Normal Molecular Weight Research Articles

Modeling interfacial tension of surfactant–hydrocarbon systems using robust tree-based machine learning algorithms

Interfacial tension (IFT) between surfactants and hydrocarbon is one of the important parameters in petroleum engineering to have a successful enhanced oil recovery (EOR) operation. Measuring IFT in the laboratory is time-consuming and costly. Since, the accurate estimation of IFT is of paramount significance, modeling with advanced intelligent techniques has been used as a proper alternative in recent years. In this study, the IFT values between surfactants and hydrocarbon were predicted using tree-based machine learning algorithms. Decision tree (DT), extra trees (ET), and gradient boosted regression trees (GBRT) were used to predict this parameter. For this purpose, 390 experimental data collected from previous studies were used to implement intelligent models. Temperature, normal alkane molecular weight, surfactant concentration, hydrophilic–lipophilic balance (HLB), and phase inversion temperature (PIT) were selected as inputs of models and independent variables. Also, the IFT between the surfactant solution and normal alkanes was selected as the output of the models and the dependent variable. Moreover, the implemented models were evaluated using statistical analyses and applied graphical methods. The results showed that DT, ET, and GBRT could predict the data with average absolute relative error values of 4.12%, 3.52%, and 2.71%, respectively. The R-squared of all implementation models is higher than 0.98, and for the best model, GBRT, it is 0.9939. Furthermore, sensitivity analysis using the Pearson approach was utilized to detect correlation coefficients of the input parameters. Based on this technique, the results of sensitivity analysis demonstrated that PIT, surfactant concentration, and HLB had the greatest effect on IFT, respectively. Finally, GBRT was statistically credited by the Leverage approach.

#6603 THE ROLE OF ANTICOAGULATION IN KIDNEY TRANSPLANTATIONS FROM UDCD WITH HIGH RESISTANCE INDEX

Abstract Background Kidney transplantations (KT) from uncontrolled donation after cardiac death (uDCD) achieve very good outcomes to short and long follow-up, but the incidence of primary non-function and venous thrombosis (VT) is very high. The resistance index (RI) after kidney transplantation increase in the VT cases and in other kidney diseases. Aims To describe the effect of prophylactic anticoagulation in KT from uDCD with RI ≥0.8 to avoid VT and its secondary effect. Method Unicentric retrospective cohorts study that included all KT from uDCD with RI ≥0.8 measured by ecodoppler in the first 72 hours post-transplantation. We compared one group, which never received anticoagulation (Group I), and a second one which received prophylactic anticoagulation (Group II). Sodic heparin was the administer anticoagulant to achieve aPTT 1.5-2 time normal range and/or low molecular weight heparin adjusted to patient's weight and renal function. Results We included 107 KT from uDCD with RI≥0.8, with 36 in Group I and 76 in Group II. In Group I the donors were younger (39 ± 12 vs 46 ± 8; p = 0.003) and there were more men donors (97.2% vs 81.7%; p = 0.032). The prevalence of VT was higher in Group I (19.4% vs 0%; p<0.001). Patients in Group II needed more red blood transfusions (19.4% vs 39.4%; p = 0.05) and had more macroscopic haematuria (5.6% vs 21.1%; p = 0.049). The competing risk analysis showed a higher probability to develop a VT in non-anticoagulation group (p = 0.00012) than anticoagulation group or other causes of primary non-function (Figure 1). Conclusion The prophylactic anticoagulation treatment in KT from uDCD with RI≥0.8 decreases the VT incidence and it is safe for a donor recipient.

Abstract 6054: Weight specific effects of hyaluronic acid on glioblastoma's energy metabolism and bio-molecular content

Abstract Glioblastoma (GBM) is one of the deadliest forms of brain cancer with inter and intra tumor heterogeneity and altered cell metabolism pathways. Developing multi-dimensional in vitro platforms can help explore different tumor micro-environments and can thus offer therapeutic opportunities. For a molecular-level understanding, non-destructive and label-free imaging techniques combined with in vitro tumor models offer discovery and automation potential for targeted studies. Here, we use the Fourier Transform Infrared (FTIR) spectroscopic imaging technique to profile biomolecular behavior of U87-MG GBM cell lines in a 2D culture in varied metabolic and tumor micro-environment conditions. As a micro-environmental cue, we chose to vary different molecular weights of hyaluronic acid (HA), a key component of brain’s extra-cellular matrix (ECM) and known to significantly influence cell-behavior. U87-MG cell lines were cultured for 72 hours in a DMEM supplemented with combinations of (i) glucose concentration: absent (0 mM), normal (5.5 mM) and elevated (25 mM) and (ii) molecular weights of 2 μg/ml HA: low (10 kDa)-LMW, medium (60 kDa)-MMW and high (500 kDa)-HMW. Fixed cells at different timepoints were imaged with FTIR and stained for HA-specific CD44 and RHAMM markers. Supernatant media was analyzed for metabolite expressions with LC/MS. FTIR study revealed that the Phosphate I/Amide II and Amide I/Amide II IR absorbance ratios were significantly influenced in the presence of 500 kDa HA. Visible differences in the phosphate (~1080 cm−1) and lipid (~2936 cm−1) intensities indicated signs of DNA breakages and changes in oxidative stress levels. Areas under the peaks representing α-helix (decrease) and β-sheet (increase) proteins revealed signs of protein denaturation in HMW HA cultures. These cultures also revealed elevated RHAMM expressions while the CD44 expression remained relatively unchanged. Metabolic profiling with LC/MS revealed an increase in metabolites like choline, histidine, and creatine, for cells cultured in the 0 mM glucose and HMW HA. Ornithine and Methionine remained relatively unaffected by the HA weight but showed some dependence on changing glucose levels. Proline and Tyrosine majorly showed HA weight-specific variations. Overall, this preliminary study has shown the impact of glucose and HA weight-specific effects on the biomolecular content and metabolic profiles of cancer cells. Most of the altered metabolite expressions seen are known to be involved in the Arginine-biosynthesis pathway which suggests a possible alteration in the same in response to environmental glucose and weight-specific HA levels. Further studies would involve the use of multi-dimensional hydrogel-cell models to assess variations in a more bio-mimetic surrounding. Highlighting altered metabolic pathways could help present novel therapeutic targets for future. Citation Format: Ashwin A. Bale, Brendan Harley, Rohit Bhargava. Weight specific effects of hyaluronic acid on glioblastoma's energy metabolism and bio-molecular content [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6054.

Nanoporous Membranes Prepared from Homogeneous Lamellar Structure Developed via Biaxial Melt‐Drawing of Ultra‐High Molecular Weight Polyethylene/Normal Molecular Weight Polyethylene Blend Films

Inside Cover: Biaxial melt-drawing of blend films composed of ultrahigh molecular weight polyethylene (UHMW-PE) and normal molecular weight polyethylene (NMW-PE) produce a unique network structure consisting of 30 nm thick homogeneous folded chain crystals. Subsequent biaxial solid-drawing produces a nanoporous structure covering a large area of the membrane surface (120 mm × 120 mm). Consistence of membrane porousness and robustness is highly desirable for various separation applications, including filtration, water purification, dialysis, and lithium-ion batteries. Further details can be found in article 2100095 by Hiroki Uehara and co-workers.

Nanoporous Membranes Prepared from Homogeneous Lamellar Structure Developed via Biaxial Melt‐Drawing of Ultra‐High Molecular Weight Polyethylene/Normal Molecular Weight Polyethylene Blend Films

AbstractBiaxial melt‐drawing of blend films composed of ultra‐high molecular weight polyethylene and normal molecular weight polyethylene produced a unique network structure consisting of 30‐nm thick homogeneous folded chain crystals. Subsequent biaxial solid‐drawing produced a nanoporous structure covering a large area of the membrane surface (120 mm × 120 mm). Effects of preparation parameters, including annealing and subsequent solid‐drawing, on resultant nanoporous morphology are also testified to achieve the desirable membrane. The higher gas permeability coefficients of the nanoporous membranes indicate that these nanopores are interconnected along the thickness direction. Despite such excellent porosity, the tensile strength reached 30 MPa, which is similar to that for the initial non‐porous film. Consistence of membrane porousness and robustness is highly desirable for various separation applications, including filtration, water purification, dialysis, and lithium‐ion batteries.

In-situ analysis for melt-drawing behavior of ultra-high molecular weight polyethylene / normal molecular weight polyethylene blend films

Blend films composed of ultrahigh molecular weight polyethylene (UHMW-PE) and normal molecular weight polyethylene (NMW-PE) with various ratios were prepared. Structural development during melt-drawing at 150 °C for these blend films were analyzed by using in-situ measurement combined with stress-strain curve and wide-angle X-ray diffraction (WAXD). With increasing NMW-PE composition, the stress value on the plateau-stress region decreases, and the slope of stress hardening due to subsequent oriented crystallization becomes gentler. Correspondingly, the in-situ measurement results clarified that blending NMW-PE restricts amorphous orientation during melt-drawing, and delays the appearance of the orthorhombic reflections. Additionally, the hexagonal crystallization, which is characteristic of melt-drawing of pure UHMW-PE, was unrecognizable for blend films. These results indicate that blending NMW-PE reduces the amount of molecular entanglements under molten state and accelerates disentanglement during melt-drawing. During cooling after such melt-drawing for blend films, arc-shaped orthorhombic reflections spreading along azimuthal direction newly appear. Morphological observation of the resultant melt-drawn films suggests that blending NMW-PE induces thin formation of the extended crystal chain (ECC), thus subsequent epitaxial crystallization of folded crystal chains (FCC) during cooling gives the homogeneous lamellae structure arranged perpendicular to drawing direction.

A two-step heat treatment of cell disruption supernatant enables efficient removal of host cell proteins before chromatographic purification of HBc particles

The thermal stability of HBc particles was systematically investigated for efficient removal of host cell proteins (HCP) by heat treatment before chromatographic step. The HBc particles were found stable up to 80°C for 30 min without any noticeable change in circular dichroism spectra, fluorescence spectra and transmission electron microscope observation. When heating was applied to precipitate the HCP in the cell disruption supernatant of HBc fermentation, the HCP removal effect was more obvious as the temperature went higher. However, a phenomenon was found beyond 70°C where the recovered HBc particles had larger than normal size and molecular weight as observed by dynamic light scattering and multi-angle laser light scattering. Analysis found that the HBc particles possess nanopores which expand with temperature. When the temperature was above 70℃, the pores were large enough for some HCP to penetrate in, but not being able to get out after cooling down. To fully utilize the thermal stability and avoid the interference of HCP entering, a two-step heat treatment strategy was designed. The supernatant was firstly heated up to 60°C for 30 min to precipitate most HCP, then another 30 min at 70°C was used to remove the rest impurities. The two-step heat treatment effectively avoided the HCP entering problem, achieving 85.8% particle recovery and 74.7% purity. With further one-step hydrophobic interaction chromatography, the purity was increased to 99.0% with overall process recovery of 77.7%, considerably higher than those reported in the literature. The same process design was applied to purify three HBc-related products, including OVA-HBc, M2e-HBc and NP-HBc. All recoveries were higher than 50% with purity greater than 97%.

A purely quantitative form of partial recessive IFN-γR2 deficiency caused by mutations of the initiation or second codon.

Mendelian susceptibility to mycobacterial disease (MSMD) is characterized by clinical disease caused by weakly virulent mycobacteria, such as environmental mycobacteria and Bacillus Calmette-Guérin vaccines, in otherwise healthy individuals. All known genetic etiologies disrupt interferon (IFN)-γ immunity. Germline bi-allelic mutations of IFNGR2 can underlie partial or complete forms of IFN-γ receptor 2 (IFN-γR2) deficiency. Patients with partial IFN-γR2 deficiency express a dysfunctional molecule on the cell surface. We studied three patients with MSMD from two unrelated kindreds from Turkey (P1, P2) and India (P3), by whole-exome sequencing. P1 and P2 are homozygous for a mutation of the initiation codon(c.1A>G) of IFNGR2, whereas P3 is homozygous for a mutation of the second codon (c.4delC). Overexpressed mutant alleles produce small amounts of full-length IFN-γR2 resulting in an impaired, but not abolished, response to IFN-γ. Moreover, SV40-fibroblasts of P1 and P2 responded weakly to IFN-γ, and Epstein Barr virus-transformed B cells had a barely detectable response to IFN-γ. Studies in patients' primary T cells and monocyte-derived macrophages yielded similar results. The residual expression of IFN-γR2 protein of normal molecular weight and function is due to the initiation of translation between the second and ninth non-AUG codons. We thus describe mutations of the first and second codons of IFNGR2, which define a new form of partial recessive IFN-γR2 deficiency. Residual levels of IFN-γ signaling were very low, accounting for the more severe clinical phenotype of these patients with residual expression levels of normally functional surface receptors than of patients with partial recessive IFN-γR2 deficiency due to surface-expressed dysfunctional receptors, whose residual levels of IFN-γ signaling were higher.

PO-445 E7107 treatment results in aberrantly spliced transcripts and protein products of P53 pathway genes

IntroductionRecent studies indicate that E7107, a spliceosome inhibitor, causes altered splicing of key genes in CLL. We evaluated the effect of E7107 on cell viability and key proteins in the p53 pathway.Material and methodsEight leukaemia/lymphoma cell lines and eight primary CLL samples (6 wild-type and 2 mutant for SF3B1) were exposed to E7107 (H3 Biomedicine) for 72 and 48 hours. Cell viability was assessed by XTT assay. To understand the effect of splicing modulation on key proteins in the p53 pathway, including p21 and MDM2, five B-cell lines were treated with E7107 for 24 hours.Results and discussionsE7107 decreased cell viability at low nanomolar concentrations in all CLL samples (mean LC50=10.5±2.0 nM; but >300 nM in two healthy PBMC controls). No correlation between drug sensitivity and SF3B1 status was observed in CLL samples (p=0.5). Six out of eight cell lines were sensitive to E7107 (mean GI50=6±1.8 nM). The GI50 values were 60.2 and 203.5 nM for the resistant HEL and HAL-01 cells, respectively. The most frequently mutated regions of the SF3B1 gene, exons 14, 15 and 16, had no mutations detected by Sanger sequencing. There was no correlation between drug sensitivity and TP53 status.Western immunoblot revealed a marked decrease of MDM2 protein level in all cell lines, accompanied by a reciprocal concentration-dependent increase in p53. The normal molecular weight p21 disappeared at higher doses of E7107, with concomitant appearance of a high molecular weight p21 isoform (~30 kDa) in TP53 wild-type cells. In addition, a lower molecular weight p53 isoform was seen in OCI-Ly3 cells treated with 50 nM E7107, likely due to alternative splicing. RT-PCR of p21 mRNA, spanning exons 3 to 4, revealed an additional longer transcript in OCI-Ly3 cells treated with E7107(50 nM, 24 hours), which sequencing confirmed was due to intron retention, predicted to result in a high molecular weight protein with an alternative c-terminal sequence. RT-PCR of MDM2 mRNA spanning exons 1 to 11 detected an altered MDM2 transcript with exons 3–10 spliced out.ConclusionE7107 treatment resulted in decreased viability of B-cell lines and primary CLL samples independently of SF3B1 status. This was associated with the production of an aberrant high molecular weight isoform of p21 due to intron retention, and a short isoform of MDM2 missing exons 3–10. Loss of normal MDM2 was accompanied by increased p53. Further investigation is needed to understand the contribution of abnormal isoforms to cell fate.

Heydeʼs Syndrome: An Integrative Disease

Heyde's syndrome is an integrative disease process that involves gastrointestinal bleeding, von-Willebrand's factor, and aortic stenosis. First described in 1958 through simple observations from an internist, its etiological description has since evolved, with clinical and bench research now indicating quite elegant pathophysiological underpinnings. We here present a case of Heyde's syndrome resulting in recurrent gastrointestinal bleeding. A 68-year-old Caucasian woman with medical comorbidities of coronary artery disease, severe aortic stenosis, hypertension, hyperlipidemia, and diabetes mellitus type 2 presented with 2 day onset of worsening chest pain and exertional dyspnea. On further inquiry, the patient also reported multiple dark bowel movements over the preceding three days. Initial laboratory values were significant for severe anemia (Hemoglobin of 7.1gm/dL). The patient was admitted for severe symptomatic anemia. A transthoracic echocardiogram revealed severe aortic stenosis (Figure 1). The patient underwent bidirectional endoscopy which demonstrated multiple arteriovenous malformations (AVMs) requiring the use of argon plasma coagulation and injection of epinephrine to achieve hemostasis. The patient was subsequently referred for expedited aortic valve replacement. It is quite infrequent that the disciplines of gastroenterology, hematology and cardiology intersect with each other in regards to forming pathophysiological basis of a disease. Heyde's syndrome represents one such example. Loss of Von-Willebrand factor (a high molecular weight protein multimer that is involved in primary hemostasis) in patients with severe aortic stenosis, is implicated in the pathogenesis. It is now believed that high-velocity flow through a stenotic aortic valve causes conformational change in the configuration of large molecular weight von-Willebrand factor, making it vulnerable to cleavage by the plasma protein ADATS13 and subsequently rendering it hemostatically inferior to the normal high molecular weight multimers. Von-Willebrand factor may have also an essential role in maintaining vascular integrity which could explain the development of angiodysplasias in patients with deficiency of this factor. Aortic valve replacement was shown to improve the levels of Von-Willebrand factor significantly and is considered the definitive treatment for Heyde's syndrome.Figure 1

Bacillus subtilis 168 levansucrase (SacB) activity affects average levan molecular weight

Levan is a fructan polymer that offers a variety of applications in the chemical, health, cosmetic and food industries. Most of the levan applications depend on levan molecular weight, which in turn depends on the source of the synthesizing enzyme and/or on reaction conditions. Here we demonstrate that in the particular case of levansucrase from Bacillus subtilis 168, enzyme concentration is also a factor defining the molecular weight levan distribution. While a bimodal distribution has been reported at the usual enzyme concentrations (1U/ml equivalent to 0.1μM levansucrase) we found that a low molecular weight normal distribution is solely obtained al high enzyme concentrations (>5U/ml equivalent to 0.5μM levansucrase) while a high normal molecular weight distribution is synthesized at low enzyme doses (0.1U/ml equivalent to 0.01μM of levansucrase).

G.P.181: Early onset and severe X-linked dilated cardiomyopathy with epilepsy, behavioral abnormalities and elevated CK due to DMD gene intron 1 splice site mutation

DMD gene mutations are responsible for the dystrophinopathies including Duchenne and Becker muscular dystrophies (DMD/BMD). Although usually associated with DMD and BMD, an almost exclusive cardiac involvement was found in rare patients carrying DMD gene mutations. We here report on a patient who developed dilated cardiomyopathy since 11years old and required heart transplantation at 14years. An older brother was also affected and transplanted. Moreover, the patient was treated by Risperidone and Lamotrigine for behavioral abnormalities and generalized epilepsy. First neuromuscular assessment at 24years did not show any muscle weakness, atrophy or hypertrophy, neither exercise intolerance nor rhabdomyolysis. CPK levels were always high (from 300 to 14000IU/L). Electromyographic examination showed myopathic pattern with normal nerve conditions. Muscle CT scan imaging was normal. As LMNA, MYH7 and LAMP2 genes analyses did not reveal any mutation, deltoid muscle biopsy was performed and revealed fiber size variation, few centralized nuclei and regenerating fibers without overt muscle fibrosis. Dystrophin protein immunohistochemical studies showed irregular staining with DYS1, MANDYS8, MANDRA1 antibodies while it was absent with DYS3 antibody. Moreover, muscle western blot studies showed highly reduced amounts of dystrophin with normal molecular weight. Subsequent DMD gene analysis did not found any genomic deletion or duplication. However, dystrophin mRNA analysis showed no amplification for the exon 1 to exon 6 fragment suggesting skipping of these exons. Finally, DMD gene sequencing using next generation technologies lead to the identification of an intron 1 splice donor site variation (c.31+4A>G). This new case further illustrates the clinical heterogeneity of dystrophinopathies. Additional molecular analyses are required to decipher the molecular basis of the predominantly cardiac and central nervous system involvement in this patient.

The Complementary Technologies to Improve Polymer Flooding Efficiency for Class II Reservoirs of Daqing Oilfield

With the amount of polymer used in oil field increases year by year and the development results turn worse, people started to pay more attention to the technologies which can improve the polymer flooding recovery of class II reservoirs. Polymer flooding efficiency can be enhanced through methods such as detail geologic analysis, project design optimization and strengthen procedure management with applying mature supporting technologies. In this paper, the necessity of improving the polymer flooding effect of class II reservoir is introduced. The technologies to develop polymer flooding efficiency are proposed. The applying results of these technologies show that meticulous reservoir simulation and deepen recognize of structure and reserve and residual oil distribution are the base of improving polymer flooding efficiency. Optimizing polymer injection design to match the oil reserve is the key part of improving polymer flooding efficiency. Deepening technology research and building workflow of different measures and adjustment technologies at different production stages are efficient ways to improve polymer flooding efficiency. Insisting on the comprehensive adjust pattern of normal molecular weight with normal molecular concentration, individual design, scale injection, profile control in time, adjust with time and strengthen procedure management are the predominant guarantee of improving polymer flooding efficiency.

Rheological measurement of molecular weight distribution of polymers

Abstract This paper has described a method to obtain the molecular weight distribution (MWD) of polymeric materials from their rheological data. The method has been developed for linear polymers with log normal molecular weight distribution. The rheological data required to obtain the molecular weight distribution are the shear storage modulus,G' (ω) , and shear loss modulus,G" (ω) , extending from the terminal zone to the plateau region. For determining the molecular weight average, the method uses the relationship between stress moduli and relaxation spectrums, with the equation that connects dynamic rheological data with molecular weight distribution, and so it is not necessary to achieve the relaxation spectrums and the molecular weight distribution is obtained directly from dynamic shear experiments and it is one of the main advantageous of the proposed method. Comparison of calculated and experimental data obtained by GPC for five polypropylene samples produced in different conditions show that model can correctly predict molecular weight distribution for these types of polymers.

Synthesis of exfoliated isotactic polypropylene/functional alkyl-triphenylphosphonium-modified clay nanocomposites by in situ polymerization

Diphenyl (4-hydroxyphenyl) hexadecyl phosphonium bromide (POH) -modified montmorillonite (POHMMT) was used to prepare a novel TiCl4/MgCl2/POHMMT compound catalyst and exfoliated iPP/POHMMT nanocomposites were prepared by the in situ intercalative polymerization of propylene with the TiCl4/MgCl2/POHMMT compound catalyst. The POH surfactants don’t change the catalytic characteristic of the Z-N catalyst and the obtained PP presents high isotacticity, normal molecular weight and molecular weight distribution. The WAXD, SAXS and TEM results demonstrate the highly exfoliated iPP/POHMMT nanocomposites were produced by the in situ polymerization with this novel catalyst, while the intercalated iPP/Na+MMT nanocomposites were produced with the TiCl4/MgCl2/Na+MMT compound catalyst. Through this approach, in situ propylene polymerization can actually take place between the silicate layers and lead not only to PP with high isotacticity and molecular weight, but also to highly exfoliated PP nanocomposites.

BRAF V600E Mutation Appears Specific for Hairy Cell Leukemia Among Low and Intermediate Grade B-Cell Lymphomas: Utility of a Real Time PCR Based Approach for Detection

Abstract 2635 BACKGROUND:Hairy cell leukemia (HCL) is a rare type of B-cell non Hodgkin lymphoma (B-NHL), which is characterized by neoplastic cells exhibiting slender cytoplasmic projections and an activated phenotype. Unlike other B-NHL, HCL lacks characteristic recurrent chromosome abnormalities and its etiology remains elusive. Recently, the BRAF V600E mutation was described to occur at a high frequency in HCL in contrast to other B-NHL, suggesting that the BRAF V600E mutation could represent a disease defining lesion and a possible therapeutic target. In this study, we determined the prevalence of the BRAF V600E mutation in a large series of low and intermediate grade B-NHL and assessed the relationship of this mutation, if any, with microsatellite instability (MSI). METHODS:DNA was extracted from various low and intermediate grade B-NHL (n=100), as defined by the 2008 World Health Organization Classification, which comprised HCL (n=10 from 6 patients), chronic lymphocytic leukemia/small lymphocytic lymphoma (n=22), mantle cell lymphoma (n=19), marginal zone lymphoma (n=22), follicular lymphoma (n=20) and lymphoplasmacytic lymphoma (n=7). Percentage of neoplastic cells was assessed by flow cytometry (n=99) or immunohistochemistry (n=1). Presence of BRAF V600E mutation was determined using a real time PCR assay using allele-specific hydrolysis (“Taqman”) probes. The detection limit of the assay was determined by diluting DNA extracted from a fresh HCL sample with normal high molecular weight DNA extracted by the same method. MSI analysis was performed using a multiplex reaction for 5 quasi monomorphic mononucleotide repeat markers (BAT-25, BAT-26, MONO-27, NR-21 and NR-24) and two highly polymorphic penta nucleotide markers (Penta C and Penta D) as sample identifiers. In the absence of normal DNA for comparison, a sample was considered MSI-H if greater than two markers showed an altered pattern, indeterminate if only two showed an alteration and MSS if no marker showed an altered allele. RESULTS:The ubiquitous occurrence and high specificity of the BRAF V600E mutation for HCL was confirmed in our series of B-NHL. The HCL samples consisted of 10 specimens from 6 patients and were the initial diagnostic specimen in 2 patients. The percentage of neoplastic cells in these samples ranged from 1% to 78.4% (median 18.2%). The BRAF V600E mutation was detected in 7 of 10 (70%) samples of HCL from 5 of 6 (83%) patients. The proportion of hairy cells was ≤5% in samples where the mutation was not detected. All 90 of the other low and intermediate grade B-NHL (>50% tumor burden) were negative for the V600E mutation. Compared to the reported sensitivity of approximately 30% tumor cells for detecting the BRAF V600E mutation by Sanger sequencing, our real time PCR assay allowed detection of the mutation in samples containing ≥9.8% tumor cells. Analysis of the HCL cases for MSI revealed that all cases had a microsatellite stable (MSS) phenotype. CONCLUSIONS:The BRAF V600E mutation appears specific for HCL among low and intermediate grade B-NHL and is not associated with microsatellite instability. These characteristics thus warrant inclusion in disease definition. Further refinements of a realtime PCR based approach for detecting the BRAF V600E mutation might be of utility in diagnosis and disease monitoring, as the neoplastic cellular yield is often limited in HCL due to underlying myelofibrosis. Disclosures:No relevant conflicts of interest to declare.

Metastable region of phase diagram: optimum parameter range for processing ultrahigh molecular weight polyethylene blends

Numerous studies suggest that two-phase morphology and thick interface are separately beneficial to the viscosity reduction and mechanical property maintainence of the matrix when normal molecular weight polymer (NMWP) is used for modification of ultrahigh molecular weight polyethylene (UHMWPE). Nevertheless, it is very difficult to obtain a UHMWPE/NMWP blend which may demonstrate both two-phase morphology and thick interface. In this work, dissipative particle dynamics simulations and Flory-Huggins theory are applied in predicting the optimum NMWP and the corresponding conditions, wherein the melt flowability of UHMWPE can be improved while its mechanical properties can also be retained. As is indicated by dissipative particle dynamics simulations and phase diagram calculated from Flory-Huggins theory, too small Flory-Huggins interaction parameter (χ) and molecular chain length of NMWP (N(NMWP)) may lead to the formation of a homogeneous phase, whereas very large interfacial tension and thin interfaces might also appear when parameters N(NMWP) and χ are too large. When these parameters are located in the metastable region of the phase diagram, however, two-phase morphology occurs and interfaces of the blends are extremely thick. Therefore, metastable state is found to be advisable for both the viscosity reduction and mechanical property improvement of the UHMWPE/NMWP blends.

Normal total and high molecular weight adiponectin levels in adults with cystic fibrosis

Cystic fibrosis related diabetes (CFRD) is an important complication of CF that increases mortality. Adiponectin, an adipokine secreted from adipose tissue, plays an important role in fatty acid and glucose metabolism. Lower total adiponectin (TA) levels have been linked to the risk of developing type 2 diabetes. However, studies show that the high molecular weight isoform (HMW), thought to be more active than TA, might be a better indicator of insulin sensitivity. Our aim was to determine the association between HMW and insulin sensitivity in CF subjects and determine if other factors might modulate its levels. Thirteen control subjects and 47 CF adults (16 with normal glucose tolerance, 16 prediabetic and 15 with CFRD) underwent an oral glucose tolerance test. Blood samples were taken at time 0, 30, 60, 90 and 120 min. Body mass index, fibrinogen, glucose and insulin, TA and HMW were measured in every subject. Regression analysis was used to determine the association between TA, HMW and glucose (fasting glucose, 2 h glucose and glucose AUC) as well as insulin (fasting insulin, insulin AUC, and Stumvoll insulin sensitivity index) parameters. TA and HMW levels were similar between CF patients and controls and were not associated to insulin sensitivity. TA was negatively associated to insulin AUC (p = 0.0108) and 2 h glucose (p = 0.0116) in controls while these relationships were either weakly negative (p = 0.0208) or weakly positive (p = 0.0105) in CF patients. Also, HMW was negatively associated to insulin (p = 0.00301) and glucose AUC (p = 0.0546) in controls whereas these associations were positive in CF patients (p = 0.0388, p = 0.0232 respectively). In conclusion, our exploratory study on HMW adiponectin demonstrated similar levels of TA and HMW between CF patients and controls and different relationships between forms of adiponectin to glucose metabolism and insulin in CF.

Effects of Ultraviolet-A and Riboflavin on the Interaction of Collagen and Proteoglycans during Corneal Cross-linking

Corneal cross-linking using riboflavin and ultraviolet-A (RFUVA) is a clinical treatment targeting the stroma in progressive keratoconus. The stroma contains keratocan, lumican, mimecan, and decorin, core proteins of major proteoglycans (PGs) that bind collagen fibrils, playing important roles in stromal transparency. Here, a model reaction system using purified, non-glycosylated PG core proteins in solution in vitro has been compared with reactions inside an intact cornea, ex vivo, revealing effects of RFUVA on interactions between PGs and collagen cross-linking. Irradiation with UVA and riboflavin cross-links collagen α and β chains into larger polymers. In addition, RFUVA cross-links PG core proteins, forming higher molecular weight polymers. When collagen type I is mixed with individual purified, non-glycosylated PG core proteins in solution in vitro and subjected to RFUVA, both keratocan and lumican strongly inhibit collagen cross-linking. However, mimecan and decorin do not inhibit but instead form cross-links with collagen, forming new high molecular weight polymers. In contrast, corneal glycosaminoglycans, keratan sulfate and chondroitin sulfate, in isolation from their core proteins, are not cross-linked by RFUVA and do not form cross-links with collagen. Significantly, when RFUVA is conducted on intact corneas ex vivo, both keratocan and lumican, in their natively glycosylated form, do form cross-links with collagen. Thus, RFUVA causes cross-linking of collagen molecules among themselves and PG core proteins among themselves, together with limited linkages between collagen and keratocan, lumican, mimecan, and decorin. RFUVA as a diagnostic tool reveals that keratocan and lumican core proteins interact with collagen very differently than do mimecan and decorin.

Dissipative Particle Dynamics and Flory−Huggins Theories for Predicting the Rheological Behavior of Ultrahigh Molecular Weight Polyethylene Blends

This work aims to experimentally and theoretically study the effects of normal molecular weight polymers (NMWP) such as high-density polyethylene, low-density polyethylene, and polypropylene as processing aids on the morphology and rheological behavior of ultrahigh molecular weight polyethylene (UHMWPE). As is shown by scanning electron microscope observations, rheological measurements, and dissipative particle dynamics simulations, formation of a lubricating phase between the UHMWPE particles is responsible for the viscosity reduction of the UHMWPE. Besides, phase diagram studies on the UHMWPE/NMWP blend suggest that the optimum composition ratio of the blends lies in their composition-sensitive region when the parameter χ and molecular weight of each component are fixed at low shear rates. Meanwhile, the optimum range of parameter χ is above but close to the corresponding binodal curve at high shear rates.