gebhart/patrepeval huggingface dataset:
The First Highly Active, Halide-Free Ruthenium Catalyst for Olefin Metathesis (2003)

New ruthenium alkylidyne and alkylidene complexes are prepared, in which aryloxide groups function as pseudohalide ligands. The selectivity for alkylidene or alkylidyne products is controlled by steric matching or mismatching between pseudohalide and ancillary donor ligands. Alkylidene 5 achieves up to 40 000 turnovers in ring-closing metathesis of diethyl diallylmalonate.
Liposome mediated in vivo gene transfer into different tissues of the gastrointestinal tract. (1994)

The possibility to transfer and express genetic material in mammalian cells represents a new approach to the treatment of genetic and acquired disorders. So far, most studies use in vitro techniques to introduce foreign DNA into cultured cells, followed by reintroduction of these genetically altered cells into living organisms. In the present study we demonstrate that the LacZ marker gene can be selectively delivered, by in vivo techniques, to various locations of the gastrointestinal tract. Genetic material was targeted to the stomach, the colon, the liver and the pancreas using cationic liposomes. For transfer into the stomach and colon an intraluminal application, in the liver a portal access and in the pancreas an intraductal infusion was chosen. 48 hours after administration, the LacZ gene product beta-galactosidase could be localized in these tissues by cytochemistry. These experiments suggest a new approach to study gastrointestinal physiology and may offer novel aspects for the treatment of gastrointestinal diseases.
Olfactory Receptor Neurons in Partially Purified Epithelial Cell Cultures: Comparison of Techniques for Partial Purification and Identification of Insulin as an Important Survival Factor (2000)

Olfactory neurons have the rare property of being replaced throughout life. Factors regulating different developmental stages of olfactory receptor neurons (ORNs) are of great interest, because such factors might be used to extend regeneration in the post-developmental brain and spinal cord. Also, these factors may potentially be exploited to treat various smell disorders arising from changes in the olfactory epithelium. Characterization of trophic factors for ORNs requires cell culture systems that are simple and easy to manipulate. We have compared four different cell culture preparations, using two different enzymes and two different media to develop a simple culture system of olfactory epithelial cells. Our preferred preparation, which produces partially purified olfactory epithelial cultures, uses trypsin dissociation and a serum-free keratinocyte growth medium (KGM) supplemented with insulin. These conditions support ORN survival up to 1 week. They also supported other elements of the olfactory epithelium such as Bowman's gland cells and horizontal basal cells. Olfactory epithelial cells predominate, while contaminating mesenchymal cells (glia and fibroblasts) are present in low numbers. Using these cultures, it was determined that insulin was required for ORN survival in vitro. The simplicity of the epithelial cultures will be useful for further studies of insulin and other ORN trophic factors.
Non-Abelian Statistics of Half-Quantum Vortices in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi mathvariant="italic">p</mml:mi></mml:math>-Wave Superconductors (2001)

Excitation spectrum of a half-quantum vortex in a p-wave superconductor contains a zero-energy Majorana fermion. This results in a degeneracy of the ground state of the system of several vortices. From the properties of the solutions to Bogoliubov-de Gennes equations in the vortex core we derive the non-Abelian statistics of vortices identical to that for the Moore-Read (Pfaffian) quantum Hall state.
Somatostatin receptor subtype 2 sensitizes human pancreatic cancer cells to death ligand-induced apoptosis (2002)

Somatostatin receptor subtype 2 (sst2) gene expression is lost in 90% of human pancreatic adenocarcinomas. We previously demonstrated that stable sst2 transfection of human pancreatic BxPC-3 cells, which do not endogenously express sst2, inhibits cell proliferation, tumorigenicity, and metastasis. These sst2 effects occur as a consequence of an autocrine sst2-dependent loop, whereby sst2 induces expression of its own ligand, somatostatin. Here we investigated whether sst2 induces apoptosis in sst2-transfected BxPC-3 cells. Expression of sst2 induced a 4.4- +/- 0.05-fold stimulation of apoptosis in BxPC-3 through the activation of tyrosine phosphatase SHP-1. sst2 also sensitized these cells to apoptosis induced by tumor necrosis factor alpha (TNFalpha), enhancing it 4.1- +/- 1.5-fold. Apoptosis in BxPC-3 cells mediated by TNF-related apoptosis-inducing ligand (TRAIL) and CD95L was likewise increased 2.3- +/- 0.5-fold and 7.4- +/- 2.5-fold, respectively. sst2-dependent activation and cell sensitization to death ligand-induced apoptosis involved activation of the executioner caspases, key factors in both death ligand- or mitochondria-mediated apoptosis. sst2 affected both pathways: first, by up-regulating expression of TRAIL and TNFalpha receptors, DR4 and TNFRI, respectively, and sensitizing the cells to death ligand-induced initiator capase-8 activation, and, second, by down-regulating expression of the antiapoptotic mitochondrial Bcl-2 protein. These results are of interest for the clinical management of chemoresistant pancreatic adenocarcinoma by using a combined gene therapy based on the cotransfer of genes for both the sst2 and a nontoxic death ligand.
PREVALENCE OF OCCULT HEPATITIS B INFECTION IN RENAL TRANSPLANT PATIENTS. (2004)

A122 Aims. Occult hepatitis B (HB) is characterized by the presence of HBV DNA in patients who do not present HB surface antigen (HBsAg) detectable in sera. This condition is frequently described in patients with hepatitis C virus (HCV) infection and its clinical implications are uncertain. Since transplant patients were at risk for hepatits B and/or C infection by blood transfusions, dialysis treatment and the transplant procedure itself we aimed to evaluate the prevalence of occult HB either with or without HCV infection. Methods. One hundred and one HBsAg negative renal transplant patients were evaluated. Fifty-one were anti-HCV reagents (Elisa III). Sera was analysed for the presence of the S and core genes of the HBV DNA by a nested PCR technique. Serological markers of HBV infection, liver function testes and ciclosporine through levels were also analysed. Results. The core gene of the HBV DNA was identified in one HCV infected patient and in one anti-HCV negative who also presented the S gene (prevalence: 2% and 1% for each gene respectivelly). HCV infected patients presented longer pre-transplant dialysis time (50.8 ± 34.6 versus 32.0 ± 20.9 months; p<0,001). Results of liver function tests were also increased in the HCV infected group: ALT: 34.5 ± 26.7 × 20.9 ± 10.0 U/l; (P < 0.001); AST: 31.7 17.7 × 24.9 ± 14.9 U/l; (P < 0.05); GGT: 66.1 ± 82.4 × 33.4 ± 44.6 U/l; (P < 0.02) and alkaline phosphatase: 307.9 ± 397.7 × 186.9 ± 63.4 U/l; (P< 0.04). Ciclosporine through levels were also significantly higher in HCV infected patients 170.9 ± 69.8 and 135.0 ± 48.1 ng/ml respectivelly (P < 0.02). Multivariate analysis revealed that only HCV infection was determinant of the increased LFTs levels. Conclusion. We found that occult hepatitis B is an infrequent condition in our population of renal transplant patients and that HCV infection seems not to be a risk factor. In accordance with our previous work HCV we showed that infected renal transplant patients present evidence of liver damage and altered metabolism evidenced by the elevated liver function testes a higher ciclosporine through levels.
Surface plasmon assisted directional laserlike emission from a highly scattering dye doped polymeric gain medium (2002)

Summary form only given. The first observation of laserlike emission from a scattering medium consisting of TiO/sub 2/ particles in a dye solution was reported a few years ago. The emission from such system, which was named "laser paint" (LP) exhibits the characteristics of a multimode laser oscillator, although no resonant cavity is used. The phenomenon has been well studied but the LP-emission, which is almost spatially isotropic, would be more useful for applications if a scheme could be developed for obtaining directional emission. In this communication we report the first observation of quasi-directional LP-emission. The experiments were performed with a sample of a PMMA flat disc doped with Rhodamine.
In vitro Photoinduced Cytotoxicity and DNA Binding Properties of Psoralen and Coumarin Conjugates of Netropsin Analogs: DNA Sequence-Directed Alkylation and Cross-Link Formation (1994)

he synthesis, DNA binding and in vitro photoinduced cytotoxic properties of a number of minor groove and sequence-directed psoralen and coumarin conjugates of pyrrole- and imidazole-containing distamycin analogues 2-5 are described. Results from an ethidium displacement assay on calf thymus and T4 DNA suggest that like distamycin these agents bind strongly to the minor groove of DNA. The data show that these conjugates exhibit a lower AT preference than distamycin and the decrease is significantly greater for the imidazole-containing compounds. All of the compounds along with 8-methoxypsoralen, 1, were relatively noncytotoxic in the dark with only the imidazole-psoralen compound 3 giving an IC50 value below 100 microM. Following UV activation, all compounds showed an increased potency with photoinduced dose modifications in the human chronic myeloid leukemia K562 cells of > 333, 12, > 1.3, and > 2.5 for compounds 2-5, respectively, under the UV irradiation conditions employed. The psoralen-pyrrole analogue 2 was over 300 times more active following UV activation than agent 1, 250 times more potent than the corresponding coumarin conjugate 4, and 15-fold more potent than its imidazole analogue 3. Data from CD dilution (with DMF) studies show that upon irradiation with light at 366 nm, compounds 2-5 bind irreversibly to DNA. Furthermore, upon irradiation compound 2 produced interstrand cross-linked DNA in quantitative yield, with isolated DNA, at > 300- and > 3000-fold lower drug concentrations than the imidazole analogue 3 and 8-methoxypsoralen, respectively. As expected coumarin conjugates 4 and 5 did not produce any cross-linked DNA under any conditions. Since the psoralen conjugates are more phototoxic than their coumarin analogues, these results suggest that DNA interstrand cross-link formation may be an important mechanism by which they exert their biological activity in cells. In addition, the enhanced photocytotoxic potency of conjugate 2 over 3 may be related to its larger binding constant, more efficient DNA cross-linking ability, and possibly to its preference for AT-rich sequences.
The sequence of a 6.3 Kb segment of yeast chromosome lll reveals an ORF coding for a putative mismatch binding protein. (1992)

We report the sequence of a 6.3 kb segment of DNA mapping near the end of the right arm of chromosome III of Saccharomyces cerevisiae. The sequence reveals a major open reading frame coding for a putative protein of 1047 amino acids with a striking similarity to the bacterial proteins involved in recognition of mismatched DNA base pairs. This is particularly interesting as the existence of a yeast mismatch repair system similar to that of bacteria has been postulated for some years, but a yeast protein homologous to the bacterial mismatch binding protein had not been identified. The results of a comparison of the putative yeast mismatch binding protein with the bacterial mismatch binding proteins and with two cognate mammalian sequences, support the idea that a similar mismatch repair system may be present also in mammalian cells. The possibility that all of these proteins may have evolved from a common ancestral gene is also discussed.
Stomatal development in Arabidopsis and grasses: differences and commonalities (2011)

Stomata, found on the epidermis of all terrestrial plants, consist of two specialized cells called guard cells, which surround a tiny pore. Major advances have been made in our understanding of the genetic control of stomatal development in Arabidopsis and grasses. In Arabidopsis, three basic-helix-loop-helix (bHLH) genes control the successive steps that lead to stomatal formation. SPEECHLESS (SPCH) drives the cell division that initiates the stomatal cell lineage, MUTE induces the formation of the immediate stomatal precursor cell, and FAMA causes the stomatal precursor cell to divide into the two guard cells. Recent results demonstrate that these genes share functions with their grass homologs, and that MUTE is expressed later in development than its grass counterparts. Other differences in stomatal development between these two plant groups are exemplified by the PANGLOSS1 (PAN1) gene of maize. PAN1, which encodes a leucine-rich repeat receptor-like kinase with an inactive kinase domain, promotes polarization of the subsidiary mother cell and orients its cell division plane. Because such events do not exist in Arabidopsis, it is likely that the PAN1-like genes of Arabidopsis and PAN1 are paralogs. Together, these results indicate that distinctions in the regulation of gene expression and protein function are both responsible for the divergence of stomatal development between Arabidopsis and grasses.
Cytosolic androgen receptor in regenerating rat levator ani muscle (1981)

The development of the cytosolic androgen receptor was studied after degeneration and regeneration of the rat levator ani muscle after a crush lesion. Muscle regeneration appears to recapitulate myogenesis in many respects. It therefore provides a model tissue in sufficiently in large quantity for investigating the ontogenesis of the androgen receptor. The receptor in the cytosol of the normal levator ani muscle has binding characteristics similar to those of the cytosolic receptor in other androgen-sensitive tissues. By day 3 after a crush lesion of the levator ani muscle, androgen binding decreased to 25% of control values. This decrease was followed by a 4-5 fold increase in hormone binding, which attained control values by day 7 after crush. Androgen binding remained stable at the control value up to day 60 after crushing. These results were correlated with the morphological development of the regenerating muscle after crushing. It is concluded that there is little, if any, androgen receptor present in the early myoblastic stages of regeneration; rather, synthesis of the receptor may occur after the fusion of myoblasts and during the differentiation of myotubes into cross-striated muscle fibres.
Use of uterine EMG and cervical LIF in monitoring pregnant patients (2005)

The potential benefits of the proposed instrumentation include the following: a reduction in the rate of preterm birth, improved maternal and perinatal outcome, better monitoring of treatment, decreased caesarean section rate and better research methods for understanding uterine and cervical function.
Divergent Inducible Expression of P-Selectin and E-Selectin in Mice and Primates (1999)

We used in vitro and in vivo approaches to examine whether tumor necrosis factor-alpha (TNF-alpha) and oncostatin M (OSM), cytokines that bind to distinct classes of receptors, differentially regulate expression of P- and E-selectin in murine and primate endothelial cells. In human umbilical vein endothelial cells, TNF-alpha rapidly increased mRNA for E-selectin but not P-selectin. OSM elicited little or no change in mRNA for E-selectin, but induced a delayed and prolonged increase in P-selectin mRNA. TNF-alpha and OSM did not cooperate to further enhance P- or E-selectin mRNA. Intravenous infusion of Escherichia coli, which markedly elevates plasma lipopolysaccharide and TNF-alpha, increased mRNA for E-selectin but not P-selectin in baboons. In murine bEnd.3 endothelioma cells, TNF-alpha and OSM individually and cooperatively increased mRNA and protein for both P- and E-selectin. Intravenous injection of these cytokines also individually and cooperatively increased mRNA for P- and E-selectin in mice. We conclude that the murine P- and E-selectin genes respond to both TNF-alpha and OSM, whereas the primate P- and E-selectin genes have much more specialized responses. Such differences should be considered when extrapolating the functions of P- and E-selectin in murine models of inflammation to humans.
In Vivo and in Vitro Characterization of Ser477X Mutations in Polyhydroxyalkanoate (PHA) Synthase 1 from <i>Pseudomonas</i> sp. 61−3:  Effects of Beneficial Mutations on Enzymatic Activity, Substrate Specificity, and Molecular Weight of PHA (2006)

Evolutionary engineered polyhydroxyalkanoate (PHA) synthases from Pseudomonas sp. 61-3 enhance PHA accumulation and enable the monomer composition of PHAs to be regulated. We characterized a newly screened Ser477Arg (S477R) mutant of PHA synthase by in vivo analyses of P(3-hydroxybutyrate) [P(3HB)] homopolymer and P(3HB-co-3-hydroxyalkanoate) [P(3HB-co-3HA)] copolymer productions in the recombinants of Escherichia coli. The results indicated that the S477R mutation contributed to a shift in substrate specificity to smaller monomers containing a 3HB unit rather than to an enhancement in catalytic activity. Multiple mutations of S477R with other beneficial mutations, for example, Ser325Cys, exhibited synergistic effects on both an increase in PHA production (from 9 wt % to 21 wt %) and an alteration of substrate specificity. Furthermore, the effects of complete amino acid substitutions at position 477 were characterized in terms of in vivo PHA production and in vitro enzymatic activity. The five mutations, S477Ala(A)/Phe(F)/His(H)/Arg(R)/Tyr(Y), resulted in a shift in substrate specificity to smaller monomer units. The S477Gly(G) mutant greatly enhanced activity toward all different sizes of substrates with carbon numbers ranging from 4 to 12. These results indicated that the residue 477 contributes to both the catalytic activity and substrate specificity of PHA synthase. In recombinant E. coli, the S477A/F/G/H/R/Y mutations consistently led to increases (up to 6 times that of wild-type enzyme) in weight average molecular weights of P(3HB) homopolymers. On the basis of our studies, we created a structural feasibility accounting for the mutational effects on enzymatic activity and substrate specificity of PHA synthase.
lnterleukin-1 Stimulates and<i>All-Trans</i>-Retinoic Acid Inhibits Collagenase Gene Expression through Its 5′ Activator Protein-1-Binding Site (1990)

Collagenase production by synovial fibroblast-like cells (synoviocytes) plays a major role in cartilage and bone destruction in rheumatoid arthritis. Interleukin-1 (IL-1) increases collagenase secretion by elevating the steady state levels of collagenase mRNA in cultured rheumatoid synoviocytes, while all-trans-retinoic acid (RA) has the opposite effect. We have studied the regulation of collagenase gene transcription by IL-1 and RA in synoviocytes by transient transfection of plasmid constructs containing deletion mutants of the 5'-flanking region of the collagenase gene or the isolated phorbol ester-responsive element ligated to a chloramphenicol acetyltransferase reporter gene. We show that the phorbol ester-responsive element of the collagenase gene mediates both positive and negative regulatory effects, respectively, of IL-1 and RA on transcription. In addition, we show that IL-1 and 12-O-tetradecanoyl-phorbol-13-acetate transiently induce c-jun and c-fos expression and that retinoic acid inhibits IL-1 and 12-O-tetradecanoyl-phorbol-13-acetate induction of c-fos, but not c-jun. These results suggest that RA inhibits collagenase transcription at least in part through inhibition of c-fos.
Optical Manipulation of Nano Materials under Quantum Mechanical Resonance Conditions (2005)

We make a theoretical study about the laser-induced radiation force exerted on nano materials under a quantum mechanical resonance condition of electronic systems confined in them. In our recent study [1], we have clarified that the remarkable effects of the electronic resonance appear in the radiation force on the small object whose size is much smaller than the light wavelength; (A) the acceleration on the object gets larger as the size decreases, (B) the peaks with less heat appear in the force spectra even under the resonance condition, (C) the peak position sensitively varies with the nanoscale-size changes. These are useful for the optical manipulation to precisely control the mechanical motions of nano materials. In this paper, toward the experiment to verify the above results, we discuss the dependence of the mechanical motion of nano objects on the width of the incident laser light, and on the diffusion and friction effects assuming that they are floating in the superfluid helium-4 with the cryogenic condition where the electronic resonance effects become conspicuous. The results of calculations show that the particular nano objects, whose resonance energy corresponds to the center frequency of incident laser, can move away from others over macroscopic distance beyond diffusion length. This means that we can observe the distribution of sizes and qualities of nano objects as a macroscopic spatial distribution of them if we prepare appropriate conditions of incident light. We call this new technique 'Nano Optical Chromatography (NOC).
Development and characterization of chitosan-PEG-TAT nanoparticles for the intracellular delivery of siRNA (2013)

Recently, cell-penetrating peptides have been proposed to translocate antibodies, proteins, and other molecules in targeted drug delivery. The proposed study presents the synthesis and characterization of a peptide-based chitosan nanoparticle for small interfering RNA (siRNA) delivery, in-vitro. Specifically, the synthesis included polyethylene glycol (PEG), a hydrophilic polymer, and trans-activated transcription (TAT) peptide, which were chemically conjugated on the chitosan polymer. The conjugation was achieved using N-Hydroxysuccinimide-PEG-maleimide (heterobifunctional PEG) as a cross-linker, with the bifunctional PEG facilitating the amidation reaction through its N-Hydroxysuccinimide group and reacting with the amines on chitosan. At the other end of PEG, the maleimide group was chemically conjugated with the cysteine-modified TAT peptide. The degree of substitution on chitosan with PEG and on PEG with TAT was confirmed using colorimetric assays. The resultant polymer was used to form nanoparticles complexing siRNA, which were then characterized for particle size, morphology, cellular uptake, and cytotoxicity. The nanoparticles were tested in-vitro on mouse neuroblastoma cells (Neuro2a). Particle size and surface charge were characterized and an optimal pH condition and PEG molecular weight were determined to form sterically stable nanoparticles. Results indicate 7.5% of the amines in chitosan polymer were conjugated to the PEG and complete conjugation of TAT peptide was observed on the synthesized PEGylated chitosan polymer. Compared with unmodified chitosan nanoparticles, the nanoparticles formed at pH 6 were monodispersed and of <100 nm in size, exhibiting maximum cell transfection ability and very low cytotoxicity. Thus, this research may be of significance in translocating biotherapeutic molecules for intracellular delivery applications.