N-acetylcysteine protects against cuprizone-induced demyelination: histological and immunohistochemical study

Myelination is a sequential process that is tightly controlled by a number of intrinsic and extrinsic factors. Any CNS disease in which the neuronal myelin sheath is damaged is referred to as demyelinating disease. The present work was designed to study the histopathological, ultrastructural and immunohistochemical changes in rat brain, mainly corpus callosum (CC), following oral administration of cuprizone (CPZ), and the role of N-acetylcysteine (NAC) in reducing these changes. Demyelination was induced by CPZ administration for short (4Ws) and long (8Ws) periods.  NAC was given concomitantly and sequentially for similar periods. Spontaneous recovery after cessation of CPZ followed by no medication was also investigated. At the end of each experimental period, both cerebral hemispheres were extracted and prepared for light and electron microscopic examination and immuno-histochemical study.  The obtained results showed a direct proportion between the duration of CPZ administration and the severity of demyelination. The co-administration of CPZ and NAC, had a fair protective impact that was stronger than the sequential administration of the two drugs. Incomplete spontaneous remyelination was observed after cessation of CPZ, being more evident in short than in long period group, indicating that when CPZ administration is prolonged, remyelination is delayed. In the light of the above results, it could be concluded that NAC has neuroprotective effects and has the potential to be a novel therapeutic approach for the treatment of demyelinating diseases such as multiple sclerosis; however, treatment should begin as soon as the disease manifests

Evaluation of Bio-Friendly Formulations From Siderophore-Producing Fluorescent \u3ci\u3ePseudomonas\u3c/i\u3e as Biocontrol Agents for the Management of Soil-Borne Fungi, \u3ci\u3eFusarium oxysporum\u3c/i\u3e and \u3ci\u3eRhizoctonia solani\u3c/i\u3e

Secretion of siderophores by Pseudomonas aeruginosa F2 and P. fluorescens JY3 was evaluated on chrome azurol S (CAS) agar plates and their inhibitory effect was inspected against Fusarium oxysporum and Rhizoctonia solani. Production of siderophores as biocontrol agents from F2 and JY3 was accomplished in two optimized media. Afterward, cell-free supernatants of the bacterial cultures containing siderophores were used for the preparation of two bio-friendly formulations for the management of F. oxysporum and R. solani under greenhouse conditions. The investigated bacterial isolates, F2 and JY3, showed antagonistic activity in vitro against F. oxysporum and R. solani and produced siderophores in optimized media with high efficiency. Colonies of both bacterial isolates were grown exponentially with a constant specific growth rate of 0.07 h−1 and 0.27 h−1, correspondingly. Siderophores estimated in 10 µL reached their highest value of 16.95% at 47 h and 19.5% at 48 h for isolate F2 and JY3, respectively. Formulations of siderophore-generating F2 and JY3 reduced damping-off caused by F. oxysporum by 40% and 80%, while the reduction percentage of damping-off caused by R. solani reached 87.5% and 62.5%, correspondingly. Moreover, both formulations encouraged the growing of wheat plants where the fresh and dry weight of shoots and roots were increased compared to the treatment with each fungus. In conclusion, bio-friendly formulations resulting from this investigation can play an active role in managing soil-borne diseases

Purification And Characterization Of Marine Bacillus Thuringiensis N2 Urease

Urease was purified to homogeneity from Bacillus thuringiensis N2using different purification steps namely, 55% acetone precipitation,DEAE-Sephadex A50 anion exchange column and Sephadex G120-200gel filtration chromatography. The enzyme was purified 95.27 fold andshowed a final specific activity of 10.48 U/mg proteins with a yield 56%. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS/PAGE) of the purified enzyme revealed a single protein band of97.4 KDa molecular weight. The enzyme showed thermal stability at 50°C and has maximum activity at 25°C, pH 8 and incubation period of 15 min.. A lineweaver- aBurk analysis gave a Km of 2.94 mM and Vmax of 25 μmol/ml/min. The urease activity was enhanced by addition of CuCl2. The enzyme proved to be rich in cysteine, methionine and tryptophan while it contained low amounts of glycine, alanine, and β-alanine.Key words : BT urease , enzyme kinetics , enzyme purificatio

Effects of storage time and temperature on the infectivity and effectiveness of Frankia entrapped in polyacrylamide gel

frankia strain HFP ArI3 which had been preserved for 27 months by being lyophilized, frozen in glycerol, or stored in complex medium was successfully used as an inoculum after being subcultured for inducing nodulation and nitrogen fixation of Alnus rubra. Glycerol-preserved HFP ArI3 produced significantly lower rates of nitrogenase activity than did lyophilized or complex-medium-preserved inocula. Bacteria that had been preserved by all three methods were successfully induced to fix atmospheric nitrogen by being cultured in nitrogen-free medium. Subculturing of these cells in nitrogen-free medium a second and third time yielded increasing rates of nitrogenase activity. Initial nitrogenase activity was detected on days 5, 4, and 3 during the first, second, and third subcultures after preservation, respectively. Maximum activity was observed on days 11, 10, and 8 during the first, second, and third subcultures, respectively. A description is given of standard culture techniques used in our laboratory for Frankia isolates, and methods used to distribute Frankia cultures by mail are described

الفلورا الفطرية للبلح الجاف فى صعيد جمهورية مصر العربية: 2- الفطريات المحبة العربية

19 fungal species which belong to 8 genera were collected from 30 dry date samples of which 9 species appeared on all sucrose concentrations (20%, 40% and 60%) namely, Aspergillus amstelodami, A. niger, A. raber, A. sydowii, Penicillium chevalierii, p. brevi-compactum, Humicola grisea, AItemaria altervata and Rhizopus stolonifer. When 17 species of the collected fungi were tested for their osmophilic abilities, they were classified into 4 groups: a) Highly osmophilic: A. niger, A. ruber and A. amstelodami. b) Fairly osmophilic: A. flavus, P. funiculosum and F. oxysoporum. c) Weakly osmophilic: A. terreus, P. dtnnum, F. so/am and Paedlomyces variotii. d) Osmotolarent: F. moniliforme, F. equiseti, Ulocladium botrytis, Rhizopus stolonifer, Chaetomium globosum, Altemaria alternata and Drechslera biseptata.الهدف من هذ ا البحث هو عزل وتعريف الفطريات المحبة للأسموزية من 30 عينة من البلح الجاف تم جمعها من بعض المناطق في صعيد مصر ، وكذلك تضمن البحث دراسة قدرة بعض الفطريات المعزولة على تخمل درجات مختلفة من الأسموزية وذلك عند زراعتها على أوساط غذائية تحتوي على تركيزات 20% ، 40% ، 60% من السكروز . ولقد أمكن التوصل إلى بعض النتائج نوجزها فيما يلي : 1- تم عزل وتعريف 19 نوعا تنتمي إلى 8 أجناس من الفطريات المحبة للأسموزية . وقد أمكن التعرف على تسعة أنواع منها كانت لها القدرة على النمو عند جميع تركيزات السكروز . 2- عن دراسة مدى تحمل 17 نوعا من الفطريات على النمو عند جميع التركيزات أمكن تقسيمها إلى 4 مجموعات رئيسية هي كما يلي : ‌أ. فطريات عالية الأسموزية (3 أنواع ) وتنمو بصورة أفضل عند تركيز 60% سمكروز. ‌ب. فطريات متوسطة الأسموزية (3 أنواع ) وتنمو بصورة أفضل عند تركيز 45%سكروز. ‌ج. فطريات ضعيفة الأسموزية (5أنواع ) وهي التي تنمو بصورة أفضل عند تركيز 20%سكروز. ‌د. فطريات تتحمل الأسموزية (7 أنواع ) وهي التي تستطيع النمو بصورة واحدة عند جميع التركيزات

الفلورا الفطرية للبلح الجاف في صعيد جمهورية مصر العربية 1- الفطريات الوسطية والمحتملة للحرارة

Twenty-eight species which belong to 16 genera were identified from 30 dry date samples collected from Upper Egypt and plated at 28°C. Aspergillus, PeniciUium and Fusanum were the most common genera on the carposphere and the carpoplane. A. niger, p. rugulosum and F. solaniweTG the most common species on the carposphere while A. niger and Alternaria alternata were prevalent on the carpoplane. At 45°C, six species, in addition to one variety of Humicola grisea, which belong to five genera were collected from the carposphere and carpoplane of 30 date samples and A. fumigatus was the most common species. There is no correlation between the fungal composition, density of populations and the chemical composition of the dates of the five varieties.الهدف من هذا البحث هو دراسة تصنيفية شاملة للفطريات التي تنمو على أسطح (الكاربوسفير) وبشرة (الكاربوبلين ) شاملة عينة من البلح الجاف تم جمعها من مناطق مختلفة من صعيد مصر هذا بالإضافة إلى المحتوى الكيميائي لهذه العينات وقد أمكن التوصل إلى بعض النتائج الهامة نوجزها فيما يلي : 1- عند 28 م تم عزل وتعريف 28 نوعا تنتمي إلى 16 جنسا من الفطريات كان أكثرها شيوعا هي اسبرجيللس نيجر ، بنسليوم ريجيولوزم وفيوزاريوم سولاني على الكاربوسفير بينما كانت فطريات اسبرجلس نيجر ، الترناريا الترناتا هي أكثرها شيوعا على الكاربوبلين . 2- عند45 م تم عزل وتعريف ستة أنواع بالإضافة إلى صنف واحد من الفطريات المتحملة للحرارة وكان أكثرها شيوعا هو فطر الاسبرجلس فيوميجاتس . 3- أظهرت النتائج عدم وجود علاقة بين كل من التركيب الكيميائي للبلح الجاف والمحتوى الفطري لهذه العينات