Effects of low level laser therapy (808 nm) on physical strength training in humans

Recent studies have investigated whether low level laser therapy (LLLT) can optimize human muscle performance in physical exercise. This study tested the effect of LLLT on muscle performance in physical strength training in humans compared with strength training only. The study involved 36 men (20.8 +/- 2.2 years old), clinically healthy, with a beginner and/or moderate physical activity training pattern. The subjects were randomly distributed into three groups: TLG (training with LLLT), TG (training only) and CG (control). The training for TG and TLG subjects involved the leg-press exercise with a load equal to 80% of one repetition maximum (1RM) in the leg-press test over 12 consecutive weeks. The LLLT was applied to the quadriceps muscle of both lower limbs of the TLG subjects immediately after the end of each training session. Using an infrared laser device (808 nm) with six diodes of 60 mW each a total energy of 50.4 J of LLLT was administered over 140 s. Muscle strength was assessed using the 1RM leg-press test and the isokinetic dynamometer test. The muscle volume of the thigh of the dominant limb was assessed by thigh perimetry. The TLG subjects showed an increase of 55% in the 1RM leg-press test, which was significantly higher than the increases in the TG subjects (26%, P = 0.033) and in the CG subjects (0.27%, P < 0.001). The TLG was the only group to show an increase in muscle performance in the isokinetic dynamometry test compared with baseline. The increases in thigh perimeter in the TLG subjects and TG subjects were not significantly different (4.52% and 2.75%, respectively; P = 0.775). Strength training associated with LLLT can increase muscle performance compared with strength training only.

Relationship between changes in insulin sensitivity and associated cardiovascular disease risk factors in thiazolidinedione-treated, insulin-resistant, nondiabetic individuals: pioglitazone versus rosiglitazone

This study compared the effects of administering rosiglitazone (RSG) vs pioglitazone (PIO) oil cardiovascular disease risk factors in insulin-resistant. nondiabetic individuals with no apparent disease. Twenty-two nondiabetic, apparently healthy individuals, classified as being insulin resistant oil the basis of a steady-state plasma glucose concentration of at least 10 mmol/L during the insulin suppression test, were treated with either RSG or 1110 for 3 months. Measurements were made before and after drug treatment of weight; blood pressure; fasting and daylong glucose, insulin, and free fatty acid (FFA) levels; and lipid and lipoprotein concentrations. Insulin sensitivity (steady-state plasma glucose concentration) significantly improved in both treatment groups, associated with significant decreases in daylong plasma concentrations of glucose, insulin, and FFA. Diastolic blood pressure fell somewhat in both groups, and this change reached significance in those receiving PIO. Improvement in lipid metabolism was confined to the PIO-treated group, signified by a significant decrease in plasma triglyceride concentration, whereas triglyceride concentration did not decline in the RSG-treated group, and these individuals also had increases in total (P = .047) and low-density lipoprotein cholesterol (P = .07). In conclusion, RSG and PIO appear to have comparable abilities to improve insulin sensitivity and lower daylong glucose, insulin, and FFA concentrations in nondiabetic, insulin-resistant individuals. However, despite these similarities, their effects on lipoprotein metabolism seem to be quite different, with beneficial effects confined to PIO-treated individuals. (C) 2009 Elsevier Inc. All rights reserved.

Enantioselectivity in the Pharmacokinetic Interaction Between Fluvastatin and Lercanidipine in Healthy Volunteers

Hypertension and dyslipidemia are independent risk factors for cardiovascular mortality and are frequently present in the same patient. Fluvastatin (FV), used to reduce cholesterol levels, and lercanidipine (LER), used to control blood pressured are marketed as racemic mixtures. Therapeutic activities are 30-fold higher for (+)-3R,5S-FV and 100- to 200-fold higher for S-LER compared with their respective antipodes. The present study describes the enantioselective pharmacokinetic interaction between LER and FV in healthy volunteers. A crossover randomized study was conducted in 3 phases on 8 volunteers treated with a single oral racemic dose of LER (20 mg) or FV (40 mg) or LER plus FV. Serial blood samples were collected from 0 to 24 hours. Plasma concentrations of the LER and FV enantiomers were determined by liquid chromatography/tandem mass spectrometry, and pharmacokinetic parameters were evaluated using the WinNonlin software. The Wilcoxon and Mann-Whitney tests (P < .05) were used to analyze enantiomer ratios and the pharmacokinetic drug interaction. Data are expressed as medians. In monotherapy, the kinetic disposition of both FV and LER was enantioselective. AUC values were significantly higher for (-)-3S,5R-FV than for (+)-3R,5S-FV (358.20 vs 279.68 ng.h/mL) and for S-LER compared with R-LER (13.90 vs 11.88 ng.h/mL). The pharmacokinetic parameters of FV were not enantioselective when combined with LER (AUC: (-)-3S,5R-FV: 325.21; (+)-3R,5S-FV: 316.44 ng.h/mL). There was a significant reduction in S-LER (8.06 vs 13.90 ng.h/mL) and R-LER (6.76 vs 11.88 ng.h/mL) AUC values when FV was coadministered. In conclusion, the interaction between FV-LER might be clinically relevant because AUC values of (+)-3R,5S-FV were increased when LER was coadministered, and AUC values of the 2 LER enantiomers were reduced when FV was coadministered.

Albendazole-praziquantel interaction in healthy volunteers: kinetic disposition, metabolism and enantioselectivity

center dot Pharmacokinetic interactions between albendazole and praziquantel are based on plasma concentrations of the enantiomeric mixture of both drugs with contradictory data, although the antiparasitic activity arises from (-)-(R)-praziquantel and (+)-albendazole sulfoxide. WHAT THIS STUDY ADDS center dot The pharmacokinetic interaction between albendazole and praziquantel is enantioselective. Praziquantel increased the plasma concentrations of (+)-albendazole sulfoxide more than those of (-)-albendazole sulfoxide and the administration of albendazole did not change the kinetic disposition of (+)-(S)-praziquantel, but increased the plasma concentration of (-)-(R)-praziquantel. AIM This study investigated the kinetic disposition, metabolism and enantioselectivity of albendazole (ABZ) and praziquantel (PZQ) administered alone and in combination to healthy volunteers. METHODS A randomized crossover study was carried out in three phases (n = 9), in which some volunteers started in phase 1 (400 mg ABZ), others in phase 2 (1500 mg PZQ), and the remaining volunteers in phase 3 (400 mg ABZ + 1500 mg PZQ). Serial blood samples were collected from 0-48 h after drug administration. Pharmacokinetic parameters were calculated using a monocompartmental model with lag time and were analyzed using the Wilcoxon test; P < 0.05. RESULTS The administration of PZQ increased the plasma concentrations of (+)-ASOX (albendazole sulphoxide) by 264% (AUC 0.99 vs. 2.59 mu g ml-1 h), (-)-ASOX by 358% (0.14 vs. 0.50 mu g ml-1 h) and albendazole sulfone (ASON) by 187% (0.17 vs. 0.32 mu g ml-1 h). The administration of ABZ did not change the kinetic disposition of (+)-(S)-PZQ (-)-(R)-4-OHPZQ or (+)-(S)-4-OHPZQ, but increased the plasma concentration of (-)-(R)-PZQ by 64.77% (AUC 0.52 vs. 0.86 mu g ml-1 h). CONCLUSIONS The pharmacokinetic interaction between ABZ and PZQ in healthy volunteers was demonstrated by the observation of increased plasma concentrations of ASON, both ASOX enantiomers and (-)-(R)-PZQ. Clinically, the combination of ABZ and PZQ may improve the therapeutic efficacy as a consequence of higher concentration of both active drugs. On the other hand, the magnitude of this elevation may represent an increased risk of side effects, requiring, certainly, reduction of the dosage. However, further studies are necessary to evaluate the efficacy and safety of this combination.

Cannabidiol inhibitory effect on marble-burying behaviour: involvement of CB1 receptors

Cannabidiol (CBD) is a major nonpsychotomimetic component of Cannabis sativa that has been shown to have an anxiolytic effect in human and animal models. Earlier studies suggest that these effects involve facilitation of serotonin, a neurotransmitter that has also been related to obsessive-compulsive disorder. On the basis of this evidence, this study investigated the effects of CBD in C57BL/6J mice submitted to the marble-burying test (MBT), an animal model proposed to reflect compulsive behaviour. CBD (15, 30 and 60 mg/kg) induced a significant decrease in the number of buried marbles compared with controls (34, 41 and 48%, respectively). A similar, although larger, decrease was also found after the serotonin selective reuptake inhibitor paroxetine (10 mg/kg, 77% decrease) and the benzodiazepine diazepam (2.5 mg/kg, 84% decrease). The effect of CBD (30 mg/kg) was still significant after 7 days of daily repeated administration, whereas the effect of diazepam disappeared. Pretreatment with WAY100635 (3 mg/kg), a 5HT1A receptor antagonist, prevented the effects of paroxetine but failed to alter those of CBD. These latter effects, however, were prevented by pretreatment with the CB1 receptor antagonist AM251 (1 mg/kg). These results indicated that CBD and paroxetine decrease the number of buried marbles in the MBT through distinct pharmacological mechanisms. They also suggest a potential role of drugs acting on the cannabinoid system in modulating compulsive behaviour. Behavioural Pharmacology 21: 353-358 (C) 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins.

Is Suppression of Hypothalamic-Pituitary-Adrenal Axis Significant During Clinical Treatment of Phimosis?

Purpose: Corticoids have been an option for phimosis treatment since 1993. However, long-term use or repeated cycles pose a concern regarding drug absorption and consequent systemic effects. The aim of this study was to investigate the effect of topical corticoids used in treating phimosis on the hypothalamus-pituitary-adrenal axis in children. Materials and Methods: A total of 31 children were included in the study. Cortisol secretion was evaluated by the measurement of salivary cortisol in saliva samples collected at 9:00 a.m, before starting treatment and after 8 weeks of topical treatment with 0.05% clobetasol propionate. Salivary cortisol was determined by radioimmunoassay. To confirm that use of clobetasol propionate was not detected by the assay, the presence of cortisol circadian rhythm was checked by an extra saliva sample obtained at 11:00 p.m. from 10 children, and was observed to be maintained in all of them. Results: No significant difference in salivary cortisol levels was observed between samples obtained at 9:00 a.m. before starting treatment and after completing treatment when the entire group was analyzed. However, in 2 children the salivary cortisol levels after treatment were lower than the cutoff value (358 ng/dl) assumed to be suggestive of hypothalamus-pituitary-adrenal axis suppression. Conclusions: Topical clobetasol propionate used twice daily for clinical treatment of phimosis does not affect the hypothalamus-pituitary-adrenal axis in most patients. However, salivary cortisol level should be considered as a laboratory marker in long-term treatment or during repeated cycles to detect possible hypothalamus-pituitary-adrenal axis suppression.

Serial conditional discrimination and temporal bisection in rats selectively lesioned in the dentate gyrus

In positive serial conditional discrimination, animals respond during a target stimulus when it is preceded by a feature stimulus, but they do not respond when the same target stimulus is presented alone. Moreover, the feature and target stimuli are separated from each other by an empty interval. The present work aimed to investigate if two durations (4 or 16s) of the same feature stimulus (light) could modulate the operant responses of rats to different levers (A and B) during a 5-s target stimulus (tone). In the present study, lever A was associated with the 4-s light, and lever B was associated with the 16-s light. A 5-s empty interval was included between the light and the tone. In the same training procedure, the rats were also presented with the 5-s tone without the preceding light stimuli. In these trials, the responses were not reinforced. We evaluated the hippocampal involvement of these behavioral processes by selectively lesioning the dentate gyrus with colchicine. Once trained, the rats were submitted to a test using probe trials without reinforcement. They were presented with intermediate durations of the feature stimulus (light) to obtain a temporal bisection curve recorded during the exposure to the target stimuli. The rats from both groups learned to respond with high rates during tones preceded by light and with low rates during tones presented alone, which indicated acquisition of the serial conditional discrimination. The rats were able to discriminate between the 4- and 16-s lights by correctly choosing lever A or B. In the test, the temporal bisection curves from both experimental groups showed a bisection point at the arithmetic mean between 4 and 16s. Such processes were not impaired by the dentate gyrus lesion. Thus, our results showed that different durations of a feature stimulus could result in conditional properties. However, this processing did not appear to depend on the dentate gyrus alone. (C) 2011 Published by Elsevier B.V.

Cutaneous mycoflora and CD4:CD8 ratio of cats infected with feline immunodeficiency virus

This study was designed to compare cutaneous mycoflora isolation and CD4+:CD8+ ratio in feline immunodeficiency virus (FIV)-infected cats with that in FIV-uninfected cats. Sixty cats were examined. Twenty-five were Fly-infected cats and 35 were RV-uninfected cats. All 60 cats were FeLV-negative. Fungi were speciated and immunophenotyping of peripheral CD4+ and CD8+ T lymphocytes was performed. At least one fungal colony was isolated from 22/25 (88%) FIV-infected cats. Among the FIV-uninfected cats fungal colonies were recovered from 13/35 (37%) specimens. Dermatophytes were recovered from 2/25 (8%) FIV-infected cats (one Microsporum gypseum, one Microsporum can is) and 3/35 (8.5%) FIV-uninfected cats (M gypseum). Malassezia species was the most commonly isolated organism from both groups of cats (51.6%). Malassezia species was more commonly isolated from FIV-infected cats than RV-uninfected cats (84% vs 28.6%). The CD4+ to CD8+ lymphocyte ratio for FIV-infected cats was significantly lower than the CD4+ to CD8+ ratio in the FIV-uninfected cats. The CD4+ to CD8+ lymphocyte ratio for FIV-infected cats with cutaneous overall fungal isolation was significantly lower than the CD4:CD8 lymphocyte ratio in the FIV-infected cats but without cutaneous fungal isolation. We can conclude that immunologic depletion due to retroviral infection might represent a risk factor to cutaneous fungal colonization in cats. (C) 2010 ISFM and AAFP. Published by Elsevier Ltd. All rights reserved.

Effects of sperm concentration and straw volume on motion characteristics and plasma, acrosomal, and mitochondrial membranes of equine cryopreserved spermatozoa

The advantages of using cryopreserved semen in equine reproduction are well known. During cryopreservationl spermatozoa undergo many changes that lead to a decrease in fertility. There is no agreement on the ideal sperm dose and concentration to maximize fertility rates. Thus, the objectives of this experiment were to evaluate sperm motion by computer-assisted analysis (CASA), sperm membrane integrity and function with fluorescence probes of cryopreserved sperm at three concentrations: 100 (C100), 200 (C200) and 400 x 10(6) sperm/mL (C400), and two straw volumes (0.50 and 0.25 mL). There was no interaction between sperm concentration and storage volume (P > .05). Sperm motion characteristics were influenced by concentration (C100 > C200 > C400; P < .05). Curvilinear velocity (VCL) in 0.25-mL straws had higher average values (P < .05). Membrane integrity and function were not changed by straw volume (P > .05). However, sperm concentration changed the percentage of cells with intact plasma membrane (C100 > C200 > C400; P < .05) and the percentage of cells with high mitochondrial membrane potential (C100 = C200; P > .05 and C400 < C100 and C200; P < .05). According to this experiment, the best freeing method was that involving 100 x 10(6) sperm/mL, regardless of straw volume.

Influence of Blood Contamination on Bond Strength of a Self-etching Adhesive to Dental Tissues

Purpose: The aim of this study was to detect the influence of (1) storage period of heparinized blood, (2) type of blood and presence of contaminant, (3) application mode of cleansing agents, and (4) efficacy of cleansing agents on contaminated enamel and dentin during the adhesion process of a one-step adhesive system. Materials and Methods: One hundred four human molars were sectioned into halves along the long axis for enamel and dentin tests. Heparinized and fresh blood were obtained from the same donor, applied and dried to maintain a layer of dry blood on the top of samples. The cleansing agents used were hydrogen peroxide, anionic detergent, and antiseptic solution. A one-step adhesive system (Clearfil S3 Bond) was applied on the dental surface, and composite resin cylinders were built up using Tygon tubing molds. After 24 h, the mu SBS test (1 mm/min) and fracture analysis were performed. Results: There was no statistically significant difference in bond strength values regarding the storage period of heparinized blood and the types of blood. Groups without contamination presented higher bond strengths than contaminated groups. The application mode of the cleansing agents had no influence on bond strength results. There was no statistically significant difference among cleansing agents and they were as effective as a water stream in counteracting the effect of blood contamination. Conclusion: Heparinized blood can be used as a contaminant for up to one week, and it is a reliable procedure to standardize the contaminant. The cleansing agents can be used without friction. A water stream is sufficient to remove blood contamination from dental tissues, before the application of a one-step adhesive system.

Assessment of the Availability of Bone Volume for Grafting in the Donor Retromolar Region Using Computed Tomography: A Pilot Study

Purpose: The purpose of this study was to evaluate the area and volume of bone available for grafting in a donor retromolar region using computed tomography (CT). Materials and Methods: Ten patients previously scanned by multislice CT were selected for evaluation. Images from partially and completely dentate patients at least 18 years of age were included in the study; those from patients with impacted or erupted third molars or intrabony lesions in the study area were not included. Computer software with appropriate tools was used to handle the images. Two calibrated observers made measurements separately. Safety margins in relation to the lingual cortex, the base of mandible, and the alveolar canal were established in each cross-section of the CTs. Measurements were done by using cross-sectional views, and the results were calculated after three-dimensional reconstruction, providing area and volume data. Results: The mean area of bone available for grafting was 8.12 cm(2) ( range, 0.00 to 13.60 cm(2)) and 8.32 cm(2) ( range, 0.00 to 14.30 cm(2)) for observers 1 and 2, respectively. Mean available bone volume for grafting was 0.79 cm(3) ( range, 0.00 to 1.50 cm(3)) for observer 1 and 0.85 cm(3) ( range, 0.00 to 1.60 cm(3)) for observer 2. Interobserver analysis showed substantial agreement. Conclusion: The retromolar region showed a wide variety of anatomic differences among patients. Three-dimensional multislice CT allows reproducible measurements of the area and volume of the retromolar region. Int J Oral Maxillofac Implants 2010; 25: 374-378

Understanding the impact of divalent cation substitution on hydroxyapatite: An in vitro multiparametric study on biocompatibility

Hydroxyapatite (HA), a stable and biocompatible material for bone tissue therapy, may present a variable stoichiometry and accept a large number of cationic substitutions. Such substitutions may modify the chemical activity of HA surface, with possible impact on biocompatibility. In this work, we assessed the effects of calcium substitution with diverse divalent cations (Pb(2+), Sr(2+), Co(2+), Zn(2+), Fe(2+), Cu(2+), or Mg(2+)) on the biological behavior of HA. Physicochemical analyses revealed that apatite characteristics related to crystallinity and calcium dissolution/uptake rates are very sensitive to the nature of cationic substitution. Cytocompatibility was evaluated by mitochondrial activity, membrane integrity, cell density, proapoptotic potential, and adhesion tests. With the exception of Zn-HA, all the substituted HAs induced some level of apoptosis. The highest apoptosis levels were observed for Mg-HA and Co-HA. Cu-HA was the only material to impair simultaneously mitochondrial activity, membrane integrity, and cell density. The highest relative cell densities after exposure to the modified HAs were observed for Mg-HA and Zn-HA, while Co-HA significantly improved cell adhesion onto HA surface. These results show that changes on surface dissolution caused by cationic substitution, as well as the increase of metal species released to biological media, were the main responsible factors related to alterations on HA biocompatibility. (C) 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 98A: 351-358, 2011.

Expression of vascular endothelian growth factor-C does not predict occult lymphnode metastasis in early oral squamous cell carcinoma

Strong vascular endothelial growth factor-C (VEGF-C) expression has been correlated to occurrence of lymph-node metastases in patients with oral squamous cell carcinoma (OSCC). The incidence of occult lymph-node metastasis remains a decisive factor in the prognosis of patients with early OSCC. The aim of this study was to evaluate VEGF-C expression as a predictor of occult lymph-node metastasis in OSCC. Eighty-seven patients with primary OSCC arising in the tongue or floor of mouth, clinically T1N0M0 or T2N0M0, with (pN+) and without (pN0) occult lymph-node metastases were analyzed for VEGF-C expression by malignant cells. Occult lymph-node metastases (pN+) were detected in 22% of the 64 patients who were submitted to elective neck dissection. No statistically significant difference was found between OSCC with and without occult lymph-node metastasis in regard to VEGF-C immunoexpression by malignant cells and clinicopathologic features. Independently of VEGF-C expression, lymph-node metastasis (PN+) was the most significant prognostic factor for overall survival of patients with OSCC (p = 0.030). These findings indicate that isolated VEGF-C expression by malignant cells is not of predictive value for occult lymph-node metastasis in the early stages of OSCC.

GABAergic antagonist blocks the reduction of tonic immobility behavior induced by activation of 5-HT(2) receptors in the basolateral nucleus of the amygdala in guinea pigs

Tonic immobility (TI) is a temporary state of profound motor inhibition induced by situations that generate intense fear, with the objective of protecting an animal from attacks by predators. A preliminary study by our group demonstrated that microinjection into the basolateral nucleus of the amygdala (BLA) of an agonist to 5-HT(1A) and 5-HT(2) receptors promoted a decrease in TI duration. In the current study, the effects of GABAergic stimulation of the BLA and the possible interaction between GABA(A) and 5-HT(2) receptors on TI modulation were investigated. Observation revealed that GABAergic agonist muscimol (0.26 nmol) reduced the duration of TI episodes, while microinjection of the GABAergic antagonist bicuculline (1 nmol) increased TI duration. Additionally, microinjection of 5-HT(2) agonist receptors (alpha-methyl-5-HT, 0.32 nmol) into the BLA decreased TI duration, an effect reversed by pretreatment with bicuculline (at the dose that had no effect per se, 0.2 nmol). Moreover, the activation of GABA(A) and 5-HT(2) receptors in the BLA did not alter the spontaneous motor activity in the open field test. These experiments demonstrated that the activation of GABA(A) and 5-HT(2) receptors of the BLA possibly produce a reduction in unconditioned fear that decreases the TI duration in guinea pigs, but this is not due to increased spontaneous motor activity, which could affect a TI episode nonspecifically. Furthermore, these results suggest an interaction between GABAergic and serotoninergic mechanisms mediated by GABA(A) and 5-HT(2) receptors. In addition, the GABAergic circuit of the BLA presents a tonic inhibitory influence on TI duration. (C) 2009 Elsevier Inc. All rights reserved.

Effect of Chelating Solutions on the Microhardness of Root Canal Lumen Dentin

Introduction: The greatest reduction in microhardness of the most superficial layer of dentin of the root canal lumen is desired. The use of chelating agents during biomechanical preparation of root canals removes smear layer, increasing the access of the irrigant into the dentin tubules to allow adequate disinfection, and also reduces dentin microhardness, facilitating the action of endodontic instruments. This study evaluated the effect of different chelating solutions on the microhardness of the most superficial dentin layer from the root canal lumen. Methods: Thirty-five recently extracted single-rooted maxillary central incisors were instrumented, and the roots were longitudinally sectioned in a mesiodistal direction to expose the entire canal extension. The specimens were distributed in seven groups according to the final irrigation: 15% EDTA, 10% citric acid, 5% malic acid, 5% acetic acid, apple vinegar, 10% sodium citrate, and control (no irrigation). A standardized volume of 50 mu L of each chelating solution was used for 5 minutes. Dentin microhardness was measured with a Knoop indenter under a 10-g load and a 15-second dwell time. Data were analyzed statistically by one-way analysis of variance and Tukey-Kramer multiple-comparison test at 5% significance level. Results: EDTA and citric acid had the greatest overall effect, causing a sharp decrease in dentin microhardness without a significant difference (p > .05) from each other. However, both chelators differed significantly from the other solutions (p < .001). Sodium citrate and deionized water were similar to each other (p > .05) and did not affect dentin microhardness. Apple vinegar, acetic acid, and malic acid were similar to each other (p > .05) and presented intermediate results. Conclusion: Except for sodium citrate, all tested chelating solutions reduced microhardness of the most superficial root canal dentin layer. EDTA and citric acid were the most efficient. (J Endod 2011;37:358-362)