A Comparative Study of Ex-Vivo Murine Pulmonary Mechanics Under Positive- and Negative-Pressure Ventilation

Increased ventilator use during the COVID-19 pandemic resurrected persistent questions regarding mechanical ventilation including the difference between physiological and artificial breathing induced by ventilators (i.e., positive- versus negative-pressure ventilation, PPV vs NPV). To address this controversy, we compare murine specimens subjected to PPV and NPV in ex vivo quasi-static loading and quantify pulmonary mechanics via measures of quasi-static and dynamic compliances, transpulmonary pressure, and energetics when varying inflation frequency and volume. Each investigated mechanical parameter yields instance(s) of significant variability between ventilation modes. Most notably, inflation compliance, percent relaxation, and peak pressure are found to be consistently dependent on the ventilation mode. Maximum inflation volume and frequency note varied dependencies contingent on the ventilation mode. Contradictory to limited previous clinical investigations of oxygenation and end-inspiratory measures, the mechanics-focused comprehensive findings presented here indicate lung properties are dependent on loading mode, and importantly, these dependencies differ between smaller versus larger mammalian species despite identical custom-designed PPV/NPV ventilator usage. Results indicate that past contradictory findings regarding ventilation mode comparisons in the field may be linked to the chosen animal model. Understanding the differing fundamental mechanics between PPV and NPV may provide insights for improving ventilation strategies and design to prevent associated lung injuries.

Diseased and healthy murine local lung strains evaluated using digital image correlation

Tissue remodeling in pulmonary disease irreversibly alters lung functionality and impacts quality of life. Mechanical ventilation is amongst the few pulmonary interventions to aid respiration, but can be harmful or fatal, inducing excessive regional (i.e., local) lung strains. Previous studies have advanced understanding of diseased global-level lung response under ventilation, but do not adequately capture the critical local-level response. Here, we pair a custom-designed pressure-volume ventilator with new applications of digital image correlation, to directly assess regional strains in the fibrosis-induced ex-vivo mouse lung, analyzed via regions of interest. We discuss differences between diseased and healthy lung mechanics, such as distensibility, heterogeneity, anisotropy, alveolar recruitment, and rate dependencies. Notably, we compare local and global compliance between diseased and healthy states by assessing the evolution of pressure-strain and pressure-volume curves resulting from various ventilation volumes and rates. We find fibrotic lungs are less-distensible, with altered recruitment behaviors and regional strains, and exhibit disparate behaviors between local and global compliance. Moreover, these diseased characteristics show volume-dependence and rate trends. Ultimately, we demonstrate how fibrotic lungs may be particularly susceptible to damage when contrasted to the strain patterns of healthy counterparts, helping to advance understanding of how ventilator induced lung injury develops.

Exploring new therapeutic potentials of curcumin against post-surgical adhesion bands

BACKGROUND

Adhesion band formation is a common cause of morbidity for patients undergoing surgeries. Anti-inflammatory and anti-fibrotic properties of curcumin, a pharmacologically active component of Curcuma longa, have been investigated in several studies. The aim of this study is to explore the therapeutic potential of curcumin in attenuating post-operative adhesion band (PSAB) formation in both peritoneal and peritendinous surgeries in animal models.

METHODS

Bio-mechanical, histological and quantitative evaluation of inflammation, and total fibrosis scores were graded and measured in the presence and absence of phytosomal curcumin.

RESULTS

Results showed that phytosomal curcumin significantly decreased severity, length, density and tolerance of mobility of peritendinous adhesions as well as incidence and severity of abdominal fibrotic bands post-surgery. Curcumin may decrease inflammation by attenuating recruitment of inflammatory cells and regulating oxidant/anti-oxidant balance in post-operative tissue samples. Moreover, markedly lower fibrosis scores were obtained in the adhesive tissues of phytosomal curcumin-treated groups which correlated with a significant decrease in quantity, quality and grading of fibers, and collagen deposition in animal models.

CONCLUSION

These results suggest that protective effects of phytosomal curcumin against PSAB formation is partially mediated by decreasing inflammation and fibrosis at site of surgery. Further studies are needed to investigate the therapeutic potential of this molecule in preventing PSAB.

IMPACT OF COVID-19 ON THYROID FUNCTION: EVIDENCE FROM IRAN

Context

We assessed the association between the severity of COVID-19 and the thyroid function, and the relationship of thyroid hormones with inflammatory markers in COVID-19 patients.

Subjects and methods

This observational study contained 95 COVID-19 patients. The covariates of interest included the thyroid-stimulating hormone (TSH) and the total form of thyroid hormones thyroxine and triiodothyronine. Furthermore, the inflammatory markers including C-reactive protein, erythrocyte sedimentation rate, lactate dehydrogenase (LDH), and lymphocyte were measured. To analyze the data, the t-test, the nonparametric test for comparing the medians, and the Spearman correlation were used.

Results

The median (interquartile range) of ages was equal to 53 (41-66) years old, including 54 men (56.8%). As the severity of COVID-19 progressed from moderate to severe, increasing, though non-significant, trends of thyroid dysfunction were observed, the most remarkable for TSH. The only significant association between thyroid hormones and inflammatory markers was a Spearman correlation of -0.28 between TSH and LDH. Moreover, a direct association was found between the severity of COVID-19 and the LDH levels (p-value<0.001).

Conclusions

A direct relation between the severity of COVID-19 and the LDH level and a reverse association between the LDH level and the thyroid hormone, TSH was obtained.

The therapeutic potential of Panax ginseng and Ginger on postsurgical adhesion band formation

Background:

Peritoneal adhesions (PA) are a common complication of abdominal operations. Previous studies indicate that inhibition of inflammation and fibrosis at sites of peritoneal damage may prevent the development of intra-abdominal adhesions. Zingiber officinalis Roscoe (ginger) and Panax ginseng (p. ginseng) are herbal products with antioxidant and anti-inflammatory effects which can have restorative properties.

Objective:

This research aimed to examine the impact of ginger and p. ginseng on prevention of PA in a rat model after surgery.

Methods:

Following a laparotomy, the wall of the cecum was rubbed to induce intra-abdominal adherence in Wistar rats. Ginger (400mg/kg) and p. ginseng (500mg/kg) were administered to the animals. The animals were sacrificed on 10 days after surgery, and the Nair and Leach scoring system was used to assess adhesion. The microscopic histology of the induced cecal adhesions was evaluated. An enzyme-linked immunosorbent assay (ELISA) was used to determined tissue levels of transforming growth factor-beta (TGF-β) on homogenized PA tissue. Real-time PCR was performed to quantify the mRNA expression of IL-1β, TNF-α, Col 1a1, and Col 3a1 in rat tissue.

Result:

The adhesion score and histopathological rating based on the Nair and Leach scoring criteria showed lower adhesion scores in the group of rats treated with p. ginseng compared to the control group (P<0.05). Treatment with ginger and p. ginseng was associated with reduced tissue level of TGF-β and mRNA expression of TNF-α and IL-1β. The gene expression level of Col 1a1 and Col 3a1 were markedly decreased in the p. ginseng group.

Conclusion:

The study's outcome recommends that p. ginseng could be an effective agent for preventing the PA and inflammation during the post-operative stage.

Mebendazole, an anti-helminth drug, suppresses inflammation, oxidative stress and injury in a mouse model of ulcerative colitis

Mebendazole (MBZ) is an efficacious anthelmintic with known anti-inflammatory and fibrinolytic properties. In this study, we aimed to explore the protective effects of this FDA-approved drug against DSS-induced colitis in a murine model either alone or in combination with Sulfasalazine (SSZ), a standard therapy for ulcerative colitis. We found that MBZ significantly improved colitis disease activity index as assessed by changes in body weight, degree of stool consistency, rectal bleeding, and prolapse. We also found that MBZ ameliorated the colon histopathological score by attenuating crypt loss, mucosal damage, and inflammation score in colitis tissues. Similarly, DSS-induced colon shortening, colon weight loss, and increase in spleen weight were all abrogated in the presence of MBZ. Moreover, MBZ decreased inflammation, possibly by reducing oxidative stress markers, suppressing inflammatory cell infiltration, and down-regulation of inflammatory genes in colon tissues. Furthermore, MBZ potently reduced fibrosis by decreasing collagen deposition and down-regulating pro-fibrotic genes including Col 1a1 and Col 1a2 in colitis tissue homogenates. In conclusion, our study showed that this broad-spectrum anthelminthic could be repurposed as a novel therapy for ulcerative colitis without any observed side effects, however, regarding the concerns about the potential toxicity of MBZ in UC patients, future experiments on MBZ therapy in other models of UC is needed to completely address the toxicity concerns.

Mouse lung mechanical properties under varying inflation volumes and cycling frequencies

Respiratory pathologies alter the structure of the lung and impact its mechanics. Mice are widely used in the study of lung pathologies, but there is a lack of fundamental mechanical measurements assessing the interdependent effect of varying inflation volumes and cycling frequency. In this study, the mechanical properties of five male C57BL/6J mice (29–33 weeks of age) lungs were evaluated ex vivo using our custom-designed electromechanical, continuous measure ventilation apparatus. We comprehensively quantify and analyze the effect of loading volumes (0.3, 0.5, 0.7, 0.9 ml) and breathing rates (5, 10, 20 breaths per minute) on pulmonary inflation and deflation mechanical properties. We report means of static compliance between 5.4–16.1 µl/cmH₂O, deflation compliance of 5.3–22.2 µl/cmH₂O, percent relaxation of 21.7–39.1%, hysteresis of 1.11–7.6 ml•cmH₂O, and energy loss of 39–58% for the range of four volumes and three rates tested, along with additional measures. We conclude that inflation volume was found to significantly affect hysteresis, static compliance, starting compliance, top compliance, deflation compliance, and percent relaxation, and cycling rate was found to affect only hysteresis, energy loss, percent relaxation, static compliance and deflation compliance.

Examining lung mechanical strains as influenced by breathing volumes and rates using experimental digital image correlation

BACKGROUND

Mechanical ventilation is often employed to facilitate breathing in patients suffering from respiratory illnesses and disabilities. Despite the benefits, there are risks associated with ventilator-induced lung injuries and death, driving investigations for alternative ventilation techniques to improve mechanical ventilation, such as multi-oscillatory and high-frequency ventilation; however, few studies have evaluated fundamental lung mechanical local deformations under variable loading.

METHODS

Porcine whole lung samples were analyzed using a novel application of digital image correlation interfaced with an electromechanical ventilation system to associate the local behavior to the global volume and pressure loading in response to various inflation volumes and breathing rates. Strains, anisotropy, tissue compliance, and the evolutionary response of the inflating lung were analyzed.

RESULTS

Experiments demonstrated a direct and near one-to-one linear relationship between applied lung volumes and resulting local mean strain, and a nonlinear relationship between lung pressures and strains. As the applied air delivery volume was doubled, the tissue surface mean strains approximately increased from 20 to 40%, and average maximum strains measured 70-110%. The tissue strain anisotropic ratio ranged from 0.81 to 0.86 and decreased with greater inflation volumes. Local tissue compliance during the inflation cycle, associating evolutionary strains in response to inflation pressures, was also quantified.

CONCLUSION

Ventilation frequencies were not found to influence the local stretch response. Strain measures significantly increased and the anisotropic ratio decreased between the smallest and greatest tidal volumes. Tissue compliance did not exhibit a unifying trend. The insights provided by the real-time continuous measures, and the kinetics to kinematics pulmonary linkage established by this study offers valuable characterizations for computational models and establishes a framework for future studies to compare healthy and diseased lung mechanics to further consider alternatives for effective ventilation strategies.

The effect of CASP3 rs4647610 and rs4647602 polymorphisms on tumour size and cancer stage in papillary thyroid carcinoma

BACKGROUND

Papillary thyroid carcinoma (PTC) is the most frequent form of thyroid cancer whose incidence has increased in recent years. Dysregulated apoptosis is known in the pathogenesis of various cancers. Caspase-3 is an important apoptotic component and its abnormal function may play a key role in cancer pathogenesis. We tested the hypothesis of a link between CASP3 single nucleotide polymorphisms rs4647610 and rs4647602 on PTC and its clinical outcomes.

MATERIAL AND METHODS

A total of 134 PTC patients and 151 healthy controls were genotyped for CASP3 rs4647610 and rs4647602 single nucleotide polymorphisms (SNPs) using PCR-RFLP method.

RESULTS

Allele and genotype frequencies of both SNPs were not different between cases and controls. The combined genotypes and haplotypes were not linked to PTC. However, the frequencies of CASP3 rs4647610 GA and AA genotypes were higher in PTC patients with larger tumour size (≥1 cm), and the rs4647610 SNP was associated with increased tumour size in the dominant model (OR 3.4 [95% CI, 1.1-11], P = 0.04). The CASP3 rs4647602CA and AA genotypes were higher in PTC patients with lower TNM stage (I-II) compared to higher stages (III-IV). No association was observed between CASP3 polymorphisms and other PTC outcomes.

CONCLUSION

Although CASP3 rs4647610 and rs4647602 SNPs are not associated with PTC, rs4647610 is linked to larger tumour size, and rs4647602 to lower stage of cancer.

The effects of the genetic polymorphisms of antioxidant enzymes on susceptibility to papillary thyroid carcinoma

Several lines of evidences have indicated that inflammation play an important role in the carcinogenesis. During the inflammatory processes, free radical species are produced from oxidative stress. In normal conditions, enzymatic and nonenzymatic antioxidants remove these products. Manganese superoxide dismutase (MnSOD), glutathione peroxidase-1 (GPx-1), and catalase (CAT) are three important enzymes. Therefore, this study aimed to evaluate the effects of MnSOD (SOD2), GPX-1, and CAT genetic polymorphisms on papillary thyroid carcinoma (PTC) susceptibility. A total of 134 patients with PTC and 151 healthy controls were recruited to participate in this study. All samples were genotyped for SOD2 rs4880, GPX1 1050450, and CAT rs7943316 polymorphisms by polymerase chain reaction-restriction fragment length polymorphism method. The frequencies of the rs1050450, rs4880, and rs7943316 alleles and genotypes were not different between PTC patients and controls. However, the TC genotype of SOD2 rs4880 polymorphism was significantly higher in males compared to that in females in PTC patients (odds ratio [OR], 3.9 [95% CI, 1.5-11], p = .007). The rs4880 polymorphism was also associated with higher stages (III-IV) of PTC in dominant model. No significant correlation was found between GPX1-rs1050450 and CAT-rs7943316 polymorphisms and demographic, clinical, and pathological features of the disease. The SOD2 rs4880CT genotype was more frequent in males with PTC and patients with higher stages (III-IV) of disease (OR, 2.9 [95% CI, 1.1-7.7], p = .04). However, no significant association was found between GPX1-rs1050450 and CAT-rs7943316 variants and PTC or its demographic, clinical, and pathological features.

Genetic and epigenetic analysis of the BAX and BCL2 in the placenta of pregnant women complicated by preeclampsia

The current study examined the effects of BAX and BCL2 polymorphisms and methylation as well as mRNA expression on susceptibility to PE. After delivery, the placentas were collected from 92 women with PE, as well as 106 normotensive pregnant women. The BAX rs4645878 and BCL2 rs2279115 polymorphisms were genotyped by the PCR-RFLP method. Methylation-specific PCR (MSP) was used for analysis of promoter methylation. mRNA expression was assayed by Quantitative RT-PCR. In addition, in silico analysis was performed by bioinformatics tools. There was no relationship between PE and placental BAX rs4645878 and BCL2 rs2279115 polymorphisms. The groups were not significantly different regarding the promoter methylation of BAX gene. Nonetheless, the MM status of BCL2 promoter had a significantly higher frequency in the PE group and was associated with 2.7-fold higher risk of PE (OR = 2.7, 95% CI = 1.3-5.6; P = 0.01). The relative mRNA expression of BCL2 was decreased in the placentas of PE women (P < 0.0001). The expression of BAX gene was not significantly different between the two groups. There was no association between placental BAX rs4645878 and BCL2 rs2279115 polymorphisms and mRNA expression levels. In silico analysis indicated that BAX rs4645878 and BCL2 rs2279115 polymorphisms were located in the core recognition site of different transcription factors and these substitutions of wild allele resulted in the loss and/ or change of these binding sites and subsequently may alter BCL2 and BAX expression. This study showed that the BAX and BCL2 polymorphisms and BAX promoter methylation were not associated with PE risk. The BCL2 promoter methylation was associated with lower BCL2 expression and higher PE susceptibility.

The Effects of Concurrent Training Order on Satellite Cell-Related Markers, Body Composition, Muscular and Cardiorespiratory Fitness in Older Men with Sarcopenia

OBJECTIVES

Concurrent Training (CT) is described as a combination of resistance training (RT) and endurance training (ET) in a periodized program to maximize all aspects of physical performance. To date, effects of CT order on muscular and cardiorespiratory fitness adaptations are controversial. Owing to the age-related decrement in satellite cells (SC) which are critical for fiber repair, conservation, muscle hypertrophy as well as cardiorespiratory fitness, the present study examined the response of SC related markers to CT order in older sarcopenic men.

PARTICIPANTS

Thirty older men (age= 64.3 ± 3.5 years) were randomly assigned into one of 3 groups, ET followed by RT (E+R; n=10), RT followed by ET (R+E; n= 10) or a control (C; n=10).

INTERVENTION

The training protocol consisted of 3 exercise sessions per week for 8 weeks. Blood samples were obtained at baseline and 48 hours after the final training session.

RESULTS

Weight, skeletal muscle mass, lower and upper body power, maximal oxygen consumption (VO2max), Paired Box 7 (Pax7), and Myogenic factor 5 (Myf5) significantly increased, while were percent body fat significantly decreased following E+R and R+E compared to C. Importantly, the improvement in skeletal muscle mass, lower and upper body power, Myf5 and Pax7 in the E+R was significantly greater than the R+E group. Myogenin (Myog) and Paired Box 3 (Pax3) significantly increased (P < 0.01) in both training groups compared to no changes in C.

CONCLUSION

An 8-week CT intervention improves SC related markers, body composition and enhances power and VO2max in older sarcopenic participants, regardless of the order of RT and ET. However, performing ET before RT may be more effective at enhancing skeletal muscle mass, Myf5 and Pax7, in addition to both lower and upper body power. While both CT programs produced notable physiological and performance benefits, performing ET before RT during CT may provide the greatest therapeutic benefits for aging individuals.

Genetic polymorphisms of miRNA let7a-2 and pri-mir-34b/c are associated with an increased risk of papillary thyroid carcinoma and clinical/pathological features

microRNAs (miRNAs) as a group of short noncoding RNAs are crucial molecules in transcriptional and translational regulation of oncogenes and tumor suppressor genes. Evidence showed there was an association between the miRNA polymorphisms and various cancers, including papillary thyroid carcinoma (PTC). The present study aims to evaluate the possible effects of let7a-2 rs1143770 and pri-mir-34b/c rs4938723 polymorphisms on PTC susceptibility. A total of 120 patients with PTC and 130 age, sex, and race matched controls were enrolled in the case-control study. The polymerase chain reaction-restriction fragment length polymorphism method was used for genotyping of let7a-2 rs1143770 and pri-mir-34b/c rs4938723 polymorphisms. The let7a-2 rs1143770 CT and TT genotypes were associated with a 1.9-fold and 2.2-fold higher risk of PTC, respectively (P = 0.027 and P = 0.041). Moreover, the let7a-2 rs1143770 polymorphism was associated with increased PTC risk in both dominant (2-fold, P = 0.015) and the allelic model (1.5-fold, P = 0.03). The frequency of pri-mir-34b/c rs4938723TC genotype was significantly higher in patients with PTC and associated with a two-fold higher risk of PTC (P = 0.013). In addition, this polymorphism was associated with a 1.8-fold increased risk of PTC in dominant model (P = 0.021). The let7a-2 rs1143770CT genotype was associated with a 3.5-fold increased risk of N1 stage in PTC patients (P = 0.04), however, pri-mir-34b/c rs4938723TC genotype was associated with a 3.4-fold and 5.1-fold increased risk of III-IV stage and vascular invasion in PTC group, respectively (P = 0.04 and P = 0.04). In conclusion, the present study shows that let7a-2 rs1143770 and pri-mir-34b/c rs4938723 polymorphisms could be susceptible factors for PTC and some clinical features.

Impact of 3D echocardiography on grading of mitral stenosis and prediction of clinical events

Background

The mitral valve orifice area (MVOA) is difficult to assess accurately by 2D echocardiography because of geometric assumptions; therefore, 3D planimetry may offer advantages. We studied the differences in MVOA measurements between the most frequently used methods, to determine if 3D planimetry would result in the re-grading of severity in any cases, and whether it was a more accurate predictor of clinical outcomes.

Methods

This was a head-to-head comparison of the three most commonly used techniques to grade mitral stenosis (MS) by orifice area and to assess their impact on clinical outcomes. 2D measurements (pressure half-time (PHT), planimetry) and 3D planimetry were performed retrospectively on patients with at least mild MS. The clinical primary endpoint was defined as a composite of MV balloon valvotomy, mitral valve repair or replacement (MVR) and/or acute heart failure (HF) admissions.

Results

Forty-one consecutive patients were included; the majority were female (35; 85.4%), average age 55 (17) years. Mean and peak MV gradients were 9.4 (4) mmHg and 19 (6) mmHg, respectively. 2D and 3D measures of MVOA differed significantly; mean 2D planimetry MVOA was 1.28 (0.40) cm², mean 3D planimetry MVOA 1.15 (0.29) cm² (P = 0.003). Mean PHT MVOA was 1.43 (0.44) cm² (P = 0.046 and P < 0.001 in comparison to 2D and 3D planimetry methods, respectively). 3D planimetry reclassified 7 (17%) patients from mild-to-moderate MS, and 1 (2.4%) from moderate to severe. Overall, differences between the two methods were significant (X², P < 0.001). Only cases graded as severe by 3D predicted the primary outcome measure compared with mild or moderate cases (odds ratio 5.7).

Conclusion

3D planimetry in MS returns significantly smaller measurements, which in some cases results in the reclassification of severity. Routine use of 3D may significantly influence the management of MS, with a degree of prediction of clinical outcomes.

Contrast echocardiography in daily clinical practice

Ultrasound contrast agents have unique acoustic properties that enable them to enhance the cardiac blood flow and thus are used broadly in modern echocardiography laboratories for salvage of nondiagnostic studies, improving accuracy and reducing variability even in the presence of adequate image quality. Contrast echocardiography is also used as an adjunctive technique when unenhanced echocardiography falls short in the differentiation of cardiac structural abnormalities such as cardiac masses. Ultrasound contrast agents are pure intravascular tracers. Development of innovative ultrasound imaging techniques has led to myocardial perfusion imaging with contrast echocardiography. Although currently an off-label indication, it has been shown that perfusion imaging with contrast echocardiography adds incremental value to stress echocardiography in the detection of coronary artery disease. Moreover, it can be used for assessment of myocardial viability. In this paper we briefly discuss the basics of contrast echocardiography and its use in daily clinical practice.

Optimizing landfill site selection by using land classification maps

Municipal solid waste disposal is a major environmental concern throughout the world. Proper landfill siting involves many environmental, economic, technical, and sociocultural challenges. In this study, a new quantitative method for landfill siting that reduces the number of evaluation criteria, simplifies siting procedures, and enhances the utility of available land evaluation maps was proposed. The method is demonstrated by selecting a suitable landfill site near the city of Marvdasht in Iran. The approach involves two separate stages. First, necessary criteria for preliminary landfill siting using four constraints and eight factors were obtained from a land classification map initially prepared for irrigation purposes. Thereafter, the criteria were standardized using a rating approach and then weighted to obtain a suitability map for landfill siting, with ratings in a 0-1 domain and divided into five suitability classes. Results were almost identical to those obtained with a more traditional environmental landfill siting approach. Because of far fewer evaluation criteria, the proposed weighting method was much easier to implement while producing a more convincing database for landfill siting. The classification map also considered land productivity. In the second stage, the six best alternative sites were evaluated for final landfill siting using four additional criteria. Sensitivity analyses were furthermore conducted to assess the stability of the obtained ranking. Results indicate that the method provides a precise siting procedure that should convince all pertinent stakeholders.

Evaluation of the antimicrobial effect of conventional and nanosilver-containing varnishes on oral streptococci

STATEMENT OF THE PROBLEM

Nanosilver particles have the potential to serve as a bactericidal agent because of the inherent antimicrobial influences of silver ion. The literature confirmed that specific micro-organisms, especially streptococci, have an important role as an etiological factor for caries.

PURPOSE

The aim of this study was to evaluate the antimicrobial effect of conventional and nanosilver-containing varnishes on oral streptococci.

MATERIALS AND METHOD

Pure cultivations of Streptococcus mutans and Streptococcus salivarius were prepared on blood agar media. Thereafter, 0.5 McFarland standard of recently grown bacteria in normal saline was prepared and the bacteria were cultivated monotonously on the culture medium surface by applying a swab. Different concentrations of nanosilver varnishes were prepared in the Mueller- Hinton broth medium in the test tubes and equal amounts of 0.5 McFarland suspension of all the tested bacteria were added separately to all test tubes. A tube without varnish was included as the control sample. The tubes were kept at 37°C for 24 hours, then cultured to determine the numbers of bacteria in each tube by counting colonies. The numbers of bacteria in tubes with varnish were compared to the numbers of bacteria in the tube without varnish. In the instance of observing any reduction in the growth, the minimum inhibitory concentration for growth in the tube with varnish was determined.

RESULTS

Nanosilver varnish had an antimicrobial effect on S. mutans and S. salivarius.  S. salivarius was more susceptible than S. mutans to the nanosilver varnish.

CONCLUSION

Based on the results of this study, nanosilver varnishes can be used under amalgam restorations to reduce microbial population and subsequently preventing the recurrent caries.

Ultrasonic assisted synthesis of imidazo[1,2-a]azine catalyzed by ZnO nanorods

ZnO nanorods have been successfully used as an efficient, economic, and reusable catalyst for the synthesis of imidazo[1,2-a]azine under ultrasonic irradiation. This procedure offers advantages in terms of higher yields, short reaction times and mild reaction conditions.

The evaluation of Candida albicans biofilms formation on silicone catheter, PVC and glass coated with titanium dioxide nanoparticles by XTT method and ATPase assay

Lots of Candida albicans infections involve in biofilm formation on medical devices. This kind of biofilm can impede antifungal therapy and complicates the treatment of infectious diseases particularly in field of chronic diseases associated with implanted devices. This study has investigated the influence of treating silicone catheter, PVC and glass coated with Titanium dioxide (TiO2) nanoparticles on attachment of C. albicans. In this study TiO2 nanoparticles were synthesized from precursor TiCl4 and characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) which showed TiO2 nanoparticles are 70-100 nm in size. In the simplest model of biofilms formation, C. albicans isolates (ATCC10231) and (ATCC 76615) were grown on the surface of small disks of catheter, PVC and glass in a flat-bottomed 12-well plates and evaluated biofilm formation using ATP bioluminescence and tetrazolium salt (XTT) reduction assays. In addition, morphology of C. albicans biofilms after 48 h incubation was observed by SEM. Results indicated that there is a statistical difference between mean of coated samples especially catheter and glass before and after TiO2 nanoparticles coating (p<0.05). In SEM analysis, C. albicans biofilm was more aggregated on the surface of glass and catheter than PVC and control groups and after treatment by these nanoparticles, catheter and glass both showed most significant decrease of C. albicans attachment in comparison to the control groups (Fig. 4, Ref. 23).

Immunization against leishmaniasis by PLGA nanospheres loaded with an experimental autoclaved Leishmania major (ALM) and Quillaja saponins

Immune responses against the Leishmania antigens are not sufficient to protect against a leishmania challenge. Therefore these antigens need to be potentiated by various adjuvants and delivery systems. In this study, Poly (d,l-lactide-co-glycolide (PLGA) nanospheres as antigen delivery system and Quillaja saponins (QS) as immunoadjuvant have been used to enhance the immune response against autoclaved Leishmania major (ALM). PLGA nanospheres were prepared by a double-emulsion (W/O/W) technique. Particulate characteristics were studied by scanning electron microscopy and particle size analysis. Mean diameter for nanospheres loaded with ALM+QS was 294 ± 106 nm. BALB/c mice were immunized three times in 3-weeks intervals using ALM plus QS loaded nanospheres [(ALM+QS)PLGA], ALM encapsulated with PLGA nanospheres [(ALM)PLGA], (ALM)PLGA + QS, ALM + QS, ALM alone or PBS. The intensity of infection induced by L. major challenge was assessed by measuring size of footpad swelling. The strongest protection, showed by significantly (P < 0.05) smaller footpad, were observed in mice immunized with (ALM)PLGA. The (ALM+QS)PLGA group showed the least protection and highest swelling, while the (ALM)PLGA+QS, ALM+QS and ALM showed an intermediate protection with no significant difference. The mice immunized with ALM and ALM+QS showed the highest IgG2a/IgG1 ratio (P < 0.01), followed by (ALM)PLGA+QS. The highest IFN-γ and lowest IL-4 production was seen in (ALM)PLGA+QS, ALM+QS groups. The highest parasite burden was observed in (ALM)PLGA+QS and (ALM+QS)PLGA groups. It is concluded that PLGA nanospheres as a vaccine delivery system could increase the protective immune responses, but QS adjuvant has a reverse effect on protective immune responses and the least protective responses were seen in the presence of this adjuvant.

Augmentation of shoulder contour using a calf implant

Sprengel deformity is a rare orthopedic condition that is associated with functional and cosmetic impairment. Results of orthopedic procedures are usually inconsistent and cosmetic results are far from satisfactory in these patients. A silicone-gel-filled calf prosthesis was used to correct the shoulder contour in a patient with Sprengel deformity. Cosmetically the deformity can be restored by using a calf implant for patients in whom orthopedic procedures are not likely to yield a satisfactory outcome.

Identifying the management development needs of senior executives in Iran's teaching hospitals

This research paper reports the findings of the first comprehensive survey of senior executives in Iran's teaching hospitals. It is based on an analysis identifying the continuing professional development (CPD) needs of the total population of the two senior levels of teaching hospitals management-presidents of physician-managers and administrative-managers. Four key areas of management knowledge were selected as the focus of the need identification: operational; financial; human resource; and organization change. The findings reveal a pent up demand for introductory level, formal knowledge in all four areas of management theory, to complement and extend the practical experience they have acquired in managing the complex environment of teaching hospitals. The paper goes on to propose a curriculum design and overall framework of provision to meet these genuinely felt CPD needs.

Fate of endoleaks after endoluminal repair of abdominal aortic aneurysms with the EVT device

OBJECTIVE

we aim to describe our medium-term follow-up of 20 patients with an endoleak following repair of their abdominal aortic aneurysms (AAA) using the Endovascular Technologies (EVT) device.

DESIGN

the experience of one centre in a prospective multicentre phase II trial.

MATERIALS AND METHODS

55 patients with an endovascular repair of their AAA and at least 6 months>> follow-up were reviewed. Intraoperative angiograms, next day duplex scans and computed tomography (CT) images were used to detect endoleaks. Follow-up with CT and duplex was performed at 3, 6, 12 and 24 months. Persistent endoleaks at 6 months were evaluated by angiography and treated by endovascular coiling.

RESULTS

there were three immediate conversions to open procedures. Twenty of 52 (38%) patients had an endoleak identified initially. One patient died from a myocardial infarction and three were not evident any longer by discharge CT. Sixteen endoleaks (31%) were present at discharge. Nine resolved spontaneously by 3-6 months and seven were still persistent at 6 months (14%). Six patients underwent coiling of their leak, all with successful radiographic seal after 1-3 sessions.

CONCLUSIONS

endoleaks are frequent after endovascular AAA repair, but the majority close spontaneously. Coiling of the leaks and radiographic seal can be achieved in all cases still persistent at 6 months. Whether this method is clinically effective awaits further follow-up.

Monokine-induced neutrophil chemotactic factor gene expression in human fibroblasts

Although fibroblasts are important in providing a structural framework for most tissues, they also appear to be active participants in the inflammatory process via the production of specific mediators. The production of inflammatory mediators by fibroblasts is especially important in relation to their strategic location within connective tissue as they may act as a cellular communication bridge between the interstitium and vasculature. In this paper, we demonstrate that fibroblasts may participate in these inflammatory reactions by the production of a neutrophil chemotactic factor (NCF) with characteristics similar to a recently isolated and cloned monocyte-derived NCF. Either tumor necrosis factor-alpha-, interleukin-1 alpha-, or interleukin-1 beta-stimulated fibroblasts showed both a time- and dose-dependent increase in steady-state levels of NCF mRNA and secretion of chemotactic activity. In contrast, lipopolysaccharide and interleukin-6 failed to induce fibroblast-derived NCF. The expression of fibroblast-derived NCF mRNA was first detectable by 30 min poststimulation, whereas chemotactic activity was significantly observed 3-4 h postchallenge. Heat-inactivated monokine (100 degrees C) failed to induce NCF mRNA expression, suggesting that only the active proteins are capable of inducing NCF. Gel filtration analysis using high pressure liquid chromatography indicated peak chemotactic activity with an approximate molecular mass of 8000 daltons. This peak of NCF activity was found to be relatively stable to both heat and trypsin inactivation. Specificity of the fibroblast-derived neutrophil chemotactic activity was demonstrated with inhibition of chemotaxis by the addition of neutralizing antibody directed against recombinant human neutrophil chemotactic factor. These data provide evidence that monokine-treated fibroblasts can synthesize a potent chemotactic agent with molecular and physicochemical characteristics similar to monocyte-derived NCF and that this factor may contribute to neutrophil-mediated disease processes.

In vivo dynamics of murine tumor necrosis factor-alpha gene expression. Kinetics of dexamethasone-induced suppression

Tumor necrosis factor-alpha (TNF) has been implicated as an important, proximal mediator of many of the pathophysiologic effects observed during septic shock. In vitro studies have demonstrated that the glucocorticoid dexamethasone (Dex) will suppress the production of TNF; yet, clinical studies have shown that glucocorticoids are not protective in septic shock. In this paper we described the in vivo effects of lipopolysaccharide (LPS) on the kinetics of local and systemic TNF production, the time dependent expression of TNF mRNA, and the suppression of both TNF mRNA and bioactive protein using a defined treatment protocol of Dex. Peritoneal macrophages were elicited by CBA/J mice in the injection of complete Freunds adjuvant and the mice challenged with an intraperitoneal injection of LPS 2 weeks later. Kinetic studies showed that the peak of TNF production occurred 1 hour post LPS injection and reached a maximum of 775 units/ml within the ascites and 26 units/ml within the plasma. Northern blot analysis of mRNA extracted from peritoneal cells showed a peak of mRNA 30 minutes post LPS challenge. Dose-response studies disclosed that 10 micrograms of LPS/mouse produced maximal TNF within the ascites fluid, and half-maximal stimulation occurred at 70 ng LPS/mouse. Mice treated with Dex in vivo before LPS challenge showed a dramatic reduction in TNF production within both the ascites and plasma, and Northern blot analysis showed a corresponding reduction in the TNF specific mRNA. Further studies revealed that mice treated with 4 mg/kg of Dex intraperitoneally 4 hours before, or at the time of LPS challenge, had dramatic reductions in TNF levels within both the ascites and plasma. However, delaying the treatment only 20 minutes after LPS injection failed to significantly reduce TNF in either compartment. These data may provide a rationale why glucocorticoids are not clinically efficacious in the treatment of septic shock, since there is rapid upregulation of LPS-induced TNF gene expression. By the time patients develop clinical signs and symptoms of septic shock there are already preformed, circulating levels of TNF.