148 research outputs found

    Brain injury expands the numbers of neural stem cells and progenitors in the SVZ by enhancing their responsiveness to EGF

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    There is an increase in the numbers of neural precursors in the SVZ (subventricular zone) after moderate ischaemic injuries, but the extent of stem cell expansion and the resultant cell regeneration is modest. Therefore our studies have focused on understanding the signals that regulate these processes towards achieving a more robust amplification of the stem/progenitor cell pool. The goal of the present study was to evaluate the role of the EGFR [EGF (epidermal growth factor) receptor] in the regenerative response of the neonatal SVZ to hypoxic/ischaemic injury. We show that injury recruits quiescent cells in the SVZ to proliferate, that they divide more rapidly and that there is increased EGFR expression on both putative stem cells and progenitors. With the amplification of the precursors in the SVZ after injury there is enhanced sensitivity to EGF, but not to FGF (fibroblast growth factor)-2. EGF-dependent SVZ precursor expansion, as measured using the neurosphere assay, is lost when the EGFR is pharmacologically inhibited, and forced expression of a constitutively active EGFR is sufficient to recapitulate the exaggerated proliferation of the neural stem/progenitors that is induced by hypoxic/ischaemic brain injury. Cumulatively, our results reveal that increased EGFR signalling precedes that increase in the abundance of the putative neural stem cells and our studies implicate the EGFR as a key regulator of the expansion of SVZ precursors in response to brain injury. Thus modulating EGFR signalling represents a potential target for therapies to enhance brain repair from endogenous neural precursors following hypoxic/ischaemic and other brain injuries

    Development of fluorescent in situ hybridisation for Cryptosporidium detection reveals zoonotic and anthrioponotic transmission of sporadic cryptosporidiosis in Sydney

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    Cryptosporidium, is the most common non-viral cause of diarrhea worldwide. Of the 5 described species that contribute to the majority of human infections, C. parvum is of major interest due to its zoonotic potential. A species-specific fluorescence in situ hybridisation probe was designed to the variable region in the small subunit of the 18S rRNA of C. parvum and labeled with Cy3. Probe specificity was validated against a panel of 7 other Cryptosporidium spp. before it was applied to 33 human faecal samples positive for cryptosporidiosis which were obtained during the period from 2006-2007. Results were compared to PCR-RFLP targeting the 18S rDNA. FISH results revealed that 19 of the 33 isolates analysed were identified as C. parvum. Correlation of PCR-RFLP and FISH was statistically significant (P < 0.05), resulting in a calculated correlation coefficient of 0.994. In this study, species identification by FISH and PCR-RFLP provided preliminary evidence to support both anthroponotic and zoonotic transmission of sporadic cases of cryptosporidiosis in the Sydney basin. In conclusion, FISH using a C. parvum-specific probe provided an alternative tool for accurate identification of zoonotic Cryptosporidium which will be applied in the future to both epidemiological and outbreak investigations

    Phenolic Content and Antimicrobial activities of Date Palm (Phoenix dactylifera L.) Fruits and Leaves

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    This study aimed to investigate total phenolic content (TPC) and antibacterial activities of different extracts recovered from Date Palm fruit and leaves using various solvents, including methanol, ethanol and water. The results showed that the highest phenolic content was found in Leaf Methanol extract, followed by Leaf Ethanol extract, and then followed by Seed Methanol extract (74.4 mg/g, 67.3 mg/g, and 64.7 mg/g respectively). Whereas, the date methanol extract had the lowest phenolic content (5 mg/g). The study was also scrutinized to find the antibacterial inhibitory property in the leaves and fruits of date palm against four bacterial species (E.coli, Staphylococcus aureus, Bacillus subtilis, and Pseudomonas aeruginosa) by using the well diffusion method and minimum inhibitory concentration (MIC). Date leaves extracts showed inhibitory effect on the growth of Staphylococcus aureus and Bacillus subtilis and resistance to Pseudomonas aeruginosa and E.coli. MIC of methanol and ethanol (70%) leaves extract were 100 mg/ml and 250mg/ml for S. aureus and B. subtilis respectively, however, all the bacteria have resistance to date fruits extracts

    X-ray Structures and Computational Studies of Two Bioactive 2-(Adamantane-1-carbonyl)-N-substituted Hydrazine-1-carbothioamides

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    Two biologically active adamantane-linked hydrazine-1-carbothioamide derivatives, namely 2-(adamantane-1-carbonyl)-N-(tert-butyl)hydrazine-1-carbothioamide) 1 and 2-(adamantane-1-carbonyl)-N-cyclohexylhydrazine-1-carbothioamide 2, have been synthesized. X-ray analysis was conducted to study the effect of the t-butyl and cyclohexyl moieties on the intermolecular interactions and conformation of the molecules in the solid state. X-ray analysis reveals that compound 1 exhibits folded conformation, whereas compound 2 adopts extended conformation. The Hirshfeld surface analysis indicates that the contributions of the major intercontacts involved in the stabilization of the crystal structures do not change much as a result of the t-butyl and cyclohexyl moieties. However, the presence and absence of these contacts is revealed by the 2D-fingerprint plots. The CLP–Pixel method was used to identify the energetically significant molecular dimers. These dimers are stabilized by different types of intermolecular interactions such as N–H···S, N–H···O, C–H···S, C–H···O, H–H bonding and C–H···π interactions. The strength of these interactions was quantified by using the QTAIM approach. The results suggest that N–H···O interaction is found to be stronger among other interactions. The in vitro assay suggests that both compounds 1 and 2 exhibit urease inhibition potential, and these compounds also display moderate antiproliferative activities. Molecular docking analysis shows the key interaction between urease enzyme and title compounds. Keywords: adamantane; hydrazine-1-carbothioamide; Hirshfeld surface; CLP–Pixel; QTAIM; molecular docking; urease inhibition; antiproliferative agents; H-H bondin

    Metagenomic Analysis of the Outdoor Dust Microbiomes: A Case Study from Abu Dhabi, UAE

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    Outdoor dust covers a shattered range of microbial agents from land over transportation, human microbial flora, which includes pathogen and commensals, and airborne from the environment. Dust aerosols are rich in bacterial communities that have a major impact on human health and living environments. In this study, outdoor samples from roadside barricades, safety walls, and fences (18 samples) were collected from Abu Dhabi, UAE and bacterial diversity was assessed through a 16S rRNA amplicon next generation sequencing approach. Clean data from HiSeq produced 1,099,892 total reads pairs for 18 samples. For all samples, taxonomic classifications were assigned to the OTUs (operational taxonomic units) representative sequence using the Ribosomal Database Project database. Analysis such as alpha diversity, beta diversity, differential species analysis, and species relative abundance were performed in the clustering of samples and a functional profile heat map was obtained from the OTUs by using bioinformatics tools. A total of 2814 OTUs were identified from those samples with a coverage of more than 99%. In the phylum, all 18 samples had most of the bacterial groups such as Actinobacteria, Proteobacteria, Firmicutes, and Bacteroidetes. Twelve samples had Propionibacteria acnes and were mainly found in RD16 and RD3. Major bacteria species such as Propionibacteria acnes, Bacillus persicus, and Staphylococcus captis were found in all samples. Most of the samples had Streptococcus mitis, Staphylococcus capitis. and Nafulsella turpanensis and Enhydrobacter aerosaccus was part of the normal microbes of the skin. Salinimicrobium sp., Bacillus alkalisediminis, and Bacillus persicus are halophilic bacteria found in sediments. The heat map clustered the samples and species in vertical and horizontal classification, which represents the relationship between the samples and bacterial diversity. The heat map for the functional profile had high properties of amino acids, carbohydrate, and cofactor and vitamin metabolisms of all bacterial species from all samples. Taken together, our analyses are very relevant from the perspective of out-door air quality, airborne diseases, and epidemics, with broader implications for health safety and monitoring

    Patients in a private hospital in India leave the emergency department against medical advice for financial reasons

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    BACKGROUND: Some reports indicate financial concerns as a factor affecting ED patients leaving the acute care setting against medical advice (AMA). In India, no person is supposed to be denied urgent care because of inability to pay. Since a large proportion of the Indian health care system is financed by out-of-pocket expenses, we investigate the role of financial constraints for ED patients at a private hospital in India in leaving AMA. METHODS: A prospective ED-based cross-sectional survey of patients leaving AMA was conducted at a private hospital in India from 1 October 2010 to 31 December 2010. Descriptive statistics and the chi-square test were used to identify associations between financial factors and the decision to leave the hospital AMA. RESULTS: Overall, 55 (3.84%) ED patients left AMA, of which 46 (84%) reported leaving because of financial restrictions. Thirty-nine (71%) respondents indicated the medical bill would represent more that 25% of their annual income. Females (19/19) were more likely to leave AMA for financial reasons compared to males (27/36, p = 0.017). Among females who signed out AMA, the decision was never made by the female herself. CONCLUSION: The number of people leaving the ED AMA in a private Indian hospital is relatively high, with most leaving for financial reasons. In most cases, women did not decide to leave the ED AMA for themselves, whereas males did. This survey suggests that steps are needed to ensure that the inability to pay does not prevent emergent care from being provided

    National inventory of emergency departments in Singapore

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    Background: Emergency departments (EDs) are the basic units of emergency care. We performed a national inventory of all Singapore EDs and describe their characteristics and capabilities. Methods: Singapore EDs accessible to the general public 24/7 were surveyed using the National ED Inventories instrument ( http://www.emnet-nedi.org). ED staff members were asked about ED characteristics with reference to calendar year 2007. Results: Fourteen EDs participated (100% response). All EDs were located in hospitals, and most (92%) were independent departments. One was a psychiatric ED; the rest were general EDs. Among general EDs, all had a contiguous layout, with medical and surgical care provided in one area. All but two EDs saw both adults and children; one ED was adult-only, and the other saw only children. Six were in the public sector and seven in private health-care institutions, with public EDs seeing the majority (78%) of ED patients. Each private ED had an annual patient census of 60,000. They received 98% of ambulances and had an inpatient admission rate of 30%. Two public EDs reported being overcapacity; no private EDs did. For both public and private EDs, availability of consultant resources in EDs was high, while technological resources varied. Conclusion: Characteristics and capabilities of Singapore EDs varied and were largely dependent on whether they are in public or private hospitals. This initial inventory establishes a benchmark to further monitor the development of emergency care in Singapore

    Derivation of Pre-X Inactivation Human Embryonic Stem Cells under Physiological Oxygen Concentrations

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    The presence of two active X chromosomes (XaXa) is a hallmark of the ground state of pluripotency specific to murine embryonic stem cells (ESCs). Human ESCs (hESCs) invariably exhibit signs of X chromosome inactivation (XCI) and are considered developmentally more advanced than their murine counterparts. We describe the establishment of XaXa hESCs derived under physiological oxygen concentrations. Using these cell lines, we demonstrate that (1) differentiation of hESCs induces random XCI in a manner similar to murine ESCs, (2) chronic exposure to atmospheric oxygen is sufficient to induce irreversible XCI with minor changes of the transcriptome, (3) the Xa exhibits heavy methylation of the XIST promoter region, and (4) XCI is associated with demethylation and transcriptional activation of XIST along with H3K27-me3 deposition across the Xi. These findings indicate that the human blastocyst contains pre-X-inactivation cells and that this state is preserved in vitro through culture under physiological oxygen.Susan WhiteheadHillel and Liliana Bachrac

    Cultured circulating tumor cells and their derived xenografts for personalized oncology

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    AbstractRecent cancer research has demonstrated the existence of circulating tumor cells (CTCs) in cancer patient's blood. Once identified, CTC biomarkers will be invaluable tools for clinical diagnosis, prognosis and treatment. In this review, we propose ex vivo culture as a rational strategy for large scale amplification of the limited numbers of CTCs from a patient sample, to derive enough CTCs for accurate and reproducible characterization of the biophysical, biochemical, gene expressional and behavioral properties of the harvested cells. Because of tumor cell heterogeneity, it is important to amplify all the CTCs in a blood sample for a comprehensive understanding of their role in cancer metastasis. By analyzing critical steps and technical issues in ex vivo CTC culture, we developed a cost-effective and reproducible protocol directly culturing whole peripheral blood mononuclear cells, relying on an assumed survival advantage in CTCs and CTC-like cells over the normal cells to amplify this specified cluster of cancer cells
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