68 research outputs found
Fish Community Structure and Food Web Dynamics in Low Rainfall Mangrove and Non-mangrove Ecosystems (Persian Gulf)
Mangroves are considered as an important source of nutrition to aquatic consumers, which, in return, sustain the fish population. However, there is still controversy about the importance of mangroves to fish communities, and furthermore, not all mangroves fulfill every function ascribed to them. The Persian Gulf presents the northernmost mangroves in the Indo-Pacific region, thriving under extreme environmental conditions such as very low rainfall and high salinities. Very few studies have addressed fish distribution patterns of mangroves in this arid region. The main objective of this study is to describe and compare the fish community structure and food web dynamics of mangrove and non-mangrove intertidal creeks in a low-rainfall system in Qeshm Island, Persian Gulf, Northern Indian Ocean (26.8°N, 55.75°E). Therefore, this thesis addresses temporal changes in mangrove fish assemblages related to the tidal and diel cycles in the meso-tidal mangrove of Qeshm Island. Also, the food webâ s dynamics were studied to determine the role of mangroves in fish food webs. Moreover, due to the arid climate along the northern Indian Ocean, many neighboring creeks are devoid of mangroves but still provide habitat for fish. This provided the necessary conditions for a natural experiment to compare fish assemblage structures and trophic diversity between creeks that are mangrove lined, and creeks without mangroves across seasons. For that, fish were collected with respect to the different combinations of tidal amplitude (and lunar phase) and day light conditions as well as seasons (winter, summer). Also, various potential food sources were collected for à ´13C and à ´15N measurements from both habitats across seasons. The findings show the impact of environmental variables (e.g. tide and temperature) in structuring fish assemblages in Qeshm intertidal creeks. The interaction between tide and time of day emerged as an important factor in organizing mangrove fish assemblages in this meso-tidal arid region. The highest fish biomass, abundance, and diversity were observed during spring tide night. High inundation during spring tides coinciding with the darkness provided the most favorable conditions for fish. When mangrove fish communities were compared with the non-mangroves, seasonality appeared as a more important factor than habitat. Extreme summer water temperatures (>33°C) likely limit the fish abundances and biomass. Fish assemblages of mangrove and non-mangrove intertidal creeks were equally diverse and dominated by the same fish families (e.g. Mugilidae). Small-sized fish dominated catches in both habitats. Also, there were no consistent differences in fish abundance and biomass for mangrove vs. non-mangrove fish collections. Community trophic diversity, measured with size-corrected standard ellipse areas (SEAc), also showed no significant difference across habitats. Instead, strong seasonal patterns were observed for the food sources and fish communities isotopic niche sizes. These findings demonstrate that the structuring effect of seasonality is more important than habitat in determining the fish distribution patterns in this region. Mangrove-derived organic matter contributed to a maximum of 36% to the fish tissue, whereas organic matter produced by microphytobenthos and plankton plays a major role in the diets of the most abundant fish species, with contributions of 64 - 100%. Thus, the fish food webâ s support of mangrove and non-mangrove intertidal creeks seems to be energetically driven by pelagic and benthic food pathways in this study area. Furthermore, the dominance of detritivores in both mangrove and non-mangrove intertidal creeks suggests the importance of benthic food webs in the intertidal creeks at Qeshm Island. The outcomes of this dissertation contribute to the global understanding of the importance of mangrove and non-mangrove intertidal creeks for fish food webs and fisheries support in a low-rainfall coastal ecosystem. The findings imply some potentially interesting consequences on habitat conservation and indicate that the abundance of small fish is not always higher in complex vegetation. Like mangrove creeks, the bare creeks are utilized by a wide variety of fish, suggesting greater attention should be drawn to these habitats
Outcomes of orbital decompression for thyroid eye disease over a 10-year period at a tertiary eye care referral center
Background: Orbital decompression is frequently indicated to treat exophthalmos and compressive optic neuropathy, among other indications for thyroid eye disease (TED). This study aimed to evaluate the outcomes of orbital decompression and compare the results by urgency and type of surgery in patients with TED.
Methods: In this cross-sectional study, we recruited patients with TED who had undergone emergency or elective orbital decompression surgery at a tertiary eye care referral center in Tehran, Iran, between 2010 and 2020. Ophthalmic examination findings, demographic and clinical profiles, and types and outcomes of surgical interventions were reviewed and analyzed.
Results: Fifty-one orbits of 35 patients with a mean (standard deviation [SD]) age of 36.2 (12.0) years and male-to-female ratio of 23 (66%)/12 (34%) were included. The mean (SD) duration from the diagnosis to the surgery was 41.0 (39.0) months. The surgical method was fat decompression in 1 (2%) orbit; fat and inferior wall decompressions in 2 (4%) orbits; fat, inferior, and medial wall (two-wall) decompressions in 43 (84%) orbits; and fat, inferior, medial, and lateral wall (three-wall) decompressions in five (10%) orbits. Three-wall decompression surgery resulted in significantly lower exophthalmometry readings than those associated with two-wall surgery at all postoperative follow-ups (P < 0.05). Ten (20%) orbits required emergency decompression because of sight-threatening conditions and revealed comparable exophthalmometry readings with electively decompressed orbits at the 1-year visit (P > 0.05). Thirty-seven (73%) orbits required other surgeries within the 1-year follow-up. The mean (SD) exophthalmometry readings before and 1-year after surgery were 26.3 (4.0) and 18.3 (2.7) mm, respectively, with a significant decrease and significant 5.5 (3.3)-mm change from baseline in decompressed orbits (both P < 0.001). Diplopia was reported in 29% (n = 10) of patients less than 2 months postoperatively.
Conclusions: Emergency or elective orbital decompression significantly reduced exophthalmos in patients with TED within 1 year postoperatively. Three-wall orbital decompression produced the more immediate impact, while two-wall orbital decompression showed the higher effect at a later timepoint. The most common complication was diplopia, while other serious complications occurred infrequently. Further prospective comparative studies involving more participants and longer postoperative follow-up periods are required to verify these preliminary findings
Identification of clinical isolates of Acinetobacter baumannii from Iran and study of their heterogeneity
AbstractBackgroundAcinetobacter baumannii has become one of the most serious causative agents of nosocomial infections due to its significant ability to survive on hospital surfaces. It is mainly an emerging opportunistic pathogen infecting patients in intensive care units. This study was aimed to identify the clinical isolates of A. baumannii and to investigate their heterogeneity using polymerase chain reaction (PCR)-based typing methods.MethodsA total of 197 nonduplicate isolates recovered from a wide range of clinical samples were subjected to conventional cultural and biochemical tests. For those isolates that were preliminary identified as A. baumannii, rpoB-based PCR with subsequent restriction fragment length polymorphism (RFLP) using two restriction enzymes (TagI and HaeIII) was performed to investigate the genetic diversity of the strains and their presumptive relationships with different clinical presentation of the disease caused by this pathogen.ResultsIn total, 50 isolates (25.4%) were identified as A. baumannii using conventional phenotypic methods with subsequent confirmation by rpoB sequencing. RFLP analysis demonstrated five different restriction enzyme patterns, designated as A–E clusters. Most A. baumannii isolates were categorized under Cluster A (32%). We found no significant relationship between clinical presentation and the clustering of the isolates.ConclusionThis study showed that the rpoB region possesses high discriminatory power to identify the isolates to the species level. This marker showed high interspecies variability that might be useful for strain typing. The results also suggest the possibility of the existence of a predominant clone of A. baumannii among infected patients in Iran
Antimicrobial activity of endophytic bacterial populations isolated from medical plants of Iran
Endophytic actinobacteria colonize inside the plant tissues without causing damages to the host plant. Since these microorganisms colonize in the different parts of plants and can stop plant disease, they have been applied as biological agents for controlling human diseases. The aim of this study was molecular identification and measuring the antimicrobial activity of endophytic Actinomycetes isolated from medicinal plants of Iran. Materials and Methods: The total of 23 medicinal plant samples were collected, sterilized, and crushed. Small pieces of the crushed samples were then cultured directly on three selective media. Grown colonies were identified by 16S rRNA gene sequencing method. Each isolate was cultured in TSB medium and then antimicrobial compound was extracted using ethyl acetate and tested against the target bacteria. Results: Sixteen out of 23 bacterial isolates (69%) exhibited antimicrobial activity against the selected pathogenic bacteria, such as Bacillus cereus, Staphylococcus aureus, Bacillus subtilis, Klebsiella pneumoniae, Citrobacter freundii, Proteus mi-rabilis, Shigella flexneri and Escherichia coli. Conclusion: Our Study showed a high phylogenetic diversity and the potent antibiotic activity of endophytic bacteria in medicinal plants of Iran. © 2017, Tehran University of Medical Science. All rights reserved
The Effect of Four Months of TRX Training on Lumbar Bone Mineral Density and its Relationship with Serum Adiponectin Level in Osteopenic Women
Background: Osteoporosis is a systemic skeletal disease augmenting the risk of fractures. The biological mechanisms of bone osteogenic response to mechanical loads are not fully understood. This study aimed to determine the effects of four months of TRX training on lumbar bone mineral density (BMD) and its relationship with serum adiponectin in osteopenic women.
Methods: In this quasi-experimental study, 30 osteopenic women were selected by purposive sampling and then randomly divided into two groups of TRX (n=15), and control (n=15). The experimental group performed TRX exercise protocol for four months, three sessions a week, and 45-60 minutes per session. At the beginning and end of the intervention, blood samples were obtained to determine serum adiponectin using a specific ELISA kit (Bio vendor, Czech Republic). The bone mineral density of the lumbar was assessed by 2D Dexa instrument (LEXXOS DIGITAL, USA). Data analysis was performed applying paired and independent sample student t-test and Pearson correlation in SPSS 20 software.
Results: Lumbar BMD (Pvalue=0.000) and serum adiponectin level (Pvalue=0.000) significantly increased in the TRX group compared to the control. In within-group comparison, significant elevations were observed in lumbar BMD (Pvalue=0.000) and serum adiponectin level (Pvalue=0.004) after TRX exercise. A statistically significant positive correlation was observed between lumbar BMD and serum adiponectin in osteopenic women (Pvalue=0.000).
Conclusions: According to the results, it seems that TRX exercise can improve lumbar BMD and serum adiponectin levels in osteopenic women.
Keywords: Osteopenia, TRX exercise, Lumbar bone mineral density, Adiponecti
5-Oxo-hexahydroquinoline derivatives and their tetrahydroquinoline counterparts as multidrug resistance reversal agents
Cancer is a leading cause of death worldwide. Multidrug resistance (MDR) is a main reason of chemotherapy failure in many patients and is often related to overexpression of ATP-binding cassette (ABC) transporters, including P-glycoprotein (P-gp/ABCB1). Agents that are capable of modulation of the activity of these transporters might be effective in overcoming MDR. In this study, a new set of 1,4,5,6,7,8-hexahydro 5-oxo quinoline-3-carboxamide derivatives bearing 4-methylthiazole moiety and their tetrahydroquinoline counterparts were synthesized. MDR reversal activity of these 16 newly synthesized derivatives was tested in P-gp overexpressing MES-SA-DX5 human uterine sarcoma cells by flow cytometric determination of Rhodamine123 efflux. The effect of the most potent compounds in induction of apoptosis and alterations of cell cycle was examined in these cells by a flow cytometric method. Inherent cytotoxicity of the synthesized compounds was evaluated against MCF-7, A-549 and K562 cancer cell lines, as well as MES-SA-DX5 and their parental non-resistant MES-SA and also HEK-293 non-cancerous cells by MTT assay. Compounds A1 and A2 with 5-oxo-hexahydroquinoline structure bearing 2,4-dichlorophenyl and 4-bromophenyl moieties, respectively, and their tetrahydroquinoline counterparts B1 and B2 significantly blocked P-gp efflux, induced apoptosis and showed the highest cytotoxicities against MES-SA-DX5 cells. However, only A2 and B2 compounds were relatively selective against cancer and MDR cells as compared to non-resistant and non-cancerous cells. These findings demonstrate that 5-oxo-hexahydroquinoline and 5-oxo-tetrahydroquinoline derivatives represent promising agents with therapeutic potential in drug resistant cancers
Introducing an efficient model for the prediction of placenta accreta spectrum using the MCP regression approach based on sonography indexes: how efficient is sonography in diagnosing accreta?
Background For the first time, we aimed to introduce a model for prediction of placenta accreta spectrum (PAS), using existing sonography indices. Methods Women with a history of Cesarean sections were included. Participants were categorized "high risk" for PAS if the placenta was previa or low-lying. Sonography indices including abnormal placental lacuna, loss of clear zone, bladder wall interruption, myometrial thinning, placental bulging, exophytic mass, utero-vesical hypervascularity, subplacental hypervascularity, existence of bridging vessels, and lacunar flow, were registered. To investigate simultaneous effects of 15 variables on PAS, Minimax Concave Penalty (MCP) was used. Results Among 259 participants, 74 (28.5%) were high risk and 43 individuals had PASs. All sonography indices were higher among patient with PAS (p < 0.001) in the high risk group. Our model showed that utero-vesical hypervascularity, bladder interruption and new lacunae have significant contribution in PAS. Optimal cut off point was p = 0.51 in ROC analysis. Probability of PAS for women with lacunae was between 96 and 100% and probability of PAS for women without lacunae was between 0 to 7%, therefore accuracy of the proposed model was equal to 100%. Conclusions Using the introduced model based on three factors of abnormal lacuna structures (grades 2 and 3), bladder wall interruption and utero-vesical vascularity, 100% of all cases of PASs are diagnosable. If supported by future studies our model eliminates the need for other imaging assessments for diagnosis of invasive placentation among high risk women Keywords:Morbidly adherent placenta; Placenta accreta spectrum; Ultrasonography; Accreta; Diagnosi
Determination of the Level of Happiness among Students of Shiraz University of Medical Sciences, Iran
Introduction and Objective: The purpose of this study is to determine the level of happiness and vitality as one of the effective factors on increasing students' success in education and spiritual well-being.
Materials and Methods: The present study is a descriptive cross-sectional study. Five hundred and seven students from Shiraz University of Medical Sciences were selected by stratified random sampling and responded to the Oxford Happiness Questionnaire. Data were analyzed using "SPSS 19" software, descriptive and inferential statistics.
Results: The results indicate that mean of happiness among participants was 40.9 +/- 13.1 (ranged from 2 to 87) which was moderate. Also mean score of happiness among males was significantly higher than females (43.5 +/- 15.0 and 40.1 +/- 12.4, p=0.01). Moreover there was no difference in the level of happiness between difference status such as marital (married/single), residence (dormitory/home), field of study (medicine/pharmacology/medical laboratory sciences, and occupational health), and academic degree (bachelor/master/doctorate).
Conclusion: If academic places such as universities include a happy and vital environment, they will have a very influential role in improving the students' educational and cultural level
RELATIONSHIP BETWEEN SELF-ESTEEM AND FIELD OF STUDY AND ITS EFFECT ON ACADEMIC BURNOUT IN STUDENTS OF SHIRAZ UNIVERSITY OF MEDICAL SCIENCES
Medical students are prone to burnout due to high volume and stressful courses and also attending medical centers. Therefore, the present study aimed to investigate the relationship between self-esteem and field of study and its effect on academic burnout in students of Shiraz University of Medical Sciences. This cross-sectional study was conducted on 600 students of Shiraz University of Medical Sciences selected by multi-stage cluster sampling in 2018. Data were analyzed by SPSS (R) software. The mean score of self-esteem in men was higher than that of women and the mean score of burnout in men was lower than that of women, but this difference was not statistically significant. There was no significant difference in the mean of self-esteem among single and married students. Also, the level of academic burnout was significantly lower among married students than single students. There was a significant negative correlation between self-esteem and academic burnout. The results of the regression analysis showed that academic burnout is the only predictor of student self-esteem. The precise and principled planning for medical and paramedical students who are prone to severe academic burnout due to their very difficult educational situation can play an important role in increasing self-esteem in these student
RELATIONSHIP BETWEEN ACADEMIC BURNOUT AND ECONOMIC AND SOCIAL FACTORS WITH LIFE EXPECTANCY IN STUDENTS OF SHIRAZ UNIVERSITY OF MEDICAL SCIENCES
Life expectancy is considered as one of the most important variables affecting the success and adaptability of the environment in students. Therefore, the present study aimed to investigate the variables affecting life expectancy. A sample of 600 students from Shiraz University of Medical Sciences was selected randomly. Demographic, life expectancy, academic burnout questionnaire were used to collect data. Data were analyzed using SPSS (R). The results of this study showed a significant negative relationship between life expectancy and academic burnout. So, with increasing life expectancy, academic burnout declines, and burnout increases with declining life expectancy. Burnout in male students is slightly higher than female students, but this difference was not statistically significant. Also, academic burnout was higher in dormitory students without a car and personal laptop than in other students, but this difference was not statistically significant. The results of one-variable analysis of variance showed that living place is one of the important factors related to the life expectancy of students. So that students who live with the family have a significantly higher life expectancy. Also, academic burnout in married students was significantly higher than single students. According to the findings of the study, the variables of academic burnout and economic, social factors are related to life expectancy. Therefore, effective planning to reduce academic burnout and improve socioeconomic conditions is important for authoritie
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