ATYPICAL FEMORAL FRACTURES AFTER LONG-TERM BISPHOSPHONATES THERAPY: CASE REPORT.

UNLABELLED: We present a 77-year-old woman with no histor of trauma, or associated with low-energy trauma, admitted to our clinic after three weeks of a left femoral fracture threated in Orthopedic Clinic. The patient was in treatment with bisphosphonates over 10 years for osteoporosis. DISCUSSION AND CONCLUSIONS: The causal re lationship between prolonged bisphosphonate use and the occurrence of atypical femora fractures (AFF) has not yet been established. For the patient at high risk of fracture, it may be beneficial to continue bisphosphonate treatment beyond five years. The absolute risk of atypical femoral fractures is low (about 100 cases per 100,000 person-years among long term users). For most people with osteoporosis, the proven fragility-fracture risk-reduction. benefits of bisphosphonates outweigh the risks of AFF.

Prediction of the lipophilicity of nine new synthesized selenazoly and three aroyl-hydrazinoselenazoles derivatives by reversed-phase high performance thin-layer chromatography.

Using reversed-phase high-performance thin-layer chromatography and a methanol-water mixture as the mobile phase, the lipophilicity of 12 new synthesized derivatives is studied. The first eight compounds have as a basic chemical structure aryliden-hydrazino-selenazoles, and the second group of the three compounds belongs to aroyl-hydrazinoselenazoles. The linear correlation between R(Mw) and the methanol-water ratios showed high values for the correlation coefficient. The chromatographic hydrophobic index is determined by using the ratio -R(Mw)/S, and the obtained values ranged between 99 and 73. A good linear correlation is obtained between R(Mw) and the slope. The log P values are calculated using ACD/Labs Software. The matrices are formed with R(Mw) and log P and are subjected to a principal component analysis (PCA). The best way to extract information from PCA is graphically, by plotting the obtained matrices. By analyzing the scores, the compounds can be grouped as follows: a group containing nine compounds, and a second one containing three compounds. Each group of compounds has the same basic chemical structure.

Effect of E. coli heat-stable enterotoxin on colonic transport in guanylyl cyclase C receptor-deficient mice.

We studied the functional importance of the colonic guanylyl cyclase C (GCC) receptor in GCC receptor-deficient mice. Mice were anesthetized with pentobarbital sodium, and colon segments were studied in Ussing chambers in HCO3- Ringer under short-circuit conditions. Receptor-deficient mouse proximal colon exhibited similar net Na+ absorption, lower net Cl- absorption, and a negative residual ion flux (J(R)), indicating net HCO3- absorption compared with that in normal mice. In normal mouse proximal colon, mucosal addition of 50 nM Escherichia coli heat-stable enterotoxin (STa) increased the serosal-to-mucosal flux of Cl- (J(s-->m)(Cl)) and decreased net Cl- flux (J(net)(Cl)) accompanied by increases in short-circuit current (I(sc)), potential difference (PD), and tissue conductance (G). Serosal STa had no effect. In distal colon neither mucosal nor serosal STa affected ion transport. In receptor-deficient mice, neither mucosal nor serosal 500 nM STa affected electrolyte transport in proximal or distal colon. In these mice, 1 mM 8-bromo-cGMP produced changes in proximal colon J(s-->m)(Cl) and J(net)(Cl), I(sc), PD, G, and J(R) similar to mucosal STa addition in normal mice. We conclude that the GCC receptor is necessary in the mouse proximal colon for a secretory response to mucosal STa.

Effects of short chain fatty acids on colonic Na+ absorption and enzyme activity.

Short chain fatty acids (SCFA) stimulate colonic Na+ absorption and inhibit cAMP and cGMP-mediated Cl- secretion. It is uncertain whether SCFA have equivalent effects on absorption and whether SCFA inhibition of Cl- secretion involves effects on mucosal enzymes. Unidirectional Na+ fluxes were measured across stripped colonic segments in the Ussing chamber. Enzyme activity was measured in cell fractions of scraped colonic mucosa. Mucosal 50 mM acetate, propionate, butyrate and poorly metabolized isobutyrate stimulated proximal colon Na+ absorption equally (300%). Neither 2-bromo-octanoate, an inhibitor of beta-oxidation, nor carbonic anhydrase inhibition affected this stimulation. All SCFA except acetate stimulated distal colon Na+ absorption 200%. Only one SCFA affected proximal colon cGMP phosphodiesterase (PDE) (18% inhibition by 50 mM butyrate). All SCFA at 50 mM stimulated distal colon cAMP PDE (24-43%) and decreased forskolin-stimulated mucosal cAMP content. None of the SCFA affected forskolin-stimulated adenylyl cyclase in distal colon or ST(a)-stimulated guanylyl cyclase in proximal colon. Na+-K+-ATPase in distal colon was inhibited 23-51% by the SCFA at 50 mM. We conclude that all SCFA (except acetate in distal colon) stimulate colonic Na+ absorption equally, and the mechanism does not involve mucosal SCFA metabolism or carbonic anhydrase. SCFA inhibition of cAMP-mediated secretion may involve SCFA stimulation of PDE and inhibition of Na+-K+-ATPase.

Up-regulation of extracellular matrix proteoglycans and collagen type I in human crescentic glomerulonephritis.

BACKGROUND: The pathogenesis of crescentic glomerulonephritis (CGN) involves cellular migration and proliferation in the urinary space, frequently followed by fibrous organization. Extracellular matrix proteoglycans (PGs) may regulate these events via effects on cellular migration, interactions with growth factors, including transforming growth factor-beta (TGF-beta), and control of collagen fibrillogenesis. The expression of PG in human CGN is unknown. METHODS: Renal tissues from 18 patients with CGN were examined immunohistochemically for versican, decorin, biglycan and collagen type I, and were compared with morphologically normal tissues from six tumor nephrectomies. Synthesis of decorin, biglycan, and procollagen type I mRNAs was evaluated by in situ hybridization. RESULTS: Versican was strongly expressed in cellular crescents and periglomerular areas, whereas decorin and biglycan accumulated in collagen type I-enriched regions, including fibrocellular and fibrous crescents, and interstitial fibrosis. PG and collagen type I accumulation colocalized with myofibroblasts in crescents, periglomerular areas, and interstitium. CONCLUSIONS: The temporal and spatial patterns of expression demonstrated in this study provide evidence to support pathogenic roles for PG in the evolution of CGN. Based on known biological properties of this molecule, versican may facilitate migration of cells in developing crescents. Decorin and biglycan may contribute to progression of CGN, perhaps via interactions with collagen type I in the remodeled extracellular matrix.