Regulation of cell survival and death during Flavivirus infections

Flaviviruses, ss(+) RNA viruses, include many of mankind's most important pathogens. Their pathogenicity derives from their ability to infect many types of cells including neurons, to replicate, and eventually to kill the cells. Flaviviruses can activate tumor necrosis factor α and both intrinsic(Bax-mediated) and extrinsic pathways to apoptosis. Thus they can use many approaches for activating these pathways. Infection can lead to necrosis if viral load is extremely high or to other types of cell death if routes to apoptosis are blocked. Dengue and Japanese Encephalitis Virus can also activate autophagy. In this case the autophagy temporarily spares the infected cell, allowing a longer period of reproduction for the virus, and the autophagy further protects the cell against other stresses such as those caused by reactive oxygen species. Several of the viral proteins have been shown to induce apoptosis or autophagy on their own, independent of the presence of other viral proteins. Given the versatility of these viruses to adapt to and manipulate the metabolism, and thus to control the survival of, the infected cells, we need to understand much better how the specific viral proteins affect the pathways to apoptosis and autophagy. Only in this manner will we be able to minimize the pathology that they cause.     

Intravascular detection of inflamed atherosclerotic plaques using a fluorescent photosensitizer targeted to the scavenger receptor.

Inflammation plays an important role in the pathophysiology of atherosclerotic disease. We have previously shown that the targeted photosensitizer chlorin (e(6)) conjugated with maleylated albumin (MA-ce6) is taken up by macrophages via the scavenger receptor with high selectivity. In a rabbit model of inflamed plaque in New Zealand white rabbits via balloon injury of the aorto-iliac arteries and high cholesterol diet we showed that the targeted conjugate showed specificity towards plaques compared to free ce6. We now show that an intravascular fiber-based spectrofluorimeter advanced along the -iliac vessel through blood detects 24-fold higher fluorescence in atherosclerotic vessels compared to control rabbits (p < 0.001 ANOVA). Within the same animals, signal derived from the injured iliac artery was 16-fold higher than the contralateral uninjured iliac (p < 0.001). Arteries were removed and selective accumulation of MA-ce6 in plaques was confirmed using: (1) surface spectrofluorimetry, (2) fluorescence extraction of ce6 from aortic segments, and (3) confocal microscopy. Immunohistochemical analysis of the specimens showed a significant correlation between MA-ce6 uptake and RAM-11 macrophage staining (R = 0.83, p < 0.001) and an inverse correlation between MA-ce6 uptake and smooth muscle cell staining (R = -0.74, p < 0.001). MA-ce6 may function as a molecular imaging agent to detect and/or photodynamically treat inflamed plaques.     

Microbiological and Histological Examinations of Endangered Neurergus kaiseri Tissues Displaying Red-leg Syndrome

Presence of the red leg syndrome （RLS） was documented through bacterial and histological examinations in the endangered Kaiser＇s mountain newt Neurergus kaiseri obtained from a pet shop. The individuals which were severely infected showed lethargy, appetite loss, weight loss, abdominal skin redness and skin ulcers on hind legs. This study reveals the presence of two bacteria causing RLS on the skin of captive AT. kaiseri including Proteus vulgaris and Bacillus cereus. Sections of skin in affected areas and internal organs were examined through standard histological procedures. Histologically, epidermal necrosis and ulcers, epidermal gland depletion, myositis and subcutaneous edema, gastric submucosal edema and hepatomegaly were seen. There were also correlations between the microbial infection and structural changes in tissues of Kaiser＇s mountain newt. The severity of the structural changes are related to the level of microbial infection in the target organs and could be sustained by the isolation of P. vulgaris and other pathogens. The presence of the infective bacterial population and their interaction on the skin of the newt may have changed the normal skin flora and facilitate the prevalence of other disease.     

Fifteen novel mutations in the mitochondrial NADH dehydrogenase subunit 1, 2, 3, 4, 4L, 5 and 6 genes from Iranian patients with Leber’s hereditary optic neuropathy (LHON)

Leber’s hereditary optic neuropathy (LHON) is an optic nerve dysfunction resulting from mutations in mitochondrial DNA (mtDNA), which is transmitted in a maternal pattern of inheritance. It is caused by three primary point mutations: G11778A, G3460A and T14484C; in the mitochondrial genome. These mutations are sufficient to induce the disease, accounting for the majority of LHON cases, and affect genes that encode for the different subunits of mitochondrial complexes I and III of the mitochondrial respiratory chain. Other mutations are secondary mutations associated with the primary mutations. The purpose of this study was to determine MT-ND variations in Iranian patients with LHON. In order to determine the prevalence and distribution of mitochondrial mutations in the LHON patients, their DNA was studied using PCR and DNA sequencing analysis. Sequencing of MT-ND genes from 35 LHON patients revealed a total of 44 nucleotide variations, in which fifteen novel variations—A14020G, A13663G, C10399T, C4932A, C3893G, C10557A, C12012A, C13934T, G4596A, T12851A, T4539A, T4941A, T13255A, T14353C and del A 4513—were observed in 27 LHON patients. However, eight patients showed no variation in the ND genes. These mutations contribute to the current database of mtDNA polymorphisms in LHON patients and may facilitate the definition of disease-related mutations in human mtDNA. This research may help to understand the disease mechanism and open up new diagnostic opportunities for LHON.     

Kinetics of cell growth and cyclosporin A production by Tolypocladium inflatum when scaling up from shake flask to bioreactor

The kinetics of cell growth and Cyclosporin A (Cyc A) production by Tolypocladium inflatum were studied in shake flasks and bioreactors under controlled and uncontrolled pH conditions. In the case of the shake flask, the production time was extended to 226 h and the maximal antibiotic concentration was 76 mg/l. When scaling up the cultivation process to a bioreactor level, the production time was reduced to only 70 h with a significant increase in both the cell growth and the antibiotic production. The maximal dry cell weights in the case of the controlled pH and uncontrolled pH cultures in the bioreactor were 22.4 g/l and 14.2 g/l, respectively. The corresponding maximal dry cell weight values did not exceed 7.25 g/l with the shake flask cultures. The maximal values for Cyc A production were 144.72 and 131.4 mg/l for the controlled and uncontrolled pH cultures, respectively. It is also worth noting that a significant reduction was observed in both the dry cell mass and the antibiotic concentration after the Cyc A production phase, whereas the highest rate of antibiotic degradation was observed in the stirred tank bioreactor with an uncontrolled pH. Morphological characterization of the micromorphological cell growth (mycelial/pellet forms) was also performed during cultivation in the bioreactor.     

Nicotine improves ethanol-induced memory impairment: The role of dorsal hippocampal NMDA receptors

AimsThe current study was undertaken to determine the role of dorsal hippocampal N-methyl-d-aspartate (NMDA) receptors in nicotine's effect on impairment of memory by ethanol.Main methodsAdult male mice were cannulated in the CA1 regions of dorsal hippocampi and trained on a passive avoidance learning task for memory assessment.Key findingsWe found that pre-training intraperitoneal (i.p.) administration of ethanol (0.5 and 1 g/kg) decreased memory retrieval when tested 24 h later. Pre-test administration of ethanol reversed the decrease in inhibitory avoidance response induced by pre-training ethanol. Similar to ethanol, pre-test administration of nicotine (0.125–0.75 mg/kg, s.c.) prevented impairment of memory by pre-training ethanol. In the animals that received ethanol (1 g/kg, i.p) before training and tested following intra-CA1 administration of different doses of NMDA (0.0005–0.005 µg/mouse), no significant change was observed in the retrieval latencies. Co-administration of the same doses of NMDA with an ineffective dose of nicotine (0.125 mg/kg, s.c.) significantly improved the memory retrieval and mimicked the effects of pre-test administration of a higher dose of nicotine. Pre-test intra-CA1 microinjection of MK-801 (0.25–1 µg/mouse), which had no effect alone, in combination with an effective dose of nicotine (0.75 mg/kg, s.c.) prevented the improving effect of nicotine on memory impaired by pre-training ethanol. Moreover, intra-CA1 microinjection of MK-801 reversed the NMDA-induced potentiation of the nicotine response.SignificanceThe results suggest the importance of NMDA glutamate system(s) in the CA1 regions of dorsal hippocampus for improving the effect of nicotine on the ethanol-induced amnesia.     

Compatibility of Lecanicillium longisporum with acetamipride and imidaclopride under laboratory conditions

Lecanicillium longisporum is one of the facultative insect pathogens with significant host range and host specificity. The conidia survival may be affected by environmental factors or by bio-pesticides and chemical products used to protect crop plants. In this research, the compatibility of the mentioned fungi with acetamipride and imidaclopride and the effect of these insecticides on conidial germination and vegetative growth were studied. The formulations of insecticides were tested in three concentrations (mean concentration (MC), half MC and twice the MC). The study was conducted in completely randomised design (CRD) with four replications. The results indicated that acetamipride and imidaclopride in half MC were compatible with L. longisporum (isolate LRC195). However, based on the results, imidacloprid compared to acetamipride is adaptable with L. longisporum. These insecticides could be used simultaneously in low concentration with this entomopathogenic fungus in integrated pest management.     

Application of mesenchymal stem cells in regenerative medicine: A new approach in modern medical science

Mesenchymal Stem Cells (MSCs) are non-hematopoietic and multipotent stem cells, which have been considered in regenerative medicine. These cells are easily separated from different sources, such as bone marrow (BM), umbilical cord (UC), adipose tissue (AT), and etc. MSCs have the differentiation capability into chondrocytes, osteocytes, and adipocytes; This differentiation potential along with the paracrine properties have made them a key choice for tissue repair. MSCs also have various advantages over other stem cells, which is why they have been extensively studied in recent years. The effectiveness of MSCs-based therapies depend on several factors, including differentiation status at the time of use, concentration per injection, delivery method, the used vehicle, and the nature and extent of the damage. Although, MSCs have emerged promising sources for regenerative medicine, there are potential risks regarding their safety in their clinical use, including tumorigenesis, lack of availability, aging, and sensitivity to toxic environments. In this study, we aimed to discuss how MSCs may be useful in treating defects and diseases. To this aim, we will review recent advances of MSCs action mechanisms in regenerative medicine, as well as the most recent clinical trials. We will also have a brief overview of MSCs resources, differences between their sources, culture conditions, extraction methods, and clinical application of MSCs in various fields of regenerative medicine.     

Psychrophilic α-amylase from Aeromonas veronii NS07 isolated from farm soils

Among 120 isolates examined in this study, three isolates were selected for amylase production on starch agar plates following incubation at 10 °C. Identification by 16SrRNA on selected bacterium disclosed the highest similarity for protean regions of this gene as Aeromonas veronii NS07. A 63 kDa psychrophilic amylase enzyme from NS07 strain was purified by two-steps chromatography. The enzyme had the highest specific activity at pH 4 and was active at the range of temperatures from 0 to 50 °C, although the optimum temperature for enzyme activity was found at 10 °C. Analysis of the N-terminal amino acid sequencing disclosed 20 amino acids from purified amylase which had no similarity with other known α-amylases, indicating that the presented enzyme was novel. Amylase activity was enhanced in relation to optimum activity with the presence of sodium sulphate (161%), MnCl₂ (298%), CaCl₂ (175%), FeCl₂ (182%), MgCl₂ (237%), ZnCl₂ (169%), NiCl₂ (139%), NaCl (158%), each at 5 mM, while EDTA, phenylmethane sulphonylfluoride (PMSF) (3 mM), urea (8 M) and SDS (1%) inhibited the enzyme up to 5%, 2%, 80% and 18%, respectively. NS07 strain seems to be suitable as biocatalyst for practical use in liquefaction of starch at low temperatures, detergent and textile industries.     

Nickel (II) complexes of naphthaquinone thiosemicarbazone and semicarbazone: synthesis, structure, spectroscopy, and biological activity

Ni(II) complexes of ortho-naphthaquinone thiosemicarbazone and semicarbazone were synthesized and spectroscopically characterized. The X-ray crystal structure of both the complexes describe a distorted octahedral coordination with two tridentate mono-deprotonated ligands. In vitro anticancer studies on MCF-7 human breast cancer cells reveal that the semicarbazone derivative along with its nickel complex is more active in the inhibition of cell proliferation than the thiosemicarbazone analogue.