460 research outputs found
Biosynthesis and Characterization of Silver Nanoparticles by Aspergillus Species
Currently, researchers turn to natural processes such as using biological microorganisms in order to develop reliable and ecofriendly methods for the synthesis of metallic nanoparticles. In this study, we have investigated extracellular biosynthesis of silver nanoparticles using four Aspergillus species including A. fumigatus, A. clavatus, A. niger, and A. flavus. We have also analyzed nitrate reductase activity in the studied species in order to determine the probable role of this enzyme in the biosynthesis of silver nanoparticles. The formation of silver nanoparticles in the cell filtrates was confirmed by the passage of laser light, change in the color of cell filtrates, absorption peak at 430 nm in UV-Vis spectra, and atomic force microscopy (AFM). There was a logical relationship between the efficiencies of studied Aspergillus species in the production of silver nanoparticles and their nitrate reductase activity. A. fumigatus as the most efficient species showed the highest nitrate reductase activity among the studied species while A. flavus exhibited the lowest capacity in the biosynthesis of silver nanoparticles which was in accord with its low nitrate reductase activity. The present study showed that Aspergillus species had potential for the biosynthesis of silver nanoparticles depending on their nitrate reductase activity
Chemical composition and antimicrobial activities of the essential oil from Myrtus communis leaves
Abstract: Nosocomial pathogens are associated with increased hospital stay lengths and mortality
rates. Increasing resistance to antibiotics makes the treatment of these infections more difficult. Novel
antimicrobial compounds derived from natural sources may be useful for addressing antiobiotic resistance.
The objective of this study is to determine the chemical composition and antimicrobial activities of essential
oils from Myrtus communis L. (Myrtaceae) leaves against pathogens causing nosocomial infections. The
chemical composition of essential oil from M. communis leaves was analysed by gas chromatography-mass
spectrometry (GC-MS). The antimicrobial activity of the essential oil against bacteria and fungi was evaluated
by broth micro-dilution as per the Clinical and Laboratory Standards Institute (CLSI) methods. GC-MS analysis
revealed that the major constituents of the essential oil were α-pinene (39.2 %), 1,8-cineole (22.0 %), and
linalool (18.4 %). The essential oil exhibited antimicrobial activity against all Gram positive and Gram negative
bacteria with MICs in the range of 0.5-32 μL/mL and 8-64 μL/mL, respectively. MICs for the tested
clinical and standard fungi were in the range of 0.03-16 μL/mL. The essential oil exhibited strong antibacterial
and antifungal activities against all the causative agents of nosocomial infections examined, particularly
against strains with antibiotic resistance. The essential oil from M. communis leaves is a potential source of
novel antimicrobial agents for the treatment of nosocomial infections
Characteristics of Palatal Rugae Patterns as a Potential Tool for Sex Discrimination in a Sample of Iranian Children
Statement of the Problem: Palatal rugae have been considered equivalent to fingerprints, as they are unique to each individual. It has been shown that palatal rugae are associated with specific racial groups and are known to aid sex identification. Due to the lack of any published data on palatal rugae morphology on Iranian children, the present study was performed.
Purpose: The present study aimed to investigate differences in the morphology of individual palatal in a sample of Iranian children. Additionally, it is intended to develop discriminant function to identify sex, based on rugae morphology.
Materials and Method: A total of 120 pre-orthodontic casts were evaluated for different rugae patterns using the Thomas and Kotze classification. The casts were equally distributed between sexes with an age range of 6-12 years. Rugae length, shape, and associated morphology were recorded and the independent t-test and Chi-square test were used to compare the mean and relationship between the attributes. The discriminant function analysis was applied to the data in order to determine the applicability of palatal rugae patterns as an aid for sex identification.
Results: While the total rugae count showed an insignificant difference between the males and females, the rugae count on the right side of the palates showed a significant difference (p= 0.046). The primary rugae were most common in both sexes, followed by the secondary and fragmentary rugae. The most prevalent rugae shape between both sexes was the wavy rugae followed by the curve and straight shapes in males and the straight and curve shapes in females. A significant difference was observed in the number of the curve rugae between the sexes. Discriminant function analysis allowed sex differentiation with an accuracy of 60.8%.
Conclusion: Palatal rugae shapes are unique to each individual and could be used as a potential tool for sex identification. Further research on a larger sample is required to fully confirm the application of this method (e.g. in forensic medicine) as a complementary technique for sex identification
The Application of Palatal Rugae for Sex Discrimination in Forensic Medicine in a Selected Iranian Population
Background: Palatal rugae have been shown to be associated with racial and geographical variations and are known to be useful in sex identification. The present study aimed to assess palatal rugae patterns in a sample Iranian population and to compare the results with those from other studied populations.
Methods: During summer 2017, 130 pre-orthodontic plaster casts from patients aged 17-25 years (65 males and 65 females) were obtained from the Department of Orthodontics, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran. The castes were evaluated using the classification given by Thomas and Kotze followed by recording the rugae lengths and shapes. The data were analyzed with the SPSS statistical software package (version 15.0) using the unpaired t test and Chi-square test. P<0.05 were considered statistically significant. Additionally, discriminant function analysis was applied to determine the applicability of palatal rugae patterns as a tool to aid sex identification.
Results: The rugae count showed an insignificant difference between the Iranian males and females. The primary rugae were most common in both sexes followed by the secondary and fragmentary. Significant differences were observed between the sexes and the number of primary rugae in males (P=0.03) and fragmentary rugae in females (P=0.04) on the left side of the palate. A significant difference in the straight and diverging unification types was observed, which was highest in males (P=0.01) and females (P=0.03), respectively. Discriminant function analysis enabled sex identification with an accuracy of 70%.
Conclusion: Palatal rugae is shown to be an appropriate tool for sex identification in an Iranian population. Further studies with a larger sample size are required for a comprehensive outcome
Evaluation of CAMP-Like Effect, Biofilm Formation, and Discrimination of Candida africana
Candida africana as a species recovered from female genital specimens is highly close to C. albicans. The present study was conducted to discriminate C. africana from presumptive vaginal C. albicans strains by molecular assay and evaluate their hemolysin activity, biofilm formation, and cohemolytic effect (CAMP) with vaginal bacterial flora. A total of 110 stock vaginal C. albicans isolates were examined by HWP1 gene amplification. Hemolysin activity and the ability of biofilm formation were evaluated by blood plate assay and visual detection methods, respectively. Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus agalactiae were used to evaluate the CAMP-like effects in Sabouraud blood agar media. Based on the size of the amplicons (941 bp), all isolates were identified as C. albicans. All samples were able to produce beta-hemolysin. Moreover, 69 out of 110 of the isolates (62.7%) were biofilm-positive, 54 out of 110 Candida isolates (49%) demonstrated cohemolytic effects with S. agalactiae, and 48 out of 110 showed this effect with S. aureus (43.6%). All isolates were CAMP-negative with S. epidermidis. We detected all isolates as Candida albicans and almost half of the isolates were CAMP-positive with S. aureus and S. agalactiae, suggesting that these bacteria increase the pathogenicity of Candida in vaginal candidiasis
Prevalence and Characteristics of Developmental Dental Anomalies in Iranian Orofacial Cleft Patients
Statement of the Problem: Individuals with oral clefts exhibit considerably more dental anomalies than individuals without clefts. These problems could initially be among the symptoms of their disease and/or they may be the side effect of their treatments. Pushback palatoplasty could cause some interference during the development of teeth and result in tooth defects.
Purpose: The study was performed to assess the prevalence and characteristics of developmental dental anomalies in orofacial cleft patients who attended Shiraz Orthodontics Research Center-Cleft Lip and Palate Clinic. We managed to compare dental anomaly traits based on gender and cleft side.
Materials and Method: Eighty out of 121 cleft patients were included in this cross-sectional study. All the patients used pushback palatoplasty in their palate closure surgeries. Intraoral photographs, panoramic and intraoral radiographs, cone-beam computed tomography (CBCT) and dental and medical histories were examined and recorded by two observers. Data were analyzed using SPSS PC version 20.0. The differences in the side of cleft and dental anomalies were compared using the Mann-Whitney test.
Results: The mean age of patients was 14.27 years (SD=5.06). The most frequent cleft type was unilateral cleft lip and palate (50%) followed by bilateral cleft lip and palate (43.75%), cleft palate (2.5%) and cleft lip (1.25%). Male predominance (70%) was observed. 92.5 percent had at least one developmental dental anomaly. The most prevalent anomalies were hypodontia (71.25%) followed by microdontia (30%), root dilacerations (21.25%) and supernumerary teeth (15%).
Conclusion: The most prevalent cleft types were unilateral and bilateral cleft lip and palate with male and left side predominance. Hypodontia, microdontia, dilacerations and supernumerary teeth were the most prevalent developmental dental anomalies among Iranian southwestern cleft patients. The surgical technique used to repair their cleft palate may have played a role in developmental dental defects
Acute contact with profibrotic macrophages mechanically activates fibroblasts via αvβ3 integrin–mediated engagement of Piezo1
Fibrosis—excessive scarring after injury—causes 40% of disease-related deaths worldwide. In this misguided repair process, activated fibroblasts drive the destruction of organ architecture by accumulating and contracting extracellular matrix. The resulting stiff scar tissue, in turn, enhances fibroblast contraction—bearing the question of how this positive feedback loop begins. We show that direct contact with profibrotic but not proinflammatory macrophages triggers acute fibroblast contractions. The contractile response depends on αvβ3 integrin expression on macrophages and Piezo1 expression on fibroblasts. The touch of macrophages elevates fibroblast cytosolic calcium within seconds, followed by translocation of the transcription cofactors nuclear factor of activated T cells 1 and Yes-associated protein, which drive fibroblast activation within hours. Intriguingly, macrophages induce mechanical stress in fibroblasts on soft matrix that alone suppresses their spontaneous activation. We propose that acute contact with suitable macrophages mechanically kick-starts fibroblast activation in an otherwise nonpermissive soft environment. The molecular components mediating macrophage-fibroblast mechanotransduction are potential targets for antifibrosis strategies
Research Article Application of City Development Strategy for Improvement of Informal Settlements in Iran: Case Study of Mouzirj Neighborhood of Babol
Abstract: Informal settlements are an undesirable consequence of the rapid growth of urbanization in contemporary society and a major challenge facing cities, especially in developing countries. The common policy of government disbanding of informal settlements contradicts the basic human right to shelter. A more realistic and humane approach is tolerance and gradual integration of such areas into the established city. In Iran, in parallel with urbanization, the development of informal settlements is a common phenomenon in contemporary cities. The Mouzirj neighborhood on the western edge of the city of Babol is an informal settlement. It faces physical, economic, social, legal and environmental problems. Providing solutions for improvement of Mouzirj will increase safety and bring the neighborhood into compliance with standards for residential neighborhoods. This study used the City Development Strategy (CDS) to improve this informal settlement in Babol. The research used a descriptiveanalytical approach and field studies to determine the strengths, weaknesses, opportunities and threats for the SWOT method and develop suitable strategies for improving the informal settlement. Strategies were prioritized using the Quantitative Strategic Planning Matrix (QSPM) model and the solutions were suggested for improving the region
Emergence of Terbinafine Resistant Trichophyton mentagrophytes in Iran, Harboring Mutations in the Squalene Epoxidase (SQLE) Gene
Introduction: Trichophyton mentagrophytes and T. interdigitale are important causative agents of superficial mycoses, demonstrating emergent antifungal drug resistance. We studied the antifungal susceptibility profiles in Iranian isolates of these two species.
Methods: A total of 96 T. interdigitale and 45 T. mentagrophytes isolates were subjected to molecular typing by ribosomal ITS region. Antifungal susceptibility profiles for terbinafine, griseofulvin, clotrimazole, efinaconazole, luliconazole, amorolfine and ciclopirox were obtained by CLSI broth microdilution method. The squalene epoxidase (SQLE) gene was subjected to sequencing for mutations, if any, in isolates exhibiting elevated MICs for terbinafine.
Results: Luliconazole and efinaconazole showed the lowest MIC values against T. mentagrophytes and T. interdigitale isolates. There were five isolates with terbinafine MICs >= 32 mu g/mL in our sample. They belonged to T. mentagrophytes type VIII and harbored two alternative SQLE gene sequence variants, leading to Phe397Leu and Ala448Thr or Leu393Ser and Ala448Thr substitutions in the enzyme. All terbinafine resistant strains could be inhibited by luliconazole and efinaconazole.
Conclusion: This study documented a step in the global spread of resistance mechanisms in T. mentagrophytes. However, treatment alternatives for resistant isolates were available.
Keywords:Trichophyton mentagrophytes; SQLE; terbinafine; antifungal drug resistance; Ira
A New Regression Model Based on Salivary Biomarkers, Chronological Age and Gender to Predict the Stage of Cervical Vertebral Maturation in Orthodontic Patients
Background: In orthodontics, radiography-based methods are frequently used for the assessment of skeletal maturity. Concerning X-ray exposure hazard, a new objective and less invasive method is needed to identify the optimal orthodontic treatment timing. Purpose: In this study, the pattern of salivary alkaline phosphatase and insulin-like growth factor-1 in the circumpubertal period was investigated. Moreover, new regression models were built to predict skeletal maturity more accurately.Materials and Method: In this cross-sectional study, fifty-five subjects aged 7 to 20 years were enrolled to compare the levels of salivary alkaline phosphatase and insulin-like growth factor-1 at different skeletal maturity stages by using 6-stage cervical vertebral maturation method. Moreover, three new multinomial logistic regression models based on these biomarkers, as well as chronological age, and gender were built to predict the cervical stage. Statistical analysis was performed using SPSS (version 24) software. In addition to descriptive statistics, the Shapiro-Wilk test, the one-way analysis of variance test, the independent Samples T-test, the Pearson correlation coefficient, the Chi-square test, and the overall correct classification rate was performed.Results: A significant difference was observed for salivary alkaline phosphatase and also insulin-like growth factor-1 levels between cervical stages (p< 0.001). The peak level in both salivary alkaline phosphatase and insulin-like growth factor-1 levels was observed at CS3. The levels of these biomarkers had a significant positive correlation with the cervical stages from CS1 to CS3 and a significant negative correlation from CS3 to CS6. Based on the regression model analysis, we found that Model 3´ which combined gender with chronological age, alkaline phosphatase, and insulin-like growth factor-1 had the highest predictive ability (76.4%).Conclusion: The notably larger predictive ability of the new model which combined gender with chronological age, salivary alkaline phosphatase, and salivary insulin-like growth factor-1 might be responsible for the identification of the optimal orthodontic treatment timing in an objective and less invasive manner in healthy growing individuals
- …
