gebhart/patrepeval huggingface dataset:
Exosomes from human umbilical cord blood accelerate cutaneous wound healing through miR-21-3p-mediated promotion of angiogenesis and fibroblast function (2017)

The application of blood plasma for soft tissue wound healing is receiving much more attention recently. Exosomes are critical paracrine mediators that can be obtained from biological fluids including plasma and be able to induce regenerative effects by transferring bioactive molecules such as microRNAs (miRNAs). This study aimed to investigate the effects of exosomes from human umbilical cord blood plasma (UCB-Exos) on wound healing and to elucidate the underlying mechanism. <b>Methods:</b> UCB-Exos were isolated by ultracentrifugation and subcutaneously injected into full-thickness skin wounds in mice. The efficacy of UCB-Exos on wound healing was evaluated by measuring wound closure rates, histological analysis and immunofluorescence examinations. <i>In vitro</i>, quantitative real-time PCR (qRT-PCR) analysis was performed to detect the expression levels of a class of miRNAs that have positive roles in regulating wound healing. The scratch wound assay, transwell assay and cell counting kit-8 analysis were conducted to assess the effects of UCB-Exos on migration and proliferation of human skin fibroblasts and endothelial cells. Tube formation assay was carried out to test the impact of UCB-Exos on angiogenic tube formation ability of endothelial cells. Meanwhile, by using specific RNA inhibitors or siRNAs, the roles of the candidate miRNA and its target genes in UCB-Exos-induced regulation of function of fibroblasts and endothelial cells were assessed. <b>Results:</b> The local transplantation of UCB-Exos into mouse skin wounds resulted in accelerated re-epithelialization, reduced scar widths, and enhanced angiogenesis. <i>In vitro</i>, UCB-Exos could promote the proliferation and migration of fibroblasts, and enhance the angiogenic activities of endothelial cells. Notably, miR-21-3p was found to be highly enriched in UCB-Exos and served as a critical mediator in UCB-Exos -induced regulatory effects through inhibition of phosphatase and tensin homolog (PTEN) and sprouty homolog 1 (SPRY1). <b>Conclusion:</b> Our results suggest that UCB-Exos are important effectors of plasma activity and can be used as a novel promising strategy for soft tissue wound healing.
Photocrosslinked hyaluronic acid hydrogels: Natural, biodegradable tissue engineering scaffolds (2003)

Ideally, rationally designed tissue engineering scaffolds promote natural wound healing and regeneration. Therefore, we sought to synthesize a biomimetic hydrogel specifically designed to promote tissue repair and chose hyaluronic acid (HA; also called hyaluronan) as our initial material. Hyaluronic acid is a naturally occurring polymer associated with various cellular processes involved in wound healing, such as angiogenesis. Hyaluronic acid also presents unique advantages: it is easy to produce and modify, hydrophilic and nonadhesive, and naturally biodegradable. We prepared a range of glycidyl methacrylate-HA (GMHA) conjugates, which were subsequently photopolymerized to form crosslinked GMHA hydrogels. A range of hydrogel degradation rates was achieved as well as a corresponding, modest range of material properties (e.g., swelling, mesh size). Increased amounts of conjugated methacrylate groups corresponded with increased crosslink densities and decreased degradation rates and yet had an insignificant effect on human aortic endothelial cell cytocompatibility and proliferation. Rat subcutaneous implants of the GMHA hydrogels showed good biocompatibility, little inflammatory response, and similar levels of vascularization at the implant edge compared with those of fibrin positive controls. Therefore, these novel GMHA hydrogels are suitable for modification with adhesive peptide sequences (e.g., RGD) and use in a variety of wound-healing applications.
Isolation and characterization of a new hemoglobin derivative cross-linked between the alpha chains (lysine 99 alpha 1----lysine 99 alpha 2). (1986)

Bis(3,5-dibromosalicyl) fumarate and a number of related bifunctional reagents react preferentially with oxyhemoglobin to cross-link the beta chains within the 2,3-diphosphoglycerate-binding site. In this report we describe a new derivative cross-linked between the alpha chains which is formed specifically in the reaction with deoxyhemoglobin. X-ray crystallographic studies show that the cross-link lies between Lys-99 alpha 1 and Lys-99 alpha 2, spanning the central cavity of the tetramer. Lys-99 alpha 1 and Lys-99 alpha 2 are located within a cluster of charged residues very near the middle of the hemoglobin molecule. In oxyhemoglobin, this site is completely inaccessible to the cross-linking agent. Competition experiments with inositol hexaphosphate indicate that the compound enters the central cavity in deoxyhemoglobin through the cleft between the alpha chains. Despite the presence of the cross-link between the alpha chains, the modified hemoglobin remains highly cooperative. The Hill coefficient for HbXL99 alpha is 2.6. The oxygen affinity of the cross-linked derivative is decreased by approximately 2-fold; at pH 7.0 in the presence of 0.1 M NaCl the P50 is 13.9 mm Hg compared to 6.6 mm Hg for HbA. This difference appears to be due to relatively small changes in both KR, the association constant for binding of oxygen to the R state, and the allosteric constant L. Surprisingly, the isoelectric point of oxyHbXL99 alpha is almost identical to that of oxyHbA, whereas in the deoxy form the isoelectric point of the cross-linked derivative is decreased relative to native hemoglobin as expected due to the loss of the two positive charges of the modified amino groups. In agreement with these findings, the alkaline Bohr effect of HbXL99 alpha is decreased by more than 50%. Earlier studies argue strongly against the possibility that Lys-99 alpha is directly responsible for this large fraction of the Bohr effect in HbA. Analysis of the structure suggests that in the cross-linked derivative Glu-101 beta, which is in close proximity to Lys-99 alpha in oxyhemoglobin, becomes an acid Bohr group.
Loss of aurora A/STK15/BTAK overexpression correlates with transition of in situ to invasive ductal carcinoma of the breast. (2003)

The biological mechanisms involved in the progression of ductal carcinoma in situ (DCIS) to invasive breast cancer are not fully understood. We previously have shown that the putative oncogene Aurora-A/STK15/BTAK, encoding a centrosome-associated kinase that regulates centrosomes and chromosome segregation, is amplified in human breast cancer. In this study, 37 archival breast tissue specimens of histologically confirmed DCIS lesions with adjacent invasive carcinoma and morphologically nonmalignant mammary ducts were analyzed immunohistochemically for expression of STK15. Statistically significant differences in overexpression of STK15 was found between invasive cancer and either nonmalignant mammary ducts (P < 0.0001) or DCIS lesions (P < 0.0005). Abnormalities in centrosome size and number was detected in the samples analyzed and 56% (14 of 25) of the cases also showed aneuploidy reflected in >2 signals of chromosome 3 and 17. Our data demonstrate that STK15 overexpression correlates with centrosome anomaly and aneuploidy in DCIS, and loss of STK15 overexpression is associated with progression of in situ to ductal invasive breast carcinoma.
Mature dendritic cells pulsed with freeze–thaw cell lysates define an effective in vitro vaccine designed to elicit EBV-specific CD4+ and CD8+ T lymphocyte responses (2000)

Immunotherapy trials targeting the induction of tumor-reactive T-cell responses in cancer patients appear to hold significant promise. Because nonmutated lineage-specific antigens and mutated idiotypic antigens may be coexpressed by tumor cells, the use of autologous tumor material to promote the broadest range of antitumor T-cell specificities has significant clinical potential in cancer vaccination trials. As a model for vaccination in the cancer setting, we chose to analyze the promotion of T-cell responses against Epstein-Barr virus (EBV)-transformed B-lymphoblastoid cell line (B-LCL)–derived antigens in vitro. A series of bulk antigenic formats (freeze–thaw lysate, trifluoroacetic acid lysate, extracted membranes, affinity-purified MHC class I– and class II–presented peptides, acid-eluted peptides) prepared from EBV B-LCLs were tested for their ability to stimulate EBV B-LCL–reactive CD4+ and CD8+ T lymphocytes in vitro when pulsed onto autologous dendritic cells (DCs). DC presentation of freeze–thaw lysate material derived from (either autologous or allogeneic) EBV B-LCLs with an Mr of 10 kd or larger stimulated optimal anti-EBV B-LCL responsiveness from freshly isolated CD4+ and CD8+ peripheral blood T cells. These in vivo “memory” T-cell responses were observed only in EBV-seropositive donors. CD4+ T-cell responses to lysate-pulsed DCs were Th1 type (ie, strong interferon-γ and weak interleukin-5 responses). While CD8+ T-cell responses were also observed in interferon-γ Elispot assays and in cytotoxicity assays, these responses were of low frequency unless the DC stimulators were induced to “mature” after being fed with tumor lysates. Optimal-length, naturally processed, and MHC class I– or class II–presented tumor peptides were comparatively poorly immunogenic in this model system.
Effects of Thermal Annealing on the Li+ Intercalation Properties of V2O5·nH2O Xerogel Films (2005)

V(2)O(5) x nH(2)O xerogel films with n = 1.6, 0.6, and 0.3 have been prepared from the sol-gel route by reacting V(2)O(5) with H(2)O(2) followed by drying under ambient conditions and thermal annealing at 110 and 250 degrees C, respectively. After dehydration, V(2)O(5) crystallizes at 300-330 degrees C, as revealed by thermal gravimetric analysis and X-ray diffraction. Electrochemical characterization demonstrated that V(2)O(5) x 0.3H(2)O film exhibits the best Li(+) intercalation performance, with an initial capacity of 275 mAh/g and a stabilized capacity of 185 mAh/g under a high current density of 100 microA/cm(2) after 50 cycles. Under a low current density of 10 microA/cm(2), the capacity of this film can reach 390 mAh/g. Such an enhanced electrochemical property by thermal treatment is ascribed to the reduced water content, the retained interlayer spacing, and the dominant amorphous phase in the film.
Using pathchar to estimate Internet link characteristics (1999)

We evaluate pathchar, a tool that infers the characteristics of links along an Internet path (latency, bandwidth, queue delays). Looking at two example paths, we identify circumstances where pathchar is likely to succeed, and develop techniques to improve the accuracy of pathchar's estimates and reduce the time it takes to generate them. The most successful of these techniques is a form of adaptive data collection that reduces the number of measurements pathchar needs by more than 90% for some links.
Solid-phase synthesis of cecropin A and related peptides. (1983)

Cecropin A, a 37-residue antibacterial peptide amide, was synthesized by the solid-phase method. It was shown to be homogeneous and totally indistinguishable from natural cecropin A by chemical and physical criteria, as well as by its antibacterial activity against several Gram-positive and Gram-negative organisms. The synthetic material was also used to establish unambiguously that the carboxyl-terminal blocking group of natural cecropin A is a primary amide as tentatively proposed earlier. The role of the amino terminus of cecropin A in antibacterial activity was investigated by the synthesis of two analogs.
Antibodies That React with Predetermined Sites on Proteins (1983)

Contrary to previous predictions, relatively short synthetic peptides that mimic part of a protein sequence are routinely capable of eliciting an antiserum that reacts with the partially mimicked protein. Peptides capable of eliciting protein-reactive serums are frequently represented in the primary sequence of a protein, can be characterized by a set of simple chemical rules, and are confined neither to immunodominant regions of intact proteins nor to the amino or carboxyl terminals. As such, synthetic peptide immunogens are valuable for eliciting reagents with predetermined specificity that can be used for basic research. In addition, some synthetic peptides are capable of mimicking regions of virus proteins and eliciting immune responses in animals that are protective against the viral agents. Such peptides may thus serve as the basis for safe, chemically defined synthetic vaccines.
Dissolution and bioavailability of phenytoin in solid dispersion with phosphatidylcholine. (1988)

An attempt was made to improve the dissolution behavior of phenytoin (PHT), a poorly watersoluble drug, with phosphatidylcholine (PC) solid dispersion (SD). The powder X-ray diffraction patterns indicated that PHT was present in an amorphous state in SD when the molar fraction of PHT was under 0.33. Infrared spectra suggested a weak interaction, probably hydrogen bonding, between PC and PHT in SD. The solubility of PHT was 30μg/ml in both pH1.2 and 6.8 test solutions. The PHT concentration increased temporarily to 36μg/ml in both pH 1.2 and 6.8 test solutions with SD in which the molar fraction of PHT was 0.25 (SD (0.25)). This is only 1.2 times the PHT solubility, but the dissolution rate in pH 1.2 test solution was significantly improved: the PHT concentration reached 24μg/ml in the first 5min, whereas it was 6μg/ml in the case of PHT crystals. The dissolution rate was slightly higher even with physical mixture (PM) because of improved wettability.After oral administration of SD (0.25) to rabbits, plasma concentrations up to 8h were significantly higher than those in the cases of PM (0.25) and PHT crystals, but there was no significant difference in the area under the plasma concentration curve. PM (0.25) did not show improved bioavailability. These results were consistent with the results of the dissolution test at pH1.2. PM gave an increased plasma concentration of PHT if PC was used in a large excess over PHT (PM (0.10)), it was considered that PC functioned as an oil in this case.
Localized detection of glioma glycolysis using edited 1H MRS (1993)

In vivo 1H MRS can be used to detect and quantify the lactate resonance at 1.3 ppm provided that overlapping lipid resonances are eliminated. A homonuclear spectral editing method was developed to acquire uncontaminated 1H spectra of lactate with adiabatic pulses. An advantage of the adiabatic pulse sequence is the ability to induce uniform flip angles and to maximize sensitivity in applications employing surface coil transmitters which produce highly inhomogeneous B1. Glycolytic activity in an intracerebral C6 glioma in rats was monitored by using adiabatic editing sequences to observe [3-13C]lactate produced from infused [1-13C]glucose. Acute hyperglycemia (serum glucose > 22 mM, n = 10) had no significant effect (P = 0.08) on the total ([12C] + [13C]) tumor lactate signal intensity.
Polymer-stimulated ligation: enhanced ligation of oligo- and polynucleotides by T4 RNA ligase in polymer solutions (1984)

The effects of macromolecular crowding were tested on several reactions catalyzed by T4 RNA ligase. The rate of cyclization of oligoriboadenylates was stimulated up to 10-fold by relatively high concentrations of several polymers (polyethylene glycol (PEG) 8000 or 20,000; bovine plasma albumin; Ficoll 70). In addition, higher concentrations of PEG 8000 or PEG 20,000 allowed the novel formation of large linear products from the oligoriboadenylates. Also stimulated by high concentrations of PEG 8000 were the rate at which T4 RNA ligase joined p(dT)10 to oligoriboadenylates and the rate at which the enzyme activated p(dT)n by transfer of an adenylyl moiety from ATP to the oligonucleotides. These results with T4 RNA ligase are compared to earlier studies on the effects of crowding on DNA ligases.
Pulmonary defences to acute respiratory infection (2002)

Of all sites in the body, the lung is perhaps challenged by the greatest onslaught of microbial pathogens, many of which would cause lethal infections if unopposed. The immune response to respiratory infection must, therefore, be rapid and efficient. However, the respiratory tract is a fragile tissue with architecture that is finely designed for gas exchange, so that the price of excessive or inappropriate inflammatory responses may itself be very high. The first line of defence comes from barriers such as mucus and cilia, followed by a battery of mediators that constitute the innate response. These include lactoferrin, lysozyme, collectins and defensins. Activation of these molecules can lead directly to lysis of pathogens, or to destruction through opsonisation or the recruitment of inflammatory cells. The adaptive immune response includes the production of neutralising antibodies and the responses of T lymphocytes. Different populations of T lymphocytes may dramatically alter the balance between clearance of the pathogen and induction of tissue damage depending on the cytokines they secrete.
Introduction of a current waveform, waveshaping technique to limit conduction loss in high-frequency dc-dc converters suitable for space power (1990)

Space power supply manufacturers have tried to increase power density and construct smaller, highly efficient power supplies by increasing switching frequency. Incorporation of a power MOSFET as a switching element alleviates switching loss. However, values of R sub DS(on) (drain-to-source resistance in the on-state) for MOSFET's are of such magnitude to produce greater on-state losses than an equivalent BJT operated in saturation. This research serves to introduce a design concept, pertinent to low-voltage relatively-high-current applications, that minimizes the peak current through the switching element in order to reduce average power loss. Basic waveforms produced by different PWM and resonant mode topologies were examined. Theoretical analysis reveals that a ramp-sine current waveform could cut conduction power loss by at least 18% over a conventional Buck switching converter. A 14V, 14W combination quasi-resonant Buck/ZCS, Quasi-Resonant Buck dc-dc converter with an unregulated input voltage of 28 V was built for simplicity to demonstrate one particular waveshaping technique. This converter represents a useful example of an actual circuit which is capable of producing the desired ramp-sine switch-current waveform. Final results confirm improvement in conduction loss enhancing existing power MOSFET technology for use in dc-dc power conversion.
Standardized Myocardial Segmentation and Nomenclature for Tomographic Imaging of the Heart (2002)

Nuclear cardiology, echocardiography, cardiovascular magnetic resonance (CMR), cardiac computed tomography (CT), positron emission computed tomography (PET), and coronary angiography are imaging modalities that have been used to measure myocardial perfusion, left ventricular function, and coronary anatomy for clinical management and research. Although there are technical differences between these modalities, all of them image the myocardium and the adjacent cavity. However, the orientation of the heart, angle selection for cardiac planes, number of segments, slice display and thickness, nomenclature for segments, and assignment of segments to coronary arterial territories have evolved independently within each field. This evolution has been based on the inherent strengths and weaknesses of the technique and the practical clinical application of these modalities as they are used for patient management. This independent evolution has resulted in a lack of standardization and has made accurate intra- and cross-modality comparisons for clinical patient management and research very difficult, if not, at times, impossible.

Attempts to standardize these options for all cardiac imaging modalities should be based on the sound principles that have evolved from cardiac anatomy and clinical needs.1–3⇓⇓ Selection of standardized methods must be based on the following criteria:





An earlier special report from the American Heart Association, American College of Cardiology, and Society of Nuclear Medicine4 defined standards for plane selection and display orientation for serial …
Highly Stereoselective Brønsted Acid Catalyzed Synthesis of Spirooxindole Pyrans (2011)

A Brønsted acid-catalyzed Prins-type cyclization sequence to construct spirooxindole pyrans in high yields and excellent diastereoselectivity has been developed. The combination of a β-hydroxy dioxinone fragment and isatin dimethyl acetal generate oxa-spirooxindoles efficiently. These compounds are diversifiable scaffolds that tap into the rich chemistry of dioxinones.
Modulation of the Activity of an Avian Gene Transferred into a Mammalian Cell by Cell Fusion (1974)

Mouse A9 cells, deficient in hypoxanthine phosphoribosyltransferase (EC 2.4.2.8), were fused with normal chick erythrocytes and selected in hypoxanthine-aminopterin-thymidine medium for cells with hypoxanthine phosphoribosyltransferase activity. Recovered hybrid cells produced the chick hypoxanthine phosphoribosyltransferase exclusively, as demonstrated by electrophoretic mobility and immunoprecipitation tests, even though no chick chromosomes or chick cell-surface antigens could be identified in the hybrids. Surprisingly, the expression of the chick hypoxanthine phosphoribosyl-transferase activity in the mouse/chick hybrids required the presence of aminopterin in the growth medium; in its absence, enzyme synthesis decreased markedly. Because of the rapid and reversible modulation of hypoxanthine phosphoribosyltransferase activity, the hybrid cells could proliferate equally well in media containing hypoxanthine-aminopterin-thymidine or 8-azaguanine. Cellular selection was definitely ruled out as a possible cause. These results confirm previous reports that specific genetic information can be selectively transferred from one cell to another of a distant species. Furthermore, they demonstrate that an avian gene, whose activity is normally expressed constitutively, can become facultative when integrated into a mammalian cell. This seems to be the first instance where heterologous gene activity has been shown to be reversibly modulated in hybrid cells.