplication and their control, may lead to new prophylactic alternatives and/or antiviral therapies. The objective of this review is to discuss the relationship between the amino acid L-lysine and the control of viral infections, aiming at a possible therapeutic property. This research used databases such as PubMed, Web of Science, Scielo, Medline and Google Scholar, as well as searching for references cited by journals. The time frame covered the period between 1964 and January 2022. The observed studies have shown that the usual antiviral therapies are not able to interfere with the viruses in their latent state; however, they can interfere with the adhesion and fusion of viral particles or the production of proteins, which play an important role in viral epidemiology and control, particularly in the initial moment and in reactivation. Lysine is an amino acid that can interfere mainly in the formation of capsid proteins and DNA by a competitive antagonism with amino acid arginine, which is an essential amino acid for some viruses, and also by promoting the increase of arginase, increasing the catabolism of arginine. Although there is evidence of the importance of L-lysine in viral control, more studies are needed, with a view to new antiviral therapies.

The impact of digital filters on the diagnosis of simulated root resorptions in digital radiographic systems.

OBJECTIVES: To evaluate the influence of digital filters of intraoral radiographic systems on the diagnosis of simulated internal and external root resorptions and image quality. MATERIALS AND METHODS: Internal root resorption (IRR) and external root resorption (ERR) were simulated in 34 teeth. For image acquisition, two radiographic systems were used: Digora Toto and VistaScan. All filters available in these systems were applied. Three observers scored the detection of root resorptions in a 5-point scale. The noise and the contrast-to-noise ratio (CNR) were calculated. The area under ROC curve, sensitivity, specificity, and accuracy were obtained. One-way ANOVA with Tukey's post hoc tests compared the diagnostic values, noise, and CNR between the filters (α = 0.05). RESULTS: For ERR, there were no significant differences in diagnostic values between the filters tested for both systems. For IRR, Original and Noise Reduction filters presented higher sensitivity than the Sharpen2 filter for images from Digora Toto, with no differences between the other groups. For VistaScan, there were no significant differences of diagnostic values between the groups studied. Noise values differed among the filters of both systems. The CNR of the filters differed only for the bone region for Digora Toto, while for VistaScan, both tooth and bone regions differed. CONCLUSIONS: Despite promoting changes in pixel intensities and affecting the noise level of the radiographic images, the digital filters of Digora Toto and VistaScan systems do not affect the diagnosis of internal or external root resorptions. CLINICAL RELEVANCE: Digital filters are common tools in digital radiographic systems and may be used by the professional without impairment in root resorptions diagnosis.

L-lysine therapy to control the clinical evolution of pityriasis rosea: Clinical case report and literature review.

Pityriasis rosea (PR) is a dermatological disease with an erythemato-papulosquamous manifestation, distributed on the trunk and extremities affecting healthy people, especially children and young people between 10 and 35 years of age. The evolution is 6 to 8 weeks and may remain for 3 to 6 months. It regresses spontaneously and can leave changes in the skin color but reversibly. Acyclovir is indicated to minimize clinical manifestations with the suspected of viral association (HHV-6 and 7). Another group of the human herpesvirus family (HHV-1 and 2), causes herpes simplex that is controlled with the antivirals, including acyclovir, as well as the amino acid L-lysine, both showing positive and similar results in reducing the number of annual manifestations and the healing time of the lesions. The aim of this study is to report a case of PR in a child, to review the literature on the etiopathogenesis of the disease and on the effects of L-lysine as well as another amino acid in the treatment. An 11-year-old girl, phototype II, presented lesions diagnosed as PR. The cycle would be 6 to 8 weeks on average. A solution of L-lysine was prescribed for 30 days, on an empty stomach. After the fourth day of therapy, the cycle of new eruptions was interrupted, initial lesions regressed, accelerating the repair of larger lesions resulting in an improvement of the clinical condition. We concluded that the administration of L-lysine, in therapeutic doses, can be a safe alternative for the PR control.

Buffered 2% articaine versus non-buffered 4% articaine in maxillary infiltration: randomized clinical trial.

OBJECTIVES: This randomized, triple-blind, crossover clinical trial aimed to evaluate the efficacy, onset, length of pulp and soft tissue anesthesia, and pain during injection of 2% buffered articaine and 4% non-buffered articaine solutions. METHODS: Each volunteer received two maxillary supraperiosteal anesthesia infiltrations in canine area. The infiltrations were performed at two different sessions using a different local anesthetic solution for each session, and the anesthetic injection speed was always 1 mL/min. The assessment of the onset and length of pulpal and soft tissue anesthesia was performed with the pulp electrical test "pulp tester" and the esthesiometer kit, respectively. Volunteers marked pain during injection on a visual analog scale (VAS). The anesthetics solutions pH was evaluated through the pH meter equipment. RESULTS: There was no difference between the two anesthetic solutions (onset of soft tissue anesthesia, p = 0.5386; length of soft tissue anesthesia, p = 0.718; onset of pulpal anesthesia, p = 0.747; length of pulpal anesthesia, p = 0.375), except for pain during the injection which was lower when buffered 2% articaine was used (p = 0.001) and the pH. The pH analysis revealed that the solutions differed from one another (p < 0.01). CONCLUSION: The 2% buffered articaine solution provided the same anesthetic properties then 4% unbuffered articaine with a great reduction in pain during injection. CLINICAL RELEVANCE: The possibility of use 2% buffered articaine solution instead of 4% articaine maintaining the same anesthetic properties with a great reduction in pain during injection and half of the anesthetic salt concentration.

Herbal medicines as anxiolytics prior to third molar surgical extraction. A randomized controlled clinical trial.

OBJECTIVES: This study aimed to compare the effects of Passiflora incarnata, Erythrina mulungu, and midazolam in controlling anxiety in patients undergoing mandibular third molar extraction. METHODS: The volunteers underwent extraction of their third mandibular molars in a randomized, placebo-controlled, triple-blind, and parallel clinical trial. Passiflora incarnata (500 mg), Erythrina mulungu (500 mg), or midazolam (15 mg) was orally administered 60 min before the surgery. The anxiety level of participants was evaluated using questionnaires and measurements of physical parameters, including heart rate (HR), blood pressure (BP), and oxygen saturation (SpO2). RESULTS: A total of 200 volunteers were included in this clinical trial. Considering each procedure independently, no significant differences (p > 0.05) in BP, HR, and SpO2 were observed among the protocols. CONCLUSIONS: Passiflora incarnata showed a similar effect to midazolam but differed from placebo and mulungu, which were unable to control anxiety in this situation. Therefore, the results suggest that Passiflora configures an herbal medicine with an anxiolytic effect, adequate to use in third molar extractions. CLINICAL RELEVANCE: The use of Passiflora incarnata may be an alternative to benzodiazepines for controlling anxiety in patients scheduled for oral surgery under local anesthesia. TRIAL REGISTRATION: ClinicalTrials.gov : ANSI-388.427.

Variations in pulp volume between normotensive and hypertensive individuals on CBCT imaging.

OBJECTIVES: To compare the pulp volume of individuals with altered and normal systemic blood pressure (BP) in order to verify if high BP promotes dimensional modifications in the pulp space. MATERIALS AND METHODS: Cone beam computed tomography scans of 91 patients (49 females and 42 males, mean age 31.7 ± 6.38 years) who had a healthy maxillary canine were selected. Values of arterial BP measured at two dental visits were used to classify the sample as normal BP (< 130 × 80 mmHg) and altered BP (≥ 130 × 80 mmHg); 49 patients had normal BP and 42 had altered BP. One oral radiologist evaluated each patient's pulp and tooth volumes, using semi-automatic segmentation, and the tooth length. Data were submitted to Student's t test and logistic regression, with a significance level of 5% (p < 0.05). RESULTS: Pulp volume (p = 0.0027), pulp volume/tooth volume (p = 0.0013), and pulp volume/tooth length (p = 0.0007) ratios were greater in the altered BP group. Conversely, there was no difference in tooth volume between the groups (p = 0.0697). A logistic regression model (p = 0.0002) using pulp volume and age enabled the development of a formula for predicting altered BP, with 68% accuracy. CONCLUSIONS: Individuals with altered systemic BP have greater pulp volumes than those with normal BP. The formula developed in this study may indicate the presence of altered BP. CLINICAL RELEVANCE: As arterial hypertension is a silent disease that produces no warning signs or symptoms, identification of modifications in the pulp volume in cone beam computed tomography scans may be an adjuvant sign of the diagnosis of this disease.

Comparison of two vasoconstrictors on glycemic levels in diabetic patients.

OBJECTIVES: The aim of this study was to evaluate glycemic levels in diabetic patients before, during, and after extractions using 2% lidocaine with 1:100,000 epinephrine (Lido/Epi) and 3% prilocaine with 0.03 IU/mL felypressin (Prilo/Fely). MATERIALS AND METHODS: A double-blind, randomized clinical trial was conducted to evaluate changes in body parameters and glycemic levels in diabetic patients undergoing two anesthetic protocols during dental extractions. During surgery, we evaluated blood pressure (BP), heart rate (HR), saturation (SpO2), and capillary glycemic levels (Gly). These parameters were measured at the following surgical moments: basal, 30 min after medication, incision, tooth removal, suture, and 30 and 60 min after anesthesia. RESULTS: Data analysis showed no differences between the groups considering age, weight, and time spent in surgery. Increased systolic BP and decreased diastolic BP were observed in the lido/epi group. No difference was observed in the prilo/fely group among the surgical moments or between the groups regarding BP. No difference was observed in HR and SpO2 between the groups at any surgical moment. However, differences were found when compared the differences in glycemic and basal levels in both groups with greater decreases in blood glucose values for the lido/epi group. In anxiety level evaluation, there was no difference between the different surgical moments. CONCLUSION: Thus, both lido/epi and prilo/fely (maximum 3.6 mL) can be safely used in controlled diabetic patients CLINICAL RELEVANCE: The use of lidocaine associated with epinephrine did not increase glycemic levels but leads to decrease over time when associated with an anxiety reduction protocol, offering some advantage over prilocaine plus felypressin for diabetic patients.

Systemic and periodontal conditions of overweight/obese patients during pregnancy and after delivery: a prospective cohort.

OBJECTIVE: To evaluate the systemic and periodontal conditions, as well as the determinants of health in pregnant women with and without obesity/overweight during the second and third trimesters of pregnancy and after delivery. MATERIALS AND METHODS: In the second trimester (T1), 93 pregnant women were divided into two groups with either excessive weight (G1, n = 53) or normal weight (G2, n = 40) and subsequently examined them in the third trimester of pregnancy (T2) and at least 2 months after delivery (T3). The following variables were analyzed: (a) systemic impairments during pregnancy-arterial hypertension (AH) and gestational diabetes mellitus (GDM); (b) oral hygiene behavior; (c) periodontal conditions; (d) anthropometric data and systemic health condition after pregnancy. The Mann-Whitney test, chi-squared test, ANOVA, and binary logistic regression were adopted (p < 0.05). RESULTS: G1 showed higher frequency of GDM and AH in T1 and T2, respectively (p = 0.047; p = 0.004). Both groups had worse oral hygiene behaviors after delivery. A higher frequency of periodontitis was found in all periods for G1 (p < 0.05). G2 showed improvement of all periodontal parameters after delivery, whereas G1 showed no difference regarding these parameters between time periods. CONCLUSION: Pregnant women with excessive weight presented worse systemic and periodontal conditions during pregnancy and after delivery. CLINICAL RELEVANCE: Low socioeconomic level and overweight/obesity were significant predictors of periodontitis during pregnancy and after delivery.

Development and validation of a formula based on maxillary sinus measurements as a tool for sex estimation: a cone beam computed tomography study.

BACKGROUND: As sex estimation is an important step to delineate the biological profile, the development of tools employing anatomical structures which may maintain their integrity even after extreme events, such as the maxillary sinus, become useful for forensic identification. Thus, the aim in the present study was to develop and validate a formula for sex estimation through measurements in the maxillary sinuses in a Brazilian population, using cone beam computed tomography (CBCT) scans. MATERIAL AND METHODS: Linear and volumetric measurements in the maxillary sinus were performed bilaterally in 94 CBCT scans from 45 males (mean age 25.2 ± 0.79) and 49 females (mean age 23.7 ± 0.50). The OnDemand 3D software was employed for linear measurements (height, length and width of, and the largest distance between the right and left maxillary sinuses), while the ITK-SNAP 3.0 segmentation software was used to acquire the volume. The data obtained was applied to a mathematical model for sex estimation. To validate the developed formula, another sample composed of 60 CBCT images of Brazilian individuals was tested. RESULTS: Overall, maxillary sinuses' measurements were significantly higher in males, without statistically significant differences between the right and left sides within each group. The most dimorphic measurement was the height, with an accuracy of 77.7% regarding sex estimation. The formula created lead to a sex estimation of 87.8% for females and 80% for males, with an overall accuracy of 84%. When the formula validity was tested in another sample, it showed an accuracy of 82.4%. CONCLUSION: The formula developed through measurements in the maxillary sinus using CBCT scans showed an accuracy of 84% for sex estimation and can be applied as a complementary method for human identification in the Brazilian population.

Stress-related salivary proteins affect the production of volatile sulfur compounds by oral bacteria.

OBJECTIVE: To determine whether stress-related substances and sex hormones influence the growth and in vitro production of volatile sulfur compounds (VSCs) by Solobacterium moorei and Fusobacterium nucleatum. MATERIALS AND METHODS: Bacteria growth and VSCs production were evaluated in the presence of alpha-amylase, beta-defensin-2, mucin, estradiol, and progesterone. Growth was evaluated by colony counting, and the production of the VSCs hydrogen sulfide (H2 S) and methyl mercaptan (CH3 SH) was measured using the Oral Chroma™ instrument. RESULTS: Mucin induced the production of H2 S by both bacteria, but had a slight inhibitory effect on CH3 SH production by F. nucleatum. It also increased the viability of F. nucleatum. Alpha-amylase increased H2 S production by S. moorei and CH3 SH production by F. nucleatum, but had no effect on H2 S production by F. nucleatum. No substance altered the viability of S. moorei. No effects of beta-defensin-2, estradiol, or progesterone were observed. CONCLUSION: The salivary stress-related proteins mucin and alpha-amylase altered VSCs production by F. nucleatum and S. moorei, favoring H2 S production. These findings are a step toward understanding the relation between stress and increased amounts of H2 S.

Evaluation of metal artefact reduction in cone-beam computed tomography images of different dental materials.

OBJECTIVE: The aim of this study is to evaluate the efficacy of metal artefact reduction (MAR) in different dental materials with Picasso Trio cone-beam computed tomography (CBCT) scanner. MATERIALS AND METHODS: Three imaging phantoms were custom-made of acrylic resin. Each phantom presented three cylinders of the same material: dental amalgam alloy, gutta-percha or aluminium-copper alloy. CBCT scans were performed on Picasso Trio unit with and without MAR, and artefact expression (standard deviation of grey values) was obtained and compared by Kruskal-Wallis and Student-Newman-Keuls (post hoc) (α = 0.05). RESULTS: Significant reduction of artefact expression (p < 0.05) was observed with MAR on areas around dental alloys. No significant difference (p > 0.05) was observed with or without MAR when gutta-percha was scanned. CONCLUSION: MAR was effective in reducing artefacts arising from dental alloys on CBCT images. CLINICAL RELEVANCE: Dental materials of high atomic number and density are widely used in dentistry and can produce artefact that compromise CBCT image. The present study demonstrated that metal artefact reduction algorithm is an effective tool to improve image quality.

Evaluation of pharyngeal space and its correlation with mandible and hyoid bone in patients with different skeletal classes and facial types.

INTRODUCTION: The purpose of this article was to evaluate the pharyngeal space volume, and the size and shape of the mandible and the hyoid bone, as well as their relationships, in patients with different facial types and skeletal classes. Furthermore, we estimated the volume of the pharyngeal space with a formula using only linear measurements. METHODS: A total of 161 i-CAT Next Generation (Imaging Sciences International, Hatfield, Pa) cone-beam computed tomography images (80 men, 81 women; ages, 21-58 years; mean age, 27 years) were retrospectively studied. Skeletal class and facial type were determined for each patient from multiplanar reconstructions using the NemoCeph software (Nemotec, Madrid, Spain). Linear and angular measurements were performed using 3D imaging software (version 3.4.3; Carestream Health, Rochester, NY), and volumetric analysis of the pharyngeal space was carried out with ITK-SNAP (version 2.4.0; Cognitica, Philadelphia, Pa) segmentation software. For the statistics, analysis of variance and the Tukey test with a significance level of 0.05, Pearson correlation, and linear regression were used. RESULTS: The pharyngeal space volume, when correlated with mandible and hyoid bone linear and angular measurements, showed significant correlations with skeletal class or facial type. The linear regression performed to estimate the volume of the pharyngeal space showed an R of 0.92 and an adjusted R2 of 0.8362. CONCLUSIONS: There were significant correlations between pharyngeal space volume, and the mandible and hyoid bone measurements, suggesting that the stomatognathic system should be evaluated in an integral and nonindividualized way. Furthermore, it was possible to develop a linear regression model, resulting in a useful formula for estimating the volume of the pharyngeal space.

Assessing pulp stones by cone-beam computed tomography.

OBJECTIVES: The aim of this study was to evaluate the occurrence of pulp stones by cone-beam computed tomography (CBCT) and to correlate their prevalence with patient's gender, location of tooth (right or left of maxillary or mandibular arch), group of teeth, and restorations. MATERIALS AND METHODS: CBCT images of 382 patients randomly selected from the database of the University Oral Radiology Department were retrospectively examined. A total of 2833 tooth images obtained using the i-CAT 3D Imaging System were evaluated. Image analysis was performed with the i-CAT software, and all teeth were evaluated in sagittal, axial, and coronal views. All the measurements were subjected to chi square test, odds ratio, and Fisher's exact tests (p < 0.05). RESULTS: The prevalence of pulp stones was similar between patient's genders and tooth locations. Pulp stones were detected in 31.9% of patients and 9.5% of teeth. Maxillary and mandibular molars were the groups of teeth with the highest frequency of pulp stones. The presence of restorations increased the chance of occurrence of pulp stones by 2.1 times in all teeth examined (p < 0.0001) and by 4.7 times in maxillary teeth (p < 0.0001). CONCLUSIONS: Pulp stones had a high prevalence with molar teeth showing the highest prevalence. The presence of restorations increased the chance of occurrence of these calcifications, specifically in maxillary teeth. CLINICAL RELEVANCE: CBCT provides accurate anatomical details in three dimensions, offering the possibility to view an individual tooth in axial, sagittal, and coronal views. This study performed an investigation of the occurrence of pulp stones by CBCT.

Comparison of Articaine and Lidocaine for Buccal Infiltration After Inferior Alveolar Nerve Block For Intraoperative Pain Control During Impacted Mandibular Third Molar Surgery.

In order to compare the efficacy of lidocaine and articaine for pain control during third molar surgery, 160 patients presenting bilateral asymptomatic impacted mandibular third molars were selected. They received 1.8 mL of 2% lidocaine with epinephrine 1:100,000 during inferior alveolar nerve block. In group 1 (n = 80), an infiltrative injection of 0.9 mL of 2% lidocaine with epinephrine 1:100,000 was performed in buccal-distal mucosa of the third molar. Group 2 (n = 80) received 0.9 mL of 4% articaine with epinephrine 1:100,000 in the contralateral side. All procedures were performed at the same visit, by a single operator, in a double-blind and parallel design. The duration of each surgery and the moment when the patient expressed pain were noted. Data were analyzed by nonpaired t test and chi-square test (alpha = 5%). Duration of surgery did not differ (p = .83) between Groups 1 (19.8 ± 2.3 minutes) and 2 (19.7 ± 3.0 minutes). Pain was expressed more in group 1 (26.3%) than in group 2 (10%) (odds ratio = 3.2, p = .0138). In both groups, tooth sectioning was the most painful event (p < .0001). No influence of gender (p = .85) or age (p = .96) was observed in pain response. Buccal infiltration of 4% articaine with epinephrine 1:100,000 showed more efficacy than 2% lidocaine with epinephrine 1:100,000 when used in combination with inferior alveolar nerve block in controlling intraoperative pain related to impacted mandibular third molar surgery.

The influence of number of line pairs in digital intra-oral radiography on the detection accuracy of horizontal root fractures.

AIM: Line pairs are the unit for measurement of resolution and are related to the spatial quality of the system. Thus, the objective of this study was to evaluate the influence of number of line pairs in digital intra-oral radiography on the detection accuracy of horizontal root fractures. MATERIALS AND METHODS: Sixty-four extracted single-root human teeth were used. Thirty-two had horizontal root fractures created and were mounted in dry human mandibles. The teeth were radiographed with two digital receptors: the Digora Optime (14.3 lp mm-1) and the Digora Toto (26.3 lp mm-1). Images were viewed under standardized conditions by 3 calibrated examiners using the respective dedicated software (Digora for Windows 2.6(®) and Scanora(®) ). Digora Toto(®) images were also evaluated through the Digora for Windows 2.6(®) software. The results were statistically analyzed based on the area under the ROC curve for each examiner. RESULTS: Pairing Digora Toto(®) with Scanora(®) allowed for greater accuracy in horizontal root fractures diagnosis, while images acquired with that same system seem to lose accuracy when visualized with Digora for Windows 2.6(®) . Pairing Digora Optime(®) with Digora for Windows 2.6(®) resulted in the lowest accuracy for horizontal root fractures diagnosis. CONCLUSIONS: The higher number of line pairs and the consequent higher image resolution provided by the Digora Toto(®) system and its dedicated software seem to enhance the accuracy of horizontal root fractures diagnostic imaging.

Relationship of craniofacial morphology in 3-dimensional analysis of the pharynx.

INTRODUCTION: Pharynx dimensions may vary according to the position and morphology of the mandible. The aim of this study was to test the hypothesis that craniofacial morphology affects pharyngeal volume and its cross-sectional areas. METHODS: Seventy-four subjects (38 men, 36 women) aged 18 to 56 years (mean ± SD 32.8 ± 1.8 years) were scanned with a cone-beam computed tomography unit and had facial profile photographs taken. All participants were classified according to skeletal anteroposterior (Class II and Class III) and vertical facial patterns (brachyfacial, mesofacial, and dolichofacial). Facial profile analyses and pharyngeal volume and cross-sectional area determinations were performed. RESULTS: The soft palate cross-sectional area of the oropharynx was significantly greater in the Class III patients. The upper facial third (trichion to soft tissue glabella/facial height) correlated negatively with pharyngeal volume and with soft palate cross-sectional area in the oropharynx. Alternatively, the midfacial third (soft tissue glabella to subnasale/facial height) correlated positively with soft palate cross-sectional area of the oropharynx. No significant differences across sexes and facial patterns regarding pharyngeal volume were found (P >0.05). CONCLUSIONS: The soft palate cross-sectional area is larger in skeletal Class III subjects. It seems that analysis of the facial profile focusing on the proportions of the facial thirds allows for inferences on pharyngeal dimensions. However, anteroposterior skeletal facial type and vertical facial pattern do not seem to affect pharyngeal volume.

Mesial inclination of impacted third molars and its propensity to stimulate external root resorption in second molars--a cone-beam computed tomographic evaluation.

PURPOSE: To investigate the presence of external root resorption (ERR) in second molars adjacent to horizontally and mesioangular impacted mandibular third molars by cone-beam computed tomography. In addition, patient characteristics (age and gender) and third molar depth were correlated with the presence of ERR. MATERIALS AND METHODS: The sample consisted of 116 scans (58 acquired on the i-CAT Classic and 58 on the Picasso-Trio) of 70 women and 46 men (mean age, 23.7 yr). Two observers recorded the presence of ERR in the second molars, inclination and depth of third molars in relation to bone and soft tissues, third molars classification according to Pell and Gregory, and location and severity of ERR. Data were analyzed by analysis of variance, Mann-Whitney test, and χ(2) test. The κ test was used to analyze intraobserver agreement. RESULTS: The overall prevalence of ERR was 49.43%. There were no statistically significant differences in the detection of ERR by gender, images from the 2 devices, or third molar inclination (P > .05). The κ test showed excellent reproducibility values (κ = 0.7778). There was a smaller proportion of affected patients 14 to 24 years old and ERR in teeth adjacent to Class C third molars. CONCLUSION: Mesially inclined third molars (mesioangular and horizontal) have a greater potential of being associated with ERR in second molars, which was shown by the high prevalence of the condition in the overall sample. Class A and B third molars in patients older than 24 years were more associated with the presence of ERR in adjacent teeth.

Liposomal lidocaine gel for topical use at the oral mucosa: characterization, in vitro assays and in vivo anesthetic efficacy in humans.

OBJECTIVE: To characterize liposomal-lidocaine formulations for topical use on oral mucosa and to compare their in vitro permeation and in vivo anesthetic efficacy with commercially available lidocaine formulations. MATERIALS AND METHODS: Large unilamellar liposomes (400 nm) containing lidocaine were prepared using phosphatidylcholine, cholesterol, and α-tocoferol (4:3:0.07, w:w:w) and were characterized in terms of membrane/water partition coefficient, encapsulation efficiency, size, polydispersity, zeta potential, and in vitro release. In vitro permeation across pig palatal mucosa and in vivo topical anesthetic efficacy on the palatal mucosa in healthy volunteers (double-blinded cross-over, placebo controlled study) were performed. The following formulations were tested: liposome-encapsulated 5% lidocaine (Liposome-Lido5); liposome-encapsulated 2.5% lidocaine (Liposome-Lido2.5); 5% lidocaine ointment (Xylocaina®), and eutectic mixture of lidocaine and prilocaine 2.5% (EMLA®). RESULTS: The Liposome-Lido5 and EMLA showed the best in vitro permeation parameters (flux and permeability coefficient) in comparison with Xylocaina and placebo groups, as well as the best in vivo topical anesthetic efficacy. CONCLUSION: We successfully developed and characterized a liposome encapsulated 5% lidocaine gel. It could be considered an option to other topical anesthetic agents for oral mucosa.

A puzzle used to teach the cardiac cycle.

The aim of the present article is to describe a puzzle developed for use in teaching cardiac physiology classes. The puzzle presents figures of phases of the cardiac cycle and a table with five columns: phases of cardiac cycle, atrial state, ventricular state, state of atrioventricular valves, and pulmonary and aortic valves. Chips are provided for use to complete the table. Students are requested to discuss which is the correct sequence of figures indicating the phases of cardiac cycle. Afterward, they should complete the table with the chips. Students of biology, dentistry, medicine, pharmacy, and nursing graduation courses from seven institutions performed the puzzle evaluation. They were invited to indicate whether the puzzle had been useful for learning about the subject by filling one of four alternatives. Of the students, 4.6% answered that it was not necessary but helped them to confirm what they had learned, 64.5% reported that although they had previously understood the cardiac cycle, the puzzle helped them to solve doubts and promoted a better understanding of it, and 30.9% said that they needed the puzzle to understand the cardiac cycle, without differences among courses, institutions, and course semesters. The results of the present study suggest that a simple and inexpensive puzzle may be useful as an active learning methodology applied after the theoretical lecture, as a complementary tool for studying cardiac cycle physiology.