فهرست مطالب

Basic Medical Sciences - Volume:22 Issue:7, 2019
  • Volume:22 Issue:7, 2019
  • تاریخ انتشار: 1398/04/10
  • تعداد عناوین: 17
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  • Ran Xia, Bo Zhang, Xinxin Wang, Qiuying Jia * Pages 710-715
    Objective(s)
    The present paper aims to review the studies describing the interactions between HopQ and CEACAMs along with possible mechanisms responsible for pathogenicity of Helicobacter pylori.
    Materials and Methods
    The literature was searched on “PubMed” using different key words including Helicobacter pylori, CEACAM and gastric.
    Results
    HopQ is one of the outer membrane proteins of H. pylori and belongs to the family of adhesin proteins. In contrast to other adhesins, HopQ interacts with host cell surface molecules in a glycan independent manner. Human CEACAMs are the cell surface adhesion molecules mainly present on the epithelial cells, endothelial cells and leukocytes. The overexpression of these molecules may contribute to cancer progression and relapse. Recent studies have shown that HopQ may interact with human CEACAMs, particularly CEACAM1, CEACAM3, CEACAM5 and CEACAM6, but not CEACAM8. HopQ interacts with GFCC’C” interaction surface of IgV domain of N- terminal region of CEACAM1. Moreover, binding of HopQ to CEACAM1 prevent its trans-dimerization and stabilizes it in monomeric form. H. pylori may use these HopQ-CEACAM interactions to transfer its CagA oncoprotein into host gastric epithelial cells, which is followed by its phosphorylation and release of interleukin-8. HopQ-CEACAM interactions may also utilize T4SS, instead of CagA, to activate NF-κB signaling and trigger inflammation.
    Conclusion
    HopQ of H. pylori may interact with CEACAMs of the human gastric cells to induce the development of gastric ulcers and cancers by transferring CagA oncoprotein or inducing activation of T4SS to initiate and maintain inflammatory reactions.
    Keywords: CEACAM, Gastric epithelial cells Helicobacter pylori, Interleukin 8, NF-kB
  • Daniel Hernandez Baltazar *, Rasajna Nadella, Laura Mireya Zavala Flores, Christian de Jesus Rosas Jarquin, Maria de Jesus Rovirosa Hernandez, Arnulfo Villanueva Olivo Pages 716-721
    Objective(s)
    Parkinson’s disease (PD) is characterized by motor and cognitive dysfunctions. The progressive degeneration of dopamine-producing neurons that are present in the substantia nigra pars compacta (SNpc) has been the main focus of study and PD therapies since ages.
    Materials and Methods
    In this manuscript, a systematic revision of experimental and clinical evidence of PD-associated cell process was conducted.
    Results
    Classically, the damage in the dopaminergic neuronal circuits of SNpc is favored by reactive oxidative/nitrosative stress, leading to cell death. Interestingly, the therapy for PD has only focused on avoiding the symptom progression but not in finding a complete reversion of the disease. Recent evidence suggests that the renin-angiotensin system imbalance and neuroinflammation are the main keys in the progression of experimental PD.
    Conclusion
    The progression of neurodegeneration in SNpc is due to the complex interaction of multiple processes. In this review, we analyzed the main contribution of four cellular processes and discussed in the perspective of novel experimental approaches.
    Keywords: Cell death, Dopaminergic neurons, Inflammation, Survival, Therapeutics
  • Sam Zarbakhsh, Manouchehr Safari *, Mohammad Reza Aldaghi, Hamidreza Sameni, Laya Ghahari, Younes Khaleghi Lagmouj, Khojasteh Rahimi Jaberi, Houman Parsaie Pages 722-728
    Objective(s)
    Exercise ameliorates the quality of life and reduces the risk of neurological derangements such as Alzheimer’s (AD) and Parkinson’s disease (PD). Irisin is a product of the physical activity and is a circulating hormone that regulates the energy metabolism in the body. In the nervous system, Irisin influences neurogenesis and neural differentiation in mice. We previously demonstrated that co-treatment of bone marrow stem cells (BMSCs) with a neurotrophic factor reduce Parkinson’s symptoms. Our goal in this project was to evaluate whether Irisin with BMSCs can protect the dopaminergic (DA) neurons in PD.
    Materials and Methods
    35 adult male Wistar rat weighing (200-250 g) were chosen. They were separated into five experimental groups (n=7). To create a Parkinson’s model, intranasal (IN) administration of the MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) was used. The BMSCs (2×106) and Irisin (50 nm/ml) was used for 7 days for treatment after creation of the PD model. After completion of the tests (4 weeks), their brains were used for the TUNEL and immunohistochemical (IHC) assays.
    Results
    One of the important results of this study was that the Irisin induce BMSCs transport into the injured area of the brain. Co-treatment of the Irisin with BMSCs increased tyrosine hydroxylase-positive neurons (TH+) in substantia nigra (SN) and striatum of the PD mice brain. In this group, the number of TUNEL-positive cells significantly decreased. Behavioral symptoms were better in the combination group and Irisin simultaneously.
    Conclusion
    Co- treatment of Irisin with BMSCs protects the DA neurons from degeneration and apoptotic process after MPTP injection.
    Keywords: Irisin, Mesenchymal stem cells, Parkinson’s disease, Substantia nigra, Tunel
  • Yu qi Xia, Jin zhuo Ning, Fan Cheng *, Wei min Yu, Ting Rao, Yuan Ruan, Run Yuan, Yang Du Pages 729-735
    Objective(s)
    The current study was aimed to investigate the effect of morpholin-4-ium 4 methoxyphenyl (morpholino) phosphinodithioate (GYY4137) on ipsilateral epididymis injury in a rat model of experimental varicocele (VC).
    Materials and Methods
    Sixty Wistar rats were randomly assigned to sham, sham plus GYY4137, VC and VC plus GYY4137 groups. Sperm quality parameters, including sperm count, motility and viability were evaluated after 4 weeks. Histological changes were measured by hematoxylin and eosin staining between the groups. The oxidative stress levels were estimated by determining epididymal superoxide dismutase (SOD) and malondialdehyde (MDA). The apoptosis status and the expression of phosphatidylinositol 3′-OH kinase (PI3K)/Akt were analyzed by immunohistochemical analysis, western blot and RT-qPCR.
    Results
    VC resulted in the decrease of sperm parameters, significant histological damage and higher levels of oxidative stress and apoptosis. Compared to the VC group, GYY4137 markedly ameliorated these observed changes. In addition, treatment with GYY4137 obviously reduced the levels of caspase-3 and Bax and increased the levels of the phosphorylation of PI3K p85 and Akt.
    Conclusion
    Our data demonstrated that GYY4137 may alleviate the sperm damage and epididymis injury in experimentally VC-induced rats by activation of the PI3K/Akt pathway.
    Keywords: Apoptosis, Epididymis, GYY4137, Reactive Oxygen Species, Varicocele
  • Tahereh Komeili Movahhed, Azam Moslehi *, Mohammad Golchoob, Shima Ababzadeh Pages 736-744
    Objective(s)
    Non-alcoholic steatohepatitis (NASH) is defined by steatosis and inflammation in the hepatocytes, which can progress to cirrhosis and possibly hepatocellular carcinoma. However, current treatments are not entirely effective. Allantoin is one of the principal compounds in many plants and an imidazoline I receptor agonist as well. Allantoin has positive effects on glucose metabolism and inflammation. In this study, the effects of allantoin on the NASH induced animals and the pathways involved have been evaluated.
    Materials and Methods
    C57/BL6 male mice received saline and allantoin as the control groups. In the next group, NASH was induced by the methionine-choline-deficient diet (MCD) for eight weeks. In the NASH+allantoin group, allantoin was injected four weeks in the mice feeding on an MCD diet. Histopathological evaluations, serum analysis, ELISA assay, and real-time RT-PCR were performed.
    Results
    Allantoin administration decreased serum alanine aminotransferase (ALT), cholesterol, low-density lipoprotein (LDL), hepatic lipid accumulation, and liver tumor necrosis factor (TNFα) level. Also, treatment with allantoin down-regulated the gene expression of glucose-regulated protein 78 (GRP78), activating transcription factor 6 (AFT6), TNFα, sterol regulatory element binding proteins 1c (SREBP1c), fatty acid synthase (FAS), Bax/Bcl2 ratio, caspase3, and P53. On the other hand, peroxisome proliferator-activated receptor alpha (PPARα), apolipoprotein B (Apo B), and acetyl-coenzyme acetyltransferase 1 (ACAT1) gene expression increased after allantoin injection.
    Conclusion
    This study indicated that allantoin could improve animal induced NASH by changes in the expression of endoplasmic reticulum stress-related genes and apoptotic pathways.
    Keywords: Allantoin, Liver, Non-alcoholic steatohepatitis, PPAR?, SREBP1c, Steatosis
  • Zahra Heidari, Abbas Mohammadipour, Parisa Haeri, Alireza Ebrahimzadeh Bideskan * Pages 745-751
    Objective(s)
    Widely used Titanium dioxide nanoparticles (TiO2) enter into the body and cause various organ damages. Therefore, we aimed to study the effect of TiO2 on the substantia nigra of midbrain.
    Materials and Methods
    40 male BALB/c mice were randomly divided into five groups: three groups received TiO2 at doses of 10, 25, and 50 mg/kg, the fourth group received normal saline for 45 days by gavage, and control group (without intervention). Then, Motor tests including pole and hanging tests were done to investigate motor disorders. The animal brain was removed for histological purposes. Accordingly, immunohistochemistry was performed to detect tyrosine hydroxylase positive cells, and then toluidine blue staining was done to identify dark neurons in the substantia nigra. Eventually, the total number of these neurons were counted using stereological methods in different groups.
    Results
    The results showed that the time recorded for mice to turn completely downward on the pole in the TiO2-50 group increased and also the time recorded for animals to hang on the wire in the hanging test significantly decreased (P<0.05) in comparison with other groups. Also, the average number of tyrosine hydroxylase positive neurons in TiO2-25 and TiO2-50 groups significantly decreased as compared to the TiO2-10 and control groups (P<0.05). The total number of dark neurons in the TiO2-25 and TiO2-50 groups was substantially higher than the TiO2-10, control and normal saline groups (P<0.05).
    Conclusion
    Our findings indicated that TiO2, depending on dose, can cause the destruction of dopaminergic neurons and consequently increase the risk of Parkinson’s disease.
    Keywords: Dark neurons, Mice, Substantia nigra, Titanium dioxide nanoparticles, Tyrosine hydroxylase neurons
  • Paria Hashemi, Javad Fahanik Babaei, Somayeh Vazifehkhah, Farnaz Nikbakht * Pages 752-758
    Objective(s)
    Cognitive deficit is a common problem in epilepsy. A major concern emergent from the use of antiepileptic drugs includes their side effects on learning and memory. Herbal medicine is considered a complementary and alternative therapy in epilepsy. Apigenin is a safe flavone with antioxidant properties. However, there is little information about the beneficial effect of apigenin on cognition in epilepsy.
    Materials and Methods
    For evaluating the anticonvulsant effect of apigenin in the kainite temporal epilepsy model, apigenin was orally administered at 50 mg/kg for six days. Reference and working memory were examined via the Morris water maze and Y-maze task spontaneously.
    Results
    Results showed that apigenin had significant anticonvulsant activity (P<0.01) and restored the memory-deficit induced by kainic acid (P<0.05). Furthermore, apigenin significantly increased the number of living neurons in the hilus (P<0.001). Immunohistochemical analysis showed that apigenin reduced the release of cytochrome c (P<0.01), suggesting an inhibitory role in the intrinsic apoptotic pathway.
    Conclusion
    These results suggest that apigenin restores memory impairment via anticonvulsant and neuroprotective activity.
    Keywords: Apigenin, Anticonvulsant, Cognition, Cytochrome c, Neuroprotection, Temporal lobe epilepsy
  • Alexis D?az Garc?a *, Jenny Laura Ruiz Fuentes, Yahima Fri?n Herrera, Arianna Yglesias Rivera, Yanelis Riquenez Garlobo, Hermis Rodr?guez S?nchez, Juan C Rodr?guez Aurrecochea, Ledys X L?pez Fuentes Pages 759-765
    Objective(s)
    In Cuba the endemic scorpion species Rhopalurus junceus has been used in traditional medicine for cancer treatment and related diseases. However there is no scientific evidence about its therapeutic potential for cancer treatment. The aim of the study was to determine the antitumor effect of scorpion venom against a murine mammary adenocarcinoma F3II.
    Materials and Methods
    The cytotoxic activity was determined by MTT assay with venom concentrations ranging from 0.1–1 mg/ml. Apoptosis was determined by RT-PCR and flow cytometry. Toxic effect in healthy animals and tumor growth kinetics in F3II bearing-mice were evaluated by using scorpion venom doses (0.2; 0.8; 3.2 mg/kg) after one and ten injections respectively by the intraperitoneal route.
    Results
    Scorpion venom induced a significant cytotoxic effect (P<0.05) in F3II cells in a concentration-dependent manner. The cell death event involves the apoptotic pathway due to up-regulation of pro-apoptotic genes (p53, bax), down-regulation of antiapoptotic gene (bcl-2), and 33% of Annexin V+/PI- cells at early apoptosis and 10.21% of Annexin V+/PI+ cells at late apoptosis. Scorpion venom induced significant inhibition of tumor progression (P<0.05) in F3II bearing-mice in a dose-dependent manner. The antitumor effect was confirmed due to dose-dependent reduction of Ki-67 and CD31 proteins present in tumor tissue.
    Conclusion
    Evidence indicates that scorpion venom can be an attractive natural product for deep investigation and developing a novel therapeutic agent for breast cancer treatment.
    Keywords: Antitumor, Apoptosis, Cytotoxicity, Murine mammary adenocarcinoma, Scorpion venom
  • Nafiseh Pakravan *, Ameneh Ghaffarinia, Shahram Parvaneh, Cyrus Jalili, Farhad Riazirad Pages 766-773
    Objective(s)
    Multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE), are regarded as autoimmune diseases of the central nervous system (CNS).  The CNS, testes, and eyes are immune privileged sites.  It was initially presumed that ocular involvement in EAE and infertility in MS are neural-mediated.  However, inflammatory molecules have been detected in the eyes of animals affected by EAE.  It prompted us to investigate if the testes may also be targeted by immune response during EAE.
    Materials and Methods
    kinetics of T cell response was investigated in the CNS and testes in EAE at different clinical scores.  IFN-γ, IL-4, IL-17, and FoxP3 mRNA expressions were considered as representatives of Th1, Th2, Th17, and Treg, respectively.
    Results
    In CNS, IL-17 and IFN-γ were initially up-regulated and attenuated at the late phase of the disease.  IL-4 and FoxP3 were markedly down-regulated, but IL-4 was then up-regulated at the late phase of the disease.  In the testes, IFN-γ and IL-17 were diminished but increased at the late phase of the disease.  FoxP3 was gradually increased from the initial step to the peak of the disease.  IL-17/ IFN-γ showed a similar pattern between the CNS and testes.  However, FoxP3 and IL-4 expression appeared to have different timing patterns in the CNS and testes.
    Conclusion
    Given the permeability in blood-retina/brain/CSF barrier by complete Freund’s adjuvant, the pattern of T cells may be changed in the testes during EAE as a consequence of the blood-testis barrier permeability. More research is required to explore the connection between immune privileged organs.
    Keywords: Barrier, CFA, CNS, EAE, Immune privilege, T cell, Testes
  • Shahrzad Zamani, Ahmad Emami, Mehrdad Iranshahi, Shahin Zamani Taghizadeh Rabe, Mahmoud Mahmoudi * Pages 774-780
    Objective(s)
    Artemisia species are important medicinal plants throughout the world. Some species are traditionally used for their anti-inflammatory effect. The present study was designed to isolate sesquiterpene fractions from several Artemisia species and evaluate their anti-inflammatory activities on key mediators and signaling molecules involved in regulation of inflammation.
    Materials and Methods
    Sesquiterpene fractions were prepared from several Artemisia species using the Herz-Högenauer technique. Lipopolysaccharide (LPS)-stimulated J774A.1 macrophages were exposed to isolated fractions. Their possible cytotoxic effect was examined using MTT assay. In addition, nitric oxide (NO) release was measured using Griess method and prostaglandin E2 (PGE2) level was determined by enzyme-linked immunosorbent assay (ELISA). Moreover, protein expression of pro-inflammatory enzymes, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) were investigated using Western blot analysis.
    Results
    Nitric oxide level produced by LPS-primed macrophages was significantly decreased with all prepared fractions in a dose-dependent manner. Saturated sesquiterpene lactones-rich species (Artemisia kopetdaghensis, Artemisia santolina, Artemisia sieberi) showed the highest suppressive activity on NO and PGE2 production via suppression of iNOS and COX-2 expression. Fractions bearing unusual (Artemisia fragrans and Artemisia absinthium) and unsaturated sesquiterpene lactones (Artemisia ciniformis) possess less modulatory effect on PGE2 production and COX-2 expression.
    Conclusion
    It can be concluded that some of the medicinally beneficial effects attributed to Artemisia plants may be associated with the inhibition of pro-inflammatory signaling pathways. However, these effects could be dependent on the type of their sesquiterpene content. These findings also introduce new Artemis species cultivated in Iran as a useful anti-inflammatory agents.
    Keywords: Artemisia, Asteraceae, Sesquiterpene lactone fraction, Macrophage, Inflammation
  • Le Hien, Phi Trang, Pham Phuong, Pham Tam, Nguyen Xuan * Pages 781-788
    Objective(s)
    Copper (Cu) is an essential dietary supplement in animal feeds, which plays an important role in maintaining the balance of all living organisms. Copper nanoparticles (nCu) participate in catalysing activities of multiple antioxidant/defensive enzymes and exerts pro-inflammatory and pro-apoptotic effects on systemic organs and tissues. The present study explored whether nCu affects maize growth and yield and grain mineral nutrients as well as physiological functions in mice.
    Materials and Methods
    Maize seeds were treated with nCu (20 mg/kg and 1000 mg/kg dry weight (DW)) and their grain productions were used for mouse feed. For testing of autoimmune response, mice were treated with nCu at concentration of 2 mg/l and 1000 mg/l and ultimately serum biochemical indicators, numbers and activation of immune cells infiltrated in mouse spleens were examined.
    Results
    Treatment of maize seeds with nCu at dose of 20 mg/kg DW, but not 1000 mg/kg DW enhanced germination rate, plant growth and grain yield as well as grain mineral nutrients as compared to control group. Importantly, administration of mice with 1000 mg/l nCu resulted in their morphological change due to excessive accumulation of nCu in liver and blood, leading to inflammatory responses involved in upregulated expression of serum biochemical indicators of liver and kidney as well as increased infiltration and activation of splenic immune cells.
    Conclusion
    nCu concentration at 20 mg/kg DW facilitated the morphological and functional development of maize plants, whose production was safe to feed mice.
    Keywords: ALT, AST, Copper, Leukocytes, Maize
  • Vahid Akbari, Kordkheyli, Soheil Azizi, Abbas Khonakdar Tarsi * Pages 789-796
    Objective(s)
    Liver ischemia-reperfusion injuries (I/RI) are typically the main causes of liver dysfunction after various types of liver surgery especially liver transplantation. Radical components are the major causes of such direct injuries. We aimed to determine the beneficial effects of silibinin, a potent radical scavenger on liver I/RI.
    Materials and Methods
    Thirty-two rats were divided into 4 groups. Group I: VEHICLE, the rats underwent laparotomy and received DMSO, group II: SILI, laparotomy was done and silibinin was administered. Group III: I/R, the rats received DMSO and were subjected to a liver I/R procedure and group IV: I/R+SILI, the animals underwent the I/R procedure and received silibinin. After 1 hr of ischemia followed by 3 hr reperfusion, blood was collected to evaluate the serum marker of liver injuries. Hepatic tissue was harvested to investigate glycogen content, histological changes, and vasoregulatory gene expression.
    Results
    Results showed that serum AST, ALT, LDH, GGT, ALP, and hyaluronic acid (HA) increased significantly in I/R group compared with the VEHICLE group. Silibinin reduced this elevation except for GGT. Silibinin inhibited hepatocyte vacuolization and degeneration, endothelium damages, sinusoidal congestion and inflammation, and glycogen depletion during I/R. ET-1 mRNA was overproduced in the I/R group compared with the VEHICLE group which was decreased by silibinin. KLF2 and eNOS expression was reduced during I/R compared with the VEHICLE group. Silibinin elevated KLF2 expression but had no meaningful effect on eNOS expression.
    Conclusion
    Silibinin protected the liver from I/RI. Silibinin could improve liver circulation by preventing sinusoidal congestion, inflammation, and perhaps modification of the vasoregulatory gene expression.
    Keywords: eNOS, ET-1, KLF2, Liver Ischemia, reperfusion, Silibinin
  • Jia wen Dang, Xiao ping Lei, Qing ping Li, Wen bin Dong Pages 797-805
    Objective(s)
    Asiaticoside (AS) displays anti-inflammation, and anti-apoptosis effect, but the role of AS in hyperoxia-induced lung injury (HILI) treatment is undefined. Therefore, the aim of this study was to investigate the effects of AS on HILI on premature rats and alveolar type II (AEC II) cells.
    Materials and Methods
    Sprague-Dawley premature rats (n=25/group) were exposed to 80% O2 with or without AS. Then, we detected 80% O2-induced lung injury and survival rate of premature rat. We tested the concentration of malondialdehyde (MDA), myeloperoxidase (MPO), total antioxidant capacity (TAOC), tumor necrosis factor α (TNF-α), interleukin 6 (IL-6), and interleukin 1β (IL-1β) in premature rats’ blood. Then, the AEC II cell apoptosis was observed by Hoechst 33258 staining and flow cytometry. Simultaneously, nuclear factor (erythroid-derived 2)-like 2 (Nrf2) signaling pathway was measured by Western blot.
    Results
    Our results found that AS-treated group rats had significantly higher survival rates than 80% O2 group at day 14 (P<0.05). AS protected HILI, decreased the MPO and MDA concentration, and reversed TAOC level (P<0.05). AS also downregulated the levels of TNF-α, IL-1β, and IL-6 in the premature rat’s blood (P<0.01). Moreover, AS markedly attenuated AEC II cell apoptosis and increased Nrf2 and Heme oxygenase 1 (HO-1) expression in the nucleus (P<0.05).
    Conclusion
    AS showed protective effects on premature rats of HILI in vitro and in vivo. AS can potentially be developed as a novel agent for the treatment of HILI diseases.
    Keywords: Apoptosis, Asiaticoside, Hyperoxia, Inflammation, Lung injury, Premature
  • Hossein Sharifi, Gholamreza Pouladfar, Mohammad Reza Shakibaie, Bahman Pourabbas, Jalal Mardaneh, Shahla Mansouri * Pages 806-812
    Objective(s)
    Pseudomonas aeruginosa is one of the most important nosocomial pathogens causing a high rate of mortality among hospitalized patients. Herein, we report the prevalence of antibiotic resistance genes, class 1 integrons, major virulence genes and clonal relationship among multidrug- resistant (MDR) P. aeruginosa, isolated from four referral hospitals in the southeast of Iran.
    Materials and Methods
    In this study, 208 isolates of P. aeruginosa were collected from four referral hospitals in southeast of Iran. Disk diffusion method was used to determine susceptibility to 13 antibacterial agents. AmpC was detected by phenotypic method and β-lactamase genes, virulence genes and class 1 integrons were detected by PCR. Clonal relationship of the isolates was determined by RAPD-PCR.
    Results
    All the isolates were susceptible to polymyxin-B and colistin. Overall, 40.4% of the isolates were MDR, among which resistance to third generation cephalosporins, aminoglycosides, and carbapenems was 47.5%, 32.3% and 40%, respectively. None of the isolates was positive for blaNDM-1 genes, while 84.5% and 4.8% were positive for the blaIMP-1 and blaVIM, metallo-β-lactamase genes, respectively. Incidence of class 1 integrons was 95% and AmpC was detected in 33% of the isolates. Prevalence of exoA, exoS, exoU, pilB and nan1 were 98.8%, 44%, 26%, 8.3% and 33.3%, respectively. RAPD profiles identified four large clusters consisting of 77 isolates, and two small clusters and three singletons.
    Conclusion
    The rate of MDR P. aeruginosa isolates was high in different hospitals in this region. High genetic similarity among MDR isolates suggests cross-acquisition of infection in the region.
    Keywords: Antibiotic resistance, Beta-lactamases, Class 1 integrons, Pseudomonas aeruginosa, RAPD-PCR, virulence factors
  • Hamid Heidari, Hadi Sedigh Ebrahim Saraie, Ali Amanati, Mohammad Motamedifar, Nahal Hadi, Abdollah Bazargani * Pages 813-819
    Objective(s)
    Clostridioides (Clostridium) difficile infection as a healthcare-associated infection can cause life-threatening infectious diarrhea in hospitalized patients. The aim of this study was to investigate the toxin profiles and antimicrobial resistance patterns of C. difficile isolates obtained from hospitalized patients in Shiraz, Iran.
    Materials and Methods
    This study was performed on 45 toxigenic C. difficile isolates. Determination of toxin profiles was done using polymerase chain reaction method. Antimicrobial susceptibility to vancomycin, metronidazole, clindamycin, tetracycline, moxifloxacin, and chloramphenicol was determined by the agar dilution method. The genes encoding antibiotic resistance were detected by the standard procedures.
    Results
    The most frequent toxin profile was tcdA+, tcdB+, cdtAˉ, cdtBˉ (82.2%), and only one isolate harboured all toxin associated genes (tcdA+, tcdB+, cdtA+, cdtB+) (2.2%). The genes encoding CDT (binary toxin) were also found in six (13.3%) isolates. Resistance to tetracycline, clindamycin and moxifloxacin was observed in 66.7%, 60% and 42.2% of the isolates, respectively. None of the strains showed resistance to other antibiotics. The distribution of the ermB gene (the gene encoding resistance to clindamycin) was 57.8% and the tetM and tetW genes (the genes encoding resistance to tetracycline) were found in 62.2% and 13.3% of the isolates, respectively. The substitutions Thr82 to Ile in GyrA and Asp426 to Asn in GyrB were seen in moxifloxacin resistant isolates.
    Conclusion
    Our data contributes to the present understanding of virulence and resistance traits amongst the isolates. Infection control strategies should be implemented carefully in order to curb the dissemination of C. difficile strains in hospital.
    Keywords: Clostridioides (Clostridium) difficile, C. difficile infection, Toxins, CDT, Antibiotic resistance
  • Sapna Aggarwal, Jasleen Kaur Virdi, Nirmal Singh, Amteshwar Singh Jaggi * Pages 820-826
    Objective(s)
    This study explored the inter-relationship among nitric oxide, opioids, and KATP channels in the signaling pathway underlying remote ischemic preconditioning (RIPC) conferred cardioprotection.
    Materials and Methods
    Blood pressure cuff was placed around the hind limb of the animal and RIPC was performed by 4 cycles of inflation (5 min) followed by deflation (5 min). An ex vivo Langendorff’s isolated rat heart model was used to induce ischemia (of 30 min duration)-reperfusion (of 120 min duration) injury.
    Results
    RIPC significantly decreased ischemia-reperfusion associated injury assessed by decrease in myocardial infarct, LDH and CK release, improvement in postischemic left ventricular function, LVDP, dp/dtmax, and dp/dtmin. Pretreatment with L-NAME and naloxone abolished RIPC-induced cardioprotection. Moreover, preconditioning with sodium nitroprusside (SNP) and morphine produced a cardioprotective effect in a similar manner to RIPC. L-NAME, but not naloxone, attenuated RIPC and SNP preconditioning-induced increase in serum nitrite levels. Morphine preconditioning did not increase the NO levels, probably suggesting that opioids may be the downstream mediators of NO. Furthermore, glibenclamide and naloxone blocked cardioprotection conferred by morphine and SNP, respectively.
    Conclusion
    It may be proposed that the actions of NO, opioids, and KATP channels are interlinked. It is possible to suggest that RIPC may induce the release of NO from endothelium, which may trigger the synthesis of endogenous opioids, which in turn may activate heart localized KATP channels to induce cardioprotection.
    Keywords: Cardioprotection, KATP channels, Nitric oxide, Opioids, Remote ischemic preconditioning
  • Mubashar Aziz *, Rafael Garduno, Zulfiqar Mirani, Rakhshanda Baqai, Ahsan Sheikh, Humera Nazir, Mazhar Ayyaz, Shahana Kazmi Pages 827-832
    Objective(s)
    Diabetic foot infection is one of the major complications of diabetes leading to lower limb amputations. Isolation and identification of bacteria causing diabetic foot infection, determination of antibiotic resistance, antimicrobial potential of protamine by electron microscopy and SDS-PAGE analysis, arethe aims of this study.
    Materials and Methods
    285 pus samples from diabetic foot infection patients were collected from different hospitals of Karachi and Capital Health Hospital, Halifax, Canada. Clinical history of each patient was recorded. Bacterial isolates were cultured on appropriate media; identification was done by morphology, cultural and biochemical tests. Effect of protamine against multi drug resistant strains of Pseudomona aeruginosa was checked by minimum inhibitory concentration in 96 well micro-titer plates. The isolates were grown in bactericidal concentration of protamine on plates to isolate mutants. Effect of protamine on protein expression was checked by SDS- PAGE and ultra-structural morphological changes by transmission electron microscopy.
    Results
    Results indicated prevalence of foot infection as 92% in diabetic patients. Major bacterial isolates were Staphylococcus aureus 65 (23%), P. aeruginosa 80 (28.1%), Klebsiella spp. 37 (13%), Proteus mirabilis 79 (27.7%), and Escherichia coli 24 (12%). These isolates were highly resistant to different antibiotics. MIC value of protamine was 500 µg/ml against P. aeruginosa. SDS-PAGE analysis revealed that protamine can suppress expression of various virulence proteins and electron micrographs indicated condensation of cytoplasm and accumulation of protamine in cytoplasm without damaging the cell membrane.
    Conclusion
    P. aeruginosa and S. aureus were the major isolates expressing multi-drug resistance and protamine sulfate represented good antimicrobial potential.
    Keywords: Diabetic foot, Pseudomonas aeruginosa, Protamine, Transmission electron microscopy, Polyacrylamide Gel