388 research outputs found
Study of extreme point rainfall over flash flood prone regions of the Himalayan foot hills of north India
In north India flash flood normally occur in the foothill and sub-montane regions of the Himalayas during the monsoon months due to incidence of heavy fall of rain
First comparison of French and Australian OsHV-1 µvars by bath exposure
Economically devastating mortality events of farmed and wild shellfish due to infectious disease have been reported globally. Currently, one of the most significant disease threats to Pacific oyster Crassostrea gigas culture is the ostreid herpesvirus 1 (OsHV-1), in particular the emerging OsHV-1 microvariant genotypes. OsHV-1 microvariants (OsHV-1 μvars) are spreading globally, and concern is high among growers in areas unaffected by OsHV-1. No study to date has compared the relative virulence among variants. We provide the first challenge study comparing survival of naïve juvenile Pacific oysters exposed to OsHV-1 μvars from Australia (AUS μvar) and France (FRA μvar). Oysters challenged with OsHV-1 μvars had low survival (2.5% exposed toAUS μvar and 10% to FRA μvar), and high viral copy number as compared to control oysters(100% survival and no virus detected). As our study was conducted in a quarantine facility located~320 km from the ocean, we also compared the virulence of OsHV-1 μvars using artificial seawater made from either facility tap water (3782 μmol kg−1seawater total alkalinity) or purchased distilled water (2003 μmol kg−1). Although no differences in survival or viral copy number were detected in oysters exposed to seawater made using tap or distilled water, more OsHV-1 was detected in tanks containing the lower-alkalinity seawater, indicating that water quality may be important for virus transmission, as it may influence the duration of viral viability outside of the hos
Severe cholestatic jaundice after a single administration of ajmaline; a case report and review of the literature.
BACKGROUND: Ajmaline is a pharmaceutical agent now administered globally for a variety of indications, particularly investigation of suspected Brugada syndrome. There have been previous reports suggesting that repetitive use of this agent may cause severe liver injury, but little evidence exists demonstrating the same effect after only a single administration. CASE PRESENTATION: A 33-year-old man of Libyan origin with no significant past medical history underwent an ajmaline provocation test for investigation of suspected Brugada syndrome. Three weeks later, he presented with painless cholestatic jaundice which peaked in severity at eleven weeks after the test. Blood tests confirmed no evidence of autoimmune or viral liver disease, whilst imaging confirmed the absence of biliary tract obstruction. A liver biopsy demonstrated centrilobular cholestasis and focal rosetting of hepatocytes, consistent with a cholestatic drug reaction. Over the course of the next few months, he began to improve clinically and biochemically, with complete resolution by one year post-exposure. CONCLUSION: Whilst ajmaline-related hepatotoxicity was well-recognised in the era in which the drug was administered as a regular medication, clinicians should be aware that ajmaline may induce severe cholestatic jaundice even after a single dose administration
Liver Transplantation because of Acute Liver Failure due to Heme Arginate Overdose in a Patient with Acute Intermittent Porphyria
In acute attacks of acute intermittent porphyria, the mainstay of treatment is glucose and heme arginate administration. We present the case of a 58-year-old patient with acute liver failure requiring urgent liver transplantation after erroneous 6-fold overdose of heme arginate during an acute attack. As recommended in the product information, albumin and charcoal were administered and hemodiafiltration was started, which could not prevent acute liver failure, requiring super-urgent liver transplantation after 6 days. The explanted liver showed no preexisting liver cirrhosis, but signs of subacute liver injury and starting regeneration. The patient recovered within a short time. A literature review revealed four poorly documented cases of potential hepatic and/or renal toxicity of hematin or heme arginate. This is the first published case report of acute liver failure requiring super-urgent liver transplantation after accidental heme arginate overdose. The literature and recommendations in case of heme arginate overdose are summarized. Knowledge of a potentially fatal course is important for the management of future cases. If acute liver failure in case of heme arginate overdose is progressive, super-urgent liver transplantation has to be evaluated
Thermal Properties of Graphene, Carbon Nanotubes and Nanostructured Carbon Materials
Recent years witnessed a rapid growth of interest of scientific and
engineering communities to thermal properties of materials. Carbon allotropes
and derivatives occupy a unique place in terms of their ability to conduct
heat. The room-temperature thermal conductivity of carbon materials span an
extraordinary large range - of over five orders of magnitude - from the lowest
in amorphous carbons to the highest in graphene and carbon nanotubes. I review
thermal and thermoelectric properties of carbon materials focusing on recent
results for graphene, carbon nanotubes and nanostructured carbon materials with
different degrees of disorder. A special attention is given to the unusual size
dependence of heat conduction in two-dimensional crystals and, specifically, in
graphene. I also describe prospects of applications of graphene and carbon
materials for thermal management of electronics.Comment: Review Paper; 37 manuscript pages; 4 figures and 2 boxe
Malaria pigment crystals as magnetic micro-rotors: Key for high-sensitivity diagnosis
The need to develop new methods for the high-sensitivity
diagnosis of malaria has initiated a global activity in medical
and interdisciplinary sciences. Most of the diverse variety of
emerging techniques are based on research-grade instruments,
sophisticated reagent-based assays or rely on expertise. Here,
we suggest an alternative optical methodology with an easy-to-
use and cost-effective instrumentation based on unique
properties of malaria pigment reported previously and determined
quantitatively in the present study. Malaria pigment, also
called hemozoin, is an insoluble microcrystalline form of heme.
These crystallites show remarkable magnetic and optical
anisotropy distinctly from any other components of blood. As a
consequence, they can simultaneously act as magnetically driven
micro-rotors and spinning polarizers in suspensions. These
properties can gain importance not only in malaria diagnosis and
therapies, where hemozoin is considered as drug target or immune
modulator, but also in the magnetic manipulation of cells and
tissues on the microscopic scale
Phosphodiesterase 4 Inhibition Reduces Innate Immunity and Improves Isoniazid Clearance of Mycobacterium tuberculosis in the Lungs of Infected Mice
Tuberculosis (TB) caused by Mycobacterium tuberculosis (Mtb) is one of the leading infectious disease causes of morbidity and mortality worldwide. Though current antibiotic regimens can cure the disease, treatment requires at least six months of drug therapy. One reason for the long duration of therapy is that the currently available TB drugs were selected for their ability to kill replicating organisms and are less effective against subpopulations of non-replicating persistent bacilli. Evidence from in vitro models of Mtb growth and mouse infection studies suggests that host immunity may provide some of the environmental cues that drive Mtb towards non-replicating persistence. We hypothesized that selective modulation of the host immune response to modify the environmental pressure on the bacilli may result in better bacterial clearance during TB treatment. For this proof of principal study, we compared bacillary clearance from the lungs of Mtb-infected mice treated with the anti-TB drug isoniazid (INH) in the presence and absence of an immunomodulatory phosphodiesterase 4 inhibitor (PDE4i), CC-3052. The effects of CC-3052 on host global gene expression, induction of cytokines, and T cell activation in the lungs of infected mice were evaluated. We show that CC-3052 modulates the innate immune response without causing generalized immune suppression. Immune modulation combined with INH treatment improved bacillary clearance and resulted in smaller granulomas and less lung pathology, compared to treatment with INH alone. This novel strategy of combining anti-TB drugs with an immune modulating molecule, if applied appropriately to patients, may shorten the duration of TB treatment and improve clinical outcome
Mesenchymal Stromal Cells Primed with Paclitaxel Provide a New Approach for Cancer Therapy
BACKGROUND: Mesenchymal stromal cells may represent an ideal candidate to deliver anti-cancer drugs. In a previous study, we demonstrated that exposure of mouse bone marrow derived stromal cells to Doxorubicin led them to acquire anti-proliferative potential towards co-cultured haematopoietic stem cells (HSCs). We thus hypothesized whether freshly isolated human bone marrow Mesenchymal stem cells (hMSCs) and mature murine stromal cells (SR4987 line) primed in vitro with anti-cancer drugs and then localized near cancer cells, could inhibit proliferation. METHODS AND PRINCIPAL FINDINGS: Paclitaxel (PTX) was used to prime culture of hMSCs and SR4987. Incorporation of PTX into hMSCs was studied by using FICT-labelled-PTX and analyzed by FACS and confocal microscopy. Release of PTX in culture medium by PTX primed hMSCs (hMSCsPTX) was investigated by HPLC. Culture of Endothelial cells (ECs) and aorta ring assay were used to test the anti-angiogenic activity of hMSCsPTX and PTX primed SR4987(SR4987PTX), while anti-tumor activity was tested in vitro on the proliferation of different tumor cell lines and in vivo by co-transplanting hMSCsPTX and SR4987PTX with cancer cells in mice. Nevertheless, despite a loss of cells due to chemo-induced apoptosis, both hMSCs and SR4987 were able to rapidly incorporate PTX and could slowly release PTX in the culture medium in a time dependent manner. PTX primed cells acquired a potent anti-tumor and anti-angiogenic activity in vitro that was dose dependent, and demonstrable by using their conditioned medium or by co-culture assay. Finally, hMSCsPTX and SR4987PTX co-injected with human cancer cells (DU145 and U87MG) and mouse melanoma cells (B16) in immunodeficient and in syngenic mice significantly delayed tumor takes and reduced tumor growth. CONCLUSIONS: These data demonstrate, for the first time, that without any genetic manipulation, mesenchymal stromal cells can uptake and subsequently slowly release PTX. This may lead to potential new tools to increase efficacy of cancer therapy
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