43 research outputs found
Thioredoxin Is a New Target for the Phytotoxicity of Small Lactone Mycotoxins, Patulin and Penicillic Acid on Maize Seedlings
The phytotoxic mechanisms of patulin (PAT) and penicillic acid (PA) have not been identified unambiguously. This study aims to clarify their effects on thioredoxins (Trxs). Aflatoxin B1 (AFB1), PAT and PA were isolated by solvent extraction and chromatographic techniques from the cultures of Aspergillus flavus Z2 (LC171449), Penicillium vulpinum CM1 and Aspergillus ochraceus EMCC516, respectively. The three mycotoxins showed phytotoxicity to the germination of maize seeds, which was manifested by inhibiting radicle and coleoptile emergence, in addition to their toxic effects on fresh weights and root and shoot lengths. The phytotoxicity of AFB1 and PAT was greater than that of PA. Due to the central roles exhibited by plant Trxs in cellular metabolic activities, they were tested as target proteins for PAT and PA using AFB1 as positive control. In vivo studies showed that the mycotoxins significantly reduced Trx activity measured in the roots and shoots of maize seedlings. PAT showed greater Trx-inhibiting activity than PA and AFB1. In vitro studies of the mycotoxins on Trx y1 (from Arabidopsis thaliana) and thioredoxin reductase (Tr, from rat liver) activities confirm the results of in vivo studies. The inactivation of Trx with PAT and PA was reduced in the presence of glutathione (GSH). Data obtained suggest that lactone mycotoxins are more highly reactive with simple low-molecular-weight thiols (like GSH) than with complex ones (like Trx)
Solar Chimney Power Plants: A Mini Review
The main investigations of a novel solar thermal application known as SCPP are summarized in this paper. It is a method of producing electricity from solar energy that relies on the fact that air rises when it is heated. An adequate position within a tall chimney can be utilized to position a turbine to turn it, creating an updraft that can be used to generate power. This system\u27s specifications, design, construction, and use are all covered in the paper along with experimental and analytical research related to it. It also emphasizes the development and execution of SCPP programs
Non-invasive index of liver fibrosis induced by alcohol, thioacetamide and schistosomal infection in mice
<p>Abstract</p> <p>Background</p> <p>Non invasive approaches will likely be increasing utilized to assess liver fibrosis. This work provides a new non invasive index to predict liver fibrosis induced in mice.</p> <p>Methods</p> <p>Fibrosis was generated by thioacetamide (TAA), chronic intake of ethanol, or infection with <it>S. mansoni </it>in 240 mice. Both progression and regression of fibrosis (after treatment with silymarin and/or praziquantel) were monitored. The following methods were employed: (i) The METAVIR system was utilized to grade and stage liver inflammation and fibosis; (ii) Determination of hepatic hydroxyproline and collagen; and (iii) Derivation of a new hepatic fibrosis index from the induced changes, and its prospective validation in a group of 70 mice.</p> <p>Results</p> <p>The index is composed of 4 serum variable including total proteins, γ-GT, bilirubin and reduced glutathione (GSH), measured in diseased, treated and normal mice. These parameters were highly correlated with both the histological stage and the grade. They were combined in a logarithmic formula, which non-invasively scores the severity of liver fibrosis through a range (0 to 2), starting with healthy liver (corresponding to stage 0) to advanced fibrosis (corresponding stage 3).Receiver operating characteristic curves (ROC) for the accuracy of the index to predict the histological stages demonstrated that the areas under the curve (AUC) were 0.954, 0.979 and 0.99 for index values corresponding to histological stages 1, 2 and 3, respectively. Also, the index was correlated with stage and grade, (0.947 and 0.859, respectively). The cut off values that cover the range between stages 0-1, 1-2 and 2-3 are 0.4, 1.12 and 1.79, respectively. The results in the validation group confirmed the accuracy of the test. The AUROC was 0.869 and there was good correlation with the stage of fibrosis and grade of inflammation.</p> <p>Conclusion</p> <p>The index fulfils the basic criteria of non-invasive marker of liver fibrosis since it is liver-specific, easy to implement, reliable, and inexpensive. It proved to be accurate in discriminating precirrhotic stages.</p
In-vitro Antifungal Activities of Kombucha Tea Culture Supernatant Combined with Voriconazole against Vulvovaginal Candidiasis Clinical Isolates
Objective: To investigate the antifungal activity of voriconazole, with and without Kombucha tea culture, against Candida strains isolated from vulvovaginal candidiasis.
Material and Methods: The study included 150 females, within child-bearing periods, complaining of valvovaginal candidiasis. Candida strains were isolated, and identified by conventional microbiological methods; and confirmed by Viteck-2 System. The sensitivity of the isolates to voriconazole was performed, via the Disc diffusion method. Resistant strains were then subjected to minimum inhibitory concentrations (MIC) investigation of voriconazole alone, and in combination with a Kombucha tea culture via the broth micro-dilution method in concentrations ranging from 0.0048 to 10 μg/ml. The ability of voriconazole, with and without Kombucha, to eradicate Candida biofilms were investigated using a crystal violet absorbance assay.
Results: Eighty-nine strains were isolated. From these 60 isolates showed variable resistance patterns (57 were voriconazole resistant, and 3 had dose-dependent susceptability). Kombucha significantly decreased the MIC50 of voriconazole against all strains from 5 to 0.625 μg/ml (p-value<0.01); additionally, MIC90 were reduced from 10 to 1.25 μg/ml (p-value =0.000). Voriconazole at a concentration of 0.156 μg/ml succeeded in eradicating biofilms formed by 18 strains after adding a Kombucha tea supernatant versus zero strains when using Voriconazole alone.
Conclusion: Kombucha Black tea cultures could be promising antifungal agents in the treatment of vulvovaginal candidiasis
Detection of Cancer Stem Cells in Colorectal Cancer: Histopathological and Immunohistochemical Study
BACKGROUND: Growing evidence supports the notion that the onset of tumorigenesis could occur through cancer stem cells (CSCs). These tumour cells show low proliferative rates, high self-renewal capacity, propensity to differentiate into active proliferating tumour cells & resistance to chemoradiotherapy thus, possibly causing local recurrences & metastasis formation. CD44 has been used as a marker to isolate CSCs from colorectal carcinoma (CRC).AIM: To investigate the immunohistochemical expression of cancer stem cells marker (CD44) in CRC and correlate its expression with the clinicopathological aspects, TNM staging and modified Dukes’ classification.MATERIALS AND METHODS: Tumour biopsies from colectomy specimens of 60 patients with CRC were stained with hematoxylin-eosin for histological evaluation then immunostained with monoclonal antibodies against CD44 which was detected in term of negative or positive expression.RESULTS: CD44 was demonstrated in 58.3% (35/60) of cases and showed statistically significant correlation with tumour site and histological type (p-value < 0.05). However, CD44 showed statistically insignificant inverse correlation with tumour invasiveness (T), lymph node status (N), grade, TNM stage grouping and modified Dukes’ classification, while it was directly correlated with distant metastasis (M) (p-value > 0.05). Chi-square /Fisher exact test proportion independence and the p-value are set significant at 0.05 level.CONCLUSION: the CD44 rate of expression is higher in the colon than rectum and in adenocarcinoma than mucinous and undifferentiated carcinoma. CD44 showed statistically insignificant relation with T, N, M, grade, TNM stage grouping and modified Dukes’ classification
Mycotoxins: Producing Fungi and Mechanisms of Phytotoxicity
Mycotoxins are secondary fungal metabolites, toxic to humans, animals and plants. Among the hundreds of known mycotoxins, aflatoxins, citrinin, patulin, penicillic acid, tenuazonic acid, ochratoxin A, cytochalasins, deoxynivalenol, fumonisins, fusarin C, fusaric acid, and zearalenone are considered the types that most contaminate cereal grain. The majority of the mycotoxins in these groups are produced by three fungal genera: Aspergillus, Penicillium and Fusarium. These metabolites primarily affect the seed quality, germination, viability, seedling vigour, growth of root and cleoptile. Additionally, since the fungi responsible for the production of these mycotoxins are often endophytes that infect and colonize living plant tissues, accumulation of mycotoxins in the plant tissues may at times be associated with development of plant disease symptoms. The presence of mycotoxins, even in the absence of disease symptoms, may still have subtle biological effects on the physiology of plants. Several studies highlight the toxic effects of mycotoxins on animals and cell lines but little is known about the mode of action of most of these metabolites on plant cells. The most important mycotoxins with phytotoxic effects and their producers in addition to their discovery are briefly outlined below and will be addressed in this article
Effect of Patulin from Penicillium vulpinum on the Activity of Glutathione-S-Transferase and Selected Antioxidative Enzymes in Maize
The mycotoxin patulin (PAT) was purified from Penicillium vulpinum CM1 culture that has been isolated from a soil cultivated with maize. The effect of PAT and of a fungal culture filtrate on the activities of glutathione-S-transferase (GST) and some antioxidant enzymes viz. ascorbate peroxidase (APX), glutathione reductase (GR), dehydroascorbate reductase (DHAR) and monodehydroascorbate reductase (MDHAR) was investigated in roots and shoots of 8-day-old maize seedlings. PAT and culture filtrate caused significant reduction effects in a dose-related manner on the total GST activity. Upon application of the high PAT concentration (25 μg·mL−1) and of the concentrated fungal filtrate (100%, v/v), the reduction in GST activity of roots was 73.8–76.0% and of shoots was 60–61.7%. Conversely, significant increases in the activities of antioxidant enzymes were induced. Application of 25 μg·PAT·mL−1 increased APX, GR, DHAR, and MDHAR activity of root by 2.40-, 2.00-, 1.24-, and 2.16-fold, respectively. In shoots, the enzymatic activity was increased by 1.57-, 1.45-, 1.45-, and 1.61-fold, respectively. Similar induction values of the enzymatic activity were obtained upon application of the concentrated fungal filtrate. This is the first report describing the response of GST and antioxidant enzyme activities of plant cells to PAT toxicity
Some physicochemical analyses of kefir produced under different fermentation conditions
365-372This study presents physicochemical attributes of kefir under different cultural conditions. Maximum values of kefirbiomass and kefiran were achieved when 100 ml of skimmed cows’ milk (pH 6)/250 ml glass container was fermented with 5 gfresh kefir grains after stationary incubation at 30°C for 120 h. Amino acids profile in kefir included most types of amino acidsexcept asparagine, glutamine and tryptophan. Analysis of kefir organic acids indicated that lactic acid had highest concentration(7.30 mg/ml), followed by acetic acid (6.50 mg/ml) and maleic acid (4.00 mg/ml). Production of ethanol was high, reaching aconcentration value of 0.22% (w/w). Highest kefir biomass and kefiran concentration were maintained when fermentation processwas carried out using a medium formulation composed of: lactose, 40; ammonium chloride, 4.0; KH2PO4, 1.0 and MgSO4.7H2O,5.0 g/l. Physicochemical analyses of kefir resulted from fermentation of either skimmed milk or medium formulation indicated thatboth kefiran production and kefir filtrate viscosity were growth associated, while increase in titratable acidity was largely relatedto lactic acid production