Beneficial effects of thyme (Thymus vulgaris) extract on oxytetracycline‐induced stress response,immunosuppression, oxidative stress and enzymatic changes in rainbow trout (Oncorhynchus mykiss)

The aim of the present study was to investigate the effects of thyme extract (TE) and oxytetracycline (OTC) on rainbow trout (Oncorhynchus mykiss) stress response, immune parameters, oxidative stress and enzymatic changes. The fish were assigned into eight treatments receiving diets with OTC (0 and 2.5 g/kg) and TE (0, 5, 10 and 20 g/kg) for 2 weeks. Thereafter, serum characteristics and gut oxidative status were evaluated. OTC significantly increased serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities, and cortisol and glucose levels; however, TE significantly suppressed these changes. OTC significantly decreased, but TE significantly increased gut catalase (CAT) and glutathione peroxidase (GPx) activities. OTC significantly decreased gut superoxide dismutase (SOD) and increased gut glutathione‐s‐transferase (GST) activities, malondialdehyde (MDA) content and blood monocyte percentage; TE significantly mitigated these changes. TE significantly increased serum total protein, total Ig, lysozyme and ACH50, and blood WBC; however, OTC significantly decreased serum lysozyme and ACH50 activities and blood WBC and neutrophil percentage. In conclusion, OTC administration causes immunosuppression, which might be related to deterioration of fish health. TE augments trout innate immune and antioxidant status and is capable to counteract OTC‐induced health and immune deterioration.     

Effects of fasting on metabolic and immunological responses of common carp (Cyprinus carpio) to a further acute stress

Common carp were fasted for 0, 3 and 14 days prior to exposure to a 2‐hr crowding stress. Serum cortisol, glucose, lactate, _{T4, T3}, serum alternative complement (ACH50), lysozyme, total immunoglobulin (Ig) and blood WBC were determined before and 0, 6 and 24 hr after the crowding stress. Three days of fasting led to a significant decrease in serum levels of lactate and thyroid hormones. Fourteen days of fasting led to initiation of physiological process to maintain serum glucose by increase in serum cortisol level and lactate utilization. These fish had lower levels of thyroid hormones suggesting suppression of basal metabolism. The fish also had lower WBC and serum lysozyme and total Ig levels indicating immunosuppression. After the crowding stress, the fish fasted for 3 days had significantly lower lactate, thyroid hormones and total Ig levels. The fish fasted for 14 days had higher cortisol but lower glucose and thyroid hormones levels suggesting impairment in metabolic responses to the crowding stress. Immunological and health indicators including WBC, and ACH50, lysozyme and total Ig of these fish were significantly lower than the other groups after the crowding stress. Overall, the results show that a 14‐day fasting leads to stress responses, reduction in metabolism and immunosuppression. Moreover, 14 days of fasting lead to greater cortisol response to a further crowding stress, which induces marked immunosuppression and fallen welfare.     

A Novel Splice Site Variant in the LDLRAP1 Gene Causes Familial Hypercholesterolemia

Background:FH, a hereditary disorder, is caused by pathogenic variants in the LDLR, APOB, and PCSK9 genes. This study has assessed genetic variants in a family, clinically diagnosed with FH. Methods:A family was recruited from MASHAD study in Iran with possible FH based on the Simon Broom criteria. The DNA sample of an affected individual (proband) was analyzed using WES, followed by bioinformatics and segregation analyses. Results:A novel splice site variant (c.345-2A>G) was detected in the LDLRAP1 gene, which was segregated in all affected family members. Moreover, HMGCR rs3846662 g.23092A>G was found to be homozygous (G/G) in the proband, probably leading to reduced response to simvastatin and pravastatin. Conclusion:LDLRAP1 c.345-2A>G could alter the PTB, which acts as an important part of biological pathways related to lipid metabolism. Key Words: Genetic research, LDLRAP1, Hypercholesterolemia, Hydroxymethylglutaryl-CoA Reductase Inhibitors     

Mitochondrial DNA Copy Number Variations and Serum Pepsinogen Levels for Risk Assessment in Gastric Cancer

Background:Variations in mtDNA-CN of PBLs, as a potential biomarker for GC screening has currently been subject to controversy. Herein, we have assessed its efficiency in GC screening, in parallel and in combination with sPG I/II ratio, as an established indicator of gastric atrophy. Methods:The study population included GC (n = 53) and non-GC (n = 207) dyspeptic patients. The non-GC group was histologically categorized into CG (n = 104) and NM (n = 103) subgroups. The MtDNA-CN of PBLs was measured by quantitative real-time PCR. The sPG I and II levels and anti-H. pylori serum IgG were measured by ELISA. Results:The mtDNA-CN was found significantly higher in GC vs. non-GC (OR = 3.0; 95% CI = 1.4, 6.4) subjects. Conversely, GC patients had significantly lower sPG I/II ratio than the non-GC (OR = 3.2; CI = 1.4, 7.2) subjects. The combination of these two biomarkers yielded a dramatic amplification of the odds of GC risk in double-positive (high mtDNA-CN-low sPGI/II) subjects, in reference to double-negatives (low mtDNA-CN-high sPGI/II), when assessed against non-GC (OR = 27.1; CI = 5.0, 147.3), CG (OR = 13.1; CI = 2.4, 72.6), or NM (OR = 49.5; CI = 7.9, 311.6) groups. Conclusion:The combination of these two biomarkers, namely mtDNA-CN in PBLs and serum PG I/II ratio, drastically enhanced the efficiency of GC risk assessment, which calls for further validations. Key Words: Biomarkers, DNA copy number variation, Mitochondrial DNA, Stomach neoplasms     

Effect of Transient Inactivation of Ventral Tegmental Area on the Expression and Acquisition of Nicotine-Induced Conditioned Place Preference in Rats

Background:

Nicotine can activate dopaminergic neurons within the ventral tegmental area (VTA). However, there is no evidence about complete inhibition of VTA on nicotine reinforcement.

Methods:

in the present study, we used conditioned-place preference (CPP) method to study the effect of transient inhibition of left and/or right side of the VTA by lidocaine on nicotine reward properties. Male Wistar rats seven days after recovery from surgery and cannulation were conditioned to nicotine (1.5 mg/kg) in an unbiased designed CPP apparatus. Five min before each nicotine injection in conditioning phase, lidocaine (2%) was administered either uni- or bi-laterally into the VTA (0.5µl/rat).

Results:

results revealed that lidocaine administration into the left but not right side of the VTA reduced nicotine CPP significantly. The reduction was potentiated when lidocaine injected in to both sides of the VTA. In addition, the number of compartment crossing was reduced when lidocaine injected in both side of VTA as well as left side. On the other hand, rearing was reduced when lidocaine injected to the right but not left side of VTA. At last, sniffing was reduced only in the group in which received lidocaine in both side of VTA. Sniffing and rearing increased in the group in which received lidocaine in right side.

Conclusion:

It is concluded that the right and left side of VTA play different role in nicotine-induced activity and reward.     

Prevalence of Class 1 Integrons and Extended Spectrum Beta Lactamases among Multi-Drug Resistant Escherichia coli Isolates from North of Iran

Background:

Extended spectrum beta lactamases (ESBLs) are an important cause of transferable multidrug resistance (MDR) in gram-negative bacteria. The most described ESBL genes are generally found within integron-like structures as mobile genetic elements. The aim of this study was to identify the accompanying of class 1 integrons and ESBLs in the MDR E. coli isolates.

Methods:

Susceptibility to antimicrobial agents was determined for 33 E. coli strains by the disk diffusion method. Double-disk synergy test was applied for screening ESBL. To identify the strains carrying integrons, the conserved regions of integron-encoded integrase gene intI1 were amplified. For detection of gene cassettes, 5′CS and 3′CS primers were used.

Results:

All E. coli isolates were identified as multi-drug resistant. More than 50% of the isolates were resistant to tetracycline, cephalothin, cefuroxime, amoxicillin-clavulanic acid, and third generation cephalosporines. Nearly all of the isolates displayed sensitivity to piperacillin. There was a significant correlation between production of ESBL and resistance to all antibiotics except for ciprofloxacin and piperacillin (P < 0.01). Thirty two MDR strains (97%) included class 1 integron, and some isolates that included integrons were similar in the size of gene cassettes. The isolates were different in the resistance profiles; however, some others had similar resistance profiles. Of eight ESBL positive isolates, seven (87.5%) carried class 1 integrons.

Conclusion:

Class 1 integrons were frequent in MDR and also ESBL-producing E. coli isolates. High prevalence of class 1 integrons confirms that integron-mediated antimicrobial gene cassettes are important in E. coli resistance profile. Key Words: Antibiotic, Integrons, Escherichia coli     

A PCR-based assay for differentiating A- and A*-type strains of Xanthomonas citri subsp. citri, the causal agent of Asiatic citrus canker

By applying A- and A*-type strains of Xanthomonas citri subsp. citri (Xcc) in a repetitive sequence-based polymerase chain reaction (rep-PCR), two DNA amplicons, one unique to each strain, were evaluated as a probe against the DNA of Xcc strains. Two pairs of primers derived from these amplicons were tested in a PCR analysis. The results confirmed that primers Ms⁺/Ms^? are useful for differentiating A-type from A*-type strains of Xcc. Also, a multiplex PCR with both set of primers can be used to distinguish three groups in Xcc populations: A-type strains and two subgroups of A* strains including Iranian and Thai A* strains.     

Serum biochemical and non-specific immune responses of rainbow trout (<Emphasis Type="Italic">Oncorhynchus mykiss</Emphasis>) to dietary nucleotide and chronic stress

The aim of the present study was to investigate whether supplementary nucleotide “Optimun” mitigates the adverse effects of chronic overcrowding in Oncorhynchus mykiss. Two experimental diets [control and nucleotide-supplemented (0.2 %)] and two rearing densities (10 and 30 kg m^?3) were combined to have four experimental treatments. The fish were reared for 45 days under different densities using different diets. At the end of the trial, FCR of the fish in higher density was significantly higher than those of the lower density. Nucleotide had no significant effects on growth performance and survival rate. Supplemented nucleotide significantly increased blood hematocrit, whereas it decreased serum total protein, total immunoglobulin (Ig) and creatinine. Overcrowding significantly increased serum glucose and total protein level and decreased serum lysozyme activity, but supplemented nucleotide produced no improvement in these items. No significant effect of overcrowding and dietary nucleotide was observed on serum cortisol. Supplemented nucleotide significantly increased serum urea under low stocking density. Overall, the results showed that 0.2 % “Optimun” had no positive effects on rainbow trout and also caused some immunological and metabolic problems. These findings are not in accordance with those obtained in the same species, with same nucleotide source and level, but acute stress; thus, further studies are encouraged on this topic.     

Effect of β-aminobutyric acid on resistance of tomato against Pectobacterium carotovorum subsp. carotovorum

Journal of Plant Diseases and Protection - Stem rot of tomato caused by Pectobacterium carotovorum subsp. carotovorum (Pcc) results in economic yield loss worldwide. Previous studies have...     

Investigation on the Biodegradability and Antibacterial Properties of Nanohybrid Suture Based on Silver Incorporated PGA-PLGA Nanofibers

Polyglycolic acid-poly lactic glycolic acid (PGA-PLGA) electrospun nanofibers containing silver nanoparticles have been produced and twisted into the nanofibrous yarn. The morphology of nanofibers and produced yarns, as well as the mechanical properties of the yarns, were investigated. Furthermore, in vitro antibacterial properties and in vitro degradation behavior of yarns containing various silver nanoparticles were studied. SEM images confirmed that the addition of the silver nanoparticles into the polymer solution increases the fiber diameters. The result of the mechanical test of the yarns alone and used in two different forms of the knots was measured and results showed that the strength of the yarns without the knot was significantly more than that of others. The biodegradability test showed that the mechanical properties and the weight of the yarns were quickly reduced after subjecting to in vitro condition. The result of the antibacterial test indicated that the nanofiber yarns containing %3 silver nanoparticles were the most appropriate sample with a considerably antibacterial activity against both gram-positive bacterium Staphylococcus aureus and gram-negative bacterium Escherichia Coli with inhibition zones of 8.1 and 9.5 mm, respectively; which demonstrated that silver nanoparticles retained their effectiveness after the electrospinning process. Therefore the nanofibrous yarns containing silver nanoparticles could be successfully produced by the electrospinning process with the proper antibacterial property as a candidate for the surgical sutures.