271 research outputs found
Parametric Study of Differential Absorption Lidar Systemfor Monitoring Toxic Agents in the Atmosphere
Differential absorption lidar (DIAL) techniques are advantageously used these days fordetecting and monitoring traces of toxic agents located at several kilometer in the atmosphere.A theoretical study has been carried out to simulate the performance of a multiwavelength DIALsystem. Clouds of hydrazine, unsymmetrical dimethylhydrazine (UDMH), andmonomethylhydrazine (MMH), located at various ranges up to 5 km in the atmosphere, havebeen taken as examples of the toxic agents. It has been shown that a given lidar system cannotdetect any of these agents with a specific cloud thickness if the concentration of that agent isbelow a certain value (Nmin). It has also been shown that if the concentration level of a givenagent is above a certain value (Nmax) at a particular distance, this value cannot be quantified fora given lidar system although the identity as well as the location of that agent can still bedetermined. Further, for some typical parametric conditions, the required energy levels of thelaser to detect specific concentrations of these agents at different distances have been computed.Power levels of the return signals and the SNR values from different ranges have also beencalculated for each of these toxic agents for a given value of the laser transmitter energy
A Clinical Study of Blunt Ocular Trauma in a Tertiary Care Centre.
Purpose: To analyze blunt eye injuries with respect to mode of injury, sites involved and outcome. Method: This was a retrospective study of 32 patients with blunt ocular trauma from 2010 to 2012 in a tertiary care centre. Patient data, mode and extent of injury, management and outcome was noted and analyzed. Result: The commonest age of presentation was 10-20 years (28.125%) and the commonest mode of injury was road traffic accident (28.125%). The most commonly involved structure was conjunctiva (84.375%), followed by lid and adnexa (62.5%). Anterior segment involvement included corneal epithelial defect (7 cases), hyphaema (4 cases), iritis (3 cases) and anterior dislocation of lens (1 case). Posterior segment involvement included vitreous haemorrhage (1 case) and commotio retinae (2 cases). Conclusion: This study reinforces that blunt trauma can cause any extent of damage to ocular structures and the final visual outcome is dependent on the structures injured
Human intestinal anion exchanger isoforms: expression, distribution, and membrane localization
AbstractA family of anion exchangers (AEs) including AE1, AE2 and AE3 has been described. AE3 gene has been shown to encode two alternatively spliced isoforms termed as bAE3 (brain subtype) and cAE3 (cardiac subtype). The identity of the AE(s) involved in the human intestinal NaCl absorption is not fully understood. Current studies were undertaken to identify the AE isoforms expressed in the human intestine, to define their regional and vertical axis (crypt vs. surface cells) distribution, and to elucidate their membrane localization in the epithelial cells along the entire length of the human intestine. Our studies utilizing reverse transcription (RT)-PCR with total RNA extracted from pinch biopsies from various regions of the human intestine demonstrate that AE2 and bAE3 but not AE1 or cAE3 were expressed in all the regions of the human intestine. Utilizing in situ RT-PCR, we demonstrated that the message of AE2 was expressed throughout the vertical surfaceâcrypt axis of the colon. Our Western blotting studies demonstrated that AE2 and bAE3 are localized to the basolateral but not the apical membranes of the intestinal epithelial cells from the human ileum and colon. In conclusion, our results demonstrated that in the human intestine, AE2 and bAE3, but not AE1 or cAE3, are expressed throughout the tract with the highest expression in the colon compared to the ileum and jejunum. Both the isoforms were found to be localized to the basolateral but not the apical membranes of the epithelial cells. We speculate that, in the human intestine, AE2 and bAE3 may be the âhousekeepingâ isoforms, and the apical AE, the potential candidate for chloride absorption, remains to be identified
Multilocational Evaluation of Some Selected Chickpea Nodulation Variants in India
High- (HN) and low-nodulating (LN) selections from each of the two cultivars
ICC 4948 and ZCC 5003 developed at ZCRISAT Asia Center, were evaluated
in seven experiments in five diffaent agroecological pones in India, The
objectives of this multilouzrional experiment were to validate nodulation
uzpacities of the selections in difftent environments, and to determine if the
high-nodulating seleaions were indeed high yielding. Two nonnodulczting
selections were included as refweaces to assess N, fixed by the different
selections wing the N difference method. Relative differences for nodule
number and nodule mass between the HN and LN selections within a cultivcrr
were consistent across Locations and years. The HN selections genendly yielded
higher (range 4-41 % in ICC 5003 HN and 4-1 06% in ZCC 4948 HN) than
the LN versions of the same cultiuar, but the differences wme significant
(P < 0.05) only in two of the seven experiment
Familial adenomatous polyposis is associated with a marked decrease in alkaline sphingomyelinase activity: a key factor to the unrestrained cell proliferation?
The hydrolysis of sphingomyelin generates key molecules regulating cell growth and inducing apoptosis. Data from animal cancer models support an inhibitory role for this pathway in the malignant transformation of the colonic mucosa. In the intestinal tract, a sphingomyelinase with an optimum alkaline pH has been identified. We recently found that the activity of alkaline sphingomyelinase is significantly decreased in colorectal adenocarcinomas, indicating a potential anticarcinogenic role of this enzyme. To further examine whether the reduction of sphingomyelinase is present already in the premalignant state of neoplastic transformation, we measured sphingomyelinase activities in patients with familial adenomatous polyposis (FAP) and in sporadic colorectal tubulovillous adenomas. Tissue samples were taken from adenomas and surrounding macroscopically normal mucosa from 11 FAP patients operated with ileorectal anastomosis, from three FAP patients with intact colon, from 13 patients with sporadic colorectal adenomas and from 12 controls. Activities of acid, neutral and alkaline sphingomyelinase were measured together with alkaline phosphatase. In FAP adenoma tissue, alkaline sphingomyelinase activity was reduced by 90% compared to controls (P < 0.0001), acid sphingomyelinase by 66% (P < 0.01) and neutral sphingomyelinase by 54% (P < 0.05). Similar reductions were found in the surrounding mucosa. In sporadic adenoma tissue, only alkaline sphingomyelinase was reduced significantly, by 57% (P < 0.05). Alkaline phosphatase was not changed in FAP adenomas, but decreased in the sporadic adenomas. We conclude that the markedly reduced levels of alkaline sphingomyelinase activities in FAP adenomas and in the surrounding mucosa may be a pathogenic factor that can lead to unrestrained cell proliferation and neoplastic transformation. © 1999 Cancer Research Campaig
Minnelide effectively eliminates CD133+ side population in pancreatic cancer
BACKGROUND: Pancreatic Ductal Adenocarcinoma (PDAC) is a devastating disease hallmarked by limited patient survival. Resistance to chemotherapy, a major cause of treatment failure in PDAC patients, is often attributed to Cancer Stem Cells (CSCs). Pancreatic CSCs are a small subset of quiescent cells within a tumor represented by surface markers like CD133. These cells are responsible not only for tumor recurrence, but also poor prognosis based on their âstem-likeâ characteristics. At present, conventional therapy is directed towards rapidly dividing PDAC cells and thus fails to target the CSC population. METHODS: MIA PaCa-2, S2-013 and AsPC-1 were treated with 12.5 nM triptolide (12Â T cells) for 7Â days. The surviving cells were recovered briefly in drug-free growth media and then transferred to Cancer Stem cell Media (CSM). As a control, untreated cells were also transferred to CSM media (CSM). The 12Â T and CSM cells were tested for stemness properties using RNA and protein markers. Low numbers of CSM and 12Â T cells were implanted subcutaneously in athymic nude mice to study their tumorigenic potential. 12Â T and CSM cells were sorted for CD133 expression and assayed for their colony forming ability and sphere forming ability. Invasiveness of 12Â T cells, CSM and MIA PaCa-2 were compared using Boyden chamber assays. RESULTS: Treated 12Â T cells displayed increased expression of the surface marker CD133 and the drug transporter ABCG2 compared to untreated cells (CSM cells). Both 12Â T and CSM cells formed subcutaneous tumors in mice confirming their tumor-initiating properties. When tested for invasion, 12Â T cells had increased invasiveness compared to CSM cells. CD133(+) cells in both CSM and 12Â T showed greater colony and sphere forming ability compared to CD133(â) cells from each group. Consistent with these data, when injected subcutaneously in mice, CD133(â) cells from CSM or 12Â T did not form any tumors whereas CD133(+) cells from both groups showed tumor formation at a very low cell number. Despite pre-exposure to triptolide in 12Â T CD133(+) cells, treatment of tumors formed by these cells with Minnelide, a triptolide pro-drug, showed significant tumor regression. CONCLUSION: Our results indicated that triptolide enhanced and enriched the âstemnessâ in the PDAC cell lines at a low dose of 12.5 nM, but also resulted in the regression of tumors derived from these cells. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12943-015-0470-6) contains supplementary material, which is available to authorized users
Diagnostic strategy and timing of intervention in infected necrotizing pancreatitis: an international expert survey and case vignette study
AbstractBackgroundThe optimal diagnostic strategy and timing of intervention in infected necrotizing pancreatitis is subject to debate. We performed a survey on these topics amongst a group of international expert pancreatologists.MethodsAn online survey including case vignettes was sent to 118 international pancreatologists. We evaluated the use and timing of fine needle aspiration (FNA), antibiotics, catheter drainage and (minimally invasive) necrosectomy.ResultsThe response rate was 74% (NÂ =Â 87). None of the respondents use FNA routinely, 85% selectively and 15% never. Most respondents (87%) use a step-up approach in patients with infected necrosis. Walled-off necrosis (WON) is considered a prerequisite for endoscopic drainage and percutaneous drainage by 66% and 12%, respectively. After diagnosing infected necrosis, 55% routinely postpone invasive interventions, whereas 45% proceed immediately to intervention. Lack of consensus about timing of intervention was apparent on day 14 with proven infected necrosis (58% intervention vs. 42% non-invasive) as well as on day 20 with only clinically suspected infected necrosis (59% intervention vs. 41% non-invasive).DiscussionThe step-up approach is the preferred treatment strategy in infected necrotizing pancreatitis amongst expert pancreatologists. There is no uniformity regarding the use of FNA and timing of intervention in the first 2â3 weeks of infected necrotizing pancreatitis
Synthetic Nanoparticles for Vaccines and Immunotherapy
The immune system plays a critical role in our health. No other component of human physiology plays a decisive role in as diverse an array of maladies, from deadly diseases with which we are all familiar to equally terrible esoteric conditions: HIV, malaria, pneumococcal and influenza infections; cancer; atherosclerosis; autoimmune diseases such
as lupus, diabetes, and multiple sclerosis. The importance of understanding the function of the immune system and learning how to modulate immunity to protect against or treat disease thus cannot be overstated. Fortunately, we are entering an exciting era where the
science of immunology is defining pathways for the rational manipulation of the immune system at the cellular and molecular level, and this understanding is leading to dramatic advances in the clinic that are transforming the future of medicine.1,2 These initial advances are being made primarily through biologic drugsâ recombinant proteins (especially antibodies) or patient-derived cell therapiesâ but exciting data from preclinical studies suggest that a marriage of approaches based in biotechnology with the materials science and chemistry of nanomaterials, especially nanoparticles, could enable more effective and safer immune engineering strategies. This review will examine these nanoparticle-based strategies to immune modulation in detail, and discuss the promise and outstanding challenges facing the field of immune engineering from a chemical biology/materials engineering perspectiveNational Institutes of Health (U.S.) (Grants AI111860, CA174795, CA172164, AI091693, and AI095109)United States. Department of Defense (W911NF-13-D-0001 and Awards W911NF-07-D-0004
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