Probiotic Attributes and Inhibitory Effects of Lactobacillus plantarum MYS84 against the Growth and Biofilm Formation of Pseudomonas aeruginosa

Microbiology - Manufacture of fermented foods/products, which, apart from basic nutrition, have health-promoting effects, is flourishing. Within the field of fermented foods, rapidly expanding is...     

Simple and rapid liquid chromatography method for determination of moxifloxacin in plasma

A high performance liquid chromatographic method for determination of moxifloxacin in human plasma was developed. The method involved deproteinisation of the sample with perchloric acid and analysis of the supernatant using a reversed-phase C₁₈ column (150 mm) and fluorescence detection at an excitation wavelength of 290 nm and an emission wavelength of 460 nm. The assay was specific for moxifloxacin and linear from 0.125 to 10.0 μg/ml. The relative standard deviation of intra- and inter-day assays was lower than 10%. The average recovery of moxifloxacin from plasma was 101%. Due to its simplicity, the assay can be used for pharmacokinetic studies of moxifloxacin.     

Mapping of the functional microcirculation in vital organs using contrast-enhanced in vivo video microscopy

A functional microcirculation is vital to the survival of mammalian tissues. In vivo video microscopy is often used in animal models to assess microvascular function, providing real-time observation of blood flow in normal and diseased tissues. To extend the capabilities of in vivo video microscopy, we have developed a contrast-enhanced system with postprocessing video analysis tools that permit quantitative assessment of microvascular geometry and function in vital organs and tissues. FITC-labeled dextran (250 kDa) was injected intravenously into anesthetized mice to provide intravascular fluorescence contrast with darker red blood cell (RBC) motion. Digitized video images of microcirculation in a variety of internal organs (e.g., lung, liver, ovary, and kidney) were processed using computer-based motion correction to remove background respiratory and cardiac movement. Stabilized videos were analyzed to generate a series of functional images revealing microhemodynamic parameters, such as plasma perfusion, RBC perfusion, and RBC supply rate. Fluorescence contrast revealed characteristic microvascular arrangements within different organs, and images generated from video sequences of liver metastases showed a marked reduction in the proportion of tumor vessels that were functional. Analysis of processed video sequences showed large reductions in vessel volume, length, and branch-point density, with a near doubling in vessel segment length. This study demonstrates that postprocessing of fluorescence contrast video sequences of the microcirculation can provide quantitative images useful for studies in a wide range of model systems.     

Can urine lamivudine be used to monitor antiretroviral treatment adherence?

Patient adherence to treatment is an important factor in the effectiveness of antiretroviral regimens. Adherence to treatment could be monitored by estimation of antiretroviral drugs in biological fluids. We aimed to obtain information on the quantity and duration of excretion of lamivudine in urine following oral administration of a single dose of 300 mg and to assess its suitability for adherence monitoring purposes. Spot urine samples were collected before dosing and at 4, 8, 12, 24, 28, 32, 48, 72, and 96 hours post dosing from 10 healthy subjects, and lamivudine was estimated by high-pressure liquid chromatography (HPLC). Lamivudine values were expressed as a ratio of urine creatinine. About 91% of the ingested drug was excreted by 24 hours, and the concentration thereafter in urine was very negligible. A lamivudine value of 0.035 mg/mg creatinine or less at 48 hours is suggestive of a missed dose in the last 24 hours. The study findings showed that estimation of urine lamivudine in spot specimens could be useful in monitoring patient adherence to antiretroviral treatment. However, this needs to be confirmed on a larger sample size and among patients on once-daily and twice-daily treatment regimens.     

Cloning and characterization of differentially expressed genes of internal breakdown in mango fruit (Mangifera indica)

Internal breakdown in mango fruits has become a major concern in recent years. This disorder renders the fruits unfit for human consumption. The overall loss due to this disorder is about 35-55%. Environmental and physiological factors like high temperature, humidity, respiration and low transpiration rates have been attributed to cause spongy tissue due to reduced loss of heat from fruits. Biochemical studies have shown that there is a reduction in pH, total soluble solids, ascorbic acid, total sugars and carotenoids, low reducing and non-reducing sugar contents, lower amylase and invertase activities and high acid and starch content in spongy tissue affected pulp. There are no reports on molecular studies to determine changes in gene expression in these tissues. The present study was conducted using PCR based subtractive hybridization and RNA gel blot analysis of a few selected genes. The latter showed a higher expression of catalase, ubiquitin, alcohol dehydrogenase, coproporphyrinogen oxidase and keratin associated protein. A lower expression of ribosomal gene, fructose bisphosphate aldolase and cysthathionine gamma synthase was also noticed in spongy tissue. Biochemical studies indicated a lower amylase activity and a lower content of the total and reducing sugars in spongy tissue as compared to healthy tissue. Analyses of results indicate that oxidative stress may be one of the causes for formation of spongy tissue, which affects the expression of many genes. The role of these genes in spongy tissue formation is discussed.     

Photosynthetic symmetry of sun and shade leaves of different orientations

Summary The photosynthetic responses to light of leaves irradiated on the adaxial or abaxial surfaces, were measured for plants with contrasting leaf orientations. For vertical-leaf species of open habitats (Eryngium yuccifolium and Silphium terebinthinaceum), photosynthetic rates were identical when irradiated on either surface. However, for horizontal-leaf species of open habitats (Ambrosia trifida and Solidago canadensis), light-saturated rates of photosynthesis for adaxial irradiation were 19 to 37% higher than rates for abaxial irradiation. Leaves of understory plants (Asarum canadense and Hydrophyllum canadense) were functionally symmetrical although they had horizontal orientation. Photosynthetic rates were measured at saturating CO₂, thus differences in the response to incident irradiance presumably resulted from complex interactions of light and leaf optical properties rather than from stomatal effects. Differences in absorptance (400–700 nm) among leaf surfaces were evident for horizontal-leaf species but the primary determinant of functional symmetry was leaf anatomy. Functionally symmetrical leaves had upper and lower palisade layers of equal thickness (vertical leaves of open habitats) or were composed primarily of a single layer of photosynthetic cells (horizontal leaves of understory habitats). Photosynthetic symmetry of vertical-leaf species may be an adaptation to maximize daily integrated carbon gain and water-use efficiency, whereas asymmetry of horizontal-leaf species may be an adaptation to maximize daily integrated carbon gain and photosynthetic nutrient-use efficiency.     

Hydroalcoholic Extract of Cyperus rotundus Ameliorates H2O2-Induced Human Neuronal Cell Damage via Its Anti-oxidative and Anti-apoptotic Machinery

Hydrogen peroxide (H₂O₂), a major reactive oxygen species produced during oxidative stress, has been implicated in the pathophysiology of various neurodegenerative conditions. Cyperus rotundus is a traditional medicinal herb that has recently found applications in food and confectionary industries. In the current study, the neuroprotective effects of Cyperus rotundus rhizome extract (CRE) through its antioxidant and anti-apoptotic machinery to attenuate H₂O₂-induced cell damage on human neuroblastoma SH-SY5Y cells have been explored. The results obtained demonstrate that pretreatment of cells with CRE for 2 h before administration of H₂O₂ for 24 h ameliorates the cytotoxicity induced by H₂O₂ as evidenced by MTT and LDH assays. CRE exhibited potent antioxidant activity by regulating the enzymes/proteins levels such as SOD, CAT, GPx, GR, HSP-70, Caspase-3, and Bcl-2. The pretreatment restored H₂O₂-induced cellular, nuclear, and mitochondrial morphologies as well as increased the expression of Brain derived nerve growth factor (BDNF). The anti-oxidant and anti-apoptotic potentials of the plant extract may account for its high content of phenolics, flavonoids, and other active principles. Taken together, our findings suggest that CRE might be developed as an agent for neurodegeneration prevention or therapy.     

The D153del mutation in GNB3 gene causes tissue specific signalling patterns and an abnormal renal morphology in Rge chickens

Background

The GNB3 gene is expressed in cone but not rod photoreceptors of vertebrates, where it acts as the β transducin subunit in the colour visual transduction process. A naturally occurring mutation ‘D153del’ in the GNB3 gene causes the recessively inherited blinding phenotype retinopathy globe enlarged (rge) disease in chickens. GNB3 is however also expressed in most other vertebrate tissues suggesting that the D153del mutation may exert pathological effects that outlie from eye.

Principal Findings

Recombinant studies in COS-7 cells that were transfected with normal and mutant recombinant GNB3 constructs and subjected to cycloheximide chase showed that the mutant GNB3d protein had a much shorter half life compared to normal GNB3. GNB3 codes for the Gβ3 protein subunit that, together with different Gγ and Gα subunits, activates and regulates phosphorylation cascades in different tissues. As expected, the relative levels of cGMP and cAMP secondary messengers and their activated kinases such as MAPK, AKT and GRK2 were also found to be altered significantly in a tissue specific manner in rge chickens. Histochemical analysis on kidney tissue sections, from rge homozygous affected chickens, showed the chickens had enlargement of the glomerular capsule, causing glomerulomegaly and tubulointerstitial inflammation whereas other tissues (brain, heart, liver, pancreas) were unaffected.

Significance

These findings confirm that the D153del mutation in GNB3 gene targets GNB3 protein to early degradation. Lack of GNB3 signalling causes reduced phosphorylation activity of ERK2 and AKT leading to severe pathological phenotypes such as blindness and renal abnormalities in rge chickens.