502 research outputs found

    Phytochemical and antimicrobial studies on essential oils of some aromatic plants

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    The antimicrobial activity of the volatile constituents of five different plant essential oils, that is, Ocimum sanctum (leaves), Eucalyptus globulus (leaves), Mentha arvensis (leaves), Citrus lemon (fruit epicarp) and Citrus maxima (fruit epicarp) was evaluated in vitro against seven bacteria (Bacillus pumilus, Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Salmonella typhi), two filamentous fungi (Aspergillus niger and Aspergillus flavus) and a yeast (Candida albicans). The volatile constituents of O. sanctum, E. globulus and M. arvensis exhibited strong antimicrobial activities against test pathogenic fungi and bacteria (both gram-positive and  gram-negative). The chemical composition of essential oils determined by gas chromatograph (GC) and high performance thin layer chromatography (HPTLC) analysis consisted of eugenol (56.07%), 1, 8 cineole (17.34%) and menthol (43.45%) as the major chemical constituents in O.sanctum, E. globulus and M. arvensis, respectively. Limonene was the only major constituent present in the oil samples from C. lemon with the highest percentage (78.28%)

    Assessment of diversity and plant growth promoting attributes of rhizobia isolated from Cajanus cajan L.

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    Eight (8) strains of rhizobia from Pigeon pea (Cajanus cajan) were isolated and identified based on their physiological and biochemical characteristics using standard methods. Five (5) of the isolates (KCC1 toKCC5) were subjected to partial 16S rDNA gene sequencing for phylogenetic analysis. Genetic diversity was investigated using restriction patterns produced by amplified rDNA restriction analysis (ARDRA) and were placed into different clusters. They were identified as Ensifer sinorhizobium hence named as Ensifer spp. KCC1 to KCC4. KCC5 is placed in Ensifer fredii clade. Nodulation and nitrogen fixing abilities of the isolates were confirmed by amplification of nodC and nifH genes. All of them showed indole-3-acetic acid production and phosphate solubilization activity. Only two isolates (KCC2 and KCC5) produced siderophore on CAS medium and showed strong antagonistic effect against Fusarium udum. None of the isolates produced cyanogen. The study showed that there is a considerable homogeneity amongst C. cajan root nodule isolates and can be exploited for plant growth promotion of C. cajan with effective antagonism against F. udum.Keywords: Diversity, Ensifer (Sinorhizobium) spp., pigeon pea (Cajanus cajan

    Seizures and disturbed brain potassium dynamics in the leukodystrophy megalencephalic leukoencephalopathy with subcortical cysts

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    OBJECTIVE: Loss of function of the astrocyte-specific protein MLC1 leads to the childhood-onset leukodystrophy "megalencephalic leukoencephalopathy with subcortical cysts" (MLC). Studies on isolated cells show a role for MLC1 in astrocyte volume regulation and suggest that disturbed brain ion and water homeostasis is central to the disease. Excitability of neuronal networks is particularly sensitive to ion and water homeostasis. In line with this, reports of seizures and epilepsy in MLC patients exist. However, systematic assessment and mechanistic understanding of seizures in MLC are lacking. METHODS: We analyzed an MLC patient inventory to study occurrence of seizures in MLC. We used two distinct genetic mouse models of MLC to further study epileptiform activity and seizure threshold through wireless extracellular field potential recordings. Whole-cell patch-clamp recordings and K+-sensitive electrode recordings in mouse brain slices were used to explore the underlying mechanisms of epilepsy in MLC. RESULTS: An early onset of seizures is common in MLC. Similarly, in MLC mice, we uncovered spontaneous epileptiform brain activity and a lowered threshold for induced seizures. At the cellular level, we found that although passive and active properties of individual pyramidal neurons are unchanged, extracellular K+dynamics and neuronal network activity are abnormal in MLC mice. INTERPRETATION: Disturbed astrocyte regulation of ion and water homeostasis in MLC causes hyperexcitability of neuronal networks and seizures. These findings suggest a role for defective astrocyte volume regulation in epilepsy. Ann Neurol 2018;83:636-649

    Diabetes screening with hemoglobin A1c prior to a change in guideline recommendations: prevalence and patient characteristics

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    <p>Abstract</p> <p>Background</p> <p>In January 2010, the American Diabetes Association recommended the use of hemoglobin A1c (Hgb A1c) to screen and diagnose diabetes. This study explored the prevalence and clinical context of Hgb A1c tests done for non-diabetic primary care patients for the three years prior to the release of the new guidelines. We sought to determine the provision of tests in non-diabetic patients age 19 or over, patients age 45 and over (eligible for routine diabetes screening), the annual change in the rate of this screening test, and the patient characteristics associated with the provision of Hgb A1c screening.</p> <p>Methods</p> <p>We conducted a retrospective study using data routinely collected in Electronic Medical Records. The participants were thirteen community-based family physicians in Toronto, Ontario. We calculated the proportion of non diabetic patients who had at least one Hbg A1c done in three years. We used logistic generalized estimating equation with year treated as a continuous variable to test for a non-zero slope in yearly Hbg A1c provision. We modelled screening using multivariable logistic regression.</p> <p>Results</p> <p>There were 11,792 non-diabetic adults. Of these, 1,678 (14.2%; 95%CI 13.6%-14.9%) had at least one Hgb A1c test done; this was higher for patients 45 years of age or older (20.2%; 95% CI 19.3% - 21.2%). The proportion of non-diabetic patients with an A1c test increased from 5.2% in 2007 to 8.8% in 2009 (p < 0.0001 for presence of slope). Factors associated with significantly greater adjusted odds ratios of having the test done included increasing diastolic blood pressure, increasing fasting glucose, increasing body mass index, increasing age, as well as male gender and presence of hypertension, but not smoking status or LDL cholesterol. Patients living in the highest income quintile neighbourhoods had significantly lower odds ratios of having this test done than those in the lowest quintile (p < 0.001).</p> <p>Conclusions</p> <p>A large and increasing proportion of the non-diabetic patients we studied have had an Hgb A1c for screening prior to guidelines recommending the test for this purpose. Several risk factors for cardiovascular disease or diabetes were associated with the provision of the Hgb A1c. Early uptake of the test may represent appropriate utilization.</p

    Multilevel model to assess sources of variation in follicular growth close to the time of ovulation in women with normal fertility: a multicenter observational study

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    Mikolajczyk RT, Stanford JB, Ecochard R. Multilevel model to assess sources of variation in follicular growth close to the time of ovulation in women with normal fertility: a multicenter observational study. Reproductive Biology and Endocrinology. 2008;6(1): 61.Background: To assess the amount of variability in ovarian follicular growth rate and maximum follicular diameter related to different centers, women and cycles of the same women in a multicenter observational study of follicular growth. Methods: Secondary analysis of a prospective cohort study from eight centers in Europe. There were 533 ultrasound examinations in 282 cycles of 107 women with normal fertility. A random effects model with center, woman and cycle as hierarchical units of variation was used to analyze mean follicular diameter on days preceding ovulation. Results: Follicular growth did not differ by center. There was homogenous growth across women and cycles, and the maximum follicular diameter before ovulation varied substantially across cycles but not across women. Many (about 40%) women had small maximum follicular diameter on the day before ovulation (<19 mm). Pre-ovulatory cycle length was not related to maximum follicular diameter. Conclusion: In normal fecundity, there is a substantial variation in maximum follicular diameter from cycle to cycle based on variation in the duration of follicular development, but the variation could not be explained by different characteristics of different women. Explanation of variation in follicular growth has to be found on the cycle level

    Genomic Data Reveal Toxoplasma gondii Differentiation Mutants Are Also Impaired with Respect to Switching into a Novel Extracellular Tachyzoite State

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    Toxoplasma gondii pathogenesis includes the invasion of host cells by extracellular parasites, replication of intracellular tachyzoites, and differentiation to a latent bradyzoite stage. We present the analysis of seven novel T. gondii insertional mutants that do not undergo normal differentiation to bradyzoites. Microarray quantification of the variation in genome-wide RNA levels for each parasite line and times after induction allowed us to describe states in the normal differentiation process, to analyze mutant lines in the context of these states, and to identify genes that may have roles in initiating the transition from tachyzoite to bradyzoite. Gene expression patterns in wild-type parasites undergoing differentiation suggest a novel extracellular state within the tachyzoite stage. All mutant lines exhibit aberrant regulation of bradyzoite gene expression and notably some of the mutant lines appear to exhibit high proportions of the intracellular tachyzoite state regardless of whether they are intracellular or extracellular. In addition to the genes identified by the insertional mutagenesis screen, mixture model analysis allowed us to identify a small number of genes, in mutants, for which expression patterns could not be accounted for using the three parasite states – genes that may play a mechanistic role in switching from the tachyzoite to bradyzoite stage
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