363 research outputs found
The Genus Mimosa with Special Reference Tom. Quadrivalvis L. Var. Leptocarpa (D.c.) Earnedy, a New Species Record for the Weed Flora in Malaysia*)
An exploratory floristic survey of the genus Mimosa was conducted in 1993 to ascertain species diversity and their spatial patterns of distribution in Peninsular Malaysia. A new species record of uncertain indigene, M.. quadrivalvis was recorded for the first time in restricted localities along the roadsides in Pekan Darat and Bertam, Seberang Perai, Gurun and Bedong in Kedah in addition to widely distributed and seemingly ubiquitous presence of M. invisa Mart. ex. Colla and M. pudica L. The latter two species were mostly found in open, disturbed and derelict habitats, agricultural areas and ex-mining lands. Both species exhibited largely contagious and overdispersed distribution patterns with positive peaks in pattern intensity values although regularity or underdispersed distribution patterns do manifest in certain localities. The giant mimosa, M. pigra inhabited in clustered thickets, large pockets of lands in the urban and sub-urban localities in the states of Penang, Perak, Kelantan, Kuala Lumpur and Negeri Sembilan. In other states, M. pigra was confined to a few localities in smaller patches. Except for M. quadrivalvis, the other species of Mimosa are serious weeds in the agricultural, recreational and residential and derelict areas. A key to the Mimosa species is constructed along with brief descriptions on their morphology and ecology
THE GENUS MIMOSA WITH SPECIAL REFERENCE TOM. QUADRIVALVIS L. VAR. LEPTOCARPA (D.C.) EARNEDY, A NEW SPECIES RECORD FOR THE WEED FLORA IN MALAYSIA*)
An exploratory floristic survey of the genus Mimosa was conducted in 1993 to ascertain species diversity and their spatial patterns of distribution in Peninsular Malaysia. A new species record of uncertain indigene, M.. quadrivalvis was recorded for the first time in restricted localities along the roadsides in Pekan Darat and Bertam, Seberang Perai, Gurun and Bedong in Kedah in addition to widely distributed and seemingly ubiquitous presence of M. invisa Mart. ex. Colla and M. pudica L. The latter two species were mostly found in open, disturbed and derelict habitats, agricultural areas and ex-mining lands. Both species exhibited largely contagious and overdispersed distribution patterns with positive peaks in pattern intensity values although regularity or underdispersed distribution patterns do manifest in certain localities. The giant mimosa, M. pigra inhabited in clustered thickets, large pockets of lands in the urban and sub-urban localities in the states of Penang, Perak, Kelantan, Kuala Lumpur and Negeri Sembilan. In other states, M. pigra was confined to a few localities in smaller patches. Except for M. quadrivalvis, the other species of Mimosa are serious weeds in the agricultural, recreational and residential and derelict areas. A key to the Mimosa species is constructed along with brief descriptions on their morphology and ecology.Key words: Malaysia/Weed ecology/Mimosa invisa/Mimosa pigra/Mimosa pudica/Mimosa quadrivalvis/ Weed distribution/Weed anatomy and morphology
Assessment of Allelopathic Potential of Melastoma malabathricum L. on Radish raphanus sativus L. and Barnyard Grass (Echinochloacrus-galli)
Melastoma malabathricum L. is a weedy invasive shrub in arable lands, abandoned farmlands, secondary forest openings and derelict areas in Malaysia. Some allelochemicals present in this plant extracts may, directly, prevent or promote germination when environmental conditions are conducive to growth and establishment. It may have an important role, indirectly, in determining plant community structures. The aqueous extract and methanol extracts , were assayed for the aqueous extract of fresh materials with concentrations of 0, 50,100,150 and 200 gl-1 and at aqueous of oven dried materials extract with concentrations of 40,80,120,160,and 200 gl-1 .The crude methanol extracts were prepared using extract concentrations of 10.8,14.28 ,18 and 30 gl-1 of shoot and root materials. The extracts were tested with the widely used radish seed barnyard grass seed. Radish seed germination was inhibited at concentrations ranging from 200 gl-1 in the extract aqueous of dried materials and in the methanol extract concentrations of 14.28 and 30 gl-1 .The inhibition of root and shoot growth was also observed in the Barnyard grass seed. Both species were susceptible to allelopathy by extracts isolated from shoot and root of M. malabathricum and also their rate of germination, root length and shoot length in were decreased upon the application of both type of extractions. The results from this study strongly suggest that allelopathy may be a possible mechanism controlling the timing of barnyard grass germination and seedling establishment
Human papillomavirus mediated inhibition of DNA damage sensing and repair drives skin carcinogenesis
Background: The failure to mount an effective DNA damage response to repair UV induced cyclobutane pyrimidine dimers (CPDs) results in an increased propensity to develop cutaneous squamous cell carcinoma (cSCC). High-risk patient groups, such as organ transplant recipients (OTRs) frequently exhibit field cancerization at UV exposed body sites from which multiple human papillomavirus (HPV)-associated cSCCs develop rapidly, leading to profound morbidity and increased mortality. In vitro molecular evidence indicates that HPV of genus beta-papillomavirus (β-PV) play an important role in accelerating the early stages of skin tumorigenesis. Methods: We investigated the effects of UV induced DNA damage in murine models of β-PV E6 oncoprotein driven skin tumorigenesis by crossing K14-HPV8-E6wt mice (developing skin tumors after UV treatment) with K14-CPD-photolyase animals and by generating the K14-HPV8-E6-K136N mutant mouse strain. Thymine dimers (marker for CPDs) and γH2AX (a marker for DNA double strand breaks) levels were determined in the murine skin and organotypic skin cultures of E6 expressing primary human keratinocytes after UV-irradiation by immunohistochemistry and in cell lines by In Cell Western blotting. Phosphorylation of ATR/Chk1 and ATM were assessed in cell lines and organotypic skin cultures by Western blots and immunohistochemistry. Results: Skin tumor development after UV-irradiation in K14-HPV8-E6wt mice could completely be blocked through expression of CPD-photolyase. Through quantification of thymine dimers after UV irradiation in cells expressing E6 proteins with point mutations at conserved residues we identified a critical lysine in the
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Selective delipidation of plasma HDL enhances reverse cholesterol transport in vivo
Uptake of cholesterol from peripheral cells by nascent small HDL circulating in plasma is necessary to prevent atherosclerosis. This process, termed reverse cholesterol transport, produces larger cholesterol-rich HDL that transfers its cholesterol to the liver facilitating excretion. Most HDL in plasma is cholesterol-rich. We demonstrate that treating plasma with a novel selective delipidation procedure converts large to small HDL [HDL-selectively delipidated (HDL-sdl)]. HDL-sdl contains several cholesterol-depleted species resembling small alpha, prebeta-1, and other prebeta forms. Selective delipidation markedly increases efficacy of plasma to stimulate ABCA1-mediated cholesterol transfer from monocytic cells to HDL. Plasma from African Green monkeys underwent selective HDL delipidation. The delipidated plasma was reinfused into five monkeys. Prebeta-1-like HDL had a plasma residence time of 8 +/- 6 h and was converted entirely to large alpha-HDL having residence times of 13-14 h. Small alpha-HDL was converted entirely to large alpha-HDL. These findings suggest that selective HDL delipidation activates reverse cholesterol transport, in vivo and in vitro. Treatment with delipidated plasma tended to reduce diet-induced aortic atherosclerosis in monkeys measured by intravascular ultrasound. These findings link the conversion of small to large HDL, in vivo, to improvement in atherosclerosis
Higher Postoperative Mortality and Inferior Survival After Right-Sided Liver Resection for Perihilar Cholangiocarcinoma:Left-Sided Resection is Preferred When Possible
BACKGROUND: A right- or left-sided liver resection can be considered in about half of patients with perihilar cholangiocarcinoma (pCCA), depending on tumor location and vascular involvement. This study compared postoperative mortality and long-term survival of right- versus left-sided liver resections for pCCA.METHODS: Patients who underwent major liver resection for pCCA at 25 Western centers were stratified according to the type of hepatectomy-left, extended left, right, and extended right. The primary outcomes were 90-day mortality and overall survival (OS).RESULTS: Between 2000 and 2022, 1701 patients underwent major liver resection for pCCA. The 90-day mortality was 9% after left-sided and 18% after right-sided liver resection (p < 0.001). The 90-day mortality rates were 8% (44/540) after left, 11% (29/276) after extended left, 17% (51/309) after right, and 19% (108/576) after extended right hepatectomy (p < 0.001). Median OS was 30 months (95% confidence interval [CI] 27-34) after left and 23 months (95% CI 20-25) after right liver resection (p < 0.001), and 33 months (95% CI 28-38), 27 months (95% CI 23-32), 25 months (95% CI 21-30), and 21 months (95% CI 18-24) after left, extended left, right, and extended right hepatectomy, respectively (p < 0.001). A left-sided resection was an independent favorable prognostic factor for both 90-day mortality and OS compared with right-sided resection, with similar results after excluding 90-day fatalities.CONCLUSIONS: A left or extended left hepatectomy is associated with a lower 90-day mortality and superior OS compared with an (extended) right hepatectomy for pCCA. When both a left and right liver resection are feasible, a left-sided liver resection is preferred.</p
Higher Postoperative Mortality and Inferior Survival After Right-Sided Liver Resection for Perihilar Cholangiocarcinoma:Left-Sided Resection is Preferred When Possible
BACKGROUND: A right- or left-sided liver resection can be considered in about half of patients with perihilar cholangiocarcinoma (pCCA), depending on tumor location and vascular involvement. This study compared postoperative mortality and long-term survival of right- versus left-sided liver resections for pCCA.METHODS: Patients who underwent major liver resection for pCCA at 25 Western centers were stratified according to the type of hepatectomy-left, extended left, right, and extended right. The primary outcomes were 90-day mortality and overall survival (OS).RESULTS: Between 2000 and 2022, 1701 patients underwent major liver resection for pCCA. The 90-day mortality was 9% after left-sided and 18% after right-sided liver resection (p < 0.001). The 90-day mortality rates were 8% (44/540) after left, 11% (29/276) after extended left, 17% (51/309) after right, and 19% (108/576) after extended right hepatectomy (p < 0.001). Median OS was 30 months (95% confidence interval [CI] 27-34) after left and 23 months (95% CI 20-25) after right liver resection (p < 0.001), and 33 months (95% CI 28-38), 27 months (95% CI 23-32), 25 months (95% CI 21-30), and 21 months (95% CI 18-24) after left, extended left, right, and extended right hepatectomy, respectively (p < 0.001). A left-sided resection was an independent favorable prognostic factor for both 90-day mortality and OS compared with right-sided resection, with similar results after excluding 90-day fatalities.CONCLUSIONS: A left or extended left hepatectomy is associated with a lower 90-day mortality and superior OS compared with an (extended) right hepatectomy for pCCA. When both a left and right liver resection are feasible, a left-sided liver resection is preferred.</p
Gamma-Secretase-Dependent and -Independent Effects of Presenilin1 on β-Catenin·Tcf-4 Transcriptional Activity
Presenilin1 (PS1) is a component of the γ-secretase complex mutated in cases of Familial Alzheimer's disease (FAD). PS1 is synthesized as a 50 kDa peptide subsequently processed to two 29 and 20 kDa subunits that remain associated. Processing of PS1 is inhibited by several mutations detected in FAD patients. PS1 acts as negative modulator of β-catenin·Tcf-4 transcriptional activity. In this article we show that in murine embryonic fibroblasts (MEFs) the mechanisms of action of the processed and non-processed forms of PS1 on β-catenin·Tcf-4 transcription are different. Whereas non-processed PS1 inhibits β-catenin·Tcf-4 activity through a mechanism independent of γ-secretase and associated with the interaction of this protein with plakoglobin and Tcf-4, the effect of processed PS1 is prevented by γ-secretase inhibitors, and requires its interaction with E- or N-cadherin and the generation of cytosolic terminal fragments of these two cadherins, which in turn destabilize the β-catenin transcriptional cofactor CBP. Accordingly, the two forms of PS1 interact differently with E-cadherin or β-catenin and plakoglobin: whereas processed PS1 binds E-cadherin with high affinity and β-catenin or plakoglobin weakly, the non-processed form behaves inversely. Moreover, contrarily to processed PS1, that decreases the levels of c-fos RNA, non-processed PS1 inhibits the expression c-myc, a known target of β-catenin·Tcf-4, and does not block the activity of other transcriptional factors requiring CBP. These results indicate that prevention of PS1 processing in FAD affects the mechanism of repression of the transcriptional activity dependent on β-catenin
Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis
BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London
Integrated Assessment of Heavy Metal Contamination in Sediments from a Coastal Industrial Basin, NE China
The purpose of this study is to investigate the current status of metal pollution of the sediments from urban-stream, estuary and Jinzhou Bay of the coastal industrial city, NE China. Forty surface sediment samples from river, estuary and bay and one sediment core from Jinzhou bay were collected and analyzed for heavy metal concentrations of Cu, Zn, Pb, Cd, Ni and Mn. The data reveals that there was a remarkable change in the contents of heavy metals among the sampling sediments, and all the mean values of heavy metal concentration were higher than the national guideline values of marine sediment quality of China (GB 18668-2002). This is one of the most polluted of the world’s impacted coastal systems. Both the correlation analyses and geostatistical analyses showed that Cu, Zn, Pb and Cd have a very similar spatial pattern and come from the industrial activities, and the concentration of Mn mainly caused by natural factors. The estuary is the most polluted area with extremely high potential ecological risk; however the contamination decreased with distance seaward of the river estuary. This study clearly highlights the urgent need to make great efforts to control the industrial emission and the exceptionally severe heavy metal pollution in the coastal area, and the immediate measures should be carried out to minimize the rate of contamination, and extent of future pollution problems
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