301 research outputs found

    Fine needle aspiration cytology of hepatic metastases of neuroendocrine tumors: A 20‐year retrospective, single institutional study

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    Background Fine needle aspiration (FNA) is considered an excellent technique for documenting metastatic neuroendocrine tumors (NETs). This study aims to evaluate the accuracy of FNA in diagnosing metastatic NETs to the liver and determining the grade and origin of these metastases. Methods Our laboratory information system was searched from 1997 to 2016 to identify all cases of metastatic NETs to the liver that were sampled by FNA. The cytopathology and surgical pathology reports as well as the patients' electronic medical records were reviewed. The cytohistologic type and grade of the metastatic NETs, as well as the site of the patient's primary were recorded. Results High‐grade NETs, including small cell and poorly differentiated neuroendocrine carcinomas, constituted 62% (167/271) of the cases, while low‐grade NETs, including well differentiated NET (grade1 and grade 2), pheochromocytomas, paragangliomas, and carcinoid tumors of lung, constituted 38% (104/271) of cases. The most common diagnosis was metastatic small cell carcinoma accounting for 45% (122/271) of cases. The most common primary sites were lung (44%; 119/271) followed by pancreas (19%; 51/271). The FNA diagnosis was confirmed by histopathology in 121 cases that had a concurrent biopsies or resection specimens. Conclusions FNA is an accurate method for diagnosing metastatic NETs to the liver. There were significantly more high‐grade (62%) than low‐grade (38%) metastatic NETs to the liver. In our practice, lung (44%) and pancreas (19%) were the most common primary sites of metastatic NETs involving the liver. In 16% of the cases, a primary site could not be established

    Numerical assessments of a nonintrusive surrogate model based on recurrent neural networks and proper orthogonal decomposition: Rayleigh Benard convection

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    Recent developments in diagnostic and computing technologies offer to leverage numerous forms of nonintrusive modeling approaches from data where machine learning can be used to build computationally cheap and accurate surrogate models. To this end, we present a nonlinear proper orthogonal decomposition (POD) framework, denoted as NLPOD, to forge a nonintrusive reduced-order model for the Boussinesq equations. In our NLPOD approach, we first employ the POD procedure to obtain a set of global modes to build a linear-fit latent space and utilize an autoencoder network to compress the projection of this latent space through a nonlinear unsupervised mapping of POD coefficients. Then, long short-term memory (LSTM) neural network architecture is utilized to discover temporal patterns in this low-rank manifold. While performing a detailed sensitivity analysis for hyperparameters of the LSTM model, the trade-off between accuracy and efficiency is systematically analyzed for solving a canonical Rayleigh-Benard convection system

    Toward advanced modular drug and gene delivery system

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    In chapter two, the development of new a nanoparticulate carrier system for gene delivery was described. The new nanocarrier consists of a blend matrix formed by a poly (lactic-eo-glycolic acid) (PLGA) and Poly(ethylene glycol) bis (3-aminopropyl) terminated (also known as JeffamineTM). Nanopartic1es were formulated based on a 50:50 weight ratio of PLGA:Jeffamine using a modified emulsification-solvent diffusion technique. The potential of these blended matrix nanoparticles for encapsulation efficiency of Calf Thymus DNA and release profile were also studied. The achieved encapsulation efficiency of Calf Thymus DNA was approximately 84% for 0.4% theoretical loading with regard to total amount of PLGA. The PLGA: Jeffamine blended nanoparticles provided continuous and controlled release of Calf Thymus DNA. The PLGA:Jeffamine nanopartic1es were also coated with PLGA-PEGMA&75and PDMAEMA-PEGMA block copolymers using a simple physical adsorption method. After surface coating of the nanoparticles, zeta potential value showed significant reduction of surface charges from -38 mV to near zero value, while TEM micrographs showed a well defined core-shell nanoparticle. In chapter three, A facile route to biocompatible poly (lactic acid-coglycolic acid)-co-poly (ethyleneglycol methacrylate) (PLGA-PEGMA) block co-polymers was described utilising a combination of ring-opening polymerisation (ROP) and Radical Addition Fragmentation Transfer (RAFT) methods. A series of PLGA-PEGMA polymers varying in comonomer content and block length were synthesised with low polydispersities. All the block co-polymers formed micelles in aqueous solution as shown by dynamic light scattering, while critical micelle concentrations were found to be in the micromolar range. The polymer micelles were able to encapsulate model drugs(carboxyfluorescein and fluorescein isothiocyanate) and selected copolymer micelles incubated with 3T3 fibroblasts as a model cell line were rapidly taken up as indicated by fluorescence microscopy assays. The combination of the polymer chemistries opens the way to highly flexible syntheses of micellar drug carrier systems. In chapter four, multifunctional and modular block co-polymers prepared from biocompatible monomers and linked by a bioreducible disulphide linkage have been prepared using a combination of ring-opening and atom-transfer radical polymerizations (ATRP). The presence of terminal functionality via ATRP allowed cell-targeting folic acid groups to be attached in a controllable manner, while the block co-polymer architecture enabled well-defined nanopartic1es to be prepared by a water-oil-water double emulsion procedure to encapsulate DNA with high efficiency. Gene delivery assays in a Calu-3 cell line indicated specific folatereceptor-mediated uptake of the nanoparticles, and triggered release of the DNA payload via cleavage of the disulfide link resulted in enhanced transgene expression compared to non-bioreducible analogues. These materials offer a promising and generic means to deliver a wide variety of therapeutic payloads to cells in a selective and tuneable way

    Toward advanced modular drug and gene delivery system

    Get PDF
    In chapter two, the development of new a nanoparticulate carrier system for gene delivery was described. The new nanocarrier consists of a blend matrix formed by a poly (lactic-eo-glycolic acid) (PLGA) and Poly(ethylene glycol) bis (3-aminopropyl) terminated (also known as JeffamineTM). Nanopartic1es were formulated based on a 50:50 weight ratio of PLGA:Jeffamine using a modified emulsification-solvent diffusion technique. The potential of these blended matrix nanoparticles for encapsulation efficiency of Calf Thymus DNA and release profile were also studied. The achieved encapsulation efficiency of Calf Thymus DNA was approximately 84% for 0.4% theoretical loading with regard to total amount of PLGA. The PLGA: Jeffamine blended nanoparticles provided continuous and controlled release of Calf Thymus DNA. The PLGA:Jeffamine nanopartic1es were also coated with PLGA-PEGMA&75and PDMAEMA-PEGMA block copolymers using a simple physical adsorption method. After surface coating of the nanoparticles, zeta potential value showed significant reduction of surface charges from -38 mV to near zero value, while TEM micrographs showed a well defined core-shell nanoparticle. In chapter three, A facile route to biocompatible poly (lactic acid-coglycolic acid)-co-poly (ethyleneglycol methacrylate) (PLGA-PEGMA) block co-polymers was described utilising a combination of ring-opening polymerisation (ROP) and Radical Addition Fragmentation Transfer (RAFT) methods. A series of PLGA-PEGMA polymers varying in comonomer content and block length were synthesised with low polydispersities. All the block co-polymers formed micelles in aqueous solution as shown by dynamic light scattering, while critical micelle concentrations were found to be in the micromolar range. The polymer micelles were able to encapsulate model drugs(carboxyfluorescein and fluorescein isothiocyanate) and selected copolymer micelles incubated with 3T3 fibroblasts as a model cell line were rapidly taken up as indicated by fluorescence microscopy assays. The combination of the polymer chemistries opens the way to highly flexible syntheses of micellar drug carrier systems. In chapter four, multifunctional and modular block co-polymers prepared from biocompatible monomers and linked by a bioreducible disulphide linkage have been prepared using a combination of ring-opening and atom-transfer radical polymerizations (ATRP). The presence of terminal functionality via ATRP allowed cell-targeting folic acid groups to be attached in a controllable manner, while the block co-polymer architecture enabled well-defined nanopartic1es to be prepared by a water-oil-water double emulsion procedure to encapsulate DNA with high efficiency. Gene delivery assays in a Calu-3 cell line indicated specific folatereceptor-mediated uptake of the nanoparticles, and triggered release of the DNA payload via cleavage of the disulfide link resulted in enhanced transgene expression compared to non-bioreducible analogues. These materials offer a promising and generic means to deliver a wide variety of therapeutic payloads to cells in a selective and tuneable way

    Risk factors of Gestational Diabetes Mellitus Among Saudi Women

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    Abstract:Objective: The aim of this study was to identify the main risk factors of Gestational Diabetes Mellitus among Saudi women. Methodology: This is a case control laboratory-based study conducted in Wadi Al Dawasir City in Saudi Arabia.600 pregnant women as follows; 300 screened pregnant women as the study group and 300 non screened pregnant women as the control group.Selection Criteria for the screened group: Should be booked at 28 weeks or before that, not known to be diabetic before pregnancy or diagnosed as cases of GDM before 24 weeks. Selection Criteria for the non-screened group: They were not diagnosed before pregnancy as cases of DM or diagnosed during pregnancy as cases of GDM.Screening for GDM: Screening for GDM was a routine using loading dose glucose (LDG) or glucose challenge test (GCT) between 24-28 weeks gestation according to the hospitals protocol. The pregnant women were classified into high risk or low risk according to the following characteristics  Results: Risk factors in the screened mothers with positive LDG result was: family history was identified in 56.1% (23/41) of mothers and it was absent in 43.8% (18/41). The next main risk factor among the mothers with positive LDG results was a history of baby weight 4 kg or more and was found in 9.76% (4/41) followed by history of intrauterine fetal death that was detected in 7.32% (3/41). Only one mother 2.44% (1/41) had past history of gestational diabetes mellitus similar to mothers with history of babies with congenital malformation that was detected in 2.44% (1/41) also. Family history was the main risk factor among mothers with positive LDG results as it was found in 56.1%. Within the 20 mothers with significant oral glucose tolerance test (OGTT) results, 80% (16/20) had risk factors and 20% (4/20) had no risk factors. Conclusion: Identifying of risk factors is important for screening for GDM but even women with low risk and no risk factors should be screened for GDM
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