The Interaction Between the 90 kiloDalton Heat Shock Protein and Steroid Hormone Receptors. Part 1. The Association of hsp90 and ER in the MCF-7 Human Breast Cancer Cell Line. Part 2. The Effect of Temperature on the Androgen .Responsiveness of Two Human Prostate Cancer Cell Lines

Breast cancer is a major killler of adult women, yet effective therapies are few. Prostate disease (both benign prostate hypertophy-BPH and prostate cancer) afflicts a large proportion of adult males

Neurotransmitter Receptor Plasticity and Its Functional Consequences in Relation to Alzheimer's Disease

Neurotransmitter receptor sites have been examined in both human postmortem tissue and a lesioned polysynaptic pathway in rat brain using quantitative ligand binding autoradiography. Human Postmortem Studies The putative involvement of glutamatergic mechanisms in the pathophysiology of Alzheimer's disease (A. D. ) was investigated by determining the distribution and density of Na+ -dependent glutamate uptake sites and glutamate receptor subtypes; kainate, quisqualate and N-methyl-D-aspartate (NMDA), in adjacent sections of frontal, temporal and cerebellar cortex from six patients with A. D. and six age-matched controls. The number of senile plaques in each region was determined in adjacent sections to those used for receptor autoradiography. Binding of [3H]-D-aspartate to Na+-dependent uptake sites was reduced by approximately 40% throughout A. D. frontal cortex relative to controls, indicating a general loss of glutamatergic presynaptic terminals. [3H]-Kainate binding was significantly increased by approximately 70% in deep layers of A. D. frontal cortex compared to controls, but unaltered in superficial laminae. Scatchard analysis of this response indicated an increase in kainate receptor numbers with no change in receptor affinity. [3H]-Kainate binding and senile plaque numbers were positively correlated (r=0.914) in deep layers of A. D. frontal cortex, but unrelated in superficial laminae (r=0.089). There was a small reduction (25%) in NMDA-sensitive [3H]-glutamate binding only in superficial layers of A. D. frontal cortex relative to controls, although [3H]-glutamate binding in A. D. subjects was unrelated to senile plaque numbers in these cortical layers (r=0.104). Quisqualate receptors, as assessed by [3H]-a-amino-3-hydroxy-5-methylisoxazole-4-propionic acid ([3H]-AMPA) binding were unaltered in A. D. frontal cortex compared to controls. There was no significant alteration in any glutamate binding sites in A. D. temporal cortex relative to control brains, despite the presence of senile plaques in comparable numbers to those found in A. D. frontal cortex. However, in the molecular layer of cerebellar cortex from A. D. subjects, there was a significant reduction (40%) in the number of [3H]-AMPA binding sites indicating a loss of quisqualate receptors in this region. [3H]-D-aspartate, [3H]-kainate and NMDA-sensitive [3H]-glutamate binding were unaltered in either the molecular or granule cell layers of A. D. cerebellar cortex. Within the cerebellum, senile plaques were found in very small numbers in only two A. D. brains. These results indicate anatomically-selective alterations in glutamatergic sites within the A. D. brain. The association of the kainate response in frontal cortex with the level of local neuropathology and the loss of quisqualate receptors in the cerebellum in the absence of gross neuropathological change suggests that the mechanisms of glutamatergic dysfunction in A. D. are heterogeneous with respect to anatomical locus. Rat Visual System Studies The rat visual system was employed as a model polysynaptic pathway in which to examine neurotransmitter receptor alterations under conditions of functional deficit. Within the visual system, glutamate is the major excitatory transmitter, although serotonin, noradrenaline, acetylcholine and GABA (y-aminobutyric acid) are also involved in visual processing. Unilateral orbital enucleation experiments were undertaken to examine: (1) the response of glutamate receptor subtypes under conditions of reduced glutamatergic input; (2) receptor regulation in separate but functionally related systems, by simultaneously quantifying specific serotonergic, noradrenergic, GABAergic and cholinergic receptors post-lesion; and (3) the relevance of alterations in neurotransmitter receptors to changes in local cerebral function, by combining the [14C]-2-deoxyglucose technique for the measurement of cerebral glucose use with in vitro receptor autoradiography. The results presented in this thesis highlight the applicability of quantitative receptor autoradiography in studies of receptor dynamics in both rat polysynaptic systems and human neurodegenerative disease. The novel alterations in glutamatergic sites in the A. D. brain uncovered by the present investigations provide new insight into the role of glutamatergic dysfunction in the pathophysiology of the disease

Rhodium(III) and iridium(III) half-sandwich complexes with tertiary arsine and stibine ligands

This work was financially supported by the EPSRC and the EPSRC National Mass Spectrometry Service Centre (NMSSC) Swansea.The syntheses of rhodium(III) and iridium(III) half sandwich complexes containing tertiary arsine and stibine ligands of the form [Cp*M(L)Cl2] (M = Rh, Ir; L = AsEt3, AsPh3, SbPh3) are reported. These compounds represent infrequent examples of rhodium and iridium metal complexes bearing arsenic or antimony ligands. All new compounds were fully characterised using 1H and 13C NMR spectroscopy, mass spectrometry and single crystal X-ray diffraction. DFT calculations show the formation of the complexes from (Cp*MCl2)2 and EPh3 (E = P, As, Sb) to be highly exothermic, although the enthalpic driving force is decreasing in the expected sequence P > As > Sb.PostprintPeer reviewe

Sterically restricted tin phosphines, stabilized by weak intramolecular donor-acceptor interactions

Funding: Engineering and Physical Sciences Research Council (EPSRC)Four related sterically restricted pen-substituted acenaphthenes have been prepared containing mixed tin phosphorus moieties in the proximal 5,6-positions (Acenap[SnR3][(PPr2)-Pr-i]; Acenap = acenaphthene-5,6-diyl; R-3 = Ph-3 (1), Ph2Cl (2), Me2Cl (3), Bu2Cl (4)). The degree of intramolecular P-Sn bonding within the series was investigated by X-ray crystallography, solution and solid-state NMR spectroscopy, and density functional theory (DFT/B3LYP/SBKJC/PCM) calculations. All members of the series adopt a conformation such that the phosphorus lone pair is located directly opposite the tin center, promoting an intramolecular donor acceptor P -> Sn type interaction. The extent of covalent bonding between Sn and P is found to be much greater in triorganotin chlorides 2-4 in comparison with the triphenyl derivative 1. Coordination of a highly electronegative chlorine atom naturally increases the Lewis acidity of the tin center, enhancing the Ip(P)-sigma*(Sn-Y) donor acceptor 3c-4e type interaction, as indicated by conspicuously short Sn-P peri distances and significant (1)J(P-31,Sn-119) spin spin coupling constants (SSCCs) in the range 740-754 Hz. Evidence supporting the presence of this interaction was also found in solid-state NMR spectra of some of the compounds which exhibit an indirect spin spin coupling on the same order of magnitude as observed in solution. DFT calculations confirm the increased covalent bonding between P and Sn in 2-4, with notable WBIs of ca. 0.35 obtained, in comparison to 0.1 in 1.PostprintPeer reviewe

Novel clone selection technique reveals heterogeneity among HEK293T cells engineered to produce therapeutic extracellular vesicles

HEK293T cells have been engineered to produce extracellular vesicles (EVs) that deliver miR-199a-3p to CD44+ hepatocellular carcinoma cells. Restoration of this miRNA has been shown to slow cancer progression in-vitro. Isolation and analysis of EVs from cell culture media containing selection agent revealed that the number of miRNA-199a-3p copies was less than the number of cells in culture suggesting that not all cells produce therapeutic EVs. Therefore, therapeutic EV production can be significantly increased by selecting the HEK293T clones that produce the most therapeutic EVs. While clone selection is traditionally accomplished by cell analysis techniques such as fluorescence activated cell sorting (FACS), detection of therapeutic EVs poses a unique challenge in that cellular expression of miRNA-199a-3p does not necessarily correlate to the amount of exosomal miRNA-199a-3p. In response to this challenge, a fibrous microwell array was developed to screen thousands of clones for therapeutic EV productivity (figure 1). The fibrous microwell system is able to evaluate cell growth rate under fluid shear stress, EV productivity and EV characterization using fluorescently labeled antibodies or cationic lipoplex nanoparticles (detect presence of miRNA-199a-3p inside captured EVs produced by single clones). The most productive clones can be released from the microwells and grown in large scale cell culture to significantly increase therapeutic EV production. Please click Additional Files below to see the full abstract

Reactivity profile of a peri-substitution-stabilized phosphanylidene-phosphorane : synthetic, structural, and computational studies

The authors thank the EaStChem, EPSRC, and the COST actions CM0802 PhoSciNet and CM1302 SIPs for financial support.The reactions of peri-substitution-stabilized phosphanylidene-phosphorane 1 with [AuCl(tht)] or [PtCl2(cod)] afford binuclear complexes [((1)(AuCl)2)2] 2 and [((1)(PtCl2))2] 3, in which four electrons of the ligand are used in bonding to two metal atoms in the bridging arrangement. Reactions of 1 with [Mo(CO)4(nbd)] or (RhCl2Cp*)2 afford mononuclear complexes [(1)2Mo(CO)4] 4 and [(1)RhCl2Cp*] 5, in which two electrons of the ligand are used to form terminal complexes. Formation of these complexes disrupts the negative hyperconjugation at the P–P bond to various extents, which is mirrored by variations in their P–P bond distances (2.179(4)–2.246(4) Å). The P–P bond is ruptured upon formation of Pd diphosphene complex 6, which is likely to proceed through a phosphinidene intermediate. In air, 1 is fully oxidized to phosphonic acid 7. Reactions of 1 with chalcogens under mild conditions generally afford mixtures of products, from which the trithionated 8, dithionated 9, diselenated 10, and monotellurated 11 species were isolated. The bonding in the chalcogeno derivatives is discussed using DFT (B3LYP) and natural bond orbital analysis, which indicate a contribution from dative bonding in 8–10. The buttressing effect of the peri backbone is shown to be an essential factor in the formation of the single push–double-pull bis(borane) 13. This is demonstrated experimentally through a synthesis parallel to that used to make 13, but lacking the backbone, which leads to different products. The P–P bond distances in the reported products, as well as additional species, are correlated with Wiberg bond indices, showing very good agreement for a variety of bonding modes, including the negative hyperconjugation.PostprintPostprintPeer reviewe

Sterically encumbered tin and phosphorus peri-substituted acenaphthenes

The work in this project was supported by the Engineering and Physical Sciences Research Council (EPSRC), EaStCHEM and the University of St Andrews.A group of sterically encumbered peri-substituted acenaphthenes have been prepared, containing tin moieties at the 5,6-positions in 1 – 3 ([Acenap(SnR3)2], Acenap = acenaphthene-5,6-diyl; R3 = Ph3 ( 1 ), Me3 ( 2 ); [(Acenap)2(SnMe2)2] ( 3 )) and phosphorus functional groups at the proximal peri-positions in 4 and 5 ([Acenap(PR2)(PiPr2)] R2 = Ph2 ( 4 ), Ph(iPr) ( 5 )). Bis(stannane) structures 1 – 3 are dominated by repulsive interactions between the bulky tin groups, leading to peri-distances approaching the sum of van der Waals radii. Conversely, the quasi-linear CPh-P···P three-body fragments found in bis(phosphine) 4 suggest the presence of a lp(P)−σ*(P–C) donor–acceptor 3c-4e type interaction, supported by a notably short intramolecular P···P distance and notably large JPP through-space coupling (180 Hz). Severely strained bis(sulfides) 4-S and 5-S , experiencing pronounced in-plane and out-of-plane displacements of the exocyclic peri-bonds, have also been isolated following treatment of 4 and 5 with sulfur. The resulting nonbonded intramolecular P···P distances, ∼4.05 Å and ∼12% longer than twice the van der Waals radii of P (3.60 Å), are among the largest ever reported peri-separations, independent of the heteroatoms involved, and comparable to the distance found in 1 containing the larger Sn atoms (4.07 Å). In addition we report two metal complexes with square planar [( 4 )PtCl2] ( 4-Pt ) and octahedral cis-[( 4 )Mo(CO)4] ( 4-Mo ) geometries. In both complexes the bis(phosphine) backbone is distorted, but notably less so than in bis(sulfide) 4-S . All compounds were fully characterized, and except for bis(phosphine) 5 , crystal structures were determined.PostprintPostprintPeer reviewe

Patient-reported barriers to accepting a technological adherence package in the MAGNIFY trial.

Peer reviewedPostprin

Peri-substituted phosphorus-tellurium systems – an experimental and theoretical investigation of the P∙∙∙Te through-space interaction

The authors are thankful to the EPSRC, the EPSRC National Mass Spectrometry Service Centre (NMSSC) Swansea, the School of Chemistry St. Andrews, and EaStCHEM for support.A series of peri-substituted phosphorus-tellurium systems R’Te–Acenap–PR2 (R’ = Ph, p-An, Nap, Mes, Tip; R = iPr, Ph) exhibiting large “through space” spin-spin coupling constants and the “onset” of three-centre four-electron type interactions are presented. The influence of the substituents at the phosphorus and tellurium atoms as well as their behavior upon oxidation (with S, Se) or metal-coordination (Pt, Au) is discussed using NMR spectroscopy, single crystal X-ray diffraction, and advanced DFT studies including NBO, AIM and ELI-D analyses.PostprintPeer reviewe

Svjetlosna mikroskopija kristaličnih uklopina cucumovirusa mozaika bagrema

In cells infected with robinia mosaic cucumovirus (RoMV) we established two basic types of crystalline virus inclusions: hollow crystals, of polyhedral and spherical to oval appearance, and ordinary polyhedral crystals. The former seem regularly present in the vacuole, and the latter in the cytoplasm. The optimal temperatures for development of RoMV crystalline inclusions were betwenn 15—20°C at the period of longer days. All forms of the crystals were more freuquent in relatively younger cells in which more intense filling of the hollow crystals took place.U stanicama zaraženim cucumovirusom mozaika bagrema (RoMV) ustanovili smo dva osnovna tipa kristaličnih virusnih uklopina: prazne kristale poliedričnog i sferičnog oblika, i obične poliedralne kristale. Prazni se kristali, kako se čini, redovito nalaze u vakuoli, a obični poliedralni kristali u dtoplazmi. Najpovoljnije temperature za razvitak kristaličnih uklopina RoMV bile su između 15—20°C u periodu dužeg dana. Svi oblici kristala bili su češći u razmjerno mlađim stanicama u kojima se također odvijalo intenzivnije ispunjavanje praznih kristala