Toxoplasma gondii: Prolonged in-vitro maintenance of virulent tachyzoites in fluid media at low temperatures

Background: Prolonged maintenance of infective Toxoplasma gondii tachyzoites (T.g.T.) is an important subject for research purposes. This study aimed to evaluate four serum free fluid media for prolonged in vitro maintenance of T.g.T.Methods: The four fluid media Phosphate buffered saline (PBS) pH 7.2 and Roswell Park Memorial Institute (RPMI-1640) with or without 3% fetal bovine serum (FBS) were evaluated for maintenance of virulent T.g.T. The four media were tested after incubation at three different temperature degrees in the darkness.Results: Prolonged maintenance period for infective T.g.T. was recorded especially in the absence of FBS supplement. RPMI without FBS was able to maintain infective T.g.T. for 16 days post incubation (dpi) at refrigerator temperature. This period decreased to 10 dpi and 6 dpi after incubation in the same media at 18–22 oC and 37 oC, respectively. Cultivation of T.g.T. in RPMI supplemented with 3% FBS and in PBS proved to maintain infective T.g.T. for 14 dpi at refrigerator temperature, and for 9 and 5 dpi when the two media were incubated at 18–22 oC and 37 oC, respectively. Shorter periods for keeping the T.g.T. infectivity were recorded using PBS supplemented with 3% FBS under all tested temperature conditions.Conclusion: This method allows economic long-lasting maintenance of tachyzoites for 16th dpi in RBMI that can be reactivated by reinoculation in mice.Keywords:  Toxoplasma gondii, Tachyzoites, Fluid media, Temperatur

Protective Effects of Flavone from Tamarix aphylla against CCl4-Induced Liver Injury in Mice Mediated by Suppression of Oxidative Stress, Apoptosis and Angiogenesis

The current study aimed to investigate, for the first time, the beneficial effects of 3,5-dihydroxy-4′,7-dimethoxyflavone isolated from Tamarix aphylla L. against liver injury in mice. Liver injury was induced by intraperitoneal (i.p.) injection of carbon tetrachloride (CCl4) at a dose of 0.4 mL/kg mixed in olive oil at ratio (1:4) twice a week for 6 consecutive weeks. The administration of CCl4 caused significant histopathological changes in liver tissues while the pre-treatment with the flavone at dose of 10 and 25 mg/kg ameliorated the observed liver damages. Also, it markedly reduced hepatic malondialdehyde (MDA) level as well as increased the activities of liver superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (Gpx) compared with their recorded levels in CCl4 model group. Moreover, the immunohistochemical analysis demonstrated the enhancement in the protein level of B-cell lymphoma-2 (Bcl-2) while the protein levels of cysteine-aspartic acid protease-3 (caspase-3), Bcl-2-associated x protein (Bax), transforming growth factor-β1 (TGF-β1) and CD31 were suppressed following the flavone treatement. These results suggest that the flavone can inhibit liver injury induced in mice owning to its impact on the oxidation, apoptotic and angiogenesis mechanisms. Further pharmacological investigations are essential to determine the effectiveness of the flavone in human

Influence of the analysis technique on estimating hepatic iron content using MRI

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134998/1/jmri25317.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134998/2/jmri25317_am.pd

The Motion of a Point Vortex in Multiply Connected Polygonal Domains

We study the motion of a single point vortex in simply and multiply connected polygonal domains. In case of multiply connected domains, the polygonal obstacles can be viewed as the cross-sections of 3D polygonal cylinders. First, we utilize conformal mappings to transfer the polygonal domains onto circular domains. Then, we employ the Schottky-Klein prime function to compute the Hamiltonian governing the point vortex motion in circular domains. We compare between the topological structures of the contour lines of the Hamiltonian in symmetric and asymmetric domains. Special attention is paid to the interaction of point vortex trajectories with the polygonal obstacles. In this context, we discuss the effect of symmetry breaking, and obstacle location and shape on the behavior of vortex motion

Environmental isotonicity improves cold tolerance of Nile tilapia, Oreochromis niloticus, in Egypt

AbstractThe limited ability of Oreochromis niloticus to tolerate low temperatures during winter in temperate and some subtropical region, such as in Egypt, is of major economic concern. The present study was aimed to improve the cold tolerance of Nile tilapia, O. niloticus, by using the well documented phenomena of saving energy consumption for osmoregulation in isotonic medium to decrease the physiological response to cold stress at winter months and may solve the Winter Stress Syndrome (WSS) and the over-wintering problems. Fish which were either pre-acclimated to freshwater or isotonic salinity at 25°C were transferred directly to freshwater or isotonic medium (12‰) at 14°C. Fish were killed 3, 6, 24, 48, 72 and 168h after transfer. In the isotonic medium pre-acclimated fish, it is shown that the effect of cold stress on the increment of plasma glucose level was much lower than that in fresh water. From the observations of Na+, K+, Mg2+-ATPase enzyme activity we conclude that less disturbance of ionic balance caused by cold tolerance was occurred in the isotonic point water than in the fresh water. The results of the acetylcholinesterase specific activity showed that, brain enzyme was inhibited by cold stress, and that the disruption of the cholinergic function induced by cold stress was much more pronounced in fresh water pre-acclimated tilapia than in isotonic point water pre-acclimated fish. Results from this study recommend that pre-acclimation of Nile tilapia, O. niloticus, to an environmental salinity close to the isotonicity, before winter onset, may improve their cold tolerance

The combined effect of environmental thermal drop and isotonicity on metabolic stores of the teleost, Oreochromis niloticus

AbstractFour experimental regimes were designed to test the capacity of the Nile tilapia Oreochromis niloticus to make use of the energy saved form osmoregulation in an isotonic medium in overcoming the Winter Stress Syndrome (WSS). Fish either pre- acclimated to freshwater or isotonic salinity at 25°C were transferred directly to freshwater or an isotonic medium (ca. 12‰) at 14°C. Fish were killed 3, 6, 24, 48, 72 and 168h after transfer. The mobilisation and use of lipids from perivisceral and muscle fat observed in the study seem to be a direct response to cold stress as well as the associated fasting, these effects were salinity dependent being lesser at the isotonic salinity. The energy needs of fish diminish in cold conditions when the salinity of the environment approaches the isotonicity. The absence of any significant changes in muscle and water content indicated that the changes of muscle lipid are true and lipid was the sole source of energy upon thermal drop. The changes of blood haemoglobin levels throughout the four experimental regimes may indicate that the isotonic medium acclimated tilapia showed less haematological disturbance due to cold stress. Results from this experimental study recommend that the pre-acclimation of the Egyptian strain of Nile tilapia, O. niloticus, to an environmental salinity close to the isotonicity may improve fish cold tolerance

Specific Cellular Immune Response and Cytokine Patterns in Patients Coinfected with Hepatitis C Virus and Schistosoma mansoni

Patients coinfected with hepatitis C virus (HCV) and Schistosoma mansoni show high incidence of viral persistence and accelerated fibrosis. To determine whether immunological mechanisms are responsible for this alteration in the natural history of HCV, the HCV-specific peripheral CD4+ T cell responses and cytokines were analyzed in patients with chronic hepatitis C monoinfection, S. mansoni monoinfection, or HCV and S. mansoni coinfection. An HCV-specific CD4+ proliferative response to at least 1 HCV antigen was detected in 73.3% of patients infected with HCV, compared with 8.6% of patients coinfected with HCV and S. mansoni. Stimulation with HCV antigens produced a type 1 cytokine profile in patients infected with HCV alone, compared with a type 2 predominance in patients coinfected with HCV and S. mansoni. In contrast, there was no difference in response to schistosomal antigens in patients infected with S. mansoni alone, compared with those coinfected with HCV and S. mansoni. These findings suggest that the inability to generate an HCV-specific CD4+/Th1 T cell response plays a role in the persistence and severity of HCV infection in patients with S. mansoni coinfectio

Spectral Studies on Some Hydrazones of 6-Formyl-7-hydroxy-5-methoxy-2-methylchromone

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Synthesis, Characterization, and In Vivo Anti-Cancer Activity of New Metal Complexes Derived from Isatin-N(4)antipyrinethiosemicarbazone Ligand Against Ehrlich Ascites Carcinoma Cells

The current study aimed to synthesize new metal coordination complexes with potential biomedical applications. Metal complexes were prepared via the reaction of isatin-N(4)anti- pyrinethiosemicarbazone ligand 1 with Cu(II), Ni(II), Co(II), Zn(II), and Fe(III) ions. The obtained metal complexes 2–12 were characterized using elemental, spectral (1H-NMR, EPR, Mass, IR, UV-Vis) and thermal (TGA) techniques, as well as magnetic moment and molar conductance measurements. In addition, their geometries were studied using EPR and UV–Vis spectroscopy. To evaluate the in vivo anti-cancer activities of these complexes, the ligand 1 and its metal complexes 2, 7 and 9 were tested against solid tumors. The solid tumors were induced by subcutaneous (SC) injection of Ehrlich ascites carcinoma (EAC) cells in mice. The impact of the selected complexes on the reduction of tumor volume was determined. Also, the expression levels of vascular endothelial growth factor (VEGF) and cysteine aspartyl-specific protease-7 (caspase-7) in tumor and liver tissues of mice bearing EAC tumor were determined. Moreover, their effects on alanine transaminase (ALT), aspartate transaminase (AST), albumin, and glucose levels were measured. The results revealed that the tested compounds, especially complex 9, reduced tumor volume, inhibited the expression of VEGF, and induced the expression of caspase-7. Additionally, they restored the levels of ALT, AST, albumin, and glucose close to their normal levels. Taken together, our newly synthesized metal complexes are promising anti-cancer agents against solid tumors induced by EAC cells as supported by the inhibition of VEGF and induction of caspase-7

Melittin Exerts Beneficial Effects on Paraquat-Induced Lung Injuries in Mice by Modifying Oxidative Stress and Apoptosis

Melittin (MEL) is a 26-amino acid peptide with numerous biological activities. Paraquat (PQ) is one of the most widely used herbicides, although it is extremely toxic to humans. To date, PQ poisoning has no effective treatment, and therefore the current study aimed to assess for the first time the possible effects of MEL on PQ-induced lung injuries in mice. Mice received a single intraperitoneal (IP) injection of PQ (30 mg/kg), followed by IP treatment with MEL (0.1 and 0.5 mg/kg) twice per week for four consecutive weeks. Histological alterations, oxidative stress, and apoptosis in the lungs were studied. Hematoxylin and eosin (H&E) staining indicated that MEL markedly reduced lung injuries induced by PQ. Furthermore, treatment with MEL increased superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activity, and decreased malonaldehyde (MDA) and nitric oxide (NO) levels in lung tissue homogenates. Moreover, immunohistochemical staining showed that B-cell lymphoma-2 (Bcl-2) and survivin expressions were upregulated after MEL treatment, while Ki-67 expression was downregulated. The high dose of MEL was more effective than the low dose in all experiments. In summary, MEL efficiently reduced PQ-induced lung injuries in mice. Specific pharmacological examinations are required to determine the effectiveness of MEL in cases of human PQ poisoning