No description available.

No description available.

No description available.

The Hyp (hypophosphatemic) mouse, a murine homologue of X-linked hypophosphatemia (XLH) in man, is a Mendelian disorder of phosphate (Pi) homeostasis. The mutant genotype is characterized by abnormal Pi transport at the brush border membrane (BBM) of the proximal tubule and a defect in renal metabolism of vitamin D$ sb3$. The exact nature of these defects has not been elucidated. / In order to determine if the defect is intrinsic to the renal cell or dependent upon an extrinsic humoral factor, I established primary cultures of renal epithelial cells from normal and Hyp mouse kidney. The cultures demonstrated several differentiated properties of epithelial cells of the renal proximal tubule, the site of the Pi transport defect in the Hyp mouse. / Primary cultures initiated from Hyp mice had decreased Pi transport (expressed as an uptake ratio, Pi/$ alpha$-MG), and increased production of 24,25 dihydroxyvitamin D$ sb3$. These results provide evidence for the intrinsic nature of the primary defect in the Hyp mouse. / This appears to be the first time that expression of a mutant transport gene has been demonstrated in cultured renal cells.

No description available.

<p><font face="TimesNewRomanPSMT"> <p align="left">Life is an emergent property of a complex network of interacting cellular-machines. Three-dimensional (3D), cellular structure captured at supra-atomic resolution has the potential to revolutionise our understanding of the interactions, dynamics and structure of these machines: proteins, organelles and other cellular constituents, in their normal functional states. Techniques, capable of acquiring 3D cellular structure at sufficient resolution to enable identification and interpretation of individual macromolecules in the cellular milieu, have the potential to provide this data. Advances in cryo-preservation, preparation and metal-coating techniques allow images of the surfaces of in situ macromolecules to be obtained in a life-like state by field emission scanning &ndash / and transmission electron microscopy (FE/SEM, FE/TEM) at a resolution of 2-4 nm. A large body of macromolecular structural information has been obtained using these techniques, but while the images produced provide a qualitative impression of three-dimensionality, computational methods are required to extract quantitative 3D structure. In order to test the feasibility of applying various photogrammetric and tomographic algorithms to micrographs of well-preserved metal-coated biological surfaces, several algorithms were attempted on a variety of FE/SEM and TEM micrographs. A stereoscopic algorithm was implemented and applied to FESEM stereo images of the nuclear pore basket, resulting in a high quality digital elevation map. A SEM rotation series of an object of complicated topology (ant) was reconstructed volumetrically by silhouette-intersection. Finally, the iterative helical real-space reconstruction technique&nbsp / as applied to cryo-TEM micrographs of unidirectionally heavy-metal shadowed.&nbsp / These preliminary results confirm that 3D information obtained from multiple TEM or SEM surface images could be applied to the problem of 3D macromolecular imaging in the cellular context. However, each of the various methods described here comes with peculiar topological, resolution and geometrical limitations, some of which are inherent shortcomings of the methodologies described / others might be overcome with improved algorithms. Combined with carefully designed surface experiments, some of the methods investigated here could provide novel insights and extend current surface-imaging&nbsp / studies. Docking of atomic resolution structures into low-resolution maps derived from surface imaging experiments is a particularly exciting prospect.</p> </font></p>

Of the numerous l3-blockers clinically available to treat conditions such as angina pectoris, hypertension and heart failure, none possess antagonist activity specific to the beta1-adrenoceptor. Those described as 'cardioselective', such as nebivolol and bisoprolol, generally show less than 50-fold beta1/beta2-selectivity, which can be lost at higher doses. Others, such as propranolol and sotalol are actually more beta2-selective. Overall, a degree of concomitant beta2-adrenoceptor blockade (risking compromised respiratory function and loss of peripheral vasodilatation) by current therapeutic agents precludes their use in patients with disorders such as asthma and peripheral vascular disease. This project aims to develop novel molecules with much improved beta1/beta2-selectivity over current beta1-blocker therapy as well as improving knowledge of ligand-receptor interaction at the beta1-adrenoceptor, through an analogue-based drug discovery approach. A highly selective or specific beta1-adrenoceptor antagonist is likely to cause fewer side-effects and be suitable for use in previously contraindicated disease states. This thesis reports the design, synthesis and pharmacological data (provided by Dr. Jillian Baker) of a library of novel ligands for the beta1- adrenoceptor, based upon the lead compound LK 204-545. LK 204-545 was selected based on reported high potency at the beta1-adrenoceptor as well as good beta1/beta2-selectivity. Modification of various motifs on structures derived from LK 204-545 allowed the generation of new structure-activity relationships and ultimately afforded the highly 131-adrenoceptor selective compound, 1-(2-(3-(4-(2-(cyclopropylmethoxy)ethoxy)phenoxy)-2-hydroxypropyl amino)ethyl)-3-(4-hydroxyphenyl)urea hydroformate (12Sc). This compound acted as a highly-selective beta1-adrenoceptor antagonist in a pilot in-vivo study in the regional hemodynamic rat model (carried out by Prof. Sheila Gardiner).

If the problems of the subjective nature of colposcopy could be avoided, colposcopy could be a non-invasive method of allowing women to remain under safe surveillance whilst avoiding having tissue biopsies taken. This thesis presents an evaluation of different methods to identify a high risk group from women with mild dyskaryosis in the context of a prospective randomised trial. Chapter 1 describes the historical background to the management of low grade cytological abnormalities and the changes brought about by the introduction of colposcopy. This is used to put into context the current dilemma regarding the management of mild dyskaryosis. The role of human papillomavirus in the development of cervical neoplasia will be discussed with a literature review of current evidence to support its use as a secondary screening tool for cervical disease. Chapter 2 describes the design of this prospective randomised controlled trial including patient recruitment and randomisation and the trial protocol. Chapter 3 presents the histopathological outcome for each trial arm and evaluates the use of semi-quantitative HPV 16 detection with the current use of cytological surveillance as a method of secondary screening. Chapter 4 presents the results of a pilot study to compare the efficiency of a commercial HPV detection kit, hybrid capture, with semi-quantitative HPV 16 detection by polymerase chain reaction for women with mild dyskaryosis. Chapter 5 compares the value of objective measurement of colposcopic features of cervical intraepithelial neoplasia on digitised colposcopic images with subjective colposcopic assessment and comments on image digitising in the surveillance of women with mild dyskaryosis. Chapter 6 presents the socio-demographic data on the trial women and evaluates the ability of high risk behaviour to identify a high risk group from those women with mild dyskaryosis. Chapter 7 summarises the results of this trial and presents the main conclusions.

Plants collected in Wisconsin during September, 1970 were identified as P. ramosissimum and P. tenue according to the taxonomic characters established by Styles for European species of genus Polygonum and adapted for the North American species fo this genus by Mertens and Raven. The chromosome number for these two plants were determined to be 2n=60 for P. ramosissimum and 2n=30 or 32 for P. tenue. These counts were compared with chromosome numbers for Polygonum species for all of which the haploid count is either twenty or thirty. Chromatographic analysis of free amino acids and secondary substances further suggests that P. ramosissimum is properly assigned to section Polygonum while P. tenue should be placed in some other section of genus Polyyonum.

Characterisation of expression of functional Peroxisome Proliferator Activated Receptora (PPARalpha)receptor in rodent species responsive and non-responsive to peroxisome proliferators is important for our understanding of the molecular mechanism of peroxisome proliferation and peroxisome proliferator induced hepatocarcinogenesis. In vitro electromobility shift assays, demonstrated that rodent liver nuclear proteins (LNP) bound to a Peroxisome Proliferator Response Element (PPRE) in a sequence specific manner and that LNP from methylclofenapate (MCP) treated mice do not have enhanced binding to a PPRE. These results demonstrate that in MCP treated mice, PPAR alpha levels with functional DNA binding do not increase. The diurnal expression of mouse PPAR alpha (mPPARalpha) protein in liver was examined by western blotting. There was no observable difference in the expression of mPPARalpha across a 24 hour period. In C57 BL/6 mice, PPARalpha protein levels are not regulated in a diurnal manner. A comparison of mouse and guinea pig LNP revealed a PPARalpha-immunoreactive protein in guinea pig. Guinea Pig PPARalpha (gPPAR a) was cloned and found to encode a 467 amino acid protein. Phylogenetic analysis of gPPARalpha showed a high substition rate: maximum likelihood analysis was consistent with rodent monophyly, but could not exclude rodent polyphyly (p~0.07). The gPPAR alpha cDNA was expressed in 293 cells, and mediated the induction of the luciferase reporter gene by the peroxisome proliferator Wy-14,643, dependent upon the presence of a PPRE. The gPPAR alpha mRNA and protein was expressed in guinea pig liver, although at lower levels compared to PPAR alpha expression in mice. The evidence presented here supports the idea that guinea pigs serve as a useful model for human responses to peroxisome proliferators. mPPAR alpha DNA binding domain (mPPARalpha-DBD) was cloned and expressed as a fusion protein. Both His*6-mPPARalpha-DBD and thioredoxin-mPPARalpha-DBD were produced as insoluble proteins when over expressed in E.coli. In vitro translated mPPAR alpha-DBD did not bind to a PPRE in an electromobility shift assay.