The effects of short-term uniaxial strain on the mechanical properties of mesenchymal stem cells upon TGF-β<Subscript>1</Subscript> stimulation

Cellular mechanical characteristics represent cell ability to produce tissue-specific metabolites. Therefore, to achieve effective cell therapy, a better understanding of the effects of chemo-mechanical stimuli on the mechanical properties of in vitro-treated cells is essential. Herein, we investigated the effects of uniaxial strain on the mechanical properties of mesenchymal stem cells (MSCs) upon transforming growth factor beta 1 (TGF-β₁) stimulation. The MSCs were categorized into control and test groups. In one test group, the MSCs were treated by TGF-β₁ for 6 d, and in the other, they were additionally subjected to 1-d uniaxial strain on day 2. The cell mechanical properties and smooth muscle (SM) gene expression were assessed on days 2, 4, and 6. During the entire experiment, the MSCs treated by TGF-β₁ ± uniaxial strain were induced to differentiate into SM-like cells by significantly upregulation of α-actin, SM22α, and h1-calponin in respect to the control samples. When the MSCs were treated with TGF-β₁ alone, their stiffness and viscosity decreased significantly on day 2 and then increased by increase in culture time. When the cells were subjected to 1-d uniaxial strain upon TGF-β₁ stimulation, their stiffness and viscosity significantly increased on days 2 and 4 and then decreased on day 6 to a level comparable to that of TGF-β₁ group. Different paths were noticeable among the treated samples to reach nearly similar states on day 6. It seems that uniaxial strain activates mechanobiological cascades by which cellular mechanical behavior can be regulated after its removal. However, these effects are transient and would diminish over time. The findings may be helpful in the chemo-mechanical regulation of MSCs.     

Establishment and characterization of Caspian horse fibroblast cell bank in Iran

Caspian horse, a rare horse breed found in 1965 by Louise Firouz in northern Iran, is a small horse which is reported to be in danger of extinction in its original homeland. There seems to be a great need to prevent extinction of this valuable horse. In this study, 51 fibroblast cell lines from Caspian horse ear marginal tissue were successfully established by sampling 60 horses using primary explant technique. Cells were authenticated and growth curve was plotted. According to results obtained, population doubling time (PDT) was calculated 23 ± 0.5 h for all cell lines. Multiplex polymerase chain reaction (multiplex PCR) revealed that cell lines had no cross-contamination with other species. Bacteria, fungi, and mycoplasma contamination were checked using standard methods such as PCR, direct culture, and Hoechst staining. In addition to providing a valuable source for genomic, postgenomic, and somatic cloning researches, the established cell lines would preserve Caspian horse genetic resources. It will also create an accessible database for researchers.     

Pulmonary nocardiosis associated with cerebral abscess successfully treated by co-trimoxazole: a case report

Nocardiosis is an acute or chronic infectious disease caused by the soil-borne filamentous bacteria belonging to the genus Nocardia. The organisms opportunistically infect both immunocompromised and immunocompetent individuals. The lungs are the primary site of infection and brain abscess is, by far, the most common complication following nocardial metastasis from pulmonary lesions. Although surgical intervention must always be considered in the treatment of nocardial brain abscess, it can obviously be cured by antibiotic therapy alone. This report describes a case infected by Nocardia cyriacigeorgica. Identification of the infectious agent was achieved by conventional and semi-nested PCR techniques. A 55-year-old woman with fever was referred to the infect disclinic of Imam Khomeini hospital in Tehran and was hospitalized after clinical assessment. She was a kidney transplant recipient for 4 years and was taking immunosuppressive treatment including azathioprine and methylprednisolone. Follow-up of the patient by CT scan revealed pulmonary infection and cerebral lesions. Specimens of the brain lesions contained filamentous bacteria. The patient received a combination of co-trimoxazole and ceftriaxone and brain abscesses as well as lung inflammation disappeared gradually during the course of antibiotic therapy within 3 months. The patient was discharged from the hospital after 2 months of therapy.     

Diagnosis of <Emphasis Type="Italic">Chenopodium album</Emphasis> allergy with a cocktail of recombinant allergens as a tool for component-resolved diagnosis

Chenopodium album pollen is one of the main sources of pollen allergy in desert and semi-desert areas and contains three identified allergens, so the aim of this study is comparison of the diagnostic potential of C. album recombinant allergens in an allergenic cocktail and C. album pollen extract. Diagnostic potential of the allergenic cocktail was investigated in 32 individuals using skin prick test and obtained results were compared with the acquired results from C. album pollen extract. Specific IgE reactivity against the pollen extract and allergenic cocktail was determined by ELISA and western blotting tests. Inhibition assays were performed for the allergenic cocktail characterization. The exact sensitization profile of all patients was identified which showed that 72, 81 and 46% of allergic patients had IgE reactivity to rChe a 1, rChe a 2 and rChe a 3, respectively. Almost all of C. album allergic patients (30/32) had specific IgE against the allergenic cocktail. In addition, there was a high correlation between IgE levels against the allergenic cocktail and IgE levels against the pollen extract. The allergenic cocktail was able to completely inhibit IgE binding to natural Che a 1, Che a 2 and Che a 3 in C. album extract. In addition, positive skin test reactions were seen in allergic patients that tested by the allergenic cocktail. The reliable results obtained from this study confirmed that the allergenic cocktail with high diagnostic potential could be replaced with natural C. album allergen extracts in skin prick test and serologic tests.     

Di-isodityrosine is the intermolecular cross-link of isodityrosine-rich extensin analogs cross-linked in vitro

Extensins are cell wall hydroxyproline-rich glycoproteins that form covalent networks putatively involving tyrosyl and lysyl residues in cross-links catalyzed by one or more extensin peroxidases. The precise cross-links remain to be chemically identified both as network components in muro and as enzymic products generated in vitro with native extensin monomers as substrates. However, some extensin monomers contain variations within their putative cross-linking motifs that complicate cross-link identification. Other simpler extensins are recalcitrant to isolation including the ubiquitous P3-type extensin whose major repetitive motif, Hyp)(4)-Ser-Hyp-Ser-(Hyp)(4)-Tyr-Tyr-Tyr-Lys, is of particular interest, not least because its Tyr-Tyr-Tyr intramolecular isodityrosine cross-link motifs are also putative candidates for further intermolecular cross-linking to form di-isodityrosine. Therefore, we designed a set of extensin analogs encoding tandem repeats of the P3 motif, including Tyr --> Phe and Lys --> Leu variations. Expression of these P3 analogs in Nicotiana tabacum cells yielded glycoproteins with virtually all Pro residues hydroxylated and subsequently arabinosylated and with likely galactosylated Ser residues. This was consistent with earlier analyses of P3 glycopeptides isolated from cell wall digests and the predictions of the Hyp contiguity hypothesis. The tyrosine-rich P3 analogs also contained isodityrosine, formed in vivo. Significantly, these isodityrosine-containing analogs were further cross-linked in vitro by an extensin peroxidase to form the tetra-tyrosine intermolecular cross-link amino acid di-isodityrosine. This is the first identification of an inter-molecular cross-link amino acid in an extensin module and corroborates earlier suggestions that di-isodityrosine represents one mechanism for cross-linking extensins in muro.     

Bioactive glass ceramic nanoparticles-coated poly(l-lactic acid) scaffold improved osteogenic differentiation of adipose stem cells in equine

Horses with big bone fractures have low chance to live mainly due to the lake of a proper treatment strategy. We believe that further attempts in equine bone tissue engineering will probably be required to meet all the needs for the lesion therapies. Therefore in this study we aimed to investigate the osteogenic differentiation capacity of equine adipose-derived stem cells (e-ASCs) on nano-bioactive glass (nBGs) coated poly(l-lactic acid) (PLLA) nanofibers scaffold (nBG-PLLA). Using electrospinning technique, PLLA scaffold was prepared successfully and coated with nBGs. Fabricated nanofibers were characterized by MTT, SEM, and FTIR analyses, and then osteogenic differentiation potential of isolated e-ASCs was investigated by the most key osteogenic markers, namely Alizarin red-S, ALP, calcium content and bone related (RUNX2, Collagen I, Osteonectin, and ALP) gene markers. Our results indicated that nBGs was successfully coated on PLLA scaffold and this scaffold had no negative (p > 0.05) effect on cell growth rate as indicated by MTT assay. Moreover, e-ASCs that differentiated on nBGs-PLLA scaffold showed a higher (p < 0.05) ALP activity, more (p < 0.05) calcium content, and higher (p < 0.05) expression of bone-related genes than that on uncoated PLLA scaffold and TCPS. According to the results, a combination of bioceramics and biopolymeric nanofibers hold valuable promising potentials to use for bone tissue engineering application and regenerative medicine.     

Novel SCN5A variants identified in a group of Iranian Brugada syndrome patients

Brugada syndrome (BrS) is a rare hereditary arrhythmia syndrome that increases an individual’s risk for sudden cardiac death (SCD) due to ventricular fibrillation. This disorder is regarded as a notable cause of death in individuals aged less than 40 years, responsible for up to 40% of sudden deaths in cases without structural heart disease, and is reported to be an endemic in Asian countries. Mutations in SCN5A are found in approximately 30% of patients with Brugada syndrome. This study aimed to investigate mutations in the SCN5A gene in a group of Iranian Brugada syndrome patients. Nine probands (n = 9, male, mean age = 39) diagnosed with Brugada syndrome were enrolled in this study. Exon 2 to 29 were amplified by PCR and subjected to direct sequencing. Eight in silico prediction tools were used to anticipate the effects of non-synonymous variants. Seven known polymorphisms and 2 previously reported disease-causing mutations, including H558R and G1406R, were found in the studied cases. Twenty novel variants were identified: 15 missense, 2 frameshift, 2 synonymous, and one nonsense variants. In silico tools predicted 11 non-synonymous variants to have damaging effects, whereas frameshift and nonsense variants were considered inherently pathogenic. The novel variants identified in this study, alongside previously reported mutations, are highly likely to be the cause of the Brugada syndrome phenotype observed in the patient group. Further analysis is required to understand the physiological effects caused by these variants.

     

Cadmium and lead in rice grains and wheat breads in Isfahan (Iran) and human health risk assessment

This study was conducted to survey the levels of cadmium (Cd) and lead (Pb) in the main foods of Isfahan province (central Iran). The rice grains and wheat breads were collected from Isfahan city and villages around the Isfahan and Mobarakeh Steel companies. The food samples were wet-ashed by heating in the presence of concentrated nitric acid and hydrogen peroxide. The concentrations of Cd and Pb were determined by inductively coupled plasma-optical emission spectrometer (ICP-OES). The potential exposure risks were then estimated. Levels of Cd in the rice grains and Pb in the investigated foods (except Sangak beard) were above the maximum levels as set by the Codex Alimentarius and National standards of Iran. The wheat bread samples in Isfahan city and Mobarakeh Steel regions presented higher estimated weekly intake (EWI) of Pb (40.93 and 35.35 µg kg^–1 body weight, respectively) compared to other foods. The EWI for Cd and Pb in most samples was considerably above than the provisional tolerable weekly intake. In most cases, the target hazard quotients values were above one and consequently the consumption of foods in the investigated regions was a potentially serious health risk caused by exposure to the crops contaminated with Cd and Pb.     

Simultaneous Application of Rhizobium Strain and Melatonin Improves the Photosynthetic Capacity and Induces Antioxidant Defense System in Common Bean (Phaseolus vulgaris L.) Under Salinity Stress

Melatonin (N-acetyl-5-methoxytryptamine) as a natural biostimulating substance provides a number of benefits in stimulating plant growth in stress situations due to its natural antioxidant capacity. Rhizobia also play crucial roles in supporting plant growth under environmental stress conditions. The overall goal of this research is to study the possible positive effects of melatonin and rhizobacterium in enhancing the growth and salinity tolerance of common bean. To accomplish this objective, we conducted in vitro experiment to select the optimal melatonin concentration and treatment time of seed priming for the best germination. Also, a greenhouse experiment was performed to investigate the effect of melatonin pre-treatment applied before rhizobial inoculation to improve the fitness of common bean under salinity stress. The experiment was conducted using a completely randomized factorial design with six replications and three treatments: priming treatments (melatonin priming (PM100), hydro priming (PH) and dry (PD)), salinity (0, 4, 8, 10 and 16 dS m^?1) and Rhizobium strain (inoculated (RS?+) and uninoculated (RS?)). Our results showed that melatonin priming promoted bacterial colony size in Petri-dishes. The interactive effects of melatonin and RS?+?was found to alleviate reactive oxygen species (ROS) burst, and hence protect common bean chlorophylls a, b and carotenoid and photosynthetic activity and decrease malondialdehyde content through activation of antioxidant enzymes (superoxide dismutase, peroxidase, catalase and ascorbate peroxidase), facilitation of soluble protein synthesis, maintenance of Na⁺ and K⁺ homeostasis, and finally increase shoot dry weight (33.2, 39.5 and 31.5%) and seed yield (78.6, 91 and 54.2%) compared to the combination of PD and RS- treatments under 0, 4 and 8 dS m^?1 salinity levels, respectively. Thus, our findings suggest that seed priming with melatonin, especially 100 µM melatonin is an effective strategy that can be used to enhance salt tolerance in common bean.