Neuroprotective effects of allopurinol on spinal cord injury in rats: a biochemical and immunohistochemical study

Background: Lesion in spinal cord causes a cascade of events such as the apoptosis of neurons and eventually, neurological dysfunction. Neurologic damage developing after acute spinal cord injury is also related with necrosis and free radical formation. Allopurinol, a xanthine oxidase inhibitor, was shown to have protective effects in several studies. B-cell lymphoma 2 (Bcl-2) family proteins regulate apoptosis. Apoptosis causes the death of neuronal cells, particularly neurons and oligodendrocytes in the spinal cord after lesion. Glial fibrillary acidic protein (GFAP) takes part in astrocyte and neuronal interconnection and synaptic transmission. Materials and methods: Male Sprague Dawley rats (n = 30) were divided as control, trauma, and trauma + allopurinol (i.p., 50 mg/kg of body weight) groups. Animals were applied a surgical procedure causing spinal cord injury and treated for 7 days then sacrificed under anaesthesia. The spinal cords were dissected, measurements of myeloperoxidase, malondialdehyde and glutathione were performed, remaining parts were fixed in 10% formaldehyde solution for histological and immunohistochemical evaluations. Results: Biochemical results exhibited an increase in myeloperoxidase levels in trauma group but a decrease in the allopurinol treatment group similar to malondialdehyde levels. Degenerative changes in multipolar and bipolar neurons together with apoptotic changes in some glial cells were observed in the trauma group whereas, mild degenerative changes were observed after allopurinol treatment. In the trauma group, negative GFAP expression in multipolar versus bipolar neuronal processes with a reduction in glial processes around blood vessels and positive GFAP expression were observed but, a regular and parallel positive GFAP expression of glial processes around blood vessels in the allopurinol treated group was apparent. Trauma group depicted a positive Bcl-2 expression in glial cells and in motor and bipolar neurons. On the contrary, negative Bcl-2 expression was noticed in the trauma + allopurinol group. Conclusions: This study is of importance to understand the effects of allopurinol in preventing degenerative changes in nerve and glial cells related to spinal cord injuries

Biochemical and immunohistochemical investigations on bone formation and remodelling in ovariectomised rats with tamoxifen citrate administration

Background: Osteoporosis results with the imbalance between osteoblastic formation and osteoclastic resorption, resulting in susceptibility to bone fractures. Ovariectomy leads to osteoporosis by triggering alterations in bone formation and structure. Tamoxifen as an anti-oestrogen is used for adjuvant therapy especially in metastatic diseases and known to have a bone mass protective effect after ovariectomy. Materials and methods: An animal model of ovariectomy induced osteoporosis after tamoxifen citrate administration was studied via biochemical and immunohistochemical methods. Female Wistar albino rats (n = 45), selected according to their oestrous cycle, were divided into three groups; I — control, II — ovariectomy, III — ovariectomy + tamoxifen. Following ovariectomy, tamoxifen citrate (10 mg/kg) was given intraperitoneally daily for 8 weeks. At the end of the period, animals were sacrificed under anaesthesia, blood samples were taken to measure oestrogen, calcium, and alkaline phosphate. Tibia bone samples were fixed in formalin solution and decalcified with 5% ethylene-diamine tetra acetic acid. After the routine histological follow up, samples were embedded in paraffin and cut with a microtome for semi-thin sections. Primary antibodies osteonectin and osteopontin were applied to sections and examined under light microscope. Results: As a consequence, when oestrogen and calcium data were compared there was a decrease in ovariectomy group with an increase in alkaline phosphatase. In ovariectomy + tamoxifen group, these values were close to the control group. Osteonectin was observed to promote bone formation by influencing collagen fibre formation, extracellular matrix development, osteoblast differentiation and the capacity to affect osteoclast activity. Conclusions: It has been suggested that osteopontin, the cytokine and cell binding protein, stimulates cellular signalling pathways, induces bone remodelling and acts in osteoporosis

Assessing of growth, antioxidant enzymes, and phytohormone regulation in Cucurbita pepo under cadmium stress

One of the major problems worldwide is soil pollution by trace metal elements, which limits plant productivity and threatens human health. In this work, we have studied the effect of different concentrations of cadmium on Cucurbita pepo plants, evaluating different physiological and biochemical parameters: hormone signaling, metabolite concentration (malondialdehyde and hydrogen peroxide) and, in addition, the antioxidant enzyme activities of catalase and superoxide dismutase were evaluated. The production of biomass decreased under the Cd‐stress. The results showed that C. pepo accumulates higher amounts of Cd2+ in roots than in shoots and fruits. Cd2+ differently affected the content of endogenous phytohormones. Furthermore, data suggest an essential involvement of roots in the regulation of tolerance to trace elements. As a result, indole acetic acid content increased in roots of treated plants, indicating that this phytohormone can stimulate root promotion and growth under Cd‐stress. Similarly, salicylic acid content in roots and shoots increased in response to Cd2+, as well as abscisic acid levels in roots and fruits. In roots, the rambling accumulation pattern observed for jasmonic acid and salicylic acid suggests the lack of a specific regulation role against trace element toxicity. The activity of catalase and superoxide dismutase decreased, disrupted by the metal stress. However, the proline, malondialdehyde and hydrogen peroxide content significantly increased in Cd2+in all the analyzed tissues of the stressed plants. All these data suggest that C. pepo plants are equipped with an effective antioxidant mechanism against oxidative stress induced by cadmium up to a concentration of 500 μM

Microencapsulation of melaleuca alternifolia (tea tree) oil by using simple coacervation Method)

Glutaraldehyde (GA) crosslinked gelatin (G) microcapsules containing tea tree oil (TTO) were prepared by the simple coacervation technique. The effects of variations in concentrations of the G, TTO and GA used during the microencapsulation process, on the oil load of the microcapsules, the oil content, the encapsulation efficiency and the release rate of oil were determined. The size distribution and the morphology of the microcapsules were characterized by optical and scanning electron microscopy. It was determined by FTIR studies that there was no evidence for any significant interaction between G and TTO. © 2011 Allured Business Media

Ångström- and Nano-scale Pore-Based Nucleic Acid Sequencing of Current and Emergent Pathogens

State-of-the-art nanopore sequencing enables rapid and real-time identification of novel pathogens, which has wide application in various research areas and is an emerging diagnostic tool for infectious diseases including COVID-19. Nanopore translocation enables de novo sequencing with long reads (\u3e 10 kb) of novel genomes, which has advantages over existing short-read sequencing technologies. Biological nanopore sequencing has already achieved success as a technology platform but it is sensitive to empirical factors such as pH and temperature. Alternatively, ångström- and nano-scale solid-state nanopores, especially those based on two-dimensional (2D) membranes, are promising next-generation technologies as they can surpass biological nanopores in the variety of membrane materials, ease of defining pore morphology, higher nucleotide detection sensitivity, and facilitation of novel and hybrid sequencing modalities. Since the discovery of graphene, atomically-thin 2D materials have shown immense potential for the fabrication of nanopores with well-defined geometry, rendering them viable candidates for nanopore sequencing membranes. Here, we review recent progress and future development trends of 2D materials and their ångström- and nano-scale pore-based nucleic acid (NA) sequencing including fabrication techniques and current and emerging sequencing modalities. In addition, we discuss the current challenges of translocation-based nanopore sequencing and provide an outlook on promising future research directions

Gemcitabine hydrochloride microspheres used for intravesical treatment of superficial bladder cancer: a comprehensive in vitro/ex vivo/in vivo evaluation

Sinem Yaprak Karavana,1 Zeynep Ay Şenyiğit,2 Çağrı Çalışkan,3 Gülnur Sevin,4 Derya İlem Özdemir,2 Yalçın Erzurumlu,5 Sait Şen,6 Esra Baloğlu1 1Department of Pharmaceutical Technology, Faculty of Pharmacy, Ege University, Izmir, Turkey; 2Department of Pharmaceutical Technology, Faculty of Pharmacy, Izmir Katip Çelebi University, Izmir, Turkey; 3Department of Radiopharmacy, Faculty of Pharmacy, Ege University, Izmir, Turkey; 4Department of Pharmacology, Faculty of Pharmacy, Ege University, Izmir, Turkey; 5Department of Biochemistry, Faculty of Pharmacy, Ege University, Izmir, Turkey; 6Department of Pathology, Faculty of Medicine, Ege University, Izmir, Turkey Introduction: Bladder cancer is responsible for more than 130,000 deaths annually worldwide. Intravesical delivery of chemotherapeutic agents provides effective drug localization to the target area to reduce toxicity and increase efficacy. This study aimed to develop an intravesical delivery system of gemcitabine HCl (Gem-HCl) to provide a sustained-release profile, to prolong residence time, and to enhance its efficiency in the treatment of bladder cancer. Materials and methods: For this purpose, bioadhesive microspheres were successfully prepared with average particle size, encapsulation efficiency, and loading capacity of 98.4 μm, 82.657%±5.817%, and 12.501±0.881 mg, respectively. For intravesical administration, bioadhesive microspheres were dispersed in mucoadhesive chitosan or in situ poloxamer gels and characterized in terms of gelation temperature, viscosity, mechanical, syringeability, and bioadhesive and rheological properties. The cytotoxic effects of Gem-HCl solution, Gem-HCl microspheres, and Gem-HCl microsphere-loaded gel formulations were evaluated in two different bladder cancer cell lines: T24 (ATCC HTB4TM) and RT4 (ATCC HTB2TM). Results: According to cell-culture studies, Gem-HCl microsphere-loaded poloxamer gel was more cytotoxic than Gem-HCl microsphere-loaded chitosan gel. Antitumor efficacy of newly developed formulations were investigated by in vivo studies using bladder-tumor-induced rats. Conclusion: According to in vivo studies, Gem-HCl microsphere-loaded poloxamer gel was found to be an effective and promising alternative for current intravesical delivery-system therapies. Keywords: gemcitabine HCl, intravesical chemotherapy, superficial bladder cancer microspheres, mucoadhesive gel, in situ ge