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Biomedical subjects

G Freshour

Publications and source records attributed to G Freshour.

4 recordsLinked to original sources

Renal disease in rats with type 2 diabetes is associated with decreased renal nitric oxide production.

AIMS/HYPOTHESIS: In several other models of chronic renal disease, decreases in renal nitric oxide activity and nitric oxide synthase (NOS) protein abundance have been demonstrated. Here, we studied diabetic obese Zucker (ZDF Gmi fa/fa) rats that develop severe hyperglycaemia and renal disease, together with their lean control animals, to determine if renal nitric oxide deficiency also occurs in this model. METHODS: Obese Zucker rats aged 10 to 12 weeks were maintained on Purina 5008 diet until 4, 8, or 11 months of age and compared with similarly maintained, 4- and 11-month-old lean Zucker rats. NOS activity and abundance of endothelial NOS (eNOS) and neuronal NOS (nNOS) were measured on homogenates of kidney cortex. Blood was analysed for glucose, lipids, creatinine, and blood urea nitrogen and kidney tissue was obtained for histology. RESULTS: Obese rats exhibited severe hyperglycaemia from 4 months of age and developed increasing hyperlipidaemia, proteinuria, and decreasing renal function with age compared to lean counterparts. At 4 months cortical NOS activity and nNOS abundance were lower in obese rats than in lean ones. At 11 months NOS activity remained depressed and nNOS abundance had declined further in obese rats. Glomerulosclerosis in the obese rats was mild at 4 months, becoming severe by 11 months. Lean rats had only mild age-dependent increases in glomerular injury. CONCLUSIONS/INTERPRETATION: The chronic renal disease that occurs in hyperglycaemic, obese Zucker rats is associated with decreased renal cortical nitric oxide production and increasing renal injury, although the changes do not resemble those of diabetic nephropathy in man.

Animals↗

The SCARECROW gene regulates an asymmetric cell division that is essential for generating the radial organization of the Arabidopsis root.

In the Arabidopsis root meristem, initial cells undergo asymmetric divisions to generate the cell lineages of the root. The scarecrow mutation results in roots that are missing one cell layer owing to the disruption of an asymmetric division that normally generates cortex and endodermis. Tissue-specific markers indicate that a heterogeneous cell type is formed in the mutant. The deduced amino acid sequence of SCARECROW (SCR) suggests that it is a member of a novel family of putative transcription factors. SCR is expressed in the cortex/endodermal initial cells and in the endodermal cell lineage. Tissue-specific expression is regulated at the transcriptional level. These results indicate a key role for SCR in regulating the radial organization of the root.

Amino Acid Sequence↗

An antibody Fab selected from a recombinant phage display library detects deesterified pectic polysaccharide rhamnogalacturonan II in plant cells.

Rhamnogalacturonan II (RG-II) is a structurally complex, low molecular weight pectic polysaccharide that is released from primary cell walls of higher plants by treatment with endopolygalacturonase and is chromatographically purified after alkaline deesterification. A recombinant monovalent antibody fragment (Fab) that specifically recognizes RG-II has been obtained by selection from a phage display library of mouse immunoglobulin genes. By itself, RG-II is not immunogenic. Therefore, mice were immunized with a neoglycoprotein prepared by covalent attachment of RG-II to modified BSA. A cDNA library of the mouse IgG1/kappa antibody repertoire was constructed in the phage display vector pComb3. Selection of antigen-binding phage particles resulted in the isolation of an antibody Fab, CCRC-R1, that binds alkali-treated RG-II with high specificity. CCRC-R1 binds an epitope found primarily at sites proximal to the plasma membrane of suspension-cultured sycamore maple cells. In cells deesterified by alkali, CCRC-R1 labels the entire wall, suggesting that the RG-II epitope recognized by CCRC-R1 is masked by esterification in most of the wall and tha such RG-II esterification is absent near the plasma membrane.

Animals↗