703 research outputs found
Trophoblast 'pseudo-tumorigenesis': Significance and contributory factors
Trophoblast cells of the human placenta proliferate, migrate, and invade the pregnant uterus and its vasculature in order to nourish the developing fetus, in a way that is imitated by malignant tumors. Many similarities exist between embryo implantation and the growth of cancer cells. We begin this article by reviewing decades of studies that have helped unearth the mechanisms that contribute to the tumor-like phenotype of human trophoblast cells. Interestingly, these attributes are only transient in nature, with stringent spatial and temporal confines. The importance of intrinsic molecular controls that effectively circumscribe the extent and duration of trophoblast incursion, becomes increasingly evident in abnormal pregnancies that are characterized by aberrant trophoblast proliferation/invasion. We summarize and discuss the significance of abnormalities in these regulatory mechanisms, and finally, speculate about the use of human trophoblastic cells as model systems for the study of a variety of cellular processes. While on one hand, human placental cells are bestowed with a capacity to proliferate indefinitely and invade extensively, on the other, these cells are also replete with mechanisms to regulate these tumor-like attributes and eventually progress to a senescent apoptotic state. This is therefore, a 'well-behaved' tumor. The comparison in the present review is between the invasive cytotrophoblastic cell type and the tumor cell type
Mean values of multiplicative functions over function fields
We discuss the mean values of multiplicative functions over function fields. In particular, we adapt the authors’ new proof of Halász’s theorem on mean values to this simpler setting. Several of the technical difficulties that arise over the integers disappear in the function field setting, which helps bring out more clearly the main ideas of the proofs over number fields. We also obtain Lipschitz estimates showing the slow variation of mean values of multiplicative functions over function fields, which display some features that are not present in the integer situation
Medical Image Segmentation Using Multifractal Analysis
Image segmentation plays a key role in image analysis processes. The operations performed on a segmented image tend to affect it differently than if they were performed on the original image; therefore, segmenting an image can show radically different results from the original image and successfully doing so can yield features and other important information about the image. Proper image analysis is of high importance to the medical community as accurately classifying different conditions and diseases can be facilitated with excellent patient imaging. Multifractal analysis can be leveraged for performing texture classification and image segmentation. In this paper, we propose fusion-based algorithms utilizing multifractal analysis for medical image segmentation. We use two specific multifractal masks: square and quincunx. Our techniques show new insights by using methods such as histogram decomposition in conjunction with new techniques, such as fusion. By fusing different slope images, we can extract more features thus making our proposed algorithms more robust and accurate than traditional multifractal analysis techniques. These methods are further capable of reliably segmenting medical images by implementing multifractal analysis techniques in coordination with methods such as gaussian blurring and morphological operations. The resulting image can then be easily analyzed by medical professionals for diagnosing medical conditions. The outcomes show that the proposed algorithms extract dominant features that are more encompassing and powerful than classical techniques
Investigation on physical and mechanical behaviour of A356 - x wt. % SiC/Gr hybrid composites
The experiments were planned to fabricate an A356 as a matrix material with 3, 6, 9, 12 wt. % of SiC and 3 wt. % of Gr as reinforcements to cast the hybrid composites at optimal process variable conditions using squeeze casting technique. Further T6 heat treated casted samples are prepared for testing as per standard procedure to record the responses like density, porosity, hardness, ultimate tensile strength, and percentage elongation respectively. There is a gradual increment in density because of adding an optimal level of up to 9 wt. % of SiC and 3 wt. % of Gr strengthening particles available in the A356 matrix and the porosity present in the sample diminishes, which in turn increases the hardness
The third moment of quadratic Dirichlet L-functions
We study the third moment of quadratic Dirichlet L-functions, obtaining an
error term of size .Comment: 27 pages. v2: modified a remark on p.
A Voxel-Based Monte Carlo Model of Drug Release from Bulk Eroding Nanoparticles
The use of polymeric nanoparticles as drug delivery devices is becoming increasingly prevalent in a variety of therapeutic applications. Despite their widespread clinical use, the factors influencing the release profiles of nanoparticle-encapsulated drugs are still not quantitatively understood. We present here a new, semi-empirical model of drug release from polymeric nanoparticles using a formulation of dexamethasone encapsulated within poly(lactic-co-glycolic acid) to set model parameters. We introduce a three-dimensional voxel-based framework for Monte Carlo simulations that enables direct investigation of the entire spherical nanoparticle during particle degradation and drug release. Due to implementation of this model at the nanoscale, we utilize assumptions that simplify the model while still allowing multi-phase drug release to be simulated with good correlation to experimental results. In the future, emerging mechanistic understandings of nanoparticle drug release may be integrated into this simulation framework to increase predictive power.National Institutes of Health (U.S.) (GM57073
Assessment of the functional outcome of multiple discs prolapses treated with discectomy and surgical stabilization in tertiary care hospital in Salem district
Background: Low back pain affect up to 80% of people in the modern world at some point in their lives, creating high rates of activity limitation, work absence, impaired quality of life, and the need for medical care. To assess the functional outcome of patients with multiple discs prolapses treated with discectomy and surgical stabilization.Methods: A longitudinal study was conducted in the orthopedics department of Vinayaka missions Kirupananda Variyar medical college, Salem for two years between August 2019 and July 2020. A total of 30 patients presenting with lumbar disc herniation with radiculopathy and neurological deficits were included in the study. The diagnosis was confirmed by doing an X-ray and MRI of the lumbosacral spine. Patients were followed up for 6 months and the nature of the pain was assessed post-operatively using the Japanese orthopedic association system scoring for low back pain. It ranges from 0-15. Score 0 is the worst pain and 15 is normal.Results: The mean Japanese association score for low back pain was 7.2 before the surgical procedure and it was 12 after the procedure and the difference was found to be statistically significant. Among the postoperative complications, 4 patients developed failback syndrome and 1 patient had implant failure.Conclusios: Relief of radicular pain was associated with subjective satisfaction with the surgery among our study population, as evidenced by the decrease in radicular pain and the subjective satisfaction with the operation
Hyaluronidase Coated Molecular Envelope Technology Nanoparticles Enhance Drug Absorption via the Subcutaneous Route
Parenteral chemotherapy is usually administered intravenously, although patient preference and health economics suggest the subcutaneous (sc) route could be an attractive alternative. However, due to the low aqueous solubility of hydrophobic drugs and injection volume limitations, the total amount of drug that can be administered in a single sc injection is frequently insufficient. We have developed hyaluronidase coated nanoparticles (NPs) that efficiently encapsulate such drugs, thus addressing both issues and allowing sufficient amounts of hydrophobic drug to be administered and absorbed effectively. CUDC-101, a poorly water-soluble multitargeted anticancer drug that simultaneously inhibits the receptor tyrosine kinases (RTKs) EGFR and HER2, as well as histone deacetylase (HDAC), was encapsulated in polymeric Molecular Envelope Technology (MET) NPs. The role of polymer chemistry, formulation parameters, and coating with hyaluronidase (HYD) on MET-CUDC-101 NP formulations was examined and optimized to yield high drug loading and colloidal stability, and, after freeze-drying, stable storage at room temperature for up to 90 days. The pharmacokinetic studies in healthy rats showed that plasma AUC0-24h after sc administration correlates tightly with formulation physical chemistry, specifically in vitro colloidal stability. Compared to uncoated NPs, the HYD-coating doubled the drug plasma exposure. In a murine A431 xenograft model, the coated HYD-MET-CUDC-101 NPs at a dose equivalent to 90 mg kg-1 CUDC-101 increased the survival time from 15 days (control animals treated with hyaluronidase alone) to 43 days. Polymer MET nanoparticles coated with hyaluronidase enabled the subcutaneous delivery of a hydrophobic drug with favorable therapeutic outcomes
A prospective study on adverse drug reactions reported in a tertiary referral hospital
Background: To determine the incidence of Adverse drug reactions in our hospital, to study the age wise distribution, the role of concurrent medication and the common drugs that are prone to cause adverse drug reactions and its seriousness.Methods: After getting prior approval from Institutional ethical committee a prospective study was done where in cases attending OPD, ward, ICU were studied over a year. A complete history was taken regarding drug exposure (dosage, date started, duration and interruptions in use), initiation of drug use and onset of reaction, previous adverse drug reactions, improvement after decrease in dosage, disease states predisposing to eruptions, previous family and personal history of skin disease, environmental and occupational exposure to chemicals. Relevant laboratory test such as blood investigations, liver and renal function tests are carried out and results were analysed statistically by SPSS version 21 and interpretations done based on the results.Results: Incidence of ADR among OPD =0.18, IPD=1.98, OPD+IPD=0.39 /1000cases.The highest incidence of Adverse drug reactions were found among the age group of 30-39 years (27.45%), 40-49 years (23.53%), with the highest among antibiotic group of drugs (35.29%) involving a maximum duration of 2-7 days. Drug reactions mostly occurred with the oral route 66.67) and most of it requiring hospitalization (47.06%), 60.78% of reactions were manifested in skin, 58.82% of patients with ADR had concomitant medications and 19.61% had Diabetes mellitus, 90% of reactions abated after drug withdrawal with regard to its outcome 94.12% of reactions recovered.Conclusions: The study suggest the adverse drug reactions commonly occur in middle age, mostly manifesting in skin with oral route of administration ,associated with concomitant medications and it requires hospitalisation with a good recovery rate with diabetes being the common comorbid disorder
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